Science.gov

Sample records for improves nutrient uptake

  1. Summer cover crops and soil amendments to improve growth and nutrient uptake of okra

    SciTech Connect

    Wang, Q.R.; Li, Y.C.; Klassen, W.

    2006-04-15

    A pot experiment with summer cover crops and soil amendments was conducted in two consecutive years to elucidate the effects of these cover crops and soil amendments on 'Clemson Spineless 80' okra (Abelmoschus esculentus) yields and biomass production, and the uptake and distribution of soil nutrients and trace elements. The cover crops were sunn hemp (Crotalaria juncea), cowpea (Vigna unguiculata), velvetbean (Mucuna deeringiana), and sorghum sudan-grass (Sorghum bicolor x S. bicolor var. sudanense) with fallow as the control. The organic soil amendments were biosolids (sediment from wastewater plants), N-Viro Soil (a mixture of biosolids and coal ash), coal ash (a combustion by-product from power plants), co-compost (a mixture of 3 biosolids: 7 yard waste), and yard waste compost (mainly from leaves and branches of trees and shrubs, and grass clippings) with a soil-incorporated cover crop as the control. As a subsequent vegetable crop, okra was grown after the cover crops, alone or together with the organic soil amendments, had been incorporated. All of the cover crops, except sorghum sudangrass in 2002-03, significantly improved okra fruit yields and the total biomass production. Both cover crops and soil amendments can substantially improve nutrient uptake and distribution. The results suggest that cover crops and appropriate amounts of soil amendments can be used to improve soil fertility and okra yield without adverse environmental effects or risk of contamination of the fruit. Further field studies will be required to confirm these findings.

  2. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

    PubMed Central

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot−1). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot−1) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot−1) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials. PMID:25977938

  3. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances.

    PubMed

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot(-1)). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot(-1)) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot(-1)) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials.

  4. Application of microbial inoculants promote plant growth, increased nutrient uptake and improve root morphology of corn plants

    USDA-ARS?s Scientific Manuscript database

    Reducing fertilizers impacts from agriculture is a world-wide concern, both from an environmental and human health perspective. One way to reduce impacts of fertilizers is by enhancing plant uptake which improves nutrient use efficiency and also potentially reduce the amounts of fertilizer needed. ...

  5. The Role of Diatom Nanostructures in Biasing Diffusion to Improve Uptake in a Patchy Nutrient Environment

    PubMed Central

    Mitchell, James G.; Seuront, Laurent; Doubell, Mark J.; Losic, Dusan; Voelcker, Nicolas H.; Seymour, Justin; Lal, Ratnesh

    2013-01-01

    Background Diatoms are important single-celled autotrophs that dominate most lit aquatic environments and are distinguished by surficial frustules with intricate designs of unknown function. Principal Findings We show that some frustule designs constrain diffusion to positively alter nutrient uptake. In nutrient gradients of 4 to 160 times over <5 cm, the screened-chambered morphology of Coscincodiscus sp. biases the nutrient diffusion towards the cell by at least 3.8 times the diffusion to the seawater. In contrast, the open-chambers of Thalassiosira eccentrica produce at least a 1.3 times diffusion advantage to the membrane over Coscincodiscus sp. when nutrients are homogeneous. Significance Diffusion constraint explains the success of particular diatom species at given times and the overall success of diatoms. The results help answer the unresolved question of how adjacent microplankton compete. Furthermore, diffusion constraint by supramembrane nanostructures to alter molecular diffusion suggests that microbes compete via supramembrane topology, a competitive mechanism not considered by the standard smooth-surface equations used for nutrient uptake nor in microbial ecology and cell physiology. PMID:23667421

  6. Efficacies of designer biochars in improving biomass and nutrient uptake of winter wheat grown in a hard setting subsoil layer.

    PubMed

    Sigua, G C; Novak, J M; Watts, D W; Johnson, M G; Spokas, K

    2016-01-01

    In the Coastal Plains region of the United States, the hard setting subsoil layer of Norfolk soils results in low water holding capacity and nutrient retention, which often limits root development. In this region, the Norfolk soils are under intensive crop production that further depletes nutrients and reduces organic carbon (C). Incorporation of pyrolyzed organic residues or "biochars" can provide an alternative recalcitrant C source. However, biochar quality and effect can be inconsistent and different biochars react differently in soils. We hypothesized that addition of different designer biochars will have variable effects on biomass and nutrient uptake of winter wheat. The objective of this study was to investigate the effects of designer biochars on biomass productivity and nutrient uptake of winter wheat (Triticum aestivum L.) in a Norfolk's hard setting subsoil layer. Biochars were added to Norfolk's hard setting subsoil layer at the rate of 40 Mg ha(-1). The different sources of biochars were: plant-based (pine chips, PC); animal-based (poultry litter, PL); 50:50 blend (50% PC:50% PL); 80:20 blend (80% PC:20% PL); and hardwood (HW). Aboveground and belowground biomass and nutrient uptake of winter wheat varied significantly (p⩽0.0001) with the different designer biochar applications. The greatest increase in the belowground biomass of winter wheat over the control was from 80:20 blend of PC:PL (81%) followed by HW (76%), PC (59%) and 50:50 blend of PC:PL (9%). However, application of PL resulted in significant reduction of belowground biomass by about 82% when compared to the control plants. The average uptake of P, K, Ca, Mg, Na, Al, Fe, Cu and Zn in both the aboveground and belowground biomass of winter wheat varied remarkably with biochar treatments. Overall, our results showed promising significance for the treatment of a Norfolk's hard setting subsoil layer since designer biochars did improve both aboveground/belowground biomass and nutrient uptake

  7. Estimation of stream nutrient uptake from nutrient addition experiments

    SciTech Connect

    Payn, Robert

    2005-09-01

    Nutrient uptake in streams is often quantified by determining nutrient uptake length. However, current methods for measuring nutrient uptake length are often impractical, expensive, or demonstrably incorrect. We have developed a new method to estimate ambient nutrient uptake lengths using field experiments involving several levels of nutrient addition. Data analysis involves plotting nutrient addition uptake lengths versus added concentration and extrapolating to the negative ambient concentration. This method is relatively easy, inexpensive, and based on sound theoretical development. It is more accurate than the commonly used method involving a single nutrient addition. The utility of the method is supported by field studies directly comparing our new method with isotopic tracer methods for determining uptake lengths of phosphorus, ammonium, and nitrate. Our method also provides parameters for comparing potential nutrient limitation among streams.

  8. Dynamic model of flexible phytoplankton nutrient uptake

    PubMed Central

    Bonachela, Juan A.; Raghib, Michael; Levin, Simon A.

    2011-01-01

    The metabolic machinery of marine microbes can be remarkably plastic, allowing organisms to persist under extreme nutrient limitation. With some exceptions, most theoretical approaches to nutrient uptake in phytoplankton are largely dominated by the classic Michaelis–Menten (MM) uptake functional form, whose constant parameters cannot account for the observed plasticity in the uptake apparatus. Following seminal ideas by earlier researchers, we propose a simple cell-level model based on a dynamic view of the uptake process whereby the cell can regulate the synthesis of uptake proteins in response to changes in both internal and external nutrient concentrations. In our flexible approach, the maximum uptake rate and nutrient affinity increase monotonically as the external nutrient concentration decreases. For low to medium nutrient availability, our model predicts uptake and growth rates larger than the classic MM counterparts, while matching the classic MM results for large nutrient concentrations. These results have important consequences for global coupled models of ocean circulation and biogeochemistry, which lack this regulatory mechanism and are thus likely to underestimate phytoplankton abundances and growth rates in oligotrophic regions of the ocean. PMID:22143781

  9. Acetic acid inhibits nutrient uptake in Saccharomyces cerevisiae: auxotrophy confounds the use of yeast deletion libraries for strain improvement.

    PubMed

    Ding, Jun; Bierma, Jan; Smith, Mark R; Poliner, Eric; Wolfe, Carole; Hadduck, Alex N; Zara, Severino; Jirikovic, Mallori; van Zee, Kari; Penner, Michael H; Patton-Vogt, Jana; Bakalinsky, Alan T

    2013-08-01

    Acetic acid inhibition of yeast fermentation has a negative impact in several industrial processes. As an initial step in the construction of a Saccharomyces cerevisiae strain with increased tolerance for acetic acid, mutations conferring resistance were identified by screening a library of deletion mutants in a multiply auxotrophic genetic background. Of the 23 identified mutations, 11 were then introduced into a prototrophic laboratory strain for further evaluation. Because none of the 11 mutations was found to increase resistance in the prototrophic strain, potential interference by the auxotrophic mutations themselves was investigated. Mutants carrying single auxotrophic mutations were constructed and found to be more sensitive to growth inhibition by acetic acid than an otherwise isogenic prototrophic strain. At a concentration of 80 mM acetic acid at pH 4.8, the initial uptake of uracil, leucine, lysine, histidine, tryptophan, phosphate, and glucose was lower in the prototrophic strain than in a non-acetic acid-treated control. These findings are consistent with two mechanisms by which nutrient uptake may be inhibited. Intracellular adenosine triphosphate (ATP) levels were severely decreased upon acetic acid treatment, which likely slowed ATP-dependent proton symport, the major form of transport in yeast for nutrients other than glucose. In addition, the expression of genes encoding some nutrient transporters was repressed by acetic acid, including HXT1 and HXT3 that encode glucose transporters that operate by facilitated diffusion. These results illustrate how commonly used genetic markers in yeast deletion libraries complicate the effort to isolate strains with increased acetic acid resistance.

  10. Nutrient use and uptake in Pinus taeda.

    PubMed

    Albaugh, Timothy J; Allen, H Lee; Fox, Thomas R

    2008-07-01

    We quantified nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) content, use (nutrient amount for one growth year), retranslocation (nutrients recycled before foliage senescence), uptake (use minus retranslocation), volume production per unit of uptake and fertilizer-uptake efficiency (percent applied taken up) in a 2 x 2 (nutrient and water) factorial experiment replicated four times in an 8-year-old loblolly pine (Pinus taeda L.) stand growing on a nutrient-poor sandy soil in Scotland County, North Carolina, USA. Over 14 years, we applied 1140, 168, 393, 168 and 146 kg ha(-1) of elemental N, P, K, Ca and Mg fertilizer, respectively, and an average of 710 mm year(-1) of irrigation. All plots received complete vegetation control. Fertilization about doubled tissue N, P, K and Mg contents at age 21, whereas irrigation resulted in smaller increases in nutrient contents. Maximum annual uptake was 101, 9.3, 44, 37 and 13 kg ha(-1) year(-1) and volume production per unit of nutrient uptake was 0.35, 3.5, 0.66, 1.1 and 3.1 m(3) kg(-1), for N, P, K, Ca and Mg, respectively. Irrigated plots had greater volume production per unit of N, P, K and Mg uptake than control plots, likely because irrigation allowed photosynthesis to continue during dry periods. Fertilized plus irrigated plots had less volume production per unit of these elements than the fertilized plots either because nutrient uptake exceeded the requirement for optimum growth or because available water (rainfall plus irrigation) was insufficient for the leaf area achieved with fertilization. At age 19, fertilizer-uptake efficiencies for N, P, K, Ca and Mg were 53, 24, 62, 57 and 39%, respectively, and increased with irrigation to 68, 36, 78, 116 and 55%, respectively. The scale of fertilizer uptake was likely a result of low native site nutrient availability, study longevity, measurement of all tissue components on site, a comprehensive assessment of coarse roots, and the 3-m rooting

  11. Efficacies of designer biochars in improving biomass and nutrient uptake of winter wheat grown in a hard setting subsoil layer

    USDA-ARS?s Scientific Manuscript database

    In the Coastal Plains region of the United States, the hard setting subsoil layer of Norfolk soils results in low water holding capacity and nutrient retention, which often limits root development. In this region, the Norfolk soils are under intensive crop production that further depletes nutrients ...

  12. Alum application to improve water quality in a municipal wastewater treatment wetland: effects on macrophyte growth and nutrient uptake.

    PubMed

    Malecki-Brown, Lynette M; White, John R; Brix, Hans

    2010-03-01

    Application of low doses of alum to treatment wetlands to reduce elevated outflow winter phosphorus concentrations were tested in mesocosms vegetated with either Typhadomingensis, Schoenoplectus californicus, or submerged aquatic vegetation (SAV) (Najas guadalupensis-dominated). Alum was pumped to experimental units at a rate of 0.91 g Al m(-2) d(-1) and water quality monitored for 3 months. The alum application significantly improved the outflow water quality and overall the growth of the plants was unaffected by the alum application. Biomass and growth varied between species and through time, but no significant effects of alum application were detected. The concentrations of nutrients and mineral elements in the aboveground tissues differed between species and over time, but only the concentration of Al in plant tissue was increased by alum additions. The concentration of Al was 50-fold higher in alum-treated SAV as compared to the control, and in Typha and Schoenoplectus the concentrations were 4- and 2-fold, higher, respectively. The N/P ratios in the plant tissues were low (<10) suggesting that their growth and biomass was limited by nitrogen. The research suggests that a continuous or seasonal low-dosage alum application to treatment wetlands provides an effective tool to maintain discharge concentrations within permitted values during the inefficient winter treatment times. We suggest that the use of alum should be restricted to treatment wetland areas dominated by emergent vegetation as the effects of the elevated Al concentrations in SAV needs further study. 2010 Elsevier Ltd. All rights reserved.

  13. Prospects for optimizing soil microbial functioning to improve plant nutrient uptake and soil carbon sequestration under elevated CO2

    NASA Astrophysics Data System (ADS)

    Nie, M.; Pendall, E. G.

    2013-12-01

    Potential to mitigate climate change through increasing plant productivity and its carbon (C) input to soil may be limited by soil nitrogen (N) availability. Using a novel 13C-CO2 and 15N-soil dual labeling method, we investigated whether plant growth-promoting bacteria would interact with atmospheric CO2 concentration to alter plant productivity and soil C storage. We grew Bouteloua gracilis under ambient (380 ppm) or elevated CO2 (700 ppm) in climate-controlled chambers, and plant individuals were grown with or without Pseudomonas fluorescens inoculum, which can produce N catabolic enzymes. We observed that both eCO2 and P. fluorescens increased plant productivity and its C allocation to soil. P. fluorescens relative to eCO2 enhanced plant N uptake from soil organic matter, which highly correlated with soil N enzyme activities and rhizosphere exudate C. More importantly, P. fluorescens increased microbial biomass and deceased specific microbial respiration in comparison with eCO2. These results indicate that application of plant growth-promoting bacteria can increase microbial C utilization efficiency with subsequent N mineralization from soil organic matter, and may improve plant N availability and soil C sequestration. Together, our findings highlight the potential of plant growth-promoting bacteria for global change mitigation by terrestrial ecosystems.

  14. Endocytotic uptake of nutrients in carnivorous plants.

    PubMed

    Adlassnig, Wolfram; Koller-Peroutka, Marianne; Bauer, Sonja; Koshkin, Edith; Lendl, Thomas; Lichtscheidl, Irene K

    2012-07-01

    Carnivorous plants trap, digest and absorb animals in order to supplement their mineral nutrition. Nutrients absorbed by the plant include different nitrogen species, phosphate, potassium, trace elements and small organic compounds. Uptake is usually thought to be performed via specific channels, but this study provides evidence that endocytosis is involved as well. Traps of the carnivorous plants Nepenthes coccinea, Nepenthes ventrata, Cephalotus follicularis, Drosophyllum lusitanicum, Drosera capensis, Dionaea muscipula, Aldrovanda vesiculosa, Genlisea violacea × lobata, Sarracenia psittacina and Sarracenia purpurea were stained with methylene blue in order to identify possible sites of uptake. The permeable parts of the traps were incubated with fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA) and other fluorescent endocytosis markers, combined with the soluble protein BSA or respiratory inhibitors. Uptake was studied by confocal microscopy. In Nepenthes, small fluorescent vesicles became visible 1 h after incubation with FITC-BSA. These vesicles fused to larger compartments within 30 h. A similar behaviour was found in the related genera Drosera, Dionaea, Aldrovanda and Drosophyllum but also in Cephalotus with glands of different evolutionary origin. In Genlisea and Sarracenia, no evidence for endocytosis was found. We propose that in many carnivorous plants, nutrient uptake by carriers is supplemented by endocytosis, which enables absorption and intracellular digestion of whole proteins. The advantage for the plant of reducing secretion of enzymes for extracellular digestion is evident.

  15. Fertilizer and soil management practices for improving the efficiency of nutrient uptake and use in northern highbush blueberry

    USDA-ARS?s Scientific Manuscript database

    Highbush blueberry is a long-lived perennial crop well-adapted to acidic soils. Plants acquire primarily NH4-N and tolerate relatively low concentrations of P and cations in the soil and high concentrations of plant available metals such as Al and Mn. Recently, we found that optimal leaf nutrient co...

  16. NUTRIENT UPTAKE: A Microcomputer Program to Predict Nutrient Absorption from Soil by Roots.

    ERIC Educational Resources Information Center

    Oates, Kenneth; Barber, S. A.

    1987-01-01

    Discusses the use of a computer program designed to solve the mathematical model associated with soil nutrient uptake by plant roots and to predict the nutrient uptake. Describes a user-friendly personal computer version of this program. (TW)

  17. Sensitivity analysis of a pulse nutrient addition technique for estimating nutrient uptake in large streams

    Treesearch

    Laurence Lin; J.R. Webster

    2012-01-01

    The constant nutrient addition technique has been used extensively to measure nutrient uptake in streams. However, this technique is impractical for large streams, and the pulse nutrient addition (PNA) has been suggested as an alternative. We developed a computer model to simulate Monod kinetics nutrient uptake in large rivers and used this model to evaluate the...

  18. Genetic variation for root architecture, nutrient uptake and mycorrhizal colonisation in Medicago truncatula accessions

    USDA-ARS?s Scientific Manuscript database

    Sustainable agriculture strives for healthy, high yielding plants with minimal agronomic inputs. Genetic solutions to increase nutrient uptake are desirable because they provide ongoing improvements. To achieve this it is necessary to identify genes involved in uptake and translocation of nutrients....

  19. Inoculation of new rhizobial isolates improve nutrient uptake and growth of bean (Phaseolus vulgaris) and arugula (Eruca sativa).

    PubMed

    de Souza, Eduardo M; Bassani, Victor L; Sperotto, Raul A; Granada, Camille E

    2016-08-01

    In the current agricultural model, the massive use of chemical fertilizer causes environmental and economic losses. Inoculation of plant-growth-promoting (PGP) nitrogen-fixing bacteria is an alternative to the use of nitrogen, phosphorus and potassium fertilizers. In this study, rhizobia strains isolated from common bean (Phaseolus vulgaris) root nodules were evaluated in an effort to identify an efficient nitrogen-fixing rhizobia strain able to improve bean germination and growth. Common bean plants were collected from seven sites in southern Brazil, and 210 native rhizobia isolates were obtained. Evaluation of PGP traits showed that most of the rhizobia isolates were non-siderophore producers and weak indolic compounds producers. Under laboratory conditions, rhizobia isolates E15 (Rhizobium leguminosarum) and L5 (Rhizobium radiobacter) increase germination percentage, length, and dry weight of common bean and arugula (Eruca sativa) seedlings. Under greenhouse conditions, common bean plants inoculated with the rhizobia isolates VC28 and L15 (both Rhizobium fabae) presented the highest nodule number and shoot dry matter, while VC28 also presented the highest values of shoot nitrogen and potassium. Isolate L17 presented highly effective N fixation, even with reduced nodulation. These new rhizobia isolates are attractive PGP alternatives to chemical fertilizers. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Nutrient uptake of peanut genotypes under different water regimes

    USDA-ARS?s Scientific Manuscript database

    Drought is a serious environmental stress limiting growth and productivity in peanut and other crops. Nutrient uptake of peanut is reduced under drought conditions, which reduces yield. The objectives of this study were to investigate nutrient uptake of peanut genotypes in response to drought and ...

  1. Nutrient uptake and mineralization during leaf decay in streams - a model simulation

    SciTech Connect

    Webster, Jackson; Newbold, J. Denis; Thomas, Steve; Valett, H. Maurice; Mulholland, Patrick J

    2009-01-01

    We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of decomposition, while mineralization may produce increases in concentrations during later stages of decomposition. The simulations also showed that initial nutrient content of the leaves can affect the stream nutrient concentration dynamics and determine whether nitrogen or phosphorus is the limiting nutrient. Finally, the simulations suggest a net retention (uptake > mineralization) of nutrients in headwater streams, which is balanced by export of particulate organic nutrients to downstream reaches. Published studies support the conclusion that uptake can substantially change stream nutrient concentrations. On the other hand, there is little published evidence that mineralization also affects nutrient concentrations. Also, there is little information on direct microbial utilization of nutrients contained in the decaying leaves themselves. Our results suggest several directions for research that will improve our understanding of the complex relationship between leaf decay and nutrient dynamics in streams.

  2. Microbial enzyme activity, nutrient uptake and nutrient limitation in forested streams

    Treesearch

    Brian H. Hill; Frank H. McCormick; Bret C. Harvey; Sherri L. Johnson; Melvin L. Warren; Colleen M. Elonen

    2010-01-01

    The flow of organic matter and nutrients from catchments into the streams draining them and the biogeochemical transformations of organic matter and nutrients along flow paths are fundamental processes instreams (Hynes,1975; Fisher, Sponseller & Heffernan, 2004). Microbial biofilms are often the primary interface for organic matter and nutrient uptake and...

  3. A new compensated root water and nutrient uptake model implemented in HYDRUS programs

    NASA Astrophysics Data System (ADS)

    Simunek, Jiri; Hopmans, Jan W.; Lazarovitch, Naftali

    2010-05-01

    Plant root water and nutrient uptake is one of the most important processes in subsurface unsaturated flow and transport modeling, as root uptake controls actual plant evapotranspiration, water recharge and nutrient leaching to the groundwater. Root water uptake in unsaturated flow models is usually uncompensated and nutrient uptake is simulated assuming that all uptake is passive. We present a new compensated root water and nutrient uptake model, implemented in HYDRUS programs. The so-called root adaptability factor (Jarvis, 1989) is used to represent a threshold value above which reduced root water or nutrient uptake in water- or nutrient-stressed parts of the root zone is fully compensated for by increased uptake in other soil regions that are less stressed. Using a critical value of the water stress index, water uptake compensation is proportional to the water stress response function. Total root nutrient uptake is determined from the total of active and passive nutrient uptake. The partitioning between passive and active uptake is controlled by the a priori defined concentration value c_max. Passive nutrient uptake is simulated by multiplying root water uptake with the dissolved nutrient concentration, for soil solution concentration values below c_max. Passive nutrient uptake is thus zero when c_max is equal to zero. As the active nutrient uptake is obtained from the difference between plant nutrient demand and passive nutrient uptake (using Michaelis-Menten kinetics), the presented model thus implies that reduced passive nutrient uptake is compensated for by active nutrient uptake. In addition, the proposed root uptake model includes compensation for active nutrient uptake, in a similar way as used for root water uptake. The proposed root water and nutrient uptake model is demonstrated by several hypothetical and real examples, for plants supplied by water due to capillary rise from groundwater and surface drip irrigation.

  4. Hardwood seeding root and nutrient parameters for a model of nutrient uptake.

    PubMed

    Kelly, J M; Scarbrough, J D; Mays, P A

    2001-01-01

    Use of mechanistic models is an increasingly accepted way to evaluate complex processes. The Barber-Cushman model provides a means to simulate nutrient uptake once information on root system characteristics, nutrient uptake, and soil nutrient supply are developed. Objectives of this study were to determine during a growing season: (i) root growth for 1-yr-old black cherry (Prunus serotina Ehrh.), northern red oak (Quercus rubra L.), and red maple (Acer rubrum L.) seedlings; (ii) net plant increase in N, P, K, Ca, and Mg; (iii) soil solution and solid phase nutrient concentrations; and (iv) the influence of root growth and soil nutrient supply changes on nutrient uptake using the Barber-Cushman model. Seedlings were grown in pots containing A horizon soil from two forest sites. Measurements were made on five occasions during the growing season. Root growth averaged 41.5 cm d-1 for red maple compared with 28.0 and 16.7 cm d-1 for cherry and oak, respectively. Seventy-five percent of root growth occurred at the end of the growing season. Total plant N showed the greatest change (25-58%) due to soil source. Model simulations underestimated observed uptake by 31 to 99%. A clear relationship between soil solution nutrient concentration and plant uptake, an important assumption of the model, was not observed. Results indicate care will need to be exercised in the development and use of root growth and nutrient supply values in mechanistic models.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  6. Through form to function: root hair development and nutrient uptake

    NASA Technical Reports Server (NTRS)

    Gilroy, S.; Jones, D. L.

    2000-01-01

    Root hairs project from the surface of the root to aid nutrient and water uptake and to anchor the plant in the soil. Their formation involves the precise control of cell fate and localized cell growth. We are now beginning to unravel the complexities of the molecular interactions that underlie this developmental regulation. In addition, after years of speculation, nutrient transport by root hairs has been demonstrated clearly at the physiological and molecular level, with evidence for root hairs being intense sites of H(+)-ATPase activity and involved in the uptake of Ca(2+), K(+), NH(4)(+), NO(3)(-), Mn(2+), Zn(2+), Cl(-) and H(2)PO(4)(-).

  7. Optimizing Nutrient Uptake in Biological Transport Networks

    NASA Astrophysics Data System (ADS)

    Ronellenfitsch, Henrik; Katifori, Eleni

    2013-03-01

    Many biological systems employ complex networks of vascular tubes to facilitate transport of solute nutrients, examples include the vascular system of plants (phloem), some fungi, and the slime-mold Physarum. It is believed that such networks are optimized through evolution for carrying out their designated task. We propose a set of hydrodynamic governing equations for solute transport in a complex network, and obtain the optimal network architecture for various classes of optimizing functionals. We finally discuss the topological properties and statistical mechanics of the resulting complex networks, and examine correspondence of the obtained networks to those found in actual biological systems.

  8. Polyamines Confer Salt Tolerance in Mung Bean (Vigna radiata L.) by Reducing Sodium Uptake, Improving Nutrient Homeostasis, Antioxidant Defense, and Methylglyoxal Detoxification Systems.

    PubMed

    Nahar, Kamrun; Hasanuzzaman, Mirza; Rahman, Anisur; Alam, Md Mahabub; Mahmud, Jubayer-Al; Suzuki, Toshisada; Fujita, Masayuki

    2016-01-01

    The physiological roles of PAs (putrescine, spermidine, and spermine) were investigated for their ability to confer salt tolerance (200 mM NaCl, 48 h) in mung bean seedlings (Vigna radiata L. cv. BARI Mung-2). Salt stress resulted in Na toxicity, decreased K, Ca, Mg, and Zn contents in roots and shoots, and disrupted antioxidant defense system which caused oxidative damage as indicated by increased lipid peroxidation, H2O2 content, [Formula: see text] generation rate, and lipoxygenase activity. Salinity-induced methylglyoxal (MG) toxicity was also clearly evident. Salinity decreased leaf chlorophyll (chl) and relative water content (RWC). Supplementation of salt affected seedlings with exogenous PAs enhanced the contents of glutathione and ascorbate, increased activities of antioxidant enzymes (dehydroascorbate reductase, glutathione reductase, catalase, and glutathione peroxidase) and glyoxalase enzyme (glyoxalase II), which reduced salt-induced oxidative stress and MG toxicity, respectively. Exogenous PAs reduced cellular Na content and maintained nutrient homeostasis and modulated endogenous PAs levels in salt affected mung bean seedlings. The overall salt tolerance was reflected through improved tissue water and chl content, and better seedling growth.

  9. Polyamines Confer Salt Tolerance in Mung Bean (Vigna radiata L.) by Reducing Sodium Uptake, Improving Nutrient Homeostasis, Antioxidant Defense, and Methylglyoxal Detoxification Systems

    PubMed Central

    Nahar, Kamrun; Hasanuzzaman, Mirza; Rahman, Anisur; Alam, Md. Mahabub; Mahmud, Jubayer-Al; Suzuki, Toshisada; Fujita, Masayuki

    2016-01-01

    The physiological roles of PAs (putrescine, spermidine, and spermine) were investigated for their ability to confer salt tolerance (200 mM NaCl, 48 h) in mung bean seedlings (Vigna radiata L. cv. BARI Mung-2). Salt stress resulted in Na toxicity, decreased K, Ca, Mg, and Zn contents in roots and shoots, and disrupted antioxidant defense system which caused oxidative damage as indicated by increased lipid peroxidation, H2O2 content, O2•- generation rate, and lipoxygenase activity. Salinity-induced methylglyoxal (MG) toxicity was also clearly evident. Salinity decreased leaf chlorophyll (chl) and relative water content (RWC). Supplementation of salt affected seedlings with exogenous PAs enhanced the contents of glutathione and ascorbate, increased activities of antioxidant enzymes (dehydroascorbate reductase, glutathione reductase, catalase, and glutathione peroxidase) and glyoxalase enzyme (glyoxalase II), which reduced salt-induced oxidative stress and MG toxicity, respectively. Exogenous PAs reduced cellular Na content and maintained nutrient homeostasis and modulated endogenous PAs levels in salt affected mung bean seedlings. The overall salt tolerance was reflected through improved tissue water and chl content, and better seedling growth. PMID:27516763

  10. Impact of FGD gypsum on soil fertility and plant nutrient uptake

    USDA-ARS?s Scientific Manuscript database

    Use of FGD gypsum is thought to improve soil productivity and increase plant production. Thus, a study was conducted to evaluate the effects of FGD gypsum on yield, plant nutrient uptake and soil productivity. The study was conducted on an established bermudagrass pasture. Poultry litter was applied...

  11. Estimating uncertainty in ambient and saturation nutrient uptake metrics from nutrient pulse releases in stream ecosystems

    SciTech Connect

    Brooks, Scott C.; Brandt, Craig C.; Griffiths, Natalie A.

    2016-10-07

    Nutrient spiraling is an important ecosystem process characterizing nutrient transport and uptake in streams. Various nutrient addition methods are used to estimate uptake metrics; however, uncertainty in the metrics is not often evaluated. A method was developed to quantify uncertainty in ambient and saturation nutrient uptake metrics estimated from saturating pulse nutrient additions (Tracer Additions for Spiraling Curve Characterization; TASCC). Using a Monte Carlo (MC) approach, the 95% confidence interval (CI) was estimated for ambient uptake lengths (Sw-amb) and maximum areal uptake rates (Umax) based on 100,000 datasets generated from each of four nitrogen and five phosphorous TASCC experiments conducted seasonally in a forest stream in eastern Tennessee, U.S.A. Uncertainty estimates from the MC approach were compared to the CIs estimated from ordinary least squares (OLS) and non-linear least squares (NLS) models used to calculate Sw-amb and Umax, respectively, from the TASCC method. The CIs for Sw-amb and Umax were large, but were not consistently larger using the MC method. Despite the large CIs, significant differences (based on nonoverlapping CIs) in nutrient metrics among seasons were found with more significant differences using the OLS/NLS vs. the MC method. Lastly, we suggest that the MC approach is a robust way to estimate uncertainty, as the calculation of Sw-amb and Umax violates assumptions of OLS/NLS while the MC approach is free of these assumptions. The MC approach can be applied to other ecosystem metrics that are calculated from multiple parameters, providing a more robust estimate of these metrics and their associated uncertainties.

  12. Estimating uncertainty in ambient and saturation nutrient uptake metrics from nutrient pulse releases in stream ecosystems

    SciTech Connect

    Brooks, Scott C.; Brandt, Craig C.; Griffiths, Natalie A.

    2016-10-07

    Nutrient spiraling is an important ecosystem process characterizing nutrient transport and uptake in streams. Various nutrient addition methods are used to estimate uptake metrics; however, uncertainty in the metrics is not often evaluated. A method was developed to quantify uncertainty in ambient and saturation nutrient uptake metrics estimated from saturating pulse nutrient additions (Tracer Additions for Spiraling Curve Characterization; TASCC). Using a Monte Carlo (MC) approach, the 95% confidence interval (CI) was estimated for ambient uptake lengths (Sw-amb) and maximum areal uptake rates (Umax) based on 100,000 datasets generated from each of four nitrogen and five phosphorous TASCC experiments conducted seasonally in a forest stream in eastern Tennessee, U.S.A. Uncertainty estimates from the MC approach were compared to the CIs estimated from ordinary least squares (OLS) and non-linear least squares (NLS) models used to calculate Sw-amb and Umax, respectively, from the TASCC method. The CIs for Sw-amb and Umax were large, but were not consistently larger using the MC method. Despite the large CIs, significant differences (based on nonoverlapping CIs) in nutrient metrics among seasons were found with more significant differences using the OLS/NLS vs. the MC method. Lastly, we suggest that the MC approach is a robust way to estimate uncertainty, as the calculation of Sw-amb and Umax violates assumptions of OLS/NLS while the MC approach is free of these assumptions. The MC approach can be applied to other ecosystem metrics that are calculated from multiple parameters, providing a more robust estimate of these metrics and their associated uncertainties.

  13. Estimating uncertainty in ambient and saturation nutrient uptake metrics from nutrient pulse releases in stream ecosystems

    DOE PAGES

    Brooks, Scott C.; Brandt, Craig C.; Griffiths, Natalie A.

    2016-10-07

    Nutrient spiraling is an important ecosystem process characterizing nutrient transport and uptake in streams. Various nutrient addition methods are used to estimate uptake metrics; however, uncertainty in the metrics is not often evaluated. A method was developed to quantify uncertainty in ambient and saturation nutrient uptake metrics estimated from saturating pulse nutrient additions (Tracer Additions for Spiraling Curve Characterization; TASCC). Using a Monte Carlo (MC) approach, the 95% confidence interval (CI) was estimated for ambient uptake lengths (Sw-amb) and maximum areal uptake rates (Umax) based on 100,000 datasets generated from each of four nitrogen and five phosphorous TASCC experiments conductedmore » seasonally in a forest stream in eastern Tennessee, U.S.A. Uncertainty estimates from the MC approach were compared to the CIs estimated from ordinary least squares (OLS) and non-linear least squares (NLS) models used to calculate Sw-amb and Umax, respectively, from the TASCC method. The CIs for Sw-amb and Umax were large, but were not consistently larger using the MC method. Despite the large CIs, significant differences (based on nonoverlapping CIs) in nutrient metrics among seasons were found with more significant differences using the OLS/NLS vs. the MC method. Lastly, we suggest that the MC approach is a robust way to estimate uncertainty, as the calculation of Sw-amb and Umax violates assumptions of OLS/NLS while the MC approach is free of these assumptions. The MC approach can be applied to other ecosystem metrics that are calculated from multiple parameters, providing a more robust estimate of these metrics and their associated uncertainties.« less

  14. Biotechnology of nutrient uptake and assimilation in plants.

    PubMed

    López-Arredondo, Damar L; Leyva-González, Marco A; Alatorre-Cobos, Fulgencio; Herrera-Estrella, Luis

    2013-01-01

    Plants require a complex balance of mineral nutrients to reproduce successfully. Because the availability of many of these nutrients in the soil is compromised by several factors, such as soil pH, cation presence, and microbial activity, crop plants depend directly on nutrients applied as fertilizers to achieve high yields. However, the excessive use of fertilizers is a major environmental concern due to nutrient leaching that causes water eutrophication and promotes toxic algae blooms. This situation generates the urgent need for crop plants with increased nutrient use efficiency and better-designed fertilization schemes. The plant biology revolution triggered by the development of efficient gene transfer systems for plant cells together with the more recent development of next-generation DNA and RNA sequencing and other omics platforms have advanced considerably our understanding on the molecular basis of plant nutrition and how plants respond to nutritional stress. To date, genes encoding sensors, transcription factors, transporters, and metabolic enzymes have been identified as potential candidates to improve nutrient use efficiency. In addition, the study of other genetic resources, such as bacteria and fungi, allows the identification of alternative mechanisms of nutrient assimilation, which are potentially applicable in plants. Although significant progress in this respect has been achieved by conventional breeding, in this review we focus on the biotechnological approaches reported to date aimed at boosting the use of the three most limiting nutrients in the majority of arable lands: nitrogen, phosphorus, and iron.

  15. Uptake of perfluorinated compounds by plants grown in nutrient solution.

    PubMed

    García-Valcárcel, A I; Molero, E; Escorial, M C; Chueca, M C; Tadeo, J L

    2014-02-15

    The uptake rates of three perfluorinated carboxylates and three perfluorinated sufonates by a grass (B diandrus) grown in nutrient solution at two different perfluorinated compounds (PFCs) concentrations were assessed. Grass can be ingested by grazing animals causing the PFCs to enter the food chain, which is a pathway of human exposure to these compounds. A rapid and miniaturized method was developed to determine PFCs in plants, based on a matrix solid-phase dispersion (MSPD) extraction procedure followed by quantitation by HPLC-MS/MS with an MQL in the range from 1 to 9 ng/g. An increase of PFCs levels in plant was observed along the exposure time. Differences in uptake for studied perfluorinated carboxylates were found, showing a decrease with carbon chain length (from 3027 to 1,167 ng/g at the end of assay), whereas no significant differences in absorption were obtained between perfluorinated sulfonates (about 1,700 ng/g). Initially, higher PFC transfer factors (ratio between concentration in plant and concentration in initial nutrient solution) were obtained for plants growing in the nutrient solution at the highest PFC concentration, but these factors became similar with time to plants exposed to the lowest concentration. © 2013 Elsevier B.V. All rights reserved.

  16. Predictive modeling of transient storage and nutrient uptake: Implications for stream restoration

    USGS Publications Warehouse

    O'Connor, Ben L.; Hondzo, Miki; Harvey, Judson

    2010-01-01

    This study examined two key aspects of reactive transport modeling for stream restoration purposes: the accuracy of the nutrient spiraling and transient storage models for quantifying reach-scale nutrient uptake, and the ability to quantify transport parameters using measurements and scaling techniques in order to improve upon traditional conservative tracer fitting methods. Nitrate (NO3–) uptake rates inferred using the nutrient spiraling model underestimated the total NO3– mass loss by 82%, which was attributed to the exclusion of dispersion and transient storage. The transient storage model was more accurate with respect to the NO3– mass loss (±20%) and also demonstrated that uptake in the main channel was more significant than in storage zones. Conservative tracer fitting was unable to produce transport parameter estimates for a riffle-pool transition of the study reach, while forward modeling of solute transport using measured/scaled transport parameters matched conservative tracer breakthrough curves for all reaches. Additionally, solute exchange between the main channel and embayment surface storage zones was quantified using first-order theory. These results demonstrate that it is vital to account for transient storage in quantifying nutrient uptake, and the continued development of measurement/scaling techniques is needed for reactive transport modeling of streams with complex hydraulic and geomorphic conditions.

  17. Including carrier-mediated transport in oral uptake prediction of nutrients and pharmaceuticals in humans.

    PubMed

    O'Connor, Isabel A; Veltman, Karin; Huijbregts, Mark A J; Ragas, Ad M J; Russel, Frans G M; Hendriks, A Jan

    2014-11-01

    Most toxicokinetic models consider passive diffusion as the only mechanism when modeling the oral uptake of chemicals. However, the overall uptake of nutrients and xenobiotics, such as pharmaceuticals and environmental pollutants, can be increased by influx transport proteins. We incorporated carrier-mediated transport into a one-compartment toxicokinetic model originally developed for passive diffusion only. The predictions were compared with measured oral uptake efficiencies of nutrients and pharmaceuticals, i.e. the fraction of the chemical reaching systemic circulation. Including carrier-mediated uptake improved model predictions for hydrophilic nutrients (RMSE=10% vs. 56%, Coefficient of Efficiency CoE=0.5 vs. -9.6) and for pharmaceuticals (RMSE=21% vs. 28% and CoE=-0.4 vs. -1.1). However, the negative CoE for pharmaceuticals indicates that further improvements are needed. Most important in this respect is a more accurate estimation of vMAX and KM as well as the determination of the amount of expressed and functional transport proteins both in vivo and in vitro. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Research Paper. Nutrient uptake and mineralization during leaf decay in streams-a model simulation.

    Treesearch

    J.R. Webster; J.D. Newbold; S.A. Thomas; H.M. Valett; P.J. Mulholland

    2009-01-01

    We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of...

  19. Can uptake length in strams be determined by nutrient addition experiments? Results from an interbiome comparison study

    Treesearch

    P. J Mulholland; J. L. Tanks; J. R. Webster; W. B. Bowden; W. K Dodds; S. V. Gregory; N. B Grimm; J. L. Meriam; J. L. Meyer; B. J. Peterson; H. M. Valett; W. M. Wollheim

    2002-01-01

    Nutrient uptake length is an important parnmeter tor quantifying nutrient cycling in streams. Although nutrient tracer additions are the preierred method for measuring uptake length under ambient nutrient concentrations, short-term nutrient addition experiments have more irequently been used to estimate uptake length in streams. Theoretical analysis of the relationship...

  20. Hydrologic and biologic influences on stream network nutrient concentrations: Interactions of hydrologic turnover and concentration-dependent nutrient uptake

    NASA Astrophysics Data System (ADS)

    Mallard, John; McGlynn, Brian; Covino, Tim

    2016-04-01

    Stream networks lie in a crucial landscape position between terrestrial ecosystems and downstream water bodies. As such, whether inferring terrestrial watershed processes from watershed outlet nutrient signals or predicting the effect of observed terrestrial processes on stream nutrient signals, it is requisite to understand how stream networks can modulate terrestrial nutrient inputs. To date integrated understanding and modeling of physical and biological influences on nutrient concentrations at the stream network scale have been limited. However, watershed scale groundwater - surface water exchange (hydrologic turnover), concentration-variable biological uptake, and the interaction between the two can strongly modify stream water nutrient concentrations. Stream water and associated nutrients are lost to and replaced from groundwater with distinct nutrient concentrations while in-stream nutrients can also be retained by biological processes at rates that vary with concentration. We developed an empirically based network scale model to simulate the interaction between hydrologic turnover and concentration-dependent nutrient uptake across stream networks. Exchange and uptake parameters were measured using conservative and nutrient tracer addition experiments in the Bull Trout Watershed, central Idaho. We found that the interaction of hydrologic turnover and concentration-dependent uptake combined to modify and subsequently stabilize in-stream concentrations, with specific concentrations dependent on the magnitude of hydrologic turnover, groundwater concentrations, and the shape of nutrient uptake kinetic curves. We additionally found that by varying these physical and biological parameters within measured ranges we were able to generate a spectrum of stream network concentration distributions representing a continuum of shifting magnitudes of physical and biological influences on in-stream concentrations. These findings elucidate the important and variable role of

  1. Hydrologic and biologic influences on stream network nutrient concentrations: Interactions of hydrologic turnover and concentration-dependent nutrient uptake

    NASA Astrophysics Data System (ADS)

    Mallard, J. M.; McGlynn, B. L.; Covino, T. P.; Bergstrom, A.

    2012-12-01

    Stream networks lie in a crucial landscape position between terrestrial ecosystems and downstream water bodies. As such, whether inferring terrestrial watershed processes from watershed outlet nutrient signals or predicting the effect of observed terrestrial processes on stream nutrient signals, it is requisite to understand how stream networks can modulate terrestrial nutrient inputs. To date integrated understanding and modeling of physical and biological influences on nutrient concentrations at the stream network scale have been limited. However, watershed scale groundwater - surface water exchange (hydrologic turnover), concentration-variable biological uptake, and the interaction between the two can strongly modify stream water nutrient concentrations. Stream water and associated nutrients are lost to and replaced from groundwater with a distinct nutrient concentrations while in-stream nutrients can also be retained by biological processes at rates that vary with concentration. We developed an empirically based network scale model to simulate the interaction between hydrologic turnover and concentration-dependent nutrient uptake across stream networks. Exchange and uptake parameters were measured using conservative and nutrient tracer addition experiments in the Bull Trout Watershed, central Idaho. We found that the interaction of hydrologic turnover and concentration-dependent uptake combined to modify and subsequently stabilize in-stream concentrations, with specific concentrations dependent on the magnitude of hydrologic turnover, groundwater concentrations, and the shape of nutrient uptake kinetic curves. We additionally found that by varying these physical and biological parameters within measured ranges we were able to generate a spectrum of stream network concentration distributions representing a continuum of shifting magnitudes of physical and biological influences on in-stream concentrations. These findings elucidate the important and variable role

  2. Toward a transport-based analysis of nutrient spiraling and uptake in streams

    USGS Publications Warehouse

    Runkel, Robert L.

    2007-01-01

    Nutrient addition experiments are designed to study the cycling of nutrients in stream ecosystems where hydrologic and nonhydrologic processes determine nutrient fate. Because of the importance of hydrologic processes in stream ecosystems, a conceptual model known as nutrient spiraling is frequently employed. A central part of the nutrient spiraling approach is the determination of uptake length (SW), the average distance traveled by dissolved nutrients in the water column before uptake. Although the nutrient spiraling concept has been an invaluable tool in stream ecology, the current practice of estimating uptake length from steady-state nutrient data using linear regression (called here the "SW approach") presents a number of limitations. These limitations are identified by comparing the exponential SW equation with analytical solutions of a stream solute transport model. This comparison indicates that (1) SW, is an aggregate measure of uptake that does not distinguish between main channel and storage zone processes, (2) SW, is an integrated measure of numerous hydrologie and nonhydrologic processes-this process integration may lead to difficulties in interpretation when comparing estimates of SW, and (3) estimates of uptake velocity and areal uptake rate (Vf and U) based on S W, are not independent of system hydrology. Given these findings, a transport-based approach to nutrient spiraling is presented for steady-state and time-series data sets. The transport-based approach for time-series data sets is suggested for future research on nutrient uptake as it provides a number of benefits, including the ability to (1) separately quantify main channel and storage zone uptake, (2) quantify specific hydrologic and nonhydrologic processes using various model parameters (process separation), (3) estimate uptake velocities and areal uptake rates that are independent of hydrologic effects, and (4) use short-term, non-plateau nutrient additions such that the effects of

  3. Optimizing simulated fertilizer additions using a genetic algorithm with a nutrient uptake model

    Treesearch

    Wendell P. Cropper; N.B. Comerford

    2005-01-01

    Intensive management of pine plantations in the southeastern coastal plain typically involves weed and pest control, and the addition of fertilizer to meet the high nutrient demand of rapidly growing pines. In this study we coupled a mechanistic nutrient uptake model (SSAND, soil supply and nutrient demand) with a genetic algorithm (GA) in order to estimate the minimum...

  4. One-time tillage of no-till: Effects on nutrients, mycorrhizae, and phosphorus uptake

    USDA-ARS?s Scientific Manuscript database

    Stratification of nutrient availability, especially of P, that develops with continuous no-till (NT) can affect runoff nutrient concentration and possibly nutrient uptake. The effects of composted manure application and one-time tillage of NT on the distribution of soil chemical properties, root co...

  5. Coupled Effects of Hyporheic Flow Structure and Metabolic Pattern on Reach-scale Nutrient Uptake

    NASA Astrophysics Data System (ADS)

    Li, A.; Aubeneau, A. F.; Bolster, D.; Tank, J. L.; Packman, A. I.

    2015-12-01

    Co-injections of conservative tracers and nutrients are commonly used to assess net reach-scale nutrient transformation rates and benthic/hyporheic uptake parameters. However, little information is available on spatial metabolic patterns in the benthic and hyporheic regions. Based on observations from real systems, we used particle tracking simulations to explore the effects of localized metabolism on estimates of reach-scale nutrient uptake rates. Metabolism locally depletes nutrient concentrations relative to conservative tracers, causing their concentration profiles of injected nutrients and conservative tracers to diverge. At slow rates of hyporheic exchange relative to rates of metabolism, overall hyporheic nutrient uptake is limited by delivery from the stream, and effective reach-scale nutrient uptake parameters will be controlled by the hyporheic exchange rate. At high rates of hyporheic exchange relative to rates of metabolism, the injected tracer can propagate beyond regions of high microbial activity, which commonly occur near the streambed surface. In this case, the injected tracer may not adequately capture timescales of nutrient replenishment in the most bioactive regions. Reach-scale nutrients uptake rate increases with increasing heterogeneity in local metabolic patterns, altering the shape of breakthrough curves downstream. More observations of hyporheic rates and metabolic patterns are needed to understand how flow heterogeneity and reaction heterogeneity interact to control nutrient dynamics at reach-scale.

  6. Nutrient Uptake Changes in Ascorbate Free Radical-Stimulated Onion Roots.

    PubMed Central

    Gonzalez-Reyes, J. A.; Hidalgo, A.; Caler, J. A.; Palos, R.; Navas, P.

    1994-01-01

    Long-term treatments with ascorbate free radical-stimulated glucose, fucose, sucrose, and nitrate uptake in Allium cepa roots. Glucose and fucose showed saturation kinetics in untreated roots, but after treatment with the ascorbate free radical, uptake was linear with time. Although the rates of nitrate and sucrose uptake increased after treatment with ascorbate free radical, the kinetics were similar to those observed in the controls. Ascorbate and dehydroascorbate inhibited nutrient uptake. The uptake rates for all nutrients increased throughout the 48-h period of pretreatment with ascorbate free radical. During the treatment an increase in the vacuole volume and tonoplast surface area also occurred. These results show the relationship between an increase in vacuolar volume and stimulated nutrient uptake from ascorbate-free radical, resulting in enhanced root elongation. These results suggest that activation of a transplasma membrane redox system by ascorbate-free radical is involved in these responses. PMID:12232078

  7. Effect of Nutrient/Carbon Supplements on Biological Phosphate and Nitrate Uptake by Protozoan Isolates

    NASA Astrophysics Data System (ADS)

    Akpor, O. B.; Momba, M. N. B.; Okonkwo, J.

    This study was aimed at investigating the effect of nine different nutrient/carbon supplements in mixed liquor on nutrient uptake ability of three wastewater protozoan isolates, which have previously been screened for phosphate and nitrate uptake efficiency. The results revealed that over 50% of phosphate was removed in the presence of sodium acetate, glucose or sucrose. Similarly, nitrate uptake of over 60% was observed in the presence of sodium acetate, sodium succinate, glucose or sucrose. These trends were common in all the isolates. Chemical Oxygen Demand (COD) removal in the mixed liquor was only found to be significantly removed in mixed liquors that were supplemented with glucose, sucrose or sodium succinate. In the presence of sodium acetate, COD was observed to increase. The findings of this investigation have revealed that nutrient uptake and COD removal by the test protozoan isolates may be dependent primarily on the initial nutrient supplement in mixed liquor.

  8. Late effects of abdominal radiation on intestinal uptake of nutrients

    SciTech Connect

    Thomson, A.B.; Cheeseman, C.I.; Walker, K.

    1986-09-01

    The late effects of variable doses of abdominal irradiation on in vitro jejunal uptake were examined. The uptake of glucose, galactose, cholic acid, medium-chain length fatty acids, and decanol was studied 6 and 33 weeks following 300, 600, or 900 cGy abdominal irradiation. The intestinal morphological characteristics were similar 6 and 33 weeks after radiation. The uptake of cholic acid was unaffected by abdominal irradiation, but for glucose, galactose, and four fatty acids the direction and magnitude of the changes in uptake were influenced by the dose of irradiation and by the interval following exposure. The greater uptake of decanol at 6 weeks but lower uptake of decanol at 33 weeks reflected changes in the resistance of the intestinal unstirred water layer. These absorption changes suggest that the intestine may not be capable of correcting the transport abnormalities arising from sublethal doses of abdominal irradiation.

  9. Nutrient uptake and distribution in young Pinot noir grapevines over two seasons

    USDA-ARS?s Scientific Manuscript database

    The seasonal timing of biomass and nutrient uptake and distribution among different vine organs was determined over two growing seasons in 4-year-old Pinot noir grapevines carrying their first full crop and grown in field microplots. Vines were fertilized in spring and the biomass and nutrient conte...

  10. Exponential fertilization of Pinus monticola seedlings: nutrient uptake efficiency, leaching fractions, and early outplanting performance

    Treesearch

    R. Kasten Dumroese; Deborah S. Page-Dumroese; K. Francis Salifu; Douglass F. Jacobs

    2005-01-01

    We evaluated nutrient uptake efficiency and subsequent leaching fractions for western white pine (Pinus monticola Dougl. ex D. Don) seedlings grown with exponentially increasing or conventional (constant) fertilization in a greenhouse. Conventional fertilization was associated with higher leachate electrical conductivity and greater nutrient losses,...

  11. Sequential nutrient uptake as a potential mechanism for phytoplankton to maintain high primary productivity and balanced nutrient stoichiometry

    NASA Astrophysics Data System (ADS)

    Yin, Kedong; Liu, Hao; Harrison, Paul J.

    2017-05-01

    We hypothesize that phytoplankton have the sequential nutrient uptake strategy to maintain nutrient stoichiometry and high primary productivity in the water column. According to this hypothesis, phytoplankton take up the most limiting nutrient first until depletion, continue to draw down non-limiting nutrients and then take up the most limiting nutrient rapidly when it is available. These processes would result in the variation of ambient nutrient ratios in the water column around the Redfield ratio. We used high-resolution continuous vertical profiles of nutrients, nutrient ratios and on-board ship incubation experiments to test this hypothesis in the Strait of Georgia. At the surface in summer, ambient NO3- was depleted with excess PO43- and SiO4- remaining, and as a result, both N : P and N : Si ratios were low. The two ratios increased to about 10 : 1 and 0. 45 : 1, respectively, at 20 m. Time series of vertical profiles showed that the leftover PO43- continued to be removed, resulting in additional phosphorus storage by phytoplankton. The N : P ratios at the nutricline in vertical profiles responded differently to mixing events. Field incubation of seawater samples also demonstrated the sequential uptake of NO3- (the most limiting nutrient) and then PO43- and SiO4- (the non-limiting nutrients). This sequential uptake strategy allows phytoplankton to acquire additional cellular phosphorus and silicon when they are available and wait for nitrogen to become available through frequent mixing of NO3- (or pulsed regenerated NH4). Thus, phytoplankton are able to maintain high productivity and balance nutrient stoichiometry by taking advantage of vigorous mixing regimes with the capacity of the stoichiometric plasticity. To our knowledge, this is the first study to show the in situ dynamics of continuous vertical profiles of N : P and N : Si ratios, which can provide insight into the in situ dynamics of nutrient stoichiometry in the water column and the inference of

  12. NPKS uptake, sensing, and signaling and miRNAs in plant nutrient stress.

    PubMed

    Nath, Manoj; Tuteja, Narendra

    2016-05-01

    Sessile nature of higher plants consequently makes it highly adaptable for nutrient absorption and acquisition from soil. Plants require 17 essential elements for their growth and development which include 14 minerals (macronutrients: N, P, K, Mg, Ca, S; micronutrients: Cl, Fe, B, Mn, Zn, Cu, Ni, Mo) and 3 non-mineral (C, H, O) elements. The roots of higher plants must acquire these macronutrients and micronutrients from rhizosphere and further allocate to other plant parts for completing their life cycle. Plants evolved an intricate series of signaling and sensing cascades to maintain nutrient homeostasis and to cope with nutrient stress/availability. The specific receptors for nutrients in root, root system architecture, and internal signaling pathways help to develop plasticity in response to the nutrient starvation. Nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) are essential for various metabolic processes, and their deficiency negatively effects the plant growth and yield. Genes coding for transporters and receptors for nutrients as well as some small non-coding RNAs have been implicated in nutrient uptake and signaling. This review summarizes the N, P, K, and S uptake, sensing and signaling events in nutrient stress condition especially in model plant Arabidopsis thaliana and involvement of microRNAs in nutrient deficiency. This article also provides a framework of uptake, sensing, signaling and to highlight the microRNA as an emerging major players in nutrient stress condition. Nutrient-plant-miRNA cross talk may help plant to cope up nutrient stress, and understanding their precise mechanism(s) will be necessary to develop high yielding smart crop with low nutrient input.

  13. [Effects of rhizosphere soil permeability on water and nutrient uptake by maize].

    PubMed

    Niu, Wen-quan; Guo, Chao

    2010-11-01

    Aimed to better understand the significance of soil microenvironment in crop growth, a pot experiment was conducted to investigate the effects of rhizosphere soil permeability on the water and nutrient uptake by maize. Under three irrigation levels (600, 400, and 200 ml per pot), three treatments of soil aeration (no tube aeration as the control, tube aeration every two days, and tube aeration every four days) were installed, and the physiological indices of maize were measured. Under the same irrigation levels, soil aeration increased the plant height, leaf area, chlorophyll contents, promoted nutrient adsorption and increased root vitality markedly. At elongation stage, treatment tube aeration every four days had the highest root vitality (8.24 mg x g(-1) x h(-1)) under the irrigation level 600 ml per pot, being significantly higher (66.7%) than that (4.94 mg x g(-1) x h(-1)) of the control. Soil aeration had no significant effects on the transpiration rate of maize, indicating that rhizosphere soil aeration could raise water and nutrient use efficiency, and improve maize growth.

  14. Effects of arginine on intestinal epithelial cell integrity and nutrient uptake.

    PubMed

    Xia, Mi; Ye, Lulu; Hou, Qihang; Yu, Qinghua

    2016-11-14

    Arginine is a multifaceted amino acid that is critical to the normal physiology of the gastrointestinal tract. Oral arginine administration has been shown to improve mucosal recovery following intestinal injury. The present study investigated the influence of extracellular arginine concentrations on epithelial cell barrier regulation and nutrition uptake by porcine small intestinal epithelial cell line (IPEC-J2). The results show that reducing arginine concentration from 0·7 to 0·2 mm did not affect the transepithelial electrical resistance value, tight-junction proteins (claudin-1, occludin, E-cadherin), phosphorylated extracellular signal-regulated protein kinases (p-ERK) and mucin-1 expression. Furthermore, reducing arginine concentration stimulated greater expression of cationic amino acid transporter (CAT1), excitatory amino acid transporter (EAAT3) and alanine/serine/cysteine transporter (ASCT1) mRNA by IPEC-J2 cells, which was verified by elevated efficiency of amino acid uptake. Glucose consumption by IPEC-J2 cells treated with 0·2 mm-arginine remained at the same physiological level to guarantee energy supply and to maintain the cell barrier. This experiment implied that reducing arginine concentration is feasible in IPEC-J2 cells guaranteed by nutrient uptake and cell barrier function.

  15. Cation uptake and allocation by red pine seedlings under cation-nutrient stress in a column growth experiment

    USDA-ARS?s Scientific Manuscript database

    Background and aims: Plant nutrient uptake is affected by environmental stress, but how plants respond to cation nutrient stress is poorly understood. We assessed the impact of varying degrees of cation-nutrient stress on cation uptake in an experimental plant-mineral system. Methods: Column experim...

  16. Microbial Enzyme Activity, Nutrient Uptake, and Nutrient Limitation in Forested Streams

    EPA Science Inventory

    We measured NH4 + and PO4 -3 uptake length (Sw), uptake velocity (Vf), uptake rate (U), biofilm enzyme activity (BEA), and channel geomorphology in streams draining forested catchments in the Northwestern (Northern California Coast Range and Cascade Mountains) and Southeastern (A...

  17. Microbial Enzyme Activity, Nutrient Uptake, and Nutrient Limitation in Forested Streams

    EPA Science Inventory

    We measured NH4 + and PO4 -3 uptake length (Sw), uptake velocity (Vf), uptake rate (U), biofilm enzyme activity (BEA), and channel geomorphology in streams draining forested catchments in the Northwestern (Northern California Coast Range and Cascade Mountains) and Southeastern (A...

  18. Poor Aeration Curtails Slash Pine Root Growth and Nutrient Uptake

    Treesearch

    Eugene Shoulders

    1976-01-01

    Slash pine may absorb nutrients and water best in spring and early summer because soil moisture, soil aeration, and temperature are apparently optimum at this time. One-year-old slash pine seedlings maintained at a high oxygen level grew about 1% times as many roots as were produced at a low oxygen level. No other environmental conditions significantly influenced root...

  19. Mycorrhiza and PGPB modulate maize biomass, nutrient uptake and metabolic pathways in maize grown in mining-impacted soil.

    PubMed

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2015-12-01

    Abiotic stress factors including poor nutrient content and heavy metal contamination in soil, can limit plant growth and productivity. The main goal of our study was to evaluate element uptake, biomass and metabolic responses in maize roots growing in mining-impacted soil with the combination of arbuscular mycorrhiza (My) and plant growth promoting bacteria (PGPB/B). Maize plants subjected to PGPB, My and combined treatments showed a significant increase in biomass and uptake of some elements in shoot and root. Metabolite analysis identified 110 compounds that were affected ≥2-fold compared to control, with 69 metabolites upregulated in the My group, 53 metabolites in the My+B group and 47 metabolites in B group. Pathway analysis showed that impact on glyoxylate and dicarboxylate metabolism was common between My and My+B groups, whereas PGPB group showed a unique effect on fatty acid biosynthesis with significant increase in palmitic acid and stearic acid. Differential regulation of some metabolites by mycorrhizal treatment correlated with root biomass while PGPB regulated metabolites correlated with biomass increase in shoot. Overall, the combination of rhizospheric microorganisms used in our study significantly increased maize nutrient uptake and growth relative to control. The changes in metabolic pathways identified during the symbiotic interaction will improve our understanding of mechanisms involved in rhizospheric interactions that are responsible for increased growth and nutrient uptake in crop plants.

  20. Nutrient Uptake and Metabolism Along a Large Scale Tropical Physical-Chemical Gradient

    NASA Astrophysics Data System (ADS)

    Tromboni, F.; Neres-Lima, V.; Saltarelli, W. A.; Miwa, A. C. P.; Cunha, D. G. F.

    2016-12-01

    Nutrient spiraling is a whole-system approach for estimating nutrient uptake that can be used to assess aquatic ecosystems' responses to environmental change and anthropogenic impacts. Historically research on nutrient dynamic uptake in streams has focused on single nutrient dynamics and only rarely the stoichiometric uptake has been considered and linked to carbon metabolism driven by autotrophic and heterotrophic production. We investigated the relationship between uptake of phosphate (PO43-), nitrate (NO3-) ammonium (NH4+) and total dissolve nitrogen (DIN)/ PO43-; and gross primary production (GPP), respiration (R), and net ecosystem productivity (NEP) in six relatively pristine streams with differences regarding canopy cover and physical characteristics, located in a large scale gradient from tropical Atlantic Forest to an Atlantic forest/Cerrado (Brazilian Savanna) transition. We carried out whole stream instantaneous additions of PO43-, NO3- and NH4+ added to each stream in combination, using the TASCC (Tracer Additions for Spiraling Curve Characterization) method. Metabolism measurements were performed in the same streams right after uptake was measured, using one-station open channel method and re-aeration estimations for those sites. We found different background concentrations in the streams located in the Atlantic forest compared with the transition area with Cerrado. In general PO43- and NO3- uptake increased with the decreasing of canopy cover, while a positive relation with background concentration better explained NH4+uptake. DIN/PO43- uptake increased with increasing R and NEP. Little work on functional characteristics of pristine streams has been conducted in this region and this work provides an initial characterization on nitrogen and phosphorus dynamics as well as their stoichiometric uptake in streams.

  1. Discontinuities in stream nutrient uptake below lakes in mountain drainage networks

    USGS Publications Warehouse

    Arp, C.D.; Baker, M.A.

    2007-01-01

    In many watersheds, lakes and streams are hydrologically linked in spatial patterns that influence material transport and retention. We hypothesized that lakes affect stream nutrient cycling via modifications to stream hydrogeomorphology, source-waters, and biological communities. We tested this hypothesis in a lake district of the Sawtooth Mountains, Idaho. Uptake of NO3- and PO4-3 was compared among 25 reaches representing the following landscape positions: lake inlets and outlets, reaches >1-km downstream from lakes, and reference reaches with no nearby lakes. We quantified landscape-scale hydrographic and reach-scale hydrogeomorphic, source-water, and biological variables to characterize these landscape positions and analyze relationships to nutrient uptake. Nitrate uptake was undetectable at most lake outlets, whereas PO4-3 uptake was higher at outlets as compared to reference and lake inlet reaches. Patterns in nutrient demand farther downstream were similar to lake outlets with a gradual shift toward reference-reach functionality. Nitrate uptake was most correlated to sediment mobility and channel morphology, whereas PO 4-3 uptake was most correlated to source-water characteristics. The best integrated predictor of these patterns in nutrient demand was % contributing area (the proportion of watershed area not routing through a lake). We estimate that NO3- and PO 4-3 demand returned to 50% of pre-lake conditions within 1-4-km downstream of a small headwater lake and resetting of nutrient demand was slower downstream of a larger lake set lower in a watershed. Full resetting of these nutrient cycling processes was not reached within 20-km downstream, indicating that lakes can alter stream ecosystem functioning at large spatial scales throughout mountain watersheds. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

  2. Nitrate uptake varies with tide height and nutrient availability in the intertidal seaweed Fucus vesiculosus.

    PubMed

    Benes, Kylla M; Bracken, Matthew E S

    2016-10-01

    Intertidal seaweeds must cope with a suite of stressors imposed by aerial exposure at low tide, including nutrient limitation due to emersion. Seaweeds can access nutrients only when submerged, so individuals living higher compared to lower on the shore may have adaptations allowing them to acquire sufficient amounts of nutrients to survive and maintain growth. Using a combination of observations and experiments, we aimed to identify intraspecific variation in nitrate uptake rates across the intertidal distribution of F. vesiculosus, as well as test for acclimation in response to a change in tide height. We replicated our study at sites spanning nearly the entire Gulf of Maine coastline, to examine how local environmental variability may alter intraspecific variation in nitrate uptake. We found that average nitrate uptake rates were ~18% higher in upper compared to lower intertidal Fucus vesiculosus. Furthermore, we found evidence for both acclimation and adaptation to tide height during a transplant experiment. F. vesiculosus transplanted from the lower to the upper intertidal zone was characterized by increased nitrate uptake, but individuals transplanted from the upper to the lower intertidal zone retained high uptake rates. Our observations differed among Gulf of Maine regions and among time points of our study. Importantly, these differences may reflect associations between nitrate uptake rates and abiotic environmental conditions and seaweed nutrient status. Our study highlights the importance of long-term variation in ambient nutrient supply in driving intraspecific variation of seaweeds across the intertidal gradient and local and seasonal variation in ambient nutrient levels in mediating intraspecific differences.

  3. Fractionated low doses of abdominal irradiation alters jejunal uptake of nutrients

    SciTech Connect

    Thomson, A.B.; Keelan, M.; Cheeseman, C.I.; Walker, K.

    1986-06-01

    Abdominal radiation is associated with changes in intestinal uptake of nutrients that begins within three days and persist for over 33 weeks. Clinically, fractionated doses of radiation (FDR) are used in an attempt to minimize the complications of this therapy, but the effects of fractionated doses of radiation on intestinal transport have not been defined. An in vitro technique was used to assess the jejunal and ileal uptake of varying concentrations of glucose and leucine, as well as the uptake of single concentrations of fatty acids and decanol in rats exposed 3, 7, and 14 days previously to a course of 200 cGy given on each of five consecutive days. FDR was associated with an increase in the uptake of decanol, and therefore a decrease in the effective resistance of the unstirred water layer. FDR had a variable effect on the uptake of glucose and leucine, with a decline in the value of the Michaelis constant (Km) and the passive permeability coefficient for glucose (Pd), whereas the Km for leucine was unchanged and the Pd for leucine was variably affected by FDR. The maximal transport rate (Jdm) for leucine progressively rose following FDR, whereas the Jdm for glucose initially rose, then fell. The uptake of galactose and medium chain-length fatty acids was unchanged by FDR, whereas the jejunal uptake of myristic acid rose, and the uptake of cholic acid declined, then returned to normal. FDR was associated with greater body weight gain and jejunal and ileal weight. The changes in nutrient uptake following FDR differed from the absorption changes occurring after a single dose of radiation. Thus, fractionated doses of abdominal radiation produce complex changes in the intestinal uptake of actively and passively transported nutrients, and these variable changes are influenced by the time following radiation exposure and by the solute studied.

  4. Dissolved inorganic carbon enhanced growth, nutrient uptake, and lipid accumulation in wastewater grown microalgal biofilms.

    PubMed

    Kesaano, Maureen; Gardner, Robert D; Moll, Karen; Lauchnor, Ellen; Gerlach, Robin; Peyton, Brent M; Sims, Ronald C

    2015-03-01

    Microalgal biofilms grown to evaluate potential nutrient removal options for wastewaters and feedstock for biofuels production were studied to determine the influence of bicarbonate amendment on their growth, nutrient uptake capacity, and lipid accumulation after nitrogen starvation. No significant differences in growth rates, nutrient removal, or lipid accumulation were observed in the algal biofilms with or without bicarbonate amendment. The biofilms possibly did not experience carbon-limited conditions because of the large reservoir of dissolved inorganic carbon in the medium. However, an increase in photosynthetic rates was observed in algal biofilms amended with bicarbonate. The influence of bicarbonate on photosynthetic and respiration rates was especially noticeable in biofilms that experienced nitrogen stress. Medium nitrogen depletion was not a suitable stimulant for lipid production in the algal biofilms and as such, focus should be directed toward optimizing growth and biomass productivities to compensate for the low lipid yields and increase nutrient uptake. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Sudden increase in atmospheric CO2 concentration reveals strong coupling between shoot carbon uptake and root nutrient uptake in young walnut trees.

    PubMed

    Delaire, Mickaël; Frak, Ela; Sigogne, Monique; Adam, Boris; Beaujard, François; Le Roux, Xavier

    2005-02-01

    We studied the short-term (i.e., a few days) effect of a sudden increase in CO2 uptake by shoots on nutrient (NO3-, P ion, K+, Ca2+ and Mg2+) uptake by roots during vegetative growth of young walnut (Juglans nigra x J. major L.) trees. The increase in CO2 uptake was induced by a sudden increase in atmospheric CO2 concentration ([CO2]). Twelve 2-year-old trees were transplanted and grown in perlite-filled pots in a greenhouse. Rates of CO2 uptake and water loss by individual trees were determined by a branch bag method from 3 days before until 6 days after [CO2] was increased. Nutrient uptake rates were measured concurrently by a hydroponic recirculating nutrient solution system that provided non-limiting supplies of water and nutrients. Six control trees were kept in ambient [CO2] (360 ppm), and [CO2] was increased to 550 ppm for one set of three trees and to 800 ppm for another set of three trees. Before imposing the elevated [CO2] treatments, all trees exhibited similar daily water loss, CO2 uptake and nutrient uptake rates when expressed per unit leaf area to account for the tree size effect. Daily water loss rates were only slightly affected by elevated [CO2]. Carbon dioxide uptake rates greatly increased with increasing atmospheric [CO2], and nutrient uptake rates were proportional to CO2 uptake rates during the study period, except for P ion. Our results show that, despite the important carbon and nitrogen storage capacities previously observed in young walnut trees, nutrient uptake by roots is strongly coupled to carbon uptake by shoots over periods of a few days.

  6. Effects of light intensity and temperature on Cryptomonas ovata (Cryptophyceae) growth and nutrient uptake rates

    USGS Publications Warehouse

    Cloern, James E.

    1977-01-01

    Specific growth rate of Cryptomonas ovata var. palustris Pringsheim was measured in batch culture at 14 light-temperature combinations. Both the maximum growth rate (μm) and optimum light intensity (Iopt) fit an empirical function that increases exponentially with temperature up to an optimum (Topt), then declines rapidly as temperature exceeds Topt. Incorporation of these functions into Steele's growth equation gives a good estimate of specific growth rate over a wide range of temperature and light intensity. Rates of phosphate, ammonium and nitrate uptake were measured separately at 16 combinations of irradiance and temperature and following a spike addition of all starved cells initially took up nutrient at a rapid rate. This transitory surge was followed by a period of steady, substrate-saturated uptake that persisted until external nutrient concentration fell. Substrate-saturated NO3−-uptake proceeded at very slow rates in the dark and was stimulated by both increased temperature and irradiance; NH4+-uptake apparently proceeded at a basal rate at 8 and l4 C and was also stimulated by increased temperature and irradiance. Rates of NH4−-uptake were much higher than NO3−-uptake at all light-temperature combinations. Below 20 C, PO4−3-uptake was more rapid in dark than in light, but was light enhanced at 26 C.

  7. Seasonal Growth and Uptake of Nutrients by Orchardgrass Irrigated with Wastewater,

    DTIC Science & Technology

    1981-05-01

    501Herron, G.M., D.W. Grimes and I.T. Musick (1963) Effects of to 35 to 40 days during the second harvest soil moisture and nitrogen fertilization of...facsimile catalog card in Library of Congress MARC format is reproduced below. Palazzo, A.J. Seasonal growth and uptake of nutrients by orchardgrass irrigated

  8. Nutrient uptake, biomass yield and quantitative analysis of aliphatic aldehydes in cilantro plants

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to evaluate the nutrient uptake, biomass production and yield of the major compounds in the essential oil of five genotypes of Coriandrum sativum L. The treatments were four accessions donated by the National Genetic Resources Advisory Council (NGRAC), U.S. Department...

  9. Nutrient uptake and loss by container-grown deciduous and evergreen Rhododendron nursery plants

    USDA-ARS?s Scientific Manuscript database

    The influence of N fertilizer application on plant uptake and demand for other nutrients was evaluated from May 2005 to February 2006 in container-grown evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ). Increased N-availability incre...

  10. Low transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand.

    PubMed

    Sheibley, Richard W; Duff, John H; Tesoriero, Anthony J

    2014-11-01

    We used mass load budgets, transient storage modeling, and nutrient spiraling metrics to characterize nitrate (NO), ammonium (NH), and inorganic phosphorus (SRP) demand in seven agricultural streams across the United States and to identify in-stream services that may control these conditions. Retention of one or all nutrients was observed in all but one stream, but demand for all nutrients was low relative to the mass in transport. Transient storage metrics (/, , , and ) correlated with NO retention but not NH or SRP retention, suggesting in-stream services associated with transient storage and stream water residence time could influence reach-scale NO demand. However, because the fraction of median reach-scale travel time due to transient storage () was ≤1.2% across the sites, only a relatively small demand for NO could be generated by transient storage. In contrast, net uptake of nutrients from the water column calculated from nutrient spiraling metrics were not significant at any site because uptake lengths calculated from background nutrient concentrations were statistically insignificant and therefore much longer than the study reaches. These results suggest that low transient storage coupled with high surface water NO inputs have resulted in uptake efficiencies that are not sufficient to offset groundwater inputs of N. Nutrient retention has been linked to physical and hydrogeologic elements that drive flow through transient storage areas where residence time and biotic contact are maximized; however, our findings indicate that similar mechanisms are unable to generate a significant nutrient demand in these streams relative to the loads. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. Low transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand

    USGS Publications Warehouse

    Sheibley, Rich W.; Duff, John H.; Tesoriero, Anthony J.

    2014-01-01

    We used mass load budgets, transient storage modeling, and nutrient spiraling metrics to characterize nitrate (NO3−), ammonium (NH4+), and inorganic phosphorus (SRP) demand in seven agricultural streams across the United States and to identify in-stream services that may control these conditions. Retention of one or all nutrients was observed in all but one stream, but demand for all nutrients was low relative to the mass in transport. Transient storage metrics (As/A, Fmed200, Tstr, and qs) correlated with NO3− retention but not NH4+ or SRP retention, suggesting in-stream services associated with transient storage and stream water residence time could influence reach-scale NO3− demand. However, because the fraction of median reach-scale travel time due to transient storage (Fmed200) was ≤1.2% across the sites, only a relatively small demand for NO3− could be generated by transient storage. In contrast, net uptake of nutrients from the water column calculated from nutrient spiraling metrics were not significant at any site because uptake lengths calculated from background nutrient concentrations were statistically insignificant and therefore much longer than the study reaches. These results suggest that low transient storage coupled with high surface water NO3− inputs have resulted in uptake efficiencies that are not sufficient to offset groundwater inputs of N. Nutrient retention has been linked to physical and hydrogeologic elements that drive flow through transient storage areas where residence time and biotic contact are maximized; however, our findings indicate that similar mechanisms are unable to generate a significant nutrient demand in these streams relative to the loads.

  12. Astrocytic Insulin Signaling Couples Brain Glucose Uptake with Nutrient Availability.

    PubMed

    García-Cáceres, Cristina; Quarta, Carmelo; Varela, Luis; Gao, Yuanqing; Gruber, Tim; Legutko, Beata; Jastroch, Martin; Johansson, Pia; Ninkovic, Jovica; Yi, Chun-Xia; Le Thuc, Ophelia; Szigeti-Buck, Klara; Cai, Weikang; Meyer, Carola W; Pfluger, Paul T; Fernandez, Ana M; Luquet, Serge; Woods, Stephen C; Torres-Alemán, Ignacio; Kahn, C Ronald; Götz, Magdalena; Horvath, Tamas L; Tschöp, Matthias H

    2016-08-11

    We report that astrocytic insulin signaling co-regulates hypothalamic glucose sensing and systemic glucose metabolism. Postnatal ablation of insulin receptors (IRs) in glial fibrillary acidic protein (GFAP)-expressing cells affects hypothalamic astrocyte morphology, mitochondrial function, and circuit connectivity. Accordingly, astrocytic IR ablation reduces glucose-induced activation of hypothalamic pro-opio-melanocortin (POMC) neurons and impairs physiological responses to changes in glucose availability. Hypothalamus-specific knockout of astrocytic IRs, as well as postnatal ablation by targeting glutamate aspartate transporter (GLAST)-expressing cells, replicates such alterations. A normal response to altering directly CNS glucose levels in mice lacking astrocytic IRs indicates a role in glucose transport across the blood-brain barrier (BBB). This was confirmed in vivo in GFAP-IR KO mice by using positron emission tomography and glucose monitoring in cerebral spinal fluid. We conclude that insulin signaling in hypothalamic astrocytes co-controls CNS glucose sensing and systemic glucose metabolism via regulation of glucose uptake across the BBB.

  13. Heat Stress Decreases Levels of Nutrient-Uptake and -Assimilation Proteins in Tomato Roots

    PubMed Central

    Giri, Anju; Heckathorn, Scott; Mishra, Sasmita; Krause, Charles

    2017-01-01

    Global warming will increase root heat stress, which is already common under certain conditions. Effects of heat stress on root nutrient uptake have rarely been examined in intact plants, but the limited results indicate that heat stress will decrease it; no studies have examined heat-stress effects on the concentration of nutrient-uptake proteins. We grew Solanum lycopersicum (tomato) at 25 °C/20 °C (day/night) and then transferred some plants for six days to 35 °C /30 °C (moderate heat) or 42 °C/37 °C (severe heat) (maximum root temperature = 32 °C or 39 °C, respectively); plants were then moved back to control conditions for seven days to monitor recovery. In a second experiment, plants were grown for 15 days at 28 °C/23 °C, 32 °C/27 °C, 36 °C/31 °C, and 40 °C/35 °C (day/night). Concentrations of nutrient-uptake and -assimilation proteins in roots were determined using protein-specific antibodies and ELISA (enzyme-linked immunosorbent assay). In general, (1) roots were affected by heat more than shoots, as indicated by decreased root:shoot mass ratio, shoot vs. root %N and C, and the level of nutrient metabolism proteins vs. less sensitive photosynthesis and stomatal conductance; and (2) negative effects on roots were large and slow-to-recover only with severe heat stress (40 °C–42 °C). Thus, short-term heat stress, if severe, can decrease total protein concentration and levels of nutrient-uptake and -assimilation proteins in roots. Hence, increases in heat stress with global warming may decrease crop production, as well as nutritional quality, partly via effects on root nutrient relations. PMID:28106834

  14. Heat Stress Decreases Levels of Nutrient-Uptake and -Assimilation Proteins in Tomato Roots.

    PubMed

    Giri, Anju; Heckathorn, Scott; Mishra, Sasmita; Krause, Charles

    2017-01-19

    Global warming will increase root heat stress, which is already common under certain conditions. Effects of heat stress on root nutrient uptake have rarely been examined in intact plants, but the limited results indicate that heat stress will decrease it; no studies have examined heat-stress effects on the concentration of nutrient-uptake proteins. We grew Solanum lycopersicum (tomato) at 25 °C/20 °C (day/night) and then transferred some plants for six days to 35 °C /30 °C (moderate heat) or 42 °C/37 °C (severe heat) (maximum root temperature = 32 °C or 39 °C, respectively); plants were then moved back to control conditions for seven days to monitor recovery. In a second experiment, plants were grown for 15 days at 28 °C/23 °C, 32 °C/27 °C, 36 °C/31 °C, and 40 °C/35 °C (day/night). Concentrations of nutrient-uptake and -assimilation proteins in roots were determined using protein-specific antibodies and ELISA (enzyme-linked immunosorbent assay). In general, (1) roots were affected by heat more than shoots, as indicated by decreased root:shoot mass ratio, shoot vs. root %N and C, and the level of nutrient metabolism proteins vs. less sensitive photosynthesis and stomatal conductance; and (2) negative effects on roots were large and slow-to-recover only with severe heat stress (40 °C-42 °C). Thus, short-term heat stress, if severe, can decrease total protein concentration and levels of nutrient-uptake and -assimilation proteins in roots. Hence, increases in heat stress with global warming may decrease crop production, as well as nutritional quality, partly via effects on root nutrient relations.

  15. 2-D clinorotation alters the uptake of some nutrients in Arabidopsis thaliana.

    PubMed

    Polinski, Ellen; Schueler, Oliver; Krause, Lars; Wimmer, Monika A; Hemmersbach, Ruth; Goldbach, Heiner E

    2017-05-01

    Future long-term spaceflight missions rely on bioregenerative life support systems (BLSS) in order to provide the required resources for crew survival. Higher plants provide an essential part since they supply food and oxygen and recycle carbon dioxide. There are indications that under space conditions plants might be inefficient regarding the uptake, transport and distribution of nutrients, which in turn affects growth and metabolism. Therefore, Arabidopsis thaliana (Col-0) seeds were germinated and grown for five days under fast clinorotation (2-D clinostat, 60rpm) in order to simulate microgravity. Concentrations of ten different nutrients (potassium, sulfur, phosphorus, calcium, sodium, magnesium, manganese, iron, zinc, and boron) in shoots of plants grown under reduced and normal (1g) gravity conditions were compared. A protocol was developed for the determination of different nutrients by means of inductively coupled plasma optical emission spectrometry (ICPOES), flame emission spectrometry and spectrophotometry. The concentrations of boron and sulfur were significantly decreased in clinorotated shoots, while the concentration of sodium was elevated, suggesting that altered gravity conditions differentially affected nutrient uptake. Possible mechanisms for such effects include reduced transpiration, altered expression of channels or transporters and direct effects on nutrient assimilation. The observed nutrient imbalances might have a negative impact on plant growth and nutritional quality during prolonged space missions. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Staining with 0.05% neutral red reduces nutrient uptake by wheat roots.

    PubMed

    Trolove, Stephen; Tan, Yong; Reid, Jeff

    2015-11-01

    A number of studies have used a 0.05% solution of neutral red to stain live roots so that short term root growth could be measured. These studies, which used a 5 or 10 min staining time, report no effects of the stain on plant properties such as growth, respiration, or nitrate uptake. This paper reports on two experiments conducted to determine whether this staining technique, with a 15 min stain time, affected macronutrient uptake of 6- and 7-week-old wheat (Triticum aestivum L.) plants grown in solution culture. The results showed that, compared with unstained controls, staining plants with 0.05% neutral red halted or halved nitrate uptake measured over a 4 h period the following day. Potassium uptake was also significantly reduced by staining. In the experiment with smaller plants nutrient uptake rate recovered 5 days after staining, but not in the second experiment with larger plants. Stained roots were 19% narrower than unstained roots, suggesting that the stain affected the root structure. We do not recommend the use of 0.05% neutral red staining, for wheat at least, in experiments where accurate measurement of nutrient uptake rate is important.

  17. Scaling plant nitrogen use and uptake efficiencies in response to nutrient addition in peatlands

    SciTech Connect

    Iversen, Colleen M; Bridgham, Scott; Kellogg, Laurie E.

    2010-01-01

    Nitrogen (N) is the primary growth-limiting nutrient in many terrestrial ecosystems, and therefore plant production per unit N taken up (i.e., N use efficiency, NUE) is a fundamentally important component of ecosystem function. Nitrogen use efficiency comprises two components: N productivity (AN, plant production per peak biomass N content) and the mean residence time of N in plant biomass (MRTN). We utilized a five-year fertilization experiment to examine the manner in which increases in N and phosphorus (P) availability affected plant NUE at multiple biological scales (i.e., from leaf to community level). We fertilized a natural gradient of nutrient-limited peatland ecosystems in the Upper Peninsula of Michigan, USA, with 6 g Nm2yr1, 2 g Pm2yr1, or a combination of N and P. Our objectives were to determine how changes in carbon and N allocation within a plant to leaf and woody tissue and changes in species composition within a community, both above- and belowground, would affect (1) NUE; (2) the adaptive trade-off between the components of NUE; (3) the efficiency with which plants acquired N from the soil (N uptake efficiency); and (4) plant community production per unit soil N availability (N response efficiency, NRE). As expected, N and P addition generally increased aboveground production and N uptake. In particular, P availability strongly affected the way in which plants took up and used N. Nitrogen use efficiency response to nutrient addition was not straightforward. Nitrogen use efficiency differed between leaf and woody tissue, among species, and across the ombrotrophic minerotrophic gradient because plants and communities were adapted to maximize either AN or MRTN, but not both concurrently. Increased N availability strongly decreased plant and community N uptake efficiency, while increased P availability increased N uptake efficiency, particularly in a nitrogen-fixing shrub. Nitrogen uptake efficiency was more important in controlling overall plant

  18. Scaling plant nitrogen use and uptake efficiencies in response to nutrient addition in peatlands.

    PubMed

    Iversen, Colleen M; Bridgham, Scott D; Kellogg, Laurie E

    2010-03-01

    Nitrogen (N) is the primary growth-limiting nutrient in many terrestrial ecosystems, and therefore plant production per unit N taken up (i.e., N use efficiency, NUE) is a fundamentally important component of ecosystem function. Nitrogen use efficiency comprises two components: N productivity (A(N), plant production per peak biomass N content) and the mean residence time of N in plant biomass (MRT(N)). We utilized a five-year fertilization experiment to examine the manner in which increases in N and phosphorus (P) availability affected plant NUE at multiple biological scales (i.e., from leaf to community level). We fertilized a natural gradient of nutrient-limited peatland ecosystems in the Upper Peninsula of Michigan, USA, with 6 g N x m(-2) x yr(-1), 2 g P x m(-2) x yr(-1), or a combination of N and P. Our objectives were to determine how changes in carbon and N allocation within a plant to leaf and woody tissue and changes in species composition within a community, both above- and belowground, would affect (1) NUE; (2) the adaptive trade-off between the components of NUE; (3) the efficiency with which plants acquired N from the soil (N uptake efficiency); and (4) plant community production per unit soil N availability (N response efficiency, NRE). As expected, N and P addition generally increased aboveground production and N uptake. In particular, P availability strongly affected the way in which plants took up and used N. Nitrogen use efficiency response to nutrient addition was not straightforward. Nitrogen use efficiency differed between leaf and woody tissue, among species, and across the ombrotrophic-minerotrophic gradient because plants and communities were adapted to maximize either A(N) or MRT(N), but not both concurrently. Increased N availability strongly decreased plant and community N uptake efficiency, while increased P availability increased N uptake efficiency, particularly in a nitrogen-fixing shrub. Nitrogen uptake efficiency was more important

  19. Antimony uptake by Zea mays (L.) and Helianthus annuus (L.) from nutrient solution.

    PubMed

    Tschan, Martin; Robinson, Brett; Schulin, Rainer

    2008-04-01

    We investigated the extent of Sb uptake by maize (Zea mays) and sunflower (Helianthus annuus) from nutrient solutions containing concentrations from 3 to 24 mg/L of potassium antimonate, with the aim of determining the potential of Sb to enter the food chain. The maximum shoot Sb concentrations in Z. mays and H. annuus were 41 mg/kg and 77 mg/kg dry weight, respectively. There was no significant difference in Sb uptake between species. The average bioaccumulation coefficients (the plant/solution concentration quotients) were 1.02 and 1.93 for Z. mays and H. annuus, respectively. Phosphate addition did not affect plant growth or Sb uptake. Antimony uptake by both Z. mays and H. annuus is unlikely to pose a health risk to animals and humans.

  20. Plant growth-promoting rhizobacteria affect the growth and nutrient uptake of Fraxinus americana container seedlings.

    PubMed

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-05-01

    Plant growth-promoting rhizobacteria (PGPR) are important catalysts that regulate the functional properties of agricultural systems. However, there is little information on the effect of PGPR inoculation on the growth and nutrient accumulation of forest container seedlings. This study determined the effects of a growth medium inoculated with PGPR on the nutrient uptake, nutrient accumulation, and growth of Fraxinus americana container seedlings. PGPR inoculation with fertilizer increased the dry matter accumulation of the F. americana aerial parts with delayed seedling emergence time. Under fertilized conditions, the accumulation time of phosphorous (P) and potassium (K) in the F. americana aerial parts was 13 days longer due to PGPR inoculation. PGPR increased the maximum daily P and K accumulations in fertilized seedlings by 9.31 and 10.44 %, respectively, but had little impact on unfertilized ones. Regardless of fertilizer application, the root exudates, namely sugars, amino acids, and organic acids significantly increased because of PGPR inoculation. PGPR inoculation with fertilizer increased the root, shoot, and leaf yields by 19.65, 22.94, and 19.44 %, respectively, as well as the P and K contents by 8.33 and 10.60 %, respectively. Consequently, the N, P, and K uptakes increased by 19.85, 31.97, and 33.95 %, respectively. Hence, PGPR inoculation with fertilizer can be used as a bioenhancer for plant growth and nutrient uptake in forest container seedling nurseries.

  1. The relationship between light intensity and nutrient uptake kinetics in six freshwater diatoms.

    PubMed

    Shi, Pengling; Shen, Hong; Wang, Wenjing; Chen, Wenjie; Xie, Ping

    2015-08-01

    In order to find effective measures to control diatom blooms, a better understanding of the physiological characteristics of nutrient uptake in diatoms is needed. A study of P and Si-uptake kinetics for diatom species from two light regimes was conducted at low (LL), moderate (ML) and high light intensities (HL) (2, 25 and 80 μmol photons/(m(2)·sec)), respectively. The results showed that P uptake of diatoms was heavily influenced by historic light regimes. P affinity changed with growth and photosynthetic activity. The lowest half saturation constant for P uptake (Km(P)) was under HL for high-light adapted diatoms while the lowest half-saturation constant for low-light adapted diatoms was observed under LL. The Si half-saturation constant (Km(Si)) increased with increasing light intensities for pennate diatoms but decreased for centric diatoms. Diatom volumes were correlated with the maximum Si uptake rates (Vm(Si)) at HL and Km(Si) at ML and HL for six diatom species. Our results imply that when we assess the development of diatom blooms we should consider light intensity and cell volume in addition to ambient Si or P concentration. The relationship between light intensity and P-uptake suggests that we can find suitable methods to control diatom blooms on the basis of reducing phytoplankton activity of P-uptake and photosynthesis simultaneously.

  2. Salix arctica changes root distribution and nutrient uptake in response to subsurface nutrients in High Arctic deserts.

    PubMed

    Muller, Amanda L; Hardy, Sarah P; Mamet, Steven D; Ota, Mitsuaki; Lamb, Eric G; Siciliano, Steven D

    2017-08-01

    Moisture is critical for plant success in polar deserts but not by the obvious pathway of reduced water stress. We hypothesized that an indirect, nutrient-linked, pathway resulting from unique water/frozen soil interactions in polar deserts creates nutrient-rich patches critical for plant growth. These nutrient-rich patches (diapirs) form deep in High Arctic polar deserts soils from water accumulating at the permafrost freezing front and ultimately rising into the upper soil horizons through cryoturbated convective landforms (frost boils). To determine if diapirs provide an enhanced source of plant-available N for Salix arctica (Arctic willow), we characterized soil, root, stem, and leaf (15) N natural abundance across 24 diapir and non-diapir frost boils in a High Arctic granitic semi-desert. When diapir horizons were available, S. arctica increased its subsurface (i.e., diapir) N uptake and plant root biomass doubled within diapir. Plant uptake of enriched (15) N injected into organic rich soil patches was 2.5-fold greater in diapir than in non-diapir frost boils. S. arctica percent cover was often higher (7.3 ± 1.0 [mean ± SE]) on diapiric frost boils, compared to frost boils without diapirs (4.4 ± 0.7), potentially reflecting the additional 20% nitrogen available in the subsurface of diapiric frost boils. Selective N acquisition from diapirs is a mechanism by which soil moisture indirectly enhances plant growth. Our work suggests that diapirs may be one mechanism contributing to Arctic greening by shrub expansion. © 2017 by the Ecological Society of America.

  3. Modeled diversity effects on microbial ecosystem functions of primary production, nutrient uptake, and remineralization.

    PubMed

    Goebel, Nicole L; Edwards, Christopher A; Follows, Michael J; Zehr, Jonathan P

    2014-01-01

    Ecosystem-wide primary productivity generally increases with primary producer diversity, emphasizing the importance of diversity for ecosystem function. However, most studies that demonstrate this positive relationship have focused on terrestrial and aquatic benthic systems, with little attention to the diverse marine pelagic primary producers that play an important role in regulating global climate. Here we show how phytoplankton biodiversity enhances overall marine ecosystem primary productivity and other ecosystem functions using a self-organizing ecosystem model. Diversity manipulation numerical experiments reveal positive, asymptotically saturating relationships between ecosystem-wide phytoplankton diversity and functions of productivity, nutrient uptake, remineralization, and diversity metrics used to identify mechanisms shaping these relationships. Increase in productivity with increasing diversity improves modeled ecosystem stability and model robustness and leads to productivity rates that exceed expected yields primarily through niche complementarity and facilitative interactions between coexisting phytoplankton types; the composition of traits in assemblages determines the magnitude of complementarity and selection effects. While findings based on these aggregate measures of diversity effects parallel those from the majority of experimental outcomes of terrestrial and benthic biodiversity-ecosystem function studies, we combine analyses of community diversity effects and investigations of the underlying interactions among phytoplankton types to demonstrate how an increase in recycled production of non-diatoms through an increase in new production of diatoms drives this diversity-cosystem function response. We demonstrate the important role that facilitation plays in the modeled marine plankton and how this facilitative interaction could amplify future climate-driven changes in ocean ecosystem productivity.

  4. Long-term effects of sustained beef feedlot manure application on soil nutrients, corn silage yield, and nutrient uptake.

    PubMed

    Ferguson, Richard B; Nienaber, John A; Eigenberg, Roger A; Woodbury, Brian L

    2005-01-01

    A field study was initiated in 1992 to investigate the long-term impacts of beef feedlot manure application (composted and uncomposted) on nutrient accumulation and movement in soil, corn silage yield, and nutrient uptake. Two application strategies were compared: providing the annual crop nitrogen (N) requirement (N-based rate) or crop phosphorus (P) removal (P-based rate), as well as a comparison to inorganic fertilizer. Additionally, effects of a winter cover crop were evaluated. Irrigated corn (Zea mays L.) was produced annually from 1993 through 2002. Average silage yield and crop nutrient removal were highest with N-based manure treatments, intermediate with P-based manure treatments, and least with inorganic N fertilizer. Use of a winter cover crop resulted in silage yield reductions in four of ten years, most likely due to soil moisture depletion in the spring by the cover crop. However, the cover crop did significantly reduce NO3-N accumulation in the shallow vadose zone, particularly in latter years of the study. The composted manure N-based treatment resulted in significantly greater soil profile NO3-N concentration and higher soil P concentration near the soil surface. The accounting procedure used to calculate N-based treatment application rates resulted in acceptable soil profile NO3-N concentrations over the short term. While repeated annual manure application to supply the total crop N requirement may be acceptable for this soil for several years, sustained application over many years carries the risk of unacceptable soil P concentrations.

  5. Unimodal size scaling of phytoplankton growth and the size dependence of nutrient uptake and use.

    PubMed

    Marañón, Emilio; Cermeño, Pedro; López-Sandoval, Daffne C; Rodríguez-Ramos, Tamara; Sobrino, Cristina; Huete-Ortega, María; Blanco, José María; Rodríguez, Jaime

    2013-03-01

    Phytoplankton size structure is key for the ecology and biogeochemistry of pelagic ecosystems, but the relationship between cell size and maximum growth rate (μ(max) ) is not yet well understood. We used cultures of 22 species of marine phytoplankton from five phyla, ranging from 0.1 to 10(6) μm(3) in cell volume (V(cell) ), to determine experimentally the size dependence of growth, metabolic rate, elemental stoichiometry and nutrient uptake. We show that both μ(max) and carbon-specific photosynthesis peak at intermediate cell sizes. Maximum nitrogen uptake rate (V(maxN) ) scales isometrically with V(cell) , whereas nitrogen minimum quota scales as V(cell) (0.84) . Large cells thus possess high ability to take up nitrogen, relative to their requirements, and large storage capacity, but their growth is limited by the conversion of nutrients into biomass. Small species show similar volume-specific V(maxN) compared to their larger counterparts, but have higher nitrogen requirements. We suggest that the unimodal size scaling of phytoplankton growth arises from taxon-independent, size-related constraints in nutrient uptake, requirement and assimilation. © 2012 Blackwell Publishing Ltd/CNRS.

  6. Interactive effects of phosphorus and Pseudomonas putida on chickpea (Cicer arietinum L.) growth, nutrient uptake, antioxidant enzymes and organic acids exudation.

    PubMed

    Israr, Dania; Mustafa, Ghulam; Khan, Khalid Saifullah; Shahzad, Muhammad; Ahmad, Niaz; Masood, Sajid

    2016-11-01

    Phosphorus (P) availability in alkaline soils of arid and semi-arid regions is a major constraint for decreased crop productivity. Use of plant growth promoting rhizobacteria (PGPR) may enhance plant growth through the increased plant antioxidation activity. Additionally, PGPR may increase nutrient uptake by plants as a result of induced root exudation and rhizosphere acidification. The current study was aimed to investigate combined effects of P and Pesudomonas putida (PGPR) on chickpea growth with reference to antioxidative enzymatic activity and root exudation mediated plant nutrient uptake, particularly P. Half of the seeds were soaked in PGPR solution, whereas others in sterile water and latter sown in soils. Plants were harvested 8 weeks after onset of experiment and analyzed for leaf nutrient contents, antioxidant enzymes activities and organic acids concentrations. Without PGPR, P application (+P) increased various plant growth attributes, plant uptake of P and Ca, soil pH, citric acid and oxalic acid concentrations, whereas decreased the leaf POD enzymatic activity as compared to the P-deficiency. PGPR supply both under -P and +P improved the plant growth, plant uptake of N, P, and K, antioxidative activity of SOD and POD enzymes and concentrations of organic acids, whereas reduced the rhizosphere soil pH. Growth enhancement by PGPR supply was related to higher plant antioxidation activity as well as nutrient uptake of chickpea including P as a result of root exudation mediated rhizosphere acidification.

  7. Complementary nutrient effects of separately collected human faeces and urine on the yield and nutrient uptake of spinach (Spinacia oleracea).

    PubMed

    Kutu, Funso R; Muchaonyerwa, Pardon; Mnkeni, Pearson N S

    2011-05-01

    A glasshouse experiment was conducted to evaluate the combined use of separately collected human faeces and urine as fertilizer for spinach (Spinacia oleracea) production. Seven human faeces N : urine N combinations (1 : 7 to 7 : 1) each supplying 200 kg N ha(-1) were evaluated along with sole human faeces, sole urine, inorganic fertilizer and an unamended control. Complementary application of the two resources, human faeces and urine, increased fresh and dry matter yields only in treatments having high proportions of urine. Nitrogen uptake followed the same trend but the opposite trend occurred for P uptake indicating that urine was a better source of N whereas human faeces were the better source of P. Potassium uptake was not influenced by the two resources. The minimal improvement observed in the fertilizer value of human faeces when co-applied with urine suggested that co-application of the two resources may not give an added yield advantage when compared with sole human faeces.

  8. Nutrient Content of Lettuce and its Improvement

    USDA-ARS?s Scientific Manuscript database

    Lettuce is a popular leafy vegetable and plays an important role in American diet and nutrition. Crisphead lettuce has much lower nutrient content than leaf and romaine types. As the synthesis or absorption of many nutrients is light dependent, the lower nutritional value of crisphead lettuce is due...

  9. Correlation of Emulsion Structure with Cellular Uptake Behavior of Encapsulated Bioactive Nutrients: Influence of Droplet Size and Interfacial Structure.

    PubMed

    Lu, Wei; Kelly, Alan L; Maguire, Pierce; Zhang, Hongzhou; Stanton, Catherine; Miao, Song

    2016-11-16

    In this study, an in vitro Caco-2 cell culture assay was employed to evaluate the correlation between emulsion structure and cellular uptake of encapsulated β-carotene. After 4 h of incubation, an emulsion stabilized with whey protein isolate showed the highest intracellular accumulation of β-carotene (1.06 μg), followed by that stabilized with sodium caseinate (0.60 μg) and Tween 80 (0.20 μg), which are 13-, 7.5-, and 2.5-fold higher than that of free β-carotene (0.08 μg), respectively. Emulsions with small droplet size (239 ± 5 nm) showed a higher cellular uptake of β-carotene (1.56 μg) than emulsiond with large droplet size (489 ± 9 nm) (0.93 μg) (p < 0.01). The results suggested that delivery in an emulsion significantly improved the cellular uptake of β-carotene and thus potentially its bioavailability; uptake was closely correlated with the interfacial composition and droplet size of emulsions. The findings support the potential for achieving optimal controlled and targeted delivery of bioactive nutrients by structuring emulsions.

  10. Nonrecirculating Hydroponic System Suitable for Uptake Studies at Very Low Nutrient Concentrations 1

    PubMed Central

    Gutschick, Vincent P.; Kay, Lou Ellen

    1991-01-01

    We describe the mechanical, electronic, hydraulic, and structural design of a nonrecirculating hydroponic system. The system is particularly suited to studies at very low nutrient concentrations, for which on-line concentration monitoring methods either do not exist or are costly and limited to monitoring relatively few individual plants. Solutions are mixed automatically to chosen concentrations, which can be set differently for every pump fed from a master supply of deionized water and nutrient concentrates. Pumping rates can be varied over a 50-fold range, up to 400 liters per day, which suffices to maintain a number of large, post-seedling plants in rapid growth at (sub)micromolar levels of N and P. The outflow of each pump is divided among as many as 12 separate root chambers. In each chamber one may monitor uptake by individual plant roots or segments thereof, by measuring nutrient depletion in batch samples of solution. The system is constructed from nontoxic materials that do not adsorb nutrient ions; no transient shifts of nitrate and phosphate concentrations are observable at the submicromolar level. Nonrecirculation of solutions limits problems of pH shifts, microbial contamination, and cumulative imbalances in unmonitored nutrients. We note several disadvantages, principally related to high consumption of deionized water and solutes. The reciprocating pumps can be constructed inexpensively, particularly by the researcher. We also report previously unattainable control of passive temperature rise of chambers exposed to full sunlight, by use of white epoxy paint. PMID:16668100

  11. Uptake and utilization of nutrients by developing kernels of Zea mays L

    SciTech Connect

    Lyznik, L.A.

    1987-01-01

    The mechanisms involved in amino acid and sugar uptake by developing maize kernels were investigated. In the pedicel region of maize kernel, the site of nutrient unloading from phloem terminals, amino acids are accumulated in considerable amounts and undergo significant interconversion. A wide spectrum of enzymatic activities involved in the metabolism of amino acids is observed in these tissues. Subsequently, amino acids are taken up by the endosperm tissue in processes which require energy and the presence of carrier proteins. Conversely, no evidence was found that energy and carriers are involved in sugar uptake. This process of sugar uptake is not inhibited by metabolic inhibitors and shows nonsaturable kinetics, but the uptake is pH-dependent. L-glucose is taken up at a significantly reduced rate in comparison to D-glucose uptake. Based on analysis of radioactivity distribution among sugar fractions after incubations of kernels with radiolabeled D-glucose, it seems that sucrose is not efficiently resynthesized from D-glucose in the endosperm tissue. Thus, the proposed mechanism of sucrose transport involving sucrose hydrolysis in the pedicel region and subsequent resynthesis in endosperm cells may not be the main pathway. The evidence that transfer cells play an active role in D-glucose transport is presented.

  12. The Thermodynamic Flow-Force Interpretation of Root Nutrient Uptake Kinetics: A Powerful Formalism for Agronomic and Phytoplanktonic Models.

    PubMed

    Le Deunff, Erwan; Tournier, Pierre-Henri; Malagoli, Philippe

    2016-01-01

    The ion influx isotherms obtained by measuring unidirectional influx across root membranes with radioactive or stable tracers are mostly interpreted by enzyme-substrate-like modeling. However, recent analyses from ion transporter mutants clearly demonstrate the inadequacy of the conventional interpretation of ion isotherms. Many genetically distinct carriers are involved in the root catalytic function. Parameters Vmax and Km deduced from this interpretation cannot therefore be regarded as microscopic parameters of a single transporter, but are instead macroscopic parameters (V[Formula: see text] and K[Formula: see text], apparent maximum velocity and affinity constant) that depend on weighted activities of multiple transporters along the root. The flow-force interpretation based on the thermodynamic principle of irreversible processes is an alternative macroscopic modeling approach for ion influx isotherms in which macroscopic parameters Lj (overall conductance of the root system for the substrate j) and πj (thermodynamic parameter when Jj = 0) have a straightforward meaning with respect to the biological sample studied. They characterize the efficiency of the entire root catalytic structure without deducing molecular characteristics. Here we present the basic principles of this theory and how its use can be tested and improved by changing root pre- and post-wash procedures before influx measurements in order to come as close as possible to equilibrium conditions. In addition, the constant values of Vm and Km in the Michaelis-Menten (MM) formalism of enzyme-substrate interpretation do not reflect variations in response to temperature, nutrient status or nutrient regimes. The linear formalism of the flow-force approach, which integrates temperature effect on nutrient uptake, could usefully replace MM formalism in the 1-3-dimension models of plants and phytoplankton. This formalism offers a simplification of parametrization to help find more realistic analytical

  13. The Thermodynamic Flow-Force Interpretation of Root Nutrient Uptake Kinetics: A Powerful Formalism for Agronomic and Phytoplanktonic Models

    PubMed Central

    Le Deunff, Erwan; Tournier, Pierre-Henri; Malagoli, Philippe

    2016-01-01

    The ion influx isotherms obtained by measuring unidirectional influx across root membranes with radioactive or stable tracers are mostly interpreted by enzyme-substrate-like modeling. However, recent analyses from ion transporter mutants clearly demonstrate the inadequacy of the conventional interpretation of ion isotherms. Many genetically distinct carriers are involved in the root catalytic function. Parameters Vmax and Km deduced from this interpretation cannot therefore be regarded as microscopic parameters of a single transporter, but are instead macroscopic parameters (Vmapp and Kmapp, apparent maximum velocity and affinity constant) that depend on weighted activities of multiple transporters along the root. The flow-force interpretation based on the thermodynamic principle of irreversible processes is an alternative macroscopic modeling approach for ion influx isotherms in which macroscopic parameters Lj (overall conductance of the root system for the substrate j) and πj (thermodynamic parameter when Jj = 0) have a straightforward meaning with respect to the biological sample studied. They characterize the efficiency of the entire root catalytic structure without deducing molecular characteristics. Here we present the basic principles of this theory and how its use can be tested and improved by changing root pre- and post-wash procedures before influx measurements in order to come as close as possible to equilibrium conditions. In addition, the constant values of Vm and Km in the Michaelis-Menten (MM) formalism of enzyme-substrate interpretation do not reflect variations in response to temperature, nutrient status or nutrient regimes. The linear formalism of the flow-force approach, which integrates temperature effect on nutrient uptake, could usefully replace MM formalism in the 1-3-dimension models of plants and phytoplankton. This formalism offers a simplification of parametrization to help find more realistic analytical expressions and numerical

  14. Transpiration, potassium uptake and flow in tobacco as affected by nitrogen forms and nutrient levels.

    PubMed

    Lu, Y X; Li, C J; Zhang, F S

    2005-05-01

    Ammonium can result in toxicity symptoms in many plants when it is supplied as the sole source of N. In this work, influences of different nitrogen forms at two levels (2 and 15 mm N) on growth, water relations and uptake and flow of potassium were studied in plants of Nicotiana tabacum 'K 326'. Xylem sap from different leaves was collected from 106-d-old tobacco plants cultured in quartz sand by application of pressure to the root system. Whole-shoot transpiration for each of the treatments was measured on a daily basis by weight determination. Total replacement of NO(3)(-)N by NH(4)(+)-N caused a substantial decrease in dry weight gain, even when plants grew under nutrient deficiency. Increasing nutrient concentration resulted in a greater net dry weight gain when nitrogen was supplied as NO(3)(-) or NH(4)NO(3), but resulted in little change when nitrogen was supplied as NH(4)(+). NH(4)(+)-N as the sole N-source also caused reduction in transpiration rate, changes in plant WUE (which depended on the nutrient levels) and a decrease in potassium uptake. However, the amount of xylem-transported potassium in the plants fed with NH(4)(+) was not reduced: it was 457 % or 596 % of the potassium currently taken up at low or high nutrient level, respectively, indicating a massive export from leaves and cycling of potassium in the phloem. Ammonium reduces leaf stomatal conductance of tobacco plants. The flow and partitioning of potassium in tobacco plants can be changed, depending on the nitrogen forms and nutrient levels.

  15. Changes in Growth and Nutrient Uptake in Brassica oleracea Exposed to Atmospheric Ammonia

    PubMed Central

    CASTRO, ANA; STULEN, INEKE; POSTHUMUS, FREEK S.; DE KOK, LUIT J.

    2006-01-01

    • Background and Aims Plant shoots form a sink for NH3, and are able to utilize it as a source of N. NH3 was used as a tool to investigate the interaction between foliar N uptake and root N uptake. To what extent NH3 can contribute to the N budget of the plant or can be regarded as a toxin, was investigated in relation to its concentration and the N supply in the root environment. • Methods Brassica oleracea was exposed to 0, 4 and 8 µL L−1 NH3, with and without nitrate in the nutrient solution. Growth, N compounds, nitrate uptake rate, soluble sugars and cations were measured. • Key Results In nitrate-sufficient plants, biomass production was not affected at 4 µL L−1 NH3, but was reduced at 8 µL L−1 NH3. In nitrate-deprived plants, shoot biomass was increased at both concentrations, but root biomass decreased at 8 µL L−1 NH3. The measured nitrate uptake rates agreed well with the plant's N requirement for growth. In nitrate-sufficient plants nitrate uptake at 4 and 8 µL L−1 NH3 was reduced by 50 and 66 %, respectively. • Conclusions The present data do not support the hypothesis that NH3 toxicity is caused by a shortage of sugars or a lack of capacity to detoxify NH3. It is unlikely that amino acids, translocated from the shoot to root, are the signal metabolites involved in the down-regulation of nitrate uptake, since no relationship was found between changes in nitrate uptake and root soluble N content of NH3-exposed plants. PMID:16291782

  16. A novel nanoparticle approach for imaging nutrient uptake by soil bacteria

    NASA Astrophysics Data System (ADS)

    O'Brien, S. L.; Whiteside, M. D.; Sholto-Douglas, D.; Antonopoulos, D. A.; Boyanov, M.; Durall, D. M.; Jones, M. D.; Lai, B.; O'Loughlin, E. J.; Kemner, K. M.

    2014-12-01

    The metabolic activities of soil microbes are the primary drivers of biogeochemical processes controlling the terrestrial carbon cycle, nutrient availability to plants, contaminant remediation, water quality, and other ecosystem services. However, we have a limited understanding of microbial metabolic processes such as nutrient uptake rates, substrate preferences, or how microbes and microbial metabolism are distributed throughout their habitat. Here we use a novel imaging technique with quantum dots (QDs, engineered semiconductor nanoparticles that produce size or composition-dependent fluorescence) to measure bacterial uptake of substrates of varying complexity. Cultures of two organisms differing in cell wall structure — Bacillus subtilis and Pseudomonas fluorescens — were grown in one of four ecologically relevant experimental conditions: nitrogen (N) limitation, phosphorus (P) limitation, N and P limitation, or no nutrient limitation. The cultures were then exposed to QDs with and without organic nutrients attached. X-ray fluorescence imaging was performed at 2ID-D at the Advanced Photon Source (APS) to determine the elemental distributions within both planktonic and surface-adhered (i.e, biofilms) cells. Uptake of unconjugated QDs was neglibible, and QDs conjugated to organic substrates varied depending on growth conditions and substrate, suggesting that they are a useful indicator of bacterial ecology. Cellular uptake was similar for the two bacterial species (2212 ± 273 nanoparticles per cm3 of cell volume for B. subtilis and 1682 ± 264 for P. fluorescens). On average, QD assimilation was six times greater when N or P was limiting, and cells took up about twice as much phosphoserine compared to other substrates, likely because it was the only compound providing both N and P. These results showed that regardless of their cell wall structure, bacteria can selectively take up quantifiable levels of QDs based on substrate and environmental conditions. APS

  17. Polyethylene mulch stimulates early root growth and nutrient uptake of transplanted tomatoes

    SciTech Connect

    Wien, H.C.; Minotti, P.L.; Grubinger, V.P. . Dept. of Fruit and Vegetable Science)

    1993-03-01

    Tomato (Lycopersicon esculentum Mill.) plants grown on polyethylene (PE) mulch in New York State frequently have more branches and increased mineral nutrient uptake and yield than plants not mulched. In four field experiments conducted on a silt loam soil, clear PE mulch stimulated root extension shortly after transplanting. One week after transplanting, roots were significantly longer for mulched than for unmulched plants in all four experiments, whereas above ground dry matter differences did not become significant until 14 days after transplanting in two of four trials. Mulching increased branching, hastened flowering on basal branches, and increased concentration of major nutrients in the above ground parts. In the field, stimulation of above ground growth due to mulch might be brought about by warming of the stem by air escaping from the planting hole in the mulch. However, an experiment with black, white, or clear mulch, in which the planting hole was either left uncovered or covered with soil, showed no effect of hole closure on branching even though air temperature near the stem was increased when holes were left uncovered. The results taken together imply that the increased above ground growth observed with mulching is a consequence of enhanced root growth and nutrient uptake.

  18. Influence of sodium selenite on growth, nutrient utilization and selenium uptake in Cavia porcellus.

    PubMed

    Mahima; Garg, A K; Mudgal, Vishal

    2012-05-01

    A 70 day experiment on forty guinea pigs (Cavia porcellus) was conducted to find the influence of different level of sodium selenite (inorganic selenium supplementation) on growth, nutrient utilization and selenium uptake. The sodium selenite was supplemented into a basal diet at 0, 0.1, 0.2 and 0.3 ppm, respectively and the basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), ascorbic acid (200 mg kg) and 0.1 ppm Se to meet their nutrient requirements. Daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber and nitrogen-free extract as well as uptake of calcium and phosphorus, total body weight and average daily gain were similar (p>0.05) among the four groups. However, there was a trend of increase in Se absorption of the guinea pigs with the increasing levels of Se, in the groups given 0.2 and 0.3 ppm of Se. It can be concluded that requirement of Se in guinea pigs is 0.1 ppm, as supplementation of > or =0.1 ppm sodium selenite in the diet (having 0.1 ppm Se) did not enhanced their growth rate and nutrient utilization.

  19. Intestinal nutrient uptake measurements and tissue damage: validating the everted sleeves method.

    PubMed

    Starck, J M; Karasov, W H; Afik, D

    2000-01-01

    The reliability of methods for nutrient uptake measurements across the intestinal epithelium relies on the integrity of the mucosal epithelium and the enterocytes. We tested effects of tissue handling during the "everted sleeves method" on the length of intestinal villi, the surface magnification, the circumference of the gut, and the thickness of the muscle layer in sunbirds (Nectarinia osea), chicken (Gallus gallus), and mice (Mus domesticus). The sunbird has thin and delicate intestinal villi that are greatly affected by the everted sleeves method. After eversion and incubation, villi lost 30% of their original length. The severe tissue damage coincides with uptake measurements for glucose that were an order of magnitude lower than in other nectar-feeding (nectarivorous) birds of similar body size. Tissue handling during the everted sleeves method had significant effects on morphometric parameters of chicken and mouse intestines, but on a light-microscopical level, the tissue integrity and the cytology of the enterocytes were not altered. Therefore, we think that the everted sleeves method renders reliable and reproducible measurements of nutrient uptake in those species. We conclude that a histological evaluation is necessary to assess the reliability of the method before it is applied to adults or to the developmental stage of any species.

  20. Colonisation of a Zn, Cd and Pb hyperaccumulator Thlaspi praecox Wulfen with indigenous arbuscular mycorrhizal fungal mixture induces changes in heavy metal and nutrient uptake.

    PubMed

    Vogel-Mikus, Katarina; Pongrac, Paula; Kump, Peter; Necemer, Marijan; Regvar, Marjana

    2006-01-01

    Plants of the Zn, Cd and Pb hyperaccumulator Thlaspi praecox Wulfen (Brassicaceae) inoculated or not with indigenous arbuscular mycorrhizal (AM) fungal mixture were grown in a highly Cd, Zn and Pb contaminated substrate in order to evaluate the functionality of symbiosis and assess the possible impact of AM colonisation on heavy metal uptake and tolerance. The results suggest AM development in the metal hyperaccumulating T. praecox is favoured at elevated nutrient demands, e.g. during the reproductive period. AM colonisation parameters positively correlated with total soil Cd and Pb. Colonised plants showed significantly improved nutrient and a decreased Cd and Zn uptake as revealed by TRXRF, thus confirming the functionality of the symbiosis. Reduced heavy metal uptake, especially at higher soil metal contents, indicates a changed metal tolerance strategy in colonised T. praecox plants. This is to our knowledge the first report on AM colonisation of the Zn, Cd and Pb hyperaccumulator T. praecox in a greenhouse experiment.

  1. Cation Uptake and Allocation by Red Pine Seedlings under Cation-Nutrient Stress in a Column Growth Experiment

    SciTech Connect

    Shi, Zhenqing; Balogh-Brunstad, Zsuzsanna; Grant, Michael R.; Harsh, James B.; Gill, Richard; Thomashow, Linda; Dohnalkova, Alice; Stacks, Daryl; Letourneau, Melissa; Keller, Chester K.

    2014-01-10

    Background and Aims Plant nutrient uptake is affected by environmental stress, but how plants respond to cation-nutrient stress is poorly understood. We assessed the impact of varying degrees of cation-nutrient limitation on cation uptake in an experimental plant-mineral system. Methods Column experiments, with red pine (Pinus resinosa Ait.) seedlings growing in sand/mineral mixtures, were conducted for up to nine months under a range of Ca- and K-limited conditions. The Ca and K were supplied from both minerals and nutrient solutions with varying Ca and K concentrations. Results Cation nutrient stress had little impact on carbon allocation after nine months of plant growth and K was the limiting nutrient for biomass production. The Ca/Sr and K/Rb ratio results allowed independent estimation of dissolution incongruency and discrimination against Sr and Rb during cation uptake processes. The fraction of K in biomass from biotite increased with decreasing K supply from nutrient solutions. The mineral anorthite was consistently the major source of Ca, regardless of nutrient treatment. Conclusions Red pine seedlings exploited more mineral K in response to more severe K deficiency. This did not occur for Ca. Plant discrimination factors must be carefully considered to accurately identify nutrient sources using cation tracers.

  2. Vegetation study to assess the nutrient uptake potential of emergent macrophytes in semi-arid wetlands

    NASA Astrophysics Data System (ADS)

    Adhikari, A. R.; Acharya, K.; Yu, Z.

    2011-12-01

    Arc GIS software and ground verification was used to map vegetation of a downstream riparian wetland in the Las Vegas Wash. Monogeneric stands of Phragmites australis dominated the spatial distribution of emergent macrophytes. This paper aims to evaluate the aboveground biomass production and nutrients (total nitrogen and total phosphorus) content to determine the maximum nutrient removal efficiency by harvesting Typha domingensis and P. australis during their highest growth rate, in a semi arid wetlands. The average aboveground biomass of T. domingensis (5.61to11.07 kg m-2) was significantly higher than P. australis (2.49-6.35 kg m-2) in the month of July 2010. Despite the high nutrient concentration measured in P. australis aboveground tissue, the net standing stock accumulation potential was still higher in T. domingensis. The net aboveground standing stock of nutrients in the Las Vegas Wash wetlands was measured (approximately 26418.7 kg N and 1264.1 kg P) for P. australis and (approximately 5183.8 kg N and 272.83 kg P) for T. domingensis. Harvesting aboveground biomass from both species would remove total nitrogen significantly from the system but not total phosphorus. Furthermore, harvesting P. australis during the peak growth period might positively impact the semi arid wetlands because it will provide more ground for T. domingensis extension. The comparative analysis of the emergent vegetation potential for biomass accumulation, nutrient concentration and standing stock was not significantly different among humid and semi arid wetlands. The humid and semi arid wetlands are characterized by a better understanding of the long term function and processes associated with the nutrient uptake potential of wetlands vegetation.

  3. Approaches in the determination of plant nutrient uptake and distribution in space flight conditions

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, M.

    2000-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  4. Approaches in the Determination of Plant Nutrient Uptake and Distribution in Space Flight Conditions

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, Mark

    1998-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which may impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the nuclides Ca45 and Fe59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  5. Approaches in the determination of plant nutrient uptake and distribution in space flight conditions

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, M.

    2000-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  6. Approaches in the Determination of Plant Nutrient Uptake and Distribution in Space Flight Conditions

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, Mark

    1998-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which may impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the nuclides Ca45 and Fe59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  7. Approaches in the determination of plant nutrient uptake and distribution in space flight conditions.

    PubMed

    Heyenga, A G; Forsman, A; Stodieck, L S; Hoehn, A; Kliss, M

    2000-01-01

    The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

  8. Nematodes enhance plant growth and nutrient uptake under C and N-rich conditions

    PubMed Central

    Gebremikael, Mesfin T.; Steel, Hanne; Buchan, David; Bert, Wim; De Neve, Stefaan

    2016-01-01

    The role of soil fauna in crucial ecosystem services such as nutrient cycling remains poorly quantified, mainly because of the overly reductionistic approach adopted in most experimental studies. Given that increasing nitrogen inputs in various ecosystems influence the structure and functioning of soil microbes and the activity of fauna, we aimed to quantify the role of the entire soil nematode community in nutrient mineralization in an experimental set-up emulating nutrient-rich field conditions and accounting for crucial interactions amongst the soil microbial communities and plants. To this end, we reconstructed a complex soil foodweb in mesocosms that comprised largely undisturbed native microflora and the entire nematode community added into defaunated soil, planted with Lolium perenne as a model plant, and amended with fresh grass-clover residues. We determined N and P availability and plant uptake, plant biomass and abundance and structure of the microbial and nematode communities during a three-month incubation. The presence of nematodes significantly increased plant biomass production (+9%), net N (+25%) and net P (+23%) availability compared to their absence, demonstrating that nematodes link below- and above-ground processes, primarily through increasing nutrient availability. The experimental set-up presented allows to realistically quantify the crucial ecosystem services provided by the soil biota. PMID:27605154

  9. Nematodes enhance plant growth and nutrient uptake under C and N-rich conditions

    NASA Astrophysics Data System (ADS)

    Gebremikael, Mesfin T.; Steel, Hanne; Buchan, David; Bert, Wim; de Neve, Stefaan

    2016-09-01

    The role of soil fauna in crucial ecosystem services such as nutrient cycling remains poorly quantified, mainly because of the overly reductionistic approach adopted in most experimental studies. Given that increasing nitrogen inputs in various ecosystems influence the structure and functioning of soil microbes and the activity of fauna, we aimed to quantify the role of the entire soil nematode community in nutrient mineralization in an experimental set-up emulating nutrient-rich field conditions and accounting for crucial interactions amongst the soil microbial communities and plants. To this end, we reconstructed a complex soil foodweb in mesocosms that comprised largely undisturbed native microflora and the entire nematode community added into defaunated soil, planted with Lolium perenne as a model plant, and amended with fresh grass-clover residues. We determined N and P availability and plant uptake, plant biomass and abundance and structure of the microbial and nematode communities during a three-month incubation. The presence of nematodes significantly increased plant biomass production (+9%), net N (+25%) and net P (+23%) availability compared to their absence, demonstrating that nematodes link below- and above-ground processes, primarily through increasing nutrient availability. The experimental set-up presented allows to realistically quantify the crucial ecosystem services provided by the soil biota.

  10. Improving PMTCT Uptake in Rural South Africa

    PubMed Central

    Weiss, S. M.; Peltzer, K.; Villar-Loubet, O.; Shikwane, M. E.; Cook, R.; Jones, D. L.

    2016-01-01

    Introduction Despite the widespread availability of prevention of mother-to-child transmission (PMTCT) programs, many women in sub-Saharan Africa do not participate in PMTCT. This pilot study aimed to utilize partner participation in an intervention to support PMTCT uptake. Methods Couples (n = 239) were randomized to receive either a comprehensive couples-based PMTCT intervention or the standard of care. Results Compared to the standard of care, participants receiving the intervention increased HIV- and PMTCT-related knowledge (F1,474 = 13.94, p = .004) and uptake of PMTCT, as defined by infant medication dosing (74% vs. 46%, χ2 = 4.69, p = .03). Discussion Results indicate that increasing male attendance at antenatal clinic visits may be “necessary but not sufficient” to increase PMTCT uptake. Increasing HIV knowledge of both partners and encouraging active male participation in the PMTCT process through psychoeducational interventions may be a strategy to increase the uptake of PMTCT in South Africa. PMID:23778240

  11. Uptake of Pharmaceuticals Influences Plant Development and Affects Nutrient and Hormone Homeostases.

    PubMed

    Carter, Laura J; Williams, Mike; Böttcher, Christine; Kookana, Rai S

    2015-10-20

    The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications.

  12. Plasticity in N uptake among sympatric species with contrasting nutrient acquisition strategies in a tropical forest.

    PubMed

    Andersen, Kelly M; Mayor, Jordan R; Turner, Benjamin L

    2017-03-06

    Nitrogen (N) availability influences the productivity and distribution of plants in tropical montane forests. Strategies to acquire soil N, such as direct uptake of organic compounds or associations with root symbionts to enhance N acquisition in exchange for carbon (C), may facilitate plant species coexistence and ecosystem N retention. Alternatively, rapid microbial turnover of soil N forms in tropical soils might promote flexible plant N-uptake strategies and mediate species coexistence. We tested whether sympatric plant species with divergent root symbiont associations, and therefore potentially different nutrient acquisition strategies, partition chemical forms of N or show plasticity in N uptake in a tropical pre-montane forest in Panama. We traced the movement of three (15) N forms into soil pools, microbes, and seedlings of eleven species differing in root traits. Seedlings were grown in a split-plot field transplant experiment, with plots receiving equimolar mixtures of ammonium, nitrate, and glycine, with one form isotopically labeled in each block. After 48-hours, more (15) N was recovered in microbes than in plants, while all pools (extractable organic and inorganic N, microbial biomass, and leaves) contained greater amounts of (15) N from nitrate than from ammonium or glycine. Furthermore, (13) C from dual-labeled glycine was not recovered in the leaves of any seedlings, suggesting the studied species do not directly take up organic N or transform organic N prior to translocation to leaves. Nitrogen uptake differed by root symbiont group only for nitrate, with greater (15) N recovery in plants with arbuscular mycorrhizal (AM) associations or proteoid roots compared to orchids. Some root trait groups differed in (15) N recovery among N forms, with greater nitrate uptake than ammonium or glycine by AM-associated and N2 -fixing plants. However, only five of eleven species showed differences in uptake among N forms. Our results indicate flexibility in

  13. Influence of the interaction between phosphate and arsenate on periphyton's growth and its nutrient uptake capacity.

    PubMed

    Rodriguez Castro, Ma Carolina; Urrea, Gemma; Guasch, Helena

    2015-01-15

    Periphyton communities grown in microcosms were studied under the exposure to different arsenate (As) and phosphate (P) regimes with the aim of revealing the effect of chronic exposure to As on periphyton physiological and structural characteristics. Also, we aimed to study periphyton changes on sensitivity to As, exposed to different P and As regimes. As affected structural and functional parameters of periphyton communities starved of P, inhibiting algal growth, photosynthetic capacity, changing community composition and reducing the ability of the community to retain P. The effects of As on these parameters were only detected in P starved communities, showing that chronic exposure to As led to changes in the photosynthetic apparatus under the conditions of P-limitation, but not when P-availability was higher. This fact reveals a lower toxicity and/or a higher adaptation of the P-amended community. Intracellular As contents were higher in communities starved of P. However, As tolerance was only induced by the combination of As and P but not by As or P alone indicating that tolerance induction may be an ATP-dependent mechanism. This study reveals that chronic exposure of natural communities to environmentally realistic As concentrations will damage periphyton communities affecting key ecosystem processes, as P uptake, leading to changes in stream ecosystems, as these organisms play a key role in nutrient cycling through nutrient uptake and transfer to higher trophic levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

    PubMed

    Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

    2017-01-01

    cultivation in the DeepFlow negatively compared to substrate-based propagation. Water-based propagation resulted in frequent transient discolorations after transplanting in all cultivation systems, indicating a factor, other than irrigation supply of water, nutrients, and oxygen, influencing plant uptake. Plant uptake rates for water, nutrients, and oxygen are offered as a more fundamental way to compare and improve growing systems.

  15. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems

    PubMed Central

    Blok, Chris; Jackson, Brian E.; Guo, Xianfeng; de Visser, Pieter H. B.; Marcelis, Leo F. M.

    2017-01-01

    cultivation in the DeepFlow negatively compared to substrate-based propagation. Water-based propagation resulted in frequent transient discolorations after transplanting in all cultivation systems, indicating a factor, other than irrigation supply of water, nutrients, and oxygen, influencing plant uptake. Plant uptake rates for water, nutrients, and oxygen are offered as a more fundamental way to compare and improve growing systems. PMID:28443129

  16. Quantifying nutrient uptake as driver of rock weathering in forest ecosystems by magnesium stable isotopes

    NASA Astrophysics Data System (ADS)

    Uhlig, David; Schuessler, Jan A.; Bouchez, Julien; Dixon, Jean L.; von Blanckenburg, Friedhelm

    2017-04-01

    Plants and soil microbiota play an active role in rock weathering and potentially couple weathering at depth with erosion at the soil surface. The nature of this coupling is still unresolved because we lacked means to quantify the passage of chemical elements from rock through higher plants. In a temperate forested landscape of the Southern Sierra Critical Zone Observatory (SSCZO), California, we measured magnesium (Mg) stable isotopes that are sensitive indicators of Mg utilisation by biota. We find that Mg is highly bio-utilised: 50-100 % of the Mg released by chemical weathering is taken up by forest trees. To estimate the tree uptake of other bio-utilised elements (K, Ca, P and Si) we compared the dissolved fluxes of these elements and Mg in rivers with their solubilisation fluxes from rock (rock dissolution flux minus secondary mineral formation flux). We find a deficit in the dissolved fluxes throughout, that we attribute to the nutrient uptake by forest trees. Therefore, both the Mg isotopes and the flux comparison suggests that a substantial part of the major element weathering flux is consumed by the tree biomass. This isotopic and elemental compartment separation is preserved only if the mineral nutrients contained in biomass are prevented from re-dissolution after litter fall, showing that these nutrients have been removed as "solid" biomass. The enrichment of 26Mg over 24Mg in tree trunks relative to leaf litter suggests that this removal occurs mainly in coarse woody debris (CWD). Today, CWD is exported from the ecosystem by tree logging. Over pre-anthropogenic weathering time scales, a similar removal flux might have been in operation in the form of natural erosion of CWD. Regardless of the removal mechanism, our data provides the first direct quantification of biogenic uptake following weathering. We find that Mg and other bio-elements are taken up by trees at up to 7 m depth, and surface recycling of all bio-elements but P is minimal. Thus, in the

  17. Nutrient inputs via rock weathering point to enhanced CO2 uptake capacity of the terrestrial biosphere

    NASA Astrophysics Data System (ADS)

    Dass, P.; Houlton, B. Z.; Wang, Y.; Pak, B. C.; Morford, S.

    2016-12-01

    Empirical evidence of widespread scarcity of nitrogen (N) and phosphorus (P) availability in natural land ecosystems constrains the carbon dioxide (CO2) uptake capacity of the global biosphere. Recent studies have pointed to the importance of rock weathering in supplying both N and P to terrestrial soils and vegetation; however, the potential for N and P to rapidly weather from different rocks and thereby alter the global carbon (C) cycle remains an open question, particularly at the global scale. Here, we combine empirical measurements and a new global simulation model to quantify the flux of N and P released from rocks to the terrestrial biosphere. Our model considers the role of tectonic uplift and physical and chemical weathering on rock nutrient cycling by using a probabilistic approach that is anchored in watershed-scale 10Be and Na data from the world's rivers. We use USGS DEM data for relief, monthly averaged MODIS evapotranspiration data and global precipitation datasets. Based on simulations using mean climate data for the past 10 years, we estimate annual values of 11 Tg of N and 6 Tg of P to weather from rocks to the terrestrial biosphere. The rate of N weathering rivals that of atmospheric N deposition in natural ecosystems, and the P weathering flux is approximately 6 times higher than prior estimates based on a modeling approach where the chemical weathering is dependant on lithology and runoff with further factors correcting for soil shielding and temperature. The increase in nutrient inputs we simulate reveals an important role for rock weathering to support new production in terrestrial ecosystems, and thereby allow for additional CO2 uptake in sectors of the biosphere where weathering rates are substantial. Given that current generation of models are yet to consider how short-term weathering of rocks can affect nutrient limited C storage, these results will help to advance the geochemical aspects of carbon-climate feedback this century. Moreover

  18. Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse

    NASA Astrophysics Data System (ADS)

    den Haan, Joost; Huisman, Jef; Brocke, Hannah J.; Goehlich, Henry; Latijnhouwers, Kelly R. W.; van Heeringen, Seth; Honcoop, Saskia A. S.; Bleyenberg, Tanja E.; Schouten, Stefan; Cerli, Chiara; Hoitinga, Leo; Vermeij, Mark J. A.; Visser, Petra M.

    2016-06-01

    Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations (3-fold) in waters overlying a fringing reef at the island of Curaçao (Southern Caribbean). To understand how benthic reef organisms make use of such nutrient pulses, we determined ammonium, nitrate and phosphate uptake rates for one abundant coral species, turf algae, six macroalgal and two benthic cyanobacterial species in a series of laboratory experiments. Nutrient uptake rates differed among benthic functional groups. The filamentous macroalga Cladophora spp., turf algae and the benthic cyanobacterium Lyngbya majuscula had the highest uptake rates per unit biomass, whereas the coral Madracis mirabilis had the lowest. Combining nutrient uptake rates with the standing biomass of each functional group on the reef, we estimated that the ammonium and phosphate delivered during runoff events is mostly taken up by turf algae and the two macroalgae Lobophora variegata and Dictyota pulchella. Our results support the often proposed, but rarely tested, assumption that turf algae and opportunistic macroalgae primarily benefit from episodic inputs of nutrients to coral reefs.

  19. Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse

    PubMed Central

    den Haan, Joost; Huisman, Jef; Brocke, Hannah J.; Goehlich, Henry; Latijnhouwers, Kelly R. W.; van Heeringen, Seth; Honcoop, Saskia A. S.; Bleyenberg, Tanja E.; Schouten, Stefan; Cerli, Chiara; Hoitinga, Leo; Vermeij, Mark J. A.; Visser, Petra M.

    2016-01-01

    Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations (3-fold) in waters overlying a fringing reef at the island of Curaçao (Southern Caribbean). To understand how benthic reef organisms make use of such nutrient pulses, we determined ammonium, nitrate and phosphate uptake rates for one abundant coral species, turf algae, six macroalgal and two benthic cyanobacterial species in a series of laboratory experiments. Nutrient uptake rates differed among benthic functional groups. The filamentous macroalga Cladophora spp., turf algae and the benthic cyanobacterium Lyngbya majuscula had the highest uptake rates per unit biomass, whereas the coral Madracis mirabilis had the lowest. Combining nutrient uptake rates with the standing biomass of each functional group on the reef, we estimated that the ammonium and phosphate delivered during runoff events is mostly taken up by turf algae and the two macroalgae Lobophora variegata and Dictyota pulchella. Our results support the often proposed, but rarely tested, assumption that turf algae and opportunistic macroalgae primarily benefit from episodic inputs of nutrients to coral reefs. PMID:27353576

  20. Uptake, release, and absorption of nutrients into the marine environment by the green mussel (Perna viridis).

    PubMed

    Srisunont, Chayarat; Babel, Sandhya

    2015-08-15

    The nutrient uptake and release by the mussels in relation with amount of food consumption are emphasised in this research. Results of the study demonstrate that about 16% of the total mass dry weight food consumed by the mussels was released as faeces. The depositions of particulate carbon, nitrogen, and phosphorus in mussel faeces were found to be 26.3, 5.7, and 0.6mg/day/indv respectively. Soluble inorganic nutrients such as NH4(+)-N (2.5mg/day/indv), and PO4(3-)-P (0.6mg/day/indv) were also released as mussel excretion. The nutrient absorption efficiency for the green mussel body was found to be 65.1% for carbon, 62.1% for nitrogen, and 79.2% for phosphorus. Subsequently, green mussels can remove particulate carbon, nitrogen and phosphorus at 108.1, 13.5, and 4.6mg/day/indv from aquatic systems. Finally, the results can help in estimating the carrying capacity of mussel cultivation without deteriorating the water quality in marine ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Elemental uptake and distribution of nutrients in avocado mesocarp and the impact of soil quality.

    PubMed

    Reddy, Mageshni; Moodley, Roshila; Jonnalagadda, Sreekanth B

    2014-07-01

    The distribution of 14 elements (both essential and non-essential) in the Hass and Fuerte cultivars of avocados grown at six different sites in KwaZulu-Natal, South Africa, was investigated. Soils from the different sites were concurrently analysed for elemental concentration (both total and exchangeable), pH, organic matter and cation exchange capacity. In both varieties of the fruit, concentrations of the elements Cd, Co, Cr, Pb and Se were extremely low with the other elements being in decreasing order of Mg > Ca > Fe > Al > Zn > Mn > Cu > Ni > As. Nutritionally, avocados were found to be a good dietary source of the micronutrients Cu and Mn. In soil, Pb concentrations indicated enrichment (positive geoaccumuluation indices) but this did not influence uptake of the metal by the plant. Statistical analysis was done to evaluate the impact of soil quality parameters on the nutrient composition of the fruits. This analysis indicated the prevalence of complex metal interactions at the soil-plant interface that influenced their uptake by the plant. However, the plant invariably controlled metal uptake according to metabolic needs as evidenced by their accumulation and exclusion.

  2. Effects of Harvesting Intensity and Herbivory by White-tailed Deer on Vegetation and Nutrient Uptake in a Northern Hardwood Forest

    NASA Astrophysics Data System (ADS)

    Yorks, T. E.; Leopold, D. J.; Raynal, D. J.; Murdoch, P. S.; Burns, D. A.

    2003-12-01

    We quantified the response of vegetation and nutrient uptake in a northern hardwood forest in southeastern New York for three to four years after three intensities of harvesting: clearcutting, heavy timber stand improvement (TSI), light TSI (97, 29, and 10% basal area reductions, respectively). We also quantified effects of white-tailed deer (Odocoileus virginianus) herbivory on nutrient retention by vegetation. Total biomass and nutrient accumulation in vegetation was higher after TSI than clearcutting in the first two years but was highest in the fenced clearcut in subsequent years, indicating that TSI or partial harvesting is a viable management tool for harvesting timber while consistently maintaining high rates of nutrient retention. After clearcutting, biomass and nutrient retention were initially dominated by woody stems <1.4 m tall and herbaceous vegetation, but saplings 0.1-5.0 cm DBH became the most important contributors to biomass and nutrient accumulation within four years. However, after both intensities of TSI, trees >5.0 cm DBH continued to account for most biomass and nutrient accumulation whereas understory vegetation accumulated little biomass or nutrients. Heavy TSI resulted in increased regeneration of only two tree species (Acer pensylvanicum, Fagus grandifolia), but clearcutting allowed these two species, mature forest species (A. saccharum, Betula alleghaniensis), and the early successional Prunus pensylvanica to regenerate. Several early successional shrub and herbaceous species were also important to nutrient retention after clearcutting, including Polygonum cilinode, Rubus spp., and Sambucus racemosa. Herbivory by white-tailed deer dramatically reduced biomass and nutrient accumulation by woody stems <5 cm DBH after clearcutting (5.5 vs. 0.7 Mg biomass/ha and 30.4 vs. 6.3 kg N/ha on fenced and unfenced clearcut sites, respectively, after four years), indicating the important influence this herbivore can have on nutrient retention in

  3. Water uptake and nutrient concentrations under a floodplain oak savanna during a non-flood period, lower Cedar River, Iowa

    USGS Publications Warehouse

    Schilling, K.E.; Jacobson, P.

    2009-01-01

    Floodplains during non-flood periods are less well documented than when flooding occurs, but non-flood periods offer opportunities to investigate vegetation controls on water and nutrient cycling. In this study, we characterized water uptake and nutrient concentration patterns from 2005 to 2007 under an oak savanna located on the floodplain of the Cedar River in Muscatine County, Iowa. The water table ranged from 0.5 to 2.5 m below ground surface and fluctuated in response to stream stage, plant water demand and rainfall inputs. Applying the White method to diurnal water table fluctuations, daily ET from groundwater averaged more than 3.5 mm/day in June and July and approximately 2 mm/day in May and August. Total annual ET averaged 404 mm for a growing season from mid-May to mid-October. Savanna groundwater concentrations of nitrate-N, ammonium-N, and phosphate-P were very low (mean <0.18, <0.14, <0.08 mg/l, respectively), whereas DOC concentrations were high (7.1 mg/l). Low concentrations of N and P were in contrast to high nutrient concentrations in the nearby Cedar River, where N and P averaged 7.5 mg/ l and 0.13, respectively. In regions dominated by intensive agriculture, study results document valuable ecosystem services for native floodplain ecosystems in reducing watershed-scale nutrient losses and providing an oasis for biological complexity. Improved understanding of the environmental conditions of regionally significant habitats, including major controls on water table elevations and water quality, offers promise for better management aimed at preserving the ecology of these important habitats. Copyright ?? 2009 John Wiley & Sons, Ltd.

  4. Nutrient Uptake and Cycles of Change: the Ventura River in Southern California

    NASA Astrophysics Data System (ADS)

    Leydecker, A.; Simpson, J.; Grabowski, L.

    2003-12-01

    Watersheds in Mediterranean climates are characterized by extreme seasonal and inter-annual rainfall variability. This variability engenders cycles of sediment deposition and removal, algal growth, and the advance and retreat of riparian and aquatic vegetation. In turn, these changes dramatically alter the appearance and biological functioning of rivers and streams, regulating the uptake of nutrients. The Ventura River drains 580 sq. km of mountainous coastal watershed 100 km northwest of Los Angles, Ca. More than 90 % of the average annual rainfall of 500 mm falls between December and March with most of the annual runoff occurring within a few days. Since 1930, annual runoff has varied from 0.01 to 70 cm/ha, with a mean of 12 and median of 4 cm. We have been measuring dissolved nutrient concentrations at four locations on the lower 9 kilometers of the river for the past 3 years (annual runoff of 19, 0.6 and 14 cm, respectively) and quantifying the relative abundance of plants and algae during 2003. A subsequent decrease in nutrient concentrations below a treated sewage outfall at km 8 provides estimates of nutrient uptake under changing conditions. Nitrate concentrations on the river peak in early winter, presumably from mineralization and mobilization after the advent of the rainy season, and decrease to a minimum by late summer. Phosphate, controlled by dry-season treatment plant outflows, has an opposite pattern. The seasonal variation in both is considerable (0 to 380 microM for nitrate, 0 to 35 microM for phosphate). Major winter storms, such as occur during severe El Nino years (peak flows > 1000 cms), begin a transformational cycle by completely scouring the channel of vegetation and fine sediment; this occurs, on average, once every 10 to 12 years (the interval has varied from 3 to 30 years). The scoured channel, with warmer water temperatures, the absence of shade and a nutrient rich environment, becomes dominated by filamentous algae (principally

  5. Effect of organic selenium supplementation on growth, Se uptake, and nutrient utilization in guinea pigs.

    PubMed

    Chaudhary, Mahima; Garg, Anil Kumar; Mittal, Ganesh Kumar; Mudgal, Vishal

    2010-02-01

    Forty weaned male guinea pigs (Cavia porcellus) of 152.6 +/- 7.96 g mean body weight were divided into four equal groups and fed a common basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), and ascorbic acid at 200 mg/kg to meet their nutrient requirements along with 0, 0.1, 0.2, and 0.3 ppm of organic selenium (Se) in groups I, II, III, and IV, respectively. Experimental feeding lasted for a period of 10 weeks, during which, daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber, and nitrogen-free extract as well as uptake of calcium and phosphorus were similar (P > 0.05) among the four groups. Feed:gain ratio was also similar (P > 0.05) in the four groups. However, digestibility of crude protein was significantly (P < 0.001) higher in group II supplemented with 0.1 ppm organic Se as compared to other three group. Intake and absorption of Se was significantly (P < 0.001) higher in all the Se supplemented groups as compared to control group. Average daily gain (ADG) was significantly (P < 0.05) higher in group II (3.16 g/day) and III (3.38 g/day) as compared to group I (2.88 g/day). However, ADG in group IV (supplemented 0.3 ppm organic Se) was significantly (P < 0.05) lower (2.83 g/day) than group II and III, but comparable (P > 0.05) to group I. Findings of the present experiment suggests that Se requirements of guinea pigs are > or =0.2 ppm, as supplementation of 0.1 ppm organic Se in the diet (having 0.1 ppm Se) not only enhanced their growth rate but also improved the protein utilization.

  6. Toward a universal mass-momentum transfer relationship for predicting nutrient uptake and metabolite exchange in benthic reef communities

    NASA Astrophysics Data System (ADS)

    Falter, James L.; Lowe, Ryan J.; Zhang, Zhenlin

    2016-09-01

    Here we synthesize data from previous field and laboratory studies describing how rates of nutrient uptake and metabolite exchange (mass transfer) are related to form drag and bottom stresses (momentum transfer). Reanalysis of this data shows that rates of mass transfer are highly correlated (r2 ≥ 0.9) with the root of the bottom stress (τbot0.4) under both waves and currents and only slightly higher under waves (~10%). The amount of mass transfer that can occur per unit bottom stress (or form drag) is influenced by morphological features ranging anywhere from millimeters to meters in scale; however, surface-scale roughness (millimeters) appears to have little effect on actual nutrient uptake by living reef communities. Although field measurements of nutrient uptake by natural reef communities agree reasonably well with predictions based on existing mass-momentum transfer relationships, more work is needed to better constrain these relationships for more rugose and morphologically complex communities.

  7. Soil Fertility Status, Nutrient Uptake, and Maize (Zea mays L.) Yield Following Organic Matters and P Fertilizer Application on Andisol

    NASA Astrophysics Data System (ADS)

    Minardi, S.; Harieni, S.; Anasrullah, A.; Purwanto, H.

    2017-04-01

    Objective of this study were to elucidate effects of organic matters and P fertilizer application on soil fertility status, nutrient uptake and maize yield in the Andisol. This experiment consisted of two factors. The first factor comprised of four levels of organic matters input (without organic matter, manure, rice straw, and Gliricidia sepium leaves), with the application dosage 10 t.ha-1 and the second factor comprised of three levels of P fertilizer application (without P addition (control), 50 kg P2O5 ha-1, 100 kg P2O5 ha-1). Results of this study showed that organic matters and P fertilizer application improved soil fertility status, especially pH, soil organic C, cation exchange capacity (CEC), available P which resulted in an increase in P uptake that improve yield of maize. The highest yield of maize (corn cob) was obtained through application Gliricida sepium (8.40 t.ha-1), followed by manure (6.02 t.ha-1) and rice straw (5.87 t.ha-1). Application of 50 kg P2O5 Ha-1 yield was (5.76 t.ha-1) and application of 100 Kg P2O5 Ha-1 yield was (6.12 t.ha-1).

  8. Interactive effects of carbon dioxide and nutrient availability on nutrient uptake, allocation and accretion in loblolly pine seedlings (Pinus taeda L. )

    SciTech Connect

    Thomas, R.B.; Strain, B.R. )

    1993-06-01

    Nitrogen and phosphorus content and uptake rates were determined in loblolly pine grown at two CO[sub 2] levels (35 and 65 Pa) and three nutrient levels (7 mM NM[sub 4]NO[sub 3] + 1 mM PO[sub 4]; 7 mM NH[sub 4]NO[sub 3]+ 0.2 mM PO[sub 4]; 1 mM NH[sub 4]NO[sub 3] + 1 mM PO[sub 4]) over one growing season. Neither N uptake nor P uptake rates (on a root weight basis) were affected by CO[sub 2] enrichment in any of the nutrient treatments. Nutrient limitations by either N or P reduced the uptake rates of both N and P by seedlings. As the growing season progressed, leaf N and P concentrations decreased, and with nonlimiting soil N, leaf N was diluted by elevated CO[sub 2]. Leaf P was unaffected by CO[sub 2] enrichment as were concentrations of both N and P in stems and roots. Under nonlimiting N, almost 70% of total plant N was allocated to needles. Greater N was allocated to roots at the expense of leaf N under conditions of low soil N and this was enhanced by CO[sub 2] enrichment. With limiting P, there was almost no change in allocation of N or P, and only a marginal effect of CO[sub 2] enrichment on P allocation. Stimulation of biomass production by elevated CO[sub 2] with no increase in nutrient uptake rates indicates an increase in nutrient use efficiency by the seedlings.

  9. Effects of elevated CO/sub 2/ and nutrient stress on nitrogen and phosphorus uptake and use efficiencies

    SciTech Connect

    Cure, J.D.; Israel, D.W.; Rufty, T.W.

    1987-04-01

    Earlier they reported that non-nodulating Lee soybeans growing in complete nutrient solution showed decreased nutrient uptake efficiency (mg N or P/g root) at early pod fill when exposed to elevated CO/sub 2/. In order to look at CO/sub 2//nutrient interactions over time, plants were grown in growth chambers with nutrient solutions containing 10 mM N/1 mM P (controls) or 10 mM N/0.1 mM P (low P) or 0.5 mM N/1 mMP (low N) and exposed to either 350 or 700 ..mu..L/L CO/sub 2/. Uptake efficiencies for N and P of the control plants showed a pronounced positive response to high CO/sub 2/ in early growth stages, which diminished with time and then became negative. This trend was also present for the low N and low P plants. Nutrient use efficiency, however, was increased by day 7 (first harvest) by high CO/sub 2/ and the effect was sustained through the vegetative period. The N and P stresses produced contrasting responses: low P availability caused an increase in P use efficiency, whereas low N caused a decrease in N use efficiency. These effects resulted from P uptake beyond the requirement for growth, a pattern not observed for N uptake.

  10. Quantifying nutrient uptake as driver of rock weathering in forest ecosystems by magnesium stable isotopes

    NASA Astrophysics Data System (ADS)

    Uhlig, David; Schuessler, Jan A.; Bouchez, Julien; Dixon, Jean L.; von Blanckenburg, Friedhelm

    2017-06-01

    Plants and soil microbiota play an active role in rock weathering and potentially couple weathering at depth with erosion at the soil surface. The nature of this coupling is still unresolved because we lacked means to quantify the passage of chemical elements from rock through higher plants. In a temperate forested landscape characterised by relatively fast (˜ 220 t km-2 yr-1) denudation and a kinetically limited weathering regime of the Southern Sierra Critical Zone Observatory (SSCZO), California, we measured magnesium (Mg) stable isotopes that are sensitive indicators of Mg utilisation by biota. We find that Mg is highly bio-utilised: 50-100 % of the Mg released by chemical weathering is taken up by forest trees. To estimate the tree uptake of other bio-utilised elements (K, Ca, P and Si) we compared the dissolved fluxes of these elements and Mg in rivers with their solubilisation fluxes from rock (rock dissolution flux minus secondary mineral formation flux). We find a deficit in the dissolved fluxes throughout, which we attribute to the nutrient uptake by forest trees. Therefore both the Mg isotopes and the flux comparison suggest that a substantial part of the major element weathering flux is consumed by the tree biomass. The enrichment of 26Mg over 24Mg in tree trunks relative to leaves suggests that tree trunks account for a substantial fraction of the net uptake of Mg. This isotopic and elemental compartment separation is prevented from obliteration (which would occur by Mg redissolution) by two potential effects. Either the mineral nutrients accumulate today in regrowing forest biomass after clear cutting, or they are exported in litter and coarse woody debris (CWD) such that they remain in solid biomass. Over pre-forest-management weathering timescales, this removal flux might have been in operation in the form of natural erosion of CWD. Regardless of the removal mechanism, our approach provides entirely novel means towards the direct

  11. Influence of activated charcoal amendment to contaminated soil on dieldrin and nutrient uptake by cucumbers.

    PubMed

    Hilber, Isabel; Wyss, Gabriela S; Mäder, Paul; Bucheli, Thomas D; Meier, Isabel; Vogt, Lea; Schulin, Rainer

    2009-01-01

    Activated charcoal (AC) amendments have been suggested as a promising, cost-effective method to immobilize organic contaminants in soil. We performed pot experiments over two years with cucumber (Cucumis sativus L.) grown in agricultural soil with 0.07 mg kg(-1) of weathered dieldrin and 0, 200, 400, and 800 mg AC per kg soil. Dieldrin fresh weight concentrations in cucumber fruits were significantly reduced from 0.012 to an average of 0.004 mg kg(-1), and total uptake from 2 to 1 microg in the 800 mg kg(-1) AC treatment compared to the untreated soil. The treatment effects differed considerably between the two years, due to different meteorological conditions. AC soil treatments did neither affect the availability of nutrients to the cucumber plants nor their yield (total fruit wet weight per pot). Thus, some important prerequisites for the successful application of AC amendments to immobilize organic pollutants in agricultural soils can be considered fulfilled.

  12. Interaction with ectomycorrhizal fungi and endophytic Methylobacterium affects nutrient uptake and growth of pine seedlings in vitro.

    PubMed

    Pohjanen, Johanna; Koskimäki, Janne J; Sutela, Suvi; Ardanov, Pavlo; Suorsa, Marja; Niemi, Karoliina; Sarjala, Tytti; Häggman, Hely; Pirttilä, Anna Maria

    2014-09-01

    Tissues of Scots pine (Pinus sylvestris L.) contain several endophytic microorganisms of which Methylobacterium extorquens DSM13060 is a dominant species throughout the year. Similar to other endophytic bacteria, M. extorquens is able to colonize host plant tissues without causing any symptoms of disease. In addition to endophytic bacteria, plants associate simultaneously with a diverse set of microorganisms. Furthermore, plant-colonizing microorganisms interact with each other in a species- or strain-specific manner. Several studies on beneficial microorganisms interacting with plants have been carried out, but few deal with interactions between different symbiotic organisms and specifically, how these interactions affect the growth and development of the host plant. Our aim was to study how the pine endophyte M. extorquens DSM13060 affects pine seedlings and how the co-inoculation with ectomycorrhizal (ECM) fungi [Suillus variegatus (SV) or Pisolithus tinctorius (PT)] alters the response of Scots pine. We determined the growth, polyamine and nutrient contents of inoculated and non-inoculated Scots pine seedlings in vitro. Our results show that M. extorquens is able to improve the growth of seedlings at the same level as the ECM fungi SV and PT do. The effect of co-inoculation using different symbiotic organisms was seen in terms of changes in growth and nutrient uptake. Inoculation using M. extorquens together with ECM fungi improved the growth of the host plant even more than single ECM inoculation. Symbiotic organisms also had a strong effect on the potassium content of the seedling. The results indicate that interaction between endophyte and ECM fungus is species dependent, leading to increased or decreased nutrient content and growth of pine seedlings. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Transcriptomic analysis displays the effect of (-)-roemerine on the motility and nutrient uptake in Escherichia coli.

    PubMed

    Ayyildiz, Dilara; Arga, Kazim Yalcin; Avci, Fatma Gizem; Altinisik, Fatma Ece; Gurer, Caglayan; Gulsoy Toplan, Gizem; Kazan, Dilek; Wozny, Katharina; Brügger, Britta; Mertoglu, Bulent; Sariyar Akbulut, Berna

    2017-08-01

    Among the different families of plant alkaloids, (-)-roemerine, an aporphine type, was recently shown to possess significant antibacterial activity in Escherichia coli. Based on the increasing demand for antibacterials with novel mechanisms of action, the present work investigates the potential of the plant-derived alkaloid (-)-roemerine as an antibacterial in E. coli cells using microarray technology. Analysis of the genome-wide transcriptional reprogramming in cells after 60 min treatment with 100 μg/mL (-)-roemerine showed significant changes in the expression of 241 genes (p value <0.05 and fold change >2). Expression of selected genes was confirmed by qPCR. Differentially expressed genes were classified into functional categories to map biological processes and molecular pathways involved. Cellular activities with roles in carbohydrate transport and metabolism, energy production and conversion, lipid transport and metabolism, amino acid transport and metabolism, two-component signaling systems, and cell motility (in particular, the flagellar organization and motility) were among metabolic processes altered in the presence of (-)-roemerine. The down-regulation of the outer membrane proteins probably led to a decrease in carbohydrate uptake rate, which in turn results in nutrient limitation. Consequently, energy metabolism is slowed down. Interestingly, the majority of the expressional alterations were found in the flagellar system. This suggested reduction in motility and loss in the ability to form biofilms, thus affecting protection of E. coli against host cell defense mechanisms. In summary, our findings suggest that the antimicrobial action of (-)-roemerine in E. coli is linked to disturbances in motility and nutrient uptake.

  14. [Influence of aluminum and manganese on the growth, nutrient uptake and the efflux by ectomycorrhizal fungi].

    PubMed

    Li, Hua; Huang, Jian-Guo; Yuan, Ling

    2013-01-01

    Al3+ and Mn2+ limit forest growth and vegetation restoration in strongly acidic soils and mining areas of aluminum and manganese. The knowledge on the influence of these two elements on ectomycorrhizal fungi can provide theoretical and technical supports for the selection of powerful ectomycorrhizal fungal strains and the bioremediation of contaminated soil. Three ectomycorrhizal fungal strains, namely Suillus luteus 13 (Sl 13), Cenococcum geophilum 04 (Cg 04) and Pisolithus tinctorius 715 (Pt 715), were grown in liquid culture mediums with Al3+ and Mn2+ added alone and together to investigate fungal growth, nutrient uptake and organic acid efflux. The results showed that the biomass of Sl 13, Cg 04 and Pt 715 was decreased by 70.35%, 52.44% and 18.55%, respectively, under Mn2+ stress. Al3 also decreased the biomass of Sl 13 by 50.74% but increased that of Cg 04. The growth of ectomycorrhizal fungi was further inhibited when grown in culture solutions with addition of both Mn2+ and Al3 and the least growth inhibition was found with Pt 715. Cg 04 might thus have a strong resistance to Al3+ stress and Pt 715 to both Al3+ and Mn2+ compared to the others. Al3+ and Mn2+ decreased the nutrient uptake by the fungi, particularly by Sl 13 which showed more obvious reduction than Pt 715 and Cg 04. However, Al3+ and Mn2+ increased the efflux of oxalic acid and protons by ectomycorrhizal fungi. An additional oxalic acid exudation by Cg 04 was observed in the coexistence of Al3+ and Mn2+ and Pt 715 exuded not only oxalic acid but also succinic acid. Therefore, ectomycorrhizal fungi resistant to Mn2+ and Al3+ could effuse more organic acids than the sensitive ones in order to alleviate the harmfulness through complexation under the stress.

  15. Do interventions that improve immunisation uptake also reduce social inequalities in uptake?

    PubMed Central

    Reading, R.; Colver, A.; Openshaw, S.; Jarvis, S.

    1994-01-01

    OBJECTIVE--To investigate whether an intervention designed to improve overall immunisation uptake affected social inequalities in uptake. DESIGN--Cross-sectional small area analyses measuring immunisation uptake in cohorts of children before and after intervention. Small areas classified into five groups, from most deprived to most affluent, with Townsend deprivation score of census enumeration districts. SETTING--County of Northumberland. SUBJECTS--All children born in country in four birth cohorts (1981-2, 1985-6, 1987-8, and 1990-1) and still resident at time of analysis. MAIN OUTCOME MEASURES--Overall uptake in each cohort of pertussis, diphtheria, and measles immunisation, difference in uptake between most deprived and most affluent areas, and odds ratio of uptake between deprived and affluent areas. RESULTS--Coverage for pertussis immunisation rose from 53.4% in first cohort to 91.1% in final cohort. Coverage in the most deprived areas was lower than in the most affluent areas by 4.7%, 8.7%, 10.2%, and 7.0% respectively in successive cohorts, corresponding to an increase in odds ratio of uptake between deprived and affluent areas from 1.2 to 1.6 to 1.9 to 2.3. Coverage for diphtheria immunisation rose from 70.0% to 93.8%; differences between deprived and affluent areas changed from 8.6% to 8.3% to 9.0% to 5.5%, corresponding to odds ratios of 1.5, 2.0, 2.5, and 2.6. Coverage for measles immunisation rose from 52.5% to 91.4%; differences between deprived and affluent areas changed from 9.1% to 5.7% to 8.2% to 3.6%, corresponding to odds ratios of 1.4, 1.4, 1.7, and 1.5. CONCLUSION--Despite substantial increase in immunisation uptake, inequalities between deprived and affluent areas persisted or became wider. Any reduction in inequality occurred only after uptake in affluent areas approached 95%. Interventions that improve overall uptake of preventive measures are unlikely to reduce social inequalities in uptake. PMID:8173457

  16. Improving representation of nitrogen uptake, allocation, and carbon assimilation in the Community Land Model

    NASA Astrophysics Data System (ADS)

    Ghimire, B.; Riley, W. J.; Koven, C.

    2013-12-01

    Nitrogen is the most important nutrient limiting plant carbon assimilation and growth, and is required for production of photosynthetic enzymes, growth and maintenance respiration, and maintaining cell structure. The forecasted rise in plant available nitrogen through atmospheric nitrogen deposition and the release of locked soil nitrogen by permafrost thaw in high latitude ecosystems is likely to result in an increase in plant productivity. However a mechanistic representation of plant nitrogen dynamics is lacking in earth system models. Most earth system models ignore the dynamic nature of plant nutrient uptake and allocation, and further lack tight coupling of below- and above-ground processes. In these models, the increase in nitrogen uptake does not translate to a corresponding increase in photosynthesis parameters, such as maximum Rubisco capacity and electron transfer rate. We present an improved modeling framework implemented in the Community Land Model version 4.5 (CLM4.5) for dynamic plant nutrient uptake, and allocation to different plant parts, including leaf enzymes. This modeling framework relies on imposing a more realistic flexible carbon to nitrogen stoichiometric ratio for different plant parts. The model mechanistically responds to plant nitrogen uptake and leaf allocation though changes in photosynthesis parameters. We produce global simulations, and examine the impacts of the improved nitrogen cycling. The improved model is evaluated against multiple observations including TRY database of global plant traits, nitrogen fertilization observations and 15N tracer studies. Global simulations with this new version of CLM4.5 showed better agreement with the observations than the default CLM4.5-CN model, and captured the underlying mechanisms associated with plant nitrogen cycle.

  17. Oxygen, sulphide and nutrient uptake of the mangrove mud clam Anodontia edentula (Family: Lucinidae).

    PubMed

    Lebata, M J

    2001-11-01

    Oxygen, sulphide and nutrient (ammonia, nitrite and phosphate) uptake of Anodontia edentula was measured. Oxygen and sulphide were measured from sealed containers provided with 1 l fresh mangrove mud (sulphide source) and seawater (oxygen source) with two treatments (with and without clam) at 16 replicates each. Oxygen, sulphide and other parameters were measured at days 1 (initial), 3 and 5 (final). Nutrients were measured from containers filled with 1.5 l wastewater from a milkfish broodstock tank with two treatments (with and without clam) at eight replicates each. Ammonia, NO2 and P04 were measured at days 0 (initial) 3, 6, 9 and 12 (final). Results showed significantly decreasing oxygen and sulphide concentrations in treatment with clams (ANOVA, p < 0.001). A significantly higher ammonia concentration (ANOVA, p < 0.05) was observed in treatment with clams while no significant difference was observed in nitrite and phosphate between the two treatments. A decreasing ammonia and an increasing nitrite trend was also observed in both treatments starting at day 3.

  18. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees

    PubMed Central

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees. PMID:27764099

  19. Liquid Organic Fertilizers for Sustainable Agriculture: Nutrient Uptake of Organic versus Mineral Fertilizers in Citrus Trees.

    PubMed

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Bermejo, Almudena; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    The main objective of this study was to compare the performance of two liquid organic fertilizers, an animal and a plant-based fertilizer, with mineral fertilization on citrus trees. The source of the fertilizer (mineral or organic) had significant effect in the nutritional status of the organic and conventionally managed mandarins. Nutrient uptake, vegetative growth, carbohydrate synthesis and soil characteristics were analyzed. Results showed that plants fertilized with animal based liquid fertilizers exhibited higher total biomass with a more profuse development of new developing organs (leaves and fibrous roots). Liquid organic fertilization resulted in an increased uptake of macro and micronutrients compared to mineral fertilized trees. Moreover, organic fertilization positively affected the carbohydrate content (fructose, glucose and sucrose) mainly in summer flush leaves. Liquid organic fertilization also resulted in an increase of soil organic matter content. Animal-based fertilizer, due to intrinsic composition, increased total tree biomass and carbohydrate leaves content, and led to lower soil nitrate concentration and higher P and Mg exchangeable in soil extract compared to vegetal-based fertilizer. Therefore, liquid organic fertilizers could be used as an alternative to traditional mineral fertilization in drip irrigated citrus trees.

  20. High intraspecific ability to adjust both carbon uptake and allocation under light and nutrient reduction in Halimium halimifolium L.

    PubMed

    Wegener, Frederik; Beyschlag, Wolfram; Werner, Christiane

    2015-01-01

    The allocation of recently assimilated carbon (C) by plants depends on developmental stage and on environmental factors, but the underlying mechanisms are still a matter of debate. In the present study, we investigated the regulation of C uptake and allocation and their adjustments during plant growth. We induced different allocation strategies in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analyzed allocation parameters as well as morphological and physiological traits for 15 months. Further, we conducted a (13)CO2 pulse-labeling and followed the way of recently assimilated carbon to eight different tissue classes and respiration for 13 days. The plant responses were remarkably distinct in our study, with mainly morphological/physiological adaptions in case of light reduction and adjustment of C allocation in case of nutrient reduction. The transport of recently assimilated C to the root system was enhanced in amount (c. 200%) and velocity under nutrient limited conditions compared to control plants. Despite the 57% light reduction the total biomass production was not affected in the Low L treatment. The plants probably compensated light reduction by an improvement of their ability to fix C. Thus, our results support the concept that photosynthesis is, at least in a medium term perspective, influenced by the C demand of the plant and not exclusively by environmental factors. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C reflux from storage and structural C pools and therefore enhance the fraction of recent assimilates allocated to respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a regulation mechanism for C translocation in plants.

  1. High intraspecific ability to adjust both carbon uptake and allocation under light and nutrient reduction in Halimium halimifolium L.

    PubMed Central

    Wegener, Frederik; Beyschlag, Wolfram; Werner, Christiane

    2015-01-01

    The allocation of recently assimilated carbon (C) by plants depends on developmental stage and on environmental factors, but the underlying mechanisms are still a matter of debate. In the present study, we investigated the regulation of C uptake and allocation and their adjustments during plant growth. We induced different allocation strategies in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analyzed allocation parameters as well as morphological and physiological traits for 15 months. Further, we conducted a 13CO2 pulse-labeling and followed the way of recently assimilated carbon to eight different tissue classes and respiration for 13 days. The plant responses were remarkably distinct in our study, with mainly morphological/physiological adaptions in case of light reduction and adjustment of C allocation in case of nutrient reduction. The transport of recently assimilated C to the root system was enhanced in amount (c. 200%) and velocity under nutrient limited conditions compared to control plants. Despite the 57% light reduction the total biomass production was not affected in the Low L treatment. The plants probably compensated light reduction by an improvement of their ability to fix C. Thus, our results support the concept that photosynthesis is, at least in a medium term perspective, influenced by the C demand of the plant and not exclusively by environmental factors. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C reflux from storage and structural C pools and therefore enhance the fraction of recent assimilates allocated to respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a regulation mechanism for C translocation in plants. PMID:26300906

  2. Age-related changes in oxygen and nutrient uptake by hindquarters in newborn pigs during cold-induced shivering.

    PubMed

    Lossec, G; Lebreton, Y; Hulin, J C; Fillaut, M; Herpin, P

    1998-11-01

    Newborn pigs rely essentially on shivering thermogenesis in the cold. In order to understand the rapid postnatal enhancement of thermogenic capacities in piglets, the oxygen and nutrient uptake of hindquarters was measured in vivo in 1- (n = 6) and 5-day-old (n = 6) animals at thermal neutrality and during cold exposure. The hindquarters were considered to represent a skeletal muscle compartment. Indirect calorimetry and arterio-venous techniques were used. The cold challenge (23 C at 1 day old and 15 C at 5 days old for 90 min) induced a similar increase (+90 %) in regulatory heat production at both ages. Hindquarters blood flow was higher at 5 days than 1 day old at thermal neutrality (26 +/- 3 vs. 17 +/- 1 ml min-1 (100 g hindquarters)-1) and its increase in the cold was much more marked (+65 % at 5 days old vs. +25 % at 1 day old). Oxygen extraction by the hindquarters rose from 30-35 % at thermal neutrality to 65-70 % in the cold at both ages. The calculated contribution of skeletal muscle to total oxygen consumption averaged 34-40 % at thermal neutrality and 50-64 % in the cold and skeletal muscle was the major contributor to regulatory thermogenesis. Based on hindquarters glucose uptake and lactate release, carbohydrate appeared to be an important fuel for shivering. However, net uptake of fatty acids increased progressively during cold exposure at 5 days old. The enhancement in muscular blood supply and fatty acid utilization during shivering is probably related to the postnatal improvement in the thermoregulatory response of the piglet.

  3. Irrigation frequency during container production alters Rhodendron growth, nutrient uptake, and flowering after transplanting into a landscape

    USDA-ARS?s Scientific Manuscript database

    The influence of irrigation frequency (same amount of water per day given at different times) and nitrogen (N) fertilizer application rate during container on nutrient uptake, growth (biomass) and flowering of evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhod...

  4. Irrigation frequency alters nutrient uptake in container-grown Rhododendron plants grown with different rates of nitrogen

    USDA-ARS?s Scientific Manuscript database

    The influence of irrigation frequency (same amount of water per day given at different times) on nutrient uptake of container-grown evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ) grown with different rates of nitrogen (N) fertilize...

  5. Uptake of macro- and micro-nutrients into leaf, woody, and root tissue of Populus after irrigation with landfill leachate

    Treesearch

    Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Bart T. Sexton; Richard B. Hall

    2008-01-01

    Information about macro- and micro-nutrient uptake and distribution into tissues of Populus irrigated with landfill leachate helps to maximize biomass production and understand impacts of leachate chemistry on tree health. We irrigated eight Populus clones (NC 13460, NCI4O18, NC14104, NC14106, DM115, DN5, NM2, NM6) with fertilized (N, P, K) well...

  6. Effects of acidic deposition on nutrient uptake, nutrient cycling and growth processes of vegetation in the spruce-fir ecosystem

    SciTech Connect

    McLaughlin, S.B.; Garten, C.T.; Wullschleger, S.D.

    1996-10-16

    This report summarizes progress in three years of field research designed to evaluate biological and chemical indicators of the current and future health of the Southern Appalachian spruce-fir ecosystem. The emphasis of this research has been on the identification and understanding of mechanisms through which current levels of acidic deposition are impacting ecosystem processes. The identification of these principal mechanisms and key biological indicators of change was designed to improve our capabilities to detect, monitor, and assess the effects of air quality regulations and attendant future air quality changes on ecosystem response. Individual research tasks focused on the following research areas: (1) the significance of foliar uptake of atmospheric sources of nitrogen in relationship to plant utilization of N from available soil reserves; (2) linkages between atmospheric inputs to the soil surface, solution chemistry, and decomposition in the upper organic soil horizons; (3) effects of soil solution chemistry on uptake of cations and aluminum by fine roots; and (4) the effects of varying rates of calcium supply on carbon metabolism of Fraser fir and red spruce, and the relationship between calcium levels in wood cells and integrity of wood formed in bole and branches. Each of the individual tasks was designed to focus upon a mechanism or process that we consider critical to understanding chemical and biological linkages. These linkages will be important determinants in understanding the basis of past and potential future responses of the high elevation Southern Appalachian Forest to acidic deposition and other co-occurring environmental stresses. This report contains (1) background and rationale for the research undertaken in 1992-94; (2) a summary of principal research findings; (3) publications from this research; and (4) characterization of data sets produced by this research which will be the basis of future research, analyses and/or publications.

  7. A H+-ATPase That Energizes Nutrient Uptake during Mycorrhizal Symbioses in Rice and Medicago truncatula[C][W][OPEN

    PubMed Central

    Wang, Ertao; Yu, Nan; Bano, S. Asma; Liu, Chengwu; Miller, Anthony J.; Cousins, Donna; Zhang, Xiaowei; Ratet, Pascal; Tadege, Million; Mysore, Kirankumar S.; Downie, J. Allan; Murray, Jeremy D.; Oldroyd, Giles E.D.; Schultze, Michael

    2014-01-01

    Most plant species form symbioses with arbuscular mycorrhizal (AM) fungi, which facilitate the uptake of mineral nutrients such as phosphate from the soil. Several transporters, particularly proton-coupled phosphate transporters, have been identified on both the plant and fungal membranes and contribute to delivering phosphate from fungi to plants. The mechanism of nutrient exchange has been studied in plants during mycorrhizal colonization, but the source of the electrochemical proton gradient that drives nutrient exchange is not known. Here, we show that plasma membrane H+-ATPases that are specifically induced in arbuscule-containing cells are required for enhanced proton pumping activity in membrane vesicles from AM-colonized roots of rice (Oryza sativa) and Medicago truncatula. Mutation of the H+-ATPases reduced arbuscule size and impaired nutrient uptake by the host plant through the mycorrhizal symbiosis. Overexpression of the H+-ATPase Os-HA1 increased both phosphate uptake and the plasma membrane potential, suggesting that this H+-ATPase plays a key role in energizing the periarbuscular membrane, thereby facilitating nutrient exchange in arbusculated plant cells. PMID:24781115

  8. The effects of weed-crop competition on nutrient uptake as affected by crop rotation and fertilizers.

    PubMed

    Mohammaddoust-E-Chamanabad, Hamid Reza; Asghari, Ali; Tulikov, Aleksander Mikhailovic

    2007-11-15

    A field study at the Agricultural University of Timiriazev, Moscow, was conducted to determine the effect of crop rotation and Long-term fertilizer application on differences in the competitive ability of spring barley and weeds to nutrient uptake in 2004 and 2005. Spring barley was cultivated in continuous and in crop rotation with winter rye, potato, clover, flax and fallow, with and without NPK application since 1912. Spring barley, especially in no fertilizer plots grown in crop rotation has greater dry mass than spring barley grown in continuous. While dry weed mass markedly decreased in crop rotation. Decrease dry weeds mass was greater when NPK had applied. The statistical analyses show that when spring barley grew in competition with weeds in the no fertilizer plots, crop rotation significantly increased nutrient content in spring barley, but when fertilizer applied the content of N, P2O5 and K2O in barley did not change. Lowest weeds nutrient content observed where soil fertility was increased by crop rotation and NPK application. Crop rotation significantly increased total nutrient uptake of soils by spring barley, but decreased total nutrient uptake by weeds.

  9. The effect of titanium amendment in N-withholding nutrient solution on physiological and photosynthesis attributes and micronutrient uptake of tomato.

    PubMed

    Haghighi, Maryam; Heidarian, Salman; Teixeira da Silva, Jaime A

    2012-12-01

    Titanium (Ti) is a beneficial element that promotes growth and biomass production although the mechanism by which this improvement takes place is still unclear, as are other effects on plants, although it is believed that Ti can compensate for N deficiency. To prove this hypothesis, a hydroponic experiment was designed to investigate the effect of adding Ti to a nutrient solution on the nutrient uptake of tomato (Lycopersicon esculentum L.) by withholding N within the nutrient solution (NS) by 25 % (NS2) and by 50 % (NS1). Ti was added at 1 and 2 mg L⁻¹. When Ti was added to nutrient solution, the elemental concentration in tomato changed significantly: K, Ca, Fe, and Zn decreased while Ti increased. As the concentration of N in nutrient solution decreased, the Ca and Ti concentration of tomato leaves decreased and the K, Mn, Fe, Cu, and Zn concentration increased. As the N concentration in nutrient solution increased, the Ca concentration decreased although the application of Ti compensated for Ca concentration in NS1. All the photosynthetic attributes and physiological characteristics, including flower induction, decreased when the N concentration of NS decreased by 50 %, although this decrease could be compensated by applying 1 mg L⁻¹ Ti. This has valuable and practical applications and implications for tomato hydroponic culture.

  10. Interference of three weed extracts on uptake of nutrient in three different varieties of paddy through radio tracer techniques.

    PubMed

    Saxena, S; Sharma, K; Kumar, Surendra; Sand, N K; Rao, P B

    2004-10-01

    Interference of three dominant weed extracts viz., Ageratum conyzoides L., Melilotus indica All. and Parthenium hysterophorus L. were examined on seed germination, seedling growth, and nutrient uptake (32P and 65Zn) in three different varieties (PD-10, PD-12 and PB) of paddy (Oryza sativa L.). Among the three different varieties irrespective of weed extracts, PD-10 and PD-12 were resistant and PB was susceptible in terms of seed germination, radicle length and plumule dry weight; and PD-12 and PB were resistant and susceptible, respectively, in terms of plumule length and total seedling dry weight. A. conyzoides caused maximum reduction in seed germination and M. indica in seedling growth in different varieties of paddy. The weed extracts interfered in uptake of both 32P and 65Zn and there was a gradual decrease in uptake of both nutrients with increasing concentration of extracts in both root and shoot. The uptake of 32P and 65Zn was more inhibitory with the extracts of A. conyzoides and M. indica, respectively in different varieties. The inhibition in seed germination, seedling growth and nutrient uptake may be due to the presence of phenolics and other secondary metabolities. The phenolics such as gallic, vanillic, protocatechuic and p-hydroxybenzoic acids were identified from these weed extracts.

  11. Plant uptake of cations under nutrient limitation: An environmental tracer study using Ca/Sr and K/Rb ratios

    NASA Astrophysics Data System (ADS)

    Shi, Z.; Keller, C. K.; Stacks, D.; Grant, M.; Harsh, J. B.; Letourneau, M.; Gill, R. A.; Balogh-Brunstad, Z.; Thomashow, L.; Dohnalkova, A.

    2012-12-01

    Vascular plant growth builds soils and ecosystem nutrient capital by sequestering and partitioning atmospheric CO2 into organic matter and continental runoff and driving terrestrial water and energy balances. Plant root-system functions, e.g. nutrient mobilization and uptake, are altered by environmental stress. However, the stress-response relationships are poorly understood. Chemical tracers have potential for assessing contributions of nutrients from various nutrient pools. Our objective is to quantitatively study how varying degrees of nutrient limitation (and corresponding needs to extract base cations from mineral sources) influence Ca and K uptake functions in a plant-root-mineral system. We are studying plant-driven mineral weathering in column experiments with red pine (Pinus resinosa) seedlings. The columns contain quartz sand amended with anorthite and biotite that constitute the sole mineral sources of Ca and K. These minerals also contain known amounts of Sr and Rb, which exhibit chemical behavior similar to Ca and K, respectively. The solution source of Ca and K was varied by adding 0% (no dissolved Ca and K), 10%, 30%, or 100% of a full strength Ca and K nutrient solution through irrigation water in which both Sr and Rb concentrations were negligible. Selected columns were destructively sampled at 3, 6 and 9 months to harvest biomass and measure plant uptake of cations. We used Ca/Sr and K/Rb ratio results to estimate the contributions of Ca and K from mineral and solution sources. For the 0% nutrient treatment, the Ca/Sr and K/Rb ratios in total biomass at 3 months, compared with those in the mineral phases, suggested preferential uptake of Ca and K over Sr and Rb, respectively, and allowed us to determine uptake discrimination factors for both cations. The K/Rb ratios in total biomass increased with greater K availability in the solution source, as expected, but Ca/Sr ratios did not show any dependence on Ca availability in the solution source

  12. Hydrological management for improving nutrient assimilative capacity in plant-dominated wetlands: A modelling approach.

    PubMed

    Xu, Zhihao; Yang, Zhifeng; Yin, Xinan; Cai, Yanpeng; Sun, Tao

    2016-07-15

    Wetland eutrophication is a global environmental problem. Besides reducing pollutant emissions, improving nutrient assimilative capacity in wetlands is also significant for preventing eutrophication. Hydrological management can improve nutrient assimilative capacity in wetlands through physical effects on the dilution capacity of water body and ecological effects on wetland nutrient cycles. The ecological effects are significant while were rarely considered in previous research. This study focused on the ecological effects of hydrological management on two crucial nutrient removal processes, plant uptake and biological denitrification, in plant-dominated wetlands. A dual-objective optimization model for hydrological management was developed to improve wetland nitrogen and phosphorus assimilative capacities, using upstream reservoir release as water regulating measure. The model considered the interactions between ecological processes and hydrological cycles in wetlands, and their joint effects on nutrient assimilative capacity. Baiyangdian Wetland, the largest freshwater wetland in northern China, was chosen as a case study. The results found that the annual total assimilative capacity of nitrogen (phosphorus) was 4754 (493) t under the optimal scheme for upstream reservoir operation. The capacity of nutrient removal during the summer season accounted for over 80% of the annual total removal capacity. It was interesting to find that the relationship between water inflow and nutrient assimilative capacity in a plant-dominated wetland satisfied a dose-response relationship commonly describing the response of an organism to an external stressor in the medical field. It illustrates that a plant-dominated wetland shows similar characteristics to an organism. This study offers a useful tool and some fresh implications for future management of wetland eutrophication prevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The role of carbon in fungal nutrient uptake and transport: implications for resource exchange in the arbuscular mycorrhizal symbiosis.

    PubMed

    Fellbaum, Carl R; Mensah, Jerry A; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2012-11-01

    The arbuscular mycorrhizal (AM) symbiosis, which forms between plant hosts and ubiquitous soil fungi of the phylum Glomeromycota, plays a key role for the nutrient uptake of the majority of land plants, including many economically important crop species. AM fungi take up nutrients from the soil and exchange them for photosynthetically fixed carbon from the host. While our understanding of the exact mechanisms controlling carbon and nutrient exchange is still limited, we recently demonstrated that (i) carbon acts as an important trigger for fungal N uptake and transport, (ii) the fungus changes its strategy in response to an exogenous supply of carbon, and that (iii) both plants and fungi reciprocally reward resources to those partners providing more benefit. Here, we summarize recent research findings and discuss the implications of these results for fungal and plant control of resource exchange in the AM symbiosis.

  14. Studies on nutrient uptake of rice and characteristics of soil microorganisms in a long-term fertilization experiments for irrigated rice.

    PubMed

    Zhang, Qi-chun; Wang, Guang-huo

    2005-02-01

    The ecosystem characteristics of soil microorganism and the nutrient uptake of irrigated rice were investigated in a split-block experiment with different fertilization treatments, including control (no fertilizer application), PK, NK, NP, NPK fertilization, in the main block, and conventional rice and hybrid rice comparison, in the sub block. Average data of five treatments in five years indicated that the indigenous N supply (INS) capacity ranged from 32.72 to 93.21 kg/ha; that indigenous P supply (IPS) capacity ranged from 7.42 to 32.25 kg/ha; and that indigenous K supply (IKS) capacity ranged from 16.24 to 140.51 kg/ha, which showed that soil available nutrient pool depletion might occur very fast and that P, K deficiency has become a constraint to increasing yields of consecutive crops grown without fertilizer application. It was found that soil nutrient deficiency and unbalanced fertilization to rice crop had negative effect on the diversity of the microbial community and total microbial biomass in the soil. The long-term fertilizer experiment (LTFE) also showed that balanced application of N, P and K promoted microbial biomass growth and improvement of community composition. Unbalanced fertilization reduced microbial N and increased C/N ratio of the microbial biomass. Compared with inbred rice, hybrid rice behavior is characterized by physiological advantage in nutrient uptake and lower internal K use efficiency.

  15. Studies on nutrient uptake of rice and characteristics of soil microorganisms in a long-term fertilization experiments for irrigated rice*

    PubMed Central

    Zhang, Qi-chun; Wang, Guang-huo

    2005-01-01

    The ecosystem characteristics of soil microorganism and the nutrient uptake of irrigated rice were investigated in a split-block experiment with different fertilization treatments, including control (no fertilizer application), PK, NK, NP, NPK fertilization, in the main block, and conventional rice and hybrid rice comparison, in the sub block. Average data of five treatments in five years indicated that the indigenous N supply (INS) capacity ranged from 32.72 to 93.21 kg/ha; that indigenous P supply (IPS) capacity ranged from 7.42 to 32.25 kg/ha; and that indigenous K supply (IKS) capacity ranged from 16.24 to 140.51 kg/ha, which showed that soil available nutrient pool depletion might occur very fast and that P, K deficiency has become a constraint to increasing yields of consecutive crops grown without fertilizer application. It was found that soil nutrient deficiency and unbalanced fertilization to rice crop had negative effect on the diversity of the microbial community and total microbial biomass in the soil. The long-term fertilizer experiment (LTFE) also showed that balanced application of N, P and K promoted microbial biomass growth and improvement of community composition. Unbalanced fertilization reduced microbial N and increased C/N ratio of the microbial biomass. Compared with inbred rice, hybrid rice behavior is characterized by physiological advantage in nutrient uptake and lower internal K use efficiency. PMID:15633252

  16. Nutrient uptake by agricultural crops from biochar-amended soils: results from two field experiments in Austria

    NASA Astrophysics Data System (ADS)

    Karer, Jasmin; Zehetner, Franz; Kloss, Stefanie; Wimmer, Bernhard; Soja, Gerhard

    2013-04-01

    The use of biochar as soil amendment is considered as a promising agricultural soil management technique, combining carbon sequestration and soil fertility improvements. These expectations are largely founded on positive experiences with biochar applications to impoverished or degraded tropical soils. The validity of these results for soils in temperate climates needs confirmation from field experiments with typical soils representative for intensive agricultural production areas. Frequently biochar is mixed with other organic additives like compost. As these two materials interact with each other and each one may vary considerably in its basic characteristics, it is difficult to attribute the effects of the combined additive to one of its components and to a specific physico-chemical parameter. Therefore investigations of the amendment efficacy require the study of the pure components to characterize their specific behavior in soil. This is especially important for adsorption behavior of biochar for macro- and micronutrients because in soil there are multiple nutrient sinks that compete with plant roots for vital elements. Therefore this contribution presents results from a field amendment study with pure biochar that had the objective to characterize the macro- and microelement uptake of crops from different soils in two typical Austrian areas of agricultural production. At two locations in North and South-East Austria, two identical field experiments on different soils (Chernozem and Cambisol) were installed in 2011 with varying biochar additions (0, 30 and 90 t/ha) and two nitrogen levels. The biochar was a product from slow pyrolysis of wood (SC Romchar SRL). During the installation of the experiments, the biochar fraction of <2 mm was mixed with surface soil to a depth of 15 cm in plots of 33 m2 each (n=4). Barley (at the Chernozem soil) and maize (at the Cambisol) were cultivated according to standard agricultural practices. The highest crop yields at both

  17. Modulation of the uptake of critical nutrients by breast cancer cells by lactate: Impact on cell survival, proliferation and migration.

    PubMed

    Guedes, Marta; Araújo, João R; Correia-Branco, Ana; Gregório, Inês; Martel, Fátima; Keating, Elisa

    2016-02-15

    This work aimed to characterize the uptake of folate and glucose by breast cancer cells and to study the effect of lactate upon the transport of these nutrients and upon cell viability, proliferation and migration capacity. Data obtained showed that: a) MCF7 cells uptake (3)H-folic acid ((3)H-FA) at physiological but not at acidic pH; b) T47D cells accumulate (3)H-FA and (14)C-5-methyltetrahydrofolate ((14)C-5-MTHF) more efficiently at acidic than at physiological pH; c) (3)H-deoxyglucose ((3)H-DG) uptake by T47D cells is sodium-independent, inhibited by cytochalasin B (CYT B) and stimulated by insulin. Regarding the effect of lactate, in T47D cells, acute (26 min) and chronic (24 h) exposure to lactic acid (LA) stimulated (3)H-FA uptake. Acute exposure to LA also stimulated (3)H-DG uptake and chronic exposure to LA significantly stimulated T47D cell migratory capacity. In conclusion, the transport of folates is strikingly different in two phenotypically similar breast cancer cell lines: MCF7 and T47D cells. Additionally, lactate seems to act as a signaling molecule which increases the uptake of nutrients and promotes the migration capacity of T47D cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Similarity of nutrient uptake and root dimensions of Engelmann spruce and subalpine fir at two contrasting sites in Colorado

    SciTech Connect

    Yanai, R; McFarlane, K; Lucash, M; Kulpa, S; Wood, D

    2009-10-09

    Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96 hours, and solutions were analyzed for ammonium, nitrate, calcium, magnesium, and potassium. Surprisingly, the two species were indistinguishable in nutrient uptake within site for all nutrients (P > 0.25), but uptake rates differed by site. In general, nutrient uptake was higher at Fraser (P = 0.01, 0.15, 0.03, 0.18 for NH{sub 4}{sup +}, NO{sub 3}{sup -}, Ca{sup 2+}, and K{sup +}, respectively), which is west of the Continental Divide and has lower atmospheric deposition of N than Loch Vale. Mean uptake rates by site for ambient solution concentrations were 0.12 {micro}mol NH{sub 4}{sup +} g{sub fwt}{sup -1} h{sup -1}, 0.02 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1}, 0.21 {micro}mol Ca{sup 2+} g{sub fwt}{sup -1} h{sup -1}, and 0.01 {micro}mol Mg{sup 2+} g{sub fwt}{sup -1} h{sup -1} at Loch Vale, and 0.21 {micro}mol NH{sub 4}{sup +} f{sub fwt}{sup -1}h{sup -1}, 0.04 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1} h{sup -1}, 0.51 {micro}mol Ca{sup 2+}g{sub fwt}{sup -1}h{sup -1}, and 0.07 {micro}mol Mg{sup 2+} f{sub fwt}{sup -1}h{sup -1} at Fraser. The importance of site conditions in determining uptake capacity should not be overlooked when parameterizing nutrient uptake models. We also characterized the root morphology of these two species and compared them to other tree species we have measured at various sites in the northeastern USA. Engelman spruce and subalpine fir

  19. [Pb, Zn accumulation and nutrient uptake of 15 plant species grown in abandoned mine tailings].

    PubMed

    Shi, Xiang; Chen, Yi-Tai; Wang, Shu-Feng; Li, Jiang-Chuan

    2012-06-01

    Vegetation restoration field test was carried out in the abandoned lead-zinc tailings for 3 years. The study showed that accumulation of lead (Pb), zinc (Zn) and nutrient uptake differed with plant species and organs, heavy metals, and planting time. Pb was mainly accumulated in tree roots, and its content distribution in tree organs was generally in the order of roots > leaves > stems. But Zn concentrations in leaves of several tree species were higher than those in roots and stems. Within the tested 15 species, Cercis Canadensis had the highest concentrations of Pb and Zn in roots (1 803 and 2120 mg x kg(-1), respectively). Rhus chinensis had the highest Pb concentration in stems and leaves (280 and 546 mg x kg(-1), respectively) and Zn concentration (1 507 mg x kg(-1)) in leaves. Zn concentration in stems and leaves of Salix matsudana (729 and 1 153 mg x kg(-1), respectively) were the highest. Among the tested 15 species, TF values for Pb of Liquidambar formosana, Medicago sativa, and for Zn of Salix matsudana, Rhus chinensis, Medicago sativa were higher than 1. BCF values for Pb were all lower than 0.17, while that for Zn were all lower than 0.44. The N contents in nitrogen-fixing plants, P contents in Rhus typhina and Ailanthus altissima, and K content in Nerium indicum were significantly higher than those in other plants. With the increase of planting time, concentrations of heavy metal in plant body increased significantly; however the inverse trend were observed in nutritional element content. The species have higher metal accumulation capacity, such as Rhus chinensis, Salix matsudana and those nitrogen-fixing plants have higher tolerance to metal contamination and nutrient deficiency, such as Amorpha fruticosa, Medicago sativa, Lespedeza cuneata, and Alnus cremastogyne, they were suitable as the phytostabilizers in abandoned mine tailings.

  20. Strategic enhancement of algal biomass, nutrient uptake and lipid through statistical optimization of nutrient supplementation in coupling Scenedesmus obliquus-like microalgae cultivation and municipal wastewater treatment.

    PubMed

    Zhang, Chunmin; Zhang, Yalei; Zhuang, Baolu; Zhou, Xuefei

    2014-11-01

    Supplementing proper nutrients could be a strategy for enhancing algal biomass, nutrients uptake and lipid accumulation in the coupling system of biodiesel production and municipal wastewater treatment. However, there is scant information reporting systematic studies on screening and optimization of key supplemented components in the coupling system. The main factors were scientifically screened and optimized using statistical methods. Plackett-Burman design (PBD) was used to explore the roles of added nutrient factors, whereas response surface methodology (RSM) was employed for optimization. Based on the statistic analysis, the optimum added TP and FeCl3·6H2O concentrations for Scenedesmus obliquus-like microalgae growth, nutrients uptake and lipid accumulation were 4.41 mg L(-1) and 6.48 mg L(-1), respectively. The corresponding biomass, lipid content and TN/TP removal efficiency were 1.46 g L(-1), 36.26% and >99%. The predicted value agreed well with the experimental value, as determined by validation experiments, which confirmed the availability and accuracy of the model.

  1. Biochar and manure affect calcareous soil and corn silage nutrient concentrations and uptake.

    PubMed

    Lentz, R D; Ippolito, J A

    2012-01-01

    Carbon-rich biochar derived from the pyrolysis of biomass can sequester atmospheric CO, mitigate climate change, and potentially increase crop productivity. However, research is needed to confirm the suitability and sustainability of biochar application to different soils. To an irrigated calcareous soil, we applied stockpiled dairy manure (42 Mg ha dry wt) and hardwood-derived biochar (22.4 Mg ha), singly and in combination with manure, along with a control, yielding four treatments. Nitrogen fertilizer was applied when needed (based on preseason soil test N and crop requirements) in all plots and years, with N mineralized from added manure included in this determination. Available soil nutrients (NH-N; NO-N; Olsen P; and diethylenetriaminepentaacetic acid-extractable K, Mg, Na, Cu, Mn, Zn, and Fe), total C (TC), total N (TN), total organic C (TOC), and pH were evaluated annually, and silage corn nutrient concentration, yield, and uptake were measured over two growing seasons. Biochar treatment resulted in a 1.5-fold increase in available soil Mn and a 1.4-fold increase in TC and TOC, whereas manure produced a 1.2- to 1.7-fold increase in available nutrients (except Fe), compared with controls. In 2009 biochar increased corn silage B concentration but produced no yield increase; in 2010 biochar decreased corn silage TN (33%), S (7%) concentrations, and yield (36%) relative to controls. Manure produced a 1.3-fold increase in corn silage Cu, Mn, S, Mg, K, and TN concentrations and yield compared with the control in 2010. The combined biochar-manure effects were not synergistic except in the case of available soil Mn. In these calcareous soils, biochar did not alter pH or availability of P and cations, as is typically observed for acidic soils. If the second year results are representative, they suggest that biochar applications to calcareous soils may lead to reduced N availability, requiring additional soil N inputs to maintain yield targets.

  2. Motivational interviewing to improve health screening uptake: A systematic review.

    PubMed

    Miller, Sarah J; Foran-Tuller, Kelly; Ledergerber, Jessica; Jandorf, Lina

    2017-02-01

    Health screenings, physical tests that diagnose disease, are underutilized. Motivational interviewing (MI) may increase health screening rates. This paper systematically reviewed the published articles that examined the efficacy of MI for improving health screening uptake. Articles published before April 28, 2015 were reviewed from PubMed, PsycINFO, and CINAHL. Study methodology, participant demographics, outcomes and quality were extracted from each article. Of the 1573 abstracts, 13 met inclusion criteria. Of the 13 studies, 6 found MI more efficacious than a control, 2 found MI more efficacious than a weak control yet equivalent to an active control, and 3 found MI was not significantly better than a control. Two single arm studies reported improvements in health screening rates following an MI intervention. MI shows promise for improving health screening uptake. However, given the mixed results, the variability amongst the studies and the limited number of randomized trials, it is difficult to discern the exact impact of MI on health screening uptake. Future research is needed to better understand the impact of MI in this context. Such research would determine whether MI should be integrated into standard clinical practice for improving health screening uptake. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Land application of domestic effluent onto four soil types: plant uptake and nutrient leaching.

    PubMed

    Barton, L; Schipper, L A; Barkle, G F; McLeod, M; Speir, T W; Taylor, M D; McGill, A C; van Schaik, A P; Fitzgerald, N B; Pandey, S P

    2005-01-01

    Land application has become a widely applied method for treating wastewater. However, it is not always clear which soil-plant systems should be used, or why. The objectives of our study were to determine if four contrasting soils, from which the pasture is regularly cut and removed, varied in their ability to assimilate nutrients from secondary-treated domestic effluent under high hydraulic loadings, in comparison with unirrigated, fertilized pasture. Grassed intact soil cores (500 mm in diameter by 700 mm in depth) were irrigated (50 mm wk(-1)) with secondary-treated domestic effluent for two years. Soils included a well-drained Allophanic Soil (Typic Hapludand), a poorly drained Gley Soil (Typic Endoaquept), a well-drained Pumice Soil formed from rhyolitic tephra (Typic Udivitrand), and a well-drained Recent Soil formed in a sand dune (Typic Udipsamment). Effluent-irrigated soils received between 746 and 815 kg N ha(-1) and 283 and 331 kg P ha(-1) over two years of irrigation, and unirrigated treatments received 200 kg N ha(-1) and 100 kg P ha(-1) of dissolved inorganic fertilizer over the same period. Applying effluent significantly increased plant uptake of N and P from all soil types. For the effluent-irrigated soils plant N uptake ranged from 186 to 437 kg N ha(-1) yr(-1), while plant P uptake ranged from 40 to 88 kg P ha(-1) yr(-1) for the effluent-irrigated soils. Applying effluent significantly increased N leaching losses from Gley and Recent Soils, and after two years ranged from 17 to 184 kg N ha(-1) depending on soil type. Effluent irrigation only increased P leaching from the Gley Soil. All P leaching losses were less than 49 kg P ha(-1) after two years. The N and P leached from effluent treatments were mainly in organic form (69-87% organic N and 35-65% unreactive P). Greater N and P leaching losses from the irrigated Gley Soil were attributed to preferential flow that reduced contact between the effluent and the soil matrix. Increased N leaching from

  4. Effects of ammonium and nitrate on nutrient uptake and activity of nitrogen assimilating enzymes in western hemlock

    SciTech Connect

    Knoepp, J.D.; Turner, D.P.; Tingey, D.T.

    1993-01-01

    Western hemlock seedlings were grown in nutrient solutions with ammonium, nitrate or ammonium plus nitrate as nitrogen sources. The objectives were to examine (1) possible selectivity for ammonium or nitrate as an N source, (2) the maintenance of charge balance during ammonium and nitrate uptake, and (3) the activity of the nitrogen assimilating enzymes, nitrate reductase, glutamine synthetase, and glutamine dehydrogenase, in relation to the uptake of different nitrogen sources. The uptake studies revealed that western hemlock takes up ammonium faster than nitrate and that ammonium partially inhibits nitrate uptake. Nitrate reductase activity varied with nitrate availability in root tissue, but showed no response in needles, indicating that most nitrate is reduced in the roots. Results indicate that western hemlock may be adapted to sites where NH(4+) is the predominate N source.

  5. Effect on pCO2 by phytoplankton uptake of dissolved organic nutrients in the Central and Northern Baltic Sea, a model study

    NASA Astrophysics Data System (ADS)

    Edman, Moa K.; Anderson, Leif G.

    2014-11-01

    Dissolved organic matter (DOM) has been added to an existing biogeochemical model and the phytoplankton were allowed to utilize the dissolved organic nutrients for primary production. The results show typical vertical structures for dissolved organic carbon (DOC), and improved or maintained model skill for both mean vertical profiles and mean seasonal variation of biogeochemical variables, evaluated by objective skill metrics. Due to scarce DOM measurements in the Baltic Sea it was hard to validate the new variables, but the model can recreate the general magnitude and distribution of terrestrial and in situ produced DOC, DON, and DOP, as far as we know them. The improvements are especially clear for the total nutrient levels and in recreating the biological drawdown of CO2 in the Eastern Gotland basin. Without phytoplankton uptake of dissolved organic nitrogen and phosphate, CO2 assimilation is lower during the summer months and the partial pressure of CO2 increases by about 200 μatm in the Eastern Gotland Basin, while in the Bothnian Bay, both the duration and magnitude of CO2 assimilation are halved. Thus the phytoplankton uptake of dissolved organic nutrients lowers pCO2 in both basins. Variations in the river transported DOM concentration mainly affect the magnitude of the summer cyanobacteria bloom.

  6. Inhibition of nitrification in municipal wastewater-treating photobioreactors: Effect on algal growth and nutrient uptake.

    PubMed

    Krustok, I; Odlare, M; Truu, J; Nehrenheim, E

    2016-02-01

    The effect of inhibiting nitrification on algal growth and nutrient uptake was studied in photobioreactors treating municipal wastewater. As previous studies have indicated that algae prefer certain nitrogen species to others, and because nitrifying bacteria are inhibited by microalgae, it is important to shed more light on these interactions. In this study allylthiourea (ATU) was used to inhibit nitrification in wastewater-treating photobioreactors. The nitrification-inhibited reactors were compared to control reactors with no ATU added. Microalgae had higher growth in the inhibited reactors, resulting in a higher chlorophyll a concentration. The species mix also differed, with Chlorella and Scenedesmus being the dominant genera in the control reactors and Cryptomonas and Chlorella dominating in the inhibited reactors. The nitrogen speciation in the reactors after 8 days incubation was also different in the two setups, with N existing mostly as NH4-N in the inhibited reactors and as NO3-N in the control reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Structure of the trypanosome haptoglobin–hemoglobin receptor and implications for nutrient uptake and innate immunity

    PubMed Central

    Higgins, Matthew K.; Tkachenko, Olga; Brown, Alan; Reed, Jenny; Raper, Jayne; Carrington, Mark

    2013-01-01

    African trypanosomes are protected by a densely packed surface monolayer of variant surface glycoprotein (VSG). A haptoglobin–hemoglobin receptor (HpHbR) within this VSG coat mediates heme acquisition. HpHbR is also exploited by the human host to mediate endocytosis of trypanolytic factor (TLF)1 from serum, contributing to innate immunity. Here, the crystal structure of HpHbR from Trypanosoma congolense has been solved, revealing an elongated three α-helical bundle with a small membrane distal head. To understand the receptor in the context of the VSG layer, the dimensions of Trypanosoma brucei HpHbR and VSG have been determined by small-angle X-ray scattering, revealing the receptor to be more elongated than VSG. It is, therefore, likely that the receptor protrudes above the VSG layer and unlikely that the VSG coat can prevent immunoglobulin binding to the receptor. The HpHb-binding site has been mapped by single-residue mutagenesis and surface plasmon resonance. This site is located where it is readily accessible above the VSG layer. A single HbHpR polymorphism unique to human infective T. brucei gambiense has been shown to be sufficient to reduce binding of both HpHb and TLF1, modulating ligand affinity in a delicate balancing act that allows nutrient acquisition but avoids TLF1 uptake. PMID:23319650

  8. Structure of the trypanosome haptoglobin-hemoglobin receptor and implications for nutrient uptake and innate immunity.

    PubMed

    Higgins, Matthew K; Tkachenko, Olga; Brown, Alan; Reed, Jenny; Raper, Jayne; Carrington, Mark

    2013-01-29

    African trypanosomes are protected by a densely packed surface monolayer of variant surface glycoprotein (VSG). A haptoglobin-hemoglobin receptor (HpHbR) within this VSG coat mediates heme acquisition. HpHbR is also exploited by the human host to mediate endocytosis of trypanolytic factor (TLF)1 from serum, contributing to innate immunity. Here, the crystal structure of HpHbR from Trypanosoma congolense has been solved, revealing an elongated three α-helical bundle with a small membrane distal head. To understand the receptor in the context of the VSG layer, the dimensions of Trypanosoma brucei HpHbR and VSG have been determined by small-angle X-ray scattering, revealing the receptor to be more elongated than VSG. It is, therefore, likely that the receptor protrudes above the VSG layer and unlikely that the VSG coat can prevent immunoglobulin binding to the receptor. The HpHb-binding site has been mapped by single-residue mutagenesis and surface plasmon resonance. This site is located where it is readily accessible above the VSG layer. A single HbHpR polymorphism unique to human infective T. brucei gambiense has been shown to be sufficient to reduce binding of both HpHb and TLF1, modulating ligand affinity in a delicate balancing act that allows nutrient acquisition but avoids TLF1 uptake.

  9. Ingestion of crude oil: effects on digesta retention times and nutrient uptake in captive river otters.

    PubMed

    Ormseth, O A; Ben-David, M

    2000-09-01

    Studies following the Exxon Valdez oil spill in Prince William Sound, Alaska indicated that river otters (Lontra canadensis) from oiled regions displayed symptoms of degraded health, including reduced body weight. We examined the fate of ingested oil in the digestive tract and its effects on gut function in captive river otters. Fifteen wild-caught males were assigned to three groups, two of which were given weathered crude oil in food (i.e., control, 5 ppm day(-1), and 50 ppm day(-1)) under controlled conditions at the Alaska Sealife Center. Using glass beads as non-specific digesta markers and stable isotope analysis, we determined the effects of ingested oil on retention time and nutrient uptake. Our data indicated that oil ingestion reduced marker retention time when we controlled for activity and meal size. Fecal isotope ratios suggested that absorption of lipids in the oiled otters might have been affected by reduced retention time of food. In addition, a dilution model indicated that as much as 80% of ingested oil was not absorbed in high-dose animals. Thus, while the ingestion of large quantities of weathered crude oil appears to reduce absorption of oil hydrocarbons and may alleviate systemic effects, it may concurrently affect body condition by impacting digestive function.

  10. Role of microbial inoculation and industrial by-product phosphogypsum in growth and nutrient uptake of maize (Zea mays L.) grown in calcareous soil.

    PubMed

    Al-Enazy, Abdul-Aziz R; Al-Oud, Saud S; Al-Barakah, Fahad N; Usman, Adel Ra

    2017-08-01

    Alkaline soils with high calcium carbonate and low organic matter are deficient in plant nutrient availability. Use of organic and bio-fertilizers has been suggested to improve their properties. Therefore, a greenhouse experiment was conducted to evaluate the integrative role of phosphogypsum (PG; added at 0.0, 10, 30, and 50 g PG kg(-1) ), cow manure (CM; added at 50 g kg(-1) ) and mixed microbial inoculation (Incl.; Azotobacter chroococcum, and phosphate-solubilizing bacteria Bacillus megaterium var. phosphaticum and Pseudomonas fluorescens) on growth and nutrients (N, P, K, Fe, Mn, Zn and Cu) uptake of maize (Zea mays L.) in calcareous soil. Treatment effects on soil chemical and biological properties and the Cd and Pb availability to maize plants were also investigated. Applying PG decreased soil pH. The soil available P increased when soil was inoculated and/or treated with CM, especially with PG. The total microbial count and dehydrogenase activity were enhanced with PG+CM+Incl. Inoculated soils treated with PG showed significant increases in NPK uptake and maize plant growth. However, the most investigated treatments showed significant decreases in shoot micronutrients. Cd and Pb were not detected in maize shoots. Applying PG with microbial inoculation improved macronutrient uptake and plant growth. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Impacts of industrial waste resources on maize (Zea mays L.) growth, yield, nutrients uptake and soil properties.

    PubMed

    Singh, Satnam; Young, Li-Sen; Shen, Fo-Ting; Young, Chiu-Chung

    2014-10-01

    Discharging untreated highly acidic (pH<4.0), organic and nutrients rich monosodium glutamate wastewater (MW), and highly alkaline (pH>10.0) paper-mill wastewater (PW) causes environmental pollution. When acidity of MW neutralized (pH 6.5±0.1) with PW and lime (treatments represented as MW+PW and MW+Lime), then MW may be utilized as a potential source of nutrients and organic carbon for sustainable food production. Objectives of this study were to compare the effects of PW and lime neutralized MW and chemical fertilizers on maize (Zea mays L. cv. Snow Jean) plant growth, yield, nutrients uptake, soil organic matter and humic substances. The field experiment was carried out on maize using MW at 6000 L ha(-1). Impacts of the MW application on maize crop and soil properties were evaluated at different stages. At harvest, plant height, and plant N and K uptake were higher in MW treatment. Leaf area index at 60 days after sowing, plant dry matter accumulation at harvest, and kernels ear(-1) and 100-kernel weight were higher in MW+Lime treatment. Kernel N, P, K, Mn, Fe and Zn, and plant Zn uptake were highest in MW+Lime. Plant Fe uptake, and soil organic matter and humic substances were highest in MW+PW. The MW+PW and MW+Lime treatments exhibited comparable results with chemically fertilized treatment. The MW acidity neutralized with lime showed positive impacts on growth, yield and nutrients uptake; nevertheless, when MW pH neutralized with PW has an additional benefit on increase in soil organic matter and humic substances. Copyright © 2014. Published by Elsevier Ltd.

  12. Effects of soil temperature on shoot and root growth and nutrient uptake of 5-year-old Norway spruce seedlings.

    PubMed

    Lahti, M; Aphalo, P J; Finér, L; Ryyppö, A; Lehto, T; Mannerkoski, H

    2005-01-01

    Soil temperature is a main factor limiting root growth in the boreal forest. To simulate the possible soil-warming effect of future climate change, 5-year-old Norway spruce (Picea abies (L.) Karst.) seedlings were subjected to three simulated growing seasons in controlled environment rooms. The seedlings were acclimated to a soil temperature of 16 degrees C during the first (GS I) and third growing seasons (GS III), but were assigned to random soil-temperature treatments of 9, 13, 18 and 21 degrees C during the second growing season (GS II). In GS II, shoot diameter growth was lowest in the 21 degrees C treatment and root growth was lowest in the 9 degrees C treatment. In GS III, shoot height and root length growth improved in seedlings that had been kept at 9 degrees C during GS II, indicating compensatory growth in response to increased soil temperature. The temporary decrease in soil temperature had no long-lasting significant effect on seedling biomass or total nutrient uptake. At the end of GS III, fine roots of seedlings exposed to a soil temperature of 21 degrees C in GS II were distributed more evenly between the organic and mineral soil layers than roots of seedlings in the other treatments. During GS II and GS III, root growth started earlier than shoot growth, decreased during the rapid shoot elongation phase and increased again as shoot growth decreased.

  13. Ammonium and nitrate uptake lengths in a small forested stream determined by {sup 15}N tracer and short-term nutrient enrichment experiments

    SciTech Connect

    Mulholland, P.J.; Tank, J.L.; Sanzone, D.M.; Webster, J.R.; Wollheim, W.; Peterson, B.J.; Meyer, J.L.

    1998-11-01

    Nutrient cycling is an important characteristic of all ecosystems, including streams. Nutrients often limit the growth rates of stream algae and heterotrophic microbes and the decomposition rate of allochthonous organic matter. Nutrient uptake (S{sub W}), defined as the mean distance traveled by a nutrient atom dissolved in stream water before uptake by biota is often used as an index of nutrient cycling in streams. It is often overlooked, however, that S{sub W} is not a measure of nutrient uptake rate per se, but rather a measure of the efficiency with which a stream utilizes the available nutrient supply. The ideal method for measuring S{sub W} involves short-term addition of a nutrient tracer. Regulatory constraints often preclude use of nutrient radiotracers in field studies and methodological difficulties and high analytical costs have previously hindered the use of stable isotope nutrient tracers (e.g., {sup 15}N). Short-term nutrient enrichments are an alternative to nutrient tracer additions for measuring S{sub W}.

  14. Uptake and partitioning of nutrients in blackberry and raspberry and evaluating plant nutrient status for accurate assessment of fertilizer requirements

    USDA-ARS?s Scientific Manuscript database

    Raspberry and blackberry plantings have relatively low nutrient requirements compared to many other perennial fruit crops. Annual total N accumulation in the aboveground plant ranged from 69-122 kg/ha and 37-44 kg/ha in field-grown red raspberry and blackberry. Primocanes rely primarily on fertilize...

  15. Uptake and partitioning of nutrients in blackberry and raspberry and evaluating plant nutrient status for accurate assessment of fertilizer requirements

    USDA-ARS?s Scientific Manuscript database

    Raspberry and blackberry plantings have a relatively low nutrient requirement compared to many other perennial fruit crops. Annual total N accumulation ranged from 62-110 lb/a in red raspberry and 33-39 lb/a in blackberry. Primocanes rely primarily on fertilizer N for growth, whereas floricane growt...

  16. Impact of variable bed morphology on transient storage, hyporhic exchange and nutrient uptake in a field-scale flume

    NASA Astrophysics Data System (ADS)

    Orr, C. H.; Clark, J. J.; Wilcock, P. R.; Finlay, J. C.; Doyle, M. W.

    2006-12-01

    As part of an ongoing, multidisciplinary experimental effort coordinated by the National Center for Earth-surface Dynamics we investigated reach-scale interactions between, bed morphology, transient storage, nutrient cycling in a field-scale flume supplied with water from the Mississippi River. A combination of conservative salt tracer and soluble reactive phosphorous and nitrate additions was used to study the effects on these parameters of two bed morphologies (plane bed and alternate bar) and two sediment mixtures (clean gravel and sandy gravel) to determine how differences in sediment size and between plane-bed and laterally variable morphologies influence spatial heterogeneity in transport and uptake of nutrients. The goal was to partitioning reach-scale transient storage values between surface storage and hyporheic flow, determine how these values and their relative importance changed as we varied bed texture (or permeability) and added or removed surface features, and to then measure uptake of biologically available nitrogen and phosphorus individually and together along these surface and subsurface flow paths. In a final phase of the experiment, lights were added to the flume to determine how benthic algal abundance may change bed permeability and solute exchange with the bed as well as nutrient uptake rates. Initial results show that while mean water residence time varied by a factor of 2 across treatments (14 - 30 min) phosphorus uptake rates varied widely (5.5-2500 μg * m-2 * min-1 and the addition of light had a stronger impact on uptake rates than changes in geomorphic form.

  17. Nutrient Uptake by Microorganisms according to Kinetic Parameters from Theory as Related to Cytoarchitecture

    PubMed Central

    Button, D. K.

    1998-01-01

    The abilities of organisms to sequester substrate are described by the two kinetic constants specific affinity, a°, and maximal velocity Vmax. Specific affinity is derived from the frequency of substrate-molecule collisions with permease sites on the cell surface at subsaturating concentrations of substrates. Vmax is derived from the number of permeases and the effective residence time, τ, of the transported molecule on the permease. The results may be analyzed with affinity plots (v/S versus v, where v is the rate of substrate uptake), which extrapolate to the specific affinity and are usually concave up. A third derived parameter, the affinity constant KA, is similar to KM but is compared to the specific affinity rather than Vmax  and is defined as the concentration of substrate necessary to reduce the specific affinity by half. It can be determined in the absence of a maximal velocity measurement and is equal to the Michaelis constant for a system with hyperbolic kinetics. Both are taken as a measure of τ, with departure of KM from KA being affected by permease/enzyme ratios. Compilation of kinetic data indicates a 108-fold range in specific affinities and a smaller (103-fold) range in Vmax values. Data suggest that both specific affinities and maximal velocities can be underestimated by protocols which interrupt nutrient flow prior to kinetic analysis. A previously reported inverse relationship between specific affinity and saturation constants was confirmed. Comparisons of affinities with ambient concentrations of substrates indicated that only the largest a°S values are compatible with growth in natural systems. PMID:9729603

  18. Effects of cadmium on uptake and translocation of nutrient elements in different welsh onion (Allium fistulosum L.) cultivars.

    PubMed

    Li, Xuhui; Zhou, Qixing; Sun, Xiaoyin; Ren, Wenjie

    2016-03-01

    The concentration of nutrient elements is an important quality characteristic of vegetables, and the variation in accumulation among cultivars can provide clues about the mechanism of low accumulation of heavy metals. Pot-culture experiments were arranged under four cadmium (Cd) treatments (CK, 1.0, 2.5 and 5.0mg/kg) to explore influences of Cd on the accumulation of nutrient elements in 25 welsh onion cultivars. There were significant positive correlations (p<0.05) between Cd and nutrient elements in the pseudostems and leaves. There were also significant positive correlations in nutrient elements (p<0.05) among cultivars, which might be disturbed under high Cd treatments, especially for P, Fe and Mn. Our results suggested that there is a synergistic effect on the accumulation between Cd and nutrient elements, and within nutrient elements among cultivars. In addition the uptake and translocation process of Cd was closely related to Mn in welsh onion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Arbuscular mycorrhizas enhance nutrient uptake in different wheat genotypes at high salinity levels under field and greenhouse conditions.

    PubMed

    Mardukhi, Baran; Rejali, Farhad; Daei, Gudarz; Ardakani, Mohammad Reza; Malakouti, Mohammad Javad; Miransari, Mohammad

    2011-07-01

    Since most experiments regarding the symbiosis between arbuscular mycorrhizal (AM) fungi and their host plants under salinity stress have been performed only under greenhouse conditions, this research work was also conducted under field conditions. The effects of three AM species including Glomus mosseae, G. etunicatum and G. intraradices on the nutrient uptake of different wheat cultivars (including Roshan, Kavir and Tabasi) under field and greenhouse (including Chamran and Line 9) conditions were determined. At field harvest, the concentrations of N, Ca, Mg, Fe, Cu, and Mn, and at greenhouse harvest, plant growth, root colonization and concentrations of different nutrients including N, K, P, Ca, Mg, Mn, Cu, Fe, Zn, Na and Cl were determined. The effects of wheat cultivars on the concentrations of N, Ca, and Mn, and of all nutrients were significant at field and greenhouse conditions, respectively. In both experiments, AM fungi significantly enhanced the concentrations of all nutrients including N, K, P, Ca, Mg, Mn, Cu, Fe, Zn, Na and Cl. The synergistic and enhancing effects of co-inoculation of AM species on plant growth and the inhibiting effect of AM species on Na(+) rather than on Cl(-) uptake under salinity are also among the important findings of this research work. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  20. Mycorrhiza and heavy metal resistant bacteria enhance growth, nutrient uptake and alter metabolic profile of sorghum grown in marginal soil.

    PubMed

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2016-08-01

    The main challenge for plants growing in nutrient poor, contaminated soil is biomass reduction, nutrient deficiency and presence of heavy metals. Our aim is to overcome these challenges using different microbial combinations in mining-impacted soil and focus on their physiological and biochemical impacts on a model plant system, which has multiple applications. In the current study, sorghum BTx623 seedlings grown in mining-impacted soil in greenhouse were subjected to plant growth promoting bacteria (PGPB or B) alone, PGPB with arbuscular mycorrhizal fungi (My), My alone and control group with no treatment. Root biomass and uptake of most of the elements showed significant increase in all treatment groups in comparison with control. Mycorrhiza group showed the best effect followed by My + B and B groups for uptake of majority of the elements by roots. On the contrary, biomass of both shoot and root was more influenced by B treatment than My + B and My treatments. Metabolomics identified compounds whose levels changed in roots of treatment groups significantly in comparison to control. Upregulation of stearic acid, sorbitol, sebacic acid and ferulic acid correlated positively with biomass and uptake of almost all elements. Two biochemical pathways, fatty acid biosynthesis and galactose metabolism, were regulated in all treatment groups. Three common pathways were upregulated only in My and My + B groups. Our results suggest that PGPB enhanced metabolic activities which resulted in increase in element uptake and sorghum root biomass whether accompanied with mycorrhiza or used solely.

  1. Complementarity in root architecture for nutrient uptake in ancient maize/bean and maize/bean/squash polycultures.

    PubMed

    Postma, Johannes A; Lynch, Jonathan P

    2012-07-01

    During their domestication, maize, bean and squash evolved in polycultures grown by small-scale farmers in the Americas. Polycultures often overyield on low-fertility soils, which are a primary production constraint in low-input agriculture. We hypothesized that root architectural differences among these crops causes niche complementarity and thereby greater nutrient acquisition than corresponding monocultures. A functional-structural plant model, SimRoot, was used to simulate the first 40 d of growth of these crops in monoculture and polyculture and to determine the effects of root competition on nutrient uptake and biomass production of each plant on low-nitrogen, -phosphorus and -potassium soils. Squash, the earliest domesticated crop, was most sensitive to low soil fertility, while bean, the most recently domesticated crop, was least sensitive to low soil fertility. Nitrate uptake and biomass production were up to 7 % greater in the polycultures than in the monocultures, but only when root architecture was taken into account. Enhanced nitrogen capture in polycultures was independent of nitrogen fixation by bean. Root competition had negligible effects on phosphorus or potassium uptake or biomass production. We conclude that spatial niche differentiation caused by differences in root architecture allows polycultures to overyield when plants are competing for mobile soil resources. However, direct competition for immobile resources might be negligible in agricultural systems. Interspecies root spacing may also be too large to allow maize to benefit from root exudates of bean or squash. Above-ground competition for light, however, may have strong feedbacks on root foraging for immobile nutrients, which may increase cereal growth more than it will decrease the growth of the other crops. We note that the order of domestication of crops correlates with increasing nutrient efficiency, rather than production potential.

  2. Complementarity in root architecture for nutrient uptake in ancient maize/bean and maize/bean/squash polycultures

    PubMed Central

    Postma, Johannes A.; Lynch, Jonathan P.

    2012-01-01

    Background and Aims During their domestication, maize, bean and squash evolved in polycultures grown by small-scale farmers in the Americas. Polycultures often overyield on low-fertility soils, which are a primary production constraint in low-input agriculture. We hypothesized that root architectural differences among these crops causes niche complementarity and thereby greater nutrient acquisition than corresponding monocultures. Methods A functional–structural plant model, SimRoot, was used to simulate the first 40 d of growth of these crops in monoculture and polyculture and to determine the effects of root competition on nutrient uptake and biomass production of each plant on low-nitrogen, -phosphorus and -potassium soils. Key Results Squash, the earliest domesticated crop, was most sensitive to low soil fertility, while bean, the most recently domesticated crop, was least sensitive to low soil fertility. Nitrate uptake and biomass production were up to 7 % greater in the polycultures than in the monocultures, but only when root architecture was taken into account. Enhanced nitrogen capture in polycultures was independent of nitrogen fixation by bean. Root competition had negligible effects on phosphorus or potassium uptake or biomass production. Conclusions We conclude that spatial niche differentiation caused by differences in root architecture allows polycultures to overyield when plants are competing for mobile soil resources. However, direct competition for immobile resources might be negligible in agricultural systems. Interspecies root spacing may also be too large to allow maize to benefit from root exudates of bean or squash. Above-ground competition for light, however, may have strong feedbacks on root foraging for immobile nutrients, which may increase cereal growth more than it will decrease the growth of the other crops. We note that the order of domestication of crops correlates with increasing nutrient efficiency, rather than production

  3. Improving the uptake of pulmonary rehabilitation in patients with COPD:

    PubMed Central

    Harris, David; Hayter, Mark; Allender, Steven

    2008-01-01

    Background Pulmonary rehabilitation can improve the quality of life and ability to function of patients with chronic obstructive pulmonary disease (COPD). It may also reduce hospital admission and inpatient stay with exacerbations of COPD. Some patients who are eligible for pulmonary rehabilitation may not accept an offer of it, thereby missing an opportunity to improve their health status. Aim To identify a strategy for improving the uptake of pulmonary rehabilitation. Design of study Qualitative interviews with patients. Setting Patients with COPD were recruited from a suburban general practice in north-east Derbyshire, UK. Method In-depth interviews were conducted on a purposive sample of 16 patients with COPD to assess their concerns about accepting an offer of pulmonary rehabilitation. Interviews were analysed using grounded theory. Results Fear of breathlessness and exercise, and the effect of pulmonary rehabilitation on coexisting medical problems were the most common concerns patients had about taking part in the rehabilitation. The possibility of reducing the sensation of breathlessness and regaining the ability to do things, such as play with their grandchildren, were motivators to participating. Conclusion A model is proposed where patients who feel a loss of control as their disease advances may find that pulmonary rehabilitation offers them the opportunity to regain control. Acknowledging patients' fears and framing pulmonary rehabilitation as a way of ‘regaining control’ may improve patient uptake. PMID:18826782

  4. Improved Tumor Uptake by Optimizing Liposome Based RES Blockade Strategy

    PubMed Central

    Sun, Xiaolian; Yan, Xuefeng; Jacobson, Orit; Sun, Wenjing; Wang, Zhantong; Tong, Xiao; Xia, Yuqiong; Ling, Daishun; Chen, Xiaoyuan

    2017-01-01

    Minimizing the sequestration of nanomaterials (NMs) by the reticuloendothelial system (RES) can enhance the circulation time of NMs, and thus increase their tumor-specific accumulation. Liposomes are generally regarded as safe (GRAS) agents that can block the RES reversibly and temporarily. With the help of positron emission tomography (PET), we monitored the in vivo tissue distribution of 64Cu-labeled 40 × 10 nm gold nanorods (Au NRs) after pretreatment with liposomes. We systematically studied the effectiveness of liposome administration by comparing (1) differently charged liposomes; (2) different liposome doses; and (3) varying time intervals between liposome dose and NR dose. By pre-injecting 400 μmol/kg positively charged liposomes into mice 5 h before the Au NRs, the liver and spleen uptakes of Au NRs decreased by 30% and 53%, respectively. Significantly, U87MG tumor uptake of Au NRs increased from 11.5 ± 1.1 %ID/g to 16.1 ± 1.3 %ID/g at 27 h post-injection. Quantitative PET imaging is a valuable tool to understand the fate of NMs in vivo and cationic liposomal pretreatment is a viable approach to reduce RES clearance, prolong circulation, and improve tumor uptake. PMID:28042337

  5. An essential dual-function complex mediates erythrocyte invasion and channel-mediated nutrient uptake in malaria parasites

    PubMed Central

    Ito, Daisuke; Schureck, Marc A; Desai, Sanjay A

    2017-01-01

    Malaria parasites evade immune detection by growth and replication within erythrocytes. After erythrocyte invasion, the intracellular pathogen must increase host cell uptake of nutrients from plasma. Here, we report that the parasite-encoded RhopH complex contributes to both invasion and channel-mediated nutrient uptake. As rhoph2 and rhoph3 gene knockouts were not viable in the human P. falciparum pathogen, we used conditional knockdowns to determine that the encoded proteins are essential and to identify their stage-specific functions. We exclude presumed roles for RhopH2 and CLAG3 in erythrocyte invasion but implicate a RhopH3 contribution either through ligand-receptor interactions or subsequent parasite internalization. These proteins then traffic via an export translocon to the host membrane, where they form a nutrient channel. Knockdown of either RhopH2 or RhopH3 disrupts the entire complex, interfering with organellar targeting and subsequent trafficking. Therapies targeting this complex should attack the pathogen at two critical points in its cycle. DOI: http://dx.doi.org/10.7554/eLife.23485.001 PMID:28221136

  6. Modeling the carbon cost of plant nitrogen acquisition: Mycorrhizal trade-offs and multipath resistance uptake improve predictions of retranslocation

    NASA Astrophysics Data System (ADS)

    Brzostek, Edward R.; Fisher, Joshua B.; Phillips, Richard P.

    2014-08-01

    Accurate projections of the future land carbon (C) sink by terrestrial biosphere models depend on how nutrient constraints on net primary production are represented. While nutrient limitation is nearly universal, current models do not have a C cost for plant nutrient acquisition. Also missing are symbiotic mycorrhizal fungi, which can consume up to 20% of net primary production and supply up to 50% of a plant's nitrogen (N) uptake. Here we integrate simultaneous uptake and mycorrhizae into a cutting-edge plant N model—Fixation and Uptake of Nitrogen (FUN)—that can be coupled into terrestrial biosphere models. The C cost of N acquisition varies as a function of mycorrhizal type, with plants that support arbuscular mycorrhizae benefiting when N is relatively abundant and plants that support ectomycorrhizae benefiting when N is strongly limiting. Across six temperate forested sites (representing arbuscular mycorrhizal- and ectomycorrhizal-dominated stands and 176 site years), including multipath resistance improved the partitioning of N uptake between aboveground and belowground sources. Integrating mycorrhizae led to further improvements in predictions of N uptake from soil (R2 = 0.69 increased to R2 = 0.96) and from senescing leaves (R2 = 0.29 increased to R2 = 0.73) relative to the original model. On average, 5% and 9% of net primary production in arbuscular mycorrhizal- and ectomycorrhizal-dominated forests, respectively, was needed to support mycorrhizal-mediated acquisition of N. To the extent that resource constraints to net primary production are governed by similar trade-offs across all terrestrial ecosystems, integrating these improvements to FUN into terrestrial biosphere models should enhance predictions of the future land C sink.

  7. Harmful algal blooms and eutrophication: "strategies" for nutrient uptake and growth outside the Redfield comfort zone

    NASA Astrophysics Data System (ADS)

    Glibert, Patricia M.; Burkholder, Joann M.

    2011-07-01

    While many harmful algal blooms have been associated with increasing eutrophication, not all species respond similarly and the increasing challenge, especially for resource managers, is to determine which blooms are related to eutrophication and to understand why particular species proliferate under specific nutrient conditions. The overall goal of this brief review is to describe why nutrient loads are not changing in stoichiometric proportion to the "Redfield ratio", and why this has important consequences for algal growth. Many types of harmful algae appear to be able to thrive, and/or increase their production of toxins, when nutrient loads are not in proportion classically identified as Redfield ratios. Here we also describe some of the physiological mechanisms of different species to take up nutrients and to thrive under conditions of nutrient imbalance.

  8. Silicon uptake by sponges: a twist to understanding nutrient cycling on continental margins.

    PubMed

    Maldonado, Manuel; Navarro, Laura; Grasa, Ana; Gonzalez, Alicia; Vaquerizo, Isabel

    2011-01-01

    About 75% of extant sponge species use dissolved silicon (DSi) to build a siliceous skeleton. We show that silicon (Si) uptake by sublittoral Axinella demosponges follows an enzymatic kinetics. Interestingly, maximum uptake efficiency occurs at experimental DSi concentrations two orders of magnitude higher than those in the sponge habitats, being unachievable in coastal waters of modern oceans. Such uptake performance appears to be rooted in a former condition suitable to operate at the seemingly high DSi values characterizing the pre-Tertiary (>65 mya) habitats where this sponge lineage diversified. Persistence of ancestral uptake systems causes sponges to be outcompeted by the more efficient uptake of diatoms at the low ambient DSi levels characterizing Recent oceans. Yet, we show that sublittoral sponges consume substantial coastal DSi (0.01-0.90 mmol Si m(-2) day(-1)) at the expenses of the primary-production circuit. Neglect of that consumption hampers accurate understanding of Si cycling on continental margins.

  9. Compost and crude humic substances produced from selected wastes and their effects on Zea mays L. nutrient uptake and growth.

    PubMed

    Palanivell, Perumal; Susilawati, Kasim; Ahmed, Osumanu Haruna; Majid, Nik Muhamad

    2013-01-01

    Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation.

  10. Compost and Crude Humic Substances Produced from Selected Wastes and Their Effects on Zea mays L. Nutrient Uptake and Growth

    PubMed Central

    Palanivell, Perumal; Susilawati, Kasim; Ahmed, Osumanu Haruna; Majid, Nik Muhamad

    2013-01-01

    Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation. PMID:24319353

  11. Effects of different fertilizers on growth and nutrient uptake of Lolium multiflorum grown in Cd-contaminated soils.

    PubMed

    Liu, Mohan; Li, Yang; Che, Yeye; Deng, Shaojun; Xiao, Yan

    2017-08-25

    This study aimed to explore the effects of different fertilizers and their combinations on growth and nutrient and Cd uptake of Lolium multiflorum. Compared with control treatment, chemical fertilizer, organic manure, and their conjunctions with biofertilizer increased shoot biomass. Biofertilizers were found to cause significant reductions in shoot biomass of plants grown in organic manure-treated and control soil. Decreased soil-available N and P and shoot N and K concentrations in biofertilizer amendment treatments indicated that plant growth and nutrient absorption might be negatively affected under nutrient deficiency conditions. Elevated shoot biomasses contributed to the highest shoot Cd contents in chemical fertilizer and chemical fertilizer + biofertilizer treatments among all treatments. But the maximum translocation efficiency occurred in biofertilizer + chemical fertilizer + organic manure treatment, followed by organic manure and chemical fertilizer + organic manure treatments. Based on the results, we can conclude that the application of only the biofertilizer Bacillus subtilis should be avoided in nutrient-limited soils. Chemical fertilizer application could benefit the amount of Cd in shoots, and organic manure application and its combinations could result in the higher translocation efficiency.

  12. Golgi N-glycan branching N-acetylglucosaminyltransferases I, V and VI promote nutrient uptake and metabolism

    PubMed Central

    Abdel Rahman, Anas M; Ryczko, Michael; Nakano, Miyako; Pawling, Judy; Rodrigues, Tania; Johswich, Anita; Taniguchi, Naoyuki; Dennis, James W

    2015-01-01

    Nutrient transporters are critical gate-keepers of extracellular metabolite entry into the cell. As integral membrane proteins, most transporters are N-glycosylated, and the N-glycans are remodeled in the Golgi apparatus. The Golgi branching enzymes N-acetylglucosaminyltransferases I, II, IV, V and avian VI (encoded by Mgat1, Mgat2, Mgat4a/b/c Mgat5 and Mgat6), each catalyze the addition of N-acetylglucosamine (GlcNAc) in N-glycans. Here, we asked whether N-glycan branching promotes nutrient transport and metabolism in immortal human HeLa carcinoma and non-malignant HEK293 embryonic kidney cells. Mgat6 is absent in mammals, but ectopic expression can be expected to add an additional β1,4-linked branch to N-glycans, and may provide evidence for functional redundancy of the N-glycan branches. Tetracycline (tet)-induced overexpression of Mgat1, Mgat5 and Mgat6 resulted in increased enzyme activity and increased N-glycan branching concordant with the known specificities of these enzymes. Tet-induced Mgat1, Mgat5 and Mgat6 combined with stimulation of hexosamine biosynthesis pathway (HBP) to UDP-GlcNAc, increased cellular metabolite levels, lactate and oxidative metabolism in an additive manner. We then tested the hypothesis that N-glycan branching alone might promote nutrient uptake when glucose (Glc) and glutamine are limiting. In low glutamine and Glc medium, tet-induced Mgat5 alone increased amino acids uptake, intracellular levels of glycolytic and TCA intermediates, as well as HEK293 cell growth. More specifically, tet-induced Mgat5 and HBP elevated the import rate of glutamine, although transport of other metabolites may be regulated in parallel. Our results suggest that N-glycan branching cooperates with HBP to regulate metabolite import in a cell autonomous manner, and can enhance cell growth in low-nutrient environments. PMID:25395405

  13. Comparable light stimulation of organic nutrient uptake by SAR11 and Prochlorococcus in the North Atlantic subtropical gyre.

    PubMed

    Gómez-Pereira, Paola R; Hartmann, Manuela; Grob, Carolina; Tarran, Glen A; Martin, Adrian P; Fuchs, Bernhard M; Scanlan, David J; Zubkov, Mikhail V

    2013-03-01

    Subtropical oceanic gyres are the most extensive biomes on Earth where SAR11 and Prochlorococcus bacterioplankton numerically dominate the surface waters depleted in inorganic macronutrients as well as in dissolved organic matter. In such nutrient poor conditions bacterioplankton could become photoheterotrophic, that is, potentially enhance uptake of scarce organic molecules using the available solar radiation to energise appropriate transport systems. Here, we assessed the photoheterotrophy of the key microbial taxa in the North Atlantic oligotrophic gyre and adjacent regions using (33)P-ATP, (3)H-ATP and (35)S-methionine tracers. Light-stimulated uptake of these substrates was assessed in two dominant bacterioplankton groups discriminated by flow cytometric sorting of tracer-labelled cells and identified using catalysed reporter deposition fluorescence in situ hybridisation. One group of cells, encompassing 48% of all bacterioplankton, were identified as members of the SAR11 clade, whereas the other group (24% of all bacterioplankton) was Prochlorococcus. When exposed to light, SAR11 cells took 31% more ATP and 32% more methionine, whereas the Prochlorococcus cells took 33% more ATP and 34% more methionine. Other bacterioplankton did not demonstrate light stimulation. Thus, the SAR11 and Prochlorococcus groups, with distinctly different light-harvesting mechanisms, used light equally to enhance, by approximately one-third, the uptake of different types of organic molecules. Our findings indicate the significance of light-driven uptake of essential organic nutrients by the dominant bacterioplankton groups in the surface waters of one of the less productive, vast regions of the world's oceans-the oligotrophic North Atlantic subtropical gyre.

  14. Plant aquaporins: new perspectives on water and nutrient uptake in saline environment.

    PubMed

    del Martínez-Ballesta, M C; Silva, C; López-Berenguer, C; Cabañero, F J; Carvajal, M

    2006-09-01

    The mechanisms of salt stress and tolerance have been targets for genetic engineering, focusing on ion transport and compartmentation, synthesis of compatible solutes (osmolytes and osmoprotectants) and oxidative protection. In this review, we consider the integrated response to salinity with respect to water uptake, involving aquaporin functionality. Therefore, we have concentrated on how salinity can be alleviated, in part, if a perfect knowledge of water uptake and transport for each particular crop and set of conditions is available.

  15. Duodenal nutrient exclusion improves metabolic syndrome and stimulates villus hyperplasia

    PubMed Central

    Habegger, Kirk M; Al-Massadi, Omar; Heppner, Kristy M; Myronovych, Andriy; Holland, Jenna; Berger, Jose; Yi, Chun-Xia; Gao, Yuanging; Lehti, Maarit; Ottaway, Nickki; Amburgy, Sarah; Raver, Christine; Müller, Timo D; Pfluger, Paul T; Kohli, Rohit; Perez-Tilve, Diego; Seeley, Randy J; Tschöp, Matthias H

    2014-01-01

    Objective Surgical interventions that prevent nutrient exposure to the duodenum are among the most successful treatments for obesity and diabetes. However, these interventions are highly invasive, irreversible and often carry significant risk. The duodenal-endoluminal sleeve (DES) is a flexible tube that acts as a barrier to nutrient-tissue interaction along the duodenum. We implanted this device in Zucker Diabetic Fatty (ZDF) rats to gain greater understanding of duodenal nutrient exclusion on glucose homeostasis. Design ZDF rats were randomised to four groups: Naive, sham ad libitum, sham pair-fed, and DES implanted. Food intake, body weight (BW) and body composition were measured for 28 days postoperatively. Glucose, lipid and bile acid metabolism were evaluated, as well as histological assessment of the upper intestine. Results DES implantation induced a sustained decrease in BW throughout the study that was matched by pair-fed sham animals. Decreased BW resulted from loss of fat, but not lean mass. DES rats were also found to be more glucose tolerant than either ad libitum-fed or pair-fed sham controls, suggesting fat mass independent metabolic benefits. DES also reduced circulating triglyceride and glycerol levels while increasing circulating bile acids. Interestingly, DES stimulated a considerable increase in villus length throughout the upper intestine, which may contribute to metabolic improvements. Conclusions Our preclinical results validate DES as a promising therapeutic approach to diabetes and obesity, which offers reversibility, low risk, low invasiveness and triple benefits including fat mass loss, glucose and lipid metabolism improvement which mechanistically may involve increased villus growth in the upper gut. PMID:24107591

  16. Effects of nitrogen fertilization on soil nutrient concentration and phosphatase activity and forage nutrient uptake from a grazed pasture system.

    PubMed

    Dillard, Sandra Leanne; Wood, Charles Wesley; Wood, Brenda Hall; Feng, Yucheng; Owsley, Walter Frank; Muntifering, Russell Brian

    2015-05-01

    Over a 3-year period, the effect of differing N-application regimes on soil extractable-P concentration, soil phosphatase activity, and forage P uptake in a P-enriched grazed-pasture system was investigated. In the fall of each year, six 0.28-ha plots were overseeded with triticale ( × Triticosecale rimpaui Wittm.) and crimson clover (Trifolium incarnatum) into a tall fescue (Lolium arundinacea)/bermudagrass (Cynodon dactylon) sod and assigned to 1 of 3 N-fertilizer treatments (n = 2): 100% of N recommendation in a split application (100N), 50% in a single application (50N), and 0% of N recommendation (0N) for triticale. Cattle commenced grazing the following spring and grazed until May. In the summer, plots were overseeded with cowpea (Vigna unguiculata), fertilized at the same rates by reference to N recommendations for bermudagrass, and grazed by cattle until September. There were no effects of N fertilization on soil phosphatase activity, electrical conductivity, or concentrations of water-soluble P. Concentrations of extractable P decreased in plots receiving 50N, but increasing N fertilization to 100N resulted in no further reduction in extractable P. Forage biomass, foliar P concentrations, and forage P mass were not affected by N fertilization rates at the plant-community level, but responses were observed within individual forage species. Results are interpreted to mean that N fertilization at 50% of the agronomic recommendation for the grass component can increase forage P mass of specific forages and decrease soil extractable P, thus providing opportunity for decreasing P losses from grazed pasture.

  17. Comparing Measures of Fine Root Uptake by Mature Trees: Applications for Determining the Potential Impacts of Climate Change-Induced Soil Freezing on Nutrient Uptake by Sugar Maple and Red Spruce

    NASA Astrophysics Data System (ADS)

    Socci, A. M.; Templer, P. H.

    2008-12-01

    Forests of the northeastern United States are predicted to experience a decrease in the depth and duration of snow pack due to global climate change. Even when coupled with milder winter temperatures, the loss of forest floor insulation can increase soil freezing depth and duration during the winter months. Soil frost leads to increased root mortality and soil nitrate leaching in stands dominated by sugar maple, a dominant tree species of northern hardwood forests. Greater nitrogen losses may be due to reduced nitrogen uptake by plant roots. As nitrogen is an essential nutrient for trees, changes in nitrogen uptake by fine roots may have implications for forest productivity and carbon storage. To test the impact of increased soil freezing on fine root uptake of nutrients from the soil, we established a snow removal experiment in sugar maple and red spruce dominated forests at the Hubbard Brook Experimental Forest in New Hampshire, USA. In the first year of this study, we measured uptake of ammonium (NH4+) and nitrate (NO3-) by fine roots of sugar maple and red spruce during the early (May), peak (July), and late (September) growing season. Individuals of sugar maple were located on paired plots (n=4 reference and snow-removal plots, n= 3 individuals per plot) and sampled for rates of nutrient uptake prior to snow removal. We used both an in situ intact root uptake measurement known as "nitrogen depletion", and an ex situ excised root measurement. Individuals of red spruce (n=1 reference and snow-removal plot, n=3 individuals per plot) were sampled after one winter of snow removal, also using one in situ and one ex situ method of measuring fine root uptake of nutrients. Individuals of sugar maple took up significantly more NH4+ than NO3- during the early growing season, but there was no significant difference between forms of nitrogen taken up during the peak growing season. Individuals of red spruce took up significantly more NH4+ than NO3- during both the early

  18. The effect of modifying rooting depths and nitrification inhibitors on nutrient uptake from organic biogas residues in maize

    NASA Astrophysics Data System (ADS)

    Dietrich, Charlotte C.; Koller, Robert; Nagel, Kerstin A.; Schickling, Anke; Schrey, Silvia D.; Jablonowski, Nicolai D.

    2017-04-01

    Optimizing the application of and nutrient uptake from organic nutrient sources, such as the nutrient-rich residues ("digestates") from the biogas industry, is becoming a viable option in remediating fertility on previously unsuitable soils for agricultural utilization. Proposedly, concurrent changes in root system architecture and functioning could also serve as the basis of future phytomining approaches. Herein, we evaluate the effect of spatial nutrient availability and nitrification on maize root architecture and nutrient uptake. We test these effects by applying maize-based digestate at a rate of 170 kg/ha in layers of varying depths (10, 25 and 40 cm) and through either the presence or absence of nitrification inhibitors. In order to regularly monitor above- and below-ground plant biomass production, we used the noninvasive phenotyping platform, GROWSCREEN-Rhizo at the Forschungszentrum Jülich, using rhizotrons (Nagel et al., 2012). Measured parameters included projected plant height and leaf area, as well as root length and spatial distribution. Additionally, root diameters were quantified after the destructive harvest, 21 days after sowing (DAS). Spatial nutrient availability significantly affected root system architecture, as for example root system size -the area occupied by roots- increased alongside nutrient layer depths. Fertilization also positively affected root length density (RLD). Within fertilized layers, the presence of nitrification inhibitors increased RLD by up to 30% and was most pronounced in the fine root biomass fraction (0.1 to 0.5mm). Generally, nitrification inhibitors promoted early plant growth by up to 45% across treatments. However, their effect varied in dependence of layer depths, leading to a time-delayed response in deeper layers, accounting for plants having to grow significantly longer roots in order to reach fertilized substrate. Nitrification inhibitors also initiated the comparatively early on-set of growth differences in

  19. Enhancement of growth and nutrient uptake of rapeseed (Brassica napus L.) by applying mineral nutrients and biofertilizers.

    PubMed

    Yasari, Esmaeil; Azadgoleh, M A Esmaeili; Mozafari, Saedeh; Alashti, Mahsa Rafati

    2009-01-15

    For investigating the effect of chemical fertilizer as well as biofertilizers on seed yield and quality i.e. oil, protein and nutrients concentration of rapeseed (Brassica napus L.), a split-plot fertilizers application experimental design in 4 replications was carried out during the 2005-2006 growing season, at the Gharakheil Agricultural Research Station in the Mazandaran province of Iran. Rapeseed was grown as a second crop in rotation after rice. Biofertilizers treatments were two different levels: control (no seed inoculation) and seeds inoculation with a combination of Azotobacter chroococcum and Azosprillum brasilense and Azosprillum lipoferum, as main plot and chemical fertilizers comprised N, P, K and their combinations, NPKS and NPK Zn as sub plots. The maximum value of seed yield obtained at (BF+NPK Zn) 3421.2 kg h(-1) corresponding to 244.5 pods per plant and maximum concentration of Zn in leaves as well as seeds. The highest weight of 1000 seeds (4.45 g) happened to obtain at (BF+NPK S) which coinciding with the maximum K levels in leaves. The highest number of branches was obtained at (BF+NPK Zn) with 4.43 branches per plant i.e., 46.2% increase over the control. The maximum value of rapeseed oil content 47.73% obtained at T16 (BF+NK) but maximum protein concentration of seed obtained at T12 (BF+N). Overall the results indicated that inoculation resulted in increase in seeds yield (21.17%), number of pods per plant (16.05%), number of branches (11.78%), weight of 1000 grain (2.92%), oil content of seeds (1.73%) and protein (3.91%) but decrease (-0.24%) in number of seeds per pods comparing to non-Biofertilizers treatments. Irrespective to the treatments, results showed that application of Biofertilizers coincided with 3.86, 0.82, 2.25, 0.75 and 0.91% increase in concentrations of N, P, K, S and Zn in the seeds over the non-Biofertilizers treatments.

  20. Uptake of inorganic and organic nutrient species during cultivation of a Chlorella isolate in anaerobically digested dairy waste.

    PubMed

    Wahal, Shantanu; Viamajala, Sridhar

    2016-09-01

    A natural assemblage of microalgae from a facultative lagoon system treating municipal wastewater was enriched for growth in the effluents of an anaerobic digester processing dairy waste. A green microalga with close resemblance to Chlorella sp. was found to be dominant after multiple cycles of sub-culturing. Subsequently, the strain (designated as LLAI) was isolated and cultivated in 20× diluted digester effluents under various incident light intensities (255-1,100 µmoles m(-2) s(-1) ) to systematically assess growth and nutrient utilization. Our results showed that LLAI production increased with increasing incident light and a maximum productivity of 0.34 g L(-1) d(-1) was attained when the incident irradiance was 1,100 µmoles m(-2) s(-1) . Lack of growth in the absence of light indicated that the cultures did not grow heterotrophically on the organic compounds present in the medium. However, the cultures were able to uptake organic N and P under phototrophic conditions and our calculations suggest that the carbon associated with these organic nutrients contributed significantly to the production of biomass. Overall, under high light conditions, LLAI cultures utilized half of the soluble organic nitrogen and >90% of the ammonium, orthophosphate, and dissolved organic phosphorus present in the diluted waste. Strain LLAI was also found to accumulate triacylglycerides (TAG) even before the onset of nutrient limitation and a lipid productivity of 37 mg-TAG L(-1) d(-1) was measured in cultures incubated at an incident irradiance of 1,100 µmoles m(-2) s(-1) . The results of this study suggest that microalgae isolates from natural environments are well-suited for nutrient remediation and biomass production from wastewater containing diverse inorganic and organic nutrient species. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1336-1342, 2016. © 2016 American Institute of Chemical Engineers.

  1. Growth, morphology, ammonium uptake and nutrient allocation of Myriophyllum brasiliense Cambess. under high NH₄⁺ concentrations.

    PubMed

    Saunkaew, Piyanart; Wangpakapattanawong, Prasit; Jampeetong, Arunothai

    2011-11-01

    The effects of high NH(4)(+) concentration on growth, morphology, NH(4) (+) uptake and nutrient allocation of Myriophyllum brasiliense were investigated in hydroponic culture. The plants were grown under greenhouse conditions for 4 weeks using four levels of NH(4)(+) concentration: 1, 5, 10 and 15 mM. M. brasiliense grew well with a relative growth rate of c.0.03 day(-1) at NH(4)(+) concentration up to 5 mM. At the higher NH(4)(+) concentrations the growth of the plants was stunted and the plants had short roots and few new buds, especially when grown in 15 mM NH(4)(+) where the submerged leaves were lost and there were rotten roots and submerged stems. To avoid NH(4)(+) toxicity, the plants may have a mechanism to prevent cytoplasmic NH(4)(+) accumulation in plant cells. The net uptake of NH(4)(+) significantly decreased and the total N significantly increased in the plants treated with 10 and 15 mM NH(4)(+), respectively. The plant may employ NH(4)(+) assimilation and extrusion as a mechanism to compensate for the high NH(4)(+) concentrations. However, the plants may show nutrient deficiency symptoms, especially K deficiency symptoms, after they were exposed to NH(4)(+) concentration higher than 10 mM. The present study provides a basic ecophysiology of M. brasiliense that it can grow in NH(4)(+) enriched water up to concentrations as high as 5 mM.

  2. Silicon uptake by sponges: a twist to understanding nutrient cycling on continental margins

    PubMed Central

    Maldonado, Manuel; Navarro, Laura; Grasa, Ana; Gonzalez, Alicia; Vaquerizo, Isabel

    2011-01-01

    About 75% of extant sponge species use dissolved silicon (DSi) to build a siliceous skeleton. We show that silicon (Si) uptake by sublittoral Axinella demosponges follows an enzymatic kinetics. Interestingly, maximum uptake efficiency occurs at experimental DSi concentrations two orders of magnitude higher than those in the sponge habitats, being unachievable in coastal waters of modern oceans. Such uptake performance appears to be rooted in a former condition suitable to operate at the seemingly high DSi values characterizing the pre-Tertiary (>65 mya) habitats where this sponge lineage diversified. Persistence of ancestral uptake systems causes sponges to be outcompeted by the more efficient uptake of diatoms at the low ambient DSi levels characterizing Recent oceans. Yet, we show that sublittoral sponges consume substantial coastal DSi (0.01–0.90 mmol Si m−2 day−1) at the expenses of the primary-production circuit. Neglect of that consumption hampers accurate understanding of Si cycling on continental margins. PMID:22355549

  3. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    NASA Astrophysics Data System (ADS)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2014-12-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality at the watershed scale (~ 50 km2) and to identify critical source areas of high nitrate export. A physically based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data to simulate hydrological processes and agricultural nutrient cycling over the period of 1990-2000. To accurately simulate winter cover crop biomass in relation to growing conditions, a new approach was developed to further calibrate plant growth parameters that control the leaf area development curve using multitemporal satellite-based measurements of species-specific winter cover crop performance. Multiple SWAT scenarios were developed to obtain baseline information on nitrate loading without winter cover crops and to investigate how nitrate loading could change under different winter cover crop planting scenarios, including different species, planting dates, and implementation areas. The simulation results indicate that winter cover crops have a negligible impact on the water budget but significantly reduce nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading from agricultural lands was approximately 14 kg ha-1, but decreased to 4.6-10.1 kg ha-1 with cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was the most effective species, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of cover crops (~ 30

  4. Vigorous Root Growth Is a Better Indicator of Early Nutrient Uptake than Root Hair Traits in Spring Wheat Grown under Low Fertility

    PubMed Central

    Wang, Yaosheng; Thorup-Kristensen, Kristian; Jensen, Lars Stoumann; Magid, Jakob

    2016-01-01

    A number of root and root hair traits have been proposed as important for nutrient acquisition. However, there is still a need for knowledge on which traits are most important in determining macro- and micronutrient uptake at low soil fertility. This study investigated the variations in root growth vigor and root hair length (RHL) and density (RHD) among spring wheat genotypes and their relationship to nutrient concentrations and uptake during early growth. Six spring wheat genotypes were grown in a soil with low nutrient availability. The root and root hair traits as well as the concentration and content of macro- and micronutrients were identified. A significant genetic variability in root and root hair traits as well as nutrient uptake was found. Fast and early root proliferation and long and dense root hairs enhanced uptake of macro- and micronutrients under low soil nutrient availability. Vigorous root growth, however, was a better indicator of early nutrient acquisition than RHL and RHD. Vigorous root growth and long and dense root hairs ensured efficient acquisition of macro- and micronutrients during early growth and a high root length to shoot dry matter ratio favored high macronutrient concentrations in the shoots, which is assumed to be important for later plant development. PMID:27379145

  5. Landspreading MSW compost in Wisconsin: Effect on corn yield, nutrient and metal uptake, and soil nitrate-N

    SciTech Connect

    Wolkowski, R.P.

    1995-12-31

    Studies were conducted at several Wisconsin locations from 1991-1994 to determine the effect of municipal solid waste (MSW) compost on corn (Zea mays L.) growth, nutrient and metal uptake, and soil nitrate-N content. Composts of varying maturities were applied at rates ranging between 0 and 56 t/a (dry matter basis), depending on year and location. Commercial fertilizers were applied to separate plots to determine the extent of nutrient availability from the compost. All treatments were applied in the spring and incorporated prior to planting corn. Mature compost always increased growth and yield above the untreated control, but the highest yields were found where recommended fertilizer was applied. Immature compost suppressed growth and reduced yield. Compost generally increased the levels of plant nutrients in the whole-plant tissue and grain. While compost did increase the concentration of some metals in the whole-plant tissue, these levels were found to be within the range expected for corn. Compost did not affect metal concentration in the grain. Soil nitrate-N was higher throughout most of the growing season in treatments receiving recommended N fertilizer.

  6. NUTRIENT UPTAKE AND COMMUNITY METABOLISM IN STREAMS DRAINING HARVESTED AND OLD GROWTH WATERSHEDS: A PRELIMINARY ASSESSMENT

    EPA Science Inventory

    The effect of timber harvesting on streams is assessed using two measures of ecosystem function: nutrient ad community metabolism. This research is being conducted in streams of the southern Appalachian Mountains of North Carolina, the Ouachita Mountains of Arkansas, the Cascad...

  7. Fall fertilization of Pinus resinosa seedlings: nutrient uptake, cold hardiness, and morphological development

    Treesearch

    M. Anisul Islam; Kent G. Apostol; Douglass F. Jacobs; R. Kasten Dumroese

    2009-01-01

    Fertilization is an integral component of nursery culture for production of high quality seedlings for afforestation and reforestation because it can enhance plant growth, nutrient storage reserves, and resistance to biotic and abiotic stresses (Landis, 1985). While fertilizer is conventionally applied during spring and summer in accordance with the...

  8. Salinity limits to shoot and root growth and nutrient uptake in ‘Honeoye’ strawberry

    USDA-ARS?s Scientific Manuscript database

    A study was done to identify salinity thresholds that limit shoot and root development and lead to leaf tissue necrosis in strawberry. Plants were exposed to five levels of salinity from CaCl2 mixed with nutrient solution. Electrical conductivity (EC) of the solutions ranged from 0.3-3.7 dS/m initia...

  9. Corn grain and nutrient uptake response to different swine manure application methods

    USDA-ARS?s Scientific Manuscript database

    Farmers are looking for better management practices to enhance production and reduce negative environmental impact from nitrogen (N) fertilizer application since N is one of the most important and costly nutrient inputs for crop production. In this field experiment pre-plant swine effluent applicati...

  10. NUTRIENT UPTAKE AND COMMUNITY METABOLISM IN STREAMS DRAINING HARVESTED AND OLD GROWTH WATERSHEDS: A PRELIMINARY ASSESSMENT

    EPA Science Inventory

    The effect of timber harvesting on streams is assessed using two measures of ecosystem function: nutrient ad community metabolism. This research is being conducted in streams of the southern Appalachian Mountains of North Carolina, the Ouachita Mountains of Arkansas, the Cascad...

  11. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    NASA Astrophysics Data System (ADS)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2013-11-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991-2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha-1, but it decreased to 4.6-10.1 kg ha-1 with winter cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha-1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils and those

  12. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    USGS Publications Warehouse

    Yeo, In-Young; Lee, Sangchui; Sadeghi, Ali M.; Beeson, Peter C.; Hively, W. Dean; McCarty, Greg W.; Lang, Megan W.

    2013-01-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha−1, but it decreased to 4.6–10.1 kg ha−1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha−1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils

  13. Biotite weathering and nutrient uptake by ectomycorrhizal fungus, Suillus tomentosus, in liquid-culture experiments

    NASA Astrophysics Data System (ADS)

    Balogh-Brunstad, Zsuzsanna; Kent Keller, C.; Thomas Dickinson, J.; Stevens, Forrest; Li, C. Y.; Bormann, Bernard T.

    2008-06-01

    Ectomycorrhiza-forming fungi (EMF) alter the nutrient-acquisition capabilities of vascular plants, and may play an important role in mineral weathering and the partitioning of products of weathering in soils under nutrient-limited conditions. In this study, we isolated the weathering function of Suillus tomentosus in liquid-cultures with biotite micas incubated at room temperature. We hypothesized that the fungus would accelerate weathering by hyphal attachment to biotite surfaces and transmission of nutrient cations via direct exchange into the fungal biomass. We combined a mass-balance approach with scanning electron microscopy (SEM) and atomic force microscopy (AFM) to estimate weathering rates and study dissolution features on biotite surfaces. Weathering of biotite flakes was about 2-3 orders of magnitude faster in shaken liquid-cultures with fungus compared to shaken controls without fungus, but with added inorganic acids. Adding fungus in nonshaken cultures caused a higher dissolution rate than in inorganic pH controls without fungus, but it was not significantly faster than organic pH controls without fungus. The K +, Mg 2+ and Fe 2+ from biotite were preferentially partitioned into fungal biomass in the shaken cultures, while in the nonshaken cultures, K + and Mg 2+ was lost from biomass and Fe 2+ bioaccumulated much less. Fungal hyphae attached to biotite surfaces, but no significant surface changes were detected by SEM. When cultures were shaken, the AFM images of basal planes appeared to be rougher and had abundant dissolution channels, but such channel development was minor in nonshaken conditions. Even under shaken conditions the channels only accounted for only 1/100 of the total dissolution rate of 2.7 × 10 -10 mol of biotite m -2 s -1. The results suggest that fungal weathering predominantly occurred not by attachment and direct transfer of nutrients via hyphae, but because of the acidification of the bulk liquid by organic acids, fungal

  14. Dynamic sinking behaviour in marine phytoplankton: rapid changes in buoyancy may aid in nutrient uptake.

    PubMed

    Gemmell, Brad J; Oh, Genesok; Buskey, Edward J; Villareal, Tracy A

    2016-10-12

    Phytoplankton sinking is an important property that can determine community composition in the photic zone and material loss to the deep ocean. To date, studies of diatom suspension have relied on bulk measurements with assumptions that bulk rates adequately capture the essential characteristics of diatom sinking. However, recent work has illustrated that individual diatom sinking rates vary considerably from the mean bulk rate. In this study, we apply high-resolution optical techniques, individual-based observations of diatom sinking and a recently developed method of flow visualization around freely sinking cells. The results show that in both field samples and laboratory cultures, some large species of centric diatoms are capable of a novel behaviour, whereby cells undergo bursts of rapid sinking that alternate with near-zero sinking rates on the timescales of seconds. We also demonstrate that this behaviour is under direct metabolic control of the cell. We discuss these results in the context of implications for nutrient flux to the cell surface. While nutrient flux in large diatoms increases during fast sinking, current mass transport models cannot incorporate the unsteady sinking behaviour observed in this study. However, large diatoms appear capable of benefiting from the enhanced nutrient flux to their surface during rapid sinking even during brief intervening periods of near-zero sinking rates.

  15. [Effects of reduced N application rate on yield and nutrient uptake and utilization in maize-soybean relay strip intercropping system].

    PubMed

    Yong, Tai-Wen; Liu, Xiao-Ming; Wen-Yu, Liu; Su, Ben-Ying; Song, Chun; Yang, Feng; Wang, Xiao-Chun; Yang, Wen-Yu

    2014-02-01

    A field experiment with three N application rates (0, 180, 240 N kg x hm(-2), representing zero, reduced and conventional N application, respectively) and three planting patterns (maize monoculture, soybean monoculture and maize-soybean relay strip intercropping) was conducted to reveal the effects of cropping patterns and N application rates on yield, nutrient uptake and nitrogen use efficiency of maize and soybean. The results showed that the grain yield, N, P and K uptake and harvest index of the intercropped maize reduced slightly compared with the monoculture maize, however these indices of the intercropped soybean increased significantly compared with the monoculture. With the increase in nitrogen fertilizer application, the excellence of relay strip intercropping was weakened in the maize-soybean intercropping system. The grain yield, economic coefficient, N, P and K uptake, harvest index, N agronomy efficiency and N uptake efficiency of maize and soybean increased significantly at the reduced nitrogen rate (180 N kg x hm(-2)), but the rate of soil N contribution declined, compared with the conventional rate of N application by local farmers (240 N kg x hm(-2)). In the reduced nitrogen rate treatment, total soil N and P contents of the maize strip reduced, whereas the total soil N, P and K contents of soybean strip and the total K content of maize strip increased compared with the zero N application treatment. With the reduced N application, the annual total grain yield, N, P and K uptake of above-ground biomass in the maize-soybean relay strip intercropping system were higher than in the monoculture, and the land equivalent ratio (LER) was 2.28. N uptake efficiency of maize in the relay strip intercropping system was 20.2% higher than in the maize monoculture, and the index of soybean was 30.5% lower than in the monoculture. The rate of soil N contribution in the relay strip intercropping system was 20.0% and 8.8% lower than in the maize and soybean

  16. Colorectal cancer screening: Opportunities to improve uptake, outcomes, and disparities

    PubMed Central

    Shahidi, Neal; Cheung, Winson Y

    2016-01-01

    Colorectal cancer screening has become a standard of care in industrialized nations for those 50 to 75 years of age, along with selected high-risk populations. While colorectal cancer screening has been shown to reduce both the incidence and mortality of colorectal cancer, it is a complex multi-disciplinary process with a number of important steps that require optimization before tangible improvements in outcomes are possible. For both opportunistic and programmatic colorectal cancer screening, poor participant uptake remains an ongoing concern. Furthermore, current screening modalities (such as the guaiac based fecal occult blood test, fecal immunochemical test and colonoscopy) may be used or performed suboptimally, which can lead to missed neoplastic lesions and unnecessary endoscopic evaluations. The latter poses the risk of adverse events, such as perforation and post-polypectomy bleeding, as well as financial impacts to the healthcare system. Moreover, ongoing disparities in colorectal cancer screening persist among marginalized populations, including specific ethnic minorities (African Americans, Hispanics, Asians, Indigenous groups), immigrants, and those who are economically disenfranchised. Given this context, we aimed to review the current literature on these important areas pertaining to colorectal cancer screening, particularly focusing on the guaiac based fecal occult blood test, the fecal immunochemical test and colonoscopy. PMID:28042387

  17. Improved cellular uptake of functionalized single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Antonelli, A.; Serafini, S.; Menotta, M.; Sfara, C.; Pierigé, F.; Giorgi, L.; Ambrosi, G.; Rossi, L.; Magnani, M.

    2010-10-01

    Single-walled carbon nanotubes (SWNTs) due to their unique structural and physicochemical properties, have been proposed as delivery systems for a variety of diagnostic and therapeutic agents. However, SWNTs have proven difficult to solubilize in aqueous solution, limiting their use in biological applications. In an attempt to improve SWNTs' solubility, biocompatibility, and to increase cell penetration we have thoroughly investigated the construction of carbon scaffolds coated with aliphatic carbon chains and phospholipids to obtain micelle-like structures. At first, oxidized SWNTs (2370 ± 30 nmol mg - 1 of SWNTs) were covalently coupled with an alcoholic chain (stearyl alcohol, C18H37OH; 816 nmol mg - 1 of SWNTs). Subsequently, SWNTs-COOC18H37 derivatives were coated with phosphatidylethanolamine (PE) or -serine (PS) phospholipids obtaining micelle-like structures. We found that cellular uptake of these constructs by phagocytic cells occurs via an endocytotic mechanism for constructs larger than 400 nm while occurs via diffusion through the cell membrane for constructs up to 400 nm. The material that enters the cell by phagocytosis is actively internalized by macrophages and localizes inside endocytotic vesicles. In contrast the material that enters the cells by diffusion is found in the cell cytosol. In conclusion, we have realized new biomimetic constructs based on alkylated SWNTs coated with phospholipids that are efficiently internalized by different cell types only if their size is lower than 400 nm. These constructs are not toxic to the cells and could now be explored as delivery systems for non-permeant cargoes.

  18. The Plasmodium falciparum rhoptry protein RhopH3 plays essential roles in host cell invasion and nutrient uptake

    PubMed Central

    Sherling, Emma S; Knuepfer, Ellen; Brzostowski, Joseph A; Miller, Louis H; Blackman, Michael J; van Ooij, Christiaan

    2017-01-01

    Merozoites of the protozoan parasite responsible for the most virulent form of malaria, Plasmodium falciparum, invade erythrocytes. Invasion involves discharge of rhoptries, specialized secretory organelles. Once intracellular, parasites induce increased nutrient uptake by generating new permeability pathways (NPP) including a Plasmodium surface anion channel (PSAC). RhopH1/Clag3, one member of the three-protein RhopH complex, is important for PSAC/NPP activity. However, the roles of the other members of the RhopH complex in PSAC/NPP establishment are unknown and it is unclear whether any of the RhopH proteins play a role in invasion. Here we demonstrate that RhopH3, the smallest component of the complex, is essential for parasite survival. Conditional truncation of RhopH3 substantially reduces invasive capacity. Those mutant parasites that do invade are defective in nutrient import and die. Our results identify a dual role for RhopH3 that links erythrocyte invasion to formation of the PSAC/NPP essential for parasite survival within host erythrocytes. DOI: http://dx.doi.org/10.7554/eLife.23239.001 PMID:28252384

  19. Additive effects due to biochar and endophyte application enable soybean to enhance nutrient uptake and modulate nutritional parameters* #

    PubMed Central

    Waqas, Muhammad; Kim, Yoon-Ha; Khan, Abdul Latif; Shahzad, Raheem; Asaf, Sajjad; Hamayun, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Lee, In-Jung

    2017-01-01

    We studied the effects of hardwood-derived biochar (BC) and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean (Glycine max (L.) Merr.) with respect to basic, macro-and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC+G. geotrichum-treated soybean plants. In comparison, the uptakes of macro-and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC+G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents. PMID:28124840

  20. Additive effects due to biochar and endophyte application enable soybean to enhance nutrient uptake and modulate nutritional parameters.

    PubMed

    Waqas, Muhammad; Kim, Yoon-Ha; Khan, Abdul Latif; Shahzad, Raheem; Asaf, Sajjad; Hamayun, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Lee, In-Jung

    We studied the effects of hardwood-derived biochar (BC) and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean (Glycine max (L.) Merr.) with respect to basic, macro- and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC+G. geotrichum-treated soybean plants. In comparison, the uptakes of macro- and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC+G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents.

  1. Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.): a pot experiment.

    PubMed

    ten Berge, Hein F M; van der Meer, Hugo G; Steenhuizen, Johan W; Goedhart, Paul W; Knops, Pol; Verhagen, Jan

    2012-01-01

    Mineral carbonation of basic silicate minerals regulates atmospheric CO(2) on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO(2) sequestration ('enhanced weathering'). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha(-1). Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha(-1) (14.8% of dose, OLIV1) to 2240 kg ha(-1) (1.1%, OLIV4). This corresponds to gross CO(2) sequestration of 290 to 2690 kg ha(-1) (29 10(3) to 269 10(3) kg km(-2).) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the 'enhanced weathering' concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop.

  2. [Effects of Cd stress on photosynthetic characteristics and nutrient uptake of cabbages with different Cd-tolerance].

    PubMed

    Sun, Jian-yun; Shen, Zhen-guo

    2007-11-01

    With solution culture, this paper studied the plant growth, photosynthetic characteristics and nutrient uptake of two cabbage (Brassica oleracea L.) cultivars with different Cd-tolerance under treatments of 0, 20, 50 and 100 micromol Cd x L(-1). The results showed that the growth of Cd-sensitive cultivar Qiufeng was inhibited obviously even under low Cd concentration (20 micromol x L(-1)) stress. The net photosynthetic rate (P9, stomata1 conductance (Gs), photochemical efficiency of PS II (Fv/Fm) and quantum yield of electron flow through PS II (phi (PS II)) in its leaves and the dry weight of its shoots and roots declined sharply. However, negative impact on the growth and photosynthetic characteristics of Cd-tolerant cultivar Beinongzaosheng was only observed under high Cd concentration (50 and 100 micromol x L(-1)) stress. Cd stress decreased the contents of chlorophyll a and b, especially of chlorophyll b, which could be an important factor of photosynthesis inhibition. Under Cd stress, the Mn uptake by plant decreased significantly, and the transportation of Fe and Mg from roots to shoots was restrained, which were more obvious in Cd-sensitive than in Cd-tolerant cultivar. Cd stress promoted the P and S uptake by Cd-tolerant cultivar, but opposite results were observed in Cd-sensitive cultivar. Therefore, physiologically, the decrease of Mn, Fe, Mg, S and P concentrations in Cd-sensitive cultivar's leaves under Cd stress was the key reason for the restraint of leaf photosynthesis, and the decrease of plant growth.

  3. Olivine Weathering in Soil, and Its Effects on Growth and Nutrient Uptake in Ryegrass (Lolium perenne L.): A Pot Experiment

    PubMed Central

    ten Berge, Hein F. M.; van der Meer, Hugo G.; Steenhuizen, Johan W.; Goedhart, Paul W.; Knops, Pol; Verhagen, Jan

    2012-01-01

    Mineral carbonation of basic silicate minerals regulates atmospheric CO2 on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO2 sequestration (‘enhanced weathering’). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha−1. Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha−1 (14.8% of dose, OLIV1) to 2240 kg ha−1 (1.1%, OLIV4). This corresponds to gross CO2 sequestration of 290 to 2690 kg ha−1 (29 103 to 269 103 kg km−2.) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the ‘enhanced weathering’ concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop. PMID:22912685

  4. Effect of fouling organisms on food uptake and nutrient release of scallop ( Chlamys nobilis, Reeve) cultured in Daya Bay

    NASA Astrophysics Data System (ADS)

    Su, Zhenxia; Xiao, Hui; Yan, Yan; Huang, Liangmin

    2008-02-01

    Biofouling is an important factor that affects the bivalve farming industry. Fouling organisms may reduce growth and survival rate of the cultured species. Fouler are often filter feeders, so they are potential competitors for food resource with the cultured species. The present study was conducted to measure the impact of fouling on food uptake and nutrient release in April and June, 2006 in Daya Bay near Guangzhou, China. Results showed that fouling organisms had significant effect on food uptake and nutrient release. The chlorophyll a uptake rate of fouled scallops was 7.53Lh-1±1.416Lh-1 and 11.94Lh-1±2.497Lh-1 in April and June, respectively, significantly higher than those of cleaned scallops, i.e., 4.23Lh-1±2.744Lh-1 and 2.57Lh-1±1.832Lh-1 respectively. The consumption of total particulate matter by fouled scallops in April and June was 5.52Lh-1±0.818Lh-1 and 3.07Lh-1±0.971Lh-1, respectively; the corresponding results for cleaned scallops are 2.49Lh-1±0.614Lh-1 and 2.37±1.214Lh-1, respectively. Fouling increased ammonia release significantly. The ammonia release rate of fouled scallops was 33.81Lh-1±7.699Lh-1 and 76.39Lh-1±9.251Lh-1 in April and June, while cleaned scallops released 2.46Lh-1±0.511Lh-1 and 7.23Lh-1±1.026Lh-1 ammonia, respectively. Phosphate release of fouled scallops was 22.72Lh-1±9.978Lh-1 in June and cleaned scallops released phosphate 6.01Lh-1±0.876Lh-1 in April. Therefore, fouling contributed much to food reduction and concentration increase of ammonia and phosphate in water.

  5. Effect of arbuscular mycorrhizal colonization and two levels of compost supply on nutrient uptake and flowering of pelargonium plants.

    PubMed

    Perner, Henrike; Schwarz, Dietmar; Bruns, Christian; Mäder, Paul; George, Eckhard

    2007-07-01

    Two challenges frequently encountered in the production of ornamental plants in organic horticulture are: (1) the rate of mineralization of phosphorus (P) and nitrogen (N) from organic fertilizers can be too slow to meet the high nutrient demand of young plants, and (2) the exclusive use of peat as a substrate for pot-based plant culture is discouraged in organic production systems. In this situation, the use of beneficial soil microorganisms in combination with high quality compost substrates can contribute to adequate plant growth and flower development. In this study, we examined possible alternatives to highly soluble fertilizers and pure peat substrates using pelargonium (Pelargonium peltatum L'Her.) as a test plant. Plants were grown on a peat-based substrate with two rates of compost addition and with and without arbuscular mycorrhizal (AM) fungi. Inoculation with three different commercial AM inocula resulted in colonization rates of up to 36% of the total root length, whereas non-inoculated plants remained free of root colonization. Increasing the rate of compost addition increased shoot dry weight and shoot nutrient concentrations, but the supply of compost did not always completely meet plant nutrient demand. Mycorrhizal colonization increased the number of buds and flowers, as well as shoot P and potassium (K) concentrations, but did not significantly affect shoot dry matter or shoot N concentration. We conclude that addition of compost in combination with mycorrhizal inoculation can improve nutrient status and flower development of plants grown on peat-based substrates.

  6. Does cluster-root activity benefit nutrient uptake and growth of co-existing species?

    PubMed

    Muler, Ana L; Oliveira, Rafael S; Lambers, Hans; Veneklaas, Erik J

    2014-01-01

    Species that inhabit phosphorus- (P) and micronutrient-impoverished soils typically have adaptations to enhance the acquisition of these nutrients, for example cluster roots in Proteaceae. However, there are several species co-occurring in the same environment that do not produce similar specialised roots. This study aims to investigate whether one of these species (Scholtzia involucrata) can benefit from the mobilisation of P or micronutrients by the cluster roots of co-occurring Banksia attenuata, and also to examine the response of B. attenuata to the presence of S. involucrata. We conducted a greenhouse experiment, using a replacement series design, where B. attenuata and S. involucrata shared a pot at proportions of 2:0, 1:2 and 0:4. S. involucrata plants grew more in length, were heavier and had higher manganese (Mn) concentrations in their young leaves when grown next to one individual of B. attenuata and one individual of S. involucrata than when grown with three conspecifics. All S. involucrata individuals were colonised by arbuscular mycorrhizal fungi, and possibly Rhizoctonia. Additionally, P concentration was higher in the young leaves of B. attenuata when grown with another B. attenuata than when grown with two individuals of S. involucrata, despite the smaller size of the S. involucrata individuals. Our results demonstrate that intraspecific competition was stronger than interspecific competition for S. involucrata, but not for B. attenuata. We conclude that cluster roots of B. attenuata facilitate the acquisition of nutrients by neighbouring shrubs by making P and Mn more available for their neighbours.

  7. Effect of residue combinations on plant uptake of nutrients and potentially toxic elements.

    PubMed

    Brännvall, Evelina; Nilsson, Malin; Sjöblom, Rolf; Skoglund, Nils; Kumpiene, Jurate

    2014-01-01

    The aim of the plant pot experiment was to evaluate potential environmental impacts of combined industrial residues to be used as soil fertilisers by analysing i) element availability in fly ash and biosolids mixed with soil both individual and in combination, ii) changes in element phytoavailability in soil fertilised with these materials and iii) impact of the fertilisers on plant growth and element uptake. Plant pot experiments were carried out, using soil to which fresh residue mixtures had been added. The results showed that element availability did not correlate with plant growth in the fertilised soil with. The largest concentrations of K (3534 mg/l), Mg (184 mg/l), P (1.8 mg/l), S (760 mg/l), Cu (0.39 mg/l) and Zn (0.58 mg/l) in soil pore water were found in the soil mixture with biosolids and MSWI fly ashes; however plants did not grow at all in mixtures containing the latter, most likely due to the high concentration of chlorides (82 g/kg in the leachate) in this ash. It is known that high salinity of soil can reduce germination by e.g. limiting water absorption by the seeds. The concentrations of As, Cd and Pb in grown plants were negligible in most of the soils and were below the instrument detection limit values. The proportions of biofuel fly ash and biosolids can be adjusted in order to balance the amount and availability of macronutrients, while the possible increase of potentially toxic elements in biomass is negligible seeing as the plant uptake of such elements was low. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Improvement of HSPF watershed model in plant uptake and DIN export from forest

    NASA Astrophysics Data System (ADS)

    Wang, P.; Linker, L. C.

    2001-12-01

    Correct simulation of nutrient export in response to flow is important in watershed models. In HSPF, plant uptake of dissolved inorganic nitrogen (DIN) affects the export of DIN from sloped soil layers to a stream. Plant uptake depends on soil moisture. When moisture is deficient, increasing moisture may increase mass uptake; when moisture is over-sufficient, increasing moisture may dilute solution concentrations and decrease mass uptake in unit time. Detailed analysis of the effect of moisture on plant uptake and DIN export is presented. The two different relationships of soil moisture and uptake can be simulated by using the Michaelis-Menton saturation kinetics with two different mechanisms by applying different units of the maximum plant uptake rate, respectively. HSPF version 11 uses a single mechanism for all ranges of moisture conditions. This paper firstly compares two methods in plant uptakes. 1) The HSPF version 11 uses concentration (per unit time) as the unit of maximum uptake rate, which results in higher uptake in higher moisture conditions. It is good in moisture deficient condition, but is not good for moisture over-sufficient condition and results in some strange high DIN loads in some moderate low flow days. 2) The Alternative Method uses mass (per unit area per unit time) as the unit of maximum uptake rate, which is good in moisture sufficient condition and results in a better DIN load-flow relationship, because significant DIN load is usually associated with excessive moisture conditions. However, it overestimates uptake in moisture deficient condition and slightly underestimates DIN load associated with some very low flows. A sensitivity analysis is conducted with different precipitation factors to generate different flows. The HSPF version 11 yields lower yearly loads in the runs with greater precipitation factors, whereas, the Alternative Method yields higher load in the runs with greater factors. Overall, the Alternative Method provides

  9. Chromium phytotoxicity in radish (Raphanus sativus): effects on metabolism and nutrient uptake.

    PubMed

    Tiwari, K K; Singh, N K; Rai, U N

    2013-09-01

    In the present investigation, chromium (VI) induced toxicity on metabolic activity and translocations of nutrients in radish were evaluated under controlled glass house conditions. Chromium was found to induce toxicity and significantly affect plant growth and metabolic activity. Excess of chromium (0.4 mM) caused a decrease in the concentration of iron in leaves (from 134.3 to 71.9 μg g(-1) dw) and significant translocation of sulphur, phosphorus and zinc. Translocation of manganese, copper and boron were less affected from root to stem. After 15 days of Cr exposure, maximum accumulation of Cr was found in roots (327.6 μg g(-1) dw) followed by stems (186.8 μg g(-1) dw) and leaves (116.7 μg g(-1) dw) at 0.4 mM Cr concentration. Therefore, Cr may affect negatively not only production, but also the nutritive quality of the radish; likewise, higher Cr content may cause health hazards for humans.

  10. Biology of SLAC1-type anion channels - from nutrient uptake to stomatal closure.

    PubMed

    Hedrich, Rainer; Geiger, Dietmar

    2017-10-01

    Contents 46 I. 46 II. 47 III. 50 IV. 53 V. 56 VI. 57 58 58 References 58 SUMMARY: Stomatal guard cells control leaf CO2 intake and concomitant water loss to the atmosphere. When photosynthetic CO2 assimilation is limited and the ratio of CO2 intake to transpiration becomes suboptimal, guard cells, sensing the rise in CO2 concentration in the substomatal cavity, deflate and the stomata close. Screens for mutants that do not close in response to experimentally imposed high CO2 atmospheres identified the guard cell-expressed Slowly activating anion channel, SLAC1, as the key player in the regulation of stomatal closure. SLAC1 evolved, though, before the emergence of guard cells. In Arabidopsis, SLAC1 is the founder member of a family of anion channels, which comprises four homologues. SLAC1 and SLAH3 mediate chloride and nitrate transport in guard cells, while SLAH1, SLAH2 and SLAH3 are engaged in root nitrate and chloride acquisition, and anion translocation to the shoot. The signal transduction pathways involved in CO2 , water stress and nutrient-sensing activate SLAC/SLAH via distinct protein kinase/phosphatase pairs. In this review, we discuss the role that SLAC/SLAH channels play in guard cell closure, on the one hand, and in the root-shoot continuum on the other, along with the molecular basis of the channels' anion selectivity and gating. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  11. Is the stokeslet model sufficient for finding nutrient uptake of microscopic suspension feeders?

    NASA Astrophysics Data System (ADS)

    Lutton, Alexander T.; Pepper, Rachel E.

    2016-11-01

    Microscopic sessile suspension feeders are part of many aquatic ecosystems. They are single-celled, vary in size from a few to about 100 microns in length, live attached to substrates, and serve important ecological roles as both food for larger organisms and consumers of bacteria and other small particles. These organisms create currents in order to bring food toward them. Understanding these currents may allow us not only deeper insight into the ecology of aquatic ecosystems, but also may enable innovation in water treatment. Simulations of the feeding currents of these organisms typically use a simple model that places a stokeslet above an infinite plane boundary representing the surface of attachment. This model produces a useful approximation for the flow field of the organism, but may be of limited accuracy when the organism is near the boundary. We create a different model composed of a stokeslet and a potential dipole, which form a sphere. This sphere has a sin(θ) tangential velocity boundary condition, accounting for the cell body. Using nutrient flux to the organism as our metric, we investigate the discrepancy between the spherical and stokeslet models in order to determine the efficacy of the stokeslet model as an approximation of single-celled suspension feeders.

  12. Influence of Mount St. Helens volcanic ash on alfalfa growth and nutrient uptake

    SciTech Connect

    Mahler, R.L.

    1984-01-01

    Concern has been expressed that large amounts of volcanic ash from the May 18, 1980 eruption of Mount St. Helens may have created potential nutritional problems associated with forage production in northern Idaho and eastern Washington to the extent that adjustments need to be made in soil test correlation data. The objectives of this greenhouse study were to : (1) determine the effect of varying amounts of volcanic ash mixed into soils of northern Idaho on total alfalfa biomass production, and (2) to determine the effect of various soil/ash mixtures on the nutrient concentrations of P, K, S, Ca, Mg, Mn and Zn in alfalfa. Alfalfa was grown in eight different northern Idaho soils amended with differing levels of volcanic ash (0, 20, 35, 50 and 75%) in the greenhouse. The alfalfa seeds were inoculated and fertilizer P and S were added to all treatments. Total plant biomass and P, K, S, Ca, Mg, Mn and Zn plant concentrations were measured. The eight were pooled for analysis and it was found that increasing amounts of volcanic ash increased alfalfa biomass production. Plant P, S, Ca, Mg and Zn concentrations also increased with increasing levels of ash. Conversely, increasing levels of ash resulted in lower alfalfa tissue K and Mn concentrations. 13 references, 7 figures.

  13. Prospective Zinc Solubilising Bacteria for Enhanced Nutrient Uptake and Growth Promotion in Maize (Zea mays L.).

    PubMed

    Goteti, Praveen Kumar; Emmanuel, Leo Daniel Amalraj; Desai, Suseelendra; Shaik, Mir Hassan Ahmed

    2013-01-01

    Zinc (Zn) is one of the essential micronutrients required for optimum plant growth. Substantial quantity of applied inorganic zinc in soil is converted into unavailable form. Zinc solubilising bacteria are potential alternates for zinc supplement. Among 10 strains screened for Zn solubilisation, P29, P33, and B40 produced 22.0 mm clear haloes on solid medium amended with ZnCO3. Similarly, P17 and B40 showed 31.0 mm zone in ZnO incorporated medium. P29 and B40 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18 and 17 ppm), respectively. The pH of the broth was almost acidic in all the cases ranging from 3.9 to 6.1 in ZnCO3 and from 4.1 to 6.4 in ZnO added medium. Short term pot culture experiment with maize revealed that seed bacterization with P29 @ 10 g·kg(-1) significantly enhanced total dry mass (12.96 g) and uptake of N (2.268%), K (2.0%), Mn (60 ppm), and Zn (278.8 ppm).

  14. Prospective Zinc Solubilising Bacteria for Enhanced Nutrient Uptake and Growth Promotion in Maize (Zea mays L.)

    PubMed Central

    Goteti, Praveen Kumar; Emmanuel, Leo Daniel Amalraj; Desai, Suseelendra; Shaik, Mir Hassan Ahmed

    2013-01-01

    Zinc (Zn) is one of the essential micronutrients required for optimum plant growth. Substantial quantity of applied inorganic zinc in soil is converted into unavailable form. Zinc solubilising bacteria are potential alternates for zinc supplement. Among 10 strains screened for Zn solubilisation, P29, P33, and B40 produced 22.0 mm clear haloes on solid medium amended with ZnCO3. Similarly, P17 and B40 showed 31.0 mm zone in ZnO incorporated medium. P29 and B40 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18 and 17 ppm), respectively. The pH of the broth was almost acidic in all the cases ranging from 3.9 to 6.1 in ZnCO3 and from 4.1 to 6.4 in ZnO added medium. Short term pot culture experiment with maize revealed that seed bacterization with P29 @ 10 g·kg−1 significantly enhanced total dry mass (12.96 g) and uptake of N (2.268%), K (2.0%), Mn (60 ppm), and Zn (278.8 ppm). PMID:24489550

  15. Mycorrhizal mediated feedbacks influence net carbon gain and nutrient uptake in Andropogon gerardii.

    SciTech Connect

    Miller, R. M.; Miller, S. P.; Jastrow, J. D.; Rivetta, C. B.; Environmental Research

    2002-07-01

    The carbon sink strength of arbuscular mycorrhizal fungi (AMF) was investigated by comparing the growth dynamics of mycorrhizal and nonmycorrhizal Andropogon gerardii plants over a wide range of equivalent tissue phosphorus : nitrogen (P : N) ratios. Host growth, apparent photosynthesis (A{sub net}), net C gain (C{sub n}) and P and N uptake were evaluated in sequential harvests of mycorrhizal and nonmycorrhizal A. gerardii plants. Response curves were used to assess the effect of assimilate supply on the mycorrhizal symbiosis in relation to the association of C with N and P. Mycorrhizal plants had higher C{sub n} than nonmycorrhizal plants at equivalent shoot P : N ratios even though colonization did not affect plant dry mass. The higher C{sub n} in mycorrhizal plants was related to both an increase in specific leaf area and enhanced photosynthesis. The additional carbon gain associated with the mycorrhizal condition was not allocated to root biomass. The C{sub n} in the mycorrhizal plants was positively related to the proportion of active colonization in the roots. The calculated difference between C{sub n} values in mycorrhizal and nonmycorrhizal plants, C{sub diff}, appeared to correspond to the sink strength of the AMF and was not an indirect result of enhanced nutrition in mycorrhizal plants.

  16. Characterizing nutrient uptake kinetics for efficient crop production during Solanum lycopersicum var. cerasiforme Alef. growth in a closed indoor hydroponic system.

    PubMed

    Lee, Ju Yeon; Rahman, Arifur; Azam, Hossain; Kim, Hyung Seok; Kwon, Man Jae

    2017-01-01

    A balanced nutrient supply is essential for the healthy growth of plants in hydroponic systems. However, the commonly used electrical conductivity (EC)-based nutrient control for plant cultivation can provide amounts of nutrients that are excessive or inadequate for proper plant growth. In this study, we investigated the kinetics of major and minor nutrient uptake in a nutrient solution during the growth of tomato (Solanum lycopersicum var. cerasiforme Alef.) in a closed hydroponic system. The concentrations of major and minor ions in the nutrient solution were determined by various analytical methods including inductively coupled plasma-optical emission spectroscopy (ICP-OES), ion chromatography (IC), ion specific electrodes, and/or colorimetric methods. The concentrations of the individual nutrient ions were compared with changes in the EC. The EC of the nutrient solution varied according to the different growth stages of tomato plants. Variation in the concentrations of NO3-, SO42-, Mg2+, Ca2+, and K+ was similar to the EC variation. However, in the cases of PO43-, Na+, Cl-, dissolved Fe and Mn, Cu2+, and Zn2+, variation did not correspond with that of EC. These ions were generally depleted (to 0 mg L-1) during tomato growth, suggesting that these specific ions should be monitored individually and their supply increased. Nutrient uptake rates of major ions increased gradually at different growth stages until harvest (from < 3 mg L-1 d-1 to > 15 mg L-1 d-1). Saturation indices determined by MINEQL+ simulation and a mineral precipitation experiment demonstrated the potential for amorphous calcium phosphate precipitation, which may facilitate the abiotic adsorptive removal of dissolved Fe, dissolved Mn, Cu2+, and Zn2+.

  17. Characterizing nutrient uptake kinetics for efficient crop production during Solanum lycopersicum var. cerasiforme Alef. growth in a closed indoor hydroponic system

    PubMed Central

    Lee, Ju Yeon; Rahman, Arifur; Azam, Hossain; Kim, Hyung Seok

    2017-01-01

    A balanced nutrient supply is essential for the healthy growth of plants in hydroponic systems. However, the commonly used electrical conductivity (EC)-based nutrient control for plant cultivation can provide amounts of nutrients that are excessive or inadequate for proper plant growth. In this study, we investigated the kinetics of major and minor nutrient uptake in a nutrient solution during the growth of tomato (Solanum lycopersicum var. cerasiforme Alef.) in a closed hydroponic system. The concentrations of major and minor ions in the nutrient solution were determined by various analytical methods including inductively coupled plasma-optical emission spectroscopy (ICP-OES), ion chromatography (IC), ion specific electrodes, and/or colorimetric methods. The concentrations of the individual nutrient ions were compared with changes in the EC. The EC of the nutrient solution varied according to the different growth stages of tomato plants. Variation in the concentrations of NO3−, SO42−, Mg2+, Ca2+, and K+ was similar to the EC variation. However, in the cases of PO43−, Na+, Cl−, dissolved Fe and Mn, Cu2+, and Zn2+, variation did not correspond with that of EC. These ions were generally depleted (to 0 mg L−1) during tomato growth, suggesting that these specific ions should be monitored individually and their supply increased. Nutrient uptake rates of major ions increased gradually at different growth stages until harvest (from < 3 mg L−1 d−1 to > 15 mg L−1 d−1). Saturation indices determined by MINEQL+ simulation and a mineral precipitation experiment demonstrated the potential for amorphous calcium phosphate precipitation, which may facilitate the abiotic adsorptive removal of dissolved Fe, dissolved Mn, Cu2+, and Zn2+. PMID:28486501

  18. Elemental ratios and the uptake and release of nutrients by phytoplankton and bacteria in three lakes of the Canadian shield.

    PubMed

    Elser, J J; Chrzanowski, T H; Sterner, R W; Schampel, J H; Foster, D K

    1995-03-01

    The dynamics of carbon (C), nitrogen (N), and phosphorus (P), elemental ratios, and dark uptake/release of N and P in bacterial and phytoplankton size fractions were studied during summer 1992 in three lakes of contrasting food web structure and trophic status (L240, L110, L227). We wished to determine if phytoplankton and bacteria differed in their elemental characteristics and to evaluate whether the functional role of bacteria in nutrient cycling (i.e., as sink or source) depended on bacterial elemental characteristics. Bacterial contributions to total suspended particulate material and to fluxes of nutrients in the dark were substantial and varied for different elements. This indicated that some techniques for assaying phytoplankton physiological condition are compromised by bacterial contributions. C/N ratios were generally less variable than C/P and N/P ratios. Both elemental ratios and biomass-normalized N and P flux indicated that phytoplankton growth in each lake was predominantly P-limited, although in L227 these data reflect the dominance of N-fixing cyanobacteria, and N was likely limiting early in the sampling season. In L227, phytoplankton N/P ratio and biomass-normalized N flux were negatively correlated, indicating that flux data were likely a reasonable measure of the N status of the phytoplankton. However, for L227 phytoplankton, P-flux per unit biomass was a hyperbolic function of N/P, suggesting that the dominant L227 cyanobacteria have a limited uptake and storage capacity and that P-flux per unit biomass may not be a good gauge of the P-limitation status of phytoplankton in this situation. Examination of N-flux data in the bacterial size fraction relative to the N/P ratio of the bacteria revealed a threshold N/P ratio (∼22:1 N/P, by atoms), below which, bacteria took up and sequestered added N, and above which, N was released. Thus, the functional role of bacteria in N cycling in these ecosystems depended on their N/P stoichiometry.

  19. Effect of iron stress on Withania somnifera L.: antioxidant enzyme response and nutrient elemental uptake of in vitro grown plants.

    PubMed

    Rout, Jyoti Ranjan; Behera, Sadhana; Keshari, Nitin; Ram, Shidharth Sankar; Bhar, Subhajit; Chakraborty, Anindita; Sudarshan, Mathummal; Sahoo, Santi Lata

    2015-03-01

    In the present study the response of antioxidant enzyme activities and the level of expression of their corresponding genes on bioaccumulation of iron (Fe) were investigated. In vitro germinated Withania somnifera L. were grown in Murashige and Skoog's liquid medium with increasing concentrations (0, 25, 50, 100 and 200 µM) of FeSO4 for 7 and 14 days. Root and leaf tissues analyzed for catalase (CAT, EC 1.11.1.6), superoxide dismutase (SOD, EC 1.15.1.1) and guaiacol peroxidase (GPX, EC 1.11.1.7), have shown an increase in content with respect to exposure time. Isoforms of CAT, SOD and GPX were separated using non-denaturing polyacrylamide gel electrophoresis and observed that the isoenzymes were greatly affected by higher concentrations of Fe. Reverse transcriptase polymerase chain reaction analysis performed by taking three pairs of genes of CAT (RsCat, Catalase1, Cat1) and SOD (SodCp, TaSOD1.2, MnSOD) to find out the differential expression of antioxidant genes under Fe excess. RsCat from CAT and MnSOD from SOD have exhibited high levels of gene expression under Fe stress, which was consistent with the changes of the activity assayed in solution after 7 days of treatment. Analysis by proton induced X-ray emission exhibited an increasing uptake of Fe in plants by suppressing and expressing of other nutrient elements. The results of the present study suggest that higher concentration of Fe causes disturbance in nutrient balance and induces oxidative stress in plant.

  20. Contrary seasonal changes of rates of nutrient uptake, organ mass, and voluntary food intake in red deer (Cervus elaphus)

    PubMed Central

    Beiglböck, Christoph; Burmester, Marion; Guschlbauer, Maria; Lengauer, Astrid; Schröder, Bernd; Wilkens, Mirja; Breves, Gerhard

    2015-01-01

    Northern ungulates acclimatize to winter conditions with restricted food supply and unfavorable weather conditions by reducing energy expenditure and voluntary food intake. We investigated in a study on red deer whether rates of peptide and glucose transport in the small intestines are also reduced during winter as part of the thrifty phenotype of winter-acclimatized animals, or whether transport rates are increased during winter in order to exploit poor forage more efficiently. Our results support the latter hypothesis. We found in a feeding experiment that total energy intake was considerably lower during winter despite ad libitum feeding. Together with reduced food intake, mass of visceral organs was significantly lower and body fat reserves were used as metabolic fuel in addition to food. However, efficacy of nutrient absorption seemed to be increased simultaneously. Extraction of crude protein from forage was higher in winter animals, at any level of crude protein intake, as indicated by the lower concentration of crude protein in feces. In line with these in vivo results, Ussing chamber experiments revealed greater electrogenic responses to both peptides and glucose in the small intestines of winter-acclimatized animals, and peptide uptake into jejunal brush-border membrane vesicles was increased. We conclude that reduced appetite of red deer during winter avoids energy expenditure for unproductive search of scarcely available food and further renders the energetically costly maintenance of a large gut and visceral organs unnecessary. Nevertheless, extraction of nutrients from forage is more efficient in the winter to attenuate an inevitably negative energy balance. PMID:26017492

  1. Effect of elicitation on growth, respiration, and nutrient uptake of root and cell suspension cultures of Hyoscyamus muticus.

    PubMed

    Carvalho, Edgard B; Curtis, Wayne R

    2002-01-01

    The elicitation of Hyoscyamus muticus root and cell suspension cultures by fungal elicitor from Rhizoctonia solani causes dramatic changes in respiration, nutrient yields, and growth. Cells and mature root tissues have similar specific oxygen uptake rates (SOUR) before and after the onset of the elicitation process. Cell suspension SOUR were 11 and 18 micromol O2/g FW x h for non-elicited control and elicited cultures, respectively. Mature root SOUR were 11 and 24 micromol O2/g FW x h for control and elicited tissue, respectively. Tissue growth is significantly reduced upon the addition of elicitor to these cultures. Inorganic yield remains fairly constant, whereas yield on sugar is reduced from 0.532 to 0.352 g dry biomass per g sugar for roots and 0.614 to 0.440 g dry biomass per g sugar for cells. This reduction in yield results from increased energy requirements for the defense response. Growth reduction is reflected in a reduction in root meristem (tip) SOUR, which decreased from 189 to 70 micromol O2/g FW x h upon elicitation. Therefore, despite the increase in total respiration, the maximum local oxygen fluxes are reduced as a result of the reduction in metabolic activity at the meristem. This distribution of oxygen uptake throughout the mature tissue could reduce mass transfer requirements during elicited production. However, this was not found to be the case for sesquiterpene elicitation, where production of lubimin and solavetivone were found to increase linearly up to oxygen partial pressures of 40% O2 in air. SOUR is shown to similarly increase in both bubble column and tubular reactors despite severe mass transfer limitations, suggesting the possibility of metabolically induced increases in tissue convective transport during elicitation.

  2. Municipal wastewater renovation, growth and nutrient uptake in an immature conifer-hardwood plantation

    Treesearch

    D.G. Brockway; G. Schneider; D.P. White

    1979-01-01

    The impact of wastewater applications upon a variety of forest ecosystems has received widespread attention in the United States over the past 20 years. During this period the efforts of many researchers have improved our under- standing of the species composition and site characteristics which are appropriate for wastewater irrigation in various forest types (Smith...

  3. Effects of Selected Surfactants on Nutrient Uptake and Soil Microbial Activity

    USDA-ARS?s Scientific Manuscript database

    Surfactants are adjuvants that facilitate and accentuate the emulsifying, dispersing, spreading, wetting, or other surface modifying properties of liquids. Many pesticides require the addition of a surfactant to improve pesticide performance in spray solution. Soils are one of the direct recipients ...

  4. Effects of Posidonia oceanica beach-cast on germination, growth and nutrient uptake of coastal dune plants.

    PubMed

    Del Vecchio, Silvia; Marbà, Núria; Acosta, Alicia; Vignolo, Clara; Traveset, Anna

    2013-01-01

    Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus) that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control) with those growing in a substrate enriched with P. oceanica wrack (treatment) in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P). Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems.

  5. Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan on In Vitro Seeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea mays L.)

    PubMed Central

    Agbodjato, Nadège A.; Noumavo, Pacôme A.; Adjanohoun, Adolphe; Agbessi, Léonce; Baba-Moussa, Lamine

    2016-01-01

    This study aimed to assess the effects of three plant growth promoting rhizobacteria (PGPR) and chitosan either singly or in combination on maize seeds germination and growth and nutrient uptake. Maize seeds were treated with chitosan and bacterial solution. The germination and growth tests were carried out in square Petri dishes and plastic pots. The combination chitosan-A. lipoferum-P. fluorescens has increased the seeds vigor index up to 36.44% compared to the control. In comparison to the control, P. putida has significantly improved root weight (44.84%) and germinated seed weight (31.39%) whereas chitosan-P. putida has increased the shoot weight (65.67%). For the growth test, the maximal heights (17.66%) were obtained by plants treated with the combination A. lipoferum-P. fluorescens-P. putida. Chitosan-P. fluorescens induced the highest increases of leaves per plant (50.09%), aerial (84.66%), and underground biomass (108.77%) production. The plants inoculated with A. lipoferum had the large leaf areas with an increase of 54.08%, while combinations P. fluorescens-P. putida and chitosan-A. lipoferum improved the aerial and underground dry matter of plants to 26.35% and 18.18%. The nitrogen content of the plants was increased by chitosan-A. lipoferum-P. fluorescens-P. putida with an increasing of 41.61%. The combination of chitosan and PGPR can be used as biological fertilizers to increase maize production. PMID:26904295

  6. Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan on In Vitro Seeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea mays L.).

    PubMed

    Agbodjato, Nadège A; Noumavo, Pacôme A; Adjanohoun, Adolphe; Agbessi, Léonce; Baba-Moussa, Lamine

    2016-01-01

    This study aimed to assess the effects of three plant growth promoting rhizobacteria (PGPR) and chitosan either singly or in combination on maize seeds germination and growth and nutrient uptake. Maize seeds were treated with chitosan and bacterial solution. The germination and growth tests were carried out in square Petri dishes and plastic pots. The combination chitosan-A. lipoferum-P. fluorescens has increased the seeds vigor index up to 36.44% compared to the control. In comparison to the control, P. putida has significantly improved root weight (44.84%) and germinated seed weight (31.39%) whereas chitosan-P. putida has increased the shoot weight (65.67%). For the growth test, the maximal heights (17.66%) were obtained by plants treated with the combination A. lipoferum-P. fluorescens-P. putida. Chitosan-P. fluorescens induced the highest increases of leaves per plant (50.09%), aerial (84.66%), and underground biomass (108.77%) production. The plants inoculated with A. lipoferum had the large leaf areas with an increase of 54.08%, while combinations P. fluorescens-P. putida and chitosan-A. lipoferum improved the aerial and underground dry matter of plants to 26.35% and 18.18%. The nitrogen content of the plants was increased by chitosan-A. lipoferum-P. fluorescens-P. putida with an increasing of 41.61%. The combination of chitosan and PGPR can be used as biological fertilizers to increase maize production.

  7. Glucose oxidation positively regulates glucose uptake and improves cardiac function recovery after myocardial reperfusion.

    PubMed

    Li, Tingting; Xu, Jie; Qin, Xinghua; Hou, Zuoxu; Guo, Yongzheng; Liu, Zhenhua; Wu, Jianjiang; Zheng, Hong; Zhang, Xing; Gao, Feng

    2017-03-21

    Myocardial reperfusion decreases glucose oxidation and uncouples glucose oxidation from glycolysis. Therapies that increase glucose oxidation lessen myocardial ischemia/reperfusion injury. However, the regulation of glucose uptake during reperfusion remains poorly understood. Here we found that glucose uptake was remarkably diminished in myocardium following reperfusion in Sprague-Dawley rats as detected by 18F-labeled and fluorescent-labeled glucose analogs, even though GLUT1 was upregulated by 3 folds and GLUT4 translocation remained unchanged compared with those of sham rats. The decreased glucose uptake was accompanied by suppressed glucose oxidation. Interestingly, stimulating glucose oxidation by inhibition of pyruvate dehydrogenase kinase 4 (PDK4), a rate-limiting enzyme for glucose oxidation, increased glucose uptake and alleviated ischemia/reperfusion injury. In vitro data in neonatal myocytes showed that PDK4 overexpression decreased glucose uptake, while its knockdown increased glucose uptake, suggesting a role of PDK4 in regulating glucose uptake. Moreover, inhibition of PDK4 increased myocardial glucose uptake with concomitant enhancement of cardiac insulin sensitivity following myocardial ischemia/reperfusion. These results showed that the suppressed glucose oxidation mediated by PDK4 contributes to the reduced glucose uptake in myocardium following reperfusion, and enhancement of glucose uptake exerts cardioprotection. The findings suggest that stimulating glucose oxidation via PDK4 could be an efficient approach to improve recovery from myocardial ischemia/reperfusion injury.

  8. Effectiveness of native and exotic arbuscular mycorrhizal fungi on nutrient uptake and ion homeostasis in salt-stressed Cajanus cajan L. (Millsp.) genotypes.

    PubMed

    Garg, Neera; Pandey, Rekha

    2015-04-01

    Soil salinity is an increasing problem worldwide, restricting plant growth and production. Research findings show that arbuscular mycorrhizal (AM) fungi have the potential to reduce negative effects of salinity. However, plant growth responses to AM fungi vary as a result of genetic variation in mycorrhizal colonization and plant growth responsiveness. Thus, profitable use of AM requires selection of a suitable combination of host plant and fungal partner. A greenhouse experiment was conducted to compare effectiveness of a native AM fungal inoculum sourced from saline soil and two single exotic isolates, Funneliformis mossseae and Rhizophagus irregularis (single or dual mix), on Cajanus cajan (L.) Millsp. genotypes (Paras and Pusa 2002) under salt stress (0-100 mM NaCl). While salinity reduced plant biomass and disturbed ionic status in both genotypes, Pusa 2002 was more salt tolerant and ensured higher AM fungal colonization, plant biomass and nutrient content with favourable ion status under salinity. Although all AM fungi reduced negative effects of salt stress, R. irregularis (alone or in combination with F. mosseae) displayed highest efficiency under salinity, resulting in highest biomass, yield, nutrient uptake and improved membrane stability with favourable K(+)/Na(+) and Ca(2+)/Na(+) ratios in the host plant. Higher effectiveness of R. irregularis correlated with higher root colonization, indicating that the symbiosis formed by R. irregularis had more stable viability and efficiency under salt stress. These findings enhance understanding of the functional diversity of AM fungi in ameliorating plant salt stress tolerance and suggest the potential use of R. irregularis for increasing Cajanus cajan productivity in saline soils.

  9. Effects of enhanced soil P on photosynthesis, root respiration and nutrient uptake of Artemisia tridentata in different photosynthetic photon flux densities and CO[sub 2] conditions

    SciTech Connect

    Cui, M.; Caldwell, M.M. )

    1994-06-01

    Responses of leaf photosynthesis, root respiration and P uptake by Artemisia tridentata seedlings to study root physiological adjustments to utilize available nutrient resources in a changing soil environment. Root respiration was measured for intact root systems in split-root chambers. Increasing P in 0.2 [times] Hoagland's solution from 0.04 mmol to 2.0 mmol increased leaf photosynthesis by 6% in 3 days, increased nighttime leaf respiration rate by 8% and root respiration by 18%. After PPFD was reduced from 800 to 200 [mu]mol m[sup [minus]2]s[sup [minus]1] leaf photosynthesis deceased by 67%, and root respiration by 26% in the following day but then decreased by 35% over the next three days. Shading may limit root growth and nutrient uptake by lowering the carbohydrate supply to root systems.

  10. Uptake of radioiodide by Paenibacillus sp., Pseudomonas sp., Burkholderia sp. and Rhodococcus sp. isolated from a boreal nutrient-poor bog.

    PubMed

    Lusa, Merja; Lehto, Jukka; Aromaa, Hanna; Knuutinen, Jenna; Bomberg, Malin

    2016-06-01

    Radionuclides, like radioiodine ((129)I), may escape deep geological nuclear waste repositories and migrate to the surface ecosystems. In surface ecosystems, microorganisms can affect their movement. Iodide uptake of six bacterial strains belonging to the genera Paenibacillus, Pseudomonas, Burkholderia and Rhodococcus isolated from an acidic boreal nutrient-poor bog was tested. The tests were run in four different growth media at three temperatures. All bacterial strains removed iodide from the solution with the highest efficiency shown by one of the Paenibacillus strains with >99% of iodide removed from the solution in one of the used growth media. Pseudomonas, Rhodococcus and one of the two Paenibacillus strains showed highest iodide uptake in 1% yeast extract with maximum values for the distribution coefficient (Kd) ranging from 90 to 270L/kg DW. The Burkholderia strain showed highest uptake in 1% Tryptone (maximum Kd 170L/kg DW). The Paenibacillus strain V0-1-LW showed exceptionally high uptake in 0.5% peptone +0.25% yeast extract broth (maximum Kd>1,000,000L/kg DW). Addition of 0.1% glucose to the 0.5% peptone +0.25% yeast extract broth reduced iodide uptake at 4°C and 20°C and enhanced iodide uptake at 37°C compared to the uptake without glucose. This indicates that the uptake of glucose and iodide may be competing processes in these bacteria. We estimated that in in situ conditions of the bog, the bacterial uptake of iodide accounts for approximately 0.1%-0.3% of the total sorption of iodide in the surface, subsurface peat, gyttja and clay layers.

  11. Basalt Weathering, Nutrient Uptake, And Carbon Release By An Exotic And A Native Arizona Grass Species Under Different Temperature Conditions

    NASA Astrophysics Data System (ADS)

    Gallas, G.; Dontsova, K.; Chorover, J.; Hunt, E.; Ravi, S.

    2010-12-01

    basalt weathering. All of the leachate samples showed higher pH than the input water, and the pH was elevated in treatments that contained grass. This indicated that in the presence of vegetation there was more proton absorption. The trends in total nitrogen concentrations indicate a dependence on temperature; the same can be said of anion concentrations. Anion leaching is lower at higher temperatures possibly due to greater plant uptake. Both organic and inorganic carbon concentrations were found to be higher in grass treatments than in control treatments. Because both dissolved CO2 and soluble organic exudates encourage mineral dissolution, this could be causative of the weathering enhancements observed. Denudation of nutrient elements differed between plant species and between temperatures, possibly relating to plant uptake and secondary mineral formation. This study gives unique insight into plant-mineral interactions as a function of plant species and temperature that is essential for understanding Earth systems under changing climate.

  12. Effects of biochar and nitrogen addition on nutrient and Cd uptake of Cichorium intybus grown in acidic soil.

    PubMed

    Xiao, Yan; Li, Yang; Che, Yeye; Deng, Shaojun; Liu, Mohan

    2017-09-26

    Biochar is an organic amendment used for soil remediation, there are only a few studies documenting the effects of nitrogen on the role of biochar in contaminated soils. A pot experiment was conducted to investigate the impacts of biochar (0%, 1% and 2.5%, w/w) and nitrogen (0, 100 and 200 mg N kg(-1)) on plant growth, nutrient and Cd uptake of Cichorium intybus. N, P, Ca, Mg and Cd concentrations increased with N level in 0 and 1% biochar treatments. In plants treated with 2.5% biochar, 200 mg N kg(-1) addition caused significant reductions of N, P, Ca, Mg and Cd concentrations in comparison to 100 mg N kg(-1) treatments. Nitrogen promoted shoot biomass at all biochar treatments, while biochar had no effect on shoot biomass in 0 and 200 mg N kg(-1) addition treatments. Nitrogen also significantly increased N, P, K, Ca, Mg and Cd contents in the 0 and 1.5% biochar addition treatments. Although soil DTPA-extractable Cd concentration showed the lowest values in 1% biochar in combination with 100 and 200 mg N kg(-1) addition treatments, lowest shoot Cd concentration and relatively high shoot biomass occurred in the 2.5% biochar + 200 mg N kg(-1) treatment. Based on these results, biochar application at its highest rate (2.5%) in combination with high N supply (200 mg N kg(-1)) contributed to both crop yield and agricultural product safety. N input alone might increase the risk of human health, and the optimum N dose should be determined during phytostabilization process.

  13. Plant root-driven hydraulic redistribution, root nutrient uptake and carbon exudation interact with soil properties to generate rhizosphere resource hotspots that vary in space and time

    NASA Astrophysics Data System (ADS)

    Espeleta, J. F.; Neumann, R. B.; Cardon, Z. G.; Mayer, K. U.; Rastetter, E. B.

    2014-12-01

    Hydraulic redistribution (HR) of soil water by plants occurs in seasonally dry ecosystems worldwide. During drought, water flows from deep moist soil, through plant roots, into dry (often litter-rich) upper soil layers. Using modeling, we explored how physical transport processes driven by transpiration and hydraulic redistribution interact with root physiology (nutrient uptake and carbon exudation) and soil properties (soil texture and cation exchange) to influence nitrogen and carbon concentrations in the rhizosphere. At the single root scale, we modeled a 10-cm radial soil domain, and simulated solute transport, soil cation exchange, and root exudation and nutrient uptake under two water flow patterns: daytime transpiration without nighttime HR, and daytime transpiration with nighttime HR. During HR, water efflux flushed solutes away from the root, diluting the concentrations of key nutrients like nitrate. The transport of cations by transpiration in the day and their accumulation near the root led to competitive desorption of ammonium from soil further from the root and generation of hotspots of ammonium availability at night. HR influenced the spatial and temporal patterns of these hotspots and their intensity. They were also influenced by soil properties of texture and cation exchange capacity. This dynamic resource landscape caused by diel cycling between transpiration and hydraulic redistribution presents a stage for greater complexity of microbial interactions. We are currently embedding a microbial community and small food web into this rhizosphere model in order to explore how organisms responsible for nutrient and soil carbon cycling respond to these fluctuating resource regimes.

  14. Improving Urban Stormwater Runoff Quality by Nutrient Removal through Floating Treatment Wetlands and Vegetation Harvest.

    PubMed

    Xu, Bing; Wang, Xue; Liu, Jia; Wu, Jiaqiang; Zhao, Yongjun; Cao, Weixing

    2017-08-01

    Two floating treatment wetlands (FTWs) in experimental tanks were compared in terms of their effectiveness on removing nutrients. The results showed that the FTWs were dominated by emergent wetland plants and were constructed to remove nutrients from simulated urban stormwater. Iris pseudacorus and Thalia dealbata wetland systems were effective in reducing the nutrient. T. dealbata FTWs showed higher nutrient removal performance than I. pseudacorus FTWs. Nitrogen (N) and phosphorous (P) removal rates in water by T. dealbata FTWs were 3.95 ± 0.19 and 0.15 ± 0.01 g/m(2)/day, respectively. For I. pseudacorus FTWs, the TN and TP removal rates were 3.07 ± 0.15 and 0.14 ± 0.01 g/m(2)/day, respectively. The maximum absolute growth rate for T. dealbata corresponded directly with the maximum mean nutrient removal efficiency during the 5th stage. At harvest, N and P uptak of T. dealbata was 23.354 ± 1.366 g and 1.489 ± 0.077 g per plant, respectively, approximate twice as high as by I. pseudacorus.

  15. Is nutrient uptake by plant roots sensitive to the rate of mass flow? Reappraisal of an old chestnut for spatially distributed root systems

    NASA Astrophysics Data System (ADS)

    McMurtrie, R. E.; Näsholm, T.

    2015-12-01

    Numerous modelling papers have considered the contribution of mass flow to nutrient uptake by a single plant root, but few have evaluated its contribution at the scale of an entire root system. We derive equations for nitrogen (N) influx per unit root surface area (J) and N uptake by a single root (U) as functions of soil nitrogen supply, root-length density (RLD) and the velocity of water at the root surface (vo). This model of N uptake by a single root can be used to evaluate N uptake by an entire root system if spatial distributions are known for soil N supply, root biomass and water-uptake velocity. In this paper we show that spatial distributions of RLD and vo can be estimated simultaneously under an optimisation hypothesis (MaxNup, McMurtrie et al. 2012), according to which total root mass and total water uptake are distributed vertically in order to maximise total N uptake. The MaxNup hypothesis leads to equations for optimal vertical profiles of RLD, vo, J and U, maximum rooting depth and the fraction of total available soil nitrogen taken up by the root system. Predicted values of vo are enhanced at depths where nitrogen influx per unit root surface area (J) is more sensitive to vo and diminished at depths where J is less sensitive to vo. Predicted vo is largest at the base of the root system where RLD is lowest, and is smallest in upper soil layers where RLD is highest. MaxNup thus predicts that water uptake will be distributed preferentially to soil depths where it will enhance nitrogen uptake U; this tendency will amplify the sensitivity of total N uptake to total water uptake, compared with strategies where vo is the same for all roots, or where vo is elevated for roots in upper soil layers. Reference McMurtrie RE, Iversen CM, Dewar RC, Medlyn BE, Näsholm T, Pepper DA, Norby RJ. 2012. Plant root distributions and nitrogen uptake predicted by a hypothesis of optimal root foraging. Ecology and Evolution 2: 1235-1250.

  16. Improvement of aquaponic performance through micro- and macro-nutrient addition.

    PubMed

    Ru, Dongyun; Liu, Jikai; Hu, Zhen; Zou, Yina; Jiang, Liping; Cheng, Xiaodian; Lv, Zhenting

    2017-07-01

    Aquaponics is one of the "zero waste" industry in the twenty-first century, and is considered to be one of the major trends for the future development of agriculture. However, the low nitrogen utilization efficiency (NUE) restricted its widely application. To date, many attempts have been conducted to improve its NUE. In the present study, effect of micro- and macro-nutrient addition on performance of tilapia-pak choi aquaponics was investigated. Results showed that the addition of micro- and macro-nutrients improved the growth of plant directly and facilitated fish physiology indirectly, which subsequently increased NUE of aquaponics from 40.42 to 50.64%. In addition, remarkable lower total phosphorus concentration was obtained in aquaponics with micro- and macro-nutrient addition, which was attributed to the formation of struvite. Most of the added micro-nutrients were enriched in plant root, while macro-nutrients mainly existed in water. Moreover, no enrichment of micro- and macro-nutrients in aquaponic products (i.e., fish and plant leaves) was observed, indicating that it had no influence on food safety. The findings here reported manifest that appropriate addition of micro- and macro-nutrients to aquaponics is necessary, and would improve its economic feasibility.

  17. Can computer-based feedback improve emergency department patient uptake of rapid HIV screening?

    PubMed

    Merchant, Roland C; Clark, Melissa A; Langan, Thomas J; Mayer, Kenneth H; Seage, George R; DeGruttola, Victor G

    2011-07-01

    We determine whether (1) an audiocomputer-delivered tailored feedback intervention increases emergency department (ED) patient uptake of opt-in, nontargeted rapid HIV screening; and (2) uptake is greater among patients who report more HIV risk and among those whose self-perceived HIV risk increases from baseline after completion of an HIV risk assessment. ED patients aged 18 to 64 years were randomly assigned to receive either an assessment about reported and self-perceived HIV risk or an identical assessment plus feedback about their risk for having or acquiring an HIV infection, tailored according to their reported risk. All participants were offered a fingerstick rapid HIV test. Two-sample tests of binomial proportions were used to compare screening uptake by study arm. Multivariable logistic regression was used to assess the relationship of reported HIV risk and an increase in self-perceived HIV risk with uptake of HIV screening. Of the 566 participants, the median age was 29 years, 62.2% were women, and 66.9% previously had been tested for HIV. Uptake of HIV screening was similar in the intervention and no intervention arms (54.1% versus 55.5% [Δ=-0.01%; 95% confidence interval {CI} -0.09% to 0.07%]). An increase in self-perceived HIV risk predicted greater uptake of HIV screening for women (odds ratio 2.15; 95% CI 1.08 to 4.28) but not men (odds ratio 1.61; 95% CI 0.60 to 4.30). Uptake of HIV screening was not related to reported HIV risk. Uptake of rapid HIV screening in the ED was not improved by this feedback intervention. Other methods need to be investigated to improve uptake of HIV screening by ED patients. Copyright © 2011. Published by Mosby, Inc.

  18. Assessing Interventions To Improve Influenza Vaccine Uptake Among Health Care Workers.

    PubMed

    Rashid, Harunor; Yin, Jiehui Kevin; Ward, Kirsten; King, Catherine; Seale, Holly; Booy, Robert

    2016-02-01

    Despite official recommendations for health care workers to receive the influenza vaccine, uptake remains low. This systematic review of randomized controlled trials was conducted to understand the evidence about interventions to improve influenza vaccine uptake among health care workers. We identified twelve randomized controlled trials that, collectively, assessed six major categories of interventions involving 193,924 health care workers in high-income countries. The categories were educational materials and training sessions, improved access to the vaccine, rewards following vaccination, organized efforts to raise vaccine awareness, reminders to get vaccinated, and the use of lead advocates for vaccination. Only one of the four studies that evaluated the effect of a single intervention in isolation demonstrated a significantly higher vaccine uptake rate in the intervention group, compared to controls. However, five of the eight studies that evaluated a combination of strategies showed significantly higher vaccine uptake. Despite the low quality of the studies identified, the data suggest that combined interventions can moderately increase vaccine uptake among health care workers. Further methodologically appropriate trials of combined interventions tailored to individual health care settings and incorporating less-studied strategies would enhance the evidence about interventions to improve immunization uptake among health care workers.

  19. Regulation of 2,4-epibrassinolide on mineral nutrient uptake and ion distribution in Ca(NO3)2 stressed cucumber plants.

    PubMed

    Yuan, Lingyun; Zhu, Shidong; Shu, Sheng; Sun, Jin; Guo, Shirong

    2015-09-01

    2,4-Epibrassinolide (EBL) is a plant hormone that plays a pivotal role in regulation of plants growth and development processes under abiotic stress. The investigation was carried out to study the effect of EBL on mineral nutrients uptake and distribution with ion element analysis and X-ray microanalysis in cucumber seedlings (Cucumis sativus L. cv. Jinyou No.4) under 80 mM Ca(NO3)2 stress. Our study found EBL significantly alleviated the inhibitory of P, K, Na, Mg, Fe, Mn, or Cl uptake in shoot or root by Ca(NO3)2 stress. Under Ca(NO3)2 stress, X-ray microanalysis showed that high levels of Ca by EBL treatment accumulated in the epidermal cells of root and gradually decreased from epidermal cells to stellar parenchyma. K(+) levels were restored in different cross section of roots and high K(+) level mostly accumulated in stellar parenchyma. The results of Ca(2+) ultra-structural localization showed Ca(2+) particles of antimonite precipitate by EBL were partly decreased in mesophyll and root cells, and Ca(2+) precipitate distributed in intercellular spaces again. Increased Ca(2+)-ATPase activity and ATP content by EBL were also contributed to extrude excess Ca(2+) from the cytoplasm. These results suggested that EBL could alleviate the ion damage from excess Ca(2+) through regulating mineral nutrients uptake and distribution. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. A Multi-Agency Nutrient Dataset Used to Estimate Loads, Improve Monitoring Design, and Calibrate Regional Nutrient SPARROW Models

    USGS Publications Warehouse

    Saad, D.A.; Schwarz, G.E.; Robertson, D.M.; Booth, N.L.

    2011-01-01

    Stream-loading information was compiled from federal, state, and local agencies, and selected universities as part of an effort to develop regional SPAtially Referenced Regressions On Watershed attributes (SPARROW) models to help describe the distribution, sources, and transport of nutrients in streams throughout much of the United States. After screening, 2,739 sites, sampled by 73 agencies, were identified as having suitable data for calculating long-term mean annual nutrient loads required for SPARROW model calibration. These sites had a wide range in nutrient concentrations, loads, and yields, and environmental characteristics in their basins. An analysis of the accuracy in load estimates relative to site attributes indicated that accuracy in loads improve with increases in the number of observations, the proportion of uncensored data, and the variability in flow on observation days, whereas accuracy declines with increases in the root mean square error of the water-quality model, the flow-bias ratio, the number of days between samples, the variability in daily streamflow for the prediction period, and if the load estimate has been detrended. Based on compiled data, all areas of the country had recent declines in the number of sites with sufficient water-quality data to compute accurate annual loads and support regional modeling analyses. These declines were caused by decreases in the number of sites being sampled and data not being entered in readily accessible databases. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

  1. Long-term reductions in anthropogenic nutrients link to improvements in Chesapeake Bay habitat

    USGS Publications Warehouse

    Ruhl, H.; Rybicki, N.B.

    2010-01-01

    Great effort continues to focus on ecosystem restoration and reduction of nutrient inputs thought to be responsible, in part, for declines in estuary habitats worldwide. The ability of environmental policy to address restoration is limited, in part, by uncertainty in the relationships between costly restoration and benefits. Here, we present results from an 18-y field investigation (1990-2007) of submerged aquatic vegetation (SAV) community dynamics and water quality in the Potomac River, a major tributary of the Chesapeake Bay. River and anthropogenic discharges lower water clarity by introducing nutrients that stimulate phytoplankton and epiphyte growth as well as suspended sediments. Efforts to restore the Chesapeake Bay are often viewed as failing. Overall nutrient reduction and SAV restoration goals have not been met. In the Potomac River, however, reduced in situ nutrients, wastewater-treatment effluent nitrogen, and total suspended solids were significantly correlated to increased SAV abundance and diversity. Species composition and relative abundance also correlated with nutrient and water-quality conditions, indicating declining fitness of exotic species relative to native species during restoration. Our results suggest that environmental policies that reduce anthropogenic nutrient inputs do result in improved habitat quality, with increased diversity and native species abundances. The results also help elucidate why SAV cover has improved only in some areas of the Chesapeake Bay.

  2. Long-term reductions in anthropogenic nutrients link to improvements in Chesapeake Bay habitat.

    PubMed

    Ruhl, Henry A; Rybicki, Nancy B

    2010-09-21

    Great effort continues to focus on ecosystem restoration and reduction of nutrient inputs thought to be responsible, in part, for declines in estuary habitats worldwide. The ability of environmental policy to address restoration is limited, in part, by uncertainty in the relationships between costly restoration and benefits. Here, we present results from an 18-y field investigation (1990-2007) of submerged aquatic vegetation (SAV) community dynamics and water quality in the Potomac River, a major tributary of the Chesapeake Bay. River and anthropogenic discharges lower water clarity by introducing nutrients that stimulate phytoplankton and epiphyte growth as well as suspended sediments. Efforts to restore the Chesapeake Bay are often viewed as failing. Overall nutrient reduction and SAV restoration goals have not been met. In the Potomac River, however, reduced in situ nutrients, wastewater-treatment effluent nitrogen, and total suspended solids were significantly correlated to increased SAV abundance and diversity. Species composition and relative abundance also correlated with nutrient and water-quality conditions, indicating declining fitness of exotic species relative to native species during restoration. Our results suggest that environmental policies that reduce anthropogenic nutrient inputs do result in improved habitat quality, with increased diversity and native species abundances. The results also help elucidate why SAV cover has improved only in some areas of the Chesapeake Bay.

  3. Long-term reductions in anthropogenic nutrients link to improvements in Chesapeake Bay habitat

    PubMed Central

    Rybicki, Nancy B.

    2010-01-01

    Great effort continues to focus on ecosystem restoration and reduction of nutrient inputs thought to be responsible, in part, for declines in estuary habitats worldwide. The ability of environmental policy to address restoration is limited, in part, by uncertainty in the relationships between costly restoration and benefits. Here, we present results from an 18-y field investigation (1990–2007) of submerged aquatic vegetation (SAV) community dynamics and water quality in the Potomac River, a major tributary of the Chesapeake Bay. River and anthropogenic discharges lower water clarity by introducing nutrients that stimulate phytoplankton and epiphyte growth as well as suspended sediments. Efforts to restore the Chesapeake Bay are often viewed as failing. Overall nutrient reduction and SAV restoration goals have not been met. In the Potomac River, however, reduced in situ nutrients, wastewater-treatment effluent nitrogen, and total suspended solids were significantly correlated to increased SAV abundance and diversity. Species composition and relative abundance also correlated with nutrient and water-quality conditions, indicating declining fitness of exotic species relative to native species during restoration. Our results suggest that environmental policies that reduce anthropogenic nutrient inputs do result in improved habitat quality, with increased diversity and native species abundances. The results also help elucidate why SAV cover has improved only in some areas of the Chesapeake Bay. PMID:20823243

  4. Improving General Intelligence with a Nutrient-Based Pharmacological Intervention

    ERIC Educational Resources Information Center

    Stough, Con; Camfield, David; Kure, Christina; Tarasuik, Joanne; Downey, Luke; Lloyd, Jenny; Zangara, Andrea; Scholey, Andrew; Reynolds, Josh

    2011-01-01

    Cognitive enhancing substances such as amphetamine and modafinil have become popular in recent years to improve acute cognitive performance particularly in environments in which enhanced cognition or intelligence is required. Nutraceutical nootropics, which are natural substances that have the ability to bring about acute or chronic changes in…

  5. Improving General Intelligence with a Nutrient-Based Pharmacological Intervention

    ERIC Educational Resources Information Center

    Stough, Con; Camfield, David; Kure, Christina; Tarasuik, Joanne; Downey, Luke; Lloyd, Jenny; Zangara, Andrea; Scholey, Andrew; Reynolds, Josh

    2011-01-01

    Cognitive enhancing substances such as amphetamine and modafinil have become popular in recent years to improve acute cognitive performance particularly in environments in which enhanced cognition or intelligence is required. Nutraceutical nootropics, which are natural substances that have the ability to bring about acute or chronic changes in…

  6. Transcriptomic Analysis of Compromise Between Air-Breathing and Nutrient Uptake of Posterior Intestine in Loach (Misgurnus anguillicaudatus), an Air-Breathing Fish.

    PubMed

    Huang, Songqian; Cao, Xiaojuan; Tian, Xianchang

    2016-08-01

    Dojo loach (Misgurnus anguillicaudatus) is an air-breathing fish species by using its posterior intestine to breathe on water surface. So far, the molecular mechanism about accessory air-breathing in fish is seldom addressed. Five cDNA libraries were constructed here for loach posterior intestines form T01 (the initial stage group), T02 (mid-stage of normal group), T03 (end stage of normal group), T04 (mid-stage of air-breathing inhibited group), and T05 (the end stage of air-breathing inhibited group) and subjected to perform RNA-seq to compare their transcriptomic profilings. A total of 92,962 unigenes were assembled, while 37,905 (40.77 %) unigenes were successfully annotated. 2298, 1091, and 3275 differentially expressed genes (fn1, ACE, EGFR, Pxdn, SDF, HIF, VEGF, SLC2A1, SLC5A8 etc.) were observed in T04/T02, T05/T03, and T05/T04, respectively. Expression levels of many genes associated with air-breathing and nutrient uptake varied significantly between normal and intestinal air-breathing inhibited group. Intraepithelial capillaries in posterior intestines of loaches from T05 were broken, while red blood cells were enriched at the surface of intestinal epithelial lining with 241 ± 39 cells per millimeter. There were periodic acid-schiff (PAS)-positive epithelial mucous cells in posterior intestines from both normal and air-breathing inhibited groups. Results obtained here suggested an overlap of air-breathing and nutrient uptake function of posterior intestine in loach. Intestinal air-breathing inhibition in loach would influence the posterior intestine's nutrient uptake ability and endothelial capillary structure stability. This study will contribute to our understanding on the molecular regulatory mechanisms of intestinal air-breathing in loach.

  7. Inter-laboratory study to improve the quality of the analysis of nutrients in rainwater chemistry

    NASA Astrophysics Data System (ADS)

    Karthikeyan, Sathrugnan; Balasubramanian, Rajasekhar; He, Jun

    This paper describes the results of an inter-laboratory study conducted for the analysis of nutrients (nitrate, ammonium, phosphate, total nitrogen (TN), and total phosphorus (TP)) in natural rainwater. For this purpose, rainwater samples were collected and aggregated in Singapore and homogenized. These samples were immediately filtered through 0.45 μm membrane filters and autoclaved for 15 min at 80 °C in order to stabilize the nutrients. The homogeneity and the stability of nutrients were rigorously tested for a period of three months initially. Upon ensuring the homogeneity and stability, the samples were distributed to 15 different laboratories from various countries around the world (Australia, Brazil, India, Mauritius, Singapore, Slovenia, Spain, Taiwan, and USA). Almost all laboratories have reported the analytical results for nitrate whereas only 8 of the 15 laboratories reported results for other nutrients such as ammonium, phosphate, TN, and TP. The discrepancy was mainly due to the presence of these nutrients in low concentration levels (particularly ammonium ion and phosphate). Not all the laboratories were equipped with analytical capabilities to conduct the analysis of nutrients in low concentration levels. Further, the uncertainty associated with the analysis of TN and TP restricted the number of laboratories that could report their analytical data on nutrients. All 14 laboratories reported nitrate-nitrogen results which were in good agreement with each other (0.68 ± 0.07 mg l -1). Similarly, the results of TN and TP were also comparable among at least 8 laboratories. This inter-laboratory study on the analysis of nutrients in natural rainwater, conducted for the first time, provided an opportunity to the participating laboratories to assess and improve their laboratory performance, thereby, improving the quality of their analytical data.

  8. Interaction of Eu(III) with mammalian cells: Cytotoxicity, uptake, and speciation as a function of Eu(III) concentration and nutrient composition.

    PubMed

    Sachs, Susanne; Heller, Anne; Weiss, Stephan; Bok, Frank; Bernhard, Gert

    2015-10-01

    In case of the release of lanthanides and actinides into the environment, knowledge about their behavior in biological systems is necessary to assess and prevent adverse health effects for humans. We investigated the interaction of europium with FaDu cells (human squamous cell carcinoma cell line) combining analytical methods, spectroscopy, and thermodynamic modeling with in-vitro cell experiments under defined conditions. Both the cytotoxicity of Eu(III) onto FaDu cells and its cellular uptake are mainly concentration-dependent. Moreover, they are governed by its chemical speciation in the nutrient medium. In complete cell culture medium, i.e., in the presence of fetal bovine serum, Eu(III) is stabilized in solution in a wide concentration range by complexation with serum proteins resulting in low cytotoxicity and cellular Eu(III) uptake. In serum-free medium, Eu(III) precipitates as hardly soluble phosphate species, exhibiting a significantly higher cytotoxicity and slightly higher cellular uptake. The presence of a tenfold excess of citrate in serum-free medium causes the formation of Eu(HCit)2(3-) complexes in addition to the dominating Eu(III) phosphate species, resulting in a decreased Eu(III) cytotoxicity and cellular uptake. The results of this study underline the crucial role of a metal ion's speciation for its toxicity and bioavailability.

  9. Combined effect of ultraviolet-B radiation and cadmium contamination on nutrient uptake and photosynthetic pigments in Brassica campestris L. seedlings.

    PubMed

    Shukla, U C; Murthy, R C; Kakkar, P

    2008-12-01

    Environmental and industrial pollution along with increase in ground level UV-B radiation, because of stratospheric ozone depletion, present multiple stresses, which may affect crop photosynthesis and productivity. The present study was undertaken to see interactive effects of heavy metal contamination (Cd(2+)) and UV-B exposure on essential nutrient (Ca(2+), Mg(2+), K(+)) uptake, biomass, and chlorophyll content in mustard (Brassica campestris L.) seedlings. Plants grown in 0.5, 1.0, 2.5, and 5.0 mg L(-1) Cd(2+) supplemented medium were exposed to UV-B for 30 min (0.4 mW cm(-2)) per day. The interactive effect of two stresses measured after 5 and 10 days showed an overall decline in biomass. Under dual stress (5 mg Cd(2+) L(-1)) significant (P < 0.001) decrease in chlorophyll a (43%), chlorophyll b (23%), and carotenoid (53%) was observed. Ca(2+) uptake was reduced by 51% in roots under high doses of Cd(2+) (5 mg L(-1)) and simultaneous exposure to 0.4 mW cm(-2) UV-B for 10 days. Mg(2+) content was reduced by 48% and K(+) by 62% under similar exposure conditions. Decline in nutrient uptake in Brassica campestris L. seedlings was observed both in root and shoot leaf in the initial growth period under controlled lab conditions. Cadmium ion (Cd(2+)) uptake was significantly enhanced by 33% (P < 0.001) in the presence of UV-B. The findings are significant as multiple stress conditions prevalent in the environment play an important role during the early growth period, a period critical for crop yield. 2008 Wiley Periodicals, Inc.

  10. Comparison of mineral weathering and biomass nutrient uptake in two small forested watersheds underlain by quartzite bedrock, Catoctin Mountain, Maryland, USA

    USGS Publications Warehouse

    Rice, Karen; Price, Jason R.

    2014-01-01

    To quantify chemical weathering and biological uptake, mass-balance calculations were performed on two small forested watersheds located in the Blue Ridge Physiographic Province in north-central Maryland, USA. Both watersheds, Bear Branch (BB) and Fishing Creek Tributary (FCT), are underlain by relatively unreactive quartzite bedrock. Such unreactive bedrock and associated low chemical-weathering rates offer the opportunity to quantify biological processes operating within the watershed. Hydrologic and stream-water chemistry data were collected from the two watersheds for the 9-year period from June 1, 1990 to May 31, 1999. Of the two watersheds, FCT exhibited both higher chemical-weathering rates and biomass nutrient uptake rates, suggesting that forest biomass aggradation was limited by the rate of chemical weathering of the bedrock. Although the chemical-weathering rate in the FCT watershed was low relative to the global average, it masked the influence of biomass base-cation uptake on stream-water chemistry. Any differences in bedrock mineralogy between the two watersheds did not exert a significant influence on the overall weathering stoichiometry. The difference in chemical-weathering rates between the two watersheds is best explained by a larger proportion of reactive phyllitic layers within the bedrock of the FCT watershed. Although the stream gradient of BB is about two-times greater than that of FCT, its influence on chemical weathering appears to be negligible. The findings of this study support the biomass nutrient uptake stoichiometry of K1.0Mg1.1Ca0.97 previously determined for the study site. Investigations of the chemical weathering of relatively unreactive quartzite bedrock may provide insight into critical zone processes.

  11. Dynamics of plant nutrients, utilization and uptake, and soil microbial community in crops under ambient and elevated carbon dioxide

    USDA-ARS?s Scientific Manuscript database

    In natural settings such as under field conditions, the plant available soil nutrients in conjunction with other environmental factors such as, solar radiation, temperature, precipitation, and atmospheric carbon dioxide (CO2) concentration determine crop adaptation and productivity. Therefore, crop...

  12. Microbial fertilizer improving the soil nutrients and growth of reed in degraded wetland

    NASA Astrophysics Data System (ADS)

    Sun, W. L.; Zhao, Y. G.; Yang, M.

    2017-06-01

    Wetland degradation is frequently observed in some river estuaries of China due to the imbalance of soil nutrient. In order to improve the soil nutrient and promote the restoration of plant, the microbial fertilizer containing the phosphorus-dissolving strain Pseudomonas plecoglossicida and potassium-dissolving strain Bacillus aryabhattai was developed to stimulate the growth of plant and increase soil nutrient in this study. Results showed that microbial fertilizer was more effective in increasing the contents of total N, P and K in soil and the activities of soil sucrase and urease. Compared with the control, the height and dry weight of reeds were increased 53.13% and 59.31%; the activities of soil sucrase and urease were improved 41.25% and 39.57%. Illumina Miseq sequencing showed that Pseudomonas spp. were the most predominant in microbial fertilizer treated soil but other treatments were quite different. Hence, the microbial fertilizer significantly promoted the growth of reed, increased soil nutrient and enzyme activity. It consequently revealed a promising application in improving the wetland soil nutrients and ecological restoration.

  13. Systematic review of interventions to improve patient uptake and completion of pulmonary rehabilitation in COPD

    PubMed Central

    Jones, Arwel W.; Taylor, Abigail; Gowler, Holly; O'Kelly, Noel; Ghosh, Sudip; Bridle, Christopher

    2017-01-01

    Pulmonary rehabilitation is considered a key management strategy for chronic obstructive pulmonary disease (COPD), but its effectiveness is undermined by poor patient uptake and completion. The aim of this review was to identify, select and synthesise the available evidence on interventions for improving uptake and completion of pulmonary rehabilitation in COPD. Electronic databases and trial registers were searched for randomised trials evaluating the effect of an intervention compared with a concurrent control group on patient uptake and completion. The primary outcomes were the number of participants who attended a baseline assessment and at least one session of pulmonary rehabilitation (uptake), and the number of participants who received a discharge assessment (completion). Only one quasi-randomised study (n=115) (of 2468 records identified) met the review inclusion criteria and was assessed as having a high risk of bias. The point estimate of effect did, however, indicate greater programme completion and attendance rates in participants allocated to pulmonary rehabilitation plus a tablet computer (enabled with support for exercise training) compared with controls (pulmonary rehabilitation only). There is insufficient evidence to guide clinical practice on interventions for improving patient uptake and completion of pulmonary rehabilitation in COPD. Despite increasing awareness of patient barriers to pulmonary rehabilitation, our review highlights the existing under-appreciation of interventional trials in this area. This knowledge gap should be viewed as an area of research priority due to its likely impact in undermining wider implementation of pulmonary rehabilitation and restricting patient access to a treatment considered the cornerstone of COPD. PMID:28154821

  14. Systematic review of interventions to improve patient uptake and completion of pulmonary rehabilitation in COPD.

    PubMed

    Jones, Arwel W; Taylor, Abigail; Gowler, Holly; O'Kelly, Noel; Ghosh, Sudip; Bridle, Christopher

    2017-01-01

    Pulmonary rehabilitation is considered a key management strategy for chronic obstructive pulmonary disease (COPD), but its effectiveness is undermined by poor patient uptake and completion. The aim of this review was to identify, select and synthesise the available evidence on interventions for improving uptake and completion of pulmonary rehabilitation in COPD. Electronic databases and trial registers were searched for randomised trials evaluating the effect of an intervention compared with a concurrent control group on patient uptake and completion. The primary outcomes were the number of participants who attended a baseline assessment and at least one session of pulmonary rehabilitation (uptake), and the number of participants who received a discharge assessment (completion). Only one quasi-randomised study (n=115) (of 2468 records identified) met the review inclusion criteria and was assessed as having a high risk of bias. The point estimate of effect did, however, indicate greater programme completion and attendance rates in participants allocated to pulmonary rehabilitation plus a tablet computer (enabled with support for exercise training) compared with controls (pulmonary rehabilitation only). There is insufficient evidence to guide clinical practice on interventions for improving patient uptake and completion of pulmonary rehabilitation in COPD. Despite increasing awareness of patient barriers to pulmonary rehabilitation, our review highlights the existing under-appreciation of interventional trials in this area. This knowledge gap should be viewed as an area of research priority due to its likely impact in undermining wider implementation of pulmonary rehabilitation and restricting patient access to a treatment considered the cornerstone of COPD.

  15. Growth and nitrogen uptake by Salicornia europaea and Aster tripolium in nutrient conditions typical of aquaculture wastewater.

    PubMed

    Quintã, R; Santos, R; Thomas, D N; Le Vay, L

    2015-02-01

    The increasing need for environmentally sound aquaculture development can, in part, be addressed by using halophytic plants in integrated multitrophic aquaculture systems (IMTA) to remove waste dissolved nitrogen (N). However, knowledge of plant ability to take up nitrogen is of foremost importance to predict plants performance in such systems. Two species, Salicornia europaea and Aster tripolium, have been identified as potential candidates for IMTA due to their salt tolerance, potential N removal capabilities and their high commercial value as an additional crop. This study investigated the growth and N uptake rates of these two species under different N supply (NH4(+), NO3(-), NH4NO3). S. europaea plants produced a lower biomass when grown in NH4(+) compared to NO3(-) or NH4NO3, while A. tripolium biomass was not affected by the form in which N was supplied. N uptake in plants incubated at different concentrations of (15)N enriched solution (up to 2 mmol l(-1)) fitted the Michaelis-Menten model. While S. europaea NH4-N maximum uptake did not differ between starved and non-starved plants, A. tripolium NH4-N uptake was higher in starved plants when supplied alone. When NO3(-) was supplied alone, NO3-N maximum uptake was lower, for both species, when the plants were not starved. Comparison of starved and non-starved plants N uptake demonstrates the need for cautious interpretation of N uptake rates across different conditions. According to the observed results, both S. europaea and A. tripolium are capable of significantly high biomass production and N removal making them potential species for inclusion in efficient IMTA. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Challenges to Improving the Uptake of Milk in a Nursery Class: A Case Study

    ERIC Educational Resources Information Center

    Albon, Deborah

    2009-01-01

    Purpose: The purpose of this paper is to examine why the uptake of free milk in a particular nursery class was low, to explore the meanings children attribute to drinks given to them in school and those brought from home, and make suggestions as to what might be done to improve children's intake of free school milk. Design/methodology/approach:…

  17. Challenges to Improving the Uptake of Milk in a Nursery Class: A Case Study

    ERIC Educational Resources Information Center

    Albon, Deborah

    2009-01-01

    Purpose: The purpose of this paper is to examine why the uptake of free milk in a particular nursery class was low, to explore the meanings children attribute to drinks given to them in school and those brought from home, and make suggestions as to what might be done to improve children's intake of free school milk. Design/methodology/approach:…

  18. Phytoremediation to remove nutrients and improve eutrophic stormwaters using water lettuce (Pistia stratiotes L.).

    PubMed

    Lu, Qin; He, Zhenli L; Graetz, Donald A; Stoffella, Peter J; Yang, Xiaoe

    2010-01-01

    Water quality impairment by nutrient enrichment from agricultural activities has been a concern worldwide. Phytoremediation technology using aquatic plants in constructed wetlands and stormwater detention ponds is increasingly applied to remediate eutrophic waters. The objectives of this study were to evaluate the effectiveness and potential of water lettuce (Pistia stratiotes L.) in removing nutrients including nitrogen (N) and phosphorus (P) from stormwater in the constructed water detention systems before it is discharged into the St. Lucie Estuary, an important surface water system in Florida, using phytoremediation technologies. In this study, water lettuce (P. stratiotes) was planted in the treatment plots of two stormwater detention ponds (East and West Ponds) in 2005-2007 and water samples from both treatment and control plots were weekly collected and analyzed for water quality properties including pH, electrical conductivity, turbidity, suspended solids, and nutrients (N and P). Optimum plant density was maintained and plant samples were collected monthly and analyzed for nutrient contents. Water quality in both ponds was improved, as evidenced by decreases in water turbidity, suspended solids, and nutrient concentrations. Water turbidity was decreased by more than 60%. Inorganic N (NH(4) (+) and NO(3) (-)) concentrations in treatment plots were more than 50% lower than those in control plots (without plant). Reductions in both PO(4) (3-) and total P were approximately 14-31%, as compared to the control plots. Water lettuce contained average N and P concentrations of 17 and 3.0 g kg(-1), respectively, and removed 190-329 kg N ha(-1) and 25-34 kg P ha(-1) annually. Many aquatic plants have been used to remove nutrients from eutrophic waters but water lettuce proved superior to most other plants in nutrient removal efficiency, owing to its rapid growth and high biomass yield potential. However, the growth and nutrient removal potential are affected by many

  19. Effects of anaerobic growth conditions on biomass accumulation, root morphology, and efficiencies of nutrient uptake and utilization in seedlings of some southern coastal plain

    SciTech Connect

    Topa, M.A.

    1984-01-01

    Seedlings of pond, and loblolly pines were grown in a non-circulating, continuously-flowing solution culture under anaerobic (0.75 mg/1 O/sub 2/) conditions to determine the effects of anaerobiosis on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with morphological changes which enhanced root internal aeration. Oxygen transport from shoot to the root was demonstrated via rhizosphere oxidation experiments using indigo-carmine dye solutions and polarography. Stem and root collar lenticels were found to be the major sites of atmospheric O/sub 2/ entry for submerged roots. Longitudinal and radial pathways for gas diffusion via intercellular spaces in the pericycle and ray parenchyma, respectively, were elucidated histologically. Lenticel and aerenchyma development, and rhizosphere oxidation in roots of anaerobically-grown sand pine seedlings were minimal. Elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term /sup 32/P uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass. Phosphorus absorption rates were negatively correlated with internal tissue phosphorus concentrations, and root and shoot biomass. 315 refs., 25 figs., 14 tabs.

  20. Silicon improves salt tolerance by increasing root water uptake in Cucumis sativus L.

    PubMed

    Zhu, Yong-Xing; Xu, Xuan-Bin; Hu, Yan-Hong; Han, Wei-Hua; Yin, Jun-Liang; Li, Huan-Li; Gong, Hai-Jun

    2015-09-01

    Silicon enhances root water uptake in salt-stressed cucumber plants through up-regulating aquaporin gene expression. Osmotic adjustment is a genotype-dependent mechanism for silicon-enhanced water uptake in plants. Silicon can alleviate salt stress in plants. However, the mechanism is still not fully understood, and the possible role of silicon in alleviating salt-induced osmotic stress and the underlying mechanism still remain to be investigated. In this study, the effects of silicon (0.3 mM) on Na accumulation, water uptake, and transport were investigated in two cucumber (Cucumis sativus L.) cultivars ('JinYou 1' and 'JinChun 5') under salt stress (75 mM NaCl). Salt stress inhibited the plant growth and photosynthesis and decreased leaf transpiration and water content, while added silicon ameliorated these negative effects. Silicon addition only slightly decreased the shoot Na levels per dry weight in 'JinYou 1' but not in 'JinChun 5' after 10 days of stress. Silicon addition reduced stress-induced decreases in root hydraulic conductivity and/or leaf-specific conductivity. Expressions of main plasma membrane aquaporin genes in roots were increased by added silicon, and the involvement of aquaporins in water uptake was supported by application of aquaporin inhibitor and restorative. Besides, silicon application decreased the root xylem osmotic potential and increased root soluble sugar levels in 'JinYou 1.' Our results suggest that silicon can improve salt tolerance of cucumber plants through enhancing root water uptake, and silicon-mediated up-regulation of aquaporin gene expression may in part contribute to the increase in water uptake. In addition, osmotic adjustment may be a genotype-dependent mechanism for silicon-enhanced water uptake in plants.

  1. Cooking Schools Improve Nutrient Intake Patterns of People with Type 2 Diabetes

    ERIC Educational Resources Information Center

    Archuleta, Martha; VanLeeuwen, Dawn; Halderson, Karen; Jackson, K'Dawn; Bock, Margaret Ann; Eastman, Wanda; Powell, Jennifer; Titone, Michelle; Marr, Carol; Wells, Linda

    2012-01-01

    Objective: To determine whether cooking classes offered by the Cooperative Extension Service improved nutrient intake patterns in people with type 2 diabetes. Design: Quasi-experimental using pretest, posttest comparisons. Setting: Community locations including schools, churches, and senior centers. Participants: One hundred seventeen people with…

  2. Cooking Schools Improve Nutrient Intake Patterns of People with Type 2 Diabetes

    ERIC Educational Resources Information Center

    Archuleta, Martha; VanLeeuwen, Dawn; Halderson, Karen; Jackson, K'Dawn; Bock, Margaret Ann; Eastman, Wanda; Powell, Jennifer; Titone, Michelle; Marr, Carol; Wells, Linda

    2012-01-01

    Objective: To determine whether cooking classes offered by the Cooperative Extension Service improved nutrient intake patterns in people with type 2 diabetes. Design: Quasi-experimental using pretest, posttest comparisons. Setting: Community locations including schools, churches, and senior centers. Participants: One hundred seventeen people with…

  3. Improving uptake of influenza vaccination among older people: a randomised controlled trial.

    PubMed Central

    Arthur, Antony J; Matthews, Ruth J; Jagger, Carol; Clarke, Michael; Hipkin, Alison; Bennison, Dean P

    2002-01-01

    BACKGROUND: The uptake of influenza vaccination among older people is suboptimal. Contact with a doctor or nurse is associated with older people deciding to accept influenza vaccination. AIM: To compare different forms of approach in improving uptake of influenza vaccination among patients aged 75 years and over in primary care. DESIGN OF STUDY: Randomised controlled trial. SETTING: One large rural general practice serving the town and surrounding area of Melton Mowbray, Leicestershire. METHOD: All 2,052 patients aged 75 years and over, registered with the practice and not living in nursing/residential homes or sheltered accommodation, were included in the study. One-third of patients were randomised to receive an offer of influenza vaccination as part of an over-75 health check administered by a practice nurse in the patient's home, and two-thirds of patients were randomised to receive a personal letter of invitation to attend an influenza vaccination clinic held at the surgery. The main outcome measure was uptake of influenza vaccination. RESULTS: Six hundred and eighty patients were randomised to the health check arm of the trial and 1,372 were randomised to receive a personal letter. Of those randomised to the health check arm, 468 received the health check from the nurse. Overall, the difference in influenza vaccination uptake was 6.4% (95% confidence interval [CI] = 2.2% to 10.4%) with 67.9% (n = 932) of those who were sent a personal letter actually receiving the vaccine, compared with 74.3% (n = 505) of those offered a combined health check and influenza vaccination (P = 0.003). CONCLUSION: Combining home-based over- 75 health checks with influenza vaccination can improve uptake among older patients. However this intervention is likely to be costly and its effect on influenza vaccination rates is modest. The difference in uptake is greater among those who do not routinely comeforwardfor vaccination and a more viable option may be to target these patients

  4. Improving uptake of influenza vaccination among older people: a randomised controlled trial.

    PubMed

    Arthur, Antony J; Matthews, Ruth J; Jagger, Carol; Clarke, Michael; Hipkin, Alison; Bennison, Dean P

    2002-09-01

    The uptake of influenza vaccination among older people is suboptimal. Contact with a doctor or nurse is associated with older people deciding to accept influenza vaccination. To compare different forms of approach in improving uptake of influenza vaccination among patients aged 75 years and over in primary care. Randomised controlled trial. One large rural general practice serving the town and surrounding area of Melton Mowbray, Leicestershire. All 2,052 patients aged 75 years and over, registered with the practice and not living in nursing/residential homes or sheltered accommodation, were included in the study. One-third of patients were randomised to receive an offer of influenza vaccination as part of an over-75 health check administered by a practice nurse in the patient's home, and two-thirds of patients were randomised to receive a personal letter of invitation to attend an influenza vaccination clinic held at the surgery. The main outcome measure was uptake of influenza vaccination. Six hundred and eighty patients were randomised to the health check arm of the trial and 1,372 were randomised to receive a personal letter. Of those randomised to the health check arm, 468 received the health check from the nurse. Overall, the difference in influenza vaccination uptake was 6.4% (95% confidence interval [CI] = 2.2% to 10.4%) with 67.9% (n = 932) of those who were sent a personal letter actually receiving the vaccine, compared with 74.3% (n = 505) of those offered a combined health check and influenza vaccination (P = 0.003). Combining home-based over- 75 health checks with influenza vaccination can improve uptake among older patients. However this intervention is likely to be costly and its effect on influenza vaccination rates is modest. The difference in uptake is greater among those who do not routinely comeforwardfor vaccination and a more viable option may be to target these patients.

  5. The Effect of Catchment Urbanization on Nutrient Uptake and Biofilm Enzyme Activity in Lake Superior (USA) Tributary Streams

    EPA Science Inventory

    We used landscape, habitat, and chemistry variables, along with nutrient spiraling metrics and biofilm extracellular enzyme activity (EEA), to assess the response of streams to the level of urbanization within their catchments. For this study nine streams of similar catchment are...

  6. The Effect of Catchment Urbanization on Nutrient Uptake and Biofilm Enzyme Activity in Lake Superior (USA) Tributary Streams

    EPA Science Inventory

    We used landscape, habitat, and chemistry variables, along with nutrient spiraling metrics and biofilm extracellular enzyme activity (EEA), to assess the response of streams to the level of urbanization within their catchments. For this study nine streams of similar catchment are...

  7. Nutrient uptake and community metabolism in streams draining harvested and old-growth watersheds: A preliminary assessment

    Treesearch

    Brian H. Hill; Frank H. McCormick

    2004-01-01

    The effect of timber harvesting on streams is assessed using two measures of ecosystem function: nutrient spiraling and community metabolism. This research is being conducted in streams of the southern Appalachian Mountains of North Carolina, the Ouachita Mountains of Arkansas, the Cascade Mountains of Oregon, and the redwood forests of northern California, in order to...

  8. Lay health educators within primary care practices to improve cancer screening uptake for South Asian patients: challenges in quality improvement

    PubMed Central

    Lofters, AK; Vahabi, M; Prakash, V; Banerjee, L; Bansal, P; Goel, S; Dunn, S

    2017-01-01

    Background Cancer screening uptake is known to be low among South Asian residents of Ontario. The objective of this pilot study was to determine if lay health educators embedded within the practices of primary care providers could improve willingness to screen and cancer screening uptake for South Asian patients taking a quality improvement approach. Materials and methods Participating physicians selected quality improvement initiatives to use within their offices that they felt could increase willingness to screen and cancer screening uptake. They implemented initiatives, adapting as necessary, for six months. Results Four primary care physicians participated in the study. All approximated that at least 60% of their patients were of South Asian ethnicity. All physicians chose to work with a preexisting lay health educator program geared toward South Asians. Health ambassadors spoke to patients in the office and telephoned patients. For all physicians, ~60% of South Asian patients who were overdue for cancer screening and who spoke directly to health ambassadors stated they were willing to be screened. One physician was able to track actual screening among contacted patients and found that screening uptake was relatively high: from 29.2% (colorectal cancer) to 44.6% (breast cancer) of patients came in for screening within six months of the first phone calls. Although physicians viewed the health ambassadors positively, they found the study to be time intensive and resource intensive, especially as this work was additional to usual clinical duties. Discussion Using South Asian lay health educators embedded within primary care practices to telephone patients in their own languages showed promise in this study to increase awareness about willingness to screen and cancer screening uptake, but it was also time intensive and resource intensive with numerous challenges. Future quality improvement efforts should further develop the phone call invitation process, as well as

  9. Silicate mineral impacts on the uptake and storage of arsenic and plant nutrients in rice ( Oryza sativa L.).

    PubMed

    Seyfferth, Angelia L; Fendorf, Scott

    2012-12-18

    Arsenic-contaminated rice grain may threaten human health globally. Since H₃AsO₃⁰ is the predominant As species found in paddy pore-waters, and H₄SiO₄⁰ and H₃AsO₃⁰ share an uptake pathway, silica amendments have been proposed to decrease As uptake and consequent As concentrations in grains. Here, we evaluated the impact of two silicate mineral additions differing in solubility (+Si(L), diatomaceous earth, 0.29 mM Si; +Si(H), Si-gel, 1.1 mM Si) to soils differing in mineralogy on arsenic concentration in rice. The +Si(L) addition either did not change or decreased As concentration in pore-water but did not change or increased grain-As levels relative to the (+As--Si) control. The +Si(H) addition increased As in pore-water, but it significantly decreased grain-As relative to the (+As--Si) control. Only the +Si(H) addition resulted in significant increases in straw- and husk-Si. Total grain- and straw-As was negatively correlated with pore-water Si, and the relationship differed between two soils exhibiting different mineralogy. These differing results are a consequence of competition between H₄SiO₄⁰ and H₃AsO₃⁰ for adsorption sites on soil solids and subsequent plant-uptake, and illustrate the importance of Si mineralogy on arsenic uptake.

  10. Using extension phosphorus uptake research to improve Idaho's nutrient management planning program

    USDA-ARS?s Scientific Manuscript database

    Irrigated silage corn is the main crop used for phosphorus removal; however little is known about the actual amounts of phosphorus removed under southern Idaho growing conditions. The purpose of this study was to survey phosphorus removal by irrigated corn grown for silage in southern Idaho under va...

  11. Understanding nitrate uptake, signaling and remobilisation for improving plant nitrogen use efficiency.

    PubMed

    Kant, Surya

    2017-08-28

    The majority of terrestrial plants use nitrate as their main source of nitrogen. Nitrate also acts as an important signalling molecule in vital physiological processes required for optimum plant growth and development. Improving nitrate uptake and transport, through activation by nitrate sensing, signalling and regulatory processes, would enhance plant growth, resulting in improved crop yields. The increased remobilisation of nitrate, and assimilated nitrogenous compounds, from source to sink tissues further ensures higher yields and quality. An updated knowledge of various transporters, genes, activators, and microRNAs, involved in nitrate uptake, transport, remobilisation, and nitrate-mediated root growth, is presented. An enhanced understanding of these components will allow for their orchestrated fine tuning in efforts to improving nitrogen use efficiency in plants. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Habib, Shaid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz

    2010-01-01

    As required by the Harmful Algal Bloom and Hypoxia Research Control Act of 1998, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force issued the 2001 Gulf Hypoxia Action Plan (updated in 2008). In response to the Gulf Hypoxia Action Plan of 2001 (updated in 2008), the EPA Gulf of Mexico Hypoxia Modeling and Monitoring Project has established a detailed model for the Mississippi-Attchafalaya River Basin which provides a capability to forecast the multi-source nutrient loading to the Gulf and the subsequent bio-geochemical processes leading to hypoxic conditions and subsequent effects on Gulf habitats and fisheries. The primary purpose of the EPA model is to characterize the impacts of nutrient management actions, or proposed actions on the spatial and temporal characteristics of the Gulf hypoxic zone. The model is expected to play a significant role in determining best practices and improved strategies for incentivizing nutrient reduction strategies, including installation of on-farm structures to reduce sediment and nutrient runoff, use of cover crops and other agricultural practices, restoration of wetlands and riparian buffers, improved waste water treatment and decreased industrial nitrogen emissions. These decisions are currently made in a fragmented way by federal, state, and local agencies, using a variety of small scale models and limited data. During the past three years, EPA has collected an enormous amount of in-situ data to be used in the model. We believe that the use of NASA satellite data products in the model and for long term validation of the model has the potential to significantly increase the accuracy and therefore the utility of the model for the decision making described above. This proposal addresses the Gulf of Mexico Alliance (GOMA) priority issue of reductions in nutrient inputs to coastal ecosystem. It further directly relates to water quality for healthy beaches and shellfish beds and wetland and coastal conservation

  13. Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Habib, Shaid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz

    2010-01-01

    As required by the Harmful Algal Bloom and Hypoxia Research Control Act of 1998, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force issued the 2001 Gulf Hypoxia Action Plan (updated in 2008). In response to the Gulf Hypoxia Action Plan of 2001 (updated in 2008), the EPA Gulf of Mexico Hypoxia Modeling and Monitoring Project has established a detailed model for the Mississippi-Attchafalaya River Basin which provides a capability to forecast the multi-source nutrient loading to the Gulf and the subsequent bio-geochemical processes leading to hypoxic conditions and subsequent effects on Gulf habitats and fisheries. The primary purpose of the EPA model is to characterize the impacts of nutrient management actions, or proposed actions on the spatial and temporal characteristics of the Gulf hypoxic zone. The model is expected to play a significant role in determining best practices and improved strategies for incentivizing nutrient reduction strategies, including installation of on-farm structures to reduce sediment and nutrient runoff, use of cover crops and other agricultural practices, restoration of wetlands and riparian buffers, improved waste water treatment and decreased industrial nitrogen emissions. These decisions are currently made in a fragmented way by federal, state, and local agencies, using a variety of small scale models and limited data. During the past three years, EPA has collected an enormous amount of in-situ data to be used in the model. We believe that the use of NASA satellite data products in the model and for long term validation of the model has the potential to significantly increase the accuracy and therefore the utility of the model for the decision making described above. This proposal addresses the Gulf of Mexico Alliance (GOMA) priority issue of reductions in nutrient inputs to coastal ecosystem. It further directly relates to water quality for healthy beaches and shellfish beds and wetland and coastal conservation

  14. Ocean nutrients

    NASA Astrophysics Data System (ADS)

    Boyd, Philip W.; Hurd, Catriona L.

    Nutrients provide the chemical life-support system for phytoplankton in the ocean. Together with the carbon fixed during photosynthesis, nutrients provide the other elements, such as N and P, needed to synthesize macromolecules to build cellular constituents such as ribosomes. The makeup of these various biochemicals, such as proteins, pigments, and nucleic acids, together determine the elemental stoichiometry of an individual phytoplankton cell. The stoichiometry of different phytoplankton species or groups will vary depending on the proportions of distinct cellular machinery, such as for growth or resource acquisition, they require for their life strategies. The uptake of nutrients by phytoplankton helps to set the primary productivity, and drives the biological pump, of the global ocean. In the case of nitrogen, the supply of nutrients is categorized as either new or regenerated. The supply of new nitrogen, such as nitrate upwelled from the ocean' interior or biological nitrogen fixation, is equal to the vertical export of particular organic matter from the upper ocean on a timescale of years. Nutrients such as silica can also play a structural role in some phytoplankton groups, such as diatoms, where they are used to synthesize a siliceous frustule that offers some mechanical protection from grazers. In this chapter, we also explore nutrient uptake kinetics, patterns in nutrient distributions in space and time, the biogeochemical cycle of nitrogen, the atmospheric supply of nutrients, departures from the Redfield ratio, and whether nutrient distributions and cycling will be altered in the future

  15. Improving the uptake of systematic reviews: a systematic review of intervention effectiveness and relevance

    PubMed Central

    Wallace, John; Byrne, Charles; Clarke, Mike

    2014-01-01

    Objective Little is known about the barriers, facilitators and interventions that impact on systematic review uptake. The objective of this study was to identify how uptake of systematic reviews can be improved. Selection criteria Studies were included if they addressed interventions enhancing the uptake of systematic reviews. Reports in any language were included. All decisionmakers were eligible. Studies could be randomised trials, cluster-randomised trials, controlled-clinical trials and before-and-after studies. Data sources We searched 19 databases including PubMed, EMBASE and The Cochrane Library, covering the full range of publication years from inception to December 2010. Two reviewers independently extracted data and assessed quality according to the Effective Practice and Organisation of Care criteria. Results 10 studies from 11 countries, containing 12 interventions met our criteria. Settings included a hospital, a government department and a medical school. Doctors, nurses, mid-wives, patients and programme managers were targeted. Six of the studies were geared to improving knowledge and attitudes while four targeted clinical practice. Synthesis of results Three studies of low-to-moderate risk of bias, identified interventions that showed a statistically significant improvement: educational visits, short summaries of systematic reviews and targeted messaging. Promising interventions include e-learning, computer-based learning, inactive workshops, use of knowledge brokers and an e-registry of reviews. Juxtaposing barriers and facilitators alongside the identified interventions, it was clear that the three effective approaches addressed a wide range of barriers and facilitators. Discussion A limited number of studies were found for inclusion. However, the extensive literature search is one of the strengths of this review. Conclusions Targeted messaging, educational visits and summaries are recommended to enhance systematic review uptake. Identified

  16. Mineral nutrient uptake from prey and glandular phosphatase activity as a dual test of carnivory in semi-desert plants with glandular leaves suspected of carnivory

    PubMed Central

    Płachno, Bartosz Jan; Adamec, Lubomír; Huet, Hervé

    2009-01-01

    Background and Aims Ibicella lutea and Proboscidea parviflora are two American semi-desert species of glandular sticky plants that are suspected of carnivory as they can catch small insects. The same characteristics might also hold for two semi-desert plants with glandular sticky leaves from Israel, namely Cleome droserifolia and Hyoscyamus desertorum. The presence of proteases on foliar hairs, either secreted by the plant or commensals, detected using a simple test, has long been considered proof of carnivory. However, this test does not prove whether nutrients are really absorbed from insects by the plant. To determine the extent to which these four species are potentially carnivorous, hair secretion of phosphatases and uptake of N, P, K and Mg from fruit flies as model prey were studied in these species and in Roridula gorgonias and Drosophyllum lusitanicum for comparison. All species examined possess morphological and anatomical adaptations (hairs or emergences secreting sticky substances) to catch and kill small insects. Methods The presence of phosphatases on foliar hairs was tested using the enzyme-labelled fluorescence method. Dead fruit flies were applied to glandular sticky leaves of experimental plants and, after 10–15 d, mineral nutrient content in their spent carcasses was compared with initial values in intact flies after mineralization. Key Results Phosphatase activity was totally absent on Hyoscyamus foliar hairs, a certain level of activity was usually found in Ibicella, Proboscidea and Cleome, and a strong response was found in Drosophyllum. Roridula exhibited only epidermal activity. However, only Roridula and Drosophyllum took up nutrients (N, P, K and Mg) from applied fruit flies. Conclusions Digestion of prey and absorption of their nutrients are the major features of carnivory in plants. Accordingly, Roridula and Drosophyllum appeared to be fully carnivorous; by contrast, all other species examined are non-carnivorous as they did not meet

  17. Distinctive expansion of gene families associated with plant cell wall degradation, secondary metabolism, and nutrient uptake in the genomes of grapevine trunk pathogens.

    PubMed

    Morales-Cruz, Abraham; Amrine, Katherine C H; Blanco-Ulate, Barbara; Lawrence, Daniel P; Travadon, Renaud; Rolshausen, Philippe E; Baumgartner, Kendra; Cantu, Dario

    2015-06-19

    Trunk diseases threaten the longevity and productivity of grapevines in all viticulture production systems. They are caused by distantly-related fungi that form chronic wood infections. Variation in wood-decay abilities and production of phytotoxic compounds are thought to contribute to their unique disease symptoms. We recently released the draft sequences of Eutypa lata, Neofusicoccum parvum and Togninia minima, causal agents of Eutypa dieback, Botryosphaeria dieback and Esca, respectively. In this work, we first expanded genomic resources to three important trunk pathogens, Diaporthe ampelina, Diplodia seriata, and Phaeomoniella chlamydospora, causal agents of Phomopsis dieback, Botryosphaeria dieback, and Esca, respectively. Then we integrated all currently-available information into a genome-wide comparative study to identify gene families potentially associated with host colonization and disease development. The integration of RNA-seq, comparative and ab initio approaches improved the protein-coding gene prediction in T. minima, whereas shotgun sequencing yielded nearly complete genome drafts of Dia. ampelina, Dip. seriata, and P. chlamydospora. The predicted proteomes of all sequenced trunk pathogens were annotated with a focus on functions likely associated with pathogenesis and virulence, namely (i) wood degradation, (ii) nutrient uptake, and (iii) toxin production. Specific patterns of gene family expansion were described using Computational Analysis of gene Family Evolution, which revealed lineage-specific evolution of distinct mechanisms of virulence, such as specific cell wall oxidative functions and secondary metabolic pathways in N. parvum, Dia. ampelina, and E. lata. Phylogenetically-informed principal component analysis revealed more similar repertoires of expanded functions among species that cause similar symptoms, which in some cases did not reflect phylogenetic relationships, thereby suggesting patterns of convergent evolution. This study

  18. Effects of a controlled-release fertilizer on yield, nutrient uptake, and fertilizer usage efficiency in early ripening rapeseed (Brassica napus L.)*

    PubMed Central

    Tian, Chang; Zhou, Xuan; Liu, Qiang; Peng, Jian-wei; Wang, Wen-ming; Zhang, Zhen-hua; Yang, Yong; Song, Hai-xing; Guan, Chun-yun

    2016-01-01

    Background: Nitrogen (N), phosphorous (P), and potassium (K) are critical nutrient elements necessary for crop plant growth and development. However, excessive inputs will lead to inefficient usage and cause excessive nutrient losses in the field environment, and also adversely affect the soil, water and air quality, human health, and biodiversity. Methods: Field experiments were conducted to study the effects of controlled-release fertilizer (CRF) on seed yield, plant growth, nutrient uptake, and fertilizer usage efficiency for early ripening rapeseed (Xiangzayou 1613) in the red-yellow soil of southern China during 2011–2013. It was grown using a soluble fertilizer (SF) and the same amounts of CRF, such as SF1/CRF1 (3750 kg/hm2), SF2/CRF2 (3000 kg/hm2), SF3/CRF3 (2250 kg/hm2), SF4/CRF4 (1500 kg/hm2), SF5/CRF5 (750 kg/hm2), and also using no fertilizer (CK). Results: CRF gave higher seed yields than SF in both seasons by 14.51%. CRF4 and SF3 in each group achieved maximum seed yield (2066.97 and 1844.50 kg/hm2, respectively), followed by CRF3 (1929.97 kg/hm2) and SF4 (1839.40 kg/hm2). There were no significant differences in seed yield among CK, SF1, and CRF1 (P>0.05). CRF4 had the highest profit (7126.4 CNY/hm2) and showed an increase of 12.37% in seed yield, and it decreased by 11.01% in unit fertilizer rate compared with SF4. The branch number, pod number, and dry matter weight compared with SF increased significantly under the fertilization of CRF (P<0.05). The pod number per plant was the major contributor to seed yield. On the other hand, the N, P, and K uptakes increased at first and then decreased with increasing the fertilizer rate at maturity, and the N, P, and K usage efficiency decreased with increasing the fertilizer rate. The N, P, and K uptakes and usage efficiencies of the CRF were significantly higher than those of SF (P<0.05). The N accumulation and N usage efficiency of CRF increased by an average of 13.66% and 9.74 percentage points

  19. Effects of a controlled-release fertilizer on yield, nutrient uptake, and fertilizer usage efficiency in early ripening rapeseed (Brassica napus L.).

    PubMed

    Tian, Chang; Zhou, Xuan; Liu, Qiang; Peng, Jian-Wei; Wang, Wen-Ming; Zhang, Zhen-Hua; Yang, Yong; Song, Hai-Xing; Guan, Chun-Yun

    Nitrogen (N), phosphorous (P), and potassium (K) are critical nutrient elements necessary for crop plant growth and development. However, excessive inputs will lead to inefficient usage and cause excessive nutrient losses in the field environment, and also adversely affect the soil, water and air quality, human health, and biodiversity. Field experiments were conducted to study the effects of controlled-release fertilizer (CRF) on seed yield, plant growth, nutrient uptake, and fertilizer usage efficiency for early ripening rapeseed (Xiangzayou 1613) in the red-yellow soil of southern China during 2011-2013. It was grown using a soluble fertilizer (SF) and the same amounts of CRF, such as SF1/CRF1 (3750 kg/hm(2)), SF2/CRF2 (3000 kg/hm(2)), SF3/CRF3 (2250 kg/hm(2)), SF4/CRF4 (1500 kg/hm(2)), SF5/CRF5 (750 kg/hm(2)), and also using no fertilizer (CK). CRF gave higher seed yields than SF in both seasons by 14.51%. CRF4 and SF3 in each group achieved maximum seed yield (2066.97 and 1844.50 kg/hm(2), respectively), followed by CRF3 (1929.97 kg/hm(2)) and SF4 (1839.40 kg/hm(2)). There were no significant differences in seed yield among CK, SF1, and CRF1 (P>0.05). CRF4 had the highest profit (7126.4 CNY/hm(2)) and showed an increase of 12.37% in seed yield, and it decreased by 11.01% in unit fertilizer rate compared with SF4. The branch number, pod number, and dry matter weight compared with SF increased significantly under the fertilization of CRF (P<0.05). The pod number per plant was the major contributor to seed yield. On the other hand, the N, P, and K uptakes increased at first and then decreased with increasing the fertilizer rate at maturity, and the N, P, and K usage efficiency decreased with increasing the fertilizer rate. The N, P, and K uptakes and usage efficiencies of the CRF were significantly higher than those of SF (P<0.05). The N accumulation and N usage efficiency of CRF increased by an average of 13.66% and 9.74 percentage points, respectively, compared

  20. [Effects of nitrogen, phosphorus and potassium fertilizers on the yield, quality and nutrient uptake of Pulsatilla cernua].

    PubMed

    Wan, Run-lan; Li, Hai-yan; Zhang, Wu-qu; Piao, Zhong-yun

    2013-11-01

    To study the effects of nitrogen (N), phosphorus (P2O5) and potassium (K2O) fertilizers on the growth, yield total saponins content and nutrient absorption of Pulsatilla cernua and provide a theoretical basis for good agriculture practice. Field plot experiments was conducted, based on the D-saturation optimal design with three factors of nitrogen, phosphorus and potassium. Samples collected periodically were used for determination the contents of nutrient and total saponins, and for measurement of yield and agronomic characters. Nutrient contents in Pulsatilla cernua varied with growth stage and part under the same growth stage. Nutrient contents in aerial part were higher than that in root, while the proportion of nutritional absorption from seedling stage to the middle growth stage was larger than that at the late growth stage. Yield and total saponins content of Pulsatilla cernua were significantly influenced by the N1P2O5 and K2O applications, among three factors, N had the greatest effects, the next was K2O and P5O2. Pulsatilla cerntua under field cultivation should be fertilized properly, top-dressing with these fertilizers during the early growth stage and increasing the proportion of potassium. According to total saponin production of Pulsatilla cernua, the optimum fertilization model for high yield and good quality is 180 kg/hm2 of N, 79.74 kg/hm2 of P2O5, and 225 kg/hm2 of K20, with a N : P2O : K2O ratio of approximately 2.3 : 1 : 2.8.

  1. Sensory active piperine analogues from Macropiper excelsum and their effects on intestinal nutrient uptake in Caco-2 cells.

    PubMed

    Obst, Katja; Lieder, Barbara; Reichelt, Katharina V; Backes, Michael; Paetz, Susanne; Geißler, Katrin; Krammer, Gerhard; Somoza, Veronika; Ley, Jakob P; Engel, Karl-Heinz

    2017-03-01

    The phytochemical profile of Macropiper excelsum (G.Forst.) Miq. subsp. excelsum (Piperaceae), a shrub which is widespread in New Zealand, was investigated by LC-MS-guided isolation and characterization via HR-ESI-TOF-MS and NMR spectroscopy. The isolated compounds were sensorily evaluated to identify their contribution to the overall taste of the crude extract with sweet, bitter, herbal and trigeminal impressions. Besides the known non-volatile Macropiper compounds, the lignans (+)-diayangambin and (+)-excelsin, four further excelsin isomers, (+)-diasesartemin, (+)-sesartemin, (+)-episesartemin A and B were newly characterized. Moreover, piperine and a number of piperine analogues as well as trans-pellitorine and two homologues, kalecide and (2E,4E)-tetradecadienoic acid N-isobutyl amide were identified in M. excelsum, some of them for the first time. Methyl(2E,4E)-7-(1,3-benzodioxol-5-yl)hepta-2,4-dienoate was identified and characterized for the first time in nature. Sensory analysis of the pure amides indicated that they contributed to the known chemesthetic effects of Macropiper leaves and fruits. Since the pungent piperine has been shown to affect glucose and fatty acid metabolism in vivo in previous studies, piperine itself and four of the isolated compounds, piperdardine, chingchengenamide A, dihydropiperlonguminine, and methyl(2E,4E)-7-(1,3-benzodioxol-5-yl)hepta-2,4-dienoate, were investigated regarding their effects on glucose and fatty acid uptake by enterocyte-like Caco-2 cells, in concentrations ranging from 0.1 to 100 μM. Piperdardine showed the most pronounced effect, with glucose uptake increased by 83 ± 18% at 100 μM compared to non-treated control cells. An amide group seems to be advantageous for glucose uptake stimulation, but not necessarily for fatty acid uptake-stimulating effects of piperine-related compounds.

  2. L-Proline uptake in Saccharomyces cerevisiae mitochondria can contribute to bioenergetics during nutrient stress as alternative mitochondrial fuel.

    PubMed

    Pallotta, Maria Luigia

    2014-01-01

    L-Proline (pyrrolidine-2-carboxylic acid) is a distinctive metabolite both biochemically and biotechnologically and is currently recognized to have a cardinal role in gene expression and cellular signaling pathways in stress response. Proline-fueled mitochondrial metabolism involves the oxidative conversion of L-Proline to L-Glutamate in two enzymatic steps by means of Put1p and Put2p that help Saccharomyces cerevisiae to respond to changes in the nutritional environment by initiating the breakdown of L-Proline as a source for nitrogen, carbon, and energy. Compartmentalization of L-Proline catabolic pathway implies that extensive L-Proline transport must take place between the cytosol where its biogenesis via Pro1p, Pro2p, Pro3p occurs and mitochondria. L-Proline uptake in S. cerevisiae purified and active mitochondria was investigated by swelling experiments, oxygen uptake and fluorimetric measurement of a membrane potential generation (ΔΨ). Our results strongly suggest that L-Proline uptake occurs via a carried-mediated process as demonstrated by saturation kinetics and experiments with N-ethylmaleimide, a pharmacological compound that is a cysteine-modifying reagent in hydrophobic protein domains and that inhibited mitochondrial transport. Plasticity of S. cerevisiae cell biochemistry according to background fluctuations is an important factor of adaptation to stress. Thus L-Proline → Glutamate route feeds Krebs cycle providing energy and anaplerotic carbon for yeast survival.

  3. Functional traits and structural controls on the relationship between photosynthetic CO2 uptake and sun-induced fluorescence in a Mediterranean grassland under different nutrient availability

    NASA Astrophysics Data System (ADS)

    Migliavacca, Mirco

    2016-04-01

    Recent studies have shown how human induced nitrogen (N) and phosphorous (P) imbalances affect essential ecosystem processes, and might be particularly important in water-limited ecosystems. Hyperspectral information can be used to directly infer nutrient-induced variation in structural and functional changes of vegetation under different nutrient availability. However, several uncertainties still hamper the direct link between photosynthetic CO2 uptake (gross primary productivity, GPP) and hyperspectral reflectance. Sun-induced fluorescence (SIF) provides a new non-invasive measurement approach that has the potential to quantify dynamic changes in light use efficiency and photosynthetic CO2 uptake. In this contribution we will present an experiment conducted in a Mediterranean grassland, where 16 plots of 8x8 meters were manipulated by adding nutrient (N, P, and NP). Almost simultaneous estimates of canopy scale GPP and SIF were conducted with transparent transient-state canopy chambers and high resolution spectrometers, respectively. We investigated the response of GPP and SIF to different nutrient availability and plant stoichiometry. The second objective was to identify how structural (LAI, leaf angle distribution, and biodiversity) and canopy biochemical properties (e.g. N and chlorophyll content - Chl) control the functional relationship between GPP and SIF. To test the different hypotheses the SCOPE radiative transfer model was used. We ran a factorial experiment with SCOPE to disentangle the main drivers (structure vs biochemistry) of the relationship GPP-SIF. The results showed significant differences in GPP values between N and without N addition plots. We also found that vegetation indices sensitive to pigment variations and physiology (such as photochemical reflectance index PRI) and SIF showed differences between different treatments. SCOPE showed very good agreement with the observed data (R2=0.71). The observed variability in SIF was mainly related

  4. Home-based HIV voluntary counselling and testing (VCT) for improving uptake of HIV testing.

    PubMed

    Bateganya, Moses; Abdulwadud, Omar A; Kiene, Susan M

    2010-07-07

    recommend large-scale implementation of home-based HIV testing. Further studies are needed to determine if home-based VCT is better than facility-based VCT in improving VCT uptake.

  5. Topical negative pressure improves autograft take by altering nutrient diffusion: A hypothesis.

    PubMed

    Wang, Xingang; Zhang, Yuanhai; Han, Chunmao

    2014-01-16

    The one-step surgical procedure for dermal substitutes combined with topical negative pressure (TNP) has proven effective for treating deep skin defects with improved graft take. The primary mechanism by which TNP improves autograft take is unknown. Some studies suggest that TNP promotes the rapid angiogenesis of dermal substitutes, improving graft take. However, at the early stage of one-step transplantation, the vascular system has not formed and imbibition is the main mode of nutrient supply. TNP can shorten the diffusion distance from the wound bed to the graft, leading to the timely renewal of the wound exudate via suction, removing any surplus exudate, and reducing tissue edema. In addition, TNP can regulate the local blood flow and inhibit bacterial colonization. Therefore, we hypothesized that TNP establishes a rapid balance between the nutrient supply to the wound bed and nutritional requirement of the graft via these pathways in the relatively closed, moist environment, improving autograft take. However, this balance could be affected by any negative pressure, intermittent or continuous. It is necessary to test this hypothesis in laboratory and clinical studies of the mode of nutrient supply in the imbibition phase and the change in exudate content.

  6. Differences in nutrient uptake capacity of the benthic filamentous algae Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. under varying N/P conditions.

    PubMed

    Liu, Junzhuo; Vyverman, Wim

    2015-03-01

    The N/P ratio of wastewater can vary greatly and directly affect algal growth and nutrient removal process. Three benthic filamentous algae species Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. were isolated from a periphyton bioreactor and cultured under laboratory conditions on varying N/P ratios to determine their ability to remove nitrate and phosphorus. The N/P ratio significantly influenced the algal growth and phosphorus uptake process. Appropriate N/P ratios for nitrogen and phosphorus removal were 5-15, 7-10 and 7-20 for Cladophora sp., Klebsormidium sp. and Pseudanabaena sp., respectively. Within these respective ranges, Cladophora sp. had the highest biomass production, while Pseudanabaena sp. had the highest nitrogen and phosphorus contents. This study indicated that Cladophora sp. had a high capacity of removing phosphorus from wastewaters of low N/P ratio, and Pseudanabaena sp. was highly suitable for removing nitrogen from wastewaters with high N/P ratio.

  7. Salicylic acid involved in the regulation of nutrient elements uptake and oxidative stress in Vallisneria natans (Lour.) Hara under Pb stress.

    PubMed

    Wang, Chao; Zhang, Songhe; Wang, Peifang; Hou, Jun; Qian, Jin; Ao, Yanhui; Lu, Jie; Li, Li

    2011-06-01

    In this study, the alterations in nutrient elements content, reactive oxygen species level and antioxidant response were studied in leaves of Vallisneria natans (Lour.) Hara exposed to salicylic acid (SA, 10 or 100 μM), or Pb (50 μM) or their combinations for 4d. No significant alterations in Mn and Ca content were observed but content of Cu, Zn, Fe and P decreased in plants exposed to SA alone. SA application inhibited the uptake of Pb and partially reversed Pb-induced the alterations in Mn, Ca and Fe content in leaves of V. natans exposed to 50 μM Pb. The decreased chlorophyll (a+b) and increased malondialdehyde and O(2-) and H(2)O(2) content were detected in plants exposed to 100 μM SA, 50 μM Pb, 10 μM SA+50 μM Pb or 100 μM SA+50 μM Pb. Application SA partially inhibited Pb-induced the increase of malondialdehyde, O(2-) and H(2)O(2) content. 100 μM SA decreased the activity of NADH oxidase and the content of non-protein thiols, carotenoids and ascorbic acid and increased the content of dehydroascorbate in plants treated with or without Pb. SA alone decreased the ascorbate peroxidase activity and increased the catalase and peroxidase activity, while SA application increased catalase activity but had no significant effect on ascorbate peroxidase and peroxidase activity in V. natans exposed to Pb. The results indicate that SA involves in the regulation of Pb uptake, nutrient balance and oxidative stress.

  8. Mycorrhizal phosphate uptake pathway in maize: vital for growth and cob development on nutrient poor agricultural and greenhouse soils

    PubMed Central

    Willmann, Martin; Gerlach, Nina; Buer, Benjamin; Polatajko, Aleksandra; Nagy, Réka; Koebke, Eva; Jansa, Jan; Flisch, René; Bucher, Marcel

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) form a mutually beneficial symbiosis with plant roots providing predominantly phosphorus in the form of orthophosphate (Pi) in exchange for plant carbohydrates on low P soils. The goal of this work was to generate molecular-genetic evidence in support of a major impact of the mycorrhizal Pi uptake (MPU) pathway on the productivity of the major crop plant maize under field and controlled conditions. Here we show, that a loss-of-function mutation in the mycorrhiza-specific Pi transporter gene Pht1;6 correlates with a dramatic reduction of above-ground biomass and cob production in agro-ecosystems with low P soils. In parallel mutant pht1;6 plants exhibited an altered fingerprint of chemical elements in shoots dependent on soil P availability. In controlled environments mycorrhiza development was impaired in mutant plants when grown alone. The presence of neighboring mycorrhizal nurse plants enhanced the reduced mycorrhiza formation in pht1;6 roots. Uptake of 33P-labeled orthophosphate via the MPU pathway was strongly impaired in colonized mutant plants. Moreover, repression of the MPU pathway resulted in a redirection of Pi to neighboring plants. In line with previous results, our data highlight the relevance of the MPU pathway in Pi allocation within plant communities and in particular the role of Pht1;6 for the establishment of symbiotic Pi uptake and for maize productivity and nutritional value in low-input agricultural systems. In a first attempt to identify cellular pathways which are affected by Pht1;6 activity, gene expression profiling via RNA-Seq was performed and revealed a set of maize genes involved in cellular signaling which exhibited differential regulation in mycorrhizal pht1;6 and control plants. The RNA data provided support for the hypothesis that fungal supply of Pi and/or Pi transport across Pht1;6 affects cell wall biosynthesis and hormone metabolism in colonized root cells. PMID:24409191

  9. Improvements in recall and food choices using a graphical method to deliver information of select nutrients.

    PubMed

    Pratt, Nathan S; Ellison, Brenna D; Benjamin, Aaron S; Nakamura, Manabu T

    2016-01-01

    Consumers have difficulty using nutrition information. We hypothesized that graphically delivering information of select nutrients relative to a target would allow individuals to process information in time-constrained settings more effectively than numerical information. Objectives of the study were to determine the efficacy of the graphical method in (1) improving memory of nutrient information and (2) improving consumer purchasing behavior in a restaurant. Values of fiber and protein per calorie were 2-dimensionally plotted alongside a target box. First, a randomized cued recall experiment was conducted (n=63). Recall accuracy of nutrition information improved by up to 43% when shown graphically instead of numerically. Second, the impact of graphical nutrition signposting on diner choices was tested in a cafeteria. Saturated fat and sodium information was also presented using color coding. Nutrient content of meals (n=362) was compared between 3 signposting phases: graphical, nutrition facts panels (NFP), or no nutrition label. Graphical signposting improved nutrient content of purchases in the intended direction, whereas NFP had no effect compared with the baseline. Calories ordered from total meals, entrées, and sides were significantly less during graphical signposting than no-label and NFP periods. For total meal and entrées, protein per calorie purchased was significantly higher and saturated fat significantly lower during graphical signposting than the other phases. Graphical signposting remained a predictor of calories and protein per calorie purchased in regression modeling. These findings demonstrate that graphically presenting nutrition information makes that information more available for decision making and influences behavior change in a realistic setting. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Effect of Off-Season Flooding on Growth, Photosynthesis, Carbohydrate Partitioning, and Nutrient Uptake in Distylium chinense

    PubMed Central

    Liu, Zebin; Cheng, Ruimei; Xiao, Wenfa; Guo, Quanshui; Wang, Na

    2014-01-01

    Distylium chinense is an evergreen shrub used for the vegetation recovery of floodplain and riparian areas in Three Gorges Reservoir Region. To clarify the morphological and physiological responses and tolerance of Distylium chinense to off-season flooding, a simulation flooding experiment was conducted during autumn and winter. Results indicated that the survival rate of seedlings was 100%, and that plant height and stem diameter were not significantly affected by flooding. Adventitious roots and hypertrophic lenticels were observed in flooded seedlings after 30 days of flooding. Flooding significantly reduced the plant biomass of roots, net photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (Tr), maximum photochemical efficiency (Fv/Fm), photochemical quenching (qP), and electron transport rate (ETR) in leaves, and also affected the allocation and transport of carbohydrate and nutrients. However, D. chinense was able to maintain stable levels of Pn, Fv/Fm, qP, ETR, and nutrient content (N and P) in leaves and to store a certain amount of carbohydrate in roots over prolonged durations of flooding. Based on these results, we conclude that there is a high flooding tolerance in D. chinense, and the high survival rate of D. chinense may be attributable to a combination of morphological and physiological responses to flooding. PMID:25222006

  11. Arbuscular mycorrhizal fungi increased growth, nutrient uptake and tolerance to salinity in olive trees under nursery conditions.

    PubMed

    Porras-Soriano, Andrés; Soriano-Martín, María Luisa; Porras-Piedra, Andrés; Azcón, Rosario

    2009-09-01

    Inoculating olive plantlets with the arbuscular mycorrhizal fungi (AMF) Glomus mosseae, Glomus intraradices or Glomus claroideum increased plant growth and the ability to acquire nitrogen, phosphorus, and potassium from non-saline as well as saline media. AMF-colonized plants also increased in survival rate after transplant. Osmotic stress caused by NaCl supply reduced stem diameter, number of shoots, shoot length and nutrients in olive plants, but AMF colonization alleviated all of these negative effects on growth. G. mosseae was the most efficient fungus in reducing the detrimental effects of salinity; it increased shoot growth by 163% and root growth by 295% in the non-saline medium, and by 239% (shoot) and by 468% (root) under the saline conditions. AMF colonization enhanced salt tolerance in terms of olive growth and nutrient acquisition. Mycorrhizal olive plants showed the lowest biomass reduction under salinity (34%), while growth was reduced by 78% in control plants. This G. mosseae effect seems to be due to increased K acquisition; K content was enhanced under salt conditions by 6.4-fold with G. mosseae, 3.4-fold with G. intraradices, and 3.7-fold with G. claroideum. Potassium, as the most prominent inorganic solute, plays a key role in the osmoregulation processes and the highest salinity tolerance of G. mosseae-colonized olive trees was concomitant with an enhanced K concentration in olive plants.

  12. The role of precision agriculture for improved nutrient management on farms.

    PubMed

    Hedley, Carolyn

    2015-01-01

    Precision agriculture uses proximal and remote sensor surveys to delineate and monitor within-field variations in soil and crop attributes, guiding variable rate control of inputs, so that in-season management can be responsive, e.g. matching strategic nitrogen fertiliser application to site-specific field conditions. It has the potential to improve production and nutrient use efficiency, ensuring that nutrients do not leach from or accumulate in excessive concentrations in parts of the field, which creates environmental problems. The discipline emerged in the 1980s with the advent of affordable geographic positioning systems (GPS), and has further developed with access to an array of affordable soil and crop sensors, improved computer power and software, and equipment with precision application control, e.g. variable rate fertiliser and irrigation systems. Precision agriculture focusses on improving nutrient use efficiency at the appropriate scale requiring (1) appropriate decision support systems (e.g. digital prescription maps), and (2) equipment capable of varying application at these different scales, e.g. the footprint of a one-irrigation sprinkler or a fertiliser top-dressing aircraft. This article reviews the rapid development of this discipline, and uses New Zealand as a case study example, as it is a country where agriculture drives economic growth. Here, the high yield potentials on often young, variable soils provide opportunities for effective financial return from investment in these new technologies.

  13. Effects of In-stream Restorations on Stream Hydrodynamics, Nutrient Uptake, and Ecosystem Metabolism at Fort Benning, GA

    NASA Astrophysics Data System (ADS)

    Roberts, B. J.; Mulholland, P. J.

    2005-05-01

    Spatial variability in military training intensity results in a wide range of upland disturbance intensity at the Fort Benning Military Reservation (near Columbus, GA). We selected stream reaches within 8 catchments with contrasting levels of upland denudation and stream ecosystem disturbance. In October 2003, 4 of these streams (spanning the disturbance gradient) received in-stream restorations in the form of coarse woody debris dams every 10 m for the 100 m study reaches. Stream hydrodynamic properties, NH4+ uptake, and whole-stream metabolism were examined both prior to and after restoration for all 8 streams. In-stream restorations resulted in increases in the relative size of transient storage zones (important for biological processes) and spatial variation in water velocity (enhances habitat variability). These hydrodynamic changes corresponded to increases in both NH4+ uptake rate and velocity as the ability of stream biota to control stream NH4+ concentration increased. By monitoring stream metabolism rates for two years prior to restoration we are able to assess the impact of the restorations on these important integrative processes using a BACI-type analysis (before-after control-treatment analysis) for the first year of post-restoration.

  14. Influence of different acid and alkaline cleaning agents on the effects of irrigation of synthetic dairy factory effluent on soil quality, ryegrass growth and nutrient uptake.

    PubMed

    Liu, Y-Y; Haynes, R J

    2013-01-01

    The aim of this study was to examine the effects of replacement of phosphoric acid with nitric or acetic acid, and replacement of NaOH with KOH, as cleaning agents in dairy factories, on the effects that irrigation of dairy factory effluent (DFE) has on the soil-plant system. A 16-week greenhouse study was carried out in which the effects of addition of synthetic dairy factory effluent containing (a) milk residues alone or milk residues plus (b) H(3)PO(4)/NaOH, (c) H(3)PO(4)/HNO(3)/NaOH or (d) CH(3)COOH/KOH, on soil's chemical, physical and microbial properties and perennial ryegrass growth and nutrient uptake were investigated. The cumulative effect of DFE addition was to increase exchangeable Na, K, Ca, Mg, exchangeable sodium percentage, microbial biomass C and N and basal respiration in the soil. Dry matter yields of ryegrass were increased by additions of DFE other than that containing CH(3)COOH. Plant uptake of P, Ca and Mg was in the same order as their inputs in DFE but for Na; inputs were an order of magnitude greater than plant uptake. Replacement of NaOH by KOH resulted in increased accumulation of exchangeable K. The effects of added NaOH and KOH on promoting breakdown of soil aggregates during wet sieving (and formation of a < 0.25 mm size class) were similar. Replacement of H(2)PO(4) by HNO(3) is a viable but CH(3)COOH appears to have detrimental effects on plant growth. Replacement of NaOH by KOH lowers the likelihood of phytotoxic effects of Na, but K and Na have similar effects on disaggregation.

  15. Biocontrol of Fusarium wilt disease in cucumber with improvement of growth and mineral uptake using some antagonistic formulations.

    PubMed

    Moharam, Moustafa H A; Negim, Osama O

    2012-01-01

    Fusarium wilt disease in Cucumber (Cucumis sativus L.) is widespread, responsible for serious economic losses. Amongst totally 15 isolates of Fusarium spp., obtained from different localities of Sohag governorate, Egypt, only the identified isolates as F. oxysporum were pathogenic on cucumber Denmark Beta-Alpha cv. and caused wilt symptoms. Totally 22 isolates of Trichoderma spp., B. subtilis and Pseudomonas spp., were obtained from rhizosphere of cucumber and some available commercial formulations and then tested for antagonistic activity against F. oxysporum (FO5) in vitro. The highest inhibitory effect on growth of FO5 was observed by isolate Trichodex of T. harzianum (89.29%) followed by Th4 of T. harzianum, Serenade and MBI 600 of B. subtilis, PS3 of Pseudomonas spp., and Treico and Tv2 of T. viride. Pot experiments were performed to investigate the effects of formulated antagonists as seed treatment on Fusarium wilt incidence, growth and mineral uptake of cucumber. Results showed that all tested formulations significantly reduced percent of wilted plants and disease severity, and improved plant growth by increasing length of shoot and root, fresh and dry weight of shoot and root system, and number of leaves and flowers per plant compared with untreated control. They also significantly increased nutrient contents of plant shoot including N, P, K, Ca, Fe, Mn, Cu, and Zn. Magnesium content in shoot slightly not significantly increased. Formulation of Trichodex was the most effective ones followed by Serenade, Th4 and PS3.

  16. Enablers and Barriers to Large-Scale Uptake of Improved Solid Fuel Stoves: A Systematic Review

    PubMed Central

    Puzzolo, Elisa; Stanistreet, Debbi; Pope, Daniel; Bruce, Nigel G.

    2013-01-01

    Background: Globally, 2.8 billion people rely on household solid fuels. Reducing the resulting adverse health, environmental, and development consequences will involve transitioning through a mix of clean fuels and improved solid fuel stoves (IS) of demonstrable effectiveness. To date, achieving uptake of IS has presented significant challenges. Objectives: We performed a systematic review of factors that enable or limit large-scale uptake of IS in low- and middle-income countries. Methods: We conducted systematic searches through multidisciplinary databases, specialist websites, and consulting experts. The review drew on qualitative, quantitative, and case studies and used standardized methods for screening, data extraction, critical appraisal, and synthesis. We summarized our findings as “factors” relating to one of seven domains—fuel and technology characteristics; household and setting characteristics; knowledge and perceptions; finance, tax, and subsidy aspects; market development; regulation, legislation, and standards; programmatic and policy mechanisms—and also recorded issues that impacted equity. Results: We identified 31 factors influencing uptake from 57 studies conducted in Asia, Africa, and Latin America. All domains matter. Although factors such as offering technologies that meet household needs and save fuel, user training and support, effective financing, and facilitative government action appear to be critical, none guarantee success: All factors can be influential, depending on context. The nature of available evidence did not permit further prioritization. Conclusions: Achieving adoption and sustained use of IS at a large scale requires that all factors, spanning household/community and program/societal levels, be assessed and supported by policy. We propose a planning tool that would aid this process and suggest further research to incorporate an evaluation of effectiveness. Citation: Rehfuess EA, Puzzolo E, Stanistreet D, Pope D, Bruce

  17. Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Habib, Shahid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz; Stehr, Jeff

    2011-01-01

    The Gulf of Mexico Modeling Framework is a suite of coupled models linking the deposition and transport of sediment and nutrients to subsequent bio-geo chemical processes and the resulting effect on concentrations of dissolved oxygen in the coastal waters of Louisiana and Texas. Here, we examine the potential benefits of using multiple NASA remote sensing data products within this Modeling Framework for increasing the accuracy of the models and their utility for nutrient control decisions in the Gulf of Mexico. Our approach is divided into three components: evaluation and improvement of (a) the precipitation input data (b) atmospheric constituent concentrations in EPA's air quality/deposition model and (c) the calculation of algal biomass, organic carbon and suspended solids within the water quality/eutrophication models of the framework.

  18. MODEL SIMULATION STUDIES OF SCALE-DEPENDENT GAIN IN STREAM NUTRIENT ASSIMILATIVE CAPACITY RESULTING FROM IMPROVING NUTRIENT RETENTION METRICS

    EPA Science Inventory

    Considering the difficulty in measuring restoration success for nonpoint source pollutants, nutrient assimilative capacity (NAS) offers an attractive systems-based metric. Here NAS was defined using an impulse-response model of nitrate fate and transport. Eleven parameters were e...

  19. MODEL SIMULATION STUDIES OF SCALE-DEPENDENT GAIN IN STREAM NUTRIENT ASSIMILATIVE CAPACITY RESULTING FROM IMPROVING NUTRIENT RETENTION METRICS

    EPA Science Inventory

    Considering the difficulty in measuring restoration success for nonpoint source pollutants, nutrient assimilative capacity (NAS) offers an attractive systems-based metric. Here NAS was defined using an impulse-response model of nitrate fate and transport. Eleven parameters were e...

  20. Korean pine nut oil replacement decreases intestinal lipid uptake while improves hepatic lipid metabolism in mice

    PubMed Central

    Zhu, Shuang; Park, Soyoung; Lim, Yeseo; Shin, Sunhye

    2016-01-01

    BACKGROUND/OBJECTIVES Consumption of pine nut oil (PNO) was shown to reduce weight gain and attenuate hepatic steatosis in mice fed a high-fat diet (HFD). The aim of this study was to examine the effects of PNO on both intestinal and hepatic lipid metabolism in mice fed control or HFD. MATERIALS/METHODS Five-week-old C57BL/6 mice were fed control diets containing 10% energy fat from either Soybean Oil (SBO) or PNO, or HFD containing 15% energy fat from lard and 30% energy fat from SBO or PNO for 12 weeks. Expression of genes related to intestinal fatty acid (FA) uptake and channeling (Cd36, Fatp4, Acsl5, Acbp), intestinal chylomicron synthesis (Mtp, ApoB48, ApoA4), hepatic lipid uptake and channeling (Lrp1, Fatp5, Acsl1, Acbp), hepatic triacylglycerol (TAG) lipolysis and FA oxidation (Atgl, Cpt1a, Acadl, Ehhadh, Acaa1), as well as very low-density lipoprotein (VLDL) assembly (ApoB100) were determined by real-time PCR. RESULTS In intestine, significantly lower Cd36 mRNA expression (P < 0.05) and a tendency of lower ApoA4 mRNA levels (P = 0.07) was observed in PNO-fed mice, indicating that PNO consumption may decrease intestinal FA uptake and chylomicron assembly. PNO consumption tended to result in higher hepatic mRNA levels of Atgl (P = 0.08) and Cpt1a (P = 0.05). Significantly higher hepatic mRNA levels of Acadl and ApoB100 were detected in mice fed PNO diet (P < 0.05). These results suggest that PNO could increase hepatic TAG metabolism; mitochondrial fatty acid oxidation and VLDL assembly. CONCLUSIONS PNO replacement in the diet might function in prevention of excessive lipid uptake by intestine and improve hepatic lipid metabolism in both control diet and HFD fed mice. PMID:27698954

  1. Isolation of rat cardiac sarcoplasmic reticulum with improved Ca2+ uptake and ryanodine binding.

    PubMed

    Feher, J J; Davis, M D

    1991-03-01

    The instability of the oxalate-supported Ca2+ uptake activity of rat cardiac sarcoplasmic reticulum (CSR) in ventricular homogenates most likely accounts for the low specific activity of the rate of oxalate-supported Ca2+ uptake in previously reported fractions of isolated rat CSR. We have found that CSR vesicles with improved Ca2+ transport capabilities can be isolated if 1 M KCl is used to stabilize the CSR activity and to allow the extraction of the CSR from the cellular debris. The average rate of Ca2+ uptake by the isolated rat CSR in the presence of 10 mM oxalate at 37 degrees C was 0.45 mumols/min-mg in the absence of CSR Ca2+ channel blockers and 0.87 mumols/min-mg in the presence of 10 microM ruthenium red. The Ca(2+)-dependent ATPase activity under the conditions of oxlate-supported uptake was 1.25 mumols/min-mg and 0.84 mumols/min-mg in the absence and presence of 10 microM ruthenium red, respectively. The rat CSR vesicles bound 3H-ryanodine with a Kd of 1.45 nM and a Bmax of 3.7 pmol mg. The level of phosphorylated intermediate was 0.30 nmol/mg. The values Bmax, EP and Ca(2+)-ATPase activity are from one-third to one-half of those previously reported for isolated canine CSR vesicles. These results suggest that the isolated rat CSR may be quite similar to dog CSR.

  2. Nutrient Exchange through Hyphae in Intercropping Systems Affects Yields

    ERIC Educational Resources Information Center

    Thun, Tim Von

    2013-01-01

    Arbuscular mycorrhizae fungi (AMF) play a large role in the current understanding of the soil ecosystem. They increase nutrient and water uptake, improve soil structure, and form complex hyphal networks that transfer nutrients between plants within an ecosystem. Factors such as species present, the physiological balance between the plants in the…

  3. Nutrient Exchange through Hyphae in Intercropping Systems Affects Yields

    ERIC Educational Resources Information Center

    Thun, Tim Von

    2013-01-01

    Arbuscular mycorrhizae fungi (AMF) play a large role in the current understanding of the soil ecosystem. They increase nutrient and water uptake, improve soil structure, and form complex hyphal networks that transfer nutrients between plants within an ecosystem. Factors such as species present, the physiological balance between the plants in the…

  4. Effect of calcium carbonate on cadmium and nutrients uptake in tobacco (Nicotiana tabacum L.) planted on contaminated soil.

    PubMed

    Zeng, Wei-Ai; Li, Fan; Zhou, Hang; Qin, Xiao-Li; Zou, Zi-Jin; Tian, Tao; Zeng, Min; Liao, Bo-Han

    2016-01-01

    In the present study, calcium carbonate (CaCO3) was applied to Cd-contaminated soil at rates of 0, 0.5 and 1.0 g kg(-1). The effect of CaCO3 on soil pH, organic matter, available Cd, exchangeable Cd and level of major nutrients in a tobacco field and on accumulation of various elements in tobacco plants was determined. The results showed that CaCO3 application significantly increased the pH level, available P and exchangeable Ca but decreased organic matter, available Cd, exchangeable Cd, available heavy metals (Fe, Mn, Zn and Cu) and available K in soil. Additionally, CaCO3 application substantially reduced Cd accumulation in tobacco roots, stems, upper leaves, middle leaves and lower leaves, with maximum decrease of 22.3%, 32.1%, 24.5%, 22.0% and 18.2%, respectively. There were large increase in total Ca and slight increases in total N and K but decrease to varying degrees in total Fe, Cu and Zn due to CaCO3 application. CaCO3 had little effect on total P and Mn levels in tobacco leaves.

  5. Influence of size and density on filtration rate modeling and nutrient uptake by green mussel (Perna viridis).

    PubMed

    Tantanasarit, Chayarat; Babel, Sandhya; Englande, Andrew J; Meksumpun, Shettapong

    2013-03-15

    This study investigates green mussel filtration rates based on variation of the mussel size and density, and attempts to correlate these with the amount of Chaetoceros calcitrans consumed by kinetic modeling. The filtration rates were found to be more effective in small mussels and with greater volumes of seawater/mussel which represent low mussel densities in the mussel farms. Under field condition, the first order kinetic model is useful for evaluation of mussel filtration rate. However, the composite exponential kinetic model was determined to better describe filtration rates in a close system. Higher ratios of seawater volume L/g DW mussel tissue, resulted in an increasing filtration rate until a maximum plateau was reached at 10.37 L/h/g DW tissue as determined by first order kinetics. Based on the filtration rate, carbon, nitrogen, and phosphorus uptake by green mussels were found to be 2128.72, 265.41, and 66.67 mg/year/indv, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Integration of hollow fiber membranes improves nutrient supply in three-dimensional tissue constructs.

    PubMed

    Bettahalli, N M S; Vicente, J; Moroni, L; Higuera, G A; van Blitterswijk, C A; Wessling, M; Stamatialis, D F

    2011-09-01

    Sufficient nutrient and oxygen transport is a potent modulator of cell proliferation in in vitro tissue-engineered constructs. The lack of oxygen and culture medium can create a potentially lethal environment and limit cellular metabolic activity and growth. Diffusion through scaffold and multi-cellular tissue typically limits transport in vitro, leading to potential hypoxic regions and reduction in the viable tissue thickness. For the in vitro generation of clinically relevant tissue-engineered grafts, current nutrient diffusion limitations should be addressed. Major approaches to overcoming these include culture with bioreactors, scaffolds with artificial microvasculature, oxygen carriers and pre-vascularization of the engineered tissues. This study focuses on the development and utilization of a new perfusion culture system to provide adequate nutrient delivery to cells within large three-dimensional (3D) scaffolds. Perfusion of oxygenated culture medium through porous hollow fiber (HF) integrated within 3D free form fabricated (FFF) scaffolds is proposed. Mouse pre-myoblast (C2C12) cells cultured on scaffolds of poly(ethylene-oxide-terephthalate)-poly(butylene-terephthalate) block copolymer (300PEOT55PBT45) integrated with porous HF membranes of modified poly(ether-sulfone) (mPES, Gambro GmbH) is used as a model system. Various parameters such as fiber transport properties, fiber spacing within a scaffold and medium flow conditions are optimized. The results show that four HF membranes integrated with the scaffold significantly improve the cell density and cell distribution. This study provides a basis for the development of a new HF perfusion culture methodology to overcome the limitations of nutrient diffusion in the culture of large 3D tissue constructs.

  7. Angiotensin 1-7 improves insulin sensitivity by increasing skeletal muscle glucose uptake in vivo.

    PubMed

    Echeverría-Rodríguez, Omar; Del Valle-Mondragón, Leonardo; Hong, Enrique

    2014-01-01

    The renin-angiotensin system (RAS) regulates skeletal muscle insulin sensitivity through different mechanisms. The overactivation of the ACE (angiotensin-converting enzyme)/Ang (angiotensin) II/AT1R (Ang II type 1 receptor) axis has been associated with the development of insulin resistance, whereas the stimulation of the ACE2/Ang 1-7/MasR (Mas receptor) axis improves insulin sensitivity. The in vivo mechanisms by which this axis enhances skeletal muscle insulin sensitivity are scarcely known. In this work, we investigated whether rat soleus muscle expresses the ACE2/Ang 1-7/MasR axis and determined the effect of Ang 1-7 on rat skeletal muscle glucose uptake in vivo. Western blot analysis revealed the expression of ACE2 and MasR, while Ang 1-7 levels were detected in rat soleus muscle by capillary zone electrophoresis. The euglycemic clamp exhibited that Ang 1-7 by itself did not promote glucose transport, but it increased insulin-stimulated glucose disposal in the rat. In a similar manner, captopril (an ACE inhibitor) enhanced insulin-induced glucose uptake and this effect was blocked by the MasR antagonist A-779. Our results show for the first time that rat soleus muscle expresses the ACE2/Ang 1-7/MasR axis of the RAS, and Ang 1-7 improves insulin sensitivity by enhancing insulin-stimulated glucose uptake in rat skeletal muscle in vivo. Thus, endogenous (systemic and/or local) Ang 1-7 could regulate insulin-mediated glucose transport in vivo.

  8. Improved nitrogen nutrition enhances root uptake, root-to-shoot translocation and remobilization of zinc ((65) Zn) in wheat.

    PubMed

    Erenoglu, Emin Bulent; Kutman, Umit Baris; Ceylan, Yasemin; Yildiz, Bahar; Cakmak, Ismail

    2011-01-01

    This study focussed on the effect of increasing nitrogen (N) supply on root uptake and root-to-shoot translocation of zinc (Zn) as well as retranslocation of foliar-applied Zn in durum wheat (Triticum durum). Nutrient solution experiments were conducted to examine the root uptake and root-to-shoot translocation of (65) Zn in seedlings precultured with different N supplies. In additional experiments, the effect of varied N nutrition on retranslocation of foliar-applied (65) Zn was tested at both the vegetative and generative stages. When N supply was increased, the (65) Zn uptake by roots was enhanced by up to threefold and the (65) Zn translocation from roots to shoots increased by up to eightfold, while plant growth was affected to a much smaller degree. Retranslocation of (65) Zn from old into young leaves and from flag leaves to grains also showed marked positive responses to increasing N supply. The results demonstrate that the N-nutritional status of wheat affects major steps in the route of Zn from the growth medium to the grain, including its uptake, xylem transport and remobilization via phloem. Thus, N is a critical player in the uptake and accumulation of Zn in plants, which deserves special attention in biofortification of food crops with Zn. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

  9. Nitrogen fertilizer enhances growth and nutrient uptake of Medicago sativa inoculated with Glomus tortuosum grown in Cd-contaminated acidic soil.

    PubMed

    Liu, Mohan; Sun, Jian; Li, Yang; Xiao, Yan

    2017-01-01

    This study aimed to explore whether nitrogen availability could influence mycorrhizal function and their associations with host plants in Cd-contaminated acidic soils or not. A greenhouse pot experiment was conducted to assess the effects of mycorrhizal inoculation (non-mycorrhizal inoculation (NM), Glomus aggregatum (Ga), G. tortuosum (Gt) and G. versiforme (Gv)) and inorganic N amendment on the growth, nutrient and Cd uptake of Medicago sativa grown in Cd-contaminated acidic soils (10 mg Cd kg(-1) soil). AMF inoculations significantly increased the shoot and total biomass and decreased the shoot Cd concentration in comparison to plants uninoculated. N addition increased markedly concentration and content of N and decreased those of P in plants at all inoculation treatments. Shoot K, Na and Mg concentration in plants inoculated with Ga and Gv were decreased by N addition, whereas shoot K, Na, Ca and Mg concentration in plants inoculated with Gt were not negatively affected. It was observed that N addition only increased mycorrhizal colonization, shoot biomass, shoot K, Ca and Mg content of plants inoculated with Gt. Irrespective of N addition, plants with Gt inoculation got the maximum shoot and root P concentration and content, as well as P/Cd concentration molar ratio among all inoculation treatment. Neither AMF nor N fertilizer contributed to the decrease of soil exchangeable Cd and increase of soil pH. These results suggested that N fertilizer only elevated plant performance of alfalfa with Gt inoculation grown in acidic soil, by diluting Cd concentration and alleviating of nutrient deficiency, especially P.

  10. Maximizing root/rhizosphere efficiency to improve crop productivity and nutrient use efficiency in intensive agriculture of China.

    PubMed

    Shen, Jianbo; Li, Chunjian; Mi, Guohua; Li, Long; Yuan, Lixing; Jiang, Rongfeng; Zhang, Fusuo

    2013-03-01

    Root and rhizosphere research has been conducted for many decades, but the underlying strategy of root/rhizosphere processes and management in intensive cropping systems remain largely to be determined. Improved grain production to meet the food demand of an increasing population has been highly dependent on chemical fertilizer input based on the traditionally assumed notion of 'high input, high output', which results in overuse of fertilizers but ignores the biological potential of roots or rhizosphere for efficient mobilization and acquisition of soil nutrients. Root exploration in soil nutrient resources and root-induced rhizosphere processes plays an important role in controlling nutrient transformation, efficient nutrient acquisition and use, and thus crop productivity. The efficiency of root/rhizosphere in terms of improved nutrient mobilization, acquisition, and use can be fully exploited by: (1) manipulating root growth (i.e. root development and size, root system architecture, and distribution); (2) regulating rhizosphere processes (i.e. rhizosphere acidification, organic anion and acid phosphatase exudation, localized application of nutrients, rhizosphere interactions, and use of efficient crop genotypes); and (3) optimizing root zone management to synchronize root growth and soil nutrient supply with demand of nutrients in cropping systems. Experiments have shown that root/rhizosphere management is an effective approach to increase both nutrient use efficiency and crop productivity for sustainable crop production. The objectives of this paper are to summarize the principles of root/rhizosphere management and provide an overview of some successful case studies on how to exploit the biological potential of root system and rhizosphere processes to improve crop productivity and nutrient use efficiency.

  11. Room for improvement? Leadership, innovation culture and uptake of quality improvement methods in general practice.

    PubMed

    Apekey, Tanefa A; McSorley, Gerry; Tilling, Michelle; Siriwardena, A Niroshan

    2011-04-01

    Leadership and innovation are currently seen as essential elements for the development and maintenance of high-quality care. Little is known about the relationship between leadership and culture of innovation and the extent to which quality improvement methods are used in general practice. This study aimed to assess the relationship between leadership behaviour, culture of innovation and adoption of quality improvement methods in general practice. Self-administered postal questionnaires were sent to general practitioner quality improvement leads in one county in the UK between June and December 2007. The questionnaire consisted of background information, a 12-item scale to assess leadership behaviour, a seven-dimension self-rating scale for culture of innovation and questions on current use of quality improvement tools and techniques. Sixty-three completed questionnaires (62%) were returned. Leadership behaviours were not commonly reported. Most practices reported a positive culture of innovation, featuring relationship most strongly, followed by targets and information but rated lower on other dimensions of rewards, risk and resources. There was a significant positive correlation between leadership behaviour and the culture of innovation (r = 0.57; P < 0.001). Apart from clinical audit and significant event analysis, quality improvement methods were not adopted by most participating practices. Leadership behaviours were infrequently reported and this was associated with a limited culture of innovation in participating general practices. There was little use of quality improvement methods beyond clinical and significant event audit. Practices need support to enhance leadership skills, encourage innovation and develop quality improvement skills if improvements in health care are to accelerate. © 2010 Blackwell Publishing Ltd.

  12. Content and uptake of minerals in the yolk of broiler embryos during incubation and effect of nutrient enrichment.

    PubMed

    Yair, R; Uni, Z

    2011-07-01

    Although embryo and chicken growth and development rely on mineral nutrition, information on mineral levels in the egg compartments during incubation is limited. Accordingly, we examined P, Ca, Fe, Zn, Cu, and Mn levels in the yolk of breeder eggs during incubation and the effect of embryonic mineral (with specific nutrients) enrichment on yolk mineral levels and consumption. First, fertile eggs were examined on day of setting (DOS), embryonic day (E) 11, E13, E15, E17, E19, E20, and day of hatch (DOH) for the mineral content in the yolk (and albumen on DOS) by inductively coupled plasma atomic emission spectroscopy. Results showed that on DOS, the yolk is the major origin for Mn, P, Fe, Ca, Cu, and Zn. Interestingly, P, Fe, Zn, Cu, and Mn were mostly consumed from the yolk until E17, after which their consumption was very low. Consumption of P was constant until E17 and then decreased until E20. Consumption of Fe, Zn, Cu, and Mn was medium to mild until E11, increased between E11 and E17, and minimal between E17 and DOH. Enrichment treatment, where fertile eggs were divided into 2 groups [nonenriched (control) and enriched (with minerals, vitamins, and carbohydrates on E17 using the in ovo feeding method)] showed that the enriched group had higher Fe, Zn, Cu, and Mn levels than the nonenriched group and exhibited higher consumption of Fe, Zn, and Mn between E20 and DOH. Analysis of the shell mineral composition along incubation showed that the shell released low amounts of P, Fe, and Mn in comparison with the yolk mineral content. Therefore, we concluded that the shell is a minor source of these minerals. Studying the mineral resources and consumption of embryos can lead to a better understanding of the mineral limitations of embryos during incubation. Additionally, because minerals are important for the development of the embryo, the higher mineral levels and consumption observed in the enriched group may affect the development of critical organs, such as the

  13. Whole Genome Sequencing Reveals Potential New Targets for Improving Nitrogen Uptake and Utilization in Sorghum bicolor

    PubMed Central

    Massel, Karen; Campbell, Bradley C.; Mace, Emma S.; Tai, Shuaishuai; Tao, Yongfu; Worland, Belinda G.; Jordan, David R.; Botella, Jose R.; Godwin, Ian D.

    2016-01-01

    Nitrogen (N) fertilizers are a major agricultural input where more than 100 million tons are supplied annually. Cereals are particularly inefficient at soil N uptake, where the unrecovered nitrogen causes serious environmental damage. Sorghum bicolor (sorghum) is an important cereal crop, particularly in resource-poor semi-arid regions, and is known to have a high NUE in comparison to other major cereals under limited N conditions. This study provides the first assessment of genetic diversity and signatures of selection across 230 fully sequenced genes putatively involved in the uptake and utilization of N from a diverse panel of sorghum lines. This comprehensive analysis reveals an overall reduction in diversity as a result of domestication and a total of 128 genes displaying signatures of purifying selection, thereby revealing possible gene targets to improve NUE in sorghum and cereals alike. A number of key genes appear to have been involved in selective sweeps, reducing their sequence diversity. The ammonium transporter (AMT) genes generally had low allelic diversity, whereas a substantial number of nitrate/peptide transporter 1 (NRT1/PTR) genes had higher nucleotide diversity in domesticated germplasm. Interestingly, members of the distinct race Guinea margaritiferum contained a number of unique alleles, and along with the wild sorghum species, represent a rich resource of new variation for plant improvement of NUE in sorghum. PMID:27826302

  14. [Effect of microbial nutrient concentration on improvement of municipal sewage sludge dewaterability through bioleaching].

    PubMed

    Song, Yong-wei; Liu, Fen-wu; Zhou, Li-xiang

    2012-08-01

    In this study, shaking flask batch experiments and practical engineering application tests were performed to investigate the effect of microbial nutrient concentration on the dewaterability of municipal sewage sludge with 2%, 3%, 4% and 5% solid contents via bioleaching. Meanwhile, the changes of pH value and the utilization efficiency of microbial nutrients during bioleaching were analyzed in this study. The results showed that the pH value decreased gradually at the beginning and then maintained a stable state in the treatments with different solid contents, and the nutrients were completely used up by the microorganisms after 2 days of bioleaching. It was found that the SRF of 2%, 3%, 4%, 5% sludges decreased quickly and then rose gradually with the extension of bioleaching time. In addition, the higher solid content the greater the increase. It was determined that the optimum microbial nutrient dosage for sludge with solid content of 2%, 3%, 4% and 5% were 3.0 g x L(-1), 4.5 g x L(-1), 8.3 g x L(-1) and 12.8 g x L(-1) respectively. At this point, the lowest SRF of sludge with each solid content were 0.61 x 10(12) m x kg(-1), 1.22 x 10(12) m x kg(-1), 3.09 x 10(12) m x kg(-1) and 4.83 x 10(12) m x kg(-1), respectively. Through the engineering application, it was showed that diluting the solid content of sewage sludge from 5% to 3% before bioleaching was feasible. It could not only improve the dewaterability of bioleached sewage sludge (the SRF declined from 3.29 x 10(12) m x kg(-1) to 1.10 x 10(12) m x kg(-1)), but also shorten the sludge nutrient time (shortened from 4 days to 2.35 days) and reduce the operation costs. Therefore, the results of this study have important significance for the engineering application of bioleaching of municipal sewage sludge with high solid content.

  15. Impact of defoliation intensities on plant biomass, nutrient uptake and arbuscular mycorrhizal symbiosis in Lotus tenuis growing in a saline-sodic soil.

    PubMed

    García, I; Mendoza, R

    2012-11-01

    The impact of different defoliation intensities on the ability of Lotus tenuis plants to regrowth, mobilise nutrients and to associate with native AM fungi and Rhizobium in a saline-sodic soil was investigated. After 70 days, plants were subjected to 0, 25, 50, 75 and 100% defoliation and shoot regrowth was assessed at the end of subsequent 35 days. Compared to non-defoliated plants, low or moderate defoliation up to 75% did not affect shoot regrowth. However, 100% treatment affected shoot regrowth and the clipped plants were not able to compensate the growth attained by non-defoliated plants. Root growth was more affected by defoliation than shoot growth. P and N concentrations in shoots and roots increased with increasing defoliation while Na(+) concentration in shoots of non-defoliated and moderately defoliated plants was similar. Non-defoliated and moderately defoliated plants prevented increases of Na(+) concentration in shoots through both reducing Na(+) uptake and Na(+) transport to shoots by accumulating Na(+) in roots. At high defoliation, the salinity tolerance mechanism is altered and Na(+) concentration in shoots was higher than in roots. Reduction in the photosynthetic capacity induced by defoliation neither changed the root length colonised by AM fungi nor arbuscular colonisation but decreased the vesicular colonisation. Spore density did not change, but hyphal density and Rhizobium nodules increased with defoliation. The strategy of the AM symbiont consists in investing most of the C resources to preferentially retain arbuscular colonisation as well as inoculum density in the soil.

  16. Improving phosphorus uptake and wheat productivity by phosphoric acid application in alkaline calcareous soils.

    PubMed

    Akhtar, Muhammad; Yaqub, Muhammad; Naeem, Asif; Ashraf, Muhammad; Hernandez, Vicente Espinosa

    2016-08-01

    Low phosphorus (P) efficiency from existing granular fertilisers necessitates searching for efficient alternatives to improve wheat productivity in calcareous soil. Multi-location trials have shown that phosphoric acid (PA) produced 16% higher wheat grain over commercial P fertilisers, i.e. diammonium phosphate (DAP) and triple superphosphate (TSP). Methods of P application significantly influenced grain yield and the efficiency of methods was observed in the order: PA placement below seed > PA, DAP or TSP fertigation > DAP or TSP broadcast. The sub-surface application of PA produced highest grain yields (mean of all rates), i.e. 4669, 4158 and 3910 kg ha(-1) in Bagh, Bhalwal and Shahpur soil series, respectively. Phosphoric acid at 66 kg P2 O5 ha(-1) was found more effective in increasing gain yield over that of control. Trend in grain P uptake was found similar to that observed for grain yield. Maximum P uptake by grain was recorded at the highest P rate and the lowest at zero P. The significant increase in P uptake with P rates was generally related to the increase in yield rather than its concentration in grain. Phosphorus agronomic efficiency (PAE) and phosphorus recovery efficiency (PRE) were found higher at lower P rate (44 kg P2 O5 ha(-1) ) and decreased with P application. However, PA applied by the either method resulted in higher PAE and PRE compared to DAP and TSP. Phosphoric acid is suggested as an efficient alternative to commercial granular P fertilisers for wheat production in alkaline calcareous soils. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  17. Improving prediction of metal uptake by Chinese cabbage (Brassica pekinensis L.) based on a soil-plant stepwise analysis.

    PubMed

    Zhang, Sha; Song, Jing; Gao, Hui; Zhang, Qiang; Lv, Ming-Chao; Wang, Shuang; Liu, Gan; Pan, Yun-Yu; Christie, Peter; Sun, Wenjie

    2016-11-01

    It is crucial to develop predictive soil-plant transfer (SPT) models to derive the threshold values of toxic metals in contaminated arable soils. The present study was designed to examine the heavy metal uptake pattern and to improve the prediction of metal uptake by Chinese cabbage grown in agricultural soils with multiple contamination by Cd, Cu, Ni, Pb, and Zn. Pot experiments were performed with 25 historically contaminated soils to determine metal accumulation in different parts of Chinese cabbage. Different soil bioavailable metal fractions were determined using different extractants (0.43M HNO3, 0.01M CaCl2, 0.005M DTPA, and 0.01M LWMOAs), soil moisture samplers, and diffusive gradients in thin films (DGT), and the fractions were compared with shoot metal uptake using both direct and stepwise multiple regression analysis. The stepwise approach significantly improved the prediction of metal uptake by cabbage over the direct approach. Strongly pH dependent or nonlinear relationships were found for the adsorption of root surfaces and in root-shoot uptake processes. Metals were linearly translocated from the root surface to the root. Therefore, the nonlinearity of uptake pattern is an important explanation for the inadequacy of the direct approach in some cases. The stepwise approach offers an alternative and robust method to study the pattern of metal uptake by Chinese cabbage (Brassica pekinensis L.).

  18. Iron-Responsive Olfactory Uptake of Manganese Improves Motor Function Deficits Associated with Iron Deficiency

    PubMed Central

    Kim, Jonghan; Li, Yuan; Buckett, Peter D.; Böhlke, Mark; Thompson, Khristy J.; Takahashi, Masaya; Maher, Timothy J.; Wessling-Resnick, Marianne

    2012-01-01

    Iron-responsive manganese uptake is increased in iron-deficient rats, suggesting that toxicity related to manganese exposure could be modified by iron status. To explore possible interactions, the distribution of intranasally-instilled manganese in control and iron-deficient rat brain was characterized by quantitative image analysis using T1-weighted magnetic resonance imaging (MRI). Manganese accumulation in the brain of iron-deficient rats was doubled after intranasal administration of MnCl2 for 1- or 3-week. Enhanced manganese level was observed in specific brain regions of iron-deficient rats, including the striatum, hippocampus, and prefrontal cortex. Iron-deficient rats spent reduced time on a standard accelerating rotarod bar before falling and with lower peak speed compared to controls; unexpectedly, these measures of motor function significantly improved in iron-deficient rats intranasally-instilled with MnCl2. Although tissue dopamine concentrations were similar in the striatum, dopamine transporter (DAT) and dopamine receptor D1 (D1R) levels were reduced and dopamine receptor D2 (D2R) levels were increased in manganese-instilled rats, suggesting that manganese-induced changes in post-synaptic dopaminergic signaling contribute to the compensatory effect. Enhanced olfactory manganese uptake during iron deficiency appears to be a programmed “rescue response” with beneficial influence on motor impairment due to low iron status. PMID:22479410

  19. Phenolic esters of O-desmethylvenlafaxine with improved oral bioavailability and brain uptake.

    PubMed

    Zhang, Yang; Yang, Yan; Zhao, Sen; Yang, Zhichao; Yang, Hong; Fawcett, J Paul; Li, Youxin; Gu, Jingkai; Sun, Tiemin

    2013-12-04

    O-Desmethylvenlafaxine (desvenlafaxine, ODV) is a recently approved antidepressant which in some clinical studies failed to meet a satisfactory end-point. The aim of this study was to prepare a series of phenolic esters of ODV and evaluate their potential as ODV prodrugs with improved brain uptake. Fifteen phenolic esters (compounds 1a-o) were synthesized and their pharmacokinetic profiles evaluated in rat. The four compounds producing the highest relative bioavailability of ODV in rat (compounds 1c, 1e, 1n, 1o) were then studied to evaluate their brain uptake. Of these four compounds, compound 1n (the piperonylic acid ester of ODV) demonstrated the highest C(max) of ODV both in the rat hypothalamus and total brain. Finally the pharmacokinetics of 1n were evaluated in beagle dog where the increase in relative bioavailability of ODV was found to be as great as in rat. This high relative bioavailability of ODV coupled with its good brain penetration make 1n the most promising candidate for development as an ODV prodrug.

  20. Uptake and effectiveness of a community pharmacy intervention programme to improve asthma management.

    PubMed

    Bereznicki, B J; Peterson, G; Jackson, S; Walters, E H; George, J; Stewart, K; March, G J

    2013-06-01

    Pharmacists frequently see patients with asthma in the community who have suboptimal management. This study aimed to compare the uptake and effectiveness of pharmacist-initiated mailed and face-to-face interventions for patients whose asthma may not be well managed. Seventy-one community pharmacies in South Australia, Tasmania and Victoria (Australia) installed a software application that data-mined dispensing records, generating a list of patients who had received six or more asthma reliever inhalers in the preceding 12 months. The pharmacists were randomized, by pharmacy, to perform either a mailed or face-to-face intervention, whereby these patients received educational material and a referral to their general practitioner (GP) for an asthma management review. Matching patients from each pharmacy were also randomly assigned to a control group for 'usual care'. A total of 1483 patients were identified and grouped as follows: 510 (34·4%) mailed intervention, 480 (32·4%) face-to-face intervention and 493 (33·2%) controls. Significantly fewer face-to-face interventions were offered than mailed interventions (66·6% vs. 89·4%, respectively; χ(2) = 64·2, P < 0·0001). There were significant improvements in the preventer-to-reliever ratio after the intervention period (P < 0·0001) in each group. In a per-protocol analysis, the magnitude of improvement in the face-to-face intervention group was greater than in the mailed intervention group. The reverse was true in an intention-to-treat analysis. The improvement in the P : R ratios was mainly due to significant decreases in reliever usage. Community pharmacy dispensing records can effectively identify patients with suboptimal asthma management, who can then be referred to their GP for review. Time constraints in busy pharmacies may limit the uptake and effectiveness of face-to-face interventions in the 'real world' setting, making mailed interventions an attractive option. © 2013 Blackwell Publishing Ltd.

  1. Ready-to-eat cereals improve nutrient, milk and fruit intake at breakfast in European adolescents.

    PubMed

    Michels, Nathalie; De Henauw, Stefaan; Beghin, Laurent; Cuenca-García, Magdalena; Gonzalez-Gross, Marcela; Hallstrom, Lena; Kafatos, Anthony; Kersting, Mathilde; Manios, Yannis; Marcos, Ascensión; Molnar, Denes; Roccaldo, Romana; Santaliestra-Pasías, Alba M; Sjostrom, Michael; Reye, Béatrice; Thielecke, Frank; Widhalm, Kurt; Claessens, Mandy

    2016-03-01

    Breakfast consumption has been recommended as part of a healthy diet. Recently, ready-to-eat cereals (RTEC) became more popular as a breakfast item. Our aim was to analyse the dietary characteristics of an RTEC breakfast in European adolescents and to compare them with other breakfast options. From the European multi-centre HELENA study, two 24-h dietary recalls of 3137 adolescents were available. Food items (RTEC or bread, milk/yoghurt, fruit) and macro- and micronutrient intakes at breakfast were calculated. Cross-sectional regression analyses were adjusted for gender, age, socio-economic status and city. Compared to bread breakfasts (39 %) and all other breakfasts (41.5 %), RTEC breakfast (19.5 %) was associated with improved nutrient intake (less fat and less sucrose; more fibre, protein and some micronutrients like vitamin B, calcium, magnesium and phosphorus) at the breakfast occasion. Exceptions were more simple sugars in RTEC breakfast consumers: more lactose and galactose due to increased milk consumption, but also higher glucose and fructose than bread consumers. RTEC consumers had a significantly higher frequency (92.5 vs. 50.4 and 60.2 %) and quantity of milk/yoghurt intake and a slightly higher frequency of fruit intake (13.4 vs. 10.9 and 8.0 %) at breakfast. Among European adolescents, RTEC consumers showed a more favourable nutrient intake than consumers of bread or other breakfasts, except for simple sugars. Therefore, RTEC may be regarded as a good breakfast option as part of a varied and balanced diet. Nevertheless, more research is warranted concerning the role of different RTEC types in nutrient intake, especially for simple sugars.

  2. Mitochondrial Hormesis links nutrient restriction to improved metabolism in fat cell.

    PubMed

    Lettieri Barbato, Daniele; Tatulli, Giuseppe; Aquilano, Katia; Ciriolo, Maria R

    2015-10-01

    Fasting promotes longevity by reprogramming metabolic and stress resistance pathways. However, although the impact on adipose tissue physiology through hormonal inputs is well established, the direct role of fasting on adipose cells is poorly understood. Herein we show that white and beige adipocytes, as well as mouse epididymal and subcutaneous adipose depots, respond to nutrient scarcity by acquiring a brown-like phenotype. Indeed, they improve oxidative metabolism through modulating the expression of mitochondrial- and nuclear-encoded oxidative phosphorylation genes as well as mitochondrial stress defensive proteins (UCP1, SOD2). Such adaptation is placed in a canonical mitohormetic response that proceeds via mitochondrial reactive oxygen species ((mt)ROS) production and redistribution of FoxO1 transcription factor into nucleus. Nuclear FoxO1 ((n)FoxO1) mediates retrograde communication by inducing the expression of mitochondrial oxidative and stress defensive genes. Collectively, our findings describe an unusual white/beige fat cell response to nutrient availability highlighting another health-promoting mechanism of fasting.

  3. Inoculation with arbuscular mycorrhizae does not improve 137Cs uptake in crops grown in the Chernobyl region.

    PubMed

    Vinichuk, M; Mårtensson, A; Rosén, K

    2013-12-01

    Methods for cleaning up radioactive contaminated soils are urgently needed. In this study we investigated whether the use of arbuscular mycorrhizal (AM) fungi can improve (137)Cs uptake by crops. Barley, cucumber, perennial ryegrass, and sunflower were inoculated with AM fungi and grown in low-level radionuclide contaminated soils in a field experiment 70 km southwest of Chernobyl, Ukraine, during two successive years (2009-2010). Roots of barley, cucumber and sunflower plants were slightly or moderately infected with AM fungus and root infection frequency was negatively or non-correlated with (137)Cs uptake by plants. Roots of ryegrass were moderately infected with AM fungus and infection frequency was moderately correlated with (137)Cs uptake by ryegrass. The application of AM fungi to soil in situ did not enhance radionuclide plant uptake or biomass. The responsiveness of host plants and AM fungus combination to (137)Cs uptake varied depending on the soil, although mycorrhization of soil in the field was conditional and did not facilitate the uptake of radiocesium. The total amount of (137)Cs uptake by plants growing on inoculated soil was equal to amounts in plant cultivated on non-inoculated soil. Thus, the use of AM fungi in situ for bioremediation of soil contaminated with a low concentration of (137)Cs could not be recommended.

  4. Nutrient Database improvement project: Separable components and proximate composition of retail cuts from the beef chuck

    USDA-ARS?s Scientific Manuscript database

    This study was designed to provide updated information on the separable components, cooking yields, and nutrient values of retail cuts from the beef chuck. Ultimately, these data will be used in the United States Department of Agriculture (USDA) Nutrient Data Laboratory’s (NDL) National Nutrient Da...

  5. Improving the Quality of Postabortion Care Services in Togo Increased Uptake of Contraception.

    PubMed

    Mugore, Stembile; Kassouta, Ntapi Tchiguiri K; Sebikali, Boniface; Lundstrom, Laurel; Saad, Abdulmumin

    2016-09-28

    High-quality postabortion care (PAC) services that include family planning counseling and a full range of contraceptives at point of treatment for abortion complications have great potential to break the cycle of repeat unintended pregnancies and demand for abortions. We describe the first application of a systematic approach to quality improvement of PAC services in a West African country. This approach-IntraHealth International's Optimizing Performance and Quality (OPQ) approach-was applied at 5 health care facilities in Togo starting in November 2014. A baseline assessment identified the following needs: reorganizing services to ensure that contraceptives are provided at point of treatment for abortion complications, before PAC clients are discharged; improving provider competencies in family planning services, including in providing long-acting reversible contraceptive implants and intrauterine devices; ensuring that contraceptive methods are available to all PAC clients free of charge; standardizing PAC registers and enhancing data collection and reporting systems; enhancing internal supervision systems at facilities and teamwork among PAC providers; and engaging PAC providers in community talks. Solutions devised and applied at the facilities during OPQ resulted in significant increases in contraceptive counseling and uptake among PAC clients: During the 5-month baseline period, 31% of PAC clients were counseled, while during the 13-month intervention period, 91% were counseled. Of all PAC clients counseled during the baseline period, 37% accepted a contraceptive, compared with 60% of those counseled during the intervention period. Oral contraceptive pills remained the most popular method during both periods, yet uptake of implants increased significantly during the intervention period-from 4% to 27% of those accepting contraceptives. This result demonstrates that the solutions applied maintained method choice while expanding access to underused long

  6. Improving HIV test uptake and case finding with assisted partner notification services.

    PubMed

    Dalal, Shona; Johnson, Cheryl; Fonner, Virginia; Kennedy, Caitlin E; Siegfried, Nandi; Figueroa, Carmen; Baggaley, Rachel

    2017-08-24

    Despite the enormous expansion of HIV testing services (HTS), an estimated 40% of people with HIV infection remain undiagnosed. To enhance the efficiency of HTS, new approaches are needed. The WHO conducted a systematic review on the effectiveness of assisted partner notification in improving HIV test uptake and diagnosis, and the occurrence of adverse events, to inform the development of normative guidelines. We systematically searched five electronic databases through June 2016. We also contacted experts in the field and study authors for additional information where needed. Eligible studies compared assisted HIV partner notification services to passive or no notification. Where multiple studies reported comparable outcomes, meta-analysis was conducted using a random-effects model to produce relative risks (RRs) or risk ratios and 95% confidence intervals (CIs). Of 1742 citations identified, four randomized controlled trials and six observational studies totalling 5150 index patients from eight countries were included. Meta-analysis of three individually randomized trials showed that assisted partner notification services resulted in a 1.5-fold increase in HTS uptake among partners compared with passive referral (RR = 1.46; 95% CI: 1.22-1.75; I = 0%). The proportion of HIV-positive partners was 1.5 times higher with assisted partner notification than with passive referral (RR = 1.47; 95% CI: 1.12-1.92; I = 0%). Few instances of violence or harm occurred. Assisted partner notification improved partner testing and diagnosis of HIV-positive partners, with few reports of harm. WHO strongly recommends voluntary assisted HIV partner notification services to be offered as part of a comprehensive package of testing and care.

  7. Improving HIV test uptake and case finding with assisted partner notification services

    PubMed Central

    Dalal, Shona; Johnson, Cheryl; Fonner, Virginia; Kennedy, Caitlin E.; Siegfried, Nandi; Figueroa, Carmen; Baggaley, Rachel

    2017-01-01

    Objective: Despite the enormous expansion of HIV testing services (HTS), an estimated 40% of people with HIV infection remain undiagnosed. To enhance the efficiency of HTS, new approaches are needed. The WHO conducted a systematic review on the effectiveness of assisted partner notification in improving HIV test uptake and diagnosis, and the occurrence of adverse events, to inform the development of normative guidelines. Methods: We systematically searched five electronic databases through June 2016. We also contacted experts in the field and study authors for additional information where needed. Eligible studies compared assisted HIV partner notification services to passive or no notification. Where multiple studies reported comparable outcomes, meta-analysis was conducted using a random-effects model to produce relative risks (RRs) or risk ratios and 95% confidence intervals (CIs). Results: Of 1742 citations identified, four randomized controlled trials and six observational studies totalling 5150 index patients from eight countries were included. Meta-analysis of three individually randomized trials showed that assisted partner notification services resulted in a 1.5-fold increase in HTS uptake among partners compared with passive referral (RR = 1.46; 95% CI: 1.22–1.75; I2 = 0%). The proportion of HIV-positive partners was 1.5 times higher with assisted partner notification than with passive referral (RR = 1.47; 95% CI: 1.12–1.92; I2 = 0%). Few instances of violence or harm occurred. Conclusion: Assisted partner notification improved partner testing and diagnosis of HIV-positive partners, with few reports of harm. WHO strongly recommends voluntary assisted HIV partner notification services to be offered as part of a comprehensive package of testing and care. PMID:28590326

  8. Elevated CO2 enhances photosynthetic efficiency, ion uptake and antioxidant activity of Gynura bicolor DC. grown in a porous-tube nutrient delivery system under simulated microgravity.

    PubMed

    Wang, M; Liu, H; Dong, C; Fu, Y; Liu, H

    2016-05-01

    It is well known that plants can grow under space conditions, however, perturbations of many biological phenomena have been highlighted due to the effect of altered gravity and its possible interaction with other factors (e.g., CO2 , ion radiation, etc. Our aim was to test whether elevated CO2 could provide 'protection' to Gynura bicolor against the damaging effects of simulated microgravity (SM) on photosynthesis, ion uptake and antioxidant activity. As compared to G. bicolor grown in ambient CO2 with no SM (ACO2 ), growth and yield of the plants increased under elevated ambient CO2 with no SM (ECO2 ) and decreased under ACO2 +SM, whereas there was no significant effect on ECO2 +SM. Reductions in the content of Chl a, carotenoids and Chl a+b were 17.9%, 20.7% and 17.9% under ACO2 +SM, respectively, but under ECO2 there was a significant effect on all photosynthetic pigments except Chl b, compared to ACO2 . Photosynthesis was improved under ECO2 with SM and such an improvement was associated with improved water use efficiency and instantaneous carboxylation efficiency. Furthermore, SM caused a reduction in ion absorption rate, except for Ca(2+) , while ECO2 increased the uptake rate. Finally, the activity of SOD, POD and the content of MDA and H2 O2 were enhanced under SM treatments and were highest in ACO2 +SM. In contrast, T-AOC activity and GSH content significantly declined in ACO2 +SM compared to other treatments. These results suggest that ACO2 is not sufficient to counteract SM impact, but the increase is usually caused by improvement in CO2 nutrition in ECO2 +SM in comparison with ACO2 +SM. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. [Effects of two controlled-release fertilizers with different proportions of N, P and K on the nutrient uptake and growth of Chrysanthemum morifolium Ramat].

    PubMed

    Zhu, Li-Xiang; Wang, Jian-Hua; Sun, Yin-Shi; Li, Yu-Peng; Sun, Li-Wen; Zhang, Chun-Ling

    2009-07-01

    A pot experiment was conducted to study the effects of two controlled-release fertilizers CRFA (4% resin-coated, N: P2O5: K2O = 14: 14: 14) and CRFB (4% resin-coated, N: P2O5: K2O = 20: 8:10) on the nutrient uptake and growth of Chrysanthemum morifolium, with common compound fertilizer CCF (N: P2O5: K2O = 15: 15: 15) as the control. Six treatments were installed, i. e., CCF1 (CCF, 6 g N x pot(-1)), CCF2 (CCF, 3 g N x pot(-1)), CRFA1 (CRFA, 6 g x pot(-1)), CRFA2 (CRFA, 3 g x pot(-1)), CRFB1 (CRFB, 6 g x pot(-1)), and CRFB (CRFB, 3 g x pot(-1)). On the 30th day of applying common compound fertilizer CCF1 and CCF2, soil available N, P and K contents were 163.29 and 145.26 mg x kg(-1), 180.39 and 163.13 mg x kg(-1), and 300.08 and 213.15 mg x kg(-1), respectively, and decreased rapidly since then. In treatments CRFA1, CRFB1, CRFA2, and CRFB, soil available N content increased slowly, and reached the peak on the 60th day after fertilizing, being 129.51, 138.65, 118.36, and 126.31 mg x kg(-1), respectively. Soil available P content had the same variation trend. Its maximum concentration was 169.54 and 133.46 mg x kg(-1) in treatments CRFA1 and CRFA2 on the 30th day after fertilizing, and 137.13 and 84.68 mg x kg(-1) in treatments CRFB1 and CRFB2 on the 60th day after fertilizing, and decreased slowly then. The agronomic traits such as leaf area, leaf area index, branch number, flowering rate, flower number, and flower diameter, etc., in treatments CRFA and CRFB were obviously better than those of the control, and CRFB was better than CRFA, suggesting that CRFB more matched the nutrient demand of C. morifolium. Under the conditions of present experiment, applying CRFB2 obtained the highest yield.

  10. Application of electrochemical processes to membrane bioreactors for improving nutrient removal and fouling control.

    PubMed

    Borea, Laura; Naddeo, Vincenzo; Belgiorno, Vincenzo

    2017-01-01

    Membrane bioreactor (MBR) technology is becoming increasingly popular as wastewater treatment due to the unique advantages it offers. However, membrane fouling is being given a great deal of attention so as to improve the performance of this type of technology. Recent studies have proven that the application of electrochemical processes to MBR represents a promising technological approach for membrane fouling control. In this work, two intermittent voltage gradients of 1 and 3 V/cm were applied between two cylindrical perforated electrodes, immersed around a membrane module, at laboratory scale with the aim of investigating the treatment performance and membrane fouling formation. For comparison purposes, the reactor also operated as a conventional MBR. Mechanisms of nutrient removal were studied and membrane fouling formation evaluated in terms of transmembrane pressure variation over time and sludge relative hydrophobicity. Furthermore, the impact of electrochemical processes on transparent exopolymeric particles (TEP), proposed as a new membrane fouling precursor, was investigated in addition to conventional fouling precursors such as bound extracellular polymeric substances (bEPS) and soluble microbial products (SMP). All the results indicate that the integration of electrochemical processes into a MBR has the advantage of improving the treatment performance especially in terms of nutrient removal, with an enhancement of orthophosphate (PO4-P) and ammonia nitrogen (NH4-N) removal efficiencies up to 96.06 and 69.34 %, respectively. A reduction of membrane fouling was also observed with an increase of floc hydrophobicity to 71.72 %, a decrease of membrane fouling precursor concentrations, and, thus, of membrane fouling rates up to 54.33 %. The relationship found between TEP concentration and membrane fouling rate after the application of electrochemical processes confirms the applicability of this parameter as a new membrane fouling indicator.

  11. Salts and nutrients present in regenerated waters induce changes in water relations, antioxidative metabolism, ion accumulation and restricted ion uptake in Myrtus communis L. plants.

    PubMed

    Acosta-Motos, José R; Alvarez, Sara; Barba-Espín, Gregorio; Hernández, José A; Sánchez-Blanco, María J

    2014-12-01

    The use of reclaimed water (RW) constitutes a valuable strategy for the efficient management of water and nutrients in landscaping. However, RW may contain levels of toxic ions, affecting plant production or quality, a very important aspect for ornamental plants. The present paper evaluates the effect of different quality RWs on physiological and biochemical parameters and the recovery capacity in Myrtus communis L. plants. M. communis plants were submitted to 3 irrigation treatments with RW from different sources (22 weeks): RW1 (1.7 dS m(-1)), RW2 (4.0 dS m(-1)) and RW3 (8.0 dS m(-1)) and one control (C, 0.8 dS m(-1)). During a recovery period of 11 weeks, all plants were irrigated with the control water. The RW treatments did not negatively affect plant growth, while RW2 even led to an increase in biomass. After recovery,only plants irrigated with RW3 showed some negative effects on growth, which was related to a decrease in the net photosynthesis rate, higher Na accumulation and a reduction in K levels. An increase in salinity was accompanied by decreases in leaf water potential, relative water content and gas exchange parameters, and increases in Na and Cl uptake. Plants accumulated Na in roots and restricted its translocation to the aerial part. The highest salinity levels produced oxidative stress, as seen from the rise in electrolyte leakage and lipid peroxidation. The use of regenerated water together with carefully managed drainage practices, which avoid the accumulation of salt by the substrate, will provide economic and environmental benefits.

  12. Interfacing carbon nanotubes (CNT) with plants: enhancement of growth, water and ionic nutrient uptake in maize ( Zea mays) and implications for nanoagriculture

    NASA Astrophysics Data System (ADS)

    Tiwari, D. K.; Dasgupta-Schubert, N.; Villaseñor Cendejas, L. M.; Villegas, J.; Carreto Montoya, L.; Borjas García, S. E.

    2014-06-01

    The application of nano-biotechnology to crop-science/agriculture (`nanoagriculture') is a recent development. While carbon nanotubes (CNTs) have been shown to dramatically improve germination of some comestible plants, deficiencies in consistency of behavior and reproducibility arise, partially from the variability of the CNTs used. In this work, factory-synthesized multi-walled-CNTs (MWCNTs) of quality-controlled specifications were seen to enhance the germinative growth of maize seedlings at low concentrations but depress it at higher concentrations. Growth enhancement principally arose through improved water delivery by the MWCNT. Polarized EDXRF spectrometry showed that MWCNTs affect mineral nutrient supply to the seedling through the action of the mutually opposing forces of inflow with water and retention in the medium by the ion-CNT transient-dipole interaction. The effect varied with ion type and MWCNT concentration. The differences of the Fe tissue concentrations when relatively high equimolar Fe2+ or Fe3+ was introduced, implied that the ion-CNT interaction might induce redox changes to the ion. The tissue Ca2+ concentration manifested as the antipode of the Fe2+ concentration indicating a possible cationic exchange in the cell wall matrix. SEM images showed that MWCNTs perforated the black-layer seed-coat that could explain the enhanced water delivery. The absence of perforations with the introduction of FeCl2/FeCl3 reinforces the idea of the modification of MWCNT functionality by the ion-CNT interaction. Overall, in normal media, low dose MWCNTs were seen to be beneficial, improving water absorption, plant biomass and the concentrations of the essential Ca, Fe nutrients, opening a potential for possible future commercial agricultural applications.

  13. Effectiveness of interventions that apply new media to improve vaccine uptake and vaccine coverage

    PubMed Central

    Odone, Anna; Ferrari, Antonio; Spagnoli, Francesca; Visciarelli, Sara; Shefer, Abigail; Pasquarella, Cesira; Signorelli, Carlo

    2014-01-01

    %), software for physicians and health professionals (n.4, 21%), and email communication (n.1, 5%). There is some evidence that text messaging, accessing immunization campaign websites, using patient-held web-based portals and computerized reminders increase immunization coverage rates. Insufficient evidence is available on the use of social networks, email communication and smartphone applications. Conclusion Although there is great potential for improving vaccine uptake and vaccine coverage by implementing programs and interventions that apply new media, scant data are available and further rigorous research - including cost-effectiveness assessments - is needed. PMID:25483518

  14. Effectiveness of interventions that apply new media to improve vaccine uptake and vaccine coverage.

    PubMed

    Odone, Anna; Ferrari, Antonio; Spagnoli, Francesca; Visciarelli, Sara; Shefer, Abigail; Pasquarella, Cesira; Signorelli, Carlo

    2015-01-01

    %), and email communication (n.1, 5%). There is some evidence that text messaging, accessing immunization campaign websites, using patient-held web-based portals and computerized reminders increase immunization coverage rates. Insufficient evidence is available on the use of social networks, email communication and smartphone applications. Although there is great potential for improving vaccine uptake and vaccine coverage by implementing programs and interventions that apply new media, scant data are available and further rigorous research - including cost-effectiveness assessments - is needed.

  15. A fast-start pacing strategy speeds pulmonary oxygen uptake kinetics and improves supramaximal running performance.

    PubMed

    Turnes, Tiago; Salvador, Amadeo Félix; Lisbôa, Felipe Domingos; de Aguiar, Rafael Alves; Cruz, Rogério Santos de Oliveira; Caputo, Fabrizio

    2014-01-01

    The focus of the present study was to investigate the effects of a fast-start pacing strategy on running performance and pulmonary oxygen uptake (VO2) kinetics at the upper boundary of the severe-intensity domain. Eleven active male participants (28±10 years, 70±5 kg, 176±6 cm, 57±4 mL/kg/min) visited the laboratory for a series of tests that were performed until exhaustion: 1) an incremental test; 2) three laboratory test sessions performed at 95, 100 and 110% of the maximal aerobic speed; 3) two to four constant speed tests for the determination of the highest constant speed (HS) that still allowed achieving maximal oxygen uptake; and 4) an exercise based on the HS using a higher initial speed followed by a subsequent decrease. To predict equalized performance values for the constant pace, the relationship between time and distance/speed through log-log modelling was used. When a fast-start was utilized, subjects were able to cover a greater distance in a performance of similar duration in comparison with a constant-pace performance (constant pace: 670 m±22%; fast-start: 683 m±22%; P = 0.029); subjects also demonstrated a higher exercise tolerance at a similar average speed when compared with constant-pace performance (constant pace: 114 s±30%; fast-start: 125 s±26%; P = 0.037). Moreover, the mean VO2 response time was reduced after a fast start (constant pace: 22.2 s±28%; fast-start: 19.3 s±29%; P = 0.025). In conclusion, middle-distance running performances with a duration of 2-3 min are improved and VO2 response time is faster when a fast-start is adopted.

  16. A Fast-Start Pacing Strategy Speeds Pulmonary Oxygen Uptake Kinetics and Improves Supramaximal Running Performance

    PubMed Central

    Turnes, Tiago; Salvador, Amadeo Félix; Lisbôa, Felipe Domingos; de Aguiar, Rafael Alves; Cruz, Rogério Santos de Oliveira; Caputo, Fabrizio

    2014-01-01

    The focus of the present study was to investigate the effects of a fast-start pacing strategy on running performance and pulmonary oxygen uptake () kinetics at the upper boundary of the severe-intensity domain. Eleven active male participants (28±10 years, 70±5 kg, 176±6 cm, 57±4 mL/kg/min) visited the laboratory for a series of tests that were performed until exhaustion: 1) an incremental test; 2) three laboratory test sessions performed at 95, 100 and 110% of the maximal aerobic speed; 3) two to four constant speed tests for the determination of the highest constant speed (HS) that still allowed achieving maximal oxygen uptake; and 4) an exercise based on the HS using a higher initial speed followed by a subsequent decrease. To predict equalized performance values for the constant pace, the relationship between time and distance/speed through log-log modelling was used. When a fast-start was utilized, subjects were able to cover a greater distance in a performance of similar duration in comparison with a constant-pace performance (constant pace: 670 m±22%; fast-start: 683 m±22%; P = 0.029); subjects also demonstrated a higher exercise tolerance at a similar average speed when compared with constant-pace performance (constant pace: 114 s±30%; fast-start: 125 s±26%; P = 0.037). Moreover, the mean response time was reduced after a fast start (constant pace: 22.2 s±28%; fast-start: 19.3 s±29%; P = 0.025). In conclusion, middle-distance running performances with a duration of 2–3 min are improved and response time is faster when a fast-start is adopted. PMID:25360744

  17. Wetland water and nutrient budget for improving irrigation performance in Caspian Low Lands, Iran

    NASA Astrophysics Data System (ADS)

    Sakadevan, Karuppan; Mousavi Shalmani, Mir Ahmad; Nguyen, Minh Long

    2014-05-01

    Water scarcity and uneven distribution of rainfall are the most important limiting factors for the development of agriculture in Iran. Assessment of sources and seasonal variations of wetland water and nutrient budget are fundamental for improving water quantity, quality and its agricultural use. This study was carried out in the Southern Caspian lowlands, Iran to identify sources of wetland water and establish water and nutrient budget for thirty wetlands from 2010 to 2012. Water samples collected in autumn, winter, spring and summer from these wetlands were (i) analysed for nitrogen (N), phosphorus (P) and isotopic signatures of oxygen-18 (δ18O) and hydrogen-2 (δ2H) and (ii) constructed for water and nutrient balance. In addition, groundwater (10-20 meters) rainwater, snow and wetland water were collected in spring 2013 and analysed for δ18O and δ2H. Results showed that wetland water was enriched with δ18O and δ2H in summer (-1.15‰ and -12.11‰ for δ18O and δ2H, respectively) and depleted in winter (-7.50‰ and -47.30‰ for δ18O and δ2H). This is probably due to spring snow melt, summer rainfall and evaporation of wetland water. As more water was used for irrigation in spring and summer, the water column depth reduced and accelerated evaporation leading to isotopic enrichment. Among various water sources, wetland water was enriched (-3.57‰ and -27.72‰ for δ18O and δ2H) compared to groundwater (-6.2‰ and -38.0‰ for δ18O and δ2H), rain water (-5.4‰ and -31.7‰ for δ18O and δ2H) and snow (-15.2‰ and -109.6‰ for δ18O and δ2H). Water and nutrient balance based on rainfall, evapotranspiration and nutrient concentrations for wetlands showed that on average 7.6 million cubic meters of water along with 86 tonnes of nitrogen (N) and 17 tonnes of phosphorus (P) can be captured from an area of 10,400 ha. This water can be used to irrigate up to 1500 ha rice crops over a period of 130 days in spring and summer. The isotopic signature and

  18. Angiogenesis in skeletal muscle precede improvements in peak oxygen uptake in peripheral artery disease patients.

    PubMed

    Duscha, Brian D; Robbins, Jennifer L; Jones, William S; Kraus, William E; Lye, R John; Sanders, John M; Allen, Jason D; Regensteiner, Judith G; Hiatt, William R; Annex, Brian H

    2011-11-01

    Peripheral artery disease (PAD) is characterized by impaired blood flow to the lower extremities, causing claudication and exercise intolerance. The mechanism(s) by which exercise training improves functional capacity is not understood. This study tested the hypothesis that in PAD patients who undergo supervised exercise training, increases in capillary density (CD) in calf muscle take place before improvements in peak oxygen uptake (VO(2)). Thirty-five PAD patients were randomly assigned to 12 weeks of directly supervised or home-based exercise training. Peak VO(2) testing and gastrocnemius muscle biopsies were performed at baseline and after training. CD (endothelial cells/mm(2)) was measured using immunofluorescence staining. After 3 weeks of directly supervised training, patients had an increase in CD (216±66 versus 284±77, P<0.01) but no increase in peak VO(2). However, after 12 weeks, peak VO(2) increased (15.3±2.8 versus 16.8±3.8, P<0.01), whereas in muscle, CD remained increased over baseline, but there were no changes in markers of oxidative capacity. Within subjects, CD was related to peak VO(2) before and after directly supervised training. Changes in CD in ischemic muscle with training may modulate the response to training, and those changes precede the increase in VO(2).

  19. Preparation of astaxanthin-loaded DNA/chitosan nanoparticles for improved cellular uptake and antioxidation capability.

    PubMed

    Wang, Qian; Zhao, Yingyuan; Guan, Lei; Zhang, Yaping; Dang, Qifeng; Dong, Ping; Li, Jing; Liang, Xingguo

    2017-07-15

    DNA/chitosan co-assemblies were initially used as nanocarriers for efficient astaxanthin encapsulation and delivery. The obtained astaxanthin-loaded DNA/chitosan (ADC) colloidal system was transparent and homogenous, with astaxanthin content up to 65μg/ml. Compared to free astaxanthin, ADC nanoparticles with an astaxanthin concentration as low as 3.35nM still showed a more powerful cytoprotective effect on H2O2-induced oxidative cell damage, and improved cell viability from 49.9% to 61.9%. The ROS scavenging efficiency of ADC nanoparticles was as high as 54.3%, which was 2-fold higher than that of free astaxanthin. Besides this, ADC nanoparticles were easily engulfed by Caco-2 cells in a short time, indicating that the encapsulated astaxanthin could be absorbed through endocytosis by intestinal epithelial cells. The improved antioxidation capability and facilitated cellular uptake enabled the ADC nanoparticles to be good candidates for efficient delivery and absorption of astaxanthin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Primary care strategies to improve childhood immunisation uptake in developed countries: systematic review

    PubMed Central

    Williams, Nia; Woodward, Helen; Majeed, Azeem; Saxena, Sonia

    2011-01-01

    Objectives To conduct a systematic review of strategies to optimize immunisation uptake within preschool children in developed countries. Design Systematic review. Setting Developed countries Participants Preschool children who were due, or overdue, one or more of their routine primary immunisations. Main outcome measures Increase in the proportion of the target population up to date with standard recommended universal vaccinations. Results Forty-six studies were included for analysis, published between 1980 and 2009. Twenty-six studies were randomized controlled trials, 11 were before and after trials, and nine were controlled intervention trials. Parental reminders showed a statistically significant increase in immunisation rates in 34% of included intervention arms. These effects were reported with both generic and specific reminders and with all methods of reminders and recall. Strategies aimed at immunisation providers were also shown to improve immunisation rates with a median change in immunisation rates of 7% when reminders were used, 8% when educational programmes were used and 19% when feedback programmes were used. Conclusion General practitioners are uniquely positioned to influence parental decisions on childhood immunisation. A variety of strategies studied in primary care settings have been shown to improve immunisation rates, including parental and healthcare provider reminders. PMID:22046500

  1. Nitrate uptake improvement by modified activated carbons developed from two species of pine cones.

    PubMed

    Nunell, G V; Fernandez, M E; Bonelli, P R; Cukierman, A L

    2015-02-15

    Activated carbons from two species of pine cones (Pinus canariensis and Cupressus sempervirens) were prepared by phosphoric acid activation and tested for the removal of nitrate ions from aqueous solution. To investigate the feasibility of improving their nitrate adsorption capacity, two different post-treatments—a thermal treatment and a treatment with saturated urea solution—were also applied to the prepared activated carbons. Comparison of the treated and untreated activated carbons showed that both post-treatments improved the nitrate adsorption performance more than twice. The maximum adsorption capacity, as evaluated from determination of the adsorption isotherms for the P. canariensis based carbons, and their proper representation by the Langmuir model, demonstrated that the post-treatment with the urea solution led to activated carbons with increased nitrate removal effectiveness, even superior to other reported results. Enhancements in their adsorption capacity could be mainly ascribed to higher contents of nitrogen and basic functional groups, whereas porous structure of the activated carbons did not seem to play a key role in the nitrate uptake.

  2. Improvements in growth performance, bone mineral status and nutrient digestibility in pigs following the dietary inclusion of phytase are accompanied by modifications in intestinal nutrient transporter gene expression.

    PubMed

    Vigors, Stafford; Sweeney, Torres; O'Shea, Cormac J; Browne, John A; O'Doherty, John V

    2014-09-14

    Phytase (PHY) improves growth performance, nutrient digestibility and bone structure in pigs; however, little is known about its effects on intestinal nutrient transporter gene expression. In the present study, a 44 d experiment was carried out using forty-eight pigs (11·76 (sem 0·75) kg) assigned to one of three dietary treatment groups to measure growth performance, coefficient of apparent ileal digestibility (CAID), coefficient of apparent total tract nutrient digestibility (CATTD) and intestinal nutrient transporter gene expression. Dietary treatments during the experimental period were as follows: (1) a high-P (HP) diet containing 3·4 g/kg available P and 7·0 g/kg Ca; (2) a low-P (LP) diet containing 1·9 g/kg available P and 5·9 g/kg Ca; (3) a PHY diet containing LP diet ingredients+1000 phytase units (FTU)/kg of PHY. The PHY diet increased the average daily gain (P< 0·05) and final body weight (P< 0·01) and decreased the feed conversion ratio (P< 0·05) compared with the LP diet. Pigs fed the PHY diet had a higher CAID of gross energy compared with those fed the HP and LP diets (P< 0·001). Pigs fed the PHY diet had increased CAID of P (P< 0·01) and CATTD of Ca and P (P< 0·001) compared with those fed the LP diet. The PHY diet increased the gene expression of the peptide transporter 1 (PEPT1/SLC15A1) (P< 0·05) in the ileum compared with the LP diet. The LP diet decreased the gene expression of the sodium-glucose-linked transporter 1 (SGLT1/SLC5A1) and GLUT2/SLC2A2 (P< 0·05) and increased the expression of membrane Ca channel (TRPV6) and calbindin compared with the HP diet (P< 0·001). In conclusion, feeding a diet supplemented with PHY improves growth performance and nutrient digestibility as well as increases the gene expression of the peptide transporter PEPT1.

  3. Preterm infants fed nutrient-enriched formula until 6 months show improved growth and development.

    PubMed

    Jeon, Ga Won; Jung, Yu Jin; Koh, Sun Young; Lee, Yeon Kyung; Kim, Kyung Ah; Shin, Son Moon; Kim, Sung Shin; Shim, Jae Won; Chang, Yun Sil; Park, Won Soon

    2011-10-01

    The purpose of the present study was to determine the effect of feeding nutrient-enriched preterm formula to preterm infants until 6 months' corrected age (CA) on growth and development in the first 18 months of life. Very low-birthweight preterm infants were fed preterm formula until term (40 weeks CA). Infants were then assigned to one of three groups and were fed term formula until 6 months' CA (group 1, n= 29); preterm formula to 3 months' CA and then term formula to 6 months' CA (group 2, n= 30); or preterm formula until 6 months' CA (group 3, n= 31). Anthropometry was performed at term, 3, 6, 9, 12, 15, and at s18 months' CA. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 months' CA. Although body weight, length, head circumference and z score for CA at term in group 3 were significantly lower than those of groups 1 and 2, growth rates of these parameters were significantly higher in group 3 up to 18 months CA', as compared to groups 1 and 2. The mental developmental index and psychomotor developmental index of the Bayley test were not significantly different between the three groups. Very low-birthweight preterm infants fed nutrient-enriched preterm formula until 6 months' CA demonstrated significantly improved growth rates for bodyweight, length and head circumference, and comparable mental and psychomotor development throughout the first 18 months of life. © 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

  4. Improved xylose uptake in Saccharomyces cerevisiae due to directed evolution of galactose permease Gal2 for sugar co-consumption.

    PubMed

    Reznicek, O; Facey, S J; de Waal, P P; Teunissen, A W R H; de Bont, J A M; Nijland, J G; Driessen, A J M; Hauer, B

    2015-07-01

    Saccharomyces cerevisiae does not express any xylose-specific transporters. To enhance the xylose uptake of S. cerevisiae, directed evolution of the Gal2 transporter was performed. Three rounds of error-prone PCR were used to generate mutants with improved xylose-transport characteristics. After developing a fast and reliable high-throughput screening assay based on flow cytometry, eight mutants were obtained showing an improved uptake of xylose compared to wild-type Gal2 out of 41 200 single yeast cells. Gal2 variant 2·1 harbouring five amino acid substitutions showed an increased affinity towards xylose with a faster overall sugar metabolism of glucose and xylose. Another Gal2 variant 3·1 carrying an additional amino acid substitution revealed an impaired growth on glucose but not on xylose. Random mutagenesis of the S. cerevisiae Gal2 led to an increased xylose uptake capacity and decreased glucose affinity, allowing improved co-consumption. Random mutagenesis is a powerful tool to evolve sugar transporters like Gal2 towards co-consumption of new substrates. Using a high-throughput screening system based on flow-through cytometry, various mutants were identified with improved xylose-transport characteristics. The Gal2 variants in this work are a promising starting point for further engineering to improve xylose uptake from mixed sugars in biomass. © 2015 The Society for Applied Microbiology.

  5. Fertilizer-dependent efficiency of Pseudomonads for improving growth, yield, and nutrient use efficiency of wheat (Triticum aestivum L.).

    PubMed

    Shaharoona, Baby; Naveed, Muhammad; Arshad, Muhammad; Zahir, Zahir A

    2008-05-01

    Acquisition of nutrients by plants is primarily dependent on root growth and bioavailability of nutrients in the rooting medium. Most of the beneficial bacteria enhance root growth, but their effectiveness could be influenced by the nutrient status around the roots. In this study, two 1-aminocyclopropane-1-carboxylate (ACC)-deaminase containing plant-growth-promoting rhizobacteria (PGPR), Pseudomonas fluorescens and P. fluorescens biotype F were tested for their effect on growth, yield, and nutrient use efficiency of wheat under simultaneously varying levels of all the three major nutrients N, P, and K (at 0%, 25%, 50%, 75%, and 100% of recommended doses). Results of pot and field trials revealed that the efficacy of these strains for improving growth and yield of wheat reduced with the increasing rates of NPK added to the soil. In most of the cases, significant negative linear correlations were recorded between percentage increases in growth and yield parameters of wheat caused by inoculation and increasing levels of applied NPK fertilizers. It is highly likely that under low fertilizer application, the ACC-deaminase activity of PGPR might have caused reduction in the synthesis of stress (nutrient)-induced inhibitory levels of ethylene in the roots through ACC hydrolysis into NH(3) and alpha-ketobutyrate. The results of this study imply that these Pseudomonads could be employed in combination with appropriate doses of fertilizers for better plant growth and savings of fertilizers.

  6. ApoA-IV improves insulin sensitivity and glucose uptake in mouse adipocytes via PI3K-Akt Signaling

    PubMed Central

    Li, Xiaoming; Wang, Fei; Xu, Min; Howles, Philip; Tso, Patrick

    2017-01-01

    Insulin resistance is a risk factor for type 2 diabetes mellitus. We investigated the effect of ApoA-IV on glucose uptake in the adipose and muscle tissues of mice and cultured 3T3-L1 adipocytes. We found that treatment with ApoA-IV lowered fasting blood glucose in both WT and diabetic KKAy mice by increasing glucose uptake in cardiac muscle, white adipose tissue, and brown adipose tissue through a mechanism that was partially insulin independent. Cell culture experiments showed that ApoA-IV improved glucose uptake in adipocytes in the absence of insulin by upregulating GLUT4 translocation by PI3K mediated activation of Akt signaling pathways. Considering our previous finding that ApoA-IV treatment enhanced pancreatic insulin secretion, these results suggests that ApoA-IV acts directly upon adipose tissue to improve glucose uptake and indirectly via insulin signaling. Our findings warrant future studies to identify the receptor for ApoA-IV and the downstream targets of PI3K-Akt signaling that regulate glucose uptake in adipocytes as potential therapeutic targets for treating insulin resistance. PMID:28117404

  7. An improved approach for remotely sensing water stress impacts on forest C uptake.

    PubMed

    Sims, Daniel A; Brzostek, Edward R; Rahman, Abdullah F; Dragoni, Danilo; Phillips, Richard P

    2014-09-01

    Given that forests represent the primary terrestrial sink for atmospheric CO2 , projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy 'greenness' (e.g., normalized difference vegetation index; NDVI). However, many forests have low spectral sensitivity to water stress (SSWS) - defined here as drought-induced decline in GPP without a change in greenness. Current satellite-derived estimates of GPP use a vapor pressure deficit (VPD) scalar to account for the low SWSS of forests, but fail to capture their responses to water stress. Our objectives were to characterize differences in SSWS among forested and nonforested ecosystems, and to develop an improved framework for predicting the impacts of water stress on GPP in forests with low SSWS. First, we paired two independent drought indices with NDVI data for the conterminous US from 2000 to 2011, and examined the relationship between water stress and NDVI. We found that forests had lower SSWS than nonforests regardless of drought index or duration. We then compared satellite-derived estimates of GPP with eddy-covariance observations of GPP in two deciduous broadleaf forests with low SSWS: the Missouri Ozark (MO) and Morgan Monroe State Forest (MMSF) AmeriFlux sites. Model estimates of GPP that used VPD scalars were poorly correlated with observations of GPP at MO (r(2) = 0.09) and MMSF (r(2) = 0.38). When we included the NDVI responses to water stress of adjacent ecosystems with high SSWS into a model based solely on temperature and greenness, we substantially improved predictions of GPP at MO (r(2) = 0.83) and for a severe drought year at the MMSF (r(2) = 0.82). Collectively, our results suggest that large-scale estimates of GPP that capture variation in SSWS among ecosystems could improve predictions of C uptake by forests under drought.

  8. Cultivation of Chlorella vulgaris in wastewater with waste glycerol: Strategies for improving nutrients removal and enhancing lipid production.

    PubMed

    Ma, Xiaochen; Zheng, Hongli; Addy, Min; Anderson, Erik; Liu, Yuhuan; Chen, Paul; Ruan, Roger

    2016-05-01

    To improve nutrients removal from wastewater and enhance lipid production, cultivation of Chlorella vulgaris in wastewater with waste glycerol generated from biodiesel production using scum derived oil as feedstock was studied. The results showed that nutrients removal was improved and lipid production of C. vulgaris was enhanced with the addition of waste glycerol into wastewater to balance its C/N ratio. The optimal concentration of the pretreated glycerol for C. vulgaris was 10gL(-1) with biomass concentration of 2.92gL(-1), lipid productivity of 163mgL(-1)d(-1), and the removal of 100% ammonia and 95% of total nitrogen. Alkaline conditions prompted cell growth and lipid accumulation of C. vulgaris while stimulating nutrients removal. The application of the integration process can lower both wastewater treatment and biofuel feedstock costs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. HYDRAULIC FRACTURING TO IMPROVE NUTRIENT AND OXYGEN DELIVERY FOR IN SITU BIORECLAMATION

    EPA Science Inventory

    The in situ delivery of nutrients and oxygen in soil is a serious problem in implementing in situ biodegradation. Current technology requires ideal site conditions to provide the remediating organisms with the nutrients and oxygen required for their metabolism, but...

  10. Improving fruit quality and phytochemical content through better nutrient management practices

    USDA-ARS?s Scientific Manuscript database

    Consumer preference quality traits (e.g. taste, texture) of muskmelons (Cucumis melo L.) and many other fruits are strongly influenced by cultivar as well as soil properties, such as soil type and nutrient supply capacity. Among nutrients, potassium (K) has the strongest influence on quality parame...

  11. HYDRAULIC FRACTURING TO IMPROVE NUTRIENT AND OXYGEN DELIVERY FOR IN SITU BIORECLAMATION

    EPA Science Inventory

    The in situ delivery of nutrients and oxygen in soil is a serious problem in implementing in situ biodegradation. Current technology requires ideal site conditions to provide the remediating organisms with the nutrients and oxygen required for their metabolism, but...

  12. Integrated soil-crop system management: reducing environmental risk while increasing crop productivity and improving nutrient use efficiency in China.

    PubMed

    Zhang, Fusuo; Cui, Zhenling; Fan, Mingsheng; Zhang, Weifeng; Chen, Xinping; Jiang, Rongfeng

    2011-01-01

    During the past 47 yr (1961-2007), Chinese cereal production has increased by 3.2-fold, successfully feeding 22% of the global human population with only 9% of the world's arable land, but at high environmental cost and resource consumption. Worse, crop production has been stagnant since 1996 while the population and demand for food continue to rise. New advances for sustainability of agriculture and ecosystem services will be needed during the coming 50 yr to reduce environmental risk while increasing crop productivity and improving nutrient use efficiency. Here, we advocate and develop integrated soil-crop system management (ISSM). In this approach, the key points are (i) to take all possible soil quality improvement measures into consideration, (ii) to integrate the utilization of various nutrient resources and match nutrient supply to crop requirements, and (iii) to integrate soil and nutrient management with high-yielding cultivation systems. Recent field experiments have shed light on how ISSM can lead to significant increases in crop yields while increasing nutrient use efficiency and reducing environmental risk.

  13. Composting of biochars improves their sorption properties, retains nutrients during composting and affects greenhouse gas emissions after soil application

    USDA-ARS?s Scientific Manuscript database

    Biochar application to soils has been suggested to elevate nutrient sorption, improve soil fertility and reduce net greenhouse gas (GHG) emissions. We examined the impact of composting biochar together with a biologically active substrate (i.e., livestock manure-straw mixture). We hypothesized that ...

  14. Ischemic preconditioning of the muscle improves maximal exercise performance but not maximal oxygen uptake in humans.

    PubMed

    Crisafulli, Antonio; Tangianu, Flavio; Tocco, Filippo; Concu, Alberto; Mameli, Ombretta; Mulliri, Gabriele; Caria, Marcello A

    2011-08-01

    Brief episodes of nonlethal ischemia, commonly known as "ischemic preconditioning" (IP), are protective against cell injury induced by infarction. Moreover, muscle IP has been found capable of improving exercise performance. The aim of the study was the comparison of standard exercise performances carried out in normal conditions with those carried out following IP, achieved by brief muscle ischemia at rest (RIP) and after exercise (EIP). Seventeen physically active, healthy male subjects performed three incremental, randomly assigned maximal exercise tests on a cycle ergometer up to exhaustion. One was the reference (REF) test, whereas the others were performed after the RIP and EIP sessions. Total exercise time (TET), total work (TW), and maximal power output (W(max)), oxygen uptake (VO(2max)), and pulmonary ventilation (VE(max)) were assessed. Furthermore, impedance cardiography was used to measure maximal heart rate (HR(max)), stroke volume (SV(max)), and cardiac output (CO(max)). A subgroup of volunteers (n = 10) performed all-out tests to assess their anaerobic capacity. We found that both RIP and EIP protocols increased in a similar fashion TET, TW, W(max), VE(max), and HR(max) with respect to the REF test. In particular, W(max) increased by ∼ 4% in both preconditioning procedures. However, preconditioning sessions failed to increase traditionally measured variables such as VO(2max), SV(max,) CO(max), and anaerobic capacity(.) It was concluded that muscle IP improves performance without any difference between RIP and EIP procedures. The mechanism of this effect could be related to changes in fatigue perception.

  15. Dopamine alleviates nutrient deficiency-induced stress in Malus hupehensis.

    PubMed

    Liang, Bowen; Li, Cuiying; Ma, Changqing; Wei, Zhiwei; Wang, Qian; Huang, Dong; Chen, Qi; Li, Chao; Ma, Fengwang

    2017-10-01

    Dopamine mediates many physiological processes in plants. We investigated its role in regulating growth, root system architecture, nutrient uptake, and responses to nutrient deficiencies in Malus hupehensis Rehd. Under a nutrient deficiency, plants showed significant reductions in growth, chlorophyll concentrations, and net photosynthesis, along with disruptions in nutrient uptake, transport, and distribution. However, pretreatment with 100 μM dopamine markedly alleviated such inhibitions. Supplementation with that compound enabled plants to maintain their photosynthetic capacity and development of the root system while promoting the uptake of N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, and B, altering the way in which those nutrients were partitioned throughout the plant. The addition of dopamine up-regulated genes for antioxidant enzymes involved in the ascorbate-glutathione cycle (MdcAPX, MdcGR, MdMDHAR, MdDHAR-1, and MdDHAR-2) but down-regulated genes for senescence (SAG12, PAO, and MdHXK). These results indicate that exogenous dopamine has an important antioxidant and anti-senescence effect that might be helpful for improving nutrient uptake. Our findings demonstrate that dopamine offers new opportunities for its use in agriculture, especially when addressing the problem of nutrient deficiencies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Biofortification of crops with nutrients: factors affecting utilization and storage.

    PubMed

    Díaz-Gómez, Joana; Twyman, Richard M; Zhu, Changfu; Farré, Gemma; Serrano, José Ce; Portero-Otin, Manuel; Muñoz, Pilar; Sandmann, Gerhard; Capell, Teresa; Christou, Paul

    2017-01-06

    Biofortification is an effective and economical method to improve the micronutrient content of crops, particularly staples that sustain human populations in developing countries. Whereas conventional fortification requires artificial additives, biofortification involves the synthesis or accumulation of nutrients by plants at source. Little is known about the relative merits of biofortification and artificial fortification in terms of nutrient bioaccessibility and bioavailability, and much depends on the biochemical nature of the nutrient, which can promote or delay uptake, and determine how efficiently different nutrients are transported through the blood, stored, and utilized. Data from the first plants biofortified with minerals and vitamins provide evidence that the way in which nutrients are presented can affect how they are processed and utilized in the human body. The latest studies on the effects of the food matrix, processing and storage on nutrient transfer from biofortified crops are reviewed, as well as current knowledge about nutrient absorption and utilization.

  17. Removal of nutrients from undiluted anaerobically treated piggery wastewater by improved microalgae.

    PubMed

    Wang, Mingzi; Yang, Yi; Chen, Zhihong; Chen, Yanzhen; Wen, Yangmin; Chen, Bilian

    2016-12-01

    This study aimed at improving the adaptability and biodegradability of tested microalgae in undiluted anaerobic fermentation slurry of piggery wastewater. For that, a two-stage method based on UV irradiation followed by gradual domestication was developed. The distinctness of this method was the elimination of a screening procedure and just needed the UV-irradiated cells with appropriate survival to be subjected to gradual domestication. The microalgae treated with the method not only grew well in undiluted slurry, but achieved outstanding removal efficiencies in total nitrogen (TN) and total phosphorus (TP). Large-scale application was conducted in an open raceway pond, and the concentrations of TN and TP after treatment were 43.80mg/L (removal rate of 89.5%) and 5.83mg/L (removal rate of 85.3%) respectively, which greatly excelled the Chinese discharge standards for livestock and poultry wastewater. The strategy is therefore a promising method for microalgae to purify piggery slurry containing high nutrient contents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Ectomycorrhizal symbiosis can enhance plant nutrition through improved access to discrete organic nutrient patches of high resource quality.

    PubMed

    Tibbett, M; Sanders, F E

    2002-06-01

    It is known that roots can respond to patches of fertility; however, root proliferation is often too slow to exploit resources fully, and organic nutrient patches may be broken down and leached, immobilized or chemically fixed before they are invaded by the root system. The ability of fungal hyphae to exploit resource patches is far greater than that of roots due to their innate physiological and morphological plasticity, which allows comprehensive exploration and rapid colonization of resource patches in soils. The fungal symbionts of ectomycorrhizal plants excrete significant quantities of enzymes such as chitinases, phosphatases and proteases. These might allow the organic residue to be tapped directly for nutrients such as N and P. Pot experiments conducted with nutrient-stressed ectomycorrhizal and control willow plants showed that when high quality organic nutrient patches were added, they were colonized rapidly by the ectomycorrhizal mycelium. These established willows (0.5 m tall) were colonized by Hebeloma syrjense P. Karst. for 1 year prior to nutrient patch addition. Within days after patch addition, colour changes in the leaves of the mycorrhizal plants (reflecting improved nutrition) were apparent, and after I month the concentration of N and P in the foliage of mycorrhizal plants was significantly greater than that in non-mycorrhizal plants subject to the same nutrient addition. It seems likely that the mycorrhizal plants were able to compete effectively with the wider soil microbiota and tap directly into the high quality organic resource patch via their extra-radical mycelium. We hypothesize that ectomycorrhizal plants may reclaim some of the N and P invested in seed production by direct recycling from failed seeds in the soil. The rapid exploitation of similar discrete, transient, high-quality nutrient patches may have led to underestimations when determining the nutritional benefits of ectomycorrhizal colonization.

  19. Effect of nitrogen rate and irrigation frequency on plant growth and nutrient uptake of container-grown Hydrangea macrophylla ‘Merritt’s Supreme’

    USDA-ARS?s Scientific Manuscript database

    The production of high quality container-grown nursery plants requires adequate but not excessive nutrients and water during production. Given the knowledge that N is the most important nutrient element for plant growth and that it is often the limiting factor, nursery growers tend to apply high lev...

  20. DHEA improves glucose uptake via activations of protein kinase C and phosphatidylinositol 3-kinase.

    PubMed

    Ishizuka, T; Kajita, K; Miura, A; Ishizawa, M; Kanoh, Y; Itaya, S; Kimura, M; Muto, N; Mune, T; Morita, H; Yasuda, K

    1999-01-01

    We have examined the effect of adrenal androgen, dehydroepiandrosterone (DHEA), on glucose uptake, phosphatidylinositol (PI) 3-kinase, and protein kinase C (PKC) activity in rat adipocytes. DHEA (1 microM) provoked a twofold increase in 2-[3H]deoxyglucose (DG) uptake for 30 min. Pretreatment with DHEA increased insulin-induced 2-[3H]DG uptake without alterations of insulin specific binding and autophosphorylation of insulin receptor. DHEA also stimulated PI 3-kinase activity. [3H]DHEA bound to purified PKC containing PKC-alpha, -beta, and -gamma. DHEA provoked the translocation of PKC-beta and -zeta from the cytosol to the membrane in rat adipocytes. These results suggest that DHEA stimulates both PI 3-kinase and PKCs and subsequently stimulates glucose uptake. Moreover, to clarify the in vivo effect of DHEA on Goto-Kakizaki (GK) and Otsuka Long-Evans fatty (OLETF) rats, animal models of non-insulin-dependent diabetes mellitus (NIDDM) were treated with 0.4% DHEA for 2 wk. Insulin- and 12-O-tetradecanoyl phorbol-13-acetate-induced 2-[3H]DG uptakes of adipocytes were significantly increased, but there was no significant increase in the soleus muscles in DHEA-treated GK/Wistar or OLETF/Long-Evans Tokushima (LETO) rats when compared with untreated GK/Wistar or OLETF/LETO rats. These results indicate that in vivo DHEA treatment can result in increased insulin-induced glucose uptake in two different NIDDM rat models.

  1. Incorporating redox processes improves prediction of carbon and nutrient cycling and greenhouse gas emission

    NASA Astrophysics Data System (ADS)

    Tang, Guoping; Zheng, Jianqiu; Yang, Ziming; Graham, David; Gu, Baohua; Mayes, Melanie; Painter, Scott; Thornton, Peter

    2016-04-01

    Among the coupled thermal, hydrological, geochemical, and biological processes, redox processes play major roles in carbon and nutrient cycling and greenhouse gas (GHG) emission. Increasingly, mechanistic representation of redox processes is acknowledged as necessary for accurate prediction of GHG emission in the assessment of land-atmosphere interactions. Simple organic substrates, Fe reduction, microbial reactions, and the Windermere Humic Aqueous Model (WHAM) were added to a reaction network used in the land component of an Earth system model. In conjunction with this amended reaction network, various temperature response functions used in ecosystem models were assessed for their ability to describe experimental observations from incubation tests with arctic soils. Incorporation of Fe reduction reactions improves the prediction of the lag time between CO2 and CH4 accumulation. The inclusion of the WHAM model enables us to approximately simulate the initial pH drop due to organic acid accumulation and then a pH increase due to Fe reduction without parameter adjustment. The CLM4.0, CENTURY, and Ratkowsky temperature response functions better described the observations than the Q10 method, Arrhenius equation, and ROTH-C. As electron acceptors between O2 and CO2 (e.g., Fe(III), SO42-) are often involved, our results support inclusion of these redox reactions for accurate prediction of CH4 production and consumption. Ongoing work includes improving the parameterization of organic matter decomposition to produce simple organic substrates, examining the influence of redox potential on methanogenesis under thermodynamically favorable conditions, and refining temperature response representation near the freezing point by additional model-experiment iterations. We will use the model to describe observed GHG emission at arctic and tropical sites.

  2. Affordable Nutrient Solutions for Improved Food Security as Evidenced by Crop Trials

    PubMed Central

    van der Velde, Marijn; See, Linda; You, Liangzhi; Balkovič, Juraj; Fritz, Steffen; Khabarov, Nikolay; Obersteiner, Michael; Wood, Stanley

    2013-01-01

    The continuing depletion of nutrients from agricultural soils in Sub-Saharan African is accompanied by a lack of substantial progress in crop yield improvement. In this paper we investigate yield gaps for corn under two scenarios: a micro-dosing scenario with marginal increases in nitrogen (N) and phosphorus (P) of 10 kg ha−1 and a larger yet still conservative scenario with proposed N and P applications of 80 and 20 kg ha−1 respectively. The yield gaps are calculated from a database of historical FAO crop fertilizer trials at 1358 locations for Sub-Saharan Africa and South America. Our approach allows connecting experimental field scale data with continental policy recommendations. Two critical findings emerged from the analysis. The first is the degree to which P limits increases in corn yields. For example, under a micro-dosing scenario, in Africa, the addition of small amounts of N alone resulted in mean yield increases of 8% while the addition of only P increased mean yields by 26%, with implications for designing better balanced fertilizer distribution schemes. The second finding was the relatively large amount of yield increase possible for a small, yet affordable amount of fertilizer application. Using African and South American fertilizer prices we show that the level of investment needed to achieve these results is considerably less than 1% of Agricultural GDP for both a micro-dosing scenario and for the scenario involving higher yet still conservative fertilizer application rates. In the latter scenario realistic mean yield increases ranged between 28 to 85% in South America and 71 to 190% in Africa (mean plus one standard deviation). External investment in this low technology solution has the potential to kick start development and could complement other interventions such as better crop varieties and improved economic instruments to support farmers. PMID:23565186

  3. Affordable nutrient solutions for improved food security as evidenced by crop trials.

    PubMed

    van der Velde, Marijn; See, Linda; You, Liangzhi; Balkovič, Juraj; Fritz, Steffen; Khabarov, Nikolay; Obersteiner, Michael; Wood, Stanley

    2013-01-01

    The continuing depletion of nutrients from agricultural soils in Sub-Saharan African is accompanied by a lack of substantial progress in crop yield improvement. In this paper we investigate yield gaps for corn under two scenarios: a micro-dosing scenario with marginal increases in nitrogen (N) and phosphorus (P) of 10 kg ha(-1) and a larger yet still conservative scenario with proposed N and P applications of 80 and 20 kg ha(-1) respectively. The yield gaps are calculated from a database of historical FAO crop fertilizer trials at 1358 locations for Sub-Saharan Africa and South America. Our approach allows connecting experimental field scale data with continental policy recommendations. Two critical findings emerged from the analysis. The first is the degree to which P limits increases in corn yields. For example, under a micro-dosing scenario, in Africa, the addition of small amounts of N alone resulted in mean yield increases of 8% while the addition of only P increased mean yields by 26%, with implications for designing better balanced fertilizer distribution schemes. The second finding was the relatively large amount of yield increase possible for a small, yet affordable amount of fertilizer application. Using African and South American fertilizer prices we show that the level of investment needed to achieve these results is considerably less than 1% of Agricultural GDP for both a micro-dosing scenario and for the scenario involving higher yet still conservative fertilizer application rates. In the latter scenario realistic mean yield increases ranged between 28 to 85% in South America and 71 to 190% in Africa (mean plus one standard deviation). External investment in this low technology solution has the potential to kick start development and could complement other interventions such as better crop varieties and improved economic instruments to support farmers.

  4. Improving fermented quality of cider vinegar via rational nutrient feeding strategy.

    PubMed

    Qi, Zhengliang; Dong, Die; Yang, Hailin; Xia, Xiaole

    2017-06-01

    This work aimed to find a rational nutrient feeding strategy for cider vinegar fermentation based on adequate information on the nutritional requirement of acetic acid bacteria. Through single nutrient lack experiment assay, necessary nutrient recipe for Acetobacter pasteurianus CICIM B7003 in acetous fermentation was confirmed. Compounds from the essential nutrient recipe were tested further to find out the key substrates significantly influencing cider vinegar fermentation. The findings showed that aspartate, glutamate, proline and tryptophan should be considered in detail for optimizing nutritional composition of cider. Finally, a nutrient feeding strategy that simultaneously adds proline, glutamate, aspartate and tryptophan to form final concentrations of 0.02g/L, 0.03g/L, 0.01g/L and 0.005g/L in cider was achieved by orthogonal experiment design. Comparing to the original fermentation, the yield of acetic acid from alcohol reached 93.3% and the concentration of most volatile flavor compounds increased with the rational nutrient feeding strategy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Biochar can be used to capture essential nutrients from dairy wastewater and improve soil physico-chemical properties

    NASA Astrophysics Data System (ADS)

    Ghezzehei, T. A.; Sarkhot, D. V.; Berhe, A. A.

    2014-09-01

    Recently, the potential for biochar use to recapture excess nutrients from dairy wastewater has been a focus of a growing number of studies. It is suggested that biochar produced from locally available excess biomass can be important in reducing release of excess nutrient elements from agricultural runoff, improving soil productivity, and long-term carbon (C) sequestration. Here we present a review of a new approach that is showing promise for the use of biochar for nutrient capture. Using batch sorption experiments, it has been shown that biochar can adsorb up to 20-43% of ammonium and 19-65% of the phosphate in flushed dairy manure in 24 h. These results suggest a potential of biochar for recovering essential nutrients from dairy wastewater and improving soil fertility if the enriched biochar is returned to soil. Based on the sorption capacity of 2.86 and 0.23 mg ammonium and phosphate, respectively, per gram of biochar and 10-50% utilization of available excess biomass, in the state of California (US) alone, 11 440 to 57 200 tonnes of ammonium-N and 920-4600 tonnes of phosphate can be captured from dairy waste each year while at the same time disposing up to 8-40 million tons of excess biomass.

  6. Peptide modified gold nanoparticles for improved cellular uptake, nuclear transport, and intracellular retention

    NASA Astrophysics Data System (ADS)

    Yang, C.; Uertz, J.; Yohan, D.; Chithrani, B. D.

    2014-09-01

    Gold nanoparticles (GNPs) are being extensively used in cancer therapeutic applications due to their ability to act both as an anticancer drug carrier in chemotherapy and as a dose enhancer in radiotherapy. The therapeutic response can be further enhanced if nanoparticles (NPs) can be effectively targeted into the nucleus. Here, we present an uptake and removal of GNPs functionalized with three peptides. The first peptide (RGD peptide) enhanced the uptake, the second peptide (NLS peptide) facilitated the nuclear delivery, while the third one (pentapeptide) covered the rest of the surface and protected it from the binding of serum proteins onto the NP surface. The pentapeptide also stabilized the conjugated GNP complex. The peptide-capped GNPs showed a five-fold increase in NP uptake followed by effective nuclear localization. The fraction of NPs exocytosed was less for peptide-capped NPs as compared to citrate-capped ones. Enhanced uptake and prolonged intracellular retention of peptide-capped GNPs could allow NPs to perform their desired applications more efficiently in cells. These studies will provide guidelines for developing NPs for therapeutic applications, which will require ``controlling'' of the NP accumulation rate while maintaining low toxicity.Gold nanoparticles (GNPs) are being extensively used in cancer therapeutic applications due to their ability to act both as an anticancer drug carrier in chemotherapy and as a dose enhancer in radiotherapy. The therapeutic response can be further enhanced if nanoparticles (NPs) can be effectively targeted into the nucleus. Here, we present an uptake and removal of GNPs functionalized with three peptides. The first peptide (RGD peptide) enhanced the uptake, the second peptide (NLS peptide) facilitated the nuclear delivery, while the third one (pentapeptide) covered the rest of the surface and protected it from the binding of serum proteins onto the NP surface. The pentapeptide also stabilized the conjugated GNP

  7. Factors influencing household uptake of improved solid fuel stoves in low- and middle-income countries: a qualitative systematic review.

    PubMed

    Debbi, Stanistreet; Elisa, Puzzolo; Nigel, Bruce; Dan, Pope; Eva, Rehfuess

    2014-08-13

    Household burning of solid fuels in traditional stoves is detrimental to health, the environment and development. A range of improved solid fuel stoves (IS) are available but little is known about successful approaches to dissemination. This qualitative systematic review aimed to identify factors that influence household uptake of IS in low- and middle-income countries. Extensive searches were carried out and studies were screened and extracted using established systematic review methods. Fourteen qualitative studies from Asia, Africa and Latin-America met the inclusion criteria. Thematic synthesis was used to synthesise data and findings are presented under seven framework domains. Findings relate to user and stakeholder perceptions and highlight the importance of cost, good stove design, fuel and time savings, health benefits, being able to cook traditional dishes and cleanliness in relation to uptake. Creating demand, appropriate approaches to business, and community involvement, are also discussed. Achieving and sustaining uptake is complex and requires consideration of a broad range of factors, which operate at household, community, regional and national levels. Initiatives aimed at IS scale up should include quantitative evaluations of effectiveness, supplemented with qualitative studies to assess factors affecting uptake, with an equity focus.

  8. Factors Influencing Household Uptake of Improved Solid Fuel Stoves in Low- and Middle-Income Countries: A Qualitative Systematic Review

    PubMed Central

    Debbi, Stanistreet; Elisa, Puzzolo; Nigel, Bruce; Dan, Pope; Eva, Rehfuess

    2014-01-01

    Household burning of solid fuels in traditional stoves is detrimental to health, the environment and development. A range of improved solid fuel stoves (IS) are available but little is known about successful approaches to dissemination. This qualitative systematic review aimed to identify factors that influence household uptake of IS in low- and middle-income countries. Extensive searches were carried out and studies were screened and extracted using established systematic review methods. Fourteen qualitative studies from Asia, Africa and Latin-America met the inclusion criteria. Thematic synthesis was used to synthesise data and findings are presented under seven framework domains. Findings relate to user and stakeholder perceptions and highlight the importance of cost, good stove design, fuel and time savings, health benefits, being able to cook traditional dishes and cleanliness in relation to uptake. Creating demand, appropriate approaches to business, and community involvement, are also discussed. Achieving and sustaining uptake is complex and requires consideration of a broad range of factors, which operate at household, community, regional and national levels. Initiatives aimed at IS scale up should include quantitative evaluations of effectiveness, supplemented with qualitative studies to assess factors affecting uptake, with an equity focus. PMID:25123070

  9. Hydrological improvements for nutrient and pollutant emission modeling in large scale catchments

    NASA Astrophysics Data System (ADS)

    Höllering, S.; Ihringer, J.

    2012-04-01

    An estimation of emissions and loads of nutrients and pollutants into European water bodies with as much accuracy as possible depends largely on the knowledge about the spatially and temporally distributed hydrological runoff patterns. An improved hydrological water balance model for the pollutant emission model MoRE (Modeling of Regionalized Emissions) (IWG, 2011) has been introduced, that can form an adequate basis to simulate discharge in a hydrologically differentiated, land-use based way to subsequently provide the required distributed discharge components. First of all the hydrological model had to comply both with requirements of space and time in order to calculate sufficiently precise the water balance on the catchment scale spatially distributed in sub-catchments and with a higher temporal resolution. Aiming to reproduce seasonal dynamics and the characteristic hydrological regimes of river catchments a daily (instead of a yearly) time increment was applied allowing for a more process oriented simulation of discharge dynamics, volume and therefore water balance. The enhancement of the hydrological model became also necessary to potentially account for the hydrological functioning of catchments in regard to scenarios of e.g. a changing climate or alterations of land use. As a deterministic, partly physically based, conceptual hydrological watershed and water balance model the Precipitation Runoff Modeling System (PRMS) (USGS, 2009) was selected to improve the hydrological input for MoRE. In PRMS the spatial discretization is implemented with sub-catchments and so called hydrologic response units (HRUs) which are the hydrotropic, distributed, finite modeling entities each having a homogeneous runoff reaction due to hydro-meteorological events. Spatial structures and heterogeneities in sub-catchments e.g. urbanity, land use and soil types were identified to derive hydrological similarities and classify in different urban and rural HRUs. In this way the

  10. Simple changes within dietary subgroups can rapidly improve the nutrient adequacy of the diet of French adults.

    PubMed

    Verger, Eric O; Holmes, Bridget A; Huneau, Jean François; Mariotti, François

    2014-06-01

    Identifying the dietary changes with the greatest potential for improving diet quality is critical to designing efficient nutrition communication campaigns. Our objective was to simulate the effects of different types of dietary substitutions to improve diet quality at the individual level. Starting from the observed diets of 1330 adults participating in the national French Nutrition and Health Survey (Etude Nationale Nutrition Santé), we simulated the effects of 3 different types of food and beverage substitutions with graded implementation difficulty for the consumer in a stepwise dietary counseling model based on the improvement in the PANDiet index, which measures diet quality in terms of nutrient adequacy. In scenario 1, substitutions of a food or beverage for its "lighter" version resulted in a modest improvement in the PANDiet score (Δ = +3.3 ± 0.1) and a decrease in energy intake (Δ = -114 ± 2 kcal/d). In scenario 2, substitutions of a food or beverage within the same food subgroup resulted in a marked improvement in the PANDiet score (Δ = +26.4 ± 0.2) with no significant change in energy intake. In this second scenario, the improvement in nutrient adequacy was due to substitutions in many subgroups, with no single subgroup contributing >8% to the increase in the PANDiet score. In scenario 3, substitutions of a food or beverage within the same food group resulted in the greatest improvement in the PANDiet score (Δ = +31.8 ± 0.2) but with an increase in energy intake (Δ = +204 ± 9 kcal/d). In this third scenario, the improvement in nutrient adequacy was largely due to substitutions of fish for meat and processed meat (∼30% of the increase in the PANDiet score). This study shows that a strategy based on simple substitutions within food subgroups is effective in rapidly improving the nutritional adequacy of the diet of French adults and could be used in public health nutrition actions.

  11. A Holistic Framework to Improve the Uptake and Impact of eHealth Technologies

    PubMed Central

    van Limburg, Maarten; Ossebaard, Hans C; Kelders, Saskia M; Eysenbach, Gunther; Seydel, Erwin R

    2011-01-01

    Background Many eHealth technologies are not successful in realizing sustainable innovations in health care practices. One of the reasons for this is that the current development of eHealth technology often disregards the interdependencies between technology, human characteristics, and the socioeconomic environment, resulting in technology that has a low impact in health care practices. To overcome the hurdles with eHealth design and implementation, a new, holistic approach to the development of eHealth technologies is needed, one that takes into account the complexity of health care and the rituals and habits of patients and other stakeholders. Objective The aim of this viewpoint paper is to improve the uptake and impact of eHealth technologies by advocating a holistic approach toward their development and eventual integration in the health sector. Methods To identify the potential and limitations of current eHealth frameworks (1999–2009), we carried out a literature search in the following electronic databases: PubMed, ScienceDirect, Web of Knowledge, PiCarta, and Google Scholar. Of the 60 papers that were identified, 44 were selected for full review. We excluded those papers that did not describe hands-on guidelines or quality criteria for the design, implementation, and evaluation of eHealth technologies (28 papers). From the results retrieved, we identified 16 eHealth frameworks that matched the inclusion criteria. The outcomes were used to posit strategies and principles for a holistic approach toward the development of eHealth technologies; these principles underpin our holistic eHealth framework. Results A total of 16 frameworks qualified for a final analysis, based on their theoretical backgrounds and visions on eHealth, and the strategies and conditions for the research and development of eHealth technologies. Despite their potential, the relationship between the visions on eHealth, proposed strategies, and research methods is obscure, perhaps due to a

  12. Improved laccase production by Funalia trogii in absorbent fermentation with nutrient carrier.

    PubMed

    Li, Guanhua; Liu, Xiaoxue; Yuan, Lin

    2017-10-01

    A novel strategy of enhancing laccase production by absorbent fermentation was investigated. Peanut shell was used as nutrient carrier for laccase production by Funalia trogii IFP0027 in the absorbent fermentation. The maximum laccase production was reached to 11,900 U/l, which was 4.97 times higher than that of the control group. The results indicated that carbohydrates and phenolic substances especially flavonoids contained in peanut shell stimulated laccase production by F. trogii. Meanwhile, the peanut shell nutrient carrier could not only alleviate the oxidative damage, owing to strong scavenging activity on hydroxyl, but also relieve the mechanical stresses to form small and regular microbial pellets. Therefore, the absorbent fermentation using peanut shell as nutrient carrier shows enormous potential in enhancing laccase production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Improved estimation of nitrogen uptake in grasslands using the nitrogen dilution curve

    USDA-ARS?s Scientific Manuscript database

    The critical nitrogen concentration (CNC) is a simple yet robust relationship that describes the changes in crop N during growth. We applied the concept of CNC to calculate N uptake across various cutting regimes. While it is well-established that decreasing cutting frequency changes growth rates, t...

  14. Arginine-tagging of polymeric nanoparticles via histidine to improve cellular uptake.

    PubMed

    Chiu, Jasper Z S; Tucker, Ian G; McLeod, Bernie J; McDowell, Arlene

    2015-01-01

    Polyarginine, a cell-penetrating peptide, has been shown to aid cellular penetration of bioactives into cells. We utilized a novel approach of using a histidine linker to produce poly(ethyl-cyanoacrylate) (PECA) nanoparticles tagged with oligoarginine and investigated cellular uptake. MALDI TOF/TOF (tandem) analysis revealed that di-arginine-histidine (RRH) covalently bound to PECA nanoparticles to form cationic particles (+18 mV), while longer oligoarginine peptides did not co-polymerize with PECA nanoparticles. Although RRH-tagged nanoparticles had similar size and FITC-dextran entrapment efficiency compared to unmodified nanoparticles, RRH-tagging of nanoparticles resulted in a greater release of FITC-dextran. As the nanoparticles were found to aggregate in Hanks Balanced Salt Solution (HBSS), the effect of phosphate on the zeta-potential of nanoparticles was studied. Treating the nanoparticles with poloxamer-407 prevented aggregation. RRH-tagged PECA nanoparticles increased cellular uptake by a further 30% compared to unmodified PECA nanoparticles and was concentration dependent. We suggest that enhanced cell uptake can be achieved using a di-arginine-histidine construct as opposed to the previously published findings that a minimum of hexa-arginine is necessary. Further, the cationic zeta-potential of the cell-penetrating peptide may not be needed to enhance uptake. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. DNAJB3/HSP-40 cochaperone improves insulin signaling and enhances glucose uptake in vitro through JNK repression

    PubMed Central

    Abu-Farha, Mohamed; Cherian, Preethi; Al-Khairi, Irina; Tiss, Ali; Khadir, Abdelkrim; Kavalakatt, Sina; Warsame, Samia; Dehbi, Mohammed; Behbehani, Kazem; Abubaker, Jehad

    2015-01-01

    Heat shock response (HSR) is an essential host-defense mechanism that is dysregulated in obesity-induced insulin resistance and type 2 diabetes (T2D). Our recent data demonstrated that DNAJB3 was downregulated in obese human subjects and showed negative correlation with inflammatory markers. Nevertheless, DNAJB3 expression pattern in diabetic subjects and its mode of action are not yet known. In this study, we showed reduction in DNAJB3 transcript and protein levels in PBMC and subcutaneous adipose tissue of obese T2D compared to obese non-diabetic subjects. Overexpression of DNAJB3 in HEK293 and 3T3-L1 cells reduced JNK, IRS-1 Ser-307 phosphorylation and enhanced Tyr-612 phosphorylation suggesting an improvement in IRS-1 signaling. Furthermore, DNAJB3 mediated the PI3K/AKT pathway activation through increasing AKT and AS160 phosphorylation. AS160 mediates the mobilization of GLUT4 transporter to the cell membrane and thereby improves glucose uptake. Using pre-adipocytes cells we showed that DNAJB3 overexpression caused a significant increase in the glucose uptake, possibly through its phosphorylation of AS160. In summary, our results shed the light on the possible role of DNAJB3 in improving insulin sensitivity and glucose uptake through JNK repression and suggest that DNAJB3 could be a potential target for therapeutic treatment of obesity-induced insulin resistance. PMID:26400768

  16. Root-targeted hormonal biotechnology to improve crop stress tolerance

    USDA-ARS?s Scientific Manuscript database

    Since plant root systems capture both water and nutrients essential for the formation of crop yield, there has been renewed biotechnological focus on root system improvement. Although water and nutrient uptake can be facilitated by membrane proteins known as aquaporins and nutrient transporters resp...

  17. Mitochondrial alternative oxidase acts to dampen the generation of active oxygen species during a period of rapid respiration induced to support a high rate of nutrient uptake.

    PubMed

    Yip, Justine Y. H.; Vanlerberghe, Greg C.

    2001-07-01

    When wild type (wt) tobacco (Nicotiana tabacum L. cv. Petit Havana SR1) suspension cells were grown under phosphate (P) limitation, they contained large amounts of mitochondrial alternative oxidase (AOX). When these cells were resupplied with P, there was a large, immediate and sustained stimulation of respiration to support a period of rapid P uptake. Two lines of evidence suggest that the abundant level of AOX present in wt cells contributed to this stimulated rate of respiration. First, when P-limited transgenic antisense tobacco cells (AS8) lacking AOX were resupplied with P, the stimulation of respiration was much less dramatic even though these cells displayed similar rates of P uptake. Second, while the stimulated rate of respiration in AS8 cells was insensitive (as expected) to the AOX inhibitor n-propyl gallate (nPG), much of the stimulated rate of respiration in wt cells could be inhibited by nPG. Given the non-phosphorylating nature of AOX respiration, wt cells required higher rates of electron transport to O2 than AS8 cells to support similar rates of P uptake. The utilization of AOX by wt cells during P uptake was apparently not occurring because the cytochrome (Cyt) pathway alone could not fully support the rate of P uptake, as the respiration of cells lacking AOX (either untreated AS8 cells or wt cells treated with nPG) supported similar rates of P uptake as wt cells with abundant AOX. Rather, we provide in vivo evidence that the utilization of AOX during the period of high respiration supporting P uptake was to dampen the mitochondrial generation of active oxygen species (AOS).

  18. Evaluation of a service intervention to improve awareness and uptake of bowel cancer screening in ethnically-diverse areas

    PubMed Central

    Shankleman, J; Massat, N J; Khagram, L; Ariyanayagam, S; Garner, A; Khatoon, S; Rainbow, S; Rangrez, S; Colorado, Z; Hu, W; Parmar, D; Duffy, S W

    2014-01-01

    Background: Uptake of bowel cancer screening is lowest in London, in populations of lower socio-economic status, and in particular ethnic or religious groups. Methods: We report on the evaluation of two interventions to improve uptake in an area including populations of low socio-economic status and considerable ethnic diversity. The interventions were face-to-face health promotion on bowel cancer screening at invitees' general practice and health promotion delivered by telephone only. Nine large general practices in East London were chosen at random to offer face-to-face health promotion, and nine other large practices to offer telephone health promotion, with 24 practices of similar size as comparators. Data at practice level were analysed by Mann–Whitney–Wilcoxon tests and grouped-logistic regression. Results: There were 2034 invitees in the telephone intervention practices, 1852 in the face-to-face intervention practices and 5227 in the comparison practices. Median gFOBt kit uptake in the target population (aged 59–70) was 46.7% in the telephone practices, 43.8% in the face-to-face practices and 39.1% in the comparison practices. Significant improvements in the odds of uptake were observed following telephone intervention in both males (OR=1.39, 95% CI=1.20–1.61, P<0.001) and females (OR=1.49, 95% CI=1.29–1.73, P<0.001), while the face-to-face intervention mainly impacted uptake in males (OR=1.23, 95% CI=1.10–1.36), P<0.001) but did not lead to a significant increase in females (OR=1.12, 95% CI=0.96–1.29, P=0.2). Conclusions: Personally delivered health promotion improved uptake of bowel cancer screening in areas of low socio-economic status and high ethnic diversity. The intervention by telephone appears to be the most effective method. PMID:24983374

  19. Intervention leads to improvements in the nutrient profile of snacks served in afterschool programs: a group randomized controlled trial.

    PubMed

    Beets, Michael W; Turner-McGrievy, Brie; Weaver, R Glenn; Huberty, Jennifer; Moore, Justin B; Ward, Dianne S; Freedman, Darcy A

    2016-09-01

    Widely adopted nutrition policies for afterschool programs (ASPs) focus on serving a fruit/vegetable daily and eliminating sugar-sweetened foods/beverages. The impact of these policies on the nutrient profile of snacks served is unclear. Evaluate changes in macro/micronutrient content of snacks served in ASPs. A 1-year group randomized controlled trial was conducted in 20 ASPs serving over 1700 elementary-age children. Intervention ASPs received a multistep adaptive framework intervention. Direct observation of snack served was collected and nutrient information determined using the USDA Nutrient Database, standardized to nutrients/100 kcal. By post-assessment, intervention ASPs reduced total kcal/snack served by 66 kcal (95CI -114 to -19 kcal) compared to control ASPs. Total fiber (+1.7 g/100 kcal), protein (+1.4 g/100 kcal), polyunsaturated fat (+1.2 g/100 kcal), phosphorous (+49.0 mg/100 kcal), potassium (+201.8 mg/100 kcal), and vitamin K (+21.5 μg/100 kcal) increased in intervention ASPs, while added sugars decreased (-5.0 g/100 kcal). Nutrition policies can lead to modest daily caloric reductions and improve select macro/micronutrients in snacks served. Long-term, these nutritional changes may contribute to healthy dietary habits.

  20. Use of lipid-based nutrient supplements (LNS) to improve the nutrient adequacy of general food distribution rations for vulnerable sub-groups in emergency settings.

    PubMed

    Chaparro, Camila M; Dewey, Kathryn G

    2010-01-01

    The term 'lipid-based nutrient supplements' (LNS) refers generically to a range of fortified, lipid-based products, including products like Ready-to-Use Therapeutic Foods (RUTF) (a large daily ration with relatively low micronutrient concentration) as well as highly concentrated supplements (1-4 teaspoons/day, providing <100 kcal/day) to be used for 'point-of-use' fortification. RUTF have been successfully used for the management of severe acute malnutrition (SAM) among children in emergency settings. Recent research on smaller doses of LNS for prevention of malnutrition has created interest in their potential use in emergency settings to ensure a more nutritionally adequate ration for the most vulnerable groups [e.g. infants and children between 6 and 24 months of age, and pregnant and lactating women (PLW)]. Currently, the main food and nutrition interventions in emergency settings include general food distribution (GFD) rations, which are provided to the affected population as a whole, and selective (or supplementary) feeding programs (SFP), which are to be provided to nutritionally vulnerable or malnourished individuals. In addition to logistical and operational challenges that may limit the intended effect of these programs, the nutritional quality of the food commodities provided may be insufficient to meet the needs of infants and young children and PLW. Because these subgroups have particularly high nutrient needs for growth and development, meeting these needs is challenging in settings where the ration is limited to a few food commodities, with little access to a diverse diet and bioavailable sources of micronutrients. In recent years, there has been increased attention to adding micronutrient interventions, on top of the other food-based interventions (such as GFDs and SFPs), to fill micronutrient gaps in diets in emergency settings. The focus of this document is the potential role of LNS in meeting the nutritional needs of these vulnerable subgroups

  1. Minor nutrients are critical for the improved growth of Corylus avellana shoot cultures

    USDA-ARS?s Scientific Manuscript database

    Many hazelnut (Corylus avellana L.) cultivars fail to thrive on standard growth media and the reasons for poor growth are not well understood. Our initial study of five C. avellana cultivars showed that changes in the mineral nutrients of Driver and Kuniyuki Walnut (DKW) medium, including doubling t...

  2. Revising the paradigm for improved nutrient management on Australian dairy farms.

    USDA-ARS?s Scientific Manuscript database

    Dairy operations in Australia continue to intensify. Farm numbers are declining, while milk production per cow, and reliance on imported feed, are all increasing. As a result, nutrient surpluses within the dairy landscape are a common problem in Australia and pose an increasing threat to the environ...

  3. Meta-analysis constrained by data: Recommendations to improve relevance of nutrient management research

    USDA-ARS?s Scientific Manuscript database

    Five research teams received funding through the North American 4R Research Fund to conduct meta-analyses of the air and water quality impacts of on-farm 4R nutrient management practices. In compiling or expanding databases for these analyses on environmental and crop production effects, researchers...

  4. Affordable nutrient solutions for improved food security as evidenced by crop trials

    NASA Astrophysics Data System (ADS)

    van der Velde, Marijn; See, Linda; You, Liangzhi; Balkovic, Juraj; Fritz, Steffen; Khabarov, Nikolay; Obersteiner, Michael; Wood, Stanley

    2013-04-01

    Robust assessments of attainable crop yields in Africa and South America are pivotal for projections of food security and cropland expansion. In contract to South America, Africa has not achieved significant increases in crop yields. Here we utilize a database of historical FAO crop fertilizer trials at 1358 locations for Sub-Saharan Africa and South America to calculate corn yield gaps at the continental scale. To further the African crop productivity discourse we consider the importance of soil nutrient stoichiometry and the viability of micro-dosing. Importantly, besides N, our crop yield potential estimates account for P which has a notoriously low availability in weathered tropical soils. We investigated yield gaps for corn under two scenarios: a micro-dosing scenario with marginal increases in N and P of 10 kg/ha and a larger yet still conservative scenario with proposed N and P applications of 80 and 20 kg/ha respectively. Two critical findings emerged from the analysis. The first is the degree to which P limits increases in corn yields. For example, under a micro-dosing scenario, in Africa, the addition of small amounts of N alone resulted in yield increases of 8% while the addition of only P increased yields by 26%, with implications for designing better balanced fertilizer distribution schemes. Application of both N and P at 10 kg ha-1 lead to 15% and 32% yield increase. To put the benefits of these higher yields in context, this could save more than 4 and 25 million ha of cropland, or alternatively potentially feed 64 and 150 million people in South America and Africa respectively. The second finding was the relatively large amount of yield increase possible for a small, yet affordable amount of fertilizer application. Using African and South American fertilizer prices we show that the level of investment needed to achieve these results is considerably less than 1% of Agricultural GDP for both a micro-dosing scenario and for a scenario involving higher

  5. Improving solubility, stability, and cellular uptake of resveratrol by nanoencapsulation with chitosan and γ-poly (glutamic acid).

    PubMed

    Jeon, Young Ok; Lee, Ji-Soo; Lee, Hyeon Gyu

    2016-11-01

    Resveratrol (RES), a polyphenolic compound found in grape skins, is a potent antioxidant with broad health benefits. However, its utilization in food has been limited by its poor water solubility, instability, and low bioavailability. The purpose of this study is to improve the solubility, stability, and cellular uptake of RES by nanoencapsulation using chitosan (CS) and γ-poly (glutamic acid) (γ-PGA). The size of nanoparticles significantly decreases with a decrease in the CS/γ-PGA ratio (p<0.05). The nanoparticle size with CS/γ-PGA ratio of 5 was 100-150nm. The entrapment efficiency and UV-light protection effect significantly increases (p<0.05), with an increase in the CS and γ-PGA concentration. The solubility of RES increases 3.2 and 4.2 times before and after lyophilization by nanoencapsulation, respectively. Compared with non-nanoencapsulated RES, the nanoencapsulated RES tends to maintain its solubility and antioxidant activity during storage. CS/γ-PGA nanoencapsulation was able to significantly enhance the transport of RES across a Caco-2 cell monolayer (p<0.05). The highest cellular uptake was found for nanoparticles prepared with 0.5mg/mL CS and 0.1mg/mL γ-PGA, which showed the highest solubility and antioxidant activity during storage. Therefore, CS/γ-PGA nanoencapsulation is found to be a potentially valuable technique for improving the solubility, stability, and cellular uptake of RES.

  6. Ammonium and nitrate uptake, nitrogen productivity and biomass allocation in interior spruce families with contrasting growth rates and mineral nutrient preconditioning.

    PubMed

    Miller, Brad D; Hawkins, Barbara J

    2007-06-01

    Four full-sib families of interior spruce (Picea glauca (Moench) Voss) x Picea engelmanii Parry ex Engelm.) with contrasting growth rates (two fast-growing and two slow-growing families) were grown aeroponically with either a 2% relative nitrogen addition rate or free access to nitrogen. Fast-growing families showed greater plasticity in allocating biomass to shoots at high nitrogen supply and to roots at low nitrogen supply than slow-growing families. Compared with the slow-growing families, short-term net ammonium uptake rate measured with an ion selective electrode was significantly greater in fast-growing families at high ammonium supply, but not at low supply. Net nitrate uptake showed the same trend, but differences among families were not significant. Results indicate that differences in seedling growth rate are partly a result of physiological differences in net nitrogen uptake efficiency and nitrogen productivity.

  7. Childhood immunisation in Bungoma County, Kenya, from 2008 to 2011: need for improved uptake.

    PubMed

    Mbuthia, G W; Harries, A D; Obala, A A; Nyamogoba, H D N; Simiyu, C; Edginton, M E; Khogali, M; Hedt-Gauthier, B L; Otsyla, B K

    2014-03-21

    Uptake of immunisations in children aged 1-2 years in Bungoma County, Kenya, was determined as part of the 6-monthly Health and Demographic Surveillance System surveys. A total of 2699 children were assessed between 2008 and 2011. During this time period, full immunisation declined significantly from 84% to 58%, and measles vaccine declined uptake from 89% to 60% (P < 0.001). Each year there was a significant fall-off for the third doses of the oral polio and pentavalent vaccines (P < 0.001). These findings are of concern, as low immunisation coverage may lead to vaccine-preventable disease outbreaks. Further investigations into the reasons for declining immunisation trends are required.

  8. Exploration of Metal Chloride Uptake for Improved Performance Characteristics of PbSe Quantum Dot Solar Cells

    SciTech Connect

    Marshall, Ashley R.; Young, Matthew R.; Nozik, Arthur J.; Beard, Matthew C.; Luther, Joseph M.

    2015-08-06

    We explored the uptake of metal chloride salts with +1 to +3 metals of Na+, K+, Zn2+, Cd2+, Sn2+, Cu2+, and In3+ by PbSe QD solar cells. We also compared CdCl2 to Cd acetate and Cd nitrate treatments. PbSe QD solar cells fabricated with a CdCl2 treatment are stable for more than 270 days stored in air. We studied how temperature and immersion times affect optoelectronic properties and photovoltaic cell performance. Uptake of Cd2+ and Zn2+ increase open circuit voltage, whereas In3+ and K+ increase the photocurrent without influencing the spectral response or first exciton peak position. Using the most beneficial treatments we varied the bandgap of PbSe QD solar cells from 0.78 to 1.3 eV and find the improved VOC is more prevalent for lower bandgap QD solar cells.

  9. Multifunctional non-viral gene vectors with enhanced stability, improved cellular and nuclear uptake capability, and increased transfection efficiency

    NASA Astrophysics Data System (ADS)

    Yang, Zhe; Jiang, Zhaozhong; Cao, Zhong; Zhang, Chao; Gao, Di; Luo, Xingen; Zhang, Xiaofang; Luo, Huiyan; Jiang, Qing; Liu, Jie

    2014-08-01

    We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell for nanoparticle stabilization, poly(γ-glutamic acid) (γ-PGA) and mTAT (a cell-penetrating peptide) for accelerated cellular uptake, and a nuclear localization signal peptide (NLS) for enhanced intracellular transport of DNA to the nucleus. In vitro study showed that coating of the binary PPMS/DNA polyplex with γ-PGA promotes cellular uptake of the polyplex particles, particularly by γ-glutamyl transpeptidase (GGT)-positive cells through the GGT-mediated endocytosis pathway. Conjugating PEG to the γ-PGA led to the formation of a ternary PPMS/DNA/PGA-g-PEG polyplex with decreased positive charges on the surface of the polyplex particles and substantially higher stability in serum-containing aqueous medium. The cellular uptake rate was further improved by incorporating mTAT into the ternary polyplex system. Addition of the NLS peptide was designed to facilitate intracellular delivery of the plasmid to the nucleus--a rate-limiting step in the gene transfection process. As a result, compared with the binary PPMS/LucDNA polyplex, the new mTAT-quaternary PPMS/LucDNA/NLS/PGA-g-PEG-mTAT system exhibited reduced cytotoxicity, remarkably faster cellular uptake rate, and enhanced transport of DNA to the nucleus. All these advantageous functionalities contribute to the remarkable gene transfection efficiency of the mTAT-quaternary polyplex both in vitro and in vivo, which exceeds that of the binary polyplex and commercial Lipofectamine™ 2000/DNA lipoplex. The multifunctional mTAT-quaternary polyplex system with improved efficiency and reduced cytotoxicity represents a new type of promising non-viral vectors for the delivery of therapeutic genes to treat tumors.We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell

  10. Exploration of Metal Chloride Uptake for Improved Performance Characteristics of PbSe Quantum Dot Solar Cells.

    PubMed

    Marshall, Ashley R; Young, Matthew R; Nozik, Arthur J; Beard, Matthew C; Luther, Joseph M

    2015-08-06

    We explored the uptake of metal chloride salts with +1 to +3 metals of Na(+), K(+), Zn(2+), Cd(2+), Sn(2+), Cu(2+), and In(3+) by PbSe QD solar cells. We also compared CdCl2 to Cd acetate and Cd nitrate treatments. PbSe QD solar cells fabricated with a CdCl2 treatment are stable for more than 270 days stored in air. We studied how temperature and immersion times affect optoelectronic properties and photovoltaic cell performance. Uptake of Cd(2+) and Zn(2+) increase open circuit voltage, whereas In(3+) and K(+) increase the photocurrent without influencing the spectral response or first exciton peak position. Using the most beneficial treatments we varied the bandgap of PbSe QD solar cells from 0.78 to 1.3 eV and find the improved VOC is more prevalent for lower bandgap QD solar cells.

  11. Arbuscular mycorrhizae formed by Penicillium pinophilum improve the growth, nutrient uptake and photosynthesis of strawberry with two inoculum-types.

    PubMed

    Fan, Yongqiang; Luan, Yushi; An, Lijia; Yu, Kun

    2008-08-01

    Penicillium pinophilum was isolated from the soil in a commercial strawberry field. The strain readily formed arbuscular mycorrhizae (AM) with the roots of strawberry 'Zoji' (Fragaria x ananassa Duch. CV.) when plants were inoculated with either fresh cultured hyphae or root/soil mixtures. Fresh hyphae, however, resulted in higher amounts of colonization than root/soil inoculum. Compared with uninoculated strawberries, inoculation increased plant dry weight by 31%, as well as nitrogen content (47%), phosphorus content (57%), and photosynthetic rate (71%). AM inoculation also shortened the blossom and ripening date by 3 and 4 days, respectively. This is the first report of a P. pinophilum strain resulting in mycorrhiza with strawberry roots. The significant advantages of this strain are that it is easy to culture and inoculation of plants results in significant growth benefits that may be useful in strawberry production.

  12. Ambient and elevated carbon dioxide on growth, physiological and nutrient uptake parameters of perennial leguminous cover crops under low light intensities

    USDA-ARS?s Scientific Manuscript database

    Adaptability and optimum growth of cover crops in plantation crops is affected by the inherent nature of the cover crop species and the light intensity at canopy levels. Globally concentrations of atmospheric CO2 are increasing and this creates higher photosynthesis and nutrient demand by crops as l...

  13. Technical Note: Testing an improved index for analysing storm nutrient hysteresis

    NASA Astrophysics Data System (ADS)

    Lloyd, C. E. M.; Freer, J. E.; Johnes, P. J.; Collins, A. L.

    2015-08-01

    Analysis of hydrochemical behaviour in extreme flow events can provide new insights into the process controls on nutrient transport in catchments. The examination of storm behaviours using hysteresis analysis has increased in recent years, partly due to the increased availability of high temporal resolution datasets for discharge and nutrient parameters. A number of these analyses involve the use of an index to describe the characteristics of a hysteresis loop in order to compare different storm behaviours both within and between catchments. This technical note reviews the methods for calculation of the hysteresis index (HI) and explores a new more effective methodology. Each method is systematically tested and the impact of the chosen calculation on the results is examined. Recommendations are made regarding the most effective method of calculating a HI which can be used for comparing data between storms and between different parameters and catchments.

  14. Determining ecologically acceptable nutrient loads to natural wetlands for water quality improvement.

    PubMed

    Keenan, L W; Lowe, E F

    2001-01-01

    Natural wetlands often function as nutrient sinks, reducing nutrient inputs into lakes and streams. P loading from anthropogenic sources has significantly affected many natural wetlands. This paper describes a method to determine an acceptable P load to natural wetlands based on ecological principles. This approach can be used to determine how much P can be assimilated without diminishing species diversity and, thereby, sets a limit for cultural eutrophication of natural wetlands. The basis for determining an acceptable load is management of risk to species diversity by determination of the maximum area of a wetland that can be put at risk while preserving biodiversity of the overall wetland system. Two cases are distinguished: 1) simple-stress, where growth of the affected area immediately increases risks for species loss, and 2) subsidy-stress, where growth of the affected area first benefits then diminishes net species diversity.

  15. Curcumin-loaded solid lipid nanoparticles have prolonged in vitro antitumour activity, cellular uptake and improved in vivo bioavailability.

    PubMed

    Sun, Jiabei; Bi, Chao; Chan, Hok Man; Sun, Shaoping; Zhang, Qingwen; Zheng, Ying

    2013-11-01

    The aim of the present study was to blend liquid lipids with solid lipids to encapsulate curcumin in solid lipid nanoparticles (SLNs), thereby improving the dispersibility and chemical stability of curcumin, prolonging its antitumour activity and cellular uptake and enhancing its bioavailability. Curcumin-loaded SLNs (C-SLNs) were prepared by high-pressure homogenisation with liquid lipid Sefsol-218(®). The morphology, stability and release of curcumin in the optimised formulation were investigated. The anti-cancer activity of the formulation was evaluated in MCF-7 cells. Fluorescence spectrophotometry was used to quantify cellular uptake of the drug. The pharmacokinetic profiles of curcumin in SLNs after intravenous administration were studied in rats. Blending Sefsol-218(®) into a lipid matrix reduced the particle size without improving drug loading. An optimised formulation consisting of Dynasan 114(®), Sefsol-218(®), and Pluronic F68(®) (630:70:300, w/w) loaded with 0.8% drug was prepared. This formulation could be dispersed in water with a mean particle size of 152.8 ± 4.7 nm and a 90% entrapment efficiency. Curcumin displayed a two-phase sustained release profile from C-SLNs with improved chemical stability. Compared to the solubilised solution, C-SLNs exhibited prolonged inhibitory activity in cancer cells, as well as time-dependent increases in intracellular uptake. After intravenous administration to rats, the bioavailability of curcumin was increased by 1.25-fold. C-SLNs with improved dispersibility and chemical stability in an aqueous system have been successfully developed. C-SLNs may represent a potentially useful cancer therapeutic curcumin delivery system. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Engaging parents and schools improves uptake of the human papillomavirus (HPV) vaccine: examining the role of the public health nurse.

    PubMed

    Whelan, Noella W; Steenbeek, Audrey; Martin-Misener, Ruth; Scott, Jeffrey; Smith, Bruce; D'Angelo-Scott, Holly

    2014-08-06

    Nova Scotia has the highest rate of cervical cancer in Canada, and most of these cases are attributed to the Human Papillomavirus (HPV). In 2007, Gardasil(®) was approved and implemented in a successful school-based HPV immunization program. Little is known, however, which strategies (if any) used within a school-based program help to improve vaccine uptake. A retrospective, exploratory correlation study was conducted to examine the relationship between school-based strategies and uptake of HPV vaccine. Data was analyzed through Logistic regression, using PASW Statistics 17 (formerly SPSS 17). HPV vaccine initiation was significantly associated with Public Health Nurses providing reminder calls for: consent return (p=0.017) and missed school clinic (p=0.004); HPV education to teachers (p<0.001), and a thank-you note to teachers (p<0.001). Completion of the HPV series was associated with vaccine consents being returned to the students' teacher (p=0.003), and a Public Health Nurse being assigned to a school (p=0.025). These findings can be used to help guide school-based immunization programs for optimal uptake of the HPV vaccine among the student population. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Xylanase supplementation of a wheat-based diet improved nutrient digestion and mRNA expression of intestinal nutrient transporters in broiler chickens infected with Clostridium perfringens.

    PubMed

    Guo, Shuangshuang; Liu, Dan; Zhao, Xu; Li, Changwu; Guo, Yuming

    2014-01-01

    of wheat-based diets improved FCR and AME in birds irrespective of C. perfringens infection and elevated apparent ileal digestibility of CP and mRNA expression of nutrient transporters in challenged birds.

  18. Use of plant residues for improving soil fertility, pod nutrients, root growth and pod weight of okra (Abelmoschus esculentum L).

    PubMed

    Moyin-Jesu, Emmanuel Ibukunoluwa

    2007-08-01

    The effect of wood ash, sawdust, ground cocoa husk, spent grain and rice bran upon root development, ash content, pod yield and nutrient status and soil fertility for okra (Abelmoschus esculentum L NHAe 47 variety) was studied. The five organic fertilizer treatments were compared to chemical fertilizer (400kg/ha/crop NPK 15-15-15) and unfertilized controls in four field experiments replicated four times in a randomized complete block design. The results showed that the application of 6tha(-1) of plant residues increased (P<0.05) the soil N, P, K, Ca, Mg, pH, and SOM; pod N, P, K, Ca, Mg and ash; root length; and pod yield of okra in all four experiments relative to the control treatment. For instance, spent grain treatment increased the okra pod yield by 99%, 33%, 50%, 49%, 65% and 67% compared to control, NPK, wood ash, cocoa husk, rice bran and sawdust treatments respectively. In the stepwise regression, out of the total R(2) value of 0.83 for the soil nutrients to the pod yield of okra; soil N accounted for 50% of the soil fertility improvement and yield of okra. Spent grain, wood ash and cocoa husk were the most effective in improving okra pod weight, pod nutrients, ash content, root length and soil fertility whereas the rice bran and sawdust were the least effective. This was because the spent grain, wood ash and cocoa husk had lower C/N ratio and higher nutrient composition than rice bran and sawdust, thus, the former enhanced an increase in pod nutrients, composition for better human dietary intake, increased the root length, pod weight of okra and improved soil fertility and plant nutrition crop. The significance of the increases in okra mineral nutrition concentration by plant residues is that consumers will consume more of these minerals in their meals and monetarily spend less for purchasing vitamins and mineral supplement drugs to meet health requirements. In addition, the increase in plant nutrition and soil fertility would help to reduce the high cost

  19. Improved mucoadhesion and cell uptake of chitosan and chitosan oligosaccharide surface-modified polymer nanoparticles for mucosal delivery of proteins.

    PubMed

    Dyawanapelly, Sathish; Koli, Uday; Dharamdasani, Vimisha; Jain, Ratnesh; Dandekar, Prajakta

    2016-08-01

    The main aim of the present study was to compare mucoadhesion and cellular uptake efficiency of chitosan (CS) and chitosan oligosaccharide (COS) surface-modified polymer nanoparticles (NPs) for mucosal delivery of proteins. We have developed poly (D, L-lactide-co-glycolide) (PLGA) NPs, surface-modified COS-PLGA NPs and CS-PLGA NPs, by using double emulsion solvent evaporation method, for encapsulating bovine serum albumin (BSA) as a model protein. Surface modification of NPs was confirmed using physicochemical characterization methods such as particle size and zeta potential, SEM, TEM and FTIR analysis. Both surface-modified PLGA NPs displayed a slow release of protein compared to PLGA NPs. Furthermore, we have explored the mucoadhesive property of COS as a material for modifying the surface of polymeric NPs. During in vitro mucoadhesion test, positively charged COS-PLGA NPs and CS-PLGA NPs exhibited enhanced mucoadhesion, compared to negatively charged PLGA NPs. This interaction was anticipated to improve the cell interaction and uptake of NPs, which is an important requirement for mucosal delivery of proteins. All nanoformulations were found to be safe for cellular delivery when evaluated in A549 cells. Moreover, intracellular uptake behaviour of FITC-BSA loaded NPs was extensively investigated by confocal laser scanning microscopy and flow cytometry. As we hypothesized, positively charged COS-PLGA NPs and CS-PLGA NPs displayed enhanced intracellular uptake compared to negatively charged PLGA NPs. Our results demonstrated that CS- and COS-modified polymer NPs could be promising carriers for proteins, drugs and nucleic acids via nasal, oral, buccal, ocular and vaginal mucosal routes.

  20. Does counselling improve uptake of long-term and permanent contraceptive methods in a high HIV-prevalence setting?

    PubMed Central

    Dudley, Lilian; Makumucha, Courage; Dlamini, Phatisizwe; Moyo, Sihle; Bhembe, Sibongiseni

    2015-01-01

    Abstract Background Studies have shown a reduced uptake of contraceptive methods in HIV-positive women of childbearing age, mainly because of unmet needs that may be a result of poor promotion of available methods of contraception, especially long-term and permanent methods (LTPM). Aim To compare the uptake of contraceptive methods, and particularly LTPM, by HIV-positive and HIV-negative post-partum mothers, and to assess the effects of counselling on contraceptive choices. Setting Three government district hospitals in Swaziland. Methods Interviews were conducted using a structured questionnaire, before and after counselling HIV-negative and HIV-positive post-partum women in LTPM use, unintended pregnancy rates, future fertility and reasons for contraceptive choices. Results A total of 711 women, of whom half were HIV-positive, participated in the study. Most (72.3% HIV-negative and 84% HIV-positive) were on modern methods of contraception, with the majority using 2-monthly and 3-monthly injectables. Intended use of any contraceptive increased to 99% after counselling. LTPM use was 7.0% in HIV-negative mothers and 15.3% in HIV-positive mothers before counselling, compared with 41.3% and 42.4% in HIV-negative and HIV-positive mothers, respectively, after counselling. Pregnancy intentions and counselling on future fertility were significantly associated with current use of contraception, whilst current LTPM use and level of education were significantly associated with LTPM post-counselling. Conclusion Counselling on all methods including LTPM reduced unmet needs in contraception in HIV-positive and HIV-negative mothers and could improve contraceptive uptake and reduce unintended pregnancies. Health workers do not always remember to include LTPM when they counsel clients, which could result in a low uptake of these methods. Further experimental studies should be conducted to validate these results. PMID:26842525

  1. Improving uptake of screening for colorectal cancer: a study on invitation strategies and different test kit use

    PubMed Central

    Kojalo, Ilona; Huttunen, Teppo; Rikacovs, Sergejs; Rucevskis, Peteris; Boka, Viesturs; Leja, Marcis

    2015-01-01

    Objective The aim of this study was to compare the uptake of mail-delivered tests for colorectal cancer screening. We assessed the effect of an advance notification letter and a reminder letter, and analysed the proportion of inappropriately handled tests. Materials and methods Fifteen thousand randomly selected residents of Latvia aged 50–74 years were allocated to receive one of three different test systems: either a guaiac faecal occult blood test (gFOBT) or one of two laboratory-based immunochemical tests (FIT) – FOB Gold or OC-Sensor. Half of the target population received an advance notification letter; all nonresponders were sent a reminder letter. Results The uptake of screening was 31.2% for the gFOBT, 44.7% for FOB Gold and 47.4% for the OC-Sensor (odds ratio 0.55; 95% confidence interval 0.51–0.60 for gFOBT vs. FOB Gold; odds ratio 0.90; 95% confidence interval 0.83–0.98 for FOB Gold vs. OC-Sensor). The uptake in the gFOBT group was improved by the advance notification letter (7.7%, P<0.0001). 30.9% returned tests were received after the reminder letter. The proportion of tests that could not be analysed because of inadequate handling was 0.9% for gFOBT, 4.4% for FOB Gold and 0.2% for the OC-Sensor (P=0.002 for gFOBT vs. OC-Sensor; P<0.001 for all comparisons vs. FOB Gold). Conclusion The use of FIT resulted in higher uptake. Receipt of a reminder letter was critical to participation, but the use of an advance notification letter was important mainly for gFOBT. The proportion of inappropriately handled tests was markedly higher for FOB Gold. PMID:25806603

  2. Spatial Differentiation of Arable Land and Permanent Grasslands to Improve a Regional Land Management Model for Nutrient Balancing

    NASA Astrophysics Data System (ADS)

    Gómez Giménez, M.; Della Peruta, R.; de Jong, R.; Keller, A.; Schaepman, M. E.

    2015-12-01

    Agroecosystems play an important role providing economic and ecosystem services, which directly impact society. Inappropriate land use and unsustainable agricultural management with associated nutrient cycles can jeopardize important soil functions such as food production, livestock feeding and conservation of biodiversity. The objective of this study was to integrate remotely sensed land cover information into a regional Land Management Model (LMM) to improve the assessment of spatial explicit nutrient balances for agroecosystems. Remotely sensed data as well as an optimized parameter set contributed to feed the LMM providing a better spatial allocation of agricultural data aggregated at farm level. The integration of land use information in the land allocation process relied predominantly on three factors: i) spatial resolution, ii) classification accuracy and iii) parcels definition. The best-input parameter combination resulted in two different land cover classifications with overall accuracies of 98%, improving the LMM performance by 16% as compared to using non-spatially explicit input. Firstly, the use of spatial explicit information improved the spatial allocation output resulting in a pattern that better followed parcel boundaries (Figure 1). Second, the high classification accuracies ensured consistency between the datasets used. Third, the use of a suitable spatial unit to define the parcels boundaries influenced the model in terms of computational time and the amount of farmland allocated. We conclude that the combined use of remote sensing (RS) data with the LMM has the potential to provide highly accurate information of spatial explicit nutrient balances that are crucial for policy options concerning sustainable management of agricultural soils. Figure 1. Details of the spatial pattern obtained: a) Using only the farm census data, b) using also land use information. Framed in black in the left image (a), examples of artifacts that disappeared when

  3. Improving access to CPD for nurses: the uptake of online provision.

    PubMed

    Ousey, Karen; Roberts, Debbie

    2013-02-01

    Qualified nurses want to access courses that develop their knowledge and skills base within specific areas that are relevant to the work that they do. Traditional methods of delivery for post registration education usually involve attendance at a university or continuing professional development department for lectures and seminars. It is well known that barriers exist which prevent staff from being released to attend such educational activities, or to fund nurses education and development directly. Furthermore, education of the nursing workforce presents a dilemma for many education providers due to the range of learning styles of the current pool of potential students together with the ever changing demographics of the workforce. This paper aims to explore the dilemma faced by education providers and makes suggestions regarding possible solutions to supporting the continuing professional development of the nursing work force. In particular, education providers are encouraged to consider developing non-traditional study packages which maximise uptake through mechanisms such as on-line provision.

  4. Carbon Monoxide Fumigation Improved the Quality, Nutrients, and Antioxidant Activities of Postharvest Peach

    PubMed Central

    Li, Ying; Pei, Fei

    2014-01-01

    Peaches (Prunus persica cv. Yanhong) were fumigated with carbon monoxide (CO) at 0, 0.5, 5, 10, and 20 μmol/L for 2 hours. The result showed that low concentration CO (0.5–10 μmol/L) might delay the decrease of firmness and titrable acid content, restrain the increase of decay incidence, and postpone the variation of soluble solids content, but treating peaches with high concentration CO (20 μmol/L) demonstrated adverse effects. Further research exhibited that exogenous CO could induce the phenylalnine ammonialyase activity, maintain nutrient contents such as Vitamin C, total flavonoid, and polyphenol, and enhance antioxidant activity according to reducing power and 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl radical scavenging activity. Treating peaches with appropriate concentration CO was beneficial to the quality, nutrients, and antioxidant activity of postharvest peaches during storage time. Therefore, CO fumigation might probably become a novel method to preserve postharvest peach and other fruits in the future. PMID:26904651

  5. Facilitating Mitochondrial Calcium Uptake Improves Activation-Induced Cerebral Blood Flow and Behavior after mTBI

    PubMed Central

    Murugan, Madhuvika; Santhakumar, Vijayalakshmi; Kannurpatti, Sridhar S.

    2016-01-01

    Mild to moderate traumatic brain injury (mTBI) leads to secondary neuronal loss via excitotoxic mechanisms, including mitochondrial Ca2+ overload. However, in the surviving cellular population, mitochondrial Ca2+ influx, and oxidative metabolism are diminished leading to suboptimal neuronal circuit activity and poor prognosis. Hence we tested the impact of boosting neuronal electrical activity and oxidative metabolism by facilitating mitochondrial Ca2+ uptake in a rat model of mTBI. In developing rats (P25-P26) sustaining an mTBI, we demonstrate post-traumatic changes in cerebral blood flow (CBF) in the sensorimotor cortex in response to whisker stimulation compared to sham using functional Laser Doppler Imaging (fLDI) at adulthood (P67-P73). Compared to sham, whisker stimulation-evoked positive CBF responses decreased while negative CBF responses increased in the mTBI animals. The spatiotemporal CBF changes representing underlying neuronal activity suggested profound changes to neurovascular activity after mTBI. Behavioral assessment of the same cohort of animals prior to fLDI showed that mTBI resulted in persistent contralateral sensorimotor behavioral deficit along with ipsilateral neuronal loss compared to sham. Treating mTBI rats with Kaempferol, a dietary flavonol compound that enhanced mitochondrial Ca2+ uptake, eliminated the inter-hemispheric asymmetry in the whisker stimulation-induced positive CBF responses and the ipsilateral negative CBF responses otherwise observed in the untreated and vehicle-treated mTBI animals in adulthood. Kaempferol also improved somatosensory behavioral measures compared to untreated and vehicle treated mTBI animals without augmenting post-injury neuronal loss. The results indicate that reduced mitochondrial Ca2+ uptake in the surviving populations affect post-traumatic neural activation leading to persistent behavioral deficits. Improvement in sensorimotor behavior and spatiotemporal neurovascular activity following kaempferol

  6. Quercetin-Loaded Solid Lipid Nanoparticle Dispersion with Improved Physicochemical Properties and Cellular Uptake.

    PubMed

    Vijayakumar, Ajay; Baskaran, Rengarajan; Jang, Young Soo; Oh, Seung Hyun; Yoo, Bong Kyu

    2017-04-01

    The objective of this study was to formulate and characterize properties of solid lipid nanoparticle (SLN) dispersion containing quercetin. SLN was prepared by ultrasonication method using tripalmitin and lecithin as lipid core and then the surface was coated with chitosan. Entrapment efficiency was greater than 99%, and mean particle size of SLN was 110.7 ± 1.97 nm with significant increase in the coated SLN (c-SLN). Zeta potential was proportionally increased and reached plateau at 5% of chitosan coating with respect to tripalmitin. Differential scanning calorimetry showed disappearance of endothermic peak of quercetin in SLNs, indicating conversion of crystalline state to amorphous state. FTIR study of SLNs showed no change in the spectrum of quercetin, which indicates that the lipid and chitosan were not incompatible with quercetin. When coating amount was greater than 2.5% of tripalmitin, particle size and zeta potential were very stable even at 40°C up to 90 days. All SLN dispersions showed significantly faster release profile compared to pure quercetin powder. At pH 7.0, the release rate was increased in proportion to the coating amount. Interestingly, at pH 3.0, chitosan coating of 5.0% or greater decreased the rate. Cellular uptake of quercetin was performed using Caco-2 cells and showed that all SLN dispersions were significantly better than quercetin dispersed in distilled water. However, cellular uptake of quercetin from c-SLN was significantly lower than that from uncoated SLN.

  7. Enhancing soil infiltration reduces gaseous emissions and improves N uptake from applied dairy slurry.

    PubMed

    Bhandral, R; Bittman, S; Kowalenko, G; Buckley, K; Chantigny, M H; Hunt, D E; Bounaix, F; Friesen, A

    2009-01-01

    Rapid infiltration of liquid manure into the soil reduces emissions of ammonia (NH(3)) into the atmosphere. This study was undertaken to assess the effects of two low-cost methods of assisting infiltration of applied dairy slurry on emissions of NH(3), nitrous oxide (N(2)O), and on crop N uptake. The two methods were removing of solids by settling-decantation to make the manure less viscous and mechanically aerating the soil. Ammonia emissions were measured with wind tunnels as percentage of applied total ammoniacal nitrogen (TAN) while emissions of N(2)O were measured with vented chambers. Mechanically aerating the soil before manure application significantly reduced emissions of NH(3) relative to the nonaerated soil in spring (38.6 to 20.3% of applied TAN), summer (41.1 to 26.4% of applied TAN) and fall (27.7 to 13.6% of applied TAN) trials. Decantation of manure had no effect on NH(3) emissions in spring, tended to increase emissions in summer and significantly decreased emissions in fall (30.3 to 11.1% of applied TAN). Combining the two abatement techniques reduced NH(3) emission by 82% in fall, under cool weather conditions typical of manure spreading. The two abatement techniques generally did not significantly affect N(2)O emissions. Uptake of applied N by Italian ryegrass (Lolium multiflorum Lam.) was generally significantly greater with decanted than from whole manure but the effect of aeration was generally small and not significant. The study shows that low cost methods that assist manure infiltration into the soil may be used to greatly reduce ammonia loss without increasing N(2)O emissions, but efficacy of abatement methods is affected by weather conditions.

  8. Cacao liquor procyanidin extract improves glucose tolerance by enhancing GLUT4 translocation and glucose uptake in skeletal muscle.

    PubMed

    Yamashita, Yoko; Okabe, Masaaki; Natsume, Midori; Ashida, Hitoshi

    2012-01-01

    Hyperglycaemia and insulin resistance are associated with the increased risk of the metabolic syndrome and other severe health problems. The insulin-sensitive GLUT4 regulates glucose homoeostasis in skeletal muscle and adipose tissue. In this study, we investigated whether cacao liquor procyanidin (CLPr) extract, which contains epicatechin, catechin and other procyanidins, improves glucose tolerance by promoting GLUT4 translocation and enhances glucose uptake in muscle cells. Our results demonstrated that CLPr increased glucose uptake in a dose-dependent manner and promoted GLUT4 translocation to the plasma membrane of L6 myotubes. Oral administration of a single dose of CLPr suppressed the hyperglycaemic response after carbohydrate ingestion, which was accompanied by enhanced GLUT4 translocation in ICR mice. These effects of CLPr were independent of α-glucosidase inhibition in the small intestine. CLPr also promoted GLUT4 translocation in skeletal muscle of C57BL/6 mice fed a CLPr-supplemented diet for 7 d. These results indicate that CLPr is a beneficial food material for improvement of glucose tolerance by promoting GLUT4 translocation to the plasma membrane of skeletal muscle.

  9. Combined Application of Biofertilizers and Inorganic Nutrients Improves Sweet Potato Yields.

    PubMed

    Mukhongo, Ruth W; Tumuhairwe, John B; Ebanyat, Peter; AbdelGadir, AbdelAziz H; Thuita, Moses; Masso, Cargele

    2017-01-01

    Sweet potato [Ipomoea batatas (L) Lam] yields currently stand at 4.5 t ha(-1) on smallholder farms in Uganda, despite the attainable yield (45-48 t ha(-1)) of NASPOT 11 cultivar comparable to the potential yield (45 t ha(-1)) in sub-Saharan Africa (SSA). On-farm field experiments were conducted for two seasons in the Mt Elgon High Farmlands and Lake Victoria Crescent agro-ecological zones in Uganda to determine the potential of biofertilizers, specifically arbuscular mycorrhizal fungi (AMF), to increase sweet potato yields (NASPOT 11 cultivar). Two kinds of biofertilizers were compared to different rates of phosphorus (P) fertilizer when applied with or without nitrogen (N) and potassium (K). The sweet potato response to treatments was variable across sites (soil types) and seasons, and significant tuber yield increase (p < 0.05) was promoted by biofertilizer and NPK treatments during the short-rain season in the Ferralsol. Tuber yields ranged from 12.8 to 20.1 t ha(-1) in the Rhodic Nitisol (sandy-clay) compared to 7.6 to 14.9 t ha(-1) in the Ferralsol (sandy-loam) during the same season. Root colonization was greater in the short-rain season compared to the long-rain season. Biofertilizers combined with N and K realized higher biomass and tuber yield than biofertilizers alone during the short-rain season indicating the need for starter nutrients for hyphal growth and root colonization of AMF. In this study, N0.25PK (34.6 t ha(-1)) and N0.5PK (32.9 t ha(-1)) resulted in the highest yield during the long and the short-rain season, respectively, but there was still a yield gap of 11.9 and 13.6 t ha(-1) for the cultivar. Therefore, a combination of 90 kg N ha(-1) and 100 kg K ha(-1) with either 15 or 30 kg P ha(-1) can increase sweet potato yield from 4.5 to >30 t ha(-1). The results also show that to realize significance of AMF in nutrient depleted soils, starter nutrients should be included.

  10. Combined Application of Biofertilizers and Inorganic Nutrients Improves Sweet Potato Yields

    PubMed Central

    Mukhongo, Ruth W.; Tumuhairwe, John B.; Ebanyat, Peter; AbdelGadir, AbdelAziz H.; Thuita, Moses; Masso, Cargele

    2017-01-01

    Sweet potato [Ipomoea batatas (L) Lam] yields currently stand at 4.5 t ha−1 on smallholder farms in Uganda, despite the attainable yield (45–48 t ha−1) of NASPOT 11 cultivar comparable to the potential yield (45 t ha−1) in sub-Saharan Africa (SSA). On-farm field experiments were conducted for two seasons in the Mt Elgon High Farmlands and Lake Victoria Crescent agro-ecological zones in Uganda to determine the potential of biofertilizers, specifically arbuscular mycorrhizal fungi (AMF), to increase sweet potato yields (NASPOT 11 cultivar). Two kinds of biofertilizers were compared to different rates of phosphorus (P) fertilizer when applied with or without nitrogen (N) and potassium (K). The sweet potato response to treatments was variable across sites (soil types) and seasons, and significant tuber yield increase (p < 0.05) was promoted by biofertilizer and NPK treatments during the short-rain season in the Ferralsol. Tuber yields ranged from 12.8 to 20.1 t ha−1 in the Rhodic Nitisol (sandy-clay) compared to 7.6 to 14.9 t ha−1 in the Ferralsol (sandy-loam) during the same season. Root colonization was greater in the short-rain season compared to the long-rain season. Biofertilizers combined with N and K realized higher biomass and tuber yield than biofertilizers alone during the short-rain season indicating the need for starter nutrients for hyphal growth and root colonization of AMF. In this study, N0.25PK (34.6 t ha−1) and N0.5PK (32.9 t ha−1) resulted in the highest yield during the long and the short-rain season, respectively, but there was still a yield gap of 11.9 and 13.6 t ha−1 for the cultivar. Therefore, a combination of 90 kg N ha−1 and 100 kg K ha−1 with either 15 or 30 kg P ha−1 can increase sweet potato yield from 4.5 to >30 t ha−1. The results also show that to realize significance of AMF in nutrient depleted soils, starter nutrients should be included. PMID:28348569

  11. Multi-nutrient supplement improves hormone ratio associated with cancer risk

    PubMed Central

    2013-01-01

    Background Gynecological cancers are among the most common in women and are directly related to a variety of hormonal factors. One potential risk factor associated with developing a gynecological malignancy is the ratio of two hormone metabolites, 2-Hydroxyestrone (2-HE) and 16alpha-Hydroxyestrone (16alpha-HE). A number of botanical constituents such as indoles, flavonoids, and resveratrol have been shown to have a favorable effect on the metabolic pathways that affect this ratio. The present study was designed to evaluate if a multi-nutrient supplement containing targeted botanical constituents would affect the 2-HE/16 alpha-HE ratio in middle-aged women. Methods A retrospective analysis was performed on 76 female patients (mean age 54 years) who received 2-HE/16 alpha-HE ratio assessments at two separate time points. The ratio assessment was part of standard care for women who presented with risk indicators associated with a high proliferative state. All patients who completed pre and post assessments were included. Sixty-five of the patients received a multi-nutrient supplement, Lucentia Peak®, during the study period. Eleven patients chose not to take the supplement, but did receive ratio assessments at similar time points as the treatment group, allowing for between group comparisons. Paired t-tests were used to compare the changes in the 2-HE and 16alpha-HE measures as well as their ratio, both within groups and between groups. Results The results demonstrated a significant increase in the 2-HE/16alpha-HE ratio in the treated group (pre 0.38 to post 0.57, p<0.0001), and was significantly different (p=0.02) compared to the change in the control group (pre 0.65 to post 0.64). This change appears to be mediated primarily by an increase in the 2-HE level. Individually, 54 patients given Lucentia Peak® had increased ratios while 11 patients had a decrease. In the control group, 3 patients had an increase in their ratio and 8 patients had a decrease. Conclusions

  12. Does journal club membership improve research evidence uptake in different allied health disciplines: a pre-post study

    PubMed Central

    2012-01-01

    Background Although allied health is considered to be one 'unit' of healthcare providers, it comprises a range of disciplines which have different training and ways of thinking, and different tasks and methods of patient care. Very few empirical studies on evidence-based practice (EBP) have directly compared allied health professionals. The objective of this study was to examine the impact of a structured model of journal club (JC), known as iCAHE (International Centre for Allied Health Evidence) JC, on the EBP knowledge, skills and behaviour of the different allied health disciplines. Methods A pilot, pre-post study design using maximum variation sampling was undertaken. Recruitment was conducted in groups and practitioners such as physiotherapists, occupational therapists, speech pathologists, social workers, psychologists, nutritionists/dieticians and podiatrists were invited to participate. All participating groups received the iCAHE JC for six months. Quantitative data using the Adapted Fresno Test (McCluskey & Bishop) and Evidence-based Practice Questionnaire (Upton & Upton) were collected prior to the implementation of the JC, with follow-up measurements six months later. Mean percentage change and confidence intervals were calculated to compare baseline and post JC scores for all outcome measures. Results The results of this study demonstrate variability in EBP outcomes across disciplines after receiving the iCAHE JC. Only physiotherapists showed statistically significant improvements in all outcomes; speech pathologists and occupational therapists demonstrated a statistically significant increase in knowledge but not for attitude and evidence uptake; social workers and dieticians/nutritionists showed statistically significant positive changes in their knowledge, and evidence uptake but not for attitude. Conclusions There is evidence to suggest that a JC such as the iCAHE model is an effective method for improving the EBP knowledge and skills of allied

  13. Statistical innovations improve prevalence estimates of nutrient risk populations: applications in São Paulo, Brazil.

    PubMed

    Morimoto, Juliana Masami; Marchioni, Dirce Maria Lobo; Cesar, Chester Luiz Galvão; Fisberg, Regina Mara

    2012-10-01

    The objective of this study was to estimate the prevalence of inadequate micronutrient intake and excess sodium intake among adults age 19 years and older in the city of São Paulo, Brazil. Twenty-four-hour dietary recall and sociodemographic data were collected from each participant (n=1,663) in a cross-sectional study, Inquiry of Health of São Paulo, of a representative sample of the adult population of the city of São Paulo in 2003 (ISA-2003). The variability in intake was measured through two replications of the 24-hour recall in a subsample of this population in 2007 (ISA-2007). Usual intake was estimated by the PC-SIDE program (version 1.0, 2003, Department of Statistics, Iowa State University), which uses an approach developed by Iowa State University. The prevalence of nutrient inadequacy was calculated using the Estimated Average Requirement cut-point method for vitamins A and C, thiamin, riboflavin, niacin, copper, phosphorus, and selenium. For vitamin D, pantothenic acid, manganese, and sodium, the proportion of individuals with usual intake equal to or more than the Adequate Intake value was calculated. The percentage of individuals with intake equal to more than the Tolerable Upper Intake Level was calculated for sodium. The highest prevalence of inadequacy for males and females, respectively, occurred for vitamin A (67% and 58%), vitamin C (52% and 62%), thiamin (41% and 50%), and riboflavin (29% and 19%). The adjustment for the within-person variation presented lower prevalence of inadequacy due to removal of within-person variability. All adult residents of São Paulo had excess sodium intake, and the rates of nutrient inadequacy were high for certain key micronutrients.

  14. Improving macroscopic modeling of the effect of water and osmotic stresses on root water uptake.

    NASA Astrophysics Data System (ADS)

    Jorda Guerra, Helena; Vanderborght, Jan

    2015-04-01

    Accurate modeling of water and salt stresses on root water uptake is critical for predicting impacts of global change and climate variability on crop production and soil water balances. Soil-hydrological models use reduction functions to represent the effect of osmotic stress in transpiration. However, these functions, which were developed empirically, present limitations in relation to the time and spatial scale at which they need to be used, fail to include compensation processes and do not agree on how water and salt stresses interact. This research intends to develop a macroscopic reduction function for water and osmotic stresses based on biophysical knowledge. Simulation experiments are conducted for a range of atmospheric conditions, soil and plant properties, irrigation water quality and scheduling using a 3-D physically-based model that resolves flow and transport to individual root segments and that couples flow in the soil and root system (Schröder et al., 2013). The effect of salt concentrations on water flow in the soil-root system is accounted for by including osmotic water potential gradients between the solution at the soil root interface and the root xylem sap in the hydraulic gradient between the soil and root. In a first step, simulation experiments are carried out in a soil volume around a single root segment. We discuss how the simulation setup can be defined so as to represent: (i) certain characteristics of the root system such as rooting depth and root length density, (ii) plant transpiration rate, (iii) leaching fraction of the irrigation, and (iii) salinity of the irrigation water. The output of these simulation experiments gives a first insight in the effect of salinity on transpiration and on the relation between the bulk salinity in the soil voxel, which is used in macroscopic salt stress functions of models that do not resolve processes at the root segment scale, and the salinity at the soil-root interface, which determines the actual

  15. Irrigation of three wetland species and a hyperaccumlating fern with arsenic-laden solutions: observations of growth, arsenic uptake, nutrient status, and chlorophyll content.

    PubMed

    Rofkar, Jordan R; Dwyer, Daryl F

    2013-01-01

    Engineered wetlands can be an integral part of a treatment strategy for remediating arsenic-contaminated wastewater, wherein, As is removed by adsorption to soil particles, chemical transformation, precipitation, or accumulation by plants. The remediation process could be optimized by choosing plant species that take up As throughout the seasonal growing period. This report details experiments that utilize wetland plant species native to Ohio (Carex stricta, Pycnanthemum virginianum, and Spartina pectinata) that exhibit seasonally related maximal growth rates, plus one hyperaccumulating fern (Pteris vittata) that was used to compare arsenic tolerance. All plants were irrigated with control or As-laden nutrient solutions (either 0, 1.5, or 25 mg As L(-1)) for 52 d. Biomass, nutrient content, and chlorophyll content were compared between plants treated and control plants (n = 5). At the higher concentration of arsenic (25 mg L(-1)), plant biomass, leaf area, and total chlorophyll were all lower than values in control plants. A tolerance index, based on total plant biomass at the end of the experiment, indicated C. stricta (0.99) and S. pectinata (0.84) were more tolerant than the other plant species when irrigated with 1.5 mg As L(-1). These plant species can be considered as candidates for engineered wetlands.

  16. Cardiac resynchronization therapy improves the uptake of MIBI-99mTc and cardiac function.

    PubMed

    Brandão, Simone Cristina Soares; Giorgi, Maria Clementina; Nishioka, Silvana D'Orio; Martinelli Filho, Martino; Soares, José; Meneghetti, José Cláudio

    2008-09-01

    This case shows the improvement promoted by cardiac resynchronization therapy (CRT) on myocardial perfusion and left ventricular (LV) performance assessed by gated myocardial perfusion scintigraphy. The patient had idiopathic dilated cardiomyopathy, left bundle branch block and severe heart failure despite optimized medical treatment. After CRT, clinical improvement, QRS reduction and improvement of previously hypoperfused anterior and septal walls were observed. There was also decrease in LV end-diastolic and systolic volumes and increase in LV ejection fraction.

  17. Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture.

    PubMed

    Voogt, Wim; Holwerda, Harmen T; Khodabaks, Rashied

    2010-04-15

    Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 microg iodine L(-1), applied as iodate (IO(3)(-)) or iodide (I(-)), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I(-) than with IO(3)(-). Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 microg iodine kg(-1) total leaf fresh weight. Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I(-) and IO(3)(-). I(-) was more effective than IO(3)(-). Fifty grams of iodine-biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. (c) 2010 Society of Chemical Industry.

  18. Improving the culturability of freshwater bacteria using FW70, a low-nutrient solid medium amended with sodium pyruvate.

    PubMed

    Imazaki, Iori; Kobori, Youichi

    2010-04-01

    Bacterial culture based on the use of plate media is an effective method for investigating bacterial populations in the environment. To improve the culturability of bacteria from freshwater lakes, we developed a new medium, FW70, which contains sodium pyruvate, casamino acids, and lake water and is solidified using gellan gum. To test the importance of these components, we prepared a series of media in which one or more of the components was absent. Water was sampled 31 times from 3 Japanese lakes and was passed through a membrane filter (pore size = 0.45 microm) to remove fast-growing microbes before the water was spread onto the plates. In most cases, significantly larger numbers of bacterial colonies were detected on FW70 than on other media. Furthermore, to test the practicality of FW70, we compared it with standard nutrient agar and R2A agar. In all cases, the culturability was significantly greater on FW70 than on standard nutrient agar or R2A agar. Some isolates recovered by means of FW70 belonged to bacteria that had not previously been classified. These results suggest that FW70 improves the culturability of freshwater bacteria and can be used for the isolation of novel bacteria as a result of the filtration step.

  19. Alternating Magnetic Field Controlled, Multifunctional Nano-Reservoirs: Intracellular Uptake and Improved Biocompatibility

    NASA Astrophysics Data System (ADS)

    Ghosh, Santaneel; Ghoshmitra, Somesree; Cai, Tong; Diercks, David R.; Mills, Nathaniel C.; Hynds, Dianna L.

    2010-01-01

    Biocompatible magnetic nanoparticles hold great therapeutic potential, but conventional particles can be toxic. Here, we report the synthesis and alternating magnetic field dependent actuation of a remotely controllable, multifunctional nano-scale system and its marked biocompatibility with mammalian cells. Monodisperse, magnetic nanospheres based on thermo-sensitive polymer network poly(ethylene glycol) ethyl ether methacrylate- co-poly(ethylene glycol) methyl ether methacrylate were synthesized using free radical polymerization. Synthesized nanospheres have oscillating magnetic field induced thermo-reversible behavior; exhibiting desirable characteristics comparable to the widely used poly- N-isopropylacrylamide-based systems in shrinkage plus a broader volumetric transition range. Remote heating and model drug release were characterized for different field strengths. Nanospheres containing nanoparticles up to an iron concentration of 6 mM were readily taken up by neuron-like PC12 pheochromocytoma cells and had reduced toxicity compared to other surface modified magnetic nanocarriers. Furthermore, nanosphere exposure did not inhibit the extension of cellular processes (neurite outgrowth) even at high iron concentrations (6 mM), indicating minimal negative effects in cellular systems. Excellent intracellular uptake and enhanced biocompatibility coupled with the lack of deleterious effects on neurite outgrowth and prior Food and Drug Administration (FDA) approval of PEG-based carriers suggest increased therapeutic potential of this system for manipulating axon regeneration following nervous system injury.

  20. Polyacetylenes from carrots (Daucus carota) improve glucose uptake in vitro in adipocytes and myotubes.

    PubMed

    El-Houri, Rime B; Kotowska, Dorota; Christensen, Kathrine B; Bhattacharya, Sumangala; Oksbjerg, Niels; Wolber, Gerhard; Kristiansen, Karsten; Christensen, Lars P

    2015-07-01

    A dichloromethane (DCM) extract of carrot roots was found to stimulate insulin-dependent glucose uptake (GU) in adipocytes in a dose dependent manner. Bioassay-guided fractionation of the DCM extract resulted in the isolation of the polyacetylenes falcarinol and falcarindiol. Both polyacetylenes were able to significantly stimulate basal and/or insulin-dependent GU in 3T3-L1 adipocytes and porcine myotube cell cultures in a dose-dependent manner. Falcarindiol increased peroxisome proliferator-activated receptor (PPAR)γ-mediated transactivation significantly at concentrations of 3, 10 and 30 μM, while PPARγ-mediated transactivation by falcarinol was only observed at 10 μM. Docking studies accordingly indicated that falcarindiol binds to the ligand binding domain of PPARγ with higher affinity than falcarinol and that both polyacetylenes exhibit characteristics of PPARγ partial agonists. Falcarinol was shown to inhibit adipocyte differentiation as evident by gene expression studies and Oil Red O staining, whereas falcarindiol did not inhibit adipocyte differentiation, which indicates that these polyacetylenes have distinct modes of action. The results of the present study suggest that falcarinol and falcarindiol may represent scaffolds for novel partial PPARγ agonists with possible antidiabetic properties.

  1. Improved oxygen uptake efficiency slope in acute myocardial infarction patients after early phase I cardiac rehabilitation.

    PubMed

    Tsai, Yun-Jeng; Li, Min-Hui; Chen, Chia-Hsin; Tuan, Sheng-Hui; Chen, Yi-Jen; Lin, Ko-Long

    2017-09-01

    A predischarge submaximal exercise test is often recommended after acute myocardial infarction (AMI) as part of phase I cardiac rehabilitation. In this study, a submaximal exercise parameter, oxygen uptake efficiency slope (OUES), was used to monitor the benefit of early mobilization within 48 h after AMI. An early mobilization protocol within 48 h after AMI has been initiated since 1 September 2012 in our center. Patients with onset time of AMI within 1 year before and 1 year after initiation of the early mobilization protocol were recruited for comparisons. Sixty patients were analyzed on the basis of this criterion, and were subjected to predischarge submaximal exercise tests. The OUES calculated with 100% exercise duration (OUES100) and calculated with the first 50% of exercise duration (OUES50) were obtained and analyzed. Both OUES100 and OUES50 of the AMI patients with early mobilization were significantly higher than those without early mobilization (P=0.025 and 0.007, respectively). The OUES100 and OUES50 were also highly correlated (r=0.891, P<0.001). The subgroup analysis using patients within 3 months before and 3 months after initiation of the protocol also showed a significant difference. OUES could be used to measure the exercise capacity and monitor the effect of phase I cardiac rehabilitation in patients soon after AMI. Early mobilization within 48 h following AMI significantly enhanced the patient's exercise capacity.

  2. Improvements in modeling of pulmonary uptake of toxicants. Final report for period ending August 1994

    SciTech Connect

    Collins, R.

    1994-11-01

    The primary objective of this technical report is to provide a rational foundation for quantitatively evaluating the importance of unsteady versus steady or quasi-steady events during uptake of chemical toxicants via the human respiratory tract. A secondary objective is to review critically the current approaches in physiologically-based pharmacokinetic (PBPK) modeling of the lung with a view to generalizing the model descriptions to encompass a broader range of exposure and physiological conditions. The secondary objective is addressed frist, with a succinct review of the transport mechanisms that con operate within the respiratory tract when exposed to a concentration of chemical toxicants in the form of vapors, aerosols, and particulate matter. Functional relationships are reviewed within the context of a voluminous body of international literature bearing on this and related subjects of importance. Computational models are proposed to provide an essential complementary research tool with not only simulative but also predictive capabilities. Drawing upon this considerable background of established knowledge, one can proceed more readily with a detailed study of the very important question posed as the primary objective; namely, the establishment of an order-of- magnitude analysis resulting in a general classification scheme that identifies three major flow regimes, distinguished on the basis of whether the flow is dominated by unsteadiness, viscous effects, or the effects of convective acceleration. The report concludes with some important recommendations regarding the extrapolation of test results performed on small laboratory animals to the human context.

  3. H2O2 pretreated rice seedlings specifically reduces arsenate not arsenite: difference in nutrient uptake and antioxidant defense response in a contrasting pair of rice cultivars.

    PubMed

    Mallick, Shekhar; Kumar, Navin; Sinha, Sarita; Dubey, Arvind Kumar; Tripathi, Rudra Deo; Srivastav, Vivek

    2014-10-01

    The study investigated the reduction in metalloid uptake at equimolar concentrations (~53.3 μM) of As(III) and As(V) in contrasting pair of rice seedlings by pretreating with H2O2 (1.0 μM) and SA (1.0 mM). Results obtained from the contrasting pair (arsenic tolerant vs. sensitive) of rice seedlings (cv. Pant Dhan 11 and MTU 7029, respectively) shows that pretreatment of H2O2 and H2O2 + SA reduces As(V) uptake significantly in both the cultivars, while no reduction in the As(III) uptake. The higher growth inhibition, higher H2O2 and TBARS content in sensitive cultivar against As(III) and As(V) treatments along with higher As accumulation (~1.2 mg g(-1) dw) than in cv. P11, unravels the fundamental difference in the response between the sensitive and tolerant cultivar. In the H2O2 pretreated plants, the translocation of As increased in tolerant cultivar against AsIII, whereas, it decreased in sensitive cultivar both against AsIII and AsV. In both the cultivars translocation of Mn increased in the H2O2 pretreated plants against As(III), whereas, the translocation of Cu increased against As(V). In tolerant cultivar the translocation of Fe increased against As(V) with H2O2 pretreatment whereas, it decreased in the sensitive cultivar. In both the cultivars, Zn translocation increased against As(III) and decreased against As(V). The higher level of H2O2 and SOD (EC 1.15.1.1) activity in sensitive cultivar whereas, higher, APX (EC 1.11.1.11), GR (EC 1.6.4.2) and GST (EC 1.6.4.2) activity in tolerant cultivar, also demonstrated the differential anti-oxidative defence responses between the contrasting rice cultivars.

  4. Nutrient Influences on Leaf Photosynthesis

    PubMed Central

    Longstreth, David J.; Nobel, Park S.

    1980-01-01

    The net rate of CO2 uptake for leaves of Gossypium hirsutum L. was reduced when the plants were grown at low concentrations of NO3-, PO42-, or K+. The water vapor conductance was relatively constant for all nutrient levels, indicating little effect on stomatal response. Although leaves under nutrient stress tended to be lower in chlorophyll and thinner, the ratio of mesophyll surface area to leaf area did not change appreciably. Thus, the reduction in CO2 uptake rate at low nutrient levels was due to a decrease in the CO2 conductance expressed per unit mesophyll cell wall area (gcellCO2). The use of gcellCO2 and nutrient levels expressed per unit of mesophyll cell wall provides a new means of assessing nutrient effects on CO2 uptake of leaves. PMID:16661231

  5. Nutrient sources in a Mediterranean catchment and their improvement for water quality management

    NASA Astrophysics Data System (ADS)

    Candela, Angela; Viviani, Gaspare

    2010-05-01

    Changes in land-use or management strategies may affect water outflow, sediment and nutrients loads. Thus, there is an increasing demand for quantitative information at the catchment scale that would help decision makers or planners to take appropriate decisions. The characterisation of water status, the description of pollution sources impact, the establishment of monitoring programs and the implementation of river basin management plans require an analysis of the current basin status and estimates of the relative significance of the different sources of pollution. Particularly, in this study the Soil and Water Assessment Tool (SWAT2000) model was considered since it is an integrated hydrological model that simulates both the qualitative as well as quantitative terms of hydrological balances. It is a spatially distributed hydrological model that operates on a daily time step at catchment scale developed by the Agricultural Research Service at the U.S. Department of Agriculture. Its purpose is to simulate water sediment and chemical yields on large river basins and possible impacts of land use, climate changes and watershed management. Integrated hydrological models are, nowadays, needed to support the implementation of integrated water management plans and to comply with the current requirements of the European Water Directive. Actually, they can help in evaluating current water resources, identify pollution sources, evaluate alternative management policies. More specifically, the analysis has been applied to the Oreto catchment (77 Km2), an agricultural and urbanised catchment located in Sicily (Italy). Residential, commercial, farm and industrial settlements cover almost the entire area. The climate is Mediterranean with hot dry summer and rainy winter season. The hydrological response of this basin is dominated by long dry seasons and following wetting-up periods, during which even large inputs of rainfall may produce little or no response at the basin outlet

  6. Preexposure prophylaxis-related stigma: strategies to improve uptake and adherence - a narrative review.

    PubMed

    Haire, Bridget G

    2015-01-01

    Des