Science.gov

Sample records for plant availability improvement

  1. Improved outage management techniques for better plant availability

    SciTech Connect

    Bemer, J.P.

    1989-01-01

    To maintain high availability of nuclear generating units is one of the most important management objectives. The duration of outages-whether planned or unplanned-is the main parameter impacting on plant availability, but the planned outages, and essentially the refueling outages, are the most important in this respect, and they also have a heavy impact on the economics of plant operation. The following factors influence the duration of the outages: (1) modifications; (2) preventive maintenance operations; and (3) corrective maintenance operations of generic faults. In this paper, the authors examine how the outage management organization of Electricite de France (EdF) plants is tending to optimize the solutions to the above-mentioned points.

  2. Nitric Oxide Improves Internal Iron Availability in Plants1

    PubMed Central

    Graziano, Magdalena; Beligni, María Verónica; Lamattina, Lorenzo

    2002-01-01

    Iron deficiency impairs chlorophyll biosynthesis and chloroplast development. In leaves, most of the iron must cross several biological membranes to reach the chloroplast. The components involved in the complex internal iron transport are largely unknown. Nitric oxide (NO), a bioactive free radical, can react with transition metals to form metal-nitrosyl complexes. Sodium nitroprusside, an NO donor, completely prevented leaf interveinal chlorosis in maize (Zea mays) plants growing with an iron concentration as low as 10 μm Fe-EDTA in the nutrient solution. S-Nitroso-N-acetylpenicillamine, another NO donor, as well as gaseous NO supply in a translucent chamber were also able to revert the iron deficiency symptoms. A specific NO scavenger, 2-(4-carboxy-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, blocked the effect of the NO donors. The effect of NO treatment on the photosynthetic apparatus of iron-deficient plants was also studied. Electron micrographs of mesophyll cells from iron-deficient maize plants revealed plastids with few photosynthetic lamellae and rudimentary grana. In contrast, in NO-treated maize plants, mesophyll chloroplast appeared completely developed. NO treatment did not increase iron content in plant organs, when expressed in a fresh matter basis, suggesting that root iron uptake was not enhanced. NO scavengers 2-(4-carboxy-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and methylene blue promoted interveinal chlorosis in iron-replete maize plants (growing in 250 μm Fe-EDTA). Even though results support a role for endogenous NO in iron nutrition, experiments did not establish an essential role. NO was also able to revert the chlorotic phenotype of the iron-inefficient maize mutants yellow stripe1 and yellow stripe3, both impaired in the iron uptake mechanisms. All together, these results support a biological action of NO on the availability and/or delivery of metabolically active iron within the plant. PMID:12481068

  3. Guide for prioritizing power plant productivity improvement projects: handbook of availability improvement methodology

    SciTech Connect

    Not Available

    1981-09-15

    As part of its program to help improve electrical power plant productivity, the Department of Energy (DOE) has developed a methodology for evaluating productivity improvement projects. This handbook presents a simplified version of this methodology called the Availability Improvement Methodology (AIM), which provides a systematic approach for prioritizing plant improvement projects. Also included in this handbook is a description of data taking requirements necessary to support the AIM methodology, benefit/cost analysis, and root cause analysis for tracing persistent power plant problems. In applying the AIM methodology, utility engineers should be mindful that replacement power costs are frequently greater for forced outages than for planned outages. Equivalent availability includes both. A cost-effective ranking of alternative plant improvement projects must discern between those projects which will reduce forced outages and those which might reduce planned outages. As is the case with any analytical procedure, engineering judgement must be exercised with respect to results of purely mathematical calculations.

  4. Feasibility studies to improve plant availability and reduce total installed cost in IGCC plants

    SciTech Connect

    Sullivan, Kevin; Anasti, William; Fang, Yichuan; Subramanyan, Karthik; Leininger, Tom; Zemsky, Christine

    2015-03-30

    The main purpose of this project is to look at technologies and philosophies that would help reduce the costs of an Integrated Gasification Combined Cycle (IGCC) plant, increase its availability or do both. GE’s approach to this problem is to consider options in three different areas: 1) technology evaluations and development; 2) constructability approaches; and 3) design and operation methodologies. Five separate tasks were identified that fall under the three areas: Task 2 – Integrated Operations Philosophy; Task 3 – Slip Forming of IGCC Components; Task 4 – Modularization of IGCC Components; Task 5 – Fouling Removal; and Task 6 – Improved Slag Handling. Overall, this project produced results on many fronts. Some of the ideas could be utilized immediately by those seeking to build an IGCC plant in the near future. These include the considerations from the Integrated Operations Philosophy task and the different construction techniques of Slip Forming and Modularization (especially if the proposed site is in a remote location or has a lack of a skilled workforce). Other results include ideas for promising technologies that require further development and testing to realize their full potential and be available for commercial operation. In both areas GE considers this project to be a success in identifying areas outside the core IGCC plant systems that are ripe for cost reduction and ity improvement opportunities.

  5. Geocomposite with Superabsorbent as an Element Improving Water Availability for Plants on Slopes

    NASA Astrophysics Data System (ADS)

    Pawlowski, A.; Lejcus, K.; Garlikowski, D.; Orzeszyna, H.

    2009-04-01

    Water availability for plants on a slope is usually worse, then on a plane surface. Exposure on sun radiation makes these conditions even more difficult. The key problem is how to supply plants with water. Frequently watering is good but expensive solution. To avoid often repeating of such action and/or to use as much as possible water from precipitation, it has to be retained in soil. One of the ways to increase soil water retention is superabsorbents (SAP), called often hydrogel addition to the soil. They can absorb 300 - 1000 times more water, then theirs own weight. This water can be later taken by roots system. Addition to the soil small amount of dry superabsorbent, which, after absorbing water, forms gel can affect stability of the slope top layer, diminishing soil strength parameters. Part of the strength lose can be recompensed by reinforcing action of better developed roots system, which, according to the tests are increasing soil shear strength. However because it is a living system still rest some uncertainty about its functioning over many vegetation seasons. From engineering point of view, these strength parameters are very difficult for precise calculation, control and determination of long term behaviour. Important factor of superabsorbent influence on soil shear parameters is its dosage and, as a result, final volume and properties after water absorption. If the volume of superabsorbent is not greater then available pore volume of soil, this influence is not decisive. By bigger dosage, when volume of superabsorbent with retained water is much greater then pore space volume. The soil form a suspension in hydrogel and in laboratory condition one can observe sedimentation of soil fraction at the early stage of saturation. After longer time gel's density is already high enough to support grains of soils and stop sedimentation process. By highly permeable soils, which are sometimes used in embankment construction, eg. for buttress, gel, just after

  6. Decreasing water availability across the globe improves the effectiveness of protective ant-plant mutualisms: a meta-analysis.

    PubMed

    Leal, Laura C; Peixoto, Paulo E C

    2016-10-28

    Abiotic conditions can increase the costs of services and/or the benefits of rewards provided by mutualistic partners. Consequently, in some situations, the outcome of mutualisms can move from beneficial to detrimental for at least one partner. In the case of protective mutualisms between ant bodyguards and plants bearing extrafloral nectaries (EFNs), plants from arid environments face a trade-off between EFN production and maintenance and water and carbon economy. This trade-off may increase EFN costs and decrease their value as a defensive strategy to plants in such environments. Despite this, the presence of EFNs is an ubiquitous trait in plants from arid environments, suggesting that they provide greater benefits to plants in these environments to compensate for their higher costs. We used a meta-analysis to investigate if such benefits do increase with decreasing water availability and the possible underlying causes (such as ant behaviour or ant diversity). As predicted, ant effect on EFN plants performance increased as mean annual precipitation decreased. We also found that the frequency of dominant ants on EFN plants increased in drier areas. Due to the more aggressive behaviour of dominant ants, we suggest that they represent an important factor shaping the adaptive value of EFNs to plants in arid environments.

  7. Genomic DNA extraction from medicinal plants available in Malaysia using a TriOmic(TM) improved extraction kit.

    PubMed

    Mohd-Hairul, A R; Sade, A B; Yiap, B C; Raha, A R

    2011-11-08

    DNA extraction was carried out on 32 medicinal plant samples available in Malaysia using the TriOmic(TM) extraction kit. Amounts of 0.1 g flowers or young leaves were ground with liquid nitrogen, lysed at 65°C in RY1(plus) buffer and followed by RNAse treatment. Then, RY2 buffer was added to the samples and mixed completely by vortexing before removal of cell debris by centrifugation. Supernatants were transferred to fresh microcentrifuge tubes and 0.1 volume RY3 buffer was added to each of the transferred supernatant. The mixtures were applied to spin columns followed by a centrifugation step to remove buffers and other residues. Washing step was carried out twice by applying 70% ethanol to the spin columns. Genomic DNA of the samples was recovered by applying 50 μL TE buffer to the membrane of each spin column, followed by a centrifugation step at room temperature. A modification of the TriOmic(TM) extraction procedure was carried out by adding chloroform:isoamyl alcohol (24:1) steps in the extraction procedure. The genomic DNA extracted from most of the 32 samples showed an increase of total yield when chloroform:isoamyl alcohol (24:1) steps were applied in the TriOmicTM extraction procedure. This preliminary study is very important for molecular studies of medicinal plants available in Malaysia since the DNA extraction can be completed in a shorter period of time (within 1 h) compared to manual extraction, which entails applying phenol, chloroform and ethanol precipitation, and requires 1-2 days to complete.

  8. International Atomic Energy Agency specialists meeting on experience in ageing, maintenance, and modernization of instrumentation and control systems for improving nuclear power plant availability

    SciTech Connect

    Not Available

    1993-10-01

    This report presents the proceedings of the Specialist`s Meeting on Experience in Aging, Maintenance and Modernization of Instrumentation and Control Systems for Improving Nuclear Power Plant Availability that was held at the Ramada Inn in Rockville, Maryland on May 5--7, 1993. The Meeting was presented in cooperation with the Electric Power Research Institute, Oak Ridge National Laboratory and the International Atomic Energy Agency. There were approximately 65 participants from 13 countries at the Meeting. Individual reports have been cataloged separately.

  9. Methodology for Scaling Fusion Power Plant Availability

    SciTech Connect

    Lester M. Waganer

    2011-01-04

    Normally in the U.S. fusion power plant conceptual design studies, the development of the plant availability and the plant capital and operating costs makes the implicit assumption that the plant is a 10th of a kind fusion power plant. This is in keeping with the DOE guidelines published in the 1970s, the PNL report1, "Fusion Reactor Design Studies - Standard Accounts for Cost Estimates. This assumption specifically defines the level of the industry and technology maturity and eliminates the need to define the necessary research and development efforts and costs to construct a one of a kind or the first of a kind power plant. It also assumes all the "teething" problems have been solved and the plant can operate in the manner intended. The plant availability analysis assumes all maintenance actions have been refined and optimized by the operation of the prior nine or so plants. The actions are defined to be as quick and efficient as possible. This study will present a methodology to enable estimation of the availability of the one of a kind (one OAK) plant or first of a kind (1st OAK) plant. To clarify, one of the OAK facilities might be the pilot plant or the demo plant that is prototypical of the next generation power plant, but it is not a full-scale fusion power plant with all fully validated "mature" subsystems. The first OAK facility is truly the first commercial plant of a common design that represents the next generation plant design. However, its subsystems, maintenance equipment and procedures will continue to be refined to achieve the goals for the 10th OAK power plant.

  10. Characterisation of European varieties of triticale with special emphasis on the ability of plant phytase to improve phytate phosphorus availability to chickens.

    PubMed

    Jondreville, C; Genthon, C; Bouguennec, A; Carre, B; Nys, Y

    2007-12-01

    1. A total of 30 varieties and selection lines of triticale grown under similar conditions were characterised. Thousand grain weight, specific weight, Hagberg falling number and N were 50.2 +/- 5.0 g, 72.4 +/- 2.1 kg/hl, 96 +/- 48 s and 16.1 +/- 0.11 g/kg, respectively. 2. Mean phosphorus (P) concentration was 2.86 +/- 0.31 g/kg, of which 77% was of phytic origin. Mean phytase activity was 1018 +/- 319 phytase units (PU)/kg. A genotypic effect on phytase activity was detected amongst 5 varieties studied out of 30. Potential and real applied viscosities were positively correlated and mean values were 3.53 +/- 0.66 and 2.15 +/- 0.31 ml/g, respectively. 3. The efficacy of plant phytase in improving P availability was assessed in chickens up to 3 weeks of age. Growth performance and bone ash concentration were compared in birds given either a maize (450 g/kg) and soybean meal (230 g/kg) phosphorus deficient diet containing 3.5 g P/kg, this basal diet supplemented with 1 or 2 g P/kg as monocalcium phosphate (MCP) or triticale (450 g/kg) and soybean meal (230 g/kg) diets containing 3.2 to 3.8 g P/kg with no MCP. To achieve graded levels of phytase activity, 4 varieties of triticale, intact or in which phytase was denaturated by heat treatment, were used. Estimated metabolisable energy, protein, amino acids and calcium concentrations were similar in all diets. 4. Phytase activity in the triticale-based diets ranged between 135 and 1390 PU/kg. Growth performance and bone ash were responsive to plant phytase and to MCP. Non-linear models of these responses were adjusted with the best fit for bone ash parameters. The values of 250, 500 and 1000 PU of plant phytase were estimated to be equivalent to 0.46, 0.67 and 0.81 g P as MCP, respectively.

  11. Role of ethylene in responses of plants to nitrogen availability

    PubMed Central

    Khan, M. I. R.; Trivellini, Alice; Fatma, Mehar; Masood, Asim; Francini, Alessandra; Iqbal, Noushina; Ferrante, Antonio; Khan, Nafees A.

    2015-01-01

    Ethylene is a plant hormone involved in several physiological processes and regulates the plant development during the whole life. Stressful conditions usually activate ethylene biosynthesis and signaling in plants. The availability of nutrients, shortage or excess, influences plant metabolism and ethylene plays an important role in plant adaptation under suboptimal conditions. Among the plant nutrients, the nitrogen (N) is one the most important mineral element required for plant growth and development. The availability of N significantly influences plant metabolism, including ethylene biology. The interaction between ethylene and N affects several physiological processes such as leaf gas exchanges, roots architecture, leaf, fruits, and flowers development. Low plant N use efficiency (NUE) leads to N loss and N deprivation, which affect ethylene biosynthesis and tissues sensitivity, inducing cell damage and ultimately lysis. Plants may respond differently to N availability balancing ethylene production through its signaling network. This review discusses the recent advances in the interaction between N availability and ethylene at whole plant and different organ levels, and explores how N availability induces ethylene biology and plant responses. Exogenously applied ethylene seems to cope the stress conditions and improves plant physiological performance. This can be explained considering the expression of ethylene biosynthesis and signaling genes under different N availability. A greater understanding of the regulation of N by means of ethylene modulation may help to increase NUE and directly influence crop productivity under conditions of limited N availability, leading to positive effects on the environment. Moreover, efforts should be focused on the effect of N deficiency or excess in fruit trees, where ethylene can have detrimental effects especially during postharvest. PMID:26579172

  12. Lotus japonicus plants of the Gifu B-129 ecotype subjected to alkaline stress improve their Fe(2+) bio-availability through inoculation with Pantoea eucalypti M91.

    PubMed

    Campestre, María Paula; Castagno, Luis Nazareno; Estrella, María Julia; Ruiz, Oscar Adolfo

    2016-03-15

    Inoculation assays with Pantoea eucalypti M91 were performed on Lotus japonicus ecotype Gifu. Under alkaline conditions, this ecotype is characterized by the development of interveinal chlorosis of the apical leaves due to low mobilization of Fe(2+). Inoculation with P. eucalypti M91, a plant growth-promoting bacterial strain capable of producing pyoverdine-like and pyochelin-like siderophores under alkaline growth conditions, alters the root, resulting in a herringbone pattern of root branching. Additional features include improvement in Fe(2+) transport to the shoots, acidification of the hydroponic solution of the plant cultures, and an accompanying increase in the efficiency of the PSII parameters. In addition, there was an increase in the expression of the FRO1 and IRT1 genes, accompanied by a significant increase in FRO activity. Results showed that P. eucalypti M91 has a beneficial effect on the Fe acquisition machinery of Strategy I, as described for non-graminaceous monocots and dicots, suggesting its potential as an inoculant for legume crops cultivated in alkaline soils. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Plant Available Nutrients, Barrow, Alaska, Ver. 1

    DOE Data Explorer

    Sloan, Victoria; Liebig, Jenny; Curtis, Bryan; Hahn, Melanie; Iversen, Colleen; Siegrist, Julie

    2014-02-19

    This dataset consists of measurements of plant available nutrients made using Plant Root Simulator probes (Western Ag Innovations Inc.) during 2012 and 2013. In 2012, Ca, Mg, K, P, Fe, Mn, Cu, Zn, B, S, Pb, Al, Cd, NO3-N and NH4-N were measured during spring, summer and winter in the centers, edges and troughs of four polygons in each of four areas of contrasting moisture regime and polygon type. In 2013, probes were installed in centers, edges and troughs of four polygons in each of two areas (high-centered and low-centered polygons) at two-week intervals and at 3 soil depths to capture fine-scale season dynamics of NO3-N and NH4-N. PRS probes are ion exchange resin membranes held in plastic supports that are inserted into soil to measure ion supply in situ. The anion and cation exchange with the membrane is intended to mimic plant uptake and thus provide a relevant measure of soil nutrient bioavailability. Measurements are made per area of probe membrane and cannot be converted to concentrations or related to soil volume.

  14. Antidiabetic plants improving insulin sensitivity.

    PubMed

    Eddouks, Mohamed; Bidi, Amina; El Bouhali, Bachir; Hajji, Lhoussain; Zeggwagh, Naoufel Ali

    2014-09-01

    Globally, the prevalence of diabetes mellitus is increasing at an alarming rate. This chronic pathology gravely troubled the human health and quality of life. Both insulin deficiency and insulin resistance are involved in the pathophysiology of diabetes mellitus. Moreover, insulin resistance is being diagnosed nowadays in a growing population of diabetic and obese patients, especially in industrialized societies. There are lots of conventional agents available to control and to treat diabetes, but total recovery from this disorder has not been reported up to this date. Plants provided a potential source of hypoglycemic drugs and are widely used in several traditional systems of medicine to prevent diabetes. A few reviews with less attention paid to mechanisms of action have been published on antidiabetic plants. The present review focuses on the various plants that have been reported to be effective in improving insulin sensitivity associated with diabetes. In this work, an updated systematic review of the published literature has been conducted to review the antidiabetic plants improving insulin sensitivity and 111 medicinal plants have been reported to have a beneficial effect on insulin sensitivity using several in-vitro and in-vivo animal models of diabetes. The different metabolic and cellular effects of the antidiabetic plants improving insulin sensitivity are reported indicating the important role of medicinal plants as potential alternative or complementary use in controlling insulin resistance associated with diabetes mellitus. © 2014 Royal Pharmaceutical Society.

  15. Regional Availability of Plants for Prairie Restoration

    DTIC Science & Technology

    2007-04-01

    limited on Corps land, a ERDC TN-EMRRP-SI-31 April 2007 6 recent study (Cully et al. 2003) indicated that small fragments of tallgrass prairie ...replicated a 110-acre prairie planted with an array of grasses and wildflowers to show visitors how the prairie in this area appeared historically. Despite...its limited size, a variety of native grasses and prairie wildflowers provide year-round color and give visitors a glimpse at the beauty the prairie

  16. More physicians: improved availability or induced demand?

    PubMed

    Carlsen, F; Grytten, J

    1998-09-01

    A number of empirical studies have shown that there is a negative association between population:physician ratio and utilization of medical services. However, it is not clear whether this relationship reflects supplier-inducement, the effect of lower prices on patient demand, a supply response to variation in health status, or improved availability. In Norway, patient fees and state reimbursement fees are set centrally. Therefore, the correlation between utilization and population:physician ratio either reflects supplier-inducement, a supply response or an availability effect. We applied a theoretical model which distinguished between an inducement and an availability effect. The model was implemented on a cross-sectional data set which contained information about patient visits and laboratory tests for all fee-for-service primary care physicians in Norway. Since population:physician ratio is potentially endogenous, an instrumental variable approach is used. We found no evidence for inducement either for number of visits or for provision of laboratory services.

  17. Availability of herbal medicines and medicinal plants in the primary health facilities of the state of São Paulo, Southeast Brazil: results from the National Program for Access and Quality Improvement in Primary Care.

    PubMed

    Caccia-Bava, Maria do Carmo Gullaci Guimarães; Bertoni, Bianca Waléria; Pereira, Ana Maria Soares; Martinez, Edson Zangiacomi

    2017-05-01

    This study aims to describe the availability of herbal medicines and medicinal plants in the primary care facilities in the state of São Paulo, Southeast Brazil, from the results of the first cycle of the National Program for Access and Quality Improvement in Primary Care (PMAQ). The PMAQ uses a national cross-sectional multicenter design, with data from 4,249 health facilities distributed among 645 municipalities of the state of São Paulo. Of these facilities, 467 (11%) had herbal medicines and/or medicinal plants. Among the 645 municipalities, 104 (16.1%) had at least one health facility that provided these drugs. We observed that the availability of herbal medicines is greater in larger cities with better social and economic conditions. Furthermore, we found that use of industrialized herbal medicines prevailed over that of vegetal drugs or compounded herbal medicines.

  18. Synergy between pathogen release and resource availability in plant invasion

    PubMed Central

    Blumenthal, Dana; Mitchell, Charles E.; Pyšek, Petr; Jarošík, Vojtěch

    2009-01-01

    Why do some exotic plant species become invasive? Two common hypotheses, increased resource availability and enemy release, may more effectively explain invasion if they favor the same species, and therefore act in concert. This would be expected if plant species adapted to high levels of available resources in their native range are particularly susceptible to enemies, and therefore benefit most from a paucity of enemies in their new range. We tested this possibility by examining how resource adaptations influence pathogen richness and release among 243 European plant species naturalized in the United States. Plant species adapted to higher resource availability hosted more pathogen species in their native range. Plants from mesic environments hosted more fungi than plants from xeric environments, and plants from nitrogen-rich environments hosted more viruses than plants from nitrogen-poor environments. Furthermore, plants classified as competitors hosted more than 4 times as many fungi and viruses as did stress tolerators. Patterns of enemy release mirrored those of pathogen richness: competitors and species from mesic and nitrogen-rich environments were released from many pathogen species, while stress tolerators and species from xeric and nitrogen-poor environments were released from relatively few pathogen species. These results suggest that enemy release contributes most to invasion by fast-growing species adapted to resource-rich environments. Consequently, enemy release and increases in resource availability may act synergistically to favor exotic over native species. PMID:19416888

  19. Plant nutrient availability from mixtures of fly ashes and biosolids

    SciTech Connect

    Schumann, A.W.; Summer, M.E.

    1999-10-01

    Nutrient imbalances, both deficiencies and excesses, are one reason for the poor acceptance of waste materials as fertilizer substitutes. Two greenhouse experiments were established using 24 different fly ashes with sewage sludge and poultry manure to estimate nutrient availability and imbalances to maize (Zea mays L.). The maximum maize growth attained with fly ash amendment of 80 Mg ha{sup {minus}1} was significantly less (50%) than a fertilized control treatment. The additional growth improvements obtained from mixtures with sewage sludge or poultry manure ranged from 30 to 49% and 30 to 71%, respectively. Organic materials applied alone achieved only 54 and 62% of the maximum potential, while growth on poultry manure mixtures was up to 94% of the best performing fertilized treatment. Results of foliage and soil analyses suggest that P and K were the main nutrient deficiencies, while B phytotoxicity and an imbalance in the K/Ca/Mg ratio also were likely causes of plant growth reduction. Fly ashes did not contribute significant P or K to correct soil and plant deficiencies, but more often exacerbated the imbalances by precipitation or adsorption of soil P. Sewage sludge mixed at 26% and poultry manure at 13% (DM) with fly ash had negligible effect on availability of phytotoxic fly ash B, but were good sources of P (both) and K (poultry manure). Good agreement between plant nutrition in pot experiments and previous laboratory extraction studies implies that chemical analysis, efficient formulation and optimized application rates may overcome nutrient limitations for use of wastes as fertilizer substitutes.

  20. THEORETICAL AND EXPERIMENTAL ANALYSIS OF AVAILABILITY IN NUCLEAR POWER PLANTS.

    DTIC Science & Technology

    The method of generating functions is used to calculate the probability of successful operation of a nuclear power plant for given fractions of the...repair data obtained are used in the computing code for illustration. The outline of a proposed Nuclear Power Plant Availability Handbook is included to illustrate the topics which would be covered and their arrangement. (Author)

  1. Improved modeling of GPS selective availability

    NASA Technical Reports Server (NTRS)

    Braasch, Michael S.; Fink, Annmarie; Duffus, Keith

    1994-01-01

    Selective Availability (SA) represents the dominant error source for stand-alone users of the Global Positioning System (GPS). Even for DGPS, SA mandates the update rate required for a desired level of accuracy in realtime applications. As was witnessed in the recent literature, the ability to model this error source is crucial to the proper evaluation of GPS-based systems. A variety of SA models were proposed to date; however, each has its own shortcomings. Most of these models were based on limited data sets or data which were corrupted by additional error sources. A comprehensive treatment of the problem is presented. The phenomenon of SA is discussed and a technique is presented whereby both clock and orbit components of SA are identifiable. Extensive SA data sets collected from Block 2 satellites are presented. System Identification theory then is used to derive a robust model of SA from the data. This theory also allows for the statistical analysis of SA. The stationarity of SA over time and across different satellites is analyzed and its impact on the modeling problem is discussed.

  2. Topographic, edaphic, and vegetative controls on plant-available water

    USGS Publications Warehouse

    Dymond, Salli F.; Bradford, John B.; Bolstad, Paul V.; Kolka, Randall K.; Sebestyen, Stephen D.; DeSutter, Thomas S.

    2017-01-01

    Soil moisture varies within landscapes in response to vegetative, physiographic, and climatic drivers, which makes quantifying soil moisture over time and space difficult. Nevertheless, understanding soil moisture dynamics for different ecosystems is critical, as the amount of water in a soil determines a myriad ecosystem services and processes such as net primary productivity, runoff, microbial decomposition, and soil fertility. We investigated the patterns and variability in in situ soil moisture measurements converted to plant-available water across time and space under different vegetative cover types and topographic positions at the Marcell Experimental Forest (Minnesota, USA). From 0 – 228.6 cm soil depth, plant-available water was significantly higher under the hardwoods (12%), followed by the aspen (8%) and red pine (5%) cover types. Across the same soil depth, toeslopes were wetter (mean plant-available water = 10%) than ridges and backslopes (mean plant-available water was 8%), although these differences were not statistically significant (p < 0.05). Using a mixed model of fixed and random effects, we found that cover type, soil texture, and time were related to plant-available water and that topography was not significantly related to plant-available water within this low-relief landscape. Additionally, during the three-year monitoring period, red pine and quaking aspen sites experienced plant-available water levels that may be considered limiting to plant growth and function. Given that increasing temperatures and more erratic precipitation patterns associated with climate change may result in decreased soil moisture in this region, these species may be sensitive and vulnerable to future shifts in climate.

  3. Shifts in water availability mediate plant-pollinator interactions.

    PubMed

    Gallagher, M Kate; Campbell, Diane R

    2017-07-01

    Altered precipitation patterns associated with anthropogenic climate change are expected to have many effects on plants and insect pollinators, but it is unknown if effects on pollination are mediated by changes in water availability. We tested the hypothesis that impacts of climate on plant-pollinator interactions operate through changes in water availability, and specifically that such effects occur through alteration of floral attractants. We manipulated water availability in two naturally occurring Mertensia ciliata (Boraginaceae) populations using water addition, water reduction and control plots and measured effects on vegetative and floral traits, pollinator visitation and seed set. While most floral trait values, including corolla size and nectar, increased linearly with increasing water availability, in this bumblebee-pollinated species, pollinator visitation peaked at intermediate water levels. Visitation also peaked at an intermediate corolla length, while its relationship to corolla width varied across sites. Seed set, however, increased linearly with water. These results demonstrate the potential for changes in water availability to impact plant-pollinator interactions through pollinator responses to differences in floral attractants, and that the effects of water on pollinator visitation can be nonlinear. Plant responses to changes in resource availability may be an important mechanism by which climate change will affect species interactions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  4. Resource availability controls fungal diversity across a plant diversity gradient

    USGS Publications Warehouse

    Waldrop, M.P.; Zak, D.R.; Blackwood, C.B.; Curtis, C.D.; Tilman, D.

    2006-01-01

    Despite decades of research, the ecological determinants of microbial diversity remain poorly understood. Here, we test two alternative hypotheses concerning the factors regulating fungal diversity in soil. The first states that higher levels of plant detritus production increase the supply of limiting resources (i.e. organic substrates) thereby increasing fungal diversity. Alternatively, greater plant diversity increases the range of organic substrates entering soil, thereby increasing the number of niches to be filled by a greater array of heterotrophic fungi. These two hypotheses were simultaneously examined in experimental plant communities consisting of one to 16 species that have been maintained for a decade. We used ribosomal intergenic spacer analysis (RISA), in combination with cloning and sequencing, to quantify fungal community composition and diversity within the experimental plant communities. We used soil microbial biomass as a temporally integrated measure of resource supply. Plant diversity was unrelated to fungal diversity, but fungal diversity was a unimodal function of resource supply. Canonical correspondence analysis (CCA) indicated that plant diversity showed a relationship to fungal community composition, although the occurrence of RISA bands and operational taxonomic units (OTUs) did not differ among the treatments. The relationship between fungal diversity and resource availability parallels similar relationships reported for grasslands, tropical forests, coral reefs, and other biotic communities, strongly suggesting that the same underlying mechanisms determine the diversity of organisms at multiple scales. ?? 2006 Blackwell Publishing Ltd/CNRS.

  5. Linking phosphorus availability with photo-oxidative stress in plants.

    PubMed

    Hernández, Iker; Munné-Bosch, Sergi

    2015-05-01

    Plants have evolved a plethora of mechanisms to circumvent the potential damaging effects of living under low phosphorus availability in the soil. These mechanisms include different levels of organization, from root-shoot signalling at the whole-plant level to specific biochemical responses at the subcellular level, such as reductions in photosynthesis and the consequent activation of photo- and antioxidant mechanisms in chloroplasts. Some recent studies clearly indicate that severe phosphorus deficiency can lead to alterations in the photosynthetic apparatus, including reductions in CO2 assimilation rates, a down-regulation of photosynthesis-related genes and photoinhibition at the photosystem II level, thus causing potential photo-oxidative stress. Photo-oxidative stress is characterized by an increased production of reactive oxygen species in chloroplasts, which at low concentrations can serve a signalling, protective role, but when present at high concentrations can cause damage to lipids, proteins and nucleic acids, thus leading to irreversible injuries. We discuss here the mechanisms that phosphate-starved plants have evolved to withstand photo-oxidative stress, including changes at the subcellular level (e.g. activation of photo- and antioxidant protection mechanisms in chloroplasts), cellular and tissular levels (e.g. activation of photorespiration and anthocyanin accumulation) and whole-plant level (alterations in source-sink relationships modulated by hormones). Of particular importance is the current evidence demonstrating that phosphate-starved plants activate simultaneous responses at multiple levels, from transcriptional changes to root-shoot signalling, to prevent oxidative damage. In this review, we summarize current knowledge about the occurrence of photo-oxidative stress in phosphate-starved plants and highlight the mechanisms these plants have evolved to prevent oxidative damage under phosphorus limitation at the subcellular, cellular and whole-plant

  6. Compounds and methods for improving plant performance

    DOEpatents

    Unkefer, Pat J.; Knight, Thomas Joseph

    2016-09-20

    The invention is directed to methods and compositions for increasing a growth characteristic of a plant, increasing nutrient use efficiency of a plant, or improving a plant's ability to overcome stress comprising applying a composition comprising ketosuccinamate, a derivative thereof, or a salt thereof, to the plant or to a propagation material of the plant.

  7. Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity.

    PubMed

    Muller, Jonathon N; Loh, Susan; Braggion, Ligia; Cameron, Stephen; Firn, Jennifer L

    2014-01-01

    Buildings structures and surfaces are explicitly being used to grow plants, and these "urban plantings" are generally designed for aesthetic value. Urban plantings also have the potential to contribute significant "ecological values" by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban center of Brisbane, Australia (subtropical climatic region) over 2, 6 week sampling periods characterized by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation), plant CO2 assimilation, soil CO2 efflux, and arthropod diversity. Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly-likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context.

  8. Plant response to nutrient availability across variable bedrock geologies

    USGS Publications Warehouse

    Castle, S.C.; Neff, J.C.

    2009-01-01

    We investigated the role of rock-derived mineral nutrient availability on the nutrient dynamics of overlying forest communities (Populus tremuloides and Picea engelmanni-Abies lasiocarpa v. arizonica) across three parent materials (andesite, limestone, and sandstone) in the southern Rocky Mountains of Colorado. Broad geochemical differences were observed between bedrock materials; however, bulk soil chemistries were remarkably similar between the three different sites. In contrast, soil nutrient pools were considerably different, particularly for P, Ca, and Mg concentrations. Despite variations in nutrient stocks and nutrient availability in soils, we observed relatively inflexible foliar concentrations and foliar stoichiometries for both deciduous and coniferous species. Foliar nutrient resorption (P and K) in the deciduous species followed patterns of nutrient content across substrate types, with higher resorption corresponding to lower bedrock concentrations. Work presented here indicates a complex plant response to available soil nutrients, wherein plant nutrient use compensates for variations in supply gradients and results in the maintenance of a narrow range in foliar stoichiometry. ?? 2008 Springer Science+Business Media, LLC.

  9. Plant-microorganism-soil interactions influence the Fe availability in the rhizosphere of cucumber plants.

    PubMed

    Pii, Youry; Penn, Alexander; Terzano, Roberto; Crecchio, Carmine; Mimmo, Tanja; Cesco, Stefano

    2015-02-01

    Iron (Fe) is a very important element for plants, since it is involved in many biochemical processes and, often, for the low solubility of the natural Fe sources in soil, plants suffer from Fe - deficiency, especially when grown on calcareous soils. Among the numerous plant growth-promoting rhizobacteria (PGPR) that colonize the rhizosphere of agronomically important crops, Azospirillum brasilense has been shown to exert strong stimulating activities on plants, by inducing alterations of the root architecture and an improvement of mineral nutrition, which could result from an enhancement of ion uptake mechanisms as well as by increased bioavailability of nutrients. Some studies have also established that A. brasilense can act as biocontrol agent, by preventing the growth and/or virulence of phytopathogens, most likely through the production of microbial siderophores that sequester Fe from the soil. Despite microbial siderophores complexed with Fe could be an easily accessible Fe source for plants, the possible involvement of A. brasilense in improving Fe nutrition in plants suffering from the micronutrient deficiency has not been investigated yet. Within the present research, the characterization of the physiological and biochemical effects induced by Fe starvation and PGPR inoculation in cucumber plants (Cucumis sativus L. cv. Chinese Long) was carried out. The analyses of root exudates released by hydroponically grown plants highlighted that cucumber plants respond differently depending on the nutritional status. In addition, following the cultivation period on calcareous soil, also the root exudates found in the extracts suggested a peculiar behaviour of plants as a function of the treatment. Interestingly, the presence of the inoculum in soil allowed a faster recovery of cucumber plants from Fe-deficiency symptoms, i.e. increase in the chlorophyll content, in the biomass and in the Fe content of leaves. These observations might suggest a feasible application of

  10. Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity

    PubMed Central

    Muller, Jonathon N.; Loh, Susan; Braggion, Ligia; Cameron, Stephen; Firn, Jennifer L.

    2014-01-01

    Buildings structures and surfaces are explicitly being used to grow plants, and these “urban plantings” are generally designed for aesthetic value. Urban plantings also have the potential to contribute significant “ecological values” by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban center of Brisbane, Australia (subtropical climatic region) over 2, 6 week sampling periods characterized by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation), plant CO2 assimilation, soil CO2 efflux, and arthropod diversity. Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly—likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context. PMID:25400642

  11. Plant-Available Silica in Soils: A Mass Balance Approach

    NASA Astrophysics Data System (ADS)

    Reyerson, P. E.; Jacobs, P. M.; Mason, J. A.

    2009-12-01

    The goals of this study were to measure the quantity of high solubility soil silica available for plant uptake (plant-available silica, or PAS, operationally defined using a chemical extraction method); estimate gains and losses (mass balance) of PAS; and identify forms of PAS in soils. We used a coupled chemical extraction-spectrometry technique to measure PAS levels in soils. Gains and losses of PAS were achieved by comparing concentrations of an immobile element by horizon, in this case Zr. Forms of PAS were identified by light microscopy. Two Alfisol soils formed in thick loess were used for this study, one from southeastern Minnesota and the other from west-central Illinois. We identified two distinct origins for PAS: that which is inherited from the parent material, and that which is formed from in situ silicate mineral weathering. We further identified two general forms of PAS: biogenic (e.g. phytoliths) and nonbiogenic (e.g. dissolved silica, cristobalite). Measured, relative PAS levels were found to “spike” in B horizons of both soils, while A and C horizons were much lower. Absolute PAS levels differed between the two soils: The Minnesota soil yielded much higher levels throughout the profile than the Illinois soil, which we attributed to a large amount of inherited nonbiogenic PAS in the former soil. Mass balance data indicated loss of PAS in A horizons, probably due to leaching. A large positive flux of PAS was recorded in B horizons indicating downward movement of PAS and/or in situ weathering of silicate minerals. Forms of PAS vary by horizon as well, with different processes dominating over vertical space. Biologic processes were found to be dominant in A horizons, while chemical weathering and illuviation were dominant in B horizons.

  12. Precursor Report of Data Needs and Recommended Practices for PV Plant Availability Operations and Maintenance Reporting.

    SciTech Connect

    Hill, Roger R.; Klise, Geoffrey Taylor; Balfour, John R.

    2015-01-01

    Characterizing the factors that affect reliability of a photovoltaic (PV) power plant is an important aspect of optimal asset management. This document describes the many factors that affect operation and maintenance (O&M) of a PV plant, identifies the data necessary to quantify those factors, and describes how data might be used by O&M service providers and others in the PV industry. This document lays out data needs from perspectives of reliability, availability, and key performance indicators and is intended to be a precursor for standardizing terminology and data reporting, which will improve data sharing, analysis, and ultimately PV plant performance.

  13. Evaluation of plant biomass resources available for replacement of fossil oil

    PubMed Central

    Henry, Robert J

    2010-01-01

    The potential of plants to replace fossil oil was evaluated by considering the scale of production required, the area of land needed and the types of plants available. High yielding crops (50 tonnes/ha) that have a high conversion efficiency (75%) would require a global land footprint of around 100 million ha to replace current (2008) oil consumption. Lower yielding or less convertible plants would require a larger land footprint. Domestication of new species as dedicated energy crops may be necessary. A systematic analysis of higher plants and their current and potential uses is presented. Plant biotechnology provides tools to improve the prospects of replacing oil with plant-derived biomass by increasing the amount of biomass produced per unit area of land and improving the composition of the biomass to increase the efficiency of conversion to biofuel and biomaterials. Options for the production of high value coproducts and the expression of processing aids such as enzymes in the plant may add further value to plants as bioenergy resources. PMID:20070873

  14. Evaluation of plant biomass resources available for replacement of fossil oil.

    PubMed

    Henry, Robert J

    2010-04-01

    The potential of plants to replace fossil oil was evaluated by considering the scale of production required, the area of land needed and the types of plants available. High yielding crops (50 tonnes/ha) that have a high conversion efficiency (75%) would require a global land footprint of around 100 million ha to replace current (2008) oil consumption. Lower yielding or less convertible plants would require a larger land footprint. Domestication of new species as dedicated energy crops may be necessary. A systematic analysis of higher plants and their current and potential uses is presented. Plant biotechnology provides tools to improve the prospects of replacing oil with plant-derived biomass by increasing the amount of biomass produced per unit area of land and improving the composition of the biomass to increase the efficiency of conversion to biofuel and biomaterials. Options for the production of high value coproducts and the expression of processing aids such as enzymes in the plant may add further value to plants as bioenergy resources.

  15. Cost and availability of gadolinium for nuclear fuel reprocessing plants

    SciTech Connect

    Klepper, O.H.

    1985-06-01

    Gadolinium is currently planned for use as a soluble neutron poison in nuclear fuel reprocessing plants to prevent criticality of solutions of spent fuel. Gadolinium is relatively rare and expensive. The present study was undertaken therefore to estimate whether this material is likely to be available in quantities sufficient for fuel reprocessing and at reasonable prices. It was found that gadolinium, one of 16 rare earth elements, appears in the marketplace as a by-product and that its present supply is a function of the production rate of other more prevalent rare earths. The potential demand for gadolinium in a fuel reprocessing facility serving a future fast reactor industry amounts to only a small fraction of the supply. At the present rate of consumption, domestic supplies of rare earths containing gadolinium are adequate to meet national needs (including fuel reprocessing) for over 100 years. With access to foreign sources, US demands can be met well beyond the 21st century. It is concluded therefore that the supply of gadolinium will quite likely be more than adequate for reprocessing spent fuel for the early generation of fast reactors. The current price of 99.99% pure gadolinium oxide lies in the range $50/lb to $65/lb (1984 dollars). By the year 2020, in time for reprocessing spent fuel from an early generation of large fast reactors, the corresponding values are expected to lie in the $60/lb to $75/lb (1984 dollars) price range. This increase is modest and its economic impact on nuclear fuel reprocessing would be minor. The economic potential for recovering gadolinium from the wastes of nuclear fuel reprocessing plants (which use gadolinium neutron poison) was also investigated. The cost of recycled gadolinium was estimated at over twelve times the cost of fresh gadolinium, and thus recycle using current recovery technology is not economical. 15 refs., 4 figs., 11 tabs.

  16. PV System 'Availability' as a Reliability Metric -- Improving Standards, Contract Language and Performance Models

    SciTech Connect

    Klise, Geoffrey T.; Hill, Roger; Walker, Andy; Dobos, Aron; Freeman, Janine

    2016-11-21

    The use of the term 'availability' to describe a photovoltaic (PV) system and power plant has been fraught with confusion for many years. A term that is meant to describe equipment operational status is often omitted, misapplied or inaccurately combined with PV performance metrics due to attempts to measure performance and reliability through the lens of traditional power plant language. This paper discusses three areas where current research in standards, contract language and performance modeling is improving the way availability is used with regards to photovoltaic systems and power plants.

  17. Mobilization of interactions between functional diversity of plant and soil organisms on nitrogen availability and use

    NASA Astrophysics Data System (ADS)

    Drut, Baptiste; Cassagne, Nathalie; Cannavacciuolo, Mario; Brauman, Alain; Le Floch, Gaëtan; Cobo, Jose; Fustec, Joëlle

    2017-04-01

    Keywords: legumes, earthworms, microorganisms, nitrogen, interactions Both aboveground and belowground biodiversity and their interactions can play an important role in crop productivity. Plant functional diversity, such as legume based intercrops have been shown to improve yields through plant complementarity for nitrogen use (Corre-Hellou et al., 2006). Moreover, plant species or plant genotype may influence the structure of soil microorganism communities through the composition of rhizodeposits in the rhizosphere (Dennis et al., 2010). Belowground diversity can also positively influence plant performance especially related to functional dissimilarity between soil organisms (Eisenhauer, 2012). Earthworms through their burrowing activity influence soil microbial decomposers and nutrient availability and have thus been reported to increase plant growth (Brown, 1995; Brown et al., 2004). We hypothesize that i) plant functional (genetic and/or specific) diversity associated to functional earthworms diversity are key drivers of interactions balance to improve crop performances and ii) the improvement of plant performances can be related to change in the structure of soil microorganism communities due to the diversity of rhizodeposits and the burrowing activity of earthworms. In a first mesocosm experiment, we investigated the effect of a gradient of plant diversity - one cultivar of wheat (Triticum aestivum L.), 3 different wheat cultivars, and 3 different cultivars intercropped with clover (Trifolium hybridum L.) - and the presence of one (endogeic) or two (endogeic and anecic) categories of earthworms on biomass and nitrogen accumulation of wheat. In a second mesocosm experiment, we investigated the influence of three species with different rhizodeposition - wheat, rapeseed (Brassica napus L. ) and faba bean (Vicia faba L.) in pure stand or intercropped - and the presence of endogeic earthworms on microbial activity and nitrogen availability. In the first experiment

  18. Satellite monitoring of desert plant community response to moisture availability.

    PubMed

    Peters, A J; Eve, M D

    1995-01-01

    Our study demonstrates the utility of coarse spatial-resolution satellite spectra for analysis of vegetation phenophases and response to moisture availability in an arid ecosystem. We show the feasibility of deriving information on vegetation parameters such as stress and growth patterns in arid regions through the use of satellite-derived vegetation indices, despite the usual problems associated with a high ratio of soil to vegetation cover. Vegetation in our study area consists of Chihuahuan Desert grassland and scrub, including extensive zones of mixed desert scrub and grassland. Historic vegetation change has been well documented and is exemplified by decreasing grass cover and increasing shrub cover, a general trend of desertification. Our analysis suggests that satellite-based inputs can be used to improve our understanding of the spatial dynamics of climatic impacts on natural vegetation and to help us distinguish these processes from human-caused desertification.

  19. Estimating plant available water content from remotely sensed evapotranspiration

    NASA Astrophysics Data System (ADS)

    van Dijk, A. I. J. M.; Warren, G.; Doody, T.

    2012-04-01

    Plant available water content (PAWC) is an emergent soil property that is a critical variable in hydrological modelling. PAWC determines the active soil water storage and, in water-limited environments, is the main cause of different ecohydrological behaviour between (deep-rooted) perennial vegetation and (shallow-rooted) seasonal vegetation. Conventionally, PAWC is estimated for a combination of soil and vegetation from three variables: maximum rooting depth and the volumetric water content at field capacity and permanent wilting point, respectively. Without elaborate local field observation, large uncertainties in PAWC occur due to the assumptions associated with each of the three variables. We developed an alternative, observation-based method to estimate PAWC from precipitation observations and CSIRO MODIS Reflectance-based Evapotranspiration (CMRSET) estimates. Processing steps include (1) removing residual systematic bias in the CMRSET estimates, (2) making spatially appropriate assumptions about local water inputs and surface runoff losses, (3) using mean seasonal patterns in precipitation and CMRSET to estimate the seasonal pattern in soil water storage changes, (4) from these, calculating the mean seasonal storage range, which can be treated as an estimate of PAWC. We evaluate the resulting PAWC estimates against those determined in field experiments for 180 sites across Australia. We show that the method produces better estimates of PAWC than conventional techniques. In addition, the method provides detailed information with full continental coverage at moderate resolution (250 m) scale. The resulting maps can be used to identify likely groundwater dependent ecosystems and to derive PAWC distributions for each combination of soil and vegetation type.

  20. Improving antivenom availability and accessibility: science, technology, and beyond.

    PubMed

    Gutiérrez, José María

    2012-09-15

    Snakebite envenomings constitute a serious and neglected public health problem. Despite the fact that effective treatment exists, i.e. administration of animal-derived antivenoms, the availability and accessibility of these life-saving immunobiologicals is deficitary in various parts of the world, particularly in sub-Saharan Africa and some regions of Asia. This article discusses some of the problems that need to be circumvented in order to improve the availability and accessibility of antivenoms. The conglomerate of antivenom manufacturers is highly heterogeneous in terms of technological base, qualification of staff, implementation of Good Manufacturing Practices (GMPs), and volume of production. Therefore, improvements in antivenom quality and availability should be based on strategies tailored to the situation of each region or country; in this context, three different scenarios are discussed. Accessibility of antivenoms demands concerted efforts at multiple levels, including raising the awareness of public health authorities on the relevance of the problem, implementing innovative antivenom purchasing schemes, strengthening national distribution channels on the basis of robust epidemiological information, improving the cold chain and the provision of health services in remote rural settings, supporting the correct use of antivenoms, and promoting the involvement of local community organizations in various aspects of prevention and management. These tasks should be envisaged in terms of synergistic, interprogrammatic and intersectorial interventions, with the participation of many players.

  1. Measurement of plant-available zinc in British Columbia orchard soils

    SciTech Connect

    Neilsen, D.; Hoyt, P.B.; MacKenzie, A.F.

    1987-01-01

    Zinc availability in 20 southern British Columbia orchard soils was examined in the greenhouse. Zinc concentration, uptake and yield in navy beans (Phaseolus vulgaris) were measured and compared with soil Zn extracted by MgCl/sub 2/ at three concentrations (1.0 M, 0.50 and 0.25 M), DTPA, 0.10 M HCl and 0.05 M HCl + 0.0125 M H/sub 2/SO/sub 4/. Adding Zn at the rate of 10 mg/kg did not increase yields. Available Zn varied greatly as measured by the soil tests and by plant Zn concentration and uptake. These availability indices, except for plant Zn concentration, varied directly with Bray-P1 extractable P and organic matter content. Plant Zn uptake and concentration and MgCl/sub 2/ extractable Zn also varied inversely with pH. Zinc extracted by MgCl/sub 2/ was more closely related to plant Zn concentration and uptake than Zn extracted by the other three extractants. Furthermore, extraction of Zn with 0.25 M MgCl/sub 2/ instead of with 1.0 M MgCl/sub 2/ decreased analytical difficulties with atomic absorption spectrophotometry and also resulted in improved relationships with plant Zn concentration. Comparisons between Zn and Mn extracted by MgCl/sub 2/ solutions ranging from 1.0 M to 0.01 M in strength and at different soil:extractant ratios indicated that 0.25 M MgCl/sub 2/ extracted less specifically adsorbed Zn than 1.0 M MgCl/sub 2/ which resulted in the improved relationship with plant Zn.

  2. Operational and design strategies to improve PFBC power plant efficiency

    SciTech Connect

    Romeo, L.M.; Cortes, C.; Martinez, D.

    1998-07-01

    Nowadays the state of the art of PFBC technology lies halfway between the demonstration stage in units of intermediate size (72--79 MWe) and the commercial availability of larger scale plants. The operation of existing power stations has demonstrated that several points remain widely open to improvements. Due to fuel quality effects and the use of retrofitted plants, the PFBC power plant efficiency presently demands significant improvements. Likewise, the high energy efficiencies offered by the PFBC concept had not been completely demonstrated. To overcome these difficulties and further develop the technology a semiempirical model of a pressurized fluidized bed power plant has been developed. The model has been validated with actual plant data, being able to predict the Escatron (Spain) PFBC power plant behavior under different operating conditions. It has been widely tested to study not only the fluidized bed behavior, but also the influence of fluidized bed variables in the rest of the power plant. Good agreement has been found between the computed results and actual plant data at different operational regimes for the most important variables of the power plant. The main aim of this model is to study different strategies to improve the efficiency in the power plant. These strategies include: the improvement of soot blowing schedules of external heat exchangers; air preheating system optimization; selection of operational set-points that bring the highest efficiency; evaluation of the efficiency improvements due to design changes (changes in retrofitted steam turbines and heat exchangers, natural gas reburning, selection of different types of coal). This paper describes the model developed, the strategies to improve efficiency, as well as its results, and as conclusions, point out the improvements and perspectives for future work.

  3. The plant availability of auto-cast platinum group elements.

    PubMed

    Hooda, P S; Miller, A; Edwards, A C

    2008-04-01

    The introduction of automobile catalysts has raised environmental concern, as this pollution control technology is also an emission source for platinum group elements (PGE). The main aim of this study was to assess soil and grass PGE concentrations in soils adjacent to five road networks. The soil and grass samples were collected from four distances at each site; they were 0, 1, 2 and 5 m from the road edges. The maximum soil Pt, Rh and Pd concentrations were measured at the road perimeters. Pd concentrations were much higher than Pt or Rh, possibly due to differences in its use, emission and/or soil chemistry. Rh and Pt soil concentrations accounted for 66 and 34% (P < 0.01) of the variability observed, respectively, in their plant concentrations. Grass Pd concentrations had no relationship with its total soil concentrations.

  4. Improving web site performance using commercially available analytical tools.

    PubMed

    Ogle, James A

    2010-10-01

    It is easy to accurately measure web site usage and to quantify key parameters such as page views, site visits, and more complex variables using commercially available tools that analyze web site log files and search engine use. This information can be used strategically to guide the design or redesign of a web site (templates, look-and-feel, and navigation infrastructure) to improve overall usability. The data can also be used tactically to assess the popularity and use of new pages and modules that are added and to rectify problems that surface. This paper describes software tools used to: (1) inventory search terms that lead to available content; (2) propose synonyms for commonly used search terms; (3) evaluate the effectiveness of calls to action; (4) conduct path analyses to targeted content. The American Academy of Orthopaedic Surgeons (AAOS) uses SurfRay's Behavior Tracking software (Santa Clara CA, USA, and Copenhagen, Denmark) to capture and archive the search terms that have been entered into the site's Google Mini search engine. The AAOS also uses Unica's NetInsight program to analyze its web site log files. These tools provide the AAOS with information that quantifies how well its web sites are operating and insights for making improvements to them. Although it is easy to quantify many aspects of an association's web presence, it also takes human involvement to analyze the results and then recommend changes. Without a dedicated resource to do this, the work often is accomplished only sporadically and on an ad hoc basis.

  5. Improving stroke outcome: the benefits of increasing availability of technology.

    PubMed Central

    Heller, R. F.; Langhorne, P.; James, E.

    2000-01-01

    INTRODUCTION: A decision analysis was performed to explore the potential benefits of interventions to improve the outcome of patients admitted to hospital with a stroke, in the context of the technology available in different parts of the world. METHODS: The outcome of death or dependency was used with a six-month end-point. RESULTS: Four settings were identified that would depend on the resources available. The proportion of stroke patients who were dead or dependent at six months was 61.5% with no intervention at all. Setting 4, with the only intervention being the delayed introduction of aspirin, produced a 0.5% absolute improvement in outcome (death or dependency), and the addition of an organized stroke unit (Setting 3) produced the largest incremental improvement, of 2.7%. Extra interventions associated with non-urgent computed tomography and thus the ability to avoid anticoagulation or aspirin for those with a haemorrhagic stroke (Setting 2), and immediate computed tomography scanning to allow the use of thrombolytics in non-haemorrhagic stroke (Setting 1), produced only small incremental benefits of 0.4% in each case. DISCUSSION: To reduce the burden of illness due to stroke, efforts at primary prevention are essential and likely to have a greater impact than even the best interventions after the event. In the absence of good primary prevention, whatever is possible must be done to reduce the sequelae of stroke. This analysis provides a rational basis for beginning the development of clinical guidelines applicable to the economic setting of the patient. PMID:11143194

  6. Optimal Plant Carbon Allocation Implies a Biological Control on Nitrogen Availability

    NASA Astrophysics Data System (ADS)

    Prentice, I. C.; Stocker, B. D.

    2015-12-01

    The degree to which nitrogen availability limits the terrestrial C sink under rising CO2 is a key uncertainty in carbon cycle and climate change projections. Results from ecosystem manipulation studies and meta-analyses suggest that plant C allocation to roots adjusts dynamically under varying degrees of nitrogen availability and other soil fertility parameters. In addition, the ratio of biomass production to GPP appears to decline under nutrient scarcity. This reflects increasing plant C exudation into the soil (Cex) with decreasing nutrient availability. Cex is consumed by an array of soil organisms and may imply an improvement of nutrient availability to the plant. Thus, N availability is under biological control, but incurs a C cost. In spite of clear observational support, this concept is left unaccounted for in Earth system models. We develop a model for the coupled cycles of C and N in terrestrial ecosystems to explore optimal plant C allocation under rising CO2 and its implications for the ecosystem C balance. The model follows a balanced growth approach, accounting for the trade-offs between leaf versus root growth and Cex in balancing C fixation and N uptake. We assume that Cex is proportional to root mass, and that the ratio of N uptake (Nup) to Cex is proportional to inorganic N concentration in the soil solution. We further assume that Cex is consumed by N2-fixing processes if the ratio of Nup:Cex falls below the inverse of the C cost of N2-fixation. Our analysis thereby accounts for the feedbacks between ecosystem C and N cycling and stoichiometry. We address the question of how the plant C economy will adjust under rising atmospheric CO2 and what this implies for the ecosystem C balance and the degree of N limitation.

  7. 78 FR 66892 - BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ..., ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or... produced through genetic engineering that are plant pests or that there is reason to believe are plant...

  8. Metabolomics for Plant Improvement: Status and Prospects

    PubMed Central

    Kumar, Rakesh; Bohra, Abhishek; Pandey, Arun K.; Pandey, Manish K.; Kumar, Anirudh

    2017-01-01

    Post-genomics era has witnessed the development of cutting-edge technologies that have offered cost-efficient and high-throughput ways for molecular characterization of the function of a cell or organism. Large-scale metabolite profiling assays have allowed researchers to access the global data sets of metabolites and the corresponding metabolic pathways in an unprecedented way. Recent efforts in metabolomics have been directed to improve the quality along with a major focus on yield related traits. Importantly, an integration of metabolomics with other approaches such as quantitative genetics, transcriptomics and genetic modification has established its immense relevance to plant improvement. An effective combination of these modern approaches guides researchers to pinpoint the functional gene(s) and the characterization of massive metabolites, in order to prioritize the candidate genes for downstream analyses and ultimately, offering trait specific markers to improve commercially important traits. This in turn will improve the ability of a plant breeder by allowing him to make more informed decisions. Given this, the present review captures the significant leads gained in the past decade in the field of plant metabolomics accompanied by a brief discussion on the current contribution and the future scope of metabolomics to accelerate plant improvement. PMID:28824660

  9. Power plant productivity improvement in New York

    SciTech Connect

    1981-03-01

    The New York Public Service Commission (PSC), under contract with the US Department of Energy (DOE), began a joint program in September 1978 to improve the productivity of coal and nuclear electric generating units in New York State. The project had dual objectives: to ensure that the utilities in New York State have or develop a systematic permanent, cost-effective productivity improvement program based on sound engineering and economic considerations, and to develop a model program for Power Plant Productivity Improvement, which, through DOE, can also be utilized by other regulatory commissions in the country. To accomplish these objectives, the program was organized into the following sequence of activities: compilation and analysis of power plant performance data; evaluation and comparison of utility responses to outage/derating events; power plant productivity improvement project cost-benefit analysis; and evaluation of regulatory procedures and policies for improving productivity. The program that developed for improving the productivity of coal units is substantially different than for nuclear units. Each program is presented, and recommendations are made for activities of both the utilities and regulatory agencies which will promote improved productivity.

  10. Foliage Plants for Improving Indoor Air Quality

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.

    1988-01-01

    NASA's research with foliage houseplants during the past 10 years has produced a new concept in indoor air quality improvement. This new and exciting technology is quite simple. Both plant leaves and roots are utilized in removing trace levels of toxic vapors from inside tightly sealed buildings. Low levels of chemicals such as carbon monoxide and formaldehyde can be removed from indoor environments by plant leaves alone, while higher concentrations of numerous toxic chemicals can be removed by filtering indoor air through the plant roots surrounded by activated carbon. The activated carbon absorbs large quantities of the toxic chemicals and retains them until the plant roots and associated microorganisms degrade and assimilate these chemicals.

  11. Role of RNA interference in plant improvement

    NASA Astrophysics Data System (ADS)

    Jagtap, Umesh Balkrishna; Gurav, Ranjit Gajanan; Bapat, Vishwas Anant

    2011-06-01

    Research to alter crops for their better performance involving modern technology is underway in numerous plants, and achievements in transgenic plants are impacting crop improvements in unparalleled ways. Striking progress has been made using genetic engineering technology over the past two decades in manipulating genes from diverse and exotic sources, and inserting them into crop plants for inducing desirable characteristics. RNA interference (RNAi) has recently been identified as a natural mechanism for regulation of gene expression in all higher organisms from plants to humans and promises greater accuracy and precision to plant improvement. The expression of any gene can be down-regulated in a highly explicit manner exclusive of affecting the expression of any other gene by using RNAi technologies. Additional research in this field has been focused on a number of other areas including microRNAs, hairpin RNA, and promoter methylation. Manipulating new RNAi pathways, which generate small RNA molecules to amend gene expression in crops, can produce new quality traits and having better potentiality of protection against abiotic and biotic stresses. Nutritional improvement, change in morphology, or enhanced secondary metabolite synthesis are some of the other advantages of RNAi technology. In addition to its roles in regulating gene expression, RNAi is also used as a natural defense mechanism against molecular parasites such as jumping genes and viral genetic elements that affect genome stability. Even though much advancement has been made on the field of RNAi over the preceding few years, the full prospective of RNAi for crop improvement remains to be fully realized. The intricacy of RNAi pathway, the molecular machineries, and how it relates to plant development are still to be explained.

  12. Effects of permafrost thaw on nitrogen availability and plant nitrogen acquisition in Interior Alaska

    NASA Astrophysics Data System (ADS)

    Finger, R.; Euskirchen, E. S.; Turetsky, M.

    2013-12-01

    progressive N limitations, resulting in the dominance of plants with higher NUE. This likely has implications for plant litter quality, and could inhibit decomposition processes. We are collecting additional data to compare species-level NUE and nutrient resorption efficiency. We also will measure δ15N of aboveground plant organs, roots, soil, and pore water to explore sources of plant N, which we expect will influenced rooting depth as permafrost thaws as well as differences in mycorrhizal associations along our thaw gradient. Because thawing permafrost soils are anticipated to mobilize large amounts of N from soils, our results will improve our understanding of how permafrost thaw influences vegetation and soil N pools, soil N availability, and plant nutrition.

  13. IMPROVING TACONITE PROCESSING PLANT EFFICIENCY BY COMPUTER SIMULATION, Final Report

    SciTech Connect

    William M. Bond; Salih Ersayin

    2007-03-30

    This project involved industrial scale testing of a mineral processing simulator to improve the efficiency of a taconite processing plant, namely the Minorca mine. The Concentrator Modeling Center at the Coleraine Minerals Research Laboratory, University of Minnesota Duluth, enhanced the capabilities of available software, Usim Pac, by developing mathematical models needed for accurate simulation of taconite plants. This project provided funding for this technology to prove itself in the industrial environment. As the first step, data representing existing plant conditions were collected by sampling and sample analysis. Data were then balanced and provided a basis for assessing the efficiency of individual devices and the plant, and also for performing simulations aimed at improving plant efficiency. Performance evaluation served as a guide in developing alternative process strategies for more efficient production. A large number of computer simulations were then performed to quantify the benefits and effects of implementing these alternative schemes. Modification of makeup ball size was selected as the most feasible option for the target performance improvement. This was combined with replacement of existing hydrocyclones with more efficient ones. After plant implementation of these modifications, plant sampling surveys were carried out to validate findings of the simulation-based study. Plant data showed very good agreement with the simulated data, confirming results of simulation. After the implementation of modifications in the plant, several upstream bottlenecks became visible. Despite these bottlenecks limiting full capacity, concentrator energy improvement of 7% was obtained. Further improvements in energy efficiency are expected in the near future. The success of this project demonstrated the feasibility of a simulation-based approach. Currently, the Center provides simulation-based service to all the iron ore mining companies operating in northern

  14. Kriging as a Means of Improving WAAS Availability

    NASA Technical Reports Server (NTRS)

    Sparks, Lawrence; Blanch, Juan; Pandya, Nitin

    2010-01-01

    The Wide Area Augmentation System (WAAS), an augmentation of the Global Positioning System (GPS), provides safe and reliable use of GPS signals for airline navigation over much of North America. Currently the largest source of positioning error in the system is signal delay caused by the ionosphere. To allow the user to take account of such error, WAAS computes and broadcasts ionospheric vertical delays at a set of regularly-spaced grid points. In addition, WAAS computes and broadcasts a safety-critical integrity bound at each ionospheric grid point (IGP) called the Grid Ionospheric Vertical Error (GIVE). GIVEs are constructed to be sufficiently large to protect the user against positioning error due to the presence of ionospheric irregularity. In the initial operating capability (IOC) of WAAS, the vertical delay estimate at each IGP is determined from a planar fit of neighboring slant delay measurements, projected to vertical using an obliquity factor specified by the standard thin-shell model of the ionosphere. In WAAS Follow-On (WFO) Release 3, however, the vertical delay will be estimated by an established, geo-statistical technique known as kriging. Compared to the planar fit model, the kriging model is found, in general, to match better the observed random structure of the vertical delay. This paper presents the kriging methodology that will be used to estimate the vertical delay and its uncertainty at each IGP, and it assesses the subsequent improvement in WAAS availability enabled by kriging.

  15. Kriging as a Means of Improving WAAS Availability

    NASA Technical Reports Server (NTRS)

    Sparks, Lawrence; Blanch, Juan; Pandya, Nitin

    2010-01-01

    The Wide Area Augmentation System (WAAS), an augmentation of the Global Positioning System (GPS), provides safe and reliable use of GPS signals for airline navigation over much of North America. Currently the largest source of positioning error in the system is signal delay caused by the ionosphere. To allow the user to take account of such error, WAAS computes and broadcasts ionospheric vertical delays at a set of regularly-spaced grid points. In addition, WAAS computes and broadcasts a safety-critical integrity bound at each ionospheric grid point (IGP) called the Grid Ionospheric Vertical Error (GIVE). GIVEs are constructed to be sufficiently large to protect the user against positioning error due to the presence of ionospheric irregularity. In the initial operating capability (IOC) of WAAS, the vertical delay estimate at each IGP is determined from a planar fit of neighboring slant delay measurements, projected to vertical using an obliquity factor specified by the standard thin-shell model of the ionosphere. In WAAS Follow-On (WFO) Release 3, however, the vertical delay will be estimated by an established, geo-statistical technique known as kriging. Compared to the planar fit model, the kriging model is found, in general, to match better the observed random structure of the vertical delay. This paper presents the kriging methodology that will be used to estimate the vertical delay and its uncertainty at each IGP, and it assesses the subsequent improvement in WAAS availability enabled by kriging.

  16. Auxins as one of the factors of plant growth improvement by plant growth promoting rhizobacteria.

    PubMed

    Ahmed, Ambreen; Hasnain, Shahida

    2014-01-01

    Plant growth promoting rhizobacteria (PGPR) promote plant growth by various mechanisms such as phytohormone production, enhanced water and nutrient uptake, improved nitrogen availability in the soil, production of ACC-deaminase for ethylene breakdown, phosphate solubilization, siderophore production etc. Microbial auxin production is the major factor not only responsible for strengthening the plant-microbe relationship but it also promotes plant growth and development in a positive manner. Thus, bacterial auxin production potential can be exploited for plant growth improvement that may be effective in reducing the hazardous effects of chemical fertilizers on the ecosystem used to obtain higher yields. The present review gives a better understanding of various factors and mechanisms involved in auxin production by PGPR that may be helpful in proper exploitation of these natural resources in a beneficial way.

  17. Does Accelerated Soil Organic Matter Decomposition in the Presence of Plants Increase Plant N Availability?

    USDA-ARS?s Scientific Manuscript database

    Plant roots can increase microbial activity and soil organic matter (SOM) decomposition via rhizosphere priming effects. It is virtually unknown how differences in the priming effect among plant species and soil type affect N mineralization and plant uptake. In a greenhouse experiment, we tested whe...

  18. Efficiency improvement of thermal coal power plants

    SciTech Connect

    Hourfar, D.

    1996-12-31

    The discussion concerning an increase of the natural greenhouse effect by anthropogenic changes in the composition of the atmosphere has increased over the past years. The greenhouse effect has become an issue of worldwide debate. Carbon dioxide is the most serious emission of the greenhouse gases. Fossil-fired power plants have in the recent past been responsible for almost 30 % of the total CO{sub 2} emissions in Germany. Against this background the paper will describe the present development of CO{sub 2} emissions from power stations and present actual and future opportunities for CO{sub 2} reduction. The significance attached to hard coal as one of today`s prime sources of energy with the largest reserves worldwide, and, consequently, its importance for use in power generation, is certain to increase in the years to come. The further development of conventional power plant technology, therefore, is vital, and must be carried out on the basis of proven operational experience. The main incentive behind the development work completed so far has been, and continues to be, the achievement of cost reductions and environmental benefits in the generation of electricity by increasing plant efficiency, and this means that, in both the short and the long term, power plants with improved conventional technology will be used for environmentally acceptable coal-fired power generation.

  19. Geostatistical interpolation of available copper in orchard soil as influenced by planting duration.

    PubMed

    Fu, Chuancheng; Zhang, Haibo; Tu, Chen; Li, Lianzhen; Luo, Yongming

    2016-10-31

    Mapping the spatial distribution of available copper (A-Cu) in orchard soils is important in agriculture and environmental management. However, data on the distribution of A-Cu in orchard soils is usually highly variable and severely skewed due to the continuous input of fungicides. In this study, ordinary kriging combined with planting duration (OK_PD) is proposed as a method for improving the interpolation of soil A-Cu. Four normal distribution transformation methods, namely, the Box-Cox, Johnson, rank order, and normal score methods, were utilized prior to interpolation. A total of 317 soil samples were collected in the orchards of the Northeast Jiaodong Peninsula. Moreover, 1472 orchards were investigated to obtain a map of planting duration using Voronoi tessellations. The soil A-Cu content ranged from 0.09 to 106.05 with a mean of 18.10 mg kg(-1), reflecting the high availability of Cu in the soils. Soil A-Cu concentrations exhibited a moderate spatial dependency and increased significantly with increasing planting duration. All the normal transformation methods successfully decreased the skewness and kurtosis of the soil A-Cu and the associated residuals, and also computed more robust variograms. OK_PD could generate better spatial prediction accuracy than ordinary kriging (OK) for all transformation methods tested, and it also provided a more detailed map of soil A-Cu. Normal score transformation produced satisfactory accuracy and showed an advantage in ameliorating smoothing effect derived from the interpolation methods. Thus, normal score transformation prior to kriging combined with planting duration (NSOK_PD) is recommended for the interpolation of soil A-Cu in this area.

  20. Isotopic values of plants in relation to water availability in the Eastern Mediterranean region.

    PubMed

    Hartman, Gideon; Danin, Avinoam

    2010-04-01

    Plant C and N isotope values often correlate with rainfall on global and regional scales. This study examines the relationship between plant isotopic values and rainfall in the Eastern Mediterranean region. The results indicate significant correlations between both C and N isotope values and rainfall in C(3) plant communities. This significant relationship is maintained when plant communities are divided by plant life forms. Furthermore, a seasonal increase in C isotope values is observed during the dry season while N isotope values remain stable across the wet and dry seasons. Finally, the isotopic pattern in plants originating from desert environments differs from those from Mediterranean environments because some desert plants obtain most of their water from secondary sources, namely water channeled by local topographic features rather than direct rainfall. From these results it can be concluded that water availability is the primary factor controlling C and N isotope variability in plant communities in the Eastern Mediterranean.

  1. Maturing Weapon Systems for Improved Availability at Lower Costs

    DTIC Science & Technology

    1994-01-01

    1916 35537 NS-d~94-4M6 RAND is a nonprofit institution that seeks to improve public: policy throqgh research and analysis. RAND~’publcations do not...necessarily reflect the opinions or policies of its research sponsors. Published 1994 by RAMD 170 Main Steet, P.O. Box 2138, Santa Monica, CA 9M47-218 TO...performance and of savings in support costs. The research reported here was conducted under a project entitled An Evolving Action Planfor Implmenting Weapon

  2. Improving the efficacy of plant polyphenols.

    PubMed

    Biasutto, Lucia; Mattarei, Andrea; Sassi, Nicola; Azzolini, Michele; Romio, Matteo; Paradisi, Cristina; Zoratti, Mario

    2014-01-01

    Plant polyphenols exhibit potentially useful effects in a wide variety of pathophysiological settings. They interact with proteins such as signalling kinases, transcription factors and ion channels, and modulate redox processes, such as those taking place in mitochondria. Biomedical applications of these natural compounds are however severely hindered by their low bioavailability, rapid metabolism, and often by unfavourable physico-chemical properties, e.g. a generally low water solubility. Derivatives are under development with the aim of improving their bioavailability and/or bioefficacy. Various strategies can be adopted. An increase in circulating blood levels of non-metabolized natural compound may be attainable through prodrugs. In the ideal prodrug, phenolic hydroxyls are protected by capping groups which a) help or at least do not hinder permeation of epithelia; b) prevent conjugative modifications during absorption and first-pass through the liver; c) are eliminated with opportune kinetics to regenerate the parent compound. Moreover, prodrugs may be designed with the goals of modulating physical properties of the parent compound, and/or changing its distribution in the body. A more specific action may be achieved by concentrating the compounds at specific sites of action. An example of the second approach is represented by mitochondria-targeted redox-active polyphenol derivatives, designed to intervene on radical processes in these organelles and as a tool either to protect cells from oxidative insults or to precipitate their death. Mitochondrial targeting can be achieved through conjugation with a triphenylphosphonium lipophilic cation. Quercetin and resveratrol were chosen as model polyphenols for these proof-of-concept studies. Data available at the moment show that both quercetin and resveratrol mitochondria-targeted derivatives are pro-oxidant and cytotoxic in vitro, selectively killing fast-growing and tumoural cells when supplied in the low

  3. Recycling potential of secondary phosphorus resources as assessed by integrating substance flow analysis and plant-availability.

    PubMed

    Hamilton, Helen A; Brod, Eva; Hanserud, Ola; Müller, Daniel B; Brattebø, Helge; Haraldsen, Trond K

    2017-01-01

    The plant-availability of phosphorus (P) plays a central role in the ability of secondary P resources to replace mineral fertilizer. This is because secondary P plant-availability varies, often with large fractions of residual P that has no immediate fertilization effect. Therefore, if low quality secondary P fertilizers are applied, they will accumulate in soils that, in the long run, may increase the risk of P runoff and eutrophication. Substance flow analyses (SFA), used to identify potentials for improved P management, have not considered this well-known quality barrier. We, therefore, argue that traditional SFA over-estimates the fertilizer potential of secondary P resources. Using Norway as a case, we present a plant-availability extended SFA methodology that integrates SFA and the concept of relative agronomic efficiency. To account for the plant-available soil P stock and long-term soil interactions, we adjust the Norwegian P fertilization demand based on soil P values. We found that, while the method has uncertainties particularly for long-term estimations, it more realistically estimates secondary P fertilizer potentials and is adaptable to other countries. For Norway, we found the overall secondary P fertilizer potential reduced by 6-55% when considering plant-availability. The most important secondary resource was manure, which had the highest P plant-availability and quantities large enough (10.9kt plant-available P/yr) to meet Norway's entire P fertilization demand (5.8kt plant-available P/yr). However, barriers related to its transportability need to be overcome to efficiently use this resource. Fish sludge was also an important product, with 6.1kt plant-available P/yr but with uncertain plant-availability data. We argue that high quality secondary P resources can theoretically meet Norway's P fertilization demand and, therefore, make Norway mineral P independent. However, it is important that their use is carefully regulated based on plant-availability

  4. Availability, diversification and versatility explain human selection of introduced plants in Ecuadorian traditional medicine.

    PubMed

    Hart, G; Gaoue, Orou G; de la Torre, Lucía; Navarrete, Hugo; Muriel, Priscilla; Macía, Manuel J; Balslev, Henrik; León-Yánez, Susana; Jørgensen, Peter; Duffy, David Cameron

    2017-01-01

    Globally, a majority of people use plants as a primary source of healthcare and introduced plants are increasingly discussed as medicine. Protecting this resource for human health depends upon understanding which plants are used and how use patterns will change over time. The increasing use of introduced plants in local pharmacopoeia has been explained by their greater abundance or accessibility (availability hypothesis), their ability to cure medical conditions that are not treated by native plants (diversification hypothesis), or as a result of the introduced plants' having many different simultaneous roles (versatility hypothesis). In order to describe the role of introduced plants in Ecuador, and to test these three hypotheses, we asked if introduced plants are over-represented in the Ecuadorian pharmacopoeia, and if their use as medicine is best explained by the introduced plants' greater availability, different therapeutic applications, or greater number of use categories. Drawing on 44,585 plant-use entries, and the checklist of >17,000 species found in Ecuador, we used multi-model inference to test if more introduced plants are used as medicines in Ecuador than expected by chance, and examine the support for each of the three hypotheses above. We find nuanced support for all hypotheses. More introduced plants are utilized than would be expected by chance, which can be explained by geographic distribution, their strong association with cultivation, diversification (except with regard to introduced diseases), and therapeutic versatility, but not versatility of use categories. Introduced plants make a disproportionately high contribution to plant medicine in Ecuador. The strong association of cultivation with introduced medicinal plant use highlights the importance of the maintenance of human-mediated environments such as homegardens and agroforests for the provisioning of healthcare services.

  5. Native plants fare better against an introduced competitor with native microbes and lower nitrogen availability.

    PubMed

    Gaya Shivega, W; Aldrich-Wolfe, Laura

    2017-01-24

    While the soil environment is generally acknowledged as playing a role in plant competition, the relative importance of soil resources and soil microbes in determining outcomes of competition between native and exotic plants has rarely been tested. Resilience of plant communities to invasion by exotic species may depend on the extent to which native and exotic plant performance are mediated by abiotic and biotic components of the soil. We used a greenhouse experiment to compare performance of two native prairie plant species and one exotic species, when grown in intraspecific competition and when each native was grown in interspecific competition with the exotic species, in the presence and absence of a native prairie soil community, and when nitrogen availability was elevated or was maintained at native prairie levels. We found that elevated nitrogen availability was beneficial to the exotic species and had no effect on or was detrimental to the native plant species, that the native microbial community was beneficial to the native plant species and either had no effect or was detrimental to the exotic species, and that intraspecific competition was stronger than interspecific competition for the exotic plant species and vice-versa for the natives. Our results demonstrate that soil nitrogen availability and the soil microbial community can mediate the strength of competition between native and exotic plant species. We found no evidence for native microbes enhancing the performance of the exotic plant species. Instead, loss of the native soil microbial community appears to reinforce the negative effects of elevated N on native plant communities and its benefits to exotic invasive species. Resilience of plant communities to invasion by exotic plant species is facilitated by the presence of an intact native soil microbial community and weakened by anthropogenic inputs of nitrogen.

  6. Using a journal availability study to improve access

    PubMed Central

    Shaw-Kokot, Julia; de la Varre, Claire

    2001-01-01

    Purpose: Identify journal collection access and use factors. Setting and Subjects: University of North Carolina at Chapel Hill's Health Sciences Library patrons. Methodology: Survey forms and user interactions were monitored once a week for twelve weeks during the fall 1997 semester. The project was based on a 1989 New Mexico State University study and used Kantor's Branching Analysis to measure responses. Result: 80% of reported sought journal articles were found successfully. Along with journal usage data, the library obtained demographic and behavioral information. Discussion and Conclusions: Journals are the library's most used resource and, even as more electronic journals are offered, print journals continue to make up the majority of the collection. Several factors highlighted the need to study journal availability. User groups indicated that finding journals was problematic, and internal statistics showed people requesting interlibrary loans for owned items. The study looked at success rates, time, and ease of finding journals. A variety of reasons contributed to not finding journals. While overall user reports indicated relatively high success rate and satisfaction, there were problems to be addressed. As the library proceeds in redesigning both the physical space and electronic presence, the collected data have provided valuable direction. PMID:11209797

  7. Effects of nitrogen source and water availability on stem carbohydrates and cellulosic bioethanol traits of alfalfa plants.

    PubMed

    Fiasconaro, M Laura; Gogorcena, Yolanda; Muñoz, Fernando; Andueza, Donato; Sánchez-Díaz, Manuel; Antolín, M Carmen

    2012-08-01

    Symbiotic association of legumes with rhizobia frequently results in higher photosynthesis and soluble carbohydrates in comparison with nitrate-fed plants, which might improve its potential for biomass conversion into bioethanol. A greenhouse experiment was conducted to examine the effects of nitrogen source and water availability on stem characteristics and on relationships between carbohydrates, phenolic metabolism activity and cell wall composition in alfalfa (Medicago sativa L. cv. Aragón). The experiment included three treatments: (1) plants fed with ammonium nitrate (AN); (2) plants inoculated with rhizobia (R); and (3) plants inoculated with rhizobia and amended with sewage sludge (RS). Two levels of irrigation were imposed: (1) well-watered and (2) drought stress. Under well-watered conditions, nitrogen-fixing plants have increased photosynthesis and stem fermentable carbohydrate concentrations, which result in higher potential for biomass conversion to bioethanol than in AN plants. The latter had higher lignin due to enhanced activities of phenolic metabolism-related enzymes. Under drought conditions, the potential for bioethanol conversion decreased to a similar level in all treatments. Drought-stressed nitrogen-fixing plants have high concentrations of fermentable carbohydrates and cell wall cellulose, but ammonium nitrate-fed plants produced higher plant and stem biomass, which might compensate the decreasing stem carbohydrates and cellulose concentrations.

  8. Plant Nitrogen Acquisition Under Low Availability: Regulation of Uptake and Root Architecture.

    PubMed

    Kiba, Takatoshi; Krapp, Anne

    2016-04-01

    Nitrogen availability is a major factor determining plant growth and productivity. Plants acquire nitrogen nutrients from the soil through their roots mostly in the form of ammonium and nitrate. Since these nutrients are scarce in natural soils, plants have evolved adaptive responses to cope with the environment. One of the most important responses is the regulation of nitrogen acquisition efficiency. This review provides an update on the molecular determinants of two major drivers of the nitrogen acquisition efficiency: (i) uptake activity (e.g. high-affinity nitrogen transporters) and (ii) root architecture (e.g. low-nitrogen-availability-specific regulators of primary and lateral root growth). Major emphasis is laid on the regulation of these determinants by nitrogen supply at the transcriptional and post-transcriptional levels, which enables plants to optimize nitrogen acquisition efficiency under low nitrogen availability. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  9. Limitations to postfire seedling establishment: The role of seeding technology, water availability, and invasive plant abundance

    Treesearch

    Jeremy J. James; Tony. Svejcar

    2010-01-01

    Seeding rangeland following wildfire is a central tool managers use to stabilize soils and inhibit the spread of invasive plants. Rates of successful seeding on arid rangeland, however, are low. The objective of this study was to determine the degree to which water availability, invasive plant abundance, and seeding technology influence postfire seedling establishment...

  10. Plant-hummingbird interactions and temporal nectar availability in a restinga from Brazil.

    PubMed

    Fonseca, Lorena C N; Vizentin-Bugoni, Jeferson; Rech, André R; Alves, Maria Alice S

    2015-01-01

    Hummingbirds are the most important and specialized group of pollinating birds in the Neotropics and their interactions with plants are key components to many communities. In the present study we identified the assemblage of plants visited by hummingbirds and investigated the temporal availability of floral resources in an area of restinga, sandy plain coastal vegetation associated with the Atlantic forest, in Southeastern Brazil. We recorded flower and nectar features, flowering phenology and interactions between plants and hummingbirds and estimated the amount of calories produced per hectare from June 2005 to August 2006. Ten plant species were visited by two hummingbirds, Amazilia fimbriata and Eupetomena macroura. Resource availability was highly variable among plant species and over time. Nectar volume and concentration per flower were similar to other Neotropical hummingbird-visited plant assemblages. The estimated nectar resource availability between months varied from 0.85 to 5.97 Kcal per hectare/day, demanding an area between one and 6.8 ha to support a single hummingbird. Our study reports an unusual tropical setting where almost all interactions between hummingbirds and plants were performed by a single hummingbird species, A. fimbriata. Hence, the variable nectar availability is probably influencing hummingbird movements, its foraging area, and consequently plant pollination.

  11. Availability, diversification and versatility explain human selection of introduced plants in Ecuadorian traditional medicine

    PubMed Central

    Gaoue, Orou G.; de la Torre, Lucía; Navarrete, Hugo; Muriel, Priscilla; Macía, Manuel J.; Balslev, Henrik; León-Yánez, Susana; Jørgensen, Peter; Duffy, David Cameron

    2017-01-01

    Globally, a majority of people use plants as a primary source of healthcare and introduced plants are increasingly discussed as medicine. Protecting this resource for human health depends upon understanding which plants are used and how use patterns will change over time. The increasing use of introduced plants in local pharmacopoeia has been explained by their greater abundance or accessibility (availability hypothesis), their ability to cure medical conditions that are not treated by native plants (diversification hypothesis), or as a result of the introduced plants’ having many different simultaneous roles (versatility hypothesis). In order to describe the role of introduced plants in Ecuador, and to test these three hypotheses, we asked if introduced plants are over-represented in the Ecuadorian pharmacopoeia, and if their use as medicine is best explained by the introduced plants’ greater availability, different therapeutic applications, or greater number of use categories. Drawing on 44,585 plant-use entries, and the checklist of >17,000 species found in Ecuador, we used multi-model inference to test if more introduced plants are used as medicines in Ecuador than expected by chance, and examine the support for each of the three hypotheses above. We find nuanced support for all hypotheses. More introduced plants are utilized than would be expected by chance, which can be explained by geographic distribution, their strong association with cultivation, diversification (except with regard to introduced diseases), and therapeutic versatility, but not versatility of use categories. Introduced plants make a disproportionately high contribution to plant medicine in Ecuador. The strong association of cultivation with introduced medicinal plant use highlights the importance of the maintenance of human-mediated environments such as homegardens and agroforests for the provisioning of healthcare services. PMID:28886104

  12. Biotechnological Advancements for Improving Floral Attributes in Ornamental Plants

    PubMed Central

    Noman, Ali; Aqeel, Muhammad; Deng, Jianming; Khalid, Noreen; Sanaullah, Tayyaba; Shuilin, He

    2017-01-01

    Developing new ornamental cultivars with improved floral attributes is a major goal in floriculture. Biotechnological approach together with classical breeding methods has been used to modify floral color, appearance as well as for increasing disease resistance. Transgenic strategies possess immense potential to produce novel flower phenotypes that are not found in nature. Adoption of Genetic engineering has supported the idea of floral trait modification. Ornamental plant attributes like floral color, fragrance, disease resistance, and vase life can be improved by means of genetic manipulation. Therefore, we witness transgenic plant varieties of high aesthetic and commercial value. This review focuses on biotechnological advancements in manipulating key floral traits that contribute in development of diverse ornamental plant lines. Data clearly reveals that regulation of biosynthetic pathways related to characteristics like pigment production, flower morphology and fragrance is both possible and predictable. In spite of their great significance, small number of genetically engineered varieties of ornamental plants has been field tested. Today, novel flower colors production is regarded as chief commercial benefit obtained from transgenic plants. But certain other floral traits are much more important and have high commercial potential. Other than achievements such as novel architecture, modified flower color, etc., very few reports are available regarding successful transformation of other valuable horticultural characteristics. Our review also summarized biotechnological efforts related to enhancement of fragrance and induction of early flowering along with changes in floral anatomy and morphology. PMID:28473834

  13. Biotechnological Advancements for Improving Floral Attributes in Ornamental Plants.

    PubMed

    Noman, Ali; Aqeel, Muhammad; Deng, Jianming; Khalid, Noreen; Sanaullah, Tayyaba; Shuilin, He

    2017-01-01

    Developing new ornamental cultivars with improved floral attributes is a major goal in floriculture. Biotechnological approach together with classical breeding methods has been used to modify floral color, appearance as well as for increasing disease resistance. Transgenic strategies possess immense potential to produce novel flower phenotypes that are not found in nature. Adoption of Genetic engineering has supported the idea of floral trait modification. Ornamental plant attributes like floral color, fragrance, disease resistance, and vase life can be improved by means of genetic manipulation. Therefore, we witness transgenic plant varieties of high aesthetic and commercial value. This review focuses on biotechnological advancements in manipulating key floral traits that contribute in development of diverse ornamental plant lines. Data clearly reveals that regulation of biosynthetic pathways related to characteristics like pigment production, flower morphology and fragrance is both possible and predictable. In spite of their great significance, small number of genetically engineered varieties of ornamental plants has been field tested. Today, novel flower colors production is regarded as chief commercial benefit obtained from transgenic plants. But certain other floral traits are much more important and have high commercial potential. Other than achievements such as novel architecture, modified flower color, etc., very few reports are available regarding successful transformation of other valuable horticultural characteristics. Our review also summarized biotechnological efforts related to enhancement of fragrance and induction of early flowering along with changes in floral anatomy and morphology.

  14. Improving plant bioaccumulation science through consistent reporting of experimental data.

    PubMed

    Fantke, Peter; Arnot, Jon A; Doucette, William J

    2016-10-01

    Experimental data and models for plant bioaccumulation of organic contaminants play a crucial role for assessing the potential human and ecological risks associated with chemical use. Plants are receptor organisms and direct or indirect vectors for chemical exposures to all other organisms. As new experimental data are generated they are used to improve our understanding of plant-chemical interactions that in turn allows for the development of better scientific knowledge and conceptual and predictive models. The interrelationship between experimental data and model development is an ongoing, never-ending process needed to advance our ability to provide reliable quality information that can be used in various contexts including regulatory risk assessment. However, relatively few standard experimental protocols for generating plant bioaccumulation data are currently available and because of inconsistent data collection and reporting requirements, the information generated is often less useful than it could be for direct applications in chemical assessments and for model development and refinement. We review existing testing guidelines, common data reporting practices, and provide recommendations for revising testing guidelines and reporting requirements to improve bioaccumulation knowledge and models. This analysis provides a list of experimental parameters that will help to develop high quality datasets and support modeling tools for assessing bioaccumulation of organic chemicals in plants and ultimately addressing uncertainty in ecological and human health risk assessments.

  15. Physiological phenotyping of plants for crop improvement.

    PubMed

    Ghanem, Michel Edmond; Marrou, Hélène; Sinclair, Thomas R

    2015-03-01

    Future progress in crop breeding requires a new emphasis in plant physiological phenotyping for specific, well-defined traits. Success in physiological phenotyping to identify parents for use in breeding efforts for improved cultivars has been achieved by employing a multi-tier screening approach with different levels of sophistication and trait resolution. Subsequently, cultivar development required an integrated mix of classical breeding approaches and one or more tiers of phenotyping to identify genotypes expressing the desired trait. The role of high throughput systems can be useful; here, we emphasize that this approach is likely to offer useful results at an initial tier of phenotyping and will need to be complemented with more directed tiers of phenotyping. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Current understanding on ethylene signaling in plants: the influence of nutrient availability.

    PubMed

    Iqbal, Noushina; Trivellini, Alice; Masood, Asim; Ferrante, Antonio; Khan, Nafees A

    2013-12-01

    The plant hormone ethylene is involved in many physiological processes, including plant growth, development and senescence. Ethylene also plays a pivotal role in plant response or adaptation under biotic and abiotic stress conditions. In plants, ethylene production often enhances the tolerance to sub-optimal environmental conditions. This role is particularly important from both ecological and agricultural point of views. Among the abiotic stresses, the role of ethylene in plants under nutrient stress conditions has not been completely investigated. In literature few reports are available on the interaction among ethylene and macro- or micro-nutrients. However, the published works clearly demonstrated that several mineral nutrients largely affect ethylene biosynthesis and perception with a strong influence on plant physiology. The aim of this review is to revisit the old findings and recent advances of knowledge regarding the sub-optimal nutrient conditions on the effect of ethylene biosynthesis and perception in plants. The effect of deficiency or excess of the single macronutrient or micronutrient on the ethylene pathway and plant responses are reviewed and discussed. The synergistic and antagonist effect of the different mineral nutrients on ethylene plant responses is critically analyzed. Moreover, this review highlights the status of information between nutritional stresses and plant response, emphasizing the topics that should be further investigated. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  17. Total quality drives nuclear plant improvements

    SciTech Connect

    Richey, R.B. )

    1991-01-01

    Total quality (TQ) at Carolina Power and Light (CP and L) is fulfilling a 1985 vision of Sherwood H. Smith, Jr., CP and L's chairman, president, and chief executive officer. The TQ concept has provided a way for employees to align their creative energies toward meeting the business needs of the company. Throughout CP and L, TQ has been recognized as the vehicle for reducing operating costs and improving customer satisfaction. Within the nuclear organization, application of the TQ process has helped to improve communications, resolve challenges, and provide more consistent work practices among CP and L's three nuclear plants. Total quality was introduced from the top down, with initial benefits coming from team interactions. Senior management at CP and L defined the corporate expectations and outlined the training requirements for implementing TQ. Management staffs at each organizational level became steering committees for TQ team activities within their departments. Teams of employees most knowledgeable about a given work area were empowered to solve problems or overcome obstacles related to that work area. Employees learned to become better team players and to appreciate the quality of decisions reached through group consensus. Now, formalized methods that started TQ are becoming part of the day-to-day work ethic.

  18. Plant Nitrogen Acquisition Under Low Availability: Regulation of Uptake and Root Architecture

    PubMed Central

    Kiba, Takatoshi; Krapp, Anne

    2016-01-01

    Nitrogen availability is a major factor determining plant growth and productivity. Plants acquire nitrogen nutrients from the soil through their roots mostly in the form of ammonium and nitrate. Since these nutrients are scarce in natural soils, plants have evolved adaptive responses to cope with the environment. One of the most important responses is the regulation of nitrogen acquisition efficiency. This review provides an update on the molecular determinants of two major drivers of the nitrogen acquisition efficiency: (i) uptake activity (e.g. high-affinity nitrogen transporters) and (ii) root architecture (e.g. low-nitrogen-availability-specific regulators of primary and lateral root growth). Major emphasis is laid on the regulation of these determinants by nitrogen supply at the transcriptional and post-transcriptional levels, which enables plants to optimize nitrogen acquisition efficiency under low nitrogen availability. PMID:27025887

  19. Method to improve drought tolerance in plants

    DOEpatents

    Schroeder, Julian I.; Kwak, June Myoung

    2003-10-21

    A method to increase drought resistance in plants is provided. The method comprises inhibiting or disabling inward-rectifying K.sup.+ (K.sup.+.sub.in) channels in the stomatal guard cells of the plant.

  20. The economic valuation of improved process plant decision support technology.

    PubMed

    White, Douglas C

    2007-06-01

    How can investments that would potentially improve a manufacturing plant's decision process be economically justified? What is the value of "better information," "more flexibility," or "improved integration" and the technologies that provide these effects? Technology investments such as improved process modelling, new real time historians and other databases, "smart" instrumentation, better data analysis and visualization software, and/or improved user interfaces often include these benefits as part of their valuation. How are these "soft" benefits to be converted to a quantitative economic return? Quantification is important if rational management decisions are to be made about the correct amount of money to invest in the technologies, and which technologies to choose among the many available ones. Modelling the plant operational decision cycle-detect, analyse, forecast, choose and implement--provides a basis for this economic quantification. In this paper a new economic model is proposed for estimation of the value of decision support investments based on their effect upon the uncertainty in forecasting plant financial performance. This model leads to quantitative benefit estimates that have a realistic financial basis. An example is presented demonstrating the application of the method.

  1. A critical test of the two prevailing theories of plant response to nutrient availability.

    PubMed

    Rubio, Gerardo; Zhu, Jinming; Lynch, Jonathan P

    2003-01-01

    Whereas the "law of the minimum" (LM) states that plant growth is limited by a single resource at any one time, the "multiple limitation hypothesis" (MLH) proposes that optimum plant behavior results from balancing resource costs and benefits so that all resources limit plant growth simultaneously. We tested the hypothesis that neither the LM nor the MLH account for plant responses to all mineral nutrients. Fronds of the aquatic plant Lemna minor were grown in nutrient solutions with increasing levels of four nutrients: nitrogen, phosphorus, potassium, and magnesium. Neither LM or MLH adequately predicted plant responses to all of these nutrients: 23 of the 60 responses analyzed were classified as belonging to the LM; 20 cases were classified as undefined; and 17 cases as MLH. The type of response strongly depended on the specific pair of nutrients considered. The validity of the MLH model would depend on the accompanying resource limiting plant growth and on the severity of the stress. We propose that a "nutrient-specific" analysis, considering the biology of each mineral nutrient rather than grouping plant resources as a whole, is more appropriate than general models in understanding plant responses to nutrient availability.

  2. Pollination syndromes in a Caatinga plant community in northeastern Brazil: seasonal availability of floral resources in different plant growth habits.

    PubMed

    Quirino, Z G M; Machado, I C

    2014-02-01

    To describe plant phenological patterns and correlate functioning for the quantity and quality of resources available for the pollinator, it is crucial to understand the temporal dynamics of biological communities. In this way, the pollination syndromes of 46 species with different growth habits (trees, shrubs, herbs, and vines) were examined in an area of Caatinga vegetation, northeastern Brazil (7° 28' 45″ S and 36° 54' 18″ W), during two years. Flowering was monitored monthly in all the species, over two years (from January 2003 to December 2004). Pollination syndromes were characterised based on floral traits such as size, colour, morphology, symmetry, floral resources, as well as on direct visual observation of floral visitors on focal plants and published information. We observed differences among the plant growth habits with respect to floral traits, types of resources offered, and floral syndromes. The flowering periods of the species varied among floral syndrome groups. The majority of the melittophilous species flowered during the rainy season in the two study years, while the species of the other pollination syndroms flowered at the end of the dry season. An asynchrony of flowering was noted among the chiropterophilous species, while the phalenophilous group concentrated during the rainy season. The overall availability of floral resources was different during the rainy and the dry seasons, and also it varied among plants with different growth habits. The availability of oil-flowers coincided with the period of low nectar availability. We observed a relationship between the temporal distribution of the pollination syndromes and the availability of floral resources among each growth habits in this tropical ecosystem. Resource allocation in seasonal environments, such as the Caatinga, can function as a strategy for maintaining pollinators, facilitating therefore the reproductive success of plant species. The availability of floral resources during

  3. Metal/metalloid fixation by litter during decomposition affected by silicon availability during plant growth.

    PubMed

    Schaller, Jörg

    2013-03-01

    Organic matter is known to accumulate high amounts of metals/metalloids, enhanced during the process of decomposition by heterotrophic biofilms (with high fixation capacity for metals/metalloids). The colonization by microbes and the decay rate of the organic matter depends on different litter properties. Main litter properties affecting the decomposition of organic matter such as the nutrient ratios and the content of cellulose, lignin and phenols are currently described to be changed by silicon availability. But less is known about the impact of silicon availability during plant growth on elemental fixation during decay. Hence, this research focuses on the impact of silicon availability during plant growth on fixation of 42 elements during litter decay, by controlling the litter properties. The results of this experiment are a significantly higher metal/metalloid accumulation during decomposition of plant litter grown under low silicon availability. This may be explained by the altered litter properties (mainly nutrient content) affecting the microbial decomposition of the litter, the microbial growth on the litter and possibly by the silicon double layer, which is evident in leaf litter with high silicon content and reduces the binding sites for metals/metalloids. Furthermore, this silicon double layer may also reduce the growing biofilm by reducing the availability of carbon compounds at the litter surface and has to be elucidated in further research. Hence, low silicon availability during plant growth enhances the metal/metalloid accumulation into plant litter during aquatic decomposition. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. The influence of maintenance system reliability and maintainability characteristics on overall plant availability

    SciTech Connect

    Prince, B.E.; Haire, M.J.

    1991-01-01

    Performance goals for complex processes are often linked with achieving high availability of plant equipment. This requires that maintenance systems, which sometimes include complex electromechanical equipment operating in a hostile environment, meet certain requirements for reliability and maintainability. This paper develops several Markov probability models to evaluate the impact of maintenance system availability on the overall plant. The models considered included the case when the maintenance equipment is itself under repair when a failure occurs on process equipment. Examination was also given to the situation where the maintenance equipment is operated in a degraded condition (i.e., longer times are required to complete repairs). The results of the analysis identified conditions under which failures in the maintenance system could have a significant adverse effect on plant availability. Maintenance system failures affect the average times required for process repairs, which can affect the availability of each process subsystem in the plant. A useful simple rule for incorporating effects of maintenance system failures into plant availability estimates is to multiply repair rates corresponding to ideal conditions (no maintenance failures) by the expected availability of the maintenance system. This rule applies when the maintenance system is available on a standby status when a process failure occurs. The effect is somewhat greater when the maintenance equipment is subject to interim breakdowns, between process failures. The analysis also indicated conditions under which overall plant availability could benefit by permitting some degradation in maintenance equipment capabilities, before repairing this equipment with a backup system. As a rough rule, the degradation should not increase average repair times by more than about a factor of two.

  5. Carbon Allocation in Mojave Desert Plant-Soil Systems as Affected by Nitrogen and Water Availability

    NASA Astrophysics Data System (ADS)

    Verburg, P. S.; Kapitzke, S. E.

    2008-12-01

    Changes in atmospheric nitrogen (N) deposition due to increased urbanization and precipitation due to climate change are likely to affect carbon (C) allocation in plants and soils in arid ecosystems in the Southwestern United States where net primary production is often limited by N and water availability. We conducted a greenhouse study to determine the effects of N and water availability on one year old creosote (Larrea tridentata) plants, the dominant shrub in the Mojave Desert. In our greenhouse study we employed two N levels (0 and 40 kg ha-1) and two soil moisture levels (7% and 15%). We grew creosote seedlings in PVC columns filled with topsoil from the Mojave Global Change Facility at the Nevada Test Site. The columns were covered and sealed at the base of the plant to separate the above- from belowground plant compartment. Plants were distributed over two growth chambers receiving ambient light while day/night temperatures were set at 25° C/15° C. In one chamber plants were labeled once a week with 13C-enriched CO2 while a second chamber acted as an unlabeled control. Throughout the six month study we measured soil CO2 concentrations, respired CO2 as well as their isotopic signatures. At the end of the study plants were harvested and we measured plant above- and belowground biomass and isotopic composition of the vegetation. In addition, we measured isotopic composition of soil organic and inorganic C. Increased N availability stimulated stem weight and decreased total C losses through soil respiration. Other plant and soil parameters including isotopic composition were not affected by changes in N availability. Increased soil moisture stimulated plant biomass mainly due to an increase in leaf weight while root biomass tended to decrease. Soil CO2 concentrations increased with increasing water availability despite a reduction in root biomass. The isotopic data showed that net new C uptake increased mostly in leaves, soil organic matter and soil

  6. Plant Foliar Response to Soil Nutrient Availability Across Contrasting Geologic Settings

    NASA Astrophysics Data System (ADS)

    Castle, S. C.; Neff, J. C.

    2007-12-01

    Rock derived mineral nutrients such as P, Ca, Mg, Mn, and K play a significant, but poorly understood role in the structure and function of temperate forest ecosystems. Though these nutrients are not necessarily limiting to plant growth, they are essential to plant physiological functioning. In this study, we test the hypothesis that foliar nutrients are a proxy for soil nutrient availability across sites of different underlying geologies. Specifically, we focus on the plant nutrient-use strategies of rock derived nutrients (P and K) and how they relate to soil nutrient status. In order to assess the responses of plant species to nutrient availability, we monitored above ground net primary productivity (current annual increment + litterfall), plant chemistry, and soil nutrients for a period of 24 months. This research was completed in the San Juan Mountain region of southern Colorado, where there is a high local diversity of bedrock geochemistry. Within this region, two small sub-alpine basins were chosen; a sedimentary basin composed of Mesozoic cyclic limestone, sandstone & shale and a volcanic basin composed of Tertiary rhyolite. Across these basins, geology played a significant role in explaining the variability of rock derived nutrient availability. Initial results suggest that differences in bedrock geochemistry have little influence on the aboveground net primary production (ANPP) of plants or on the chemistry of foliar materials. This inflexibility of foliar chemistry to variations in nutrient availability suggests that genetic and physiologic controls play a strong role in determining the chemical content of plant materials. An alternative hypothesis is that deposition of eolian mineral dust into subalpine systems could play a role in offsetting the reliance of vegetation on deeper bedrock derived nutrient sources. An investigation is currently underway to assess the contribution of eolian dust derived nutrients to plant nutrition using Sr as a geochemical

  7. Cyanobacterial-based approaches to improving photosynthesis in plants.

    PubMed

    Zarzycki, Jan; Axen, Seth D; Kinney, James N; Kerfeld, Cheryl A

    2013-01-01

    Plants rely on the Calvin-Benson (CB) cycle for CO(2) fixation. The key carboxylase of the CB cycle is ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Efforts to enhance carbon fixation in plants have traditionally focused on RubisCO or on approaches that can help to remedy RubisCO's undesirable traits: its low catalytic efficiency and photorespiration. Towards reaching the goal of improving plant photosynthesis, cyanobacteria may be instrumental. Because of their evolutionary relationship to chloroplasts, they represent ideal model organisms for photosynthesis research. Furthermore, the molecular understanding of cyanobacterial carbon fixation provides a rich source of strategies that can be exploited for the bioengineering of chloroplasts. These strategies include the cyanobacterial carbon concentrating mechanism (CCM), which consists of active and passive transporter systems for inorganic carbon and a specialized organelle, the carboxysome. The carboxysome encapsulates RubisCO together with carbonic anhydrase in a protein shell, resulting in an elevated CO(2) concentration around RubisCO. Moreover, cyanobacteria differ from plants in the isoenzymes involved in the CB cycle and the photorespiratory pathways as well as in mechanisms that can affect the activity of RubisCO. In addition, newly available cyanobacterial genome sequence data from the CyanoGEBA project, which has more than doubled the amount of genomic information available for cyanobacteria, increases our knowledge on the CCM and the occurrence and distribution of genes of interest.

  8. Comparison of extractants for plant-available zinc, cadmium, nickel, and copper in contaminated soils

    SciTech Connect

    Haq, A.U.; Bates, T.E.; Soon, Y.K.

    1980-07-01

    The objective of this study was to find a suitable extractant(s) for plant-available metals in metal contaminated soils. Swiss chard (Beta vulgaris L. Fordhook Giant) was grown in greenhouse pots on 46 Ontario soils varying in degree of contamination with metals. The soils had been contaminated with metals to varying degrees over a period of years. After 40 days, the plants were harvested and Zn, Cd, Ni, and Cu concentrations were measured. Each soil was extracted with nine different extractants: aqua regia, 0.01M EDTA, 0.005M DTPA, 0.02M NTA, 0.5N CH/sub 3/COOH, 1N CH/sub 3/COONH/sub 4/, 0.6N HCl + 0.05N AlCl/sub 3/, (COOH)/sub 2/ + (COONH/sub 4/)/sub 2/, and H/sub 2/O. Zinc, cadmium, nickel, and copper concentrations in Swiss chard were correlated with the amounts of soil Zn, Cd, Ni, and Cu removed by each extractant. Of the nine soil extractants, CH/sub 3/COONH/sub 4/ was the best predictor of plant-available Zn if only extractable Zn and soil pH were included as independent variables in a regression equation. Acetic acid was the best extractant for prediction of both plant-available Cd and Ni when soil pH was included in the equation. Attempts to find a suitable soil extractant for plant-available Cu were unsuccessful.

  9. Use of the BCR sequential extraction procedure for the study of metal availability to plants.

    PubMed

    Li, Junhui; Lu, Ying; Shim, Hojae; Deng, Xianglian; Lian, Jin; Jia, Zhenglei; Li, Jianhua

    2010-02-01

    To investigate the mobility and availability of metals from soil to plant, concentrations of zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) in topsoils and plants (lettuce, scallion, celery, tomato, carambola, wampee and longan) collected from the area around a petrochemical complex in Guangzhou, China, were analyzed. The modified European Community Bureau of Reference (BCR) three-step sequential extraction procedure was applied to determine the concentration of metal fractions in soils. The results showed that the distribution of Zn, Cu, Pb and Cd in four fractions varied greatly among the soil samples, and 18.8% of vegetable and fruit samples for Cd and 5.8% for Pb exceeded the maximum permissible levels in food of China. Soil-to-plant transfer coefficients were in the order of Cd>Zn>Cu>Hg>As>Pb, suggesting Cd being the most mobile and available to plants among the metals studied. Principal component analysis indicated that metal fractions and soil physicochemical properties (pH, organic matter, cation exchange capacity, clay content and electrical conductivity) affected metal uptake by plants. Furthermore, atmospheric deposition may be another important factor for the accumulation of metals in plants.

  10. Elevated concentrations of trace elements in soil do not necessarily reflect metals available to plants.

    PubMed

    Antonious, George F; Silitonga, Maifan R; Tsegaye, Teferi D; Unrine, Jason M; Coolong, Timothy; Snyder, John C

    2013-01-01

    Bioaccumulation and entry of trace elements from soil into the food chain have made trace-elements major environmental pollutants. The main objective of this investigation was to study the impact of mixing native agricultural soil with municipal sewage sludge (SS) or SS mixed with yard waste (SS+YW) compost on total concentration of trace elements in soil, metals available to plants, and mobility of metals from soil into peppers and melon fruits. Regardless of soil treatment, the average concentrations of Ni, Cd, Pb, Cr, Cu, Zn, and Mo in melon fruits were 5.2, 0.7, 3.9, 0.9, 34.3, 96.1, and 3.5μg g(-1), respectively. Overall concentrations of Ni, Cd, Pb, and Zn in melon fruits were significantly greater (P < 0.05) than pepper fruits. No significant differences were found in Cr, Cu, and Mo concentrations between pepper and melon fruits at harvest time. Total metal concentrations and metal ions in soil available to melon and pepper plants were also determined. Total concentration of each metal in the soil was significantly greater than concentration of metal ions available to plants. Elevated Ni and Mo bioaccumulation factor (BAF > 1) of melon fruits of plants grown in SS+YW mixed soil is a characteristic that would be less favorable when plants grown on sites having high concentrations of these metals.

  11. Improving Nutritional Quality of Plant Proteins Through Genetic Engineering

    PubMed Central

    Le, Dung Tien; Chu, Ha Duc; Le, Ngoc Quynh

    2016-01-01

    Humans and animals are unable to synthesize essential amino acids such as branch chain amino acids methionine (Met), lysine (Lys) and tryptophan (Trp). Therefore, these amino acids need to be supplied through the diets. Several essential amino acids are deficient or completely lacking among crops used for human food and animal feed. For example, soybean is deficient in Met; Lys and Trp are lacking in maize. In this mini review, we will first summarize the roles of essential amino acids in animal nutrition. Next, we will address the question: “What are the amino acids deficient in various plants and their biosynthesis pathways?” And: “What approaches are being used to improve the availability of essential amino acids in plants?” The potential targets for metabolic engineering will also be discussed, including what has already been done and what remains to be tested. PMID:27252589

  12. Improvement of water treatment at thermal power plants

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Bushuev, E. N.; Larin, A. B.; Karpychev, E. A.; Zhadan, A. V.

    2015-04-01

    Prospective and existing technologies for water treatment at thermal power plants, including pretreatment, ion exchange, and membrane method are considered. The results obtained from laboratory investigations and industrial tests of the proposed technologies carried out at different thermal power plants are presented. The possibilities of improving the process and environmental indicators of water treatment plants are shown.

  13. Improving pumping system efficiency at coal plants

    SciTech Connect

    Livoti, W.C.; McCandless, S.; Poltorak, R.

    2009-03-15

    The industry must employ ultramodern technologies when building or upgrading power plant pumping systems thereby using fuels more efficiently. The article discusses the uses and efficiencies of positive displacement pumps, centrifugal pumps and multiple screw pumps. 1 ref., 4 figs.

  14. ALA Pretreatment Improves Waterlogging Tolerance of Fig Plants.

    PubMed

    An, Yuyan; Qi, Lin; Wang, Liangju

    2016-01-01

    5-aminolevulinic acid (ALA), a natural and environmentally friendly plant growth regulator, can improve plant tolerance to various environmental stresses. However, whether ALA can improve plant waterlogging tolerance is unknown. Here, we investigated the effects of ALA pretreatment on the waterlogging-induced damage of fig (Ficus carica Linn.) plants, which often suffer from waterlogging stress. ALA pretreatment significantly alleviated stress-induced morphological damage, increased leaf relative water content (RWC), and reduced leaf superoxide anion ([Formula: see text]) production rate and malonaldehyde (MDA) content in fig leaves, indicating ALA mitigates waterlogging stress of fig plants. We further demonstrated that ALA pretreatment largely promoted leaf chlorophyll content, photosynthetic electron transfer ability, and photosynthetic performance index, indicating ALA significantly improves plant photosynthetic efficiency under waterlogging stress. Moreover, ALA pretreatment significantly increased activities of leaf superoxide dismutase (SOD) and peroxidase (POD), root vigor, and activities of root alcohol dehydrogenase (ADH), and lactate dehydrogenase (LDH), indicating ALA also significantly improves antioxidant ability and root function of fig plants under waterlogging stress. Taken together, ALA pretreatment improves waterlogging tolerance of fig plants significantly, and the promoted root respiration, leaf photosynthesis, and antioxidant ability may contribute greatly to this improvement. Our data firstly shows that ALA can improve plant waterlogging tolerance.

  15. ALA Pretreatment Improves Waterlogging Tolerance of Fig Plants

    PubMed Central

    An, Yuyan; Qi, Lin; Wang, Liangju

    2016-01-01

    5-aminolevulinic acid (ALA), a natural and environmentally friendly plant growth regulator, can improve plant tolerance to various environmental stresses. However, whether ALA can improve plant waterlogging tolerance is unknown. Here, we investigated the effects of ALA pretreatment on the waterlogging-induced damage of fig (Ficus carica Linn.) plants, which often suffer from waterlogging stress. ALA pretreatment significantly alleviated stress-induced morphological damage, increased leaf relative water content (RWC), and reduced leaf superoxide anion (O2⋅¯) production rate and malonaldehyde (MDA) content in fig leaves, indicating ALA mitigates waterlogging stress of fig plants. We further demonstrated that ALA pretreatment largely promoted leaf chlorophyll content, photosynthetic electron transfer ability, and photosynthetic performance index, indicating ALA significantly improves plant photosynthetic efficiency under waterlogging stress. Moreover, ALA pretreatment significantly increased activities of leaf superoxide dismutase (SOD) and peroxidase (POD), root vigor, and activities of root alcohol dehydrogenase (ADH), and lactate dehydrogenase (LDH), indicating ALA also significantly improves antioxidant ability and root function of fig plants under waterlogging stress. Taken together, ALA pretreatment improves waterlogging tolerance of fig plants significantly, and the promoted root respiration, leaf photosynthesis, and antioxidant ability may contribute greatly to this improvement. Our data firstly shows that ALA can improve plant waterlogging tolerance. PMID:26789407

  16. Compositions and methods for improved plant feedstock

    SciTech Connect

    Shen, Hui; Chen, Fang; Dixon, Richard A

    2014-12-02

    The invention provides methods for modifying lignin content and composition in plants and achieving associated benefits therefrom involving altered expression of newly discovered MYB4 transcription factors. Nucleic acid constructs for modifying MYB4 transcription factor expression are described. By over-expressing the identified MYB4 transcription factors, for example, an accompanying decrease in lignin content may be achieved. Plants are provided by the invention comprising such modifications, as are methods for their preparation and use.

  17. Role of soil adsorption and microbial degradation on dissipation of mesotrione in plant available soil water

    USDA-ARS?s Scientific Manuscript database

    Mesotrione is a carotenoid biosynthesis-inhibiting herbicide labeled for pre-emergence and post emergent weed control in corn production. Understanding the factors that influence the dissipation of mesotrione in soil and in the plant available water (PAW) is important for both the environmental fat...

  18. Proceedings of the international conference on nuclear power plant aging, availability factor and reliability analysis

    SciTech Connect

    Goel, V.S.

    1985-01-01

    This book presents the papers given at a conference on nuclear power plant life extension. Topics considered at the conference included availability, accelerated aging techniques, the qualification of electrical equipment, probabilistic risk assessment, reactor maintenance, outages, reliability, computer-aided design, seismic effects, mechanical vibrations, fatigue monitoring, steam generators, and materials degradation by aging and embrittlement.

  19. Insects mediate the effects of propagule supply and resource availability on a plant invasion

    Treesearch

    Nathan J. Sanders; Jake F. Weltzin; Gregory M. Crutsinger; Matthew C. Fitzpatrick; Martin A. Nunez; Christopher M. Oswalt; Kristin E. Lane

    2007-01-01

    Invasive species are a global threat to biodiversity and the functioning of natural ecosystems. Here, we report on a two-year experiment aimed at elucidating the combined and relative effects of three key controls on plant invasions: propagule supply, soil nitrogen (N) availability, and herbivory by native insects. We focus on the exotic species Lespedeza...

  20. Hydrogen Cyanide in the Rhizosphere: Not Suppressing Plant Pathogens, but Rather Regulating Availability of Phosphate.

    PubMed

    Rijavec, Tomaž; Lapanje, Aleš

    2016-01-01

    Plant growth promoting rhizobacteria produce chemical compounds with different benefits for the plant. Among them, HCN is recognized as a biocontrol agent, based on its ascribed toxicity against plant pathogens. Based on several past studies questioning the validity of this hypothesis, we have re-addressed the issue by designing a new set of in vitro experiments, to test if HCN-producing rhizobacteria could inhibit the growth of phytopathogens. The level of HCN produced by the rhizobacteria in vitro does not correlate with the observed biocontrol effects, thus disproving the biocontrol hypothesis. We developed a new concept, in which HCN does not act as a biocontrol agent, but rather is involved in geochemical processes in the substrate (e.g., chelation of metals), indirectly increasing the availability of phosphate. Since this scenario can be important for the pioneer plants living in oligotrophic alpine environments, we inoculated HCN producing bacteria into sterile mineral sand together with germinating plants and showed that the growth of the pioneer plant French sorrel was increased on granite-based substrate. No such effect could be observed for maize, where plantlets depend on the nutrients stored in the endosperm. To support our concept, we used KCN and mineral sand and showed that mineral mobilization and phosphate release could be caused by cyanide in vitro. We propose that in oligotrophic alpine environments, and possibly elsewhere, the main contribution of HCN is in the sequestration of metals and the consequential indirect increase of nutrient availability, which is beneficial for the rhizobacteria and their plant hosts.

  1. Hydrogen Cyanide in the Rhizosphere: Not Suppressing Plant Pathogens, but Rather Regulating Availability of Phosphate

    PubMed Central

    Rijavec, Tomaž; Lapanje, Aleš

    2016-01-01

    Plant growth promoting rhizobacteria produce chemical compounds with different benefits for the plant. Among them, HCN is recognized as a biocontrol agent, based on its ascribed toxicity against plant pathogens. Based on several past studies questioning the validity of this hypothesis, we have re-addressed the issue by designing a new set of in vitro experiments, to test if HCN-producing rhizobacteria could inhibit the growth of phytopathogens. The level of HCN produced by the rhizobacteria in vitro does not correlate with the observed biocontrol effects, thus disproving the biocontrol hypothesis. We developed a new concept, in which HCN does not act as a biocontrol agent, but rather is involved in geochemical processes in the substrate (e.g., chelation of metals), indirectly increasing the availability of phosphate. Since this scenario can be important for the pioneer plants living in oligotrophic alpine environments, we inoculated HCN producing bacteria into sterile mineral sand together with germinating plants and showed that the growth of the pioneer plant French sorrel was increased on granite-based substrate. No such effect could be observed for maize, where plantlets depend on the nutrients stored in the endosperm. To support our concept, we used KCN and mineral sand and showed that mineral mobilization and phosphate release could be caused by cyanide in vitro. We propose that in oligotrophic alpine environments, and possibly elsewhere, the main contribution of HCN is in the sequestration of metals and the consequential indirect increase of nutrient availability, which is beneficial for the rhizobacteria and their plant hosts. PMID:27917154

  2. Guide for the assessment of the availability of gasification-combined-cycle power plants

    NASA Astrophysics Data System (ADS)

    Neely, M.

    1982-01-01

    A guide that can be used for predicting the reliability and availability of coal gasification-combined-cycle (GCC) electric power generation units, as well as other electric power generation unit types is given. A prediction of plant effectiveness, a measure that can be directly related to availability, equivalent availability, forced-outage rate, and other performance measures is given. A seven-step availability assessment methodology that uses the concepts of unit states and state capabilities (the power output capability associated with each state) to produce predictions of a unit's effectiveness, availability, equivalent availability, critical components, and other measures of interest is given. As an illustration, the method is used to prepare an assessment of an 1150-megawatt baseload GCC plant that employs seven gas turbines, one steam turbine, and six oxygen-blown (Texaco) gasifiers. A complete data base of failure rates and mean downtimes for the GCC plant components and a documented computer program used for this analysis are also included.

  3. Improved Economics of Nuclear Plant Life Management

    SciTech Connect

    Bond, Leonard J.; Doctor, Steven R.; Jarrell, Donald B.; Bond, Joseph W D.

    2007-07-31

    The adoption of new on-line monitoring, diagnostic and eventually prognostics technologies has the potential to impact the economics of the existing nuclear power plant fleet, new plants and future advanced designs. To move from periodic inspection to on-line monitoring for condition based maintenance and eventually prognostics will require advances in sensors, better understanding of what and how to measure within the plant; enhanced data interrogation, communication and integration; new predictive models for damage/aging evolution; system integration for real world deployments; quantification of uncertainties in what are inherently ill-posed problems and integration of enhanced condition based maintenance/prognostics philosophies into new plant designs, operation and O&M approaches. The move to digital systems in petrochemical, process and fossil fuel power plants is enabling major advances to occur in the instrumentation, controls and monitoring systems and approaches employed. The adoption within the nuclear power community of advanced on-line monitoring and advanced diagnostics has the potential for the reduction in costly periodic surveillance that requires plant shut-down , more accurate cost-benefit analysis, “just-in-time” maintenance, pre-staging of maintenance tasks, move towards true “operation without failures” and a jump start on advanced technologies for new plant concepts, such as those under the International Gen IV Program. There are significant opportunities to adopt condition-based maintenance when upgrades are implemented at existing facilities. The economic benefit from a predictive maintenance program based upon advanced on-line monitoring and advanced diagnostics can be demonstrated from a cost/benefit analysis. An analysis of the 104 US legacy systems has indicated potential savings at over $1B per year when applied to all key equipment; a summary of the supporting analysis is provided in this paper.

  4. Effect of commercially available plant-derived essential oil products on arthropod pests.

    PubMed

    Cloyd, Raymond A; Galle, Cindy L; Keith, Stephen R; Kalscheur, Nanette A; Kemp, Kenneth E

    2009-08-01

    Plant-derived essential oil products, in general, are considered minimum-risk pesticides and are exempt from Environmental Protection Agency registration under section 25(b) of the Federal Insecticide Fungicide and Rodenticide Act. However, many of the plant-derived essential products available to consumers (homeowners) have not been judiciously evaluated for both efficacy and plant safety. In fact, numerous plant-derived essential oil products labeled for control of arthropod pests have not been subject to rigorous evaluation, and there is minimal scientific information or supporting data associated with efficacy against arthropod pests. We conducted a series of greenhouse experiments to determine the efficacy and phytotoxicity of an array of plant-derived essential oil products available to consumers on arthropod pests including the citrus mealybug, Planococcus citri (Risso); western flower thrips, Frankliniella occidentalis (Pergande); twospotted spider mite, Tetranychus urticae Koch; sweetpotato whitefly B-biotype, Bemisia tabaci (Gennadius); and green peach aphid, Myzus persicae (Sulzer). Although the products Flower Pharm (cottonseed, cinnamon, and rosemary oil) and Indoor Pharm (soybean, rosemary, and lavender oil) provided > 90% mortality of citrus mealybug, they were also the most phytotoxic to the coleus, Solenostemon scutellarioides (L.) Codd, plants. Both GC-Mite (cottonseed, clove, and garlic oil) and Bugzyme (citric acid) were most effective against the twospotted spider mite (> or = 90% mortality). However, SMC (canola, coriander oil, and triethanolamine), neem (clarified hydrophobic extract of neem oil), and Bug Assassin (eugenol, sodium lauryl sulfate, peppermint, and citronella oil) provided > 80% mortality. Monterey Garden Insect Spray, which contained 0.5% spinosad, was most effective against western flower thrips with 100% mortality. All the other products evaluated failed to provide sufficient control of western flower thrips with < 30

  5. Enhancing Potentially Plant-Available Lead Concentrations in Contaminated Residential Soils Using a Biodegradable Chelating Agent

    NASA Astrophysics Data System (ADS)

    Andra, S.; Datta, R.; Sarkar, D.; Saminathan, S.

    2007-12-01

    Chelation of heavy metals is an important factor in enhancing metal solubility and, hence, metal availability to plants to promote phytoremediation. In the present study, we compared the effects of application of a biodegradable chelating agent, namely, ethylenediaminedisuccinic acid (EDDS) on enhancing plant available form of lead (Pb) in Pb-based paint contaminated residential soils compared to that of a more commonly used, but non-biodegradable chelate, i.e., ethylenediaminetetraacetic acid (EDTA). Development of a successful phytoremediation model for metals such as Pb depends on a thorough understanding of the physical and chemical properties of the soil, along with the optimization of a chelate treatment to mobilize Pb from `unavailable' pools to potentially plant available fraction. In this context, we set out to perform batch incubation experiments to investigate the effectiveness of the two aforementioned chelates in enhancing plant available Pb at four different concentrations (0, 5, 10 and 15 mM/kg soil) and three treatment durations (0, 10 and 30 days). We selected 12 contaminated residential soils from two major metropolitan areas (San Antonio, TX and Baltimore, MD) with varying soil physico-chemical properties - the soils from San Antonio were primarily alkaline and those from Baltimore were typically acidic. Total soil Pb concentrations ranged between 256 mg/kg and 4,182 mg/kg. Our results show that both chelates increased the solubility of Pb, otherwise occluded in the complex soil matrix. For both EDTA and EDDS, the exchangeable concentrations of soil Pb also increased with increase in chelate concentration and incubation time. The most effective treatment was 15 mM chelate kg-1 soil incubated for 30 days, which caused many fold increase in potentially plant available Pb (a combination of the soluble and exchangeable fractions) relative to the unamended controls. Step wise multiple linear regression analysis using chelate-extractable Pb and soil

  6. Plant allocation of carbon to defense as a function of herbivory, light and nutrient availability

    USGS Publications Warehouse

    DeAngelis, Donald L.; Ju, Shu; Liu, Rongsong; Bryant, John P.; Gourley, Stephen A.

    2012-01-01

    We use modeling to determine the optimal relative plant carbon allocations between foliage, fine roots, anti-herbivore defense, and reproduction to maximize reproductive output. The model treats these plant components and the herbivore compartment as variables. Herbivory is assumed to be purely folivory. Key external factors include nutrient availability, degree of shading, and intensity of herbivory. Three alternative functional responses are used for herbivory, two of which are variations on donor-dependent herbivore (models 1a and 1b) and one of which is a Lotka–Volterra type of interaction (model 2). All three were modified to include the negative effect of chemical defenses on the herbivore. Analysis showed that, for all three models, two stable equilibria could occur, which differs from most common functional responses when no plant defense component is included. Optimal strategies of carbon allocation were defined as the maximum biomass of reproductive propagules produced per unit time, and found to vary with changes in external factors. Increased intensity of herbivory always led to an increase in the fractional allocation of carbon to defense. Decreases in available limiting nutrient generally led to increasing importance of defense. Decreases in available light had little effect on defense but led to increased allocation to foliage. Decreases in limiting nutrient and available light led to decreases in allocation to reproduction in models 1a and 1b but not model 2. Increases in allocation to plant defense were usually accompanied by shifts in carbon allocation away from fine roots, possibly because higher plant defense reduced the loss of nutrients to herbivory.

  7. Interactive effects of plant-available soil silicon and herbivory on competition between two grass species

    PubMed Central

    Garbuzov, Mihail; Reidinger, Stefan; Hartley, Susan E.

    2011-01-01

    Background and Aims The herbivore defence system of true grasses (Poaceae) is predominantly based on silicon that is taken up from the soil and deposited in the leaves in the form of abrasive phytoliths. Silicon uptake mechanisms can be both passive and active, with the latter suggesting that there is an energetic cost to silicon uptake. This study assessed the effects of plant-available soil silicon and herbivory on the competitive interactions between the grasses Poa annua, a species that has previously been reported to accumulate only small amounts of silicon, and Lolium perenne, a high silicon accumulator. Methods Plants were grown in mono- and mixed cultures under greenhouse conditions. Plant-available soil silicon levels were manipulated by adding silicon to the soil in the form of sodium silicate. Subsets of mixed culture pots were exposed to above-ground herbivory by desert locusts (Schistocerca gregaria). Key Results In the absence of herbivory, silicon addition increased biomass of P. annua but decreased biomass of L. perenne. Silicon addition increased foliar silicon concentrations of both grass species >4-fold. Under low soil-silicon availability the herbivores removed more leaf biomass from L. perenne than from P. annua, whereas under high silicon availability the reverse was true. Consequently, herbivory shifted the competitive balance between the two grass species, with the outcome depending on the availability of soil silicon. Conclusions It is concluded that a complex interplay between herbivore abundance, growth–defence trade-offs and the availability of soil silicon in the grasses' local environment affects the outcome of inter-specific competition, and so has the potential to impact on plant community structure. PMID:21868406

  8. Reduced peroxisomal citrate synthase activity increases substrate availability for polyhydroxyalkanoate biosynthesis in plant peroxisomes.

    PubMed

    Tilbrook, Kimberley; Poirier, Yves; Gebbie, Leigh; Schenk, Peer M; McQualter, Richard B; Brumbley, Stevens M

    2014-10-01

    Polyhydroxyalkanoates (PHAs) are bacterial carbon storage polymers used as renewable, biodegradable plastics. PHA production in plants may be a way to reduce industrial PHA production costs. We recently demonstrated a promising level of peroxisomal PHA production in the high biomass crop species sugarcane. However, further production strategies are needed to boost PHA accumulation closer to commercial targets. Through exogenous fatty acid feeding of Arabidopsis thaliana plants that contain peroxisome-targeted PhaA, PhaB and PhaC enzymes from Cupriavidus necator, we show here that the availability of substrates derived from the β-oxidation cycle limits peroxisomal polyhydroxybutyrate (PHB) biosynthesis. Knockdown of peroxisomal citrate synthase activity using artificial microRNA increased PHB production levels approximately threefold. This work demonstrates that reduction of peroxisomal citrate synthase activity may be a valid metabolic engineering strategy for increasing PHA production in other plant species.

  9. Impact of hydrochar application on soil nutrient dynamics and plant availability

    NASA Astrophysics Data System (ADS)

    Bargmann, I.; Greef, J. M.; Kücke, M.

    2012-04-01

    In order to investigate potentials for the use of HTC-products (hydrochar) in agriculture, the influence of soil application of different hydrochars on soil nutrient dynamics as well as on plant growth and plant nutrient uptake was determined. Hydrochars were produced from sugar beet pulps and brewer's grains by carbonization at 190°C for 4 respectively 12 hours each. Incubation experiments with two soil types showed an increase of soil pH by 0.5 to 2.5 pH units, depending on the amount of hydrochar added and the process conditions (i.e. addition of calcium carbonate during production). The application of HTC to soil decreased the plant available nitrogen to almost zero in the first week after HTC-addition, followed by a slow re-release of nitrate in the following weeks. A similar immobilization of soluble phosphate was observed for one soil type, although to a lower extent. The plant availability of phosphorus in hydrochars and biochars is subject of current trials. Furthermore it is actually investigated to what extend the N immobilization is related to soil microbial activity. Germination tests with barley showed toxic effects of hydrochar application on germination, both by direct contact of grains with HTC as well as by release of gaseous compounds from HTC. Effects differ significantly for different parent materials and pretreatments (washing, drying, storage). The influence of HTC-addition to soil on plant growth and nutrient uptake was investigated in pot experiments with various crop species (barley, phaseolus bean, leek), comparing HTC from different parent materials and process parameters such as carbonization time. With increasing addition of HTC, the N availability was decreased and N contents in the plant were significantly lower compared with the untreated control. The plant growth response was different for each tested crop. On barley, leaf tip necroses were observed, but not on phaseolus. Biomass yield of barley and beans was generally increased

  10. Comparative evaluation of oxidative stress status and manganese availability in plants growing on manganese mine.

    PubMed

    Boojar, Massod Mashhadi Akbar; Goodarzi, Faranak

    2008-11-01

    This study pioneered an approach that determined the effects of excess manganese (Mn) on three species; Datura stramonium, Alhagi camelthorn and Chenopodium ambrosioides. We investigated their levels of Mn, antioxidative enzymes and oxidative damage biomarkers in plants (zone 1) in and outside (zone 2) the Mn mine. The results showed that total and available Mn were at toxic levels for plants growing on zone 1. The Mn levels in each plant species were higher in leaves, stems and roots. Mn was only accumulated significantly in leaf vacuoles of A. camelthorn. Antioxidative enzyme activities of C. ambrosioides and/or D. stramonium in zone 1 were higher in leaves, stems and then in their roots. Malondialdehyde (MDA) and dityrosine levels were insignificantly higher in tissues of the studied plants in zone 1 with respect to zone 2. The roots of studied plants showed significantly higher levels of these biomarkers in comparison with their leaves in zone 1. Accordingly, antioxidative enzymatic response to Mn-stress in D. stramonium and C. ambrosioides and possibly accumulation of Mn in leaf vacuoles of A. camelthorn, protected them from oxidative damages and involved in their tolerance in Mn mine.

  11. Enhanced growth of halophyte plants in biochar-amended coastal soil: roles of nutrient availability and rhizosphere microbial modulation.

    PubMed

    Zheng, Hao; Wang, Xiao; Chen, Lei; Wang, Zhenyu; Xia, Yang; Zhang, Yipeng; Wang, Hefang; Luo, Xianxiang; Xing, Baoshan

    2017-03-27

    Soil health is essential and irreplaceable for plant growth and global food production, which has been threatened by climate change and soil degradation. Degraded coastal soils are urgently required to reclaim using new sustainable technologies. Interest in applying biochar to improve soil health and promote crop yield has rapidly increased because of its multiple benefits. However, effects of biochar addition on the saline-sodic coastal soil health and halophyte growth were poorly understood. Response of two halophytes, Sesbania (Sesbania cannabina) and Seashore mallow (Kosteletzkya virginica), to the individual or co-application of biochar and inorganic fertilizer into a coastal soil was investigated using a 52-day pot experiment. The biochar alone or co-application stimulated the plant growth (germination, root development, biomass), primarily attributed to the enhanced nutrients availability from the biochar-improved soil health. Additionally, the promoted microbial activities and bacterial community shift towards the beneficial taxa (e.g., Pseudomonas and Bacillus) in the rhizosphere also contributed to the enhanced plant growth and biomass. Our findings showed the promising significance because biochar added at an optimal level (≤5%) could be a feasible option to reclaim the degraded coastal soil, enhance plant growth and production, and increase soil health and food security.

  12. The influence of earthworms on the mobility of microelements in soil and their availability for plants

    NASA Astrophysics Data System (ADS)

    Bityutskii, N. P.; Kaidun, P. I.

    2008-12-01

    The influence of earthworms ( Aporrectodea caliginosa, Lumbricus rubellus, L. terrestris, and Eisenia fetida) on the mobility of microelements and their availability for plants was studied. The contents of water-soluble Fe and Mn compounds extracted from the coprolites were 5-10 times higher than that in the soil (enriched in calcium carbonate and dried) consumed by the earthworms. This digestion-induced effect became higher with the age of the coprolites (up to 9 days) and took place under their alkalization. In the excreta (surface + enteric) of earthworms, the Fe concentration exceeded those of Mn and Zn by many times. Iron and manganese were mostly concentrated (>80% and >60%, respectively) in the organic part of the excrements. In the tests with hydroponics, the excreta were found to be a source of iron compounds available for plants that were similar to Fe2(SO4)3 or Fe-citrate by their physiological effect in the case when the Fe concentration in the excretions was above 0.7 μM. However, the single application of excreta of different earthworm species into the CaCO3 enriched soil did not significantly affect the plant (cucumber) nutrition. The analysis of the transport of microelements with xylem sap showed that this fact appeared to be due to the absence of an Fe deficit in the cucumber plants because of their high capability for the absorption of weakly soluble iron compounds.

  13. Glycosylation Is a Major Regulator of Phenylpropanoid Availability and Biological Activity in Plants

    PubMed Central

    Le Roy, Julien; Huss, Brigitte; Creach, Anne; Hawkins, Simon; Neutelings, Godfrey

    2016-01-01

    The phenylpropanoid pathway in plants is responsible for the biosynthesis of a huge amount of secondary metabolites derived from phenylalanine and tyrosine. Both flavonoids and lignins are synthesized at the end of this very diverse metabolic pathway, as well as many intermediate molecules whose precise biological functions remain largely unknown. The diversity of these molecules can be further increased under the action of UDP-glycosyltransferases (UGTs) leading to the production of glycosylated hydroxycinnamates and related aldehydes, alcohols and esters. Glycosylation can change phenylpropanoid solubility, stability and toxic potential, as well as influencing compartmentalization and biological activity. (De)-glycosylation therefore represents an extremely important regulation point in phenylpropanoid homeostasis. In this article we review recent knowledge on the enzymes involved in regulating phenylpropanoid glycosylation status and availability in different subcellular compartments. We also examine the potential link between monolignol glycosylation and lignification by exploring co-expression of lignin biosynthesis genes and phenolic (de)glycosylation genes. Of the different biological roles linked with their particular chemical properties, phenylpropanoids are often correlated with the plant's stress management strategies that are also regulated by glycosylation. UGTs can for instance influence the resistance of plants during infection by microorganisms and be involved in the mechanisms related to environmental changes. The impact of flavonoid glycosylation on the color of flowers, leaves, seeds and fruits will also be discussed. Altogether this paper underlies the fact that glycosylation and deglycosylation are powerful mechanisms allowing plants to regulate phenylpropanoid localisation, availability and biological activity. PMID:27303427

  14. Leaf nitrogen and phosphorus of temperate desert plants in response to climate and soil nutrient availability.

    PubMed

    He, Mingzhu; Dijkstra, Feike A; Zhang, Ke; Li, Xinrong; Tan, Huijuan; Gao, Yanhong; Li, Gang

    2014-11-06

    In desert ecosystems, plant growth and nutrient uptake are restricted by availability of soil nitrogen (N) and phosphorus (P). The effects of both climate and soil nutrient conditions on N and P concentrations among desert plant life forms (annual, perennial and shrub) remain unclear. We assessed leaf N and P levels of 54 desert plants and measured the corresponding soil N and P in shallow (0-10 cm), middle (10-40 cm) and deep soil layers (40-100 cm), at 52 sites in a temperate desert of northwest China. Leaf P and N:P ratios varied markedly among life forms. Leaf P was higher in annuals and perennials than in shrubs. Leaf N and P showed a negative relationship with mean annual temperature (MAT) and no relationship with mean annual precipitation (MAP), but a positive relationship with soil P. Leaf P of shrubs was positively related to soil P in the deep soil. Our study indicated that leaf N and P across the three life forms were influenced by soil P. Deep-rooted plants may enhance the availability of P in the surface soil facilitating growth of shallow-rooted life forms in this N and P limited system, but further research is warranted on this aspect.

  15. Leaf nitrogen and phosphorus of temperate desert plants in response to climate and soil nutrient availability

    PubMed Central

    He, Mingzhu; Dijkstra, Feike A.; Zhang, Ke; Li, Xinrong; Tan, Huijuan; Gao, Yanhong; Li, Gang

    2014-01-01

    In desert ecosystems, plant growth and nutrient uptake are restricted by availability of soil nitrogen (N) and phosphorus (P). The effects of both climate and soil nutrient conditions on N and P concentrations among desert plant life forms (annual, perennial and shrub) remain unclear. We assessed leaf N and P levels of 54 desert plants and measured the corresponding soil N and P in shallow (0–10 cm), middle (10–40 cm) and deep soil layers (40–100 cm), at 52 sites in a temperate desert of northwest China. Leaf P and N:P ratios varied markedly among life forms. Leaf P was higher in annuals and perennials than in shrubs. Leaf N and P showed a negative relationship with mean annual temperature (MAT) and no relationship with mean annual precipitation (MAP), but a positive relationship with soil P. Leaf P of shrubs was positively related to soil P in the deep soil. Our study indicated that leaf N and P across the three life forms were influenced by soil P. Deep-rooted plants may enhance the availability of P in the surface soil facilitating growth of shallow-rooted life forms in this N and P limited system, but further research is warranted on this aspect. PMID:25373739

  16. Computer control improves ethylene plant operation

    SciTech Connect

    Whitehead, B.D.; Parnis, M.

    1987-11-01

    ICIA Australia ordered a turnkey 250,000-tpy ethylene plant to be built at the Botany site, Sydney, Australia. Following a feasibility study, an additional order was placed for a process computer system for advanced process control and optimization. This article gives a broad outline of the process computer tasks, how the tasks were implemented, what problems were met, what lessons were learned and what results were achieved.

  17. Abattoir Wastewater Irrigation Increases the Availability of Nutrients and Influences on Plant Growth and Development.

    PubMed

    Matheyarasu, Raghupathi; Bolan, Nanthi S; Naidu, Ravi

    This study evaluated the effects of abattoir wastewater irrigation on plant growth and development. The soils used in this study were collected from Primo Smallgoods Abattoir (Port Wakefield, South Australia) at different sites such as currently irrigated (CI), currently not irrigated (CNI) and soil outside the irrigation area as control (CTRL). A completely randomised block design was employed for the plant growth experiment, where four crops (Pennisetum purpureum, Medicago sativa, Sinapis alba and Helianthus annuus) were grown separately on three different soils (CI, CNI and CTRL) in plastic pots. Two types of water (tap water and wastewater) and two loadings were applied throughout the planting period based on the field capacity (FC 100 and 150 %). The overall dry matter yield was compared between the soils and treatments. Under wastewater irrigation, among the four species grown in the CI soil, P. purpureum (171 g) and H. annuus (151 g) showed high biomass yields, followed by S. alba (115 g) and M. sativa (31 g). The plants grown under tap water showed about 70 % lower yields compared to the abattoir wastewater irrigation (AWW). Similar trends in the biomass yields were observed for CNI and CTRL soils under the two water treatments, with the biomass yields in the following order CI > CNI > CTRL soils. The results confirm the beneficial effects of AWW at the greenhouse level. However, a proper cropping pattern and wastewater irrigation management plan is essential to utilise the nutrients available in the wastewater-irrigated land treatment sites. The increase in fertility is evident from the effects of wastewater on biomass growth and also the abundance of nutrients accumulated in plants. A mass balance calculation on the applied, residual and the plant-accumulated nutrients over a few cropping periods will help us in understanding the nutrient cycling processes involved in the abattoir-irrigated land treatment sites, which will serve as an effective tool

  18. Specialist Insect Herbivore and Light Availability Do Not Interact in the Evolution of an Invasive Plant

    PubMed Central

    Zhang, Ziyan; He, Kate S.; Li, Bo

    2015-01-01

    Release from specialist insect herbivores may allow invasive plants to evolve traits associated with decreased resistance and increased competitive ability. Given that there may be genetic trade-off between resistance and tolerance, invasive plants could also become more tolerant to herbivores. Although it is widely acknowledged that light availability affects tolerance to herbivores, little information is available for whether the effect of light availability on tolerance differ between the introduced and native populations. We conducted a common garden experiment in the introduced range of Alternanthera philoxeroides using ten invasive US and ten native Argentinean populations at two levels of light availability and in the presence or absence of a specialist stem-boring insect Agasicles hygrophila. Plant biomass (total and storage root biomass), two allocation traits (root/shoot ratio and branch intensity, branches biomass/main stem biomass) and two functional traits (specific stem length and specific leaf area), which are potentially associated with herbivore resistance and light capture, were measured. Overall, we found that A. philoxeroides from introduced ranges had comparable biomass and tolerance to specialist herbivores, lower branch intensity, lower specific stem length and specific leaf area. Moreover, introduced populations displayed higher shade tolerance of storage root biomass and lower plastic response to shading in specific stem length. Finally, light availability had no significant effect on evolution of tolerance to specialist herbivores of A. philoxeroides. Our results suggest that post-introduction evolution might have occurred in A. philoxeroides. While light availability did not influence the evolution of tolerance to specialist herbivores, increased shade tolerance and release from specialist insects might have contributed to the successful invasion of A. philoxeroides. PMID:26407176

  19. Compressed Air System Optimization Project Improves Production at a Metal Forging Plant (Modern Forge, TN, Plant)

    SciTech Connect

    2000-12-01

    In 1995, Modern Forge of Tennessee implemented a compressed air system improvement project at its Piney Flats, Tennessee, forging plant. Due to the project’s implementation, the plant was able to operate with fewer compressors and improve its product quality, thus allowing it to increase productivity. The project also resulted in considerable energy and maintenance savings.

  20. OAK RIDGE NATIONAL LABORATORY SPALLATION NEUTRON SOURCE ELECTRICAL SYSTEMS AVAILABILITY AND IMPROVEMENTS

    SciTech Connect

    Cutler, Roy I; Peplov, Vladimir V; Wezensky, Mark W; Norris, Kevin Paul; Barnett, William E; Hicks, Jim; Weaver, Joey T; Moss, John; Rust, Kenneth R; Mize, Jeffery J; Anderson, David E

    2011-01-01

    SNS electrical systems have been operational for 4 years. System availability statistics and improvements are presented for AC electrical systems, DC and pulsed power supplies and klystron modulators.

  1. Tips for Improving Seed Planting Efficiency

    Treesearch

    R. Kasten Dumroese; David L. Wenny; Susan J. Morrison

    2002-01-01

    The efficiency of a precision seeder was improved by adding a mirror so employees could monitor seed levels and by marking seeds with brightly colored talc to quickly verify the accuracy of the machine.

  2. Root Cortical Senescence Improves Growth under Suboptimal Availability of N, P, and K1[OPEN

    PubMed Central

    Schneider, Hannah M.

    2017-01-01

    Root cortical senescence (RCS) in Triticeae reduces nutrient uptake, nutrient content, respiration, and radial hydraulic conductance of root tissue. We used the functional-structural model SimRoot to evaluate the functional implications of RCS in barley (Hordeum vulgare) under suboptimal nitrate, phosphorus, and potassium availability. The utility of RCS was evaluated using sensitivity analyses in contrasting nutrient regimes. At flowering (80 d), RCS increased simulated plant growth by up to 52%, 73%, and 41% in nitrate-, phosphorus-, and potassium-limiting conditions, respectively. Plants with RCS had reduced nutrient requirement of root tissue for optimal plant growth, reduced total cumulative cortical respiration, and increased total carbon reserves. Nutrient reallocation during RCS had a greater effect on simulated plant growth than reduced respiration or nutrient uptake. Under low nutrient availability, RCS had greater benefit in plants with fewer tillers. RCS had greater benefit in phenotypes with fewer lateral roots at low nitrate availability, but the opposite was true in low phosphorus or potassium availability. Additionally, RCS was quantified in field-grown barley in different nitrogen regimes. Field and virtual soil coring simulation results demonstrated that living cortical volume per root length (an indicator of RCS) decreased with depth in younger plants, while roots of older plants had very little living cortical volume per root length. RCS may be an adaptive trait for nutrient acquisition by reallocating nutrients from senescing tissue and secondarily by reducing root respiration. These simulated results suggest that RCS merits investigation as a breeding target for enhanced soil resource acquisition and edaphic stress tolerance. PMID:28667049

  3. 78 FR 24714 - Notice of Funds Availability Inviting Applications for the Federal-State Marketing Improvement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-26

    ... Agricultural Marketing Service Notice of Funds Availability Inviting Applications for the Federal-State Marketing Improvement Program (FSMIP) AGENCY: Agricultural Marketing Service, USDA. ACTION: Notice. SUMMARY: The Agricultural Marketing Service (AMS) announces the availability of approximately $1 million for...

  4. Foundational and translational research opportunities to improve plant health.

    PubMed

    Michelmore, Richard W; Coaker, Gitta; Bart, Rebecca; Beattie, Gwyn A; Bent, Andrew; Bruce, Toby; Cameron, Duncan; Dangl, Jeff; Dinesh-Kumar, Savithramma; Edwards, Robert; Eves-van den Akker, Sebastian; Gassmann, Walter; Greenberg, Jean; Harrison, Richard; He, Ping; Harvey, Jagger; Huffaker, Alisa; Hulbert, Scot; Innes, Roger; Jones, Jonathan D; Kaloshian, Isgouhi; Kamoun, Sophien; Katagiri, Fumiaki; Leach, Jan E; Ma, Wenbo; McDowell, John M; Medford, June; Meyers, Blake; Nelson, Rebecca; Oliver, Richard Peter; Qi, Yiping; Saunders, Diane; Shaw, Michael; Subudhi, Prasanta; Torrance, Leslie; Tyler, Brett M; Walsh, John

    2017-04-11

    This whitepaper reports the deliberations of a workshop focused on biotic challenges to plant health held in Washington, D.C. in September 2016. Ensuring health of food plants is critical to maintaining the quality and productivity of crops and for sustenance of the rapidly growing human population. There is a close linkage between food security and societal stability; however, global food security is threatened by the vulnerability of our agricultural systems to numerous pests, pathogens, weeds, and environmental stresses. These threats are aggravated by climate change, the globalization of agriculture, and an over-reliance on non-sustainable inputs. New analytical and computational technologies are providing unprecedented resolution at a variety of molecular, cellular, organismal, and population scales for crop plants as well as pathogens, pests, beneficial microbes, and weeds. It is now possible to both characterize useful or deleterious variation as well as precisely manipulate it. Data-driven, informed decisions based on knowledge of the variation of biotic challenges and of natural and synthetic variation in crop plants will enable deployment of durable interventions throughout the world. These should be integral, dynamic components of agricultural strategies for sustainable agriculture. Specific findings: ● Genetic improvement of crops is the most reliable, least expensive management strategy when suitable genetic variation is available. Nonetheless, some interventions have not proved durable due to the evolution and global dispersal of virulent pathogens and pests as well as herbicide-resistant weeds. ● Additional strategies are becoming essential as multiple fungicides, nematicides, and herbicides become ineffective due to the evolution of resistance and/or are phased out due to registration withdrawals. ● Strategies are needed that maximize the evolutionary hurdles for pathogens, pests, and weeds to overcome control measures. Interventions need to

  5. Plant growth-promoting bacteria and nitrate availability: impacts on root development and nitrate uptake.

    PubMed

    Mantelin, Sophie; Touraine, Bruno

    2004-01-01

    Plant growth-promoting bacteria (PGPB) and NO-3 availability both affect NO-3 uptake and root architecture. The presence of external NO-3 induces the expression of NO-3 transporter genes and elicits lateral root elongation in the part of the root system exposed to the NO-3 supply. By contrast, an increase in NO-3 supply leads to a higher plant N status (low N demand), which represses both the NO-3 transporters and lateral root development. The effects of PGPB on NO-3 uptake and root development are similar to those of low NO-3 availability (concomitant stimulation of NO-3 uptake rate and lateral root development). The mechanisms responsible for the localized and long-distance regulation of NO-3 uptake and root development by NO-3 availability are beginning to be elucidated. By contrast, the signalling and transduction pathways elicited by the rhizobacteria remain totally unknown. This review will compare the effects of NO-3 availability and PGPB on root morphogenesis and NO-3 uptake, in order to determine whether interactions exist between the NO-3-dependent and the PGPB-dependent regulatory pathways.

  6. RETRAN analyses for improving plant procedures and operator training

    SciTech Connect

    Broughton, T.G.; Trikouros, N.G.

    1983-05-01

    The technical quality of procedures governing integrated nuclear power plant operation is influenced by knowledge of system, component, and operator interactions. This knowledge includes, in part, operating plant data and realistic simulations of plant operation. This same information can be used to develop training materials for teaching plant dynamic response to plant operators and engineering staffs. Realistic simulations of plant performance have been used to supplement existing plant data or to provide data where none existed. The simulations may cover events with durations in hours and may be required to consider unique plant conditions including actual core physics conditions, valve leakage, and auxiliary steam loads. In addition, it should be possible for the simulation to account for operator interaction and to provide the information operators would have available through plant instrumentation. Simulations using the RETRAN computer code have been used in the development of procedures and training materials. Procedure applications have included development and validation of general control philosophy and establishment of specific test conditions and setpoints. Training applications include development of materials for teaching general plant response, specific plant response during tests, and analysis of plant performance.

  7. Improved Acquisition for System Sustainment: Availability-Based Importance Framework for Maintenance, Repair, and Overhaul Acquisition

    DTIC Science & Technology

    2015-06-30

    SPONSORED REPORT SERIES Improved Acquisition for System Sustainment: Availability- Based Importance Framework for Maintenance, Repair, and Overhaul...Sustainment: Availability- Based Importance Framework for Maintenance, Repair, and Overhaul Acquisition Prime Offeror Institution University of Oklahoma...Availability- Based Importance Measures . An effective defense strategy requires aircraft, among other weapons systems, to be available and ready for use when

  8. Root-zone plant available water estimation using the SMOS-derived soil water index

    NASA Astrophysics Data System (ADS)

    González-Zamora, Ángel; Sánchez, Nilda; Martínez-Fernández, José; Wagner, Wolfgang

    2016-10-01

    Currently, there are several space missions capable of measuring surface soil moisture, owing to the relevance of this variable in meteorology, hydrology and agriculture. However, the Plant Available Water (PAW), which in some fields of application could be more important than the soil moisture itself, cannot be directly measured by remote sensing. Considering the root zone as the first 50 cm of the soil, in this study, the PAW at 25 cm and 50 cm and integrated between 0 and 50 cm of soil depth was estimated using the surface soil moisture provided by the Soil Moisture Ocean Salinity (SMOS) mission. For this purpose, the Soil Water Index (SWI) has been used as a proxy of the root-zone soil moisture, involving the selection of an optimal T (Topt), which can be interpreted as a characteristic soil water travel time. In this research, several tests using the correlation coefficient (R), the Nash-Sutcliffe score (NS), several error estimators and bias as predictor metrics were applied to obtain the Topt, making a comprehensive study of the T parameter. After analyzing the results, some differences were found between the Topt obtained using R and NS as decision metrics, and that obtained using the errors and bias, but the SWI showed good results as an estimator of the root-zone soil moisture. This index showed good agreement, with an R between 0.60 and 0.88. The method was tested from January 2010 to December 2014, using the database of the Soil Moisture Measurements Stations Network of the University of Salamanca (REMEDHUS) in Spain. The PAW estimation showed good agreement with the in situ measurements, following closely the dry-downs and wetting-up events, with R ranging between 0.60 and 0.92, and error values lower than 0.05 m3m-3. A slight underestimation was observed for both the PAW and root-zone soil moisture at the different depths; this could be explained by the underestimation pattern observed with the SMOS L2 soil moisture product, in line with previous

  9. Reliability and availability analysis for robot subsystem in automotive assembly plant: a case study

    NASA Astrophysics Data System (ADS)

    Fudzin, A. F.; Majid, M. A. A.

    2015-12-01

    The automotive assembly plant in a manufacturing environment consists of conveying systems and robots. Robots with high reliability will ensure no interruption during production. This study is to analyze the individual robot reliability compared to reliability of robots subsystem in series configuration. Availability was computed based on individual robots breakdown data. Failures due to robots breakdown often occurred during the operations. Actual maintenance data for a period of seven years were used for the analysis. Incorporation of failures rate and mean time between failures yield the reliability computation with the assumption of constant failure rate. Result from the analysis based on 5000 operating hours indicated reliability of series configuration of robots in a subsystem decreased to 2.8% in comparison to 38% reliability of the individual robot with the lowest reliability. The calculated lowest availability of the robots is 99.41%. The robot with the lowest reliability and availability should be considered for replacement.

  10. Use of plants to evaluate the difference in available cadmium between soils

    SciTech Connect

    Kuboi, T.; Noguchi, A.

    1987-01-01

    A new method was proposed for assessing the difference in the capacity of soils to supply Cd to plants. The relation of tissue (tc) to soil (sc) Cd concentrations can be expressed as; log(tc) = ..cap alpha.. + ..beta.. log(sc), where ..cap alpha.. and ..beta.. are the regression coefficients. When the same plant is grown on another soil, the equation will change to; log(tc) = ..cap alpha..' + ..beta..' log(sc). Based on both equations, the relationship between sc' and sc becomes; log(sc') = (..cap alpha..-..cap alpha..)/..beta..' + (..beta../..beta..') log(sc). Set p = (..cap alpha..-..cap alpha..')/..beta..' and q = ..beta../..beta..', then the difference of Cd availability between two soils can be evaluated according to the values of p and q. The p and q values were determined among four treatments in which radish was grown on a sand soil and a silty loam soil at two pH levels. The values showed that the Cd present in the sand soil (pH 5.6) and the metal in the silty loam soil (pH 7.5) were the most and least available, respectively. It was therefore considered that the parameters p and q could be used as criteria for selecting an ideal extractant capable of removing the actually available Cd from soils.

  11. Hanford Waste Vitrification Plant technical background document for best available radionuclide control technology demonstration

    SciTech Connect

    Carpenter, A.B.; Skone, S.S.; Rodenhizer, D.G.; Marusich, M.V. )

    1990-10-01

    This report provides the background documentation to support applications for approval to construct and operate new radionuclide emission sources at the Hanford Waste Vitrification Plant (HWVP) near Richland, Washington. The HWVP is required to obtain permits under federal and state statutes for atmospheric discharges of radionuclides. Since these permits must be issued prior to construction of the facility, draft permit applications are being prepared, as well as documentation to support these permits. This report addresses the applicable requirements and demonstrates that the preferred design meets energy, environmental, and economic criteria for Best Available Radionuclide Control Technology (BARCT) at HWVP. 22 refs., 11 figs., 25 tabs.

  12. Plant roots use a patterning mechanism to position lateral root branches toward available water.

    PubMed

    Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

    2014-06-24

    The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root.

  13. Plant roots use a patterning mechanism to position lateral root branches toward available water

    PubMed Central

    Bao, Yun; Aggarwal, Pooja; Robbins, Neil E.; Sturrock, Craig J.; Thompson, Mark C.; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L.; Vernoux, Teva; Mooney, Sacha J.; Bennett, Malcolm J.; Dinneny, José R.

    2014-01-01

    The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 and PIN-FORMED 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root. PMID:24927545

  14. Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants

    PubMed Central

    Al-Wabel, Mohammad I.; Usman, Adel R.A.; El-Naggar, Ahmed H.; Aly, Anwar A.; Ibrahim, Hesham M.; Elmaghraby, Salem; Al-Omran, Abdulrasoul

    2014-01-01

    The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5–102% at 75% FC and 133–266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity. PMID:26150758

  15. Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants.

    PubMed

    Al-Wabel, Mohammad I; Usman, Adel R A; El-Naggar, Ahmed H; Aly, Anwar A; Ibrahim, Hesham M; Elmaghraby, Salem; Al-Omran, Abdulrasoul

    2015-07-01

    The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5-102% at 75% FC and 133-266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity.

  16. Effects of two contrasting hemiparasitic plant species on biomass production and nitrogen availability.

    PubMed

    Demey, Andreas; Ameloot, Els; Staelens, Jeroen; De Schrijver, An; Verstraeten, Gorik; Boeckx, Pascal; Hermy, Martin; Verheyen, Kris

    2013-09-01

    Hemiparasitic plants can substantially change plant community structure; the drainage of host resources has a direct negative effect on host biomass and, as a consequence, promotes non-host biomass production (parasitism pathway); on the other hand, hemiparasitic litter inputs can enhance nutrient cycling which may have an indirect positive effect on both host and non-host biomass production (litter pathway). We evaluated the net effect of both pathways on total shoot biomass (with and without the hemiparasite) and shoot biomass of graminoids, forbs and ericaceous shrubs using a removal experiment in three sites infested with the annual Rhinanthus angustifolius, and three sites infested with the biennial Pedicularis sylvatica. We addressed the potential importance of litter effects by determination of litter quantity and quality, as well as modeling N release during decomposition. In the second year after removing the hemiparasites, total plant biomass at Rhinanthus sites was 24 % higher in weeded plots than in control plots, while weeding had no significant effect at Pedicularis sites. The increase in total biomass following Rhinanthus removal was mainly due to a higher biomass of graminoids. The amount of litter produced by Rhinanthus was only half of that produced by Pedicularis; N contents were similar. The amount of N in the litter was 9 and 30 % of the amount removed by mowing for Rhinanthus and Pedicularis sites, respectively. Within 2 months, about 45 % of the N in both hemiparasitic litter types was released by decomposition. Our results suggest that in addition to the suppression of host biomass due to parasitism, positive litter feedbacks on host and non-host biomass-via an increase in nutrient availability-also affect plant community structure. We propose that, depending on the particular hemiparasite and/or site conditions, these positive litter feedbacks on shoot biomass can compensate for the negative effect of parasitism.

  17. 76 FR 37771 - Monsanto Co.; Availability of Petition, Plant Pest Risk Assessment, and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There... genetic engineering that are plant pests or that there is reason to believe are plant pests. Such...

  18. 77 FR 41366 - Syngenta Biotechnology, Inc.; Availability of Petition, Plant Pest Risk Assessment, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests... environment) of organisms and products altered or produced through genetic engineering that are plant pests or...

  19. 77 FR 41363 - BASF Plant Science, LP; Availability of Petition for Determination of Nonregulated Status of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ..., ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or... produced through genetic engineering that are plant pests or that there is reason to believe are plant...

  20. 76 FR 27301 - Syngenta Biotechnology, Inc.; Availability of Petition, Plant Pest Risk Assessment, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There... genetic engineering that are plant pests or that there is reason to believe are plant pests. Such...

  1. 78 FR 67100 - Okanagan Specialty Fruits, Inc.; Availability of Plant Pest Risk Assessment and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ..., ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or... produced through genetic engineering that are plant pests or that there is reason to believe are plant...

  2. Plant-available and water-soluble phosphorus in soils amended with separated manure solids.

    PubMed

    Gasser, M-O; Chantigny, M H; Angers, D A; Bittman, S; Buckley, K E; Rochette, P; Massé, D

    2012-01-01

    Physical, chemical, or biological treatment of animal liquid manure generally produces a dry-matter rich fraction (DMF) that contains most of the initial phosphorus (P). Our objective was to assess the solubility and plant availability of P from various DMFs as a function of soil P status. Eight different DMFs were obtained from liquid swine (LSM) and dairy cattle (LDC) manures treated by natural decantation, anaerobic digestion, chemical flocculation, composting, or mechanical separation. The DMFs were compared with mineral P fertilizer in a pot experiment with oat ( L.) grown in four soils with varied P-fixing capacities and P saturation levels. The DMFs were added at a rate of 50 mg P kg soil and incubated 14 d before seeding. Soil water-extractable P (P) at all water:soil extraction ratios (2:1, 20:1, and 200:1) was slightly higher when DMFs were derived from LDC rather than LSM. Soil P at the 2:1 ratio was lower with anaerobically digested LSM. At the 2:1 extraction ratio, DMF P was less soluble than mineral P as P saturation in soils increased. In soils with a lower P-fixing capacity, DMF P appeared less water soluble than mineral P under 20:1 and 200:1 extraction ratios. After 72 d of plant growth, DMFs produced yields comparable to mineral P fertilizer. Although the plant availability of P from DMFs was comparable to mineral P fertilizer, P from DMFs could be less vulnerable to leaching or runoff losses in soils with a high P saturation level or low P-fixing capacity. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Nitrogen availability alters the expression of carnivory in the northern pitcher plant, Sarracenia purpurea.

    PubMed

    Ellison, Aaron M; Gotelli, Nicholas J

    2002-04-02

    Atmospheric transport and deposition of nutrients, especially nitrogen, is a global environmental problem with well-documented consequences for ecosystem dynamics. However, monitoring nitrogen deposition is relatively expensive, monitoring stations are widely spaced, and estimates and predicted impacts of nitrogen deposition are currently derived from spatial modeling and interpolation of limited data. Ombrotrophic ("rain-fed") bogs are nutrient-poor ecosystems that are especially sensitive to increasing nutrient input, and carnivorous plants, which are characteristic of these widespread ecosystem types, may be especially sensitive indicators of N deposition. Botanical carnivory is thought to have evolved in nutrient-poor and well-lit habitats such as bogs because the marginal benefits accruing from carnivory exceed the marginal photosynthetic costs associated with the maintenance of carnivorous organs. However, the production of carnivorous organs can be a phenotypically plastic trait. The northern pitcher plant, Sarracenia purpurea, produces leaves specialized for prey capture and nutrient uptake (pitchers) and leaves that are more efficient at photosynthesis (phyllodia). We hypothesized that relative allocation to these two types of leaves reflects ambient nitrogen availability. We manipulated nutrient availability to plants with leaf enrichment and whole-plot fertilization experiments. Increased nitrogen, but not phosphorus, reduced production of pitchers relative to phyllodia; this result provided empirical support for the cost-benefit model of the evolution of botanical carnivory. Because this phenotypic shift in leaf production occurs in ecological time, our results suggest that S. purpurea could be a reliable and inexpensive biological indicator of nitrogen deposition rates. This suggestion is supported by field observations across a geographic gradient of nitrogen deposition.

  4. Dynamic Response of Plant Chlorophyll Fluorescence to Light, Water and Nutrient Availability

    NASA Astrophysics Data System (ADS)

    Cendrero Mateo, M. D. P.; Moran, S. M.; Porcar-Castell, A.; Carmo-Silva, A. E.; Papuga, S. A.; Matveeva, M.; Wieneke, S.; Rascher, U.

    2014-12-01

    Photosynthesis is the most important exchange process of CO2 between the atmosphere and the land-surface. Spatial and temporal patterns of photosynthesis depend on dynamic plant-specific adaptation strategies to highly variable environmental conditions e.g. light, water, and nutrient availability. Chlorophyll fluorescence (ChF) has been proposed as a direct indicator of photosynthesis, and several studies have demonstrated its relationship with vegetation functioning at leaf and canopy level. In this study, two overarching questions about ChF were addressed: Q1) How water, nutrient and ambient light conditions determine the relationships between photosynthesis and ChF? Which is the optimum irradiance level for detecting water and nutrient deficit conditions with ChF?; Q2) What is the seasonal relationship between photosynthesis and ChF when nitrogen is the limiting factor? The results of this study indicated that when the differences between treatments (water or nitrogen) drive the relationship between photosynthesis and ChF, ChF has a direct relationship with photosynthesis. This study demonstrates that the light level at which plants were grown was optimum for detecting water and nutrient deficit with ChF. Further, the seasonal relation between photosynthesis and ChF with nitrogen stress was not a simple linear function due to the complex physiological relation between photosynthesis and ChF. Our study showed that at times in the season when nitrogen was sufficient and photosynthesis was highest, ChF decreased because these two processes compete for available energy. The results from this study demonstrated that ChF is a reliable indicator of plant stress and has great potential as a tool for better understand where, when, and how CO2 is exchanged between the land and atmosphere.

  5. Effects of sewage sludge biochar on plant metal availability after application to a Mediterranean soil.

    PubMed

    Méndez, A; Gómez, A; Paz-Ferreiro, J; Gascó, G

    2012-11-01

    Pyrolytic conversion of sewage sludge into biochar could be a sustainable management option for Mediterranean agricultural soils. The aim of this work is to evaluate the effects of biochar from sewage sludge pyrolysis on soil properties; heavy metals solubility and bioavailability in a Mediterranean agricultural soil and compared with those of raw sewage sludge. Biochar (B) was prepared by pyrolysis of selected sewage sludge (SL) at 500°C. The pyrolysis process decreased the plant-available of Cu, Ni, Zn and Pb, the mobile forms of Cu, Ni, Zn, Cd and Pb and also the risk of leaching of Cu, Ni, Zn and Cd. A selected Mediterranean soil was amended with SL and B at two different rates in mass: 4% and 8%. The incubation experiment (200 d) was conducted in order to study carbon mineralization and trace metal solubility and bioavailability of these treatments. Both types of amendments increased soil respiration with respect to the control soil. The increase was lower in the case of B than when SL was directly added. Metals mobility was studied in soil after the incubation and it can be established that the risk of leaching of Cu, Ni and Zn were lower in the soil treated with biochar that in sewage sludge treatment. Biochar amended samples also reduced plant availability of Ni, Zn, Cd and Pb when compared to sewage sludge amended samples. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Spatial distribution of understory plants along gradients of water and light availability

    SciTech Connect

    Holmgren, M.; Huston, M.A.; Quiles, J.; Warner, S. )

    1994-06-01

    We measured the percent cover, stem densities, and heights of understory plant species in 72 3 [times] 3m plots on a southeast-facing slope of mature mixed oak forest. The 80 [times] 240 m site is intensively instrumented for monitoring soil water content using the Time Domain Reflectometry method as part of the Throughfall Displacement Experiment on Walker Branch Watershed. We estimated canopy openness in each of the plots using hemispherical photographs. The goal of the research was to determined if the spatial distribution of understory community structure was consistent with hypothesized limitations imposed by water availability on plant responses to light. We measured the natural patterns of size, abundance, and survival of seedlings of fourteen tree species under a range of light and soil water availability. Seedling densities ranged from 4 individuals per meter square under dry, low light conditions, to 27 per meter square under the high light, high moisture conditions. Red maple comprised about two thirds of the total number of seedlings. Several distinct types of responses can be identified from three-dimensional graphs of size, abundance, or survival in relation to light and water.

  7. The effects of natural enemies, competition, and host plant water availability on an aphid population.

    PubMed

    Morris, William F

    1992-06-01

    I used a factorial experiment repeated in two years to assess the relative effects of natural enemy attack, interspecific competition, and water availability to the host plant, and of interactions among these factors, on the population dynamics of the aphid Aphis varians feeding on fireweed (Epilobium angustifolium). The impact of a suite of coccinellid and syrphid predators emerged as the predominant factor affecting the success of aphid colonies: colonies protected from natural enemies grew in size at a rate of ten percent per day, were only one tenth as likely to go extinct, and produced over ten times more dispersing alates. In contrast, I found only minor effects of removing flea beetles, the most abundant herbivore with which A. varians colonies cohabit fireweed stems, and of supplementing water availability to fireweed host plants, in spite of a significant effect of watering frequency on aphid growth in the green-house. There was no evidence of significant two- or three-way interactions among factors. Hence, despite the potential complexity of the food web in which it is embedded, the dynamics of A. varians appears to be driven predominantly by a single factor, i.e. interactions with natural enemies.

  8. Plant toxicity studies made publicly available by EPA and the TSCA Interagency Testing Committee

    SciTech Connect

    Walker, J.D.

    1994-12-31

    The purpose of this presentation is to briefly describe the ITC, describe the Toxic Substances Control Act (TSCA) Test Submissions (TSCATS) database and how the EPA makes unpublished health and safety studies publicly available through TSCATS as a result of ITC testing recommendations and other activities and to describe some of the unpublished plant toxicity studies that are available tin TSCATS. In 1976, under section 4(e) of the Toxic Substances Control Act (TSCA), the US Congress created the ITC to implement the initial phases of testing TSCA-regulable chemicals. Congress directed the ITC to: (1) make testing decisions on about 70,000 chemicals, (2) develop the TSCA Section 4(e) Priority Testing List, (3) coordinate chemical testing and (4) revise the List at least every six months. The creation, structure, functions and contributions of the ITC from 1977 to 1992 have been previously described. TSCATS is an EPA database. It is an online pointer file that identifies all the unpublished studies that have been submitted to EPA under TSCA sections 4 and 8 and as For Your Information studies. Most of the studies in TSCATS were submitted by manufacturers of chemicals that ITC has added to the Priority Testing List because EPA has published Federal Register notices requesting that manufacturers of ITC chemicals submit unpublished data under TSCA section 8 or conduct testing and submit the data that were developed under TSCA section 4. Data from plant toxicity studies indexed in TSCATS will be presented.

  9. Responses of Reclamation Plants to High Root Zone pH: Effects of Phosphorus and Calcium Availability.

    PubMed

    Zhang, Wenqing; Zwiazek, Janusz J

    2016-09-01

    Low phosphorus (P) availability and high pH inhibit plant growth in calcareous soils and some oil sands reclamation sites in northeastern Alberta, Canada. In this study, we used a split-root hydroponic setup to test the effects of supplemental P with different calcium (Ca) concentrations and root-zone pH conditions on the growth and physiological response of trees commonly found in the region: paper birch ( Marsh.), trembling aspen ( Michx.), green alder [ (Chaix) DC.], and black spruce [ (Mill.) Britton, Sterns & Poggenb.] seedlings. Plant roots were divided and treated with different combinations of P (0.5 and 15 mmol L), Ca (2 and 50 mmol L), and pH (5.0 and 9.0) for 6 wk. After that time, we measured seedling height, net photosynthesis and transpiration rates, and the concentration of chlorophyll and different elements in the leaves. Plant responses varied between species; black spruce was most resistant to high pH and high Ca concentrations. We did not find any strong beneficial effects of adding P to plants subjected to high root zone pH and high Ca concentration. However, exposure of part of the root system to low pH alleviated the effects of high pH, likely through the improved supply of micronutrients. Because pH conditions are often not uniform in disturbed sites and reclamation soils, our findings may help improve potential reclamation and phytoremediation strategies for the oil sands, bauxite, and coal-combustion residue utilization industries. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  10. Soil nitrogen availability and plant genotype modify the nutrition strategies of M. truncatula and the associated rhizosphere microbial communities.

    PubMed

    Zancarini, Anouk; Mougel, Christophe; Voisin, Anne-Sophie; Prudent, Marion; Salon, Christophe; Munier-Jolain, Nathalie

    2012-01-01

    Plant and soil types are usually considered as the two main drivers of the rhizosphere microbial communities. The aim of this work was to study the effect of both N availability and plant genotype on the plant associated rhizosphere microbial communities, in relation to the nutritional strategies of the plant-microbe interactions, for six contrasted Medicago truncatula genotypes. The plants were provided with two different nutrient solutions varying in their nitrate concentrations (0 mM and 10 mM). First, the influence of both nitrogen availability and Medicago truncatula genotype on the genetic structure of the soil bacterial and fungal communities was determined by DNA fingerprint using Automated Ribosomal Intergenic Spacer Analysis (ARISA). Secondly, the different nutritional strategies of the plant-microbe interactions were evaluated using an ecophysiological framework. We observed that nitrogen availability affected rhizosphere bacterial communities only in presence of the plant. Furthermore, we showed that the influence of nitrogen availability on rhizosphere bacterial communities was dependent on the different genotypes of Medicago truncatula. Finally, the nutritional strategies of the plant varied greatly in response to a modification of nitrogen availability. A new conceptual framework was thus developed to study plant-microbe interactions. This framework led to the identification of three contrasted structural and functional adaptive responses of plant-microbe interactions to nitrogen availability.

  11. Developing Predictive Maintenance Expertise to Improve Plant Equipment Reliability

    SciTech Connect

    Wurzbach, Richard N.

    2002-07-01

    On-line equipment condition monitoring is a critical component of the world-class production and safety histories of many successful nuclear plant operators. From addressing availability and operability concerns of nuclear safety-related equipment to increasing profitability through support system reliability and reduced maintenance costs, Predictive Maintenance programs have increasingly become a vital contribution to the maintenance and operation decisions of nuclear facilities. In recent years, significant advancements have been made in the quality and portability of many of the instruments being used, and software improvements have been made as well. However, the single most influential component of the success of these programs is the impact of a trained and experienced team of personnel putting this technology to work. Changes in the nature of the power generation industry brought on by competition, mergers, and acquisitions, has taken the historically stable personnel environment of power generation and created a very dynamic situation. As a result, many facilities have seen a significant turnover in personnel in key positions, including predictive maintenance personnel. It has become the challenge for many nuclear operators to maintain the consistent contribution of quality data and information from predictive maintenance that has become important in the overall equipment decision process. These challenges can be met through the implementation of quality training to predictive maintenance personnel and regular updating and re-certification of key technology holders. The use of data management tools and services aid in the sharing of information across sites within an operating company, and with experts who can contribute value-added data management and analysis. The overall effectiveness of predictive maintenance programs can be improved through the incorporation of newly developed comprehensive technology training courses. These courses address the use of

  12. Interacting TCP and NLP transcription factors control plant responses to nitrate availability.

    PubMed

    Guan, Peizhu; Ripoll, Juan-José; Wang, Renhou; Vuong, Lam; Bailey-Steinitz, Lindsay J; Ye, Dening; Crawford, Nigel M

    2017-02-28

    Plants have evolved adaptive strategies that involve transcriptional networks to cope with and survive environmental challenges. Key transcriptional regulators that mediate responses to environmental fluctuations in nitrate have been identified; however, little is known about how these regulators interact to orchestrate nitrogen (N) responses and cell-cycle regulation. Here we report that teosinte branched1/cycloidea/proliferating cell factor1-20 (TCP20) and NIN-like protein (NLP) transcription factors NLP6 and NLP7, which act as activators of nitrate assimilatory genes, bind to adjacent sites in the upstream promoter region of the nitrate reductase gene, NIA1, and physically interact under continuous nitrate and N-starvation conditions. Regions of these proteins necessary for these interactions were found to include the type I/II Phox and Bem1p (PB1) domains of NLP6&7, a protein-interaction module conserved in animals for nutrient signaling, and the histidine- and glutamine-rich domain of TCP20, which is conserved across plant species. Under N starvation, TCP20-NLP6&7 heterodimers accumulate in the nucleus, and this coincides with TCP20 and NLP6&7-dependent up-regulation of nitrate assimilation and signaling genes and down-regulation of the G2/M cell-cycle marker gene, CYCB1;1 TCP20 and NLP6&7 also support root meristem growth under N starvation. These findings provide insights into how plants coordinate responses to nitrate availability, linking nitrate assimilation and signaling with cell-cycle progression.

  13. Plant Growth Environments with Programmable Relative Humidity and Homogeneous Nutrient Availability.

    PubMed

    Lind, Kara R; Lee, Nigel; Sizmur, Tom; Siemianowski, Oskar; Van Bruggen, Shawn; Ganapathysubramaniam, Baskar; Cademartiri, Ludovico

    2016-01-01

    We describe the design, characterization, and use of "programmable", sterile growth environments for individual (or small sets of) plants. The specific relative humidities and nutrient availability experienced by the plant is established (RH between 15% and 95%; nutrient concentration as desired) during the setup of the growth environment, which takes about 5 minutes and <1$ in disposable cost. These systems maintain these environmental parameters constant for at least 14 days with minimal intervention (one minute every two days). The design is composed entirely of off-the-shelf components (e.g., LEGO® bricks) and is characterized by (i) a separation of root and shoot environment (which is physiologically relevant and facilitates imposing specific conditions on the root system, e.g., darkness), (ii) the development of the root system on a flat surface, where the root enjoys constant contact with nutrient solution and air, (iii) a compatibility with root phenotyping. We demonstrate phenotyping by characterizing root systems of Brassica rapa plants growing in different relative humidities (55%, 75%, and 95%). While most phenotypes were found to be sensitive to these environmental changes, a phenotype tightly associated with root system topology-the size distribution of the areas encircled by roots-appeared to be remarkably and counterintuitively insensitive to humidity changes. These setups combine many of the advantages of hydroponics conditions (e.g., root phenotyping, complete control over nutrient composition, scalability) and soil conditions (e.g., aeration of roots, shading of roots), while being comparable in cost and setup time to Magenta® boxes.

  14. Plant Growth Environments with Programmable Relative Humidity and Homogeneous Nutrient Availability

    PubMed Central

    Lind, Kara R.; Lee, Nigel; Sizmur, Tom; Siemianowski, Oskar; Van Bruggen, Shawn; Ganapathysubramaniam, Baskar

    2016-01-01

    We describe the design, characterization, and use of “programmable”, sterile growth environments for individual (or small sets of) plants. The specific relative humidities and nutrient availability experienced by the plant is established (RH between 15% and 95%; nutrient concentration as desired) during the setup of the growth environment, which takes about 5 minutes and <1$ in disposable cost. These systems maintain these environmental parameters constant for at least 14 days with minimal intervention (one minute every two days). The design is composed entirely of off-the-shelf components (e.g., LEGO® bricks) and is characterized by (i) a separation of root and shoot environment (which is physiologically relevant and facilitates imposing specific conditions on the root system, e.g., darkness), (ii) the development of the root system on a flat surface, where the root enjoys constant contact with nutrient solution and air, (iii) a compatibility with root phenotyping. We demonstrate phenotyping by characterizing root systems of Brassica rapa plants growing in different relative humidities (55%, 75%, and 95%). While most phenotypes were found to be sensitive to these environmental changes, a phenotype tightly associated with root system topology–the size distribution of the areas encircled by roots–appeared to be remarkably and counterintuitively insensitive to humidity changes. These setups combine many of the advantages of hydroponics conditions (e.g., root phenotyping, complete control over nutrient composition, scalability) and soil conditions (e.g., aeration of roots, shading of roots), while being comparable in cost and setup time to Magenta® boxes. PMID:27304431

  15. Interlaboratory validation of the Mehlich 3 method for extraction of plant-available phosphorus.

    PubMed

    Zhang, Hailin; Kaiuki, Solomon; Schroder, Jackie L; Payton, Mark E; Focht, Charlie

    2009-01-01

    The Mehlich 3 (M3) method is widely used for extraction of plant-available phosphorus (P) from soil over a wide range of pH values. The method is also used by many laboratories to determine multiple plant-available nutrients simultaneously. However, this method has not been statistically validated within and among laboratories. The objective of this study was to determine the repeatability (within-laboratory performance) and reproducibility (among-laboratories performance) of the M3 method by using a wide variety of soils. An in-house homogeneity test was conducted for 10 soils. Three replicates of each of the 10 soils were sent to 26 domestic and international laboratories primarily for P analysis. Samples were scooped, weighed, or both scooped and weighed for extraction. The P in extracts was quantified by the participating laboratories by using inductively coupled plasma-atomic emission spectrometry (ICP-AES) or colorimetrically. For the scooped samples analyzed colorimetrically, the repeatability relative standard deviation (RSDr) ranged from 2.07 to 12.1%; the RSDr ranged from 2.2 to 21.4% for the scooped samples analyzed by ICP-AES. For the weighed samples analyzed colormetrically, the RSDr values were 1.09-9.34%, and for the weighed samples analyzed by ICP-AES, they were 1.70-5.76%. For the reproducibility data, the RSDR values ranged from 6.85 to 50.8% for the scooped-colorimetry category, from 6.95 to 73.9% for the scooped-ICP-AES category, from 7.19 to 42.6% for the weighed-colorimetry category, and from 5.29 to 35.9% for the weighed-ICP-AES category. The greatest RSD values were associated with the Susitna soil, which had the smallest concentration of extractable P. Because of the relatively small concentration of P in this soil, the laboratories were attempting to measure solution concentrations that were close to the detection limits. The Horwitz ratios (HorRat) were also used to evaluate the repeatability, HorRat(r), and reproducibility, Hor

  16. Soil tests for predicting plant available phosphorus in newly reclaimed alkaline minespoil

    SciTech Connect

    Dancer, W.S.

    1984-01-01

    Four selected soil tests (Olson's bicarbonate, Bray P-1, Bray P-2, and a modified Bray P-1 test) were compared over a four year period as methods for predicting plant available-P in a slightly alkaline (pH 7.25) minespoil from a west-central coal field in Illinois. Phosphorus recovery by hybrid corn, measured both greenhouse and field conditions, showed that the minespoil was extremely P deficient. Extractable Olson's bicarbonate P and standard Bray P-1 phosphorus were highly correlated with total-P recovery by corn, with respective coefficients of r=0.973 and r=0.957 in the greenhouse; and r=0.998 and r=0.983 respectively, under field conditions. Consistent Mitscherlich-Bray proportionality constants were calculated from corn grain yields under field conditions in three of four years, after adjustments for annual differences in plant population density. Minespoil was found to require about twice as much extractable-P (about 40 mg/kg Olson-bicarbonate or Bray P-1) as topsoil to support maximum corn productivity. It was estimated that more than 500 kg/ha fertilizer-P will be required to achieve maximum corn grain production in spoil.

  17. The non-native plant Rosa multiflora expresses shade avoidance traits under low light availability.

    PubMed

    Dlugos, Daniel M; Collins, Hilary; Bartelme, Elise M; Drenovsky, Rebecca E

    2015-08-01

    • Shade tolerance is a key trait promoting invasive plant performance in forest interiors. Rosa multiflora is a problematic invasive shrub in the northeastern United States, occurring in edge habitats and encroaching into forests. Our objective was to evaluate the shade tolerance of R. multiflora to assess how ecophysiological traits may facilitate its spread into forest interiors.• In the field, we documented shrub and seed bank density, fecundity, phenology, and seasonal photosynthetic rates of R. multiflora in contrasting light environments. In the greenhouse, we exposed seedlings to simulated canopy treatments by altering spectral quantity and quality, mimicking habitats ranging from open fields to forest interiors.• In the field, shrub density and fecundity of R. multiflora sharply increased with light availability. However, no differences were observed between forest edge and interior seed banks. Rosa multiflora initiated leaf growth earlier and retained leaves longer than canopy vegetation and tended to have higher photosynthetic rates in spring and fall. In the greenhouse, plants displayed shade-avoidance traits, decreasing relative growth rate and reducing branching, while increasing elongation and showing no change in light response curve parameters.• In deciduous forest understories, R. multiflora appears to make use of a lengthened growing season in spring and fall, and therefore, substantial growth and spread through intact forests appears dependent on canopy gaps. Management should focus on reducing edge populations to reduce spread into the interior and on monitoring newly created canopy gaps. © 2015 Botanical Society of America, Inc.

  18. MicroRNA-based biotechnology for plant improvement.

    PubMed

    Zhang, Baohong; Wang, Qinglian

    2015-01-01

    MicroRNAs (miRNAs) are an extensive class of newly discovered endogenous small RNAs, which negatively regulate gene expression at the post-transcription levels. As the application of next-generation deep sequencing and advanced bioinformatics, the miRNA-related study has been expended to non-model plant species and the number of identified miRNAs has dramatically increased in the past years. miRNAs play a critical role in almost all biological and metabolic processes, and provide a unique strategy for plant improvement. Here, we first briefly review the discovery, history, and biogenesis of miRNAs, then focus more on the application of miRNAs on plant breeding and the future directions. Increased plant biomass through controlling plant development and phase change has been one achievement for miRNA-based biotechnology; plant tolerance to abiotic and biotic stress was also significantly enhanced by regulating the expression of an individual miRNA. Both endogenous and artificial miRNAs may serve as important tools for plant improvement. © 2014 Wiley Periodicals, Inc.

  19. Engineering rhizosphere hydraulics: pathways to improve plant adaptation to drought

    NASA Astrophysics Data System (ADS)

    Ahmed, Mutez; Zarebanadkouki, Mohsen; Ahmadi, Katayoun; Kroener, Eva; Kostka, Stanley; Carminati, Andrea

    2017-04-01

    rhizosphere reproduced well the experimental observations. Rhizoligands increase the rhizosphere wetting kinetics and decrease the maximum swelling of mucilage. As a consequence, root rehydration upon irrigation is faster, a larger volume of water is available to the plant and this water is used more slowly. This slower water consumption would allow the plant to stay turgid over a prolonged dying period. We propose that by managing the hydraulic properties of the rhizosphere, we can improve plants adaptation to drought.

  20. Effects of plant availability on population size and dynamics of an insect community: diamondback moth and two of its parasitoids.

    PubMed

    Soufbaf, M; Fathipour, Y; Karimzadeh, J; Zalucki, M P

    2014-08-01

    To understand the effect of plant availability/structure on the population size and dynamics of insects, a specialist herbivore in the presence of two of its parasitoids was studied in four replicated time-series experiments with high and low plant availabilities; under the latter condition, the herbivore suffered from some periods of resource limitation (starvation) and little plant-related structural refuges. Population dynamics of the parasitoid Cotesia vestalis was governed mainly by the delayed density-dependent process under both plant setups. The parasitoid, Diadegma semiclausum, under different plant availabilities and different coexistence situations (either +competitor or -competitor) showed dynamics patterns that were governed mainly by the delayed density process (significant lags at weeks 2-4). Both the competing parasitoids did not experience beneficial or costly interferences from each other in terms of their own population size when the plant resource was limited. Variation in the Plutella xylostella population under limited plant availability is higher than that under the other plant setup. For both parasitoids, under limited plant setup, the extinction risk was lower when parasitoids were engaged in competition, while under the unlimited plant setup, the mentioned risk was higher when parasitoids competed. In this situation, parasitoids suffered from two forces, competition and higher escaped hosts.

  1. Antibacterial activity of commercially available plant-derived essential oils against oral pathogenic bacteria.

    PubMed

    Bardají, D K R; Reis, E B; Medeiros, T C T; Lucarini, R; Crotti, A E M; Martins, C H G

    2016-01-01

    This work investigated the antibacterial activity of 15 commercially available plant-derived essential oils (EOs) against a panel of oral pathogens. The broth microdilution method afforded the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the assayed EOs. The EO obtained from Cinnamomum zeylanicum (Lauraceae) (CZ-EO) displayed moderate activity against Fusobacterium nucleatum (MIC and MBC = 125 μg/mL), Actinomyces naeslundii (MIC and MBC = 125 μg/mL), Prevotella nigrescens (MIC and MBC = 125 μg/mL) and Streptococcus mutans (MIC = 200 μg/mL; MBC = 400 μg/mL). (Z)-isosafrole (85.3%) was the main chemical component of this oil. We did not detect cinnamaldehyde, previously described as the major constituent of CZ-EO, in specimens collected in other countries.

  2. Maize somatic embryogenesis: recent features to improve plant regeneration.

    PubMed

    Garrocho-Villegas, Verónica; de Jesús-Olivera, María Teresa; Quintanar, Estela Sánchez

    2012-01-01

    Plant regeneration capacity is maintained through the life of a plant by the stem cell niche present in the meristems. Stem cells are capable of differentiating into any plant organ, allowing propagation of new plants by different techniques. Among them, somatic embryogenesis is a widely used technique characterized by a complex process that involves coordinated expression of genes, mediated by the influence of specific hormones, nutrients, stress, and/or environmental signals. This tool is particularly relevant in the propagation of genetically improved crops. The intrinsic embryogenic potential of the explant used as starting material for plant in vitro cultures varies depending on the genotype of each plant species. Particularly in maize, the regeneration capacity is lost during the course of tissue maturation, since embryogenic callus (E) is almost exclusively obtained from immature zygotic embryos. In this chapter, the latest advances in the literature for maize somatic embryogenesis process are reviewed. Further, a detailed procedure for maize plant regeneration from E callus is described. The callus obtained from immature zygotic embryos is capable to generate somatic embryos that germinate and develop into fertile normal plants.

  3. Innovative applications of technology for nuclear power plant productivity improvements

    SciTech Connect

    Naser, J. A.

    2012-07-01

    The nuclear power industry in several countries is concerned about the ability to maintain high plant performance levels due to aging and obsolescence, knowledge drain, fewer plant staff, and new requirements and commitments. Current plant operations are labor-intensive due to the vast number of operational and support activities required by commonly used technology in most plants. These concerns increase as plants extend their operating life. In addition, there is the goal to further improve performance while reducing human errors and increasingly focus on reducing operations and maintenance costs. New plants are expected to perform more productively than current plants. In order to achieve and increase high productivity, it is necessary to look at innovative applications of modern technologies and new concepts of operation. The Electric Power Research Inst. is exploring and demonstrating modern technologies that enable cost-effectively maintaining current performance levels and shifts to even higher performance levels, as well as provide tools for high performance in new plants. Several modern technologies being explored can provide multiple benefits for a wide range of applications. Examples of these technologies include simulation, visualization, automation, human cognitive engineering, and information and communications technologies. Some applications using modern technologies are described. (authors)

  4. Chromium fractionation and plant availability in tannery-sludge amended soil

    NASA Astrophysics Data System (ADS)

    Allué, Josep; Moya Garcés, Alba; Bech, Jaume; Barceló, Juan; Poschenrieder, Charlotte

    2013-04-01

    The leather industry represents an important economic sector in both developed and developing countries. Chromium tanning is the major process used to obtain high quality leather. Within the REACH regulation the use of Cr, especially CrVI, in the tanning process is under discussion in Europe. High Cr concentration in shoes and other Cr-tanned leather products can cause contact dermatitis in sensitive population. Moreover, the high Cr concentration is the major limiting factor for the use of tannery sludge as a source of organic matter in agricultural soils. Interest in Cr, however is not limited to its potential toxic effects. Chromium III is used as a dietary supplement because there are reports, but also controversy, about the positive effects of Cr III in glucose tolerance and type-2 diabetes. Adequate intake levels for Cr by the diet have been established between 25 and 35 µg/day for adult females and males, respectively. Sufficient supply of Cr III by the diet is preferable to the use of CrIII-salt based dietary supplements. The objective of the present work was to investigate whether Cr from tannery sludge-amended soil is available to Trigonella foenum-graecum plants, a plant used both as a spice and as a medicinal herb, because of its hypoglucemic effects. For this purpose clay loam soil (pH 7.8) was sieved (2mm) and thoroughly mixed with tannery sludge from a depuration station (Igualadina Depuració i Recuperació S.L., Igualada, Barcelona, Spain). The sludge had a Cr concentration of 6,034mg kg-1 and a 0.73 % of NH4-nitrogen. All the Cr was in the form of CrIII. Three treatments were disposed. Control soil receiving no sludge, a 60 mg kg-1 Cr treatment (10 g fresh sludge kg-1 soil) and a 120 mg kg-1 Cr treatment (20 g fresh sludge kg-1 soil). Control soil and the soil treated with 10g kg-1 sludge received NPK fertilizer in the form of ammonium sulfate, superfosfate, and KCl to rise the N,P, and K concentrations to similar levels to those achieved in the

  5. Availability of 15N from pioneer herbaceous plants to pine seedlings in reclaimed burnt soils.

    PubMed

    González-Prieto, S J; Villar, M C; Carballas, T

    2008-09-01

    A pot experiment was used to assess N uptake by pine seedlings during 2 years on a burnt soil to which was added (15)N-labelled ryegrass, obtained from a (15)N-enriched sample of this soil after a fire. The nitrogen concentration in needles, stems and roots of seedlings decreased significantly from the first to the second growing period (from 2.55, 1.30 and 2.19% to 1.19, 0.47 and 1.00%, respectively), with needles accounting for 53-58% of the pine-N. At the end of the experiment, 98.87 +/- 1.12% of the added ryegrass-(15)N was recovered: two-thirds in the soil organic N pool and one-third in the pine seedlings. Therefore, the post-fire pulse of inorganic-N, which was successfully kept in the burnt soil-plant system through its uptake by the pioneer species, is available for trees in the medium term. Pine seedlings assimilated 16.4% and 16.9% of the added ryegrass-(15)N in the first and second year, respectively. This result contrasts with the usual yearly decrease of added N uptake by plants; a possible explanation is the transient increase of available N in burnt soils that would have modified the mineralization pattern of the (15)N-labelled phytomass. The pine-N derived from the ryegrass-N decreased from 4.05% in the first year to 2.53% in the second one, with 3.10% being the 2-year weighed average. In addition to the direct contribution of ryegrass to pine-N nutrition reflected by these figures, the rapid post-fire establishment of a herbaceous cover on the burnt soil also provides important indirect benefits for tree nutrition by reducing organic- and inorganic-N losses. Copyright (c) 2008 John Wiley & Sons, Ltd.

  6. Combined effects of climate, resource availability, and plant traits on biomass produced in a Mediterranean rangeland.

    PubMed

    Chollet, Simon; Rambal, Serge; Fayolle, Adeline; Hubert, Daniel; Foulquié, Didier; Garnier, Eric

    2014-03-01

    Biomass production in grasslands, a key component of food provision for domestic herbivores, is known to depend on climate, resource availability, and on the functional characteristics of communities. However, the combined effects of these different factors remain largely unknown. The aim of the present study was to unravel the causes of variations in the standing biomass of plant communities using a long-term experiment conducted in a Mediterranean rangeland of Southern France. Two management regimes, sheep grazing and grazing associated with mineral fertilization, were applied to different areas of the study site over the past 25 years. Abiotic (temperature, available water, nutrients) and biotic (components of the functional structure communities) factors were considered to explain interannual and spatial variations in standing biomass in these rangelands. Standing biomass was highly predictable, with the best model explaining -80% of variations in the amount of biomass produced, but the variation explained by abiotic and biotic factors was dependent on the season and on the management regime. Abiotic factors were found to have comparable effects in both management regimes: The amount of biomass produced in the spring was limited by cold temperatures, while it was limited by water availability and high temperatures in the summer. In the fertilized community, the progressive change in the functional structure of the communities had significant effects on the amount of biomass produced: the dominance of few productive species which were functionally close led to higher peak standing biomass in spring.

  7. Inhibition of Fungal Plant Pathogens by Synergistic Action of Chito-Oligosaccharides and Commercially Available Fungicides

    PubMed Central

    Rahman, Md. Hafizur; Shovan, Latifur Rahman; Hjeljord, Linda Gordon; Aam, Berit Bjugan; Eijsink, Vincent G. H.; Sørlie, Morten; Tronsmo, Arne

    2014-01-01

    Chitosan is a linear heteropolymer consisting of β 1,4-linked N-acetyl-D-glucosamine (GlcNAc) and D-glucosamine (GlcN). We have compared the antifungal activity of chitosan with DPn (average degree of polymerization) 206 and FA (fraction of acetylation) 0.15 and of enzymatically produced chito-oligosaccharides (CHOS) of different DPn alone and in combination with commercially available synthetic fungicides, against Botrytis cinerea, the causative agent of gray mold in numerous fruit and vegetable crops. CHOS with DPn in the range of 15–40 had the greatest anti-fungal activity. The combination of CHOS and low dosages of synthetic fungicides showed synergistic effects on antifungal activity in both in vitro and in vivo assays. Our study shows that CHOS enhance the activity of commercially available fungicides. Thus, addition of CHOS, available as a nontoxic byproduct of the shellfish industry, may reduce the amounts of fungicides that are needed to control plant diseases. PMID:24770723

  8. Opportunities for improving phosphorus-use efficiency in crop plants.

    PubMed

    Veneklaas, Erik J; Lambers, Hans; Bragg, Jason; Finnegan, Patrick M; Lovelock, Catherine E; Plaxton, William C; Price, Charles A; Scheible, Wolf-Rüdiger; Shane, Michael W; White, Philip J; Raven, John A

    2012-07-01

    Limitation of grain crop productivity by phosphorus (P) is widespread and will probably increase in the future. Enhanced P efficiency can be achieved by improved uptake of phosphate from soil (P-acquisition efficiency) and by improved productivity per unit P taken up (P-use efficiency). This review focuses on improved P-use efficiency, which can be achieved by plants that have overall lower P concentrations, and by optimal distribution and redistribution of P in the plant allowing maximum growth and biomass allocation to harvestable plant parts. Significant decreases in plant P pools may be possible, for example, through reductions of superfluous ribosomal RNA and replacement of phospholipids by sulfolipids and galactolipids. Improvements in P distribution within the plant may be possible by increased remobilization from tissues that no longer need it (e.g. senescing leaves) and reduced partitioning of P to developing grains. Such changes would prolong and enhance the productive use of P in photosynthesis and have nutritional and environmental benefits. Research considering physiological, metabolic, molecular biological, genetic and phylogenetic aspects of P-use efficiency is urgently needed to allow significant progress to be made in our understanding of this complex trait.

  9. Advanced thermometrics for fossil power plant process improvement

    SciTech Connect

    Shepard, R.L.; Weiss, J.M.; Holcomb, D.E.

    1996-04-30

    Improved temperature measurements in fossil power plants can reduce heat rate and uncertainties in power production efficiencies, extend the life of plant components, reduce maintenance costs, and lessen emissions. Conventional instruments for measurement of combustion temperatures, steam temperatures, and structural component temperatures can be improved by better specification, in situ calibration, signal processing, and performance monitoring. Innovative instruments can enhance, augment, or replace conventional instruments. Several critical temperatures can be accessed using new methods that were impossible with conventional instruments. Such instruments include high temperature resistance temperature detectors (RTDs), thermometric phosphors, inductive thermometry, and ultrasonic thermometry.

  10. Using Publicly Available Data to Quantify Plant-Pollinator Interactions and Evaluate Conservation Seeding Mixes in the Northern Great Plains.

    PubMed

    Otto, C R V; O'Dell, S; Bryant, R B; Euliss, N H; Bush, R M; Smart, M D

    2017-06-01

    Concern over declining pollinators has led to multiple conservation initiatives for improving forage for bees in agroecosystems. Using data available through the Pollinator Library (npwrc.usgs.gov/pollinator/), we summarize plant-pollinator interaction data collected from 2012-2015 on lands managed by the U.S. Fish and Wildlife Service and private lands enrolled in U.S. Department of Agriculture conservation programs in eastern North Dakota (ND). Furthermore, we demonstrate how plant-pollinator interaction data from the Pollinator Library and seed cost information can be used to evaluate hypothetical seeding mixes for pollinator habitat enhancements. We summarize records of 314 wild bee and 849 honey bee (Apis mellifera L.) interactions detected on 63 different plant species. The wild bee observations consisted of 46 species, 15 genera, and 5 families. Over 54% of all wild bee observations were represented by three genera-Bombus, Lassioglossum, and Melissodes. The most commonly visited forbs by wild bees were Monarda fistulosa, Sonchus arvensis, and Zizia aurea. The most commonly visited forbs by A. mellifera were Cirsium arvense, Melilotus officinalis, and Medicago sativa. Among all interactions, 13% of A. mellifera and 77% of wild bee observations were made on plants native to ND. Our seed mix evaluation shows that mixes may often need to be tailored to meet the unique needs of wild bees and managed honey bees in agricultural landscapes. Our evaluation also demonstrates the importance of incorporating both biologic and economic information when attempting to design cost-effective seeding mixes for supporting pollinators in a critically important part of the United States. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  11. Oviposition Response by Orius Insidiosus (Hemiptera: Anthocoridae) to Plant Quality and Prey Availability

    USDA-ARS?s Scientific Manuscript database

    The predator Orius insidiosus consumes a mixed diet of prey, vascular sap, and plant-based foods through its life. Plant species identity affects the oviposition behavior of O. insidiosus in that it prefers plants where newly hatched nymphs perform best, in the absence of prey. Choice tests were ...

  12. 78 FR 45169 - GENECTIVE SA; Availability of Plant Pest Risk Assessment, Environmental Assessment, Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... and products altered or produced through genetic engineering that are plant pests or that there is... in 7 CFR part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,'' regulate, among other...

  13. 78 FR 13303 - Stine Seed Farm, Inc.; Availability of Plant Pest Risk Assessment, Environmental Assessment, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to... movement, or release into the environment) of organisms and products altered or produced through genetic engineering that are plant pests or that there is reason to believe are plant pests. Such genetically...

  14. 76 FR 37770 - Monsanto Co.; Availability of Petition, Plant Pest Risk Assessment, and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason To... movement, or release into the environment) of organisms and products altered or produced through genetic engineering that are plant pests or that there is reason to believe are plant pests. Such genetically...

  15. 78 FR 47272 - Monsanto Co.; Availability of Plant Pest Risk Assessment and Environmental Assessment for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... and products altered or produced through genetic engineering that are plant pests or that there is... regulations in 7 CFR part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,'' regulate, among other...

  16. 76 FR 27303 - Monsanto Co.; Availability of Petition, Plant Pest Risk Assessment, and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to... movement, or release into the environment) of organisms and products altered or produced through genetic engineering that are plant pests or that there is reason to believe are plant pests. Such genetically...

  17. Current status of the availability, development, and use of host plant resistance to nematodes.

    PubMed

    Roberts, P A

    1992-06-01

    Host plant resistance (HPR) to nematodes has been identified in many major crops and related wild germplasm. Most HPR is to the more specialized, sedentary endoparasitic genera and species, e.g., Globodera, Heterodera, Meloidogyne, Nacobbus, Rotylenchulus, and Tylenchulus. Some HPR has been developed or identified also to certain migratory endoparasites (Aphelenchoides, Ditylenchus, Pratylenchus, Radopholus) in a few hosts. Commercial use of HPR remains limited, despite its benefits to crop production when deployed appropriately. Restricted use and availability of HPR result from problems associated with transfer of resistance into acceptable cultivars. Difficulties occur in gene transfer to acceptable cultivars because of incompatibility barriers to hybridization or linkage to undesirable traits, for example in cucurbitaceous and solanaceous crops and sugarbeet. Specificity of HPR to only one species, or one or few pathotypes, as it relates to resistance durability and nematode virulence, and HPR response to abiotic factors such as high soil temperature, also limit availability and utility. A scheme for HPR development is presented to emphasize nematology research and information requirements for expanding HPR use in nematode control programs, for example in common bean, sugarbeet, and tomato. Nonbiological factors that influence HPR usage are discussed, including heavy reliance on nematicide programs, low priority of nematode HPR in many breeding programs, and insufficient breeder-nematologist collaboration.

  18. Physiologically available cyanide (PAC) in manufactured gas plant waste and soil samples

    SciTech Connect

    Magee, B.; Taft, A.; Ratliff, W.; Kelley, J.; Sullivan, J.; Pancorbo, O.

    1995-12-31

    Iron-complexed cyanide compounds, such as ferri-ferrocyanide (Prussian Blue), are wastes associated with former manufactured gas plant (MGP) facilities. When tested for total cyanide, these wastes often show a high total cyanide content. Because simple cyanide salts are acutely toxic, cyanide compounds can be the subject of concern. However, Prussian Blue and related species are known to have a low order of human and animal toxicity. Toxicology data on complexed cyanides will be presented. Another issue regarding Prussian Blue and related species is that the total cyanide method does not accurately represent the amount of free cyanide released from these cyanide species. The method involves boiling the sample in an acidic solution under vacuum to force the formation of HCN gas. Thus, Prussian Blue, which is known to be low in toxicity, cannot be properly evaluated with current methods. The Massachusetts Natural Gas Council initiated a program with the Massachusetts Department of Environmental Protection to develop a method that would define the amount of cyanide that is able to be converted into hydrogen cyanide under the pH conditions of the stomach. It is demonstrated that less than 1% of the cyanide present in Prussian Blue samples and soils from MGP sites can be converted to HCN under the conditions of the human stomach. The physiologically available cyanide method has been designed to be executed at a higher temperature for one hour. It is shown that physiologically available cyanide in MGP samples is < 5--15% of total cyanide.

  19. Climate and host plant availability impact the future distribution of the bean leaf beetle (Cerotoma trifurcata).

    PubMed

    Berzitis, Emily A; Minigan, Jordan N; Hallett, Rebecca H; Newman, Jonathan A

    2014-09-01

    The bean leaf beetle, Cerotoma trifurcata, has become a major pest of soybean throughout its North American range. With a changing climate, there is the potential for this pest to further expand its distribution and become an increasingly severe pest in certain regions. To examine this possibility, we developed bioclimatic envelope models for both the bean leaf beetle, and its most important agronomic host plant, soybean (Glycine max). These two models were combined to examine the potential future pest status of the beetle using climate change projections from multiple general circulation models (GCMs) and climate change scenarios. Despite the broad tolerances of soybean, incorporation of host plant availability substantially decreased the suitable and favourable areas for the bean leaf beetle as compared to an evaluation based solely on the climate envelope of the beetle, demonstrating the importance of incorporating biotic interactions in these predictions. The use of multiple GCM-scenario combinations also revealed differences in predictions depending on the choice of GCM, with scenario choice having less of an impact. While the Norwegian model predicted little northward expansion of the beetle from its current northern range limit of southern Ontario and overall decreases in suitable and favourable areas over time, the Canadian and Russian models predict that much of Ontario and Quebec will become suitable for the beetle in the future, as well as Manitoba under the Russian model. The Russian model also predicts expansion of the suitable and favourable areas for the beetle over time. Two predictions that do not depend on our choice of GCM include a decrease in suitability of the Mississippi Delta region and continued favourability of the southeastern United States.

  20. Improving the safety of LWR power plants. Final report

    SciTech Connect

    Not Available

    1980-04-01

    This report documents the results of the Study to identify current, potential research issues and efforts for improving the safety of Light Water Reactor (LWR) power plants. This final report describes the work accomplished, the results obtained, the problem areas, and the recommended solutions. Specifically, for each of the issues identified in this report for improving the safety of LWR power plants, a description is provided in detail of the safety significance, the current status (including information sources, status of technical knowledge, problem solution and current activities), and the suggestions for further research and development. Further, the issues are ranked for action into high, medium, and low priority with respect to primarily (a) improved safety (e.g. potential reduction in public risk and occupational exposure), and secondly (b) reduction in safety-related costs (improving or maintaining level of safety with simpler systems or in a more cost-effective manner).

  1. Conservation and restoration of indigenous plants to improve community livelihoods: the Useful Plants Project

    NASA Astrophysics Data System (ADS)

    Ulian, Tiziana; Sacandé, Moctar; Mattana, Efisio

    2014-05-01

    Kew's Millennium Seed Bank partnership (MSBP) is one of the largest ex situ plant conservation initiatives, which is focused on saving plants in and from regions most at risk, particularly in drylands. Seeds are collected and stored in seed banks in the country of origin and duplicated in the Millennium Seed Bank in the UK. The MSBP also strengthens the capacity of local communities to successfully conserve and sustainably use indigenous plants, which are important for their wellbeing. Since 2007, high quality seed collections and research information have been gathered on ca. 700 useful indigenous plant species that were selected by communities in Botswana, Kenya, Mali, Mexico and South Africa through Project MGU - The Useful Plants Project. These communities range from various farmer's groups and organisations to traditional healers, organic cotton/crop producers and primary schools. The information on seed conservation and plant propagation was used to train communities and to propagate ca. 200 species that were then planted in local gardens, and as species reintroduced for reforestation programmes and enriching village forests. Experimental plots have also been established to further investigate the field performance (plant survival and growth rate) of indigenous species, using low cost procedures. In addition, the activities support revenue generation for local communities directly through the sustainable use of plant products or indirectly through wider environmental and cultural services. This project has confirmed the potential of biodiversity conservation to improve food security and human health, enhance community livelihoods and strengthen the resilience of land and people to the changing climate. This approach of using indigenous species and having local communities play a central role from the selection of species to their planting and establishment, supported by complementary research, may represent a model for other regions of the world, where

  2. Genomics Approaches For Improving Salinity Stress Tolerance in Crop Plants

    PubMed Central

    Nongpiur, Ramsong Chantre; Singla-Pareek, Sneh Lata; Pareek, Ashwani

    2016-01-01

    Salinity is one of the major factors which reduces crop production worldwide. Plant responses to salinity are highly complex and involve a plethora of genes. Due to its multigenicity, it has been difficult to attain a complete understanding of how plants respond to salinity. Genomics has progressed tremendously over the past decade and has played a crucial role towards providing necessary knowledge for crop improvement. Through genomics, we have been able to identify and characterize the genes involved in salinity stress response, map out signaling pathways and ultimately utilize this information for improving the salinity tolerance of existing crops. The use of new tools, such as gene pyramiding, in genetic engineering and marker assisted breeding has tremendously enhanced our ability to generate stress tolerant crops. Genome editing technologies such as Zinc finger nucleases, TALENs and CRISPR/Cas9 also provide newer and faster avenues for plant biologists to generate precisely engineered crops. PMID:27499683

  3. Carbon availability triggers the decomposition of plant litter and assimilation of nitrogen by an ectomycorrhizal fungus

    PubMed Central

    Rineau, F; Shah, F; Smits, M M; Persson, P; Johansson, T; Carleer, R; Troein, C; Tunlid, A

    2013-01-01

    The majority of nitrogen in forest soils is found in organic matter–protein complexes. Ectomycorrhizal fungi (EMF) are thought to have a key role in decomposing and mobilizing nitrogen from such complexes. However, little is known about the mechanisms governing these processes, how they are regulated by the carbon in the host plant and the availability of more easily available forms of nitrogen sources. Here we used spectroscopic analyses and transcriptome profiling to examine how the presence or absence of glucose and/or ammonium regulates decomposition of litter material and nitrogen mobilization by the ectomycorrhizal fungus Paxillus involutus. We found that the assimilation of nitrogen and the decomposition of the litter material are triggered by the addition of glucose. Glucose addition also resulted in upregulation of the expression of genes encoding enzymes involved in oxidative degradation of polysaccharides and polyphenols, peptidases, nitrogen transporters and enzymes in pathways of the nitrogen and carbon metabolism. In contrast, the addition of ammonium to organic matter had relatively minor effects on the expression of transcripts and the decomposition of litter material, occurring only when glucose was present. On the basis of spectroscopic analyses, three major types of chemical modifications of the litter material were observed, each correlated with the expression of specific sets of genes encoding extracellular enzymes. Our data suggest that the expression of the decomposition and nitrogen assimilation processes of EMF can be tightly regulated by the host carbon supply and that the availability of inorganic nitrogen as such has limited effects on saprotrophic activities. PMID:23788332

  4. Summit on Improving the Economics of America's Nuclear Power Plants

    SciTech Connect

    Collins, John; Mason, Charles

    2016-09-01

    The Summit on Improving the Economics of America’s Nuclear Power Plants was convened May 19, 2016, by Secretary of Energy Ernest Moniz and co-sponsored by Idaho Senator Mike Crapo to stress the importance of existing nuclear reactors in meeting our nation’s energy goals. The summit was also designed to identify and discuss policy options that can be pursued at federal and state levels to address economic challenges, as well as technical options that utilities can use to improve the economic competitiveness of operating nuclear power plants (NPPs) and avoid early plant retirements that are driven by temporary market conditions. The owners of NPPs face difficult economic decisions and are working to improve the performance of existing NPPs. However, it soon became clear that some of the actions taken by states and regional markets have had an impact on the economic viability of existing power plants, including carbon free NPPs. Summit speakers identified concepts and actions that could be taken at state and federal levels to improve the economics of the existing fleet within these regulated and restructured electricity markets. This report summarizes the speeches, concepts, and actions taken.

  5. Planting Grass Appears Impratical For Improving Deteriorated Recreation Sites

    Treesearch

    H. Ken Cordell; Daniel R. Talhelm

    1969-01-01

    There is a real need for improving the physical condition of many recreation sires in the Southeast which are characterized by compacted and eroding soils, dead and dying vegetation, and generally poor appearance. An attempt was made on these sites to establish grass by giving the best possible treatment for growth and survival. After one summer of use, the planted...

  6. Improving planting stock quality—the Humboldt experience

    Treesearch

    James L. Jenkinson; James A. Nelson

    1993-01-01

    A seedling testing program was developed to improve the survival and growth potential of planting stock produced in the USDA Forest Service Humboldt Nursery, situated on the Pacific Coast in northern California. Coastal and inland seed sources of Douglas-fir and eight other conifers in the Pacific Slope forests of western Oregon and northern California were assessed in...

  7. Availability, production, and consumption of crops biofortified by plant breeding: current evidence and future potential.

    PubMed

    Saltzman, Amy; Birol, Ekin; Oparinde, Adewale; Andersson, Meike S; Asare-Marfo, Dorene; Diressie, Michael T; Gonzalez, Carolina; Lividini, Keith; Moursi, Mourad; Zeller, Manfred

    2017-02-01

    Biofortification is the process of increasing the density of vitamins and minerals in a crop through plant breeding-using either conventional methods or genetic engineering-or through agronomic practices. Over the past 15 years, conventional breeding efforts have resulted in the development of varieties of several staple food crops with significant levels of the three micronutrients most limiting in diets: zinc, iron, and vitamin A. More than 15 million people in developing countries now grow and consume biofortified crops. Evidence from nutrition research shows that biofortified varieties provide considerable amounts of bioavailable micronutrients, and consumption of these varieties can improve micronutrient deficiency status among target populations. Farmer adoption and consumer acceptance research shows that farmers and consumers like the various production and consumption characteristics of biofortified varieties, as much as (if not more than) popular conventional varieties, even in the absence of nutritional information. Further development and delivery of these micronutrient-rich varieties can potentially reduce hidden hunger, especially in rural populations whose diets rely on staple food crops. Future work includes strengthening the supply of and the demand for biofortified staple food crops and facilitating targeted investment to those crop-country combinations that have the highest potential nutritional impact.

  8. Biomass Allocation of Stoloniferous and Rhizomatous Plant in Response to Resource Availability: A Phylogenetic Meta-Analysis

    PubMed Central

    Xie, Xiu-Fang; Hu, Yu-Kun; Pan, Xu; Liu, Feng-Hong; Song, Yao-Bin; Dong, Ming

    2016-01-01

    Resource allocation to different functions is central in life-history theory. Plasticity of functional traits allows clonal plants to regulate their resource allocation to meet changing environments. In this study, biomass allocation traits of clonal plants were categorized into absolute biomass for vegetative growth vs. for reproduction, and their relative ratios based on a data set including 115 species and derived from 139 published literatures. We examined general pattern of biomass allocation of clonal plants in response to availabilities of resource (e.g., light, nutrients, and water) using phylogenetic meta-analysis. We also tested whether the pattern differed among clonal organ types (stolon vs. rhizome). Overall, we found that stoloniferous plants were more sensitive to light intensity than rhizomatous plants, preferentially allocating biomass to vegetative growth, aboveground part and clonal reproduction under shaded conditions. Under nutrient- and water-poor condition, rhizomatous plants were constrained more by ontogeny than by resource availability, preferentially allocating biomass to belowground part. Biomass allocation between belowground and aboveground part of clonal plants generally supported the optimal allocation theory. No general pattern of trade-off was found between growth and reproduction, and neither between sexual and clonal reproduction. Using phylogenetic meta-analysis can avoid possible confounding effects of phylogeny on the results. Our results shown the optimal allocation theory explained a general trend, which the clonal plants are able to plastically regulate their biomass allocation, to cope with changing resource availability, at least in stoloniferous and rhizomatous plants. PMID:27200071

  9. Biomass Allocation of Stoloniferous and Rhizomatous Plant in Response to Resource Availability: A Phylogenetic Meta-Analysis.

    PubMed

    Xie, Xiu-Fang; Hu, Yu-Kun; Pan, Xu; Liu, Feng-Hong; Song, Yao-Bin; Dong, Ming

    2016-01-01

    Resource allocation to different functions is central in life-history theory. Plasticity of functional traits allows clonal plants to regulate their resource allocation to meet changing environments. In this study, biomass allocation traits of clonal plants were categorized into absolute biomass for vegetative growth vs. for reproduction, and their relative ratios based on a data set including 115 species and derived from 139 published literatures. We examined general pattern of biomass allocation of clonal plants in response to availabilities of resource (e.g., light, nutrients, and water) using phylogenetic meta-analysis. We also tested whether the pattern differed among clonal organ types (stolon vs. rhizome). Overall, we found that stoloniferous plants were more sensitive to light intensity than rhizomatous plants, preferentially allocating biomass to vegetative growth, aboveground part and clonal reproduction under shaded conditions. Under nutrient- and water-poor condition, rhizomatous plants were constrained more by ontogeny than by resource availability, preferentially allocating biomass to belowground part. Biomass allocation between belowground and aboveground part of clonal plants generally supported the optimal allocation theory. No general pattern of trade-off was found between growth and reproduction, and neither between sexual and clonal reproduction. Using phylogenetic meta-analysis can avoid possible confounding effects of phylogeny on the results. Our results shown the optimal allocation theory explained a general trend, which the clonal plants are able to plastically regulate their biomass allocation, to cope with changing resource availability, at least in stoloniferous and rhizomatous plants.

  10. Micronutrient fortification of plants through plant breeding: can it improve nutrition in man at low cost?

    PubMed

    Bouis, Howarth E

    2003-05-01

    Can commonly-eaten food staple crops be developed that fortify their seeds with essential minerals and vitamins? Can farmers be induced to grow such varieties? If so, would this result in a marked improvement in human nutrition at a lower cost than existing nutrition interventions? An interdisciplinary international effort is underway to breed for mineral- and vitamin-dense varieties of rice, wheat, maize, beans and cassava for release to farmers in developing countries. The biofortification strategy seeks to take advantage of the consistent daily consumption of large amounts of food staples by all family members, including women and children as they are most at risk for micronutrient malnutrition. As a consequence of the predominance of food staples in the diets of the poor, this strategy implicitly targets low-income households. After the one-time investment is made to develop seeds that fortify themselves, recurrent costs are low and germplasm may be shared internationally. It is this multiplier aspect of plant breeding across time and distance that makes it so cost-effective. Once in place, the biofortified crop system is highly sustainable. Nutritionally-improved varieties will continue to be grown and consumed year after year, even if government attention and international funding for micronutrient issues fades. Biofortification provides a truly feasible means of reaching malnourished populations in relatively remote rural areas, delivering naturally-fortified foods to population groups with limited access to commercially-marketed fortified foods that are more readily available in urban areas. Biofortification and commercial fortification are, therefore, highly complementary. Breeding for higher trace mineral density in seeds will not incur a yield penalty. Mineral-packed seeds sell themselves to farmers because, as recent research has shown, these trace minerals are essential in helping plants resist disease and other environmental stresses. More seedlings

  11. Compost biofortification with diazotrophic and P-solubilizing bacteria improves maturation process and P availability.

    PubMed

    Busato, Jader G; Zandonadi, Daniel B; Mól, Alan R; Souza, Rafaela S; Aguiar, Kamilla P; Júnior, Fábio B Reis; Olivares, Fábio L

    2017-02-01

    Phosphorus-containing fertilizers play an important role in tropical agriculture owing to the well documented shortage of plant-available P in soils. Traditional P fertilizer production is based on chemical processing of insoluble rock phosphate (RP), which includes an acid treatment at high temperature. Processing the RP increases fertilizer costs, making it unavailable for undercapitalized and typically family-based farmers. Biotechnological methods have been proposed as an alternative to increase phosphate availability in RP. In this study, Burkholderia silvatlantica and Herbaspirillum seropedicae were co-inoculated into an RP-enriched compost with the aim of determining the effects of this technology on the levels of phosphatase activities and release of plant-available P. Inoculation of both microorganisms resulted in higher organic matter decomposition and higher humic acid formation in composting. Herbaspirillum seropedicae was the most promising microorganism for the production of acid and alkaline phosphatase enzymes. Both microorganisms presented potential to increase the supply of P from poorly soluble sources owing to increased levels of water-soluble P and citric acid P. Burkholderia silvatlantica and H. seropedicae in RP-enriched compost may represent an important biotechnological tool to reduce the overall time required for composting and increase the supply of P from poorly soluble sources. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Root Traits and Phenotyping Strategies for Plant Improvement.

    PubMed

    Paez-Garcia, Ana; Motes, Christy M; Scheible, Wolf-Rüdiger; Chen, Rujin; Blancaflor, Elison B; Monteros, Maria J

    2015-06-15

    Roots are crucial for nutrient and water acquisition and can be targeted to enhance plant productivity under a broad range of growing conditions. A current challenge for plant breeding is the limited ability to phenotype and select for desirable root characteristics due to their underground location. Plant breeding efforts aimed at modifying root traits can result in novel, more stress-tolerant crops and increased yield by enhancing the capacity of the plant for soil exploration and, thus, water and nutrient acquisition. Available approaches for root phenotyping in laboratory, greenhouse and field encompass simple agar plates to labor-intensive root digging (i.e., shovelomics) and soil boring methods, the construction of underground root observation stations and sophisticated computer-assisted root imaging. Here, we summarize root architectural traits relevant to crop productivity, survey root phenotyping strategies and describe their advantages, limitations and practical value for crop and forage breeding programs.

  13. Root Traits and Phenotyping Strategies for Plant Improvement

    PubMed Central

    Paez-Garcia, Ana; Motes, Christy M.; Scheible, Wolf-Rüdiger; Chen, Rujin; Blancaflor, Elison B.; Monteros, Maria J.

    2015-01-01

    Roots are crucial for nutrient and water acquisition and can be targeted to enhance plant productivity under a broad range of growing conditions. A current challenge for plant breeding is the limited ability to phenotype and select for desirable root characteristics due to their underground location. Plant breeding efforts aimed at modifying root traits can result in novel, more stress-tolerant crops and increased yield by enhancing the capacity of the plant for soil exploration and, thus, water and nutrient acquisition. Available approaches for root phenotyping in laboratory, greenhouse and field encompass simple agar plates to labor-intensive root digging (i.e., shovelomics) and soil boring methods, the construction of underground root observation stations and sophisticated computer-assisted root imaging. Here, we summarize root architectural traits relevant to crop productivity, survey root phenotyping strategies and describe their advantages, limitations and practical value for crop and forage breeding programs. PMID:27135332

  14. Ways to Improve Russian Coal-Fired Power Plants

    SciTech Connect

    Tumanovskii, A. G. Olkhovsky, G. G.

    2015-07-15

    Coal is an important fuel for the electric power industry of Russia, especially in Ural and the eastern part of the country. It is fired in boilers of large (200 – 800 MW) condensing power units and in many cogeneration power plants with units rated at 50 – 180 MW. Many coal-fired power plants have been operated for more than 40 – 50 years. Though serviceable, their equipment is obsolete and does not comply with the current efficiency, environmental, staffing, and availability standards. It is urgent to retrofit and upgrade such power plants using advanced equipment, engineering and business ideas. Russian power-plant engineering companies have designed such advanced power units and their equipment such as boilers, turbines, auxiliaries, process and environmental control systems similar to those produced by the world’s leading manufacturers. Their performance and ways of implementation are discussed.

  15. Biochar Improves Soil Aggregate Stability and Water Availability in a Mollisol after Three Years of Field Application

    PubMed Central

    Zhang, Yulan; Yang, Lijie; Yu, Chunxiao; Yin, Guanghua; Doane, Timothy A.; Wu, Zhijie; Zhu, Ping; Ma, Xingzhu

    2016-01-01

    A field experiment was carried out to evaluate the effect of organic amendments on soil organic carbon, total nitrogen, bulk density, aggregate stability, field capacity and plant available water in a representative Chinese Mollisol. Four treatments were as follows: no fertilization (CK), application of inorganic fertilizer (NPK), combined application of inorganic fertilizer with maize straw (NPK+S) and addition of biochar with inorganic fertilizer (NPK+B). Our results showed that after three consecutive years of application, the values of soil bulk density were significantly lower in both organic amendment-treated plots than in unamended (CK and NPK) plots. Compared with NPK, NPK+B more effectively increased the contents of soil organic carbon, improved the relative proportion of soil macro-aggregates and mean weight diameter, and enhanced field capacity as well as plant available water. Organic amendments had no obvious effect on soil C/N ratio or wilting coefficient. The results of linear regression indicated that the improvement in soil water retention could be attributed to the increases in soil organic carbon and aggregate stability. PMID:27191160

  16. Trace element availability and plant growth in a mine-spill-contaminated soil under assisted natural remediation II. Plants.

    PubMed

    Pérez-de-Mora, Alfredo; Madejón, Engracia; Burgos, Pilar; Cabrera, Francisco

    2006-06-15

    In this second part, we evaluated the effects of different amendments on plant growth (Agrostis stolonifera L.), and trace element accumulation and removal by plants in a trace element (As, Cd, Cu, Pb and Zn) contaminated soil. Description of the various treatments is given in Part I of this work. The plants were grown for consecutive periods (2002, 2003, 2004), 5 months each and harvested twice in each period. Results showed that plant growth was enhanced and trace element concentrations in plant were reduced in SL, MWC, BC and LEO treatments in the first period. No significant differences were observed in subsequent periods. This seemed to be related with changes in soil pH. Removal of trace elements was higher in SL, MWC, BC and LEO treatments due to higher biomass production in the first period. In following years no significant differences between treatments were found. Data from Part I of this study were also used to compare trace element bioavailable concentrations extracted with 0.01 M CaCl2 and 0.05 M EDTA with trace elements in plant. We observed that 0.01 M CaCl2 was more suitable for determination of bioavailable concentrations and that extraction with EDTA overestimated biovailability of trace elements in amended treatments, especially in those where composts were added.

  17. How increased extreme precipitation under future climate change affects plant water stress and water availability.

    NASA Astrophysics Data System (ADS)

    Eekhout, Joris P. C.; Hunink, Johannes E.; de Vente, Joris

    2017-04-01

    For many areas worldwide, increased rainfall intensity and frequency of extreme weather events are projected for the coming century. This will have effect on water security and soil erosion in large parts of the world. Here we present a detailed catchment-scale study, arguing that global and regional studies may be insufficiently accurate to describe actual impacts on the redistribution of water and the consequences for soil erosion. We applied a hydrological model, including infiltration excess surface runoff, coupled with an erosion model. The model was applied to 1 reference and 4 future climate scenarios (2 periods and 2 Representative Concentration Pathways), consisting of an ensemble of 9 Regional Climate Models. The climatic input for the future scenarios was bias-corrected using quantile mapping. Our results show a significant increase of plant water stress, reservoir inflow, soil erosion and reservoir sedimentation in all 4 future scenarios. Hence, a redistribution of water is expected, where agriculture may shift from rainfed to irrigated crops as a result of decreasing soil moisture and increased reservoir inflow. At the same time, reservoir sedimentation increases and threatens long-term sustainability of water storage and water security. Our results emphasize the role infiltration excess surface runoff and bias-correction methods play in the quantification of the impact of increased intense precipitation on water availability and soil erosion at the catchment scale.

  18. Phytochemicals in plants: genomics-assisted plant improvement for nutritional and health benefits.

    PubMed

    Grusak, Michael A

    2002-10-01

    Plants are an important source of essential nutrients and health-beneficial components that are crucial for human life. Because the intake of these phytochemicals is not always adequate, the resources of plant biotechnology are being used to enhance the nutritional quality of our plant-based food supply. Various improvement strategies are feasible, depending on whether the phytochemical target is a major or minor constituent. Recent efforts in gene discovery and functional genomics are providing the necessary understanding to develop and evaluate different approaches to manipulate phytochemical composition.

  19. Flood flows, leaf breakdown, and plant-available nitrogen on a dryland river floodplain

    USGS Publications Warehouse

    Andersen, Douglas C.; Nelson, S. Mark; Binkley, Dan

    2003-01-01

    We tested the hypothesis that decomposition in flood-inundated patches of riparian tree leaf litter results in higher plant-available nitrogen in underlying, nutrient-poor alluvium. We used leafpacks (n = 56) containing cottonwood (Populus deltoides ssp. wislizenii) leaf litter to mimic natural accumulations of leaves in an experiment conducted on the Yampa River floodplain in semi-arid northwestern Colorado, USA. One-half of the leafpacks were set on the sandy alluvial surface, and one-half were buried 5 cm below the surface. The presence of NO3− and NH4+ presumed to result from a leafpack's submergence during the predictable spring flood pulse was assessed using an ion-exchange resin bag (IER) placed beneath each leafpack and at control locations. Leafpacks and IERs were collected one week after flood peak (71 days total exposure) at half the stations; the remainder were collected three weeks later (93 days exposure). A multi-peaked spring flood with above-average maximum discharge inundated leafpacks for total time periods ranging from 133 to 577 hours. Litter lost from 43 to 68 percent of its initial organic matter (OM) content. Organic matter loss increased with total time inundated and total time of exposure on the floodplain. Burial retarded OM loss if the total time inundated was relatively long, and substrate texture (sand vs. silt) affected OM loss in a complex manner through interactions with total time inundated and total time of exposure. No pulse of N attributable to leaf breakdown was detected in the IERs, and leafpack litter showed no net change in the mass of nitrogen present. Patterns of leafpack and IER nitrogen levels suggested that litter removed N from floodwater and thereby reduced N availability in underlying sediment. Immobilization of floodwater-N by litter and N mineralization outside the flood period may be important components of N flux in semi-arid and arid floodplain environments.

  20. Nitrogen availability drives the effect of Glomus intraradices on the growth of strawberry (Fragaria x ananassa Duch.) plants.

    PubMed

    Castellanos-Morales, Vilma; Villegas-Moreno, Javier; Vierheilig, Horst; Cárdenas-Navarro, Raúl

    2012-08-30

    On the one hand, the critical nitrogen (N) content curve allows the minimal N content necessary for maximum growth rate at any stage of crop development to be predicted. On the other hand, arbuscular mycorrhizal fungi (AMF) transfer N from the soil to the plants and its growth and activity depends on the availability of soil N. Our objective was to investigate how the availability of N in the soil affects growth and the accumulation of N in inoculated strawberry plants. Root colonisation, dry matter accumulation and the critical N% curve were studied during growth of inoculated and non-inoculated strawberry plants grown at several N levels. (1) The increase in the availability of N augmented root colonisation by AMF. (2) The effect of AMF on plant growth depended on N availability and the plant developmental status. (3) The critical %N curves were fitted by the following equations: %N = 2.81× (DM)(-0.21) (r² = 0.81) and %N = 2.89× (DM)(-0.32) (r² = 0.80) for inoculated and non-inoculated plants, respectively (where DM is the weight of leaf dry matter, in g plant⁻¹). N availability was a key factor for root colonisation by AMF and for its contribution to plant growth. The patterns of the critical %N curves suggest that AMF modified the photosynthetic N use efficiency. Copyright © 2012 Society of Chemical Industry.

  1. Improving geothermal power plants with a binary cycle

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  2. Improving the environmental sustainability of a waste processing plant

    SciTech Connect

    Turner, Tom; Watson, Stuart

    2013-07-01

    This paper describes how the level of environmental sustainability at the Solid Waste Processing plant at Research Sites Restoration Ltd (RSRL) Harwell was measured and improved. It provides reasons to improve environmental performance in an organisation, states best practice on how improvement should be conducted, and gives first-hand experience on how changes were implemented. In this paper sustainability is defined as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs'. A baseline for environmental sustainability was created, by looking at multiple attributes. From this, a matrix was created to show how the baseline environmental performance compared to best practice, and a gap analysis was performed. Results from this analysis showed areas for potential systematic improvement, and actions were created. Nearly all actions were implemented within one year, and environmental sustainability improved significantly. Most improvements cost no money to implement, and the few that did had to pass criteria in a business case. Results from a company-wide survey showed that the vast majority of employees felt that environmental issues were important, and that they were willing to help improve performance. Environmental awareness training was given to everyone in the department, and individuals were given measurable improvement targets. A focus group was set up and met regularly to agree improvements and monitor results. Environmental performance was publicised regularly to highlight successes and seek further engagement and improvement. Improvement ideas were encouraged and managed in a transparent way which showed clear prioritisation and accountability. The culture of environmental improvement changed visibly and results at the end of the first year showed that electricity consumption had reduced by 12.5%, and gas consumption had reduced by 7.3%. In less than two years over UK Pound 60,000 was saved on utility

  3. Availability Of Deep Groundwater-Derived CO2 For Plant Uptake In A Costa Rican Rainforest

    NASA Astrophysics Data System (ADS)

    Oberbauer, S. F.; Genereux, D. P.; Osburn, C. L.; Dierick, D.; Oviedo Vargas, D.

    2014-12-01

    isotopically-heavy CO2 from the Arboleda stream. Keeling plots of samples taken at the Arboleda and Sura deviated from those over the Taconazo and indicated a source of 13C other than atmospheric air and respired CO2. Our data suggest that CO2 from regional groundwater has the potential to be available to riparian plants, but primarily at areas of turbulent water flow.

  4. Aquatic Plant Control Research Program. Interactions between Macrophyte Growth and Sediment Nutrient Availability.

    DTIC Science & Technology

    1988-04-01

    freshwater systems. I25 Ul 0 , S 0 REFERENCES Agami, M. and Waisel, Y., 1986. The ecophysiology of roots of submerged vascular plants . Physiol. Veg., 24:607...349-354. Sculthorpe, C. D., 1967. The Biology of Aquatic Vascular Plants . Edward Arnold, London, 610 pp. Short, F. T., 1983. The response of

  5. Estimating plant available water for general crop simulations in ALMANAC/APEX/EPIC/SWAT

    USDA-ARS?s Scientific Manuscript database

    Process-based simulation models ALMANAC/APEX/EPIC/SWAT contain generalized plant growth subroutines to predict biomass and crop yield. Environmental constraints typically restrict plant growth and yield. Water stress is often an important limiting factor; it is calculated as the sum of water use f...

  6. Wood-based panel plant locations and timber availability in selected U.S. states

    Treesearch

    T. McKeever; H. N. Spelter

    1998-01-01

    This report lists wood-based panel industry plant locations, production capacities, timber inventories, and wood costs for 24 U.S. states. Industry sectors covered include medium-density fiberboard, particleboard, softwood plywood, and oriented strandboard. Maps of major forest producing states show plant locations and the underlying density of timber stocking by...

  7. 78 FR 4297 - Improving Availability of Relevant Executive Branch Records to the National Instant Criminal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... Documents#0;#0; ] Memorandum of January 16, 2013 Improving Availability of Relevant Executive Branch Records to the National Instant Criminal Background Check System Memorandum for the Heads of Executive... its requirements, the NIAA mandated that executive departments and agencies (agencies)...

  8. School Improvement and the Availability of Substitute Teachers in Ohio: An Irony of Professional Development.

    ERIC Educational Resources Information Center

    Griswold, Phillip A.; Hughes, William

    2000-01-01

    Investigated the availability of qualified substitute teachers in Ohio and the impact of a shortage on school improvement efforts. Surveys of district superintendents indicated a shortage of qualified substitute teachers related to district policy and procedures and increasing professional development demands for regular teachers. This shortage…

  9. Rearing conditions influence nutrient availability of plant extracts supplemented diets when fed to broiler chickens.

    PubMed

    Pirgozliev, V; Bravo, D; Rose, S P

    2014-08-01

    The effects of a standardised mixture of essential oils, including 5% carvacrol, 3% cinnamaldehyde and 2% capsicum (XT 6930; Pancosma S.A), on dietary apparent metabolisable energy corrected for nitrogen retention (AMEn), nutrient digestibility and mucin secretions, measured as sialic acid (SA) were investigated in broilers fed on the same diet but reared under different conditions, that is, cages and floor pens littered with wood shavings used in previous broiler study. The use of XT reduced (p < 0.05) nitrogen digestibility (0.585 vs. 0.544) and tended (p = 0.072) to reduce dry matter digestibility (0.733 vs. 0.717) of the diet when fed to birds reared in cages. However, XT supplementation improved (p < 0.05) fat digestibility (0.844 vs. 0.862) and tended (p = 0.093) to increase AMEn (14.01 vs. 14.25 MJ/kg DM) of the same diet when fed to broilers reared in floor pens. Essential oils supplementation tended (p = 0.059) to increase the secretion of SA, when fed to birds reared in cages (11.24 vs. 14.18 μg), but did not influence (p > 0.05) the SA secretion from birds reared in floor pens. The results obtained from the cage study tend to be the opposite of those obtained from the floor pen study. This suggests that the efficiency of dietary plant extracts may be influenced by the rearing/hygienic conditions of poultry. Based on the overall results, it can be concluded that information on rearing conditions should be taken into account for more complete interpretation of the experimental data emanating from experiments involving use of essential oils typified by those considered in this study. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

  10. EARLY ENTRANCE CO-PRODUCTION PLANT - DECENTRALIZED GASIFICATION COGENERATION TRANSPORTATION FUELS AND STEAM FROM AVAILABLE FEEDSTOCKS

    SciTech Connect

    Unknown

    2001-07-01

    Waste Processors Management Inc. (WMPI), along with its subcontractors entered into a cooperative agreement with the USDOE to assess the techno-economic viability of building an Early Entrance Co-Production Plant (EECP) in the US that produces ultra clean Fischer-Tropsch transportation fuels with either power or steam as the major co-product. The EECP will emphasize on reclaiming and gasifying low-cost coal waste and/or its mixture as the primary feedstocks. The project consists of three phases. Phase I objectives include conceptual development, technical assessment, feasibility design and economic evaluation of a Greenfield commercial co-production plant and a site specific demonstration EECP to be located adjacent to the existing WMPI Gilberton Power Station. There is very little foreseen design differences between the Greenfield commercial coproduction plant versus the EECP plant other than: The greenfield commercial plant will be a stand alone FT/power co-production plant, potentially larger in capacity to take full advantage of economy of scale, and to be located in either western Pennsylvania, West Virginia or Ohio, using bituminous coal waste (gob) and Pennsylvania No.8 coal or other comparable coal as the feedstock; The EECP plant, on the other hand, will be a nominal 5000 bpd plant, fully integrated into the Gilbertson Power Company's Cogeneration Plant to take advantage of the existing infrastructure to reduce cost and minimize project risk. The Gilberton EECP plant will be designed to use eastern Pennsylvania anthracite coal waste and/or its mixture as feedstock.

  11. Predicting plant hydraulic risk in a seasonally dry climate from plant traits and probabilistic soil water availability

    NASA Astrophysics Data System (ADS)

    Feng, X.; Thompson, S. E.; Ackerly, D.; Dawson, T. E.; Santiago, L. S.

    2016-12-01

    Projected increases in precipitation variability will likely induce more instances of plant mortality, due to hydraulic failure under extreme water deficit. Plants respond to the full range of hydroclimatic variability and its associated extremes, but current models addressing vegetation response to climate change rarely account for these temporal dynamics in a mechanistic way. Here, we couple a simple plant hydraulics model with a soil moisture model and, for the first time, translate external rainfall forcings—with variability explicitly described at daily, seasonal, and interannual timescales—into physiologically meaningful risk metrics of hydraulic failure. The model, parameterized with measured traits from a set of chaparral species native to southern California, shows that apparently similar functional outcomes, such as high or low transpiration levels throughout the dry season, can emerge from disparate hydraulic pathways. We demonstrate how the multiple traits involved in regulating plant water use across the soil-plant-atmosphere continuum can be captured through a parsimonious set of parameters, and then use these parameters to derive the probabilistic risk of hydraulic failure for each species as a function of rainfall statistics. The resulting differences in species' vulnerability to seasonal and interannual rainfall statistics suggests that shifts in these hydroclimatic variables could alter species composition in this region due to species-specific changes in hydraulic risk. Our process-based approach offers a quantitative framework for understanding species sensitivity across multiple timescales of rainfall variability and provides a promising avenue towards incorporating interactions of temporal variability and physiological mechanisms into drought response models.

  12. Effectiveness of pharmacy interventions in improving availability of essential medicines at the primary healthcare level.

    PubMed

    Nunan, Michael; Duke, Trevor

    2011-05-01

    To assess the effectiveness of pharmaceutical systems interventions in improving the availability of essential medicines at the primary care level. Literature search for examples of pharmaceutical systems interventions in low and middle income countries that evaluated the impact of specific interventions on medicines' availability. Qualitative and quantitative studies were included. Seventeen studies were included, on privatisation of drug distribution, user-fees, revolving drug funds (RDFs), supervisory visitation programmes, staff training initiatives, community-directed interventions (CDIs) and disease-specific drug programmes. We found no studies on non-monetary staff incentives or the use of national pharmacy standards. Generally, the quantity and quality of evidence was low; evidence was strongest for supervisory visitation programmes and CDIs. Several interventions have the potential for improving medicines' availability without requiring large-scale international cooperation or global policy change. The absence of evidence in this field does not prove lack of effect. There is a need for more systematic studies of multi-faceted pharmaceutical interventions to improve drug availability in the context of difficult health systems, such as structured supervision of remote health facilities, CDIs, staff training, integration of disease-specific programmes, implementation of national pharmacy standards, non-monetary staff incentives and measures to ensure cost is not a barrier to access. A standardised approach to measuring the availability of essential medicines is needed. © 2011 Blackwell Publishing Ltd.

  13. A Hybrid Quorum Protocol for Improved Availability, Capacity, Load and Reduced Overhead

    NASA Astrophysics Data System (ADS)

    Pandey, Parul; Tripathi, Maheshwari

    2016-12-01

    Data replication is playing a vital role in the design of distributed information systems. This paper presents a novel and efficient distributed algorithm for managing replicated data and for better performance and availability. This paper presents an extension to existing wheel protocol for improved performance. Wheel protocol imposes a logical wheel structure on the set of copies of an object and gives smallest read quorum. In addition to small read quorum size for read intensive applications, it is necessary to have good write availability as well. This paper proposes two hybrid wheel protocols, which superimpose logarithmic and ring protocols on top of the wheel protocol. It shows that, both protocols help in improving write availability, read capacity, load and message overhead and also compare their performances with wheel and other protocols. Hybrid protocols expand usage of wheel protocol to different type of applications.

  14. Control of Seed Germination and Plant Development by Carbon and Nitrogen Availability.

    PubMed

    Osuna, Daniel; Prieto, Pilar; Aguilar, Miguel

    2015-01-01

    Little is known about the molecular basis of the influence of external carbon/nitrogen (C/N) ratio and other abiotic factors on phytohormones regulation during seed germination and plant developmental processes, and the identification of elements that participate in this response is essential to understand plant nutrient perception and signaling. Sugars (sucrose, glucose) and nitrate not only act as nutrients but also as signaling molecules in plant development. A connection between changes in auxin transport and nitrate signal transduction has been reported in Arabidopsis thaliana through the NRT1.1, a nitrate sensor and transporter that also functions as a repressor of lateral root growth under low concentrations of nitrate by promoting auxin transport. Nitrate inhibits the elongation of lateral roots, but this effect is significantly reduced in abscisic acid (ABA)-insensitive mutants, what suggests that ABA might mediate the inhibition of lateral root elongation by nitrate. Gibberellin (GA) biosynthesis has been also related to nitrate level in seed germination and its requirement is determined by embryonic ABA. These mechanisms connect nutrients and hormones signaling during seed germination and plant development. Thus, the genetic identification of the molecular components involved in nutrients-dependent pathways would help to elucidate the potential crosstalk between nutrients, nitric oxide (NO) and phytohormones (ABA, auxins and GAs) in seed germination and plant development. In this review we focus on changes in C and N levels and how they control seed germination and plant developmental processes through the interaction with other plant growth regulators, such as phytohormones.

  15. Peppermint trees shift their phosphorus-acquisition strategy along a strong gradient of plant-available phosphorus by increasing their transpiration at very low phosphorus availability.

    PubMed

    Huang, Gang; Hayes, Patrick E; Ryan, Megan H; Pang, Jiayin; Lambers, Hans

    2017-09-18

    Some plant species use different strategies to acquire phosphorus (P) dependent on environmental conditions, but studies investigating the relative significance of P-acquisition strategies with changing P availability are rare. We combined a natural P availability gradient and a glasshouse study with 10 levels of P supplies to investigate the roles of rhizosphere carboxylates and transpiration-driven mass flow in P acquisition by Agonis flexuosa. Leaf P concentrations of A. flexuosa decreased and leaf manganese (Mn) concentrations increased with decreasing soil P concentration along a dune chronosequence. In the glasshouse, in response to decreasing P supply, shoot growth and root length decreased, leaf P and Mn concentrations decreased, rhizosphere carboxylates decreased, transpiration rate and transpiration ratio increased and the percentage of root length colonized by arbuscular mycorrhizal fungi was unchanged. Although it was proved leaf Mn concentration was a good proxy for rhizosphere carboxylate amounts in the glasshouse study, the enhanced plant P acquisition at low P supply was related to transpiration-induced mass flow rather than carboxylates. We deduced that the higher leaf Mn concentrations in low soil P availability of the field were likely a result of increased mass flow. In summary, as soil P availability declined, A. flexuosa can shift its P-acquisition strategy away from a mycorrhizal mode towards one involving increased mass flow.

  16. Improved Construction and Project Management for Future Nuclear Power Plants - Westinghouse Perspective

    SciTech Connect

    Matzie, Regis A.

    2002-07-01

    The economic competitiveness of future nuclear power plants is the key issue to the expansion of this vital technology. The challenge is greater today than it has been because of the worldwide trend of deregulation of the power market. Deregulation favors smaller investments with shorter payback times. However, the key economic parameter is the power generation cost and its competitiveness to other sources of electric generation, principally natural gas and coal. The relative competitiveness of these three fuel types today is largely dictated by the availability of domestic sources of both fuel and technology infrastructure. The competitiveness of new nuclear power plants can be improved in any power market environment first by the features of the design itself, second by the approach to construction, and finally by the project structure used to implement the plant, or more importantly, a series of plants. These three aspects form the cornerstone to a successful resurgence of new nuclear power plant construction. (author)

  17. Soil nitrogen availability, plant luxury consumption, and herbivory by white-tailed deer.

    PubMed

    Tripler, C; Canham, C; Inouye, R; Schnurr, J

    2002-12-01

    N is often cited as a limiting factor for sapling growth in northeastern USA forests. However, under conditions of elevated soil N, seedlings and saplings of some tree species exhibit luxury consumption of N, leading to elevated tissue N concentration. While this pool of plant N may have benefits for saplings if light levels change, it may also increase the risk of herbivory by white-tailed deer (Odocoileus virginianus L.). We conducted a field fertilization experiment to test the hypothesis that saplings increase stem tissue N when soil N availability is elevated. We fertilized saplings of nine tree species under closed and open canopies. Two of the nine species, yellow birch (Betula alleghaniensis) and black cherry (Prunus serotina), had significant increases in radial growth when fertilized under high light. Six of the nine species showed increased stem N concentration under either low light or high light conditions. Under low light conditions, black cherry and sugar maple (Acer saccharum) had significantly higher concentrations of stem N when fertilized. Regardless of fertilization treatment, yellow birch had significantly greater stem N in saplings under low light conditions when compared with saplings found in high light conditions. Under high light conditions, fertilization resulted in increased stem N in saplings of white ash (Fraxinus americana) and eastern hemlock (Tsuga canadensis). There was a trend for saplings of red maple (Acer rubrum) and white ash to show elevated stem N concentration when fertilized under low light. Red oak (Quercus rubra), American beech (Fagus grandifolia) and white pine (Pinus strobus) did not show any evidence of luxury consumption. We compared browse frequency of fertilized and unfertilized saplings within similar forest types. Browse frequency was consistently higher on fertilized saplings. When averaged across all species, however, the difference between treatments was not significant. In contrast, we found significantly

  18. Improving the availability of emergency obstetric care in conflict-affected settings.

    PubMed

    Krause, S K; Meyers, J L; Friedlander, E

    2006-01-01

    This paper describes an emergency obstetric care (EmOC) project implemented by the Reproductive Health Response in Conflict (RHRC) Consortium in 12 conflict-affected settings in nine countries from 2000-2005 with funding and technical support from Columbia University's Mailman School of Public Health Averting Maternal Death and Disability (AMDD) programme. The overall goal of the project was to reduce maternal morbidity and mortality in select conflict-affected settings by improving the availability of EmOC. Another aim of the project was to institutionalize EmOC within RHRC Consortium agencies by modelling how to improve the availability of basic and comprehensive EmOC at clinics and hospitals. The specific project purpose was to increase the availability of EmOC in select conflict-affected settings. The project demonstrated that a great deal more can and should be done by humanitarian workers to improve the availability of basic and comprehensive emergency obstetric services in conflict-affected settings.

  19. A multicomponent strategy to improve the availability of antivenom for treating snakebite envenoming.

    PubMed

    Gutiérrez, José María; Burnouf, Thierry; Harrison, Robert A; Calvete, Juan J; Kuch, Ulrich; Warrell, David A; Williams, David J

    2014-07-01

    Snakebite envenoming is a common but neglected public health problem, particularly in impoverished rural regions of sub-Saharan Africa, Asia and Latin America. The only validated treatment for this condition is passive immunotherapy with safe and effective animal-derived antivenoms. However, there is a long-lasting crisis in the availability of these life-saving medications, particularly in sub-Saharan Africa and parts of Asia. We herein advocate a multicomponent strategy to substantially improve the availability of safe and effective antivenoms at the global level. This strategy is based on: (i) preparing validated collections of representative venom pools from the most medically dangerous snakes in high-risk regions of the world; (ii) strengthening the capacity of national antivenom manufacturing and quality control laboratories and their regulatory authorities and establishing new facilities in developing countries through technology transfer, as an integral part of efforts to develop their biological products industry; (iii) getting established laboratories to generate antivenoms for various regions of the world; and (iv) getting governments and relevant organizations to give snakebite envenoming due recognition within national and international public health policy frameworks. These ways of making antivenom available should be complemented by actions to improve health information systems, the accessibility of antivenoms, the training of medical and nursing staff, and community-based education. Such a multicomponent strategy involving stakeholders on many levels could help consolidate sustainable improvements in antivenom availability worldwide.

  20. 78 FR 44924 - Monsanto Co.; Availability of Plant Pest Risk Assessment, Environmental Assessment, Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which... products altered or produced through genetic engineering that are plant pests or that there is reason to...

  1. 76 FR 80871 - Monsanto Co.; Availability of Petition, Plant Pest Risk Assessment, and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ... 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which... products altered or produced through genetic engineering that are plant pests or that there is reason to...

  2. 78 FR 44926 - Monsanto Co.; Availability of Plant Pest Risk Assessment, Environmental Assessment, Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which... products altered or produced through genetic engineering that are plant pests or that there is reason to...

  3. 78 FR 32231 - Pioneer Hi-Bred International, Inc.; Availability of Plant Pest Risk Assessment, Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which... products altered or produced through genetic engineering that are plant pests or that there is reason to...

  4. Biotechnological Strategies to Improve Plant Biomass Quality for Bioethanol Production

    PubMed Central

    del Moral, Sandra; Núñez-López, Lizeth; Barrera-Figueroa, Blanca E.; Amaya-Delgado, Lorena

    2017-01-01

    The transition from an economy dependent on nonrenewable energy sources to one with higher diversity of renewables will not be a simple process. It requires an important research effort to adapt to the dynamics of the changing energy market, sort costly processes, and avoid overlapping with social interest markets such as food and livestock production. In this review, we analyze the desirable traits of raw plant materials for the bioethanol industry and the molecular biotechnology strategies employed to improve them, in either plants already under use (as maize) or proposed species (large grass families). The fundamentals of these applications can be found in the mechanisms by which plants have evolved different pathways to manage carbon resources for reproduction or survival in unexpected conditions. Here, we review the means by which this information can be used to manipulate these mechanisms for commercial uses, including saccharification improvement of starch and cellulose, decrease in cell wall recalcitrance through lignin modification, and increase in plant biomass. PMID:28951875

  5. Plant stomatal closure improves aphid feeding under elevated CO2.

    PubMed

    Sun, Yucheng; Guo, Huijuan; Yuan, Liang; Wei, Jianing; Zhang, Wenhao; Ge, Feng

    2015-01-10

    Stomata help plants regulate CO2 absorption and water vapor release in response to various environmental changes, and plants decrease their stomatal apertures and enhance their water status under elevated CO2 . Although the bottom-up effect of elevated CO2 on insect performance has been extensively studied, few reports have considered how insect fitness is altered by elevated CO2 -induced changes in host plant water status. We tested the hypothesis that aphids induce stomatal closure and increase host water potential, which facilitates their passive feeding, and that this induction can be enhanced by elevated CO2 . Our results showed that aphid infestation triggered the abscisic acid (ABA) signaling pathway to decrease the stomatal apertures of Medicago truncatula, which consequently decreased leaf transpiration and helped maintain leaf water potential. These effects increased xylem-feeding time and decreased hemolymph osmolarity, which thereby enhanced phloem-feeding time and increased aphid abundance. Furthermore, elevated CO2 up-regulated an ABA-independent enzyme, carbonic anhydrase, which led to further decrease in stomatal aperture for aphid-infested plants. Thus, the effects of elevated CO2 and aphid infestation on stomatal closure synergistically improved the water status of the host plant. The results indicate that aphid infestation enhances aphid feeding under ambient CO2 and that this enhancement is increased under elevated CO2 . © 2015 John Wiley & Sons Ltd.

  6. Classification and assessment models of first year byproducts nitrogen plant-availability from literature data.

    PubMed

    Joseph, Claude-Alla; Khiari, Lotfi; Gallichand, Jacques; Bouslama, Sidki

    2017-05-15

    Byproducts can provide an important amount of nutrients for crops and improve soils properties. According to their C/N, nitrogen (N) mineralization or immobilization may be observed after their application onto agricultural land. Therefore, an indicator is needed to assess byproducts N availability for crops. Thirty-seven studies from the scientific literature on N mineralization or immobilization after application to agricultural land under a wide range of climatic and experimental conditions were collected in order to elaborate models assessing non-composted byproducts N availability during the first growing season according to the C/N ratio. Four methods were used to evaluate N availability: incubation, apparent N recovery (ANR), relative N effectiveness (RNE) and fertilizer equivalence (FE). Since ANR was the model most related to C/N (R(2)=0.77), this model was used to define six categories of C/N. Results expressed in terms of FE were converted into RNE values. Although RNE is less precise than ANR, efficiencies of byproducts were expressed in terms of average RNE because it is the most appropriate for fertilization grids. Therefore, depending on C/N of non-composted byproducts, six categories were defined. i) high mineralization: +66% RNE and 5≤C/N, ii) moderate mineralization: +33% RNE and 5140.

  7. The availabilities of arsenic and cadmium in rice paddy fields from a mining area: The role of soil extractable and plant silicon.

    PubMed

    Yu, Huan-Yun; Ding, Xiaodong; Li, Fangbai; Wang, Xiangqin; Zhang, Shirong; Yi, Jicai; Liu, Chuanping; Xu, Xianghua; Wang, Qi

    2016-08-01

    Adequate silicon (Si) can greatly boost rice yield and improve grain quality through alleviating stresses associated with heavy metals and metalloids such as arsenic (As) and cadmium (Cd). The soil plant-available Si is relatively low in South China due to severe desilicification and allitization of the soils in this region. Conversely, pollution of heavy metals and metalloids in the soils of this region occurs widely, especially As and Cd pollution in paddy soil. Therefore, evaluating the plant availability of Si in paddy soil of South China and examining its correlation with the availability of heavy metals and metalloids are of great significance. Accordingly, in our study, 107 pairs of soil and rice plant samples were collected from paddy fields contaminated by As and Cd in South China. Significantly positive correlations between Si in rice plants and Si fractions in soils extracted with citric acid, NaOAc-HOAc buffer, and oxalate-ammonium oxalate buffer suggest that these extractants are more suitable for use in extracting plant-available Si in the soils of our present study. Significantly negative correlations between different Si fractions and As or Cd in rice plant tissues and negative exponential correlations between the molar ratios of Si to As/Cd in rice roots, straws, husks or grains and As/Cd in rice grains indicate that Si can significantly alleviate the accumulation of As/Cd from soils to the rice plants. Finally, a contribution assessment of soil properties to As/Cd accumulation in rice grains based on random forest showed that in addition to Si concentrations in soil or rice plants, other factors such as Fe fractions and total phosphorus also contributed largely to As/Cd accumulation in rice grains. Overall, Si exhibited its unique role in mitigating As or Cd stress in rice, and our study results provide strong field evidence for this role.

  8. Improving the Energy Efficiency of Pumped-Storage Power Plants

    SciTech Connect

    Artyukh, S. F.; Galat, V. V.; Kuz’min, V. V.; Chervonenko, I. I.; Shakaryan, Yu. G.; Sokur, P. V.

    2015-01-15

    Possible ways to improve the energy efficiency of hydroelectric generating sets of pumped-storage power plants (PSPPs) are studied. The Kiev PSPP is used as an example to show how its generating sets can be upgraded. It is concluded based on studies conducted that synchronous motor-generators should be replaced with asynchronized motor-generators. The feasibility of changing over the turbine to variable-speed operation is shown.

  9. Compressed Air System Modifications Improve Efficiency at a Plastics Blow Molding Plant (Southeastern Container Plant)

    SciTech Connect

    2001-06-01

    This case study is one in a series on industrial firms who are implementing energy efficient technologies and system improvements into their manufacturing processes. This case study documents the activities, savings, and lessons learned on the plastics blow molding plant project.

  10. Plant water potential improves prediction of empirical stomatal models.

    PubMed

    Anderegg, William R L; Wolf, Adam; Arango-Velez, Adriana; Choat, Brendan; Chmura, Daniel J; Jansen, Steven; Kolb, Thomas; Li, Shan; Meinzer, Frederick; Pita, Pilar; Resco de Dios, Víctor; Sperry, John S; Wolfe, Brett T; Pacala, Stephen

    2017-01-01

    Climate change is expected to lead to increases in drought frequency and severity, with deleterious effects on many ecosystems. Stomatal responses to changing environmental conditions form the backbone of all ecosystem models, but are based on empirical relationships and are not well-tested during drought conditions. Here, we use a dataset of 34 woody plant species spanning global forest biomes to examine the effect of leaf water potential on stomatal conductance and test the predictive accuracy of three major stomatal models and a recently proposed model. We find that current leaf-level empirical models have consistent biases of over-prediction of stomatal conductance during dry conditions, particularly at low soil water potentials. Furthermore, the recently proposed stomatal conductance model yields increases in predictive capability compared to current models, and with particular improvement during drought conditions. Our results reveal that including stomatal sensitivity to declining water potential and consequent impairment of plant water transport will improve predictions during drought conditions and show that many biomes contain a diversity of plant stomatal strategies that range from risky to conservative stomatal regulation during water stress. Such improvements in stomatal simulation are greatly needed to help unravel and predict the response of ecosystems to future climate extremes.

  11. Control of Seed Germination and Plant Development by Carbon and Nitrogen Availability

    PubMed Central

    Osuna, Daniel; Prieto, Pilar; Aguilar, Miguel

    2015-01-01

    Little is known about the molecular basis of the influence of external carbon/nitrogen (C/N) ratio and other abiotic factors on phytohormones regulation during seed germination and plant developmental processes, and the identification of elements that participate in this response is essential to understand plant nutrient perception and signaling. Sugars (sucrose, glucose) and nitrate not only act as nutrients but also as signaling molecules in plant development. A connection between changes in auxin transport and nitrate signal transduction has been reported in Arabidopsis thaliana through the NRT1.1, a nitrate sensor and transporter that also functions as a repressor of lateral root growth under low concentrations of nitrate by promoting auxin transport. Nitrate inhibits the elongation of lateral roots, but this effect is significantly reduced in abscisic acid (ABA)-insensitive mutants, what suggests that ABA might mediate the inhibition of lateral root elongation by nitrate. Gibberellin (GA) biosynthesis has been also related to nitrate level in seed germination and its requirement is determined by embryonic ABA. These mechanisms connect nutrients and hormones signaling during seed germination and plant development. Thus, the genetic identification of the molecular components involved in nutrients-dependent pathways would help to elucidate the potential crosstalk between nutrients, nitric oxide (NO) and phytohormones (ABA, auxins and GAs) in seed germination and plant development. In this review we focus on changes in C and N levels and how they control seed germination and plant developmental processes through the interaction with other plant growth regulators, such as phytohormones. PMID:26635847

  12. Reduced Wind Speed Improves Plant Growth in a Desert City

    PubMed Central

    Bang, Christofer; Sabo, John L.; Faeth, Stanley H.

    2010-01-01

    Background The often dramatic effects of urbanization on community and ecosystem properties, such as primary productivity, abundances, and diversity are now well-established. In most cities local primary productivity increases and this extra energy flows upwards to alter diversity and relative abundances in higher trophic levels. The abiotic mechanisms thought to be responsible for increases in urban productivity are altered temperatures and light regimes, and increased nutrient and water inputs. However, another abiotic factor, wind speed, is also influenced by urbanization and well known for altering primary productivity in agricultural systems. Wind effects on primary productivity have heretofore not been studied in the context of urbanization. Methodology/Principal Findings We designed a field experiment to test if increased plant growth often observed in cities is explained by the sheltering effects of built structures. Wind speed was reduced by protecting Encelia farinosa (brittlebush) plants in urban, desert remnant and outlying desert localities via windbreaks while controlling for water availability and nutrient content. In all three habitats, we compared E. farinosa growth when protected by experimental windbreaks and in the open. E. farinosa plants protected against ambient wind in the desert and remnant areas grew faster in terms of biomass and height than exposed plants. As predicted, sheltered plants did not differ from unprotected plants in urban areas where wind speed is already reduced. Conclusion/Significance Our results indicate that reductions in wind speed due to built structures in cities contribute to increased plant productivity and thus also to changes in abundances and diversity of higher trophic levels. Our study emphasizes the need to incorporate wind speed in future urban ecological studies, as well as in planning for green space and sustainable cities. PMID:20548790

  13. Availability of primary care team members can improve teamwork and readiness for change.

    PubMed

    Rodriguez, Hector P; Chen, Xiao; Martinez, Ana E; Friedberg, Mark W

    2016-01-01

    Early experiences of patient-centered medical home implementation indicate that redesigning primary care is an intensive organizational change that is most effectively undertaken by high-functioning interdisciplinary teams. Team effectiveness research indicates that consistent availability of team members and other aspects of team structure can impact teamwork and organizational outcomes. We conducted a survey of 766 adult primary care providers and staff in 34 California safety net practices to assess primary care team structure (team size, team member availability, and access to interdisciplinary expertise), teamwork, and readiness for change. We used path models with robust standard errors for clustering of respondents within practices to examine relationships between team member availability and readiness for change. Using path analysis, we examined the extent to which better teamwork mediated relationships between team member availability and readiness for change. We received 628 completed surveys (response rate = 82%). Greater team member availability was associated with greater readiness for change, but the relationship was stronger for staff than for primary care providers. Contrary to our hypothesis, path analyses revealed that the relationship of team member availability and greater readiness for change was only partially mediated (21%) by better teamwork. The direct effect of teamwork on readiness for change is approximately 2.9 times larger than the direct effect of team member availability on greater readiness for change. Ensuring that members perceive that their teammates are routinely available to them may improve readiness for implementing organizational changes like adopting patient-centered medical home models. Given that better teamwork only partially explained the availability-readiness relationship, additional research to identify the mechanisms through which consistent team member availability increases change readiness could lend insight into

  14. Performance of a commercially available plant allergen series in the assessment of suspected occupational contact dermatitis to plants in north Indian patients.

    PubMed

    De, Dipankar; Khullar, Geeti; Handa, Sanjeev

    2015-01-01

    Parthenium hysterophorus is the leading cause of phytogenic allergic contact dermatitis in India. The Indian Standard Series currently supplied by Systopic Laboratories Ltd and manufactured by Chemotechnique Diagnostics ® contains parthenolide as the only allergen representing plant allergens. The study was conducted to assess the performance of the Chemotechnique plant series (PL-1000), consisting of 14 allergens, in patients with clinically suspected occupational contact dermatitis to plant allergens. Ninety patients were patch tested with the Chemotechnique plant series from 2011 to 2013. Demographic details, clinical diagnosis and patch test results were recorded in the contact dermatitis clinic proforma. Of 90 patients, 24 (26.7%) showed positive reactions to one or more allergens in the plant series. Positive patch tests were elicited most commonly by sesquiterpene lactone mix in 19 (78.6%) patients, followed by parthenolide in 14 (57.1%), Achillea millefolium in 10 (42.9%) and others in decreasing order. The plant allergen series prepared by Chemotechnique Diagnostics is possibly not optimal for diagnosing suspected allergic contact dermatitis to plants in north Indians. Sesquiterpene lactone mix should replace parthenolide as the plant allergen in the Indian Standard Series until relevant native plant extracts are commercially available for patch testing.

  15. Phytochemical profile of commercially available food plant powders: their potential role in healthier food reformulations.

    PubMed

    Neacsu, M; Vaughan, N; Raikos, V; Multari, S; Duncan, G J; Duthie, G G; Russell, W R

    2015-07-15

    Reformulation of existing processed food or formulation of new foods using natural products (plant-based) will inherently confer to new products with less calories, fat, salt, phosphates and other synthetic components, and higher amounts of fibre, antioxidants, vitamins and other beneficial components. Plant ingredients, such as food plant powders, are currently being used in food manufacturing, predominantly for flavouring and colouring purposes. To expand their use as a food ingredient, freeze-dried powders representing major vegetable groups were characterised by targeted LC-MS/MS analysis of their phytochemicals. All the plant powders were found to be rich in flavonoids, phenolic acids and derivatives; total content in these compounds varied from around 130 mg kg(-1) (green pea) to around 930 mg kg(-1) (spinach). The food plant powders' phytochemical content represents valuable information for the food industry in the development of healthier novel foods and for the reformulation of existing food products in relation to antioxidants, food preservatives and alternatives to nitrite use. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Biochar increases plant available water in a sandy soil under an aerobic rice cropping system

    NASA Astrophysics Data System (ADS)

    de Melo Carvalho, M. T.; de Holanda Nunes Maia, A.; Madari, B. E.; Bastiaans, L.; van Oort, P. A. J.; Heinemann, A. B.; Soler da Silva, M. A.; Petter, F. A.; Meinke, H.

    2014-03-01

    The main objective of this study was to assess the impact of biochar rate (0, 8, 16 and 32 t ha-1) on the water retention capacity (WRC) of a sandy Dystric Plinthosol. The applied biochar was a by-product of slow pyrolysis (∼450 °C) of eucalyptus wood, milled to pass through a 2000 μm sieve that resulted in a material with an intrinsic porosity ≤10 μm and a specific surface area of ∼3.2 m2 g-1. The biochar was incorporated into the top 15 cm of the soil under an aerobic rice system. Our study focused on both the effects on WRC and rice yields at 2 and 3 years after application. Undisturbed soil samples were collected from 16 plots in two soil layers (5-10 and 15-20 cm). Soil water retention curves were modelled using a nonlinear mixed model which appropriately accounts for uncertainties inherent of spatial variability and repeated measurements taken within a specific soil sample. We found an increase in plant available water in the upper soil layer proportional to the rate of biochar, with about 0.8% for each t ha-1 of biochar amendment at 2 and 3 years after application. The impact of biochar on soil WRC was most likely related to an increase in overall porosity of the sandy soil, which was evident from an increase in saturated soil moisture and macro porosity with 0.5% and 1.6% for each t ha-1 of biochar applied, respectively. The increment in soil WRC did not translate into an increase in rice yield, essentially because in both seasons the amount of rainfall during critical period for rice production exceeded 650 mm. The use of biochar as a soil amendment can be a worthy strategy to guarantee yield stability under water limited conditions. Our findings raise the importance of assessing the feasibility of very high application rates of biochar and the inclusion of a detailed analysis of its physical and chemical properties as part of future investigations.

  17. Foraging activity of an Amazonian leaf-cutting ant: responses to changes in the availability of woody plants and to previous plant damage.

    PubMed

    Vasconcelos, H L

    1997-10-01

    This study investigates some factors affecting the foraging activity of the leaf-cutting ant Atta laevigata. The study was conducted on an abandoned farm near Manaus, in Brazilian Amazonia, where forest was beginning to regenerate. I determined how temporal changes in the structure of the woody plant community (linked to the regeneration process) affected the leaf harvesting activity of this Neotropical ant. A 0.39-ha plot was established, and woody plants existing and emerging in this plot were identified, tagged, measured and mapped. At intervals of approximately 14 days all marked plants were checked to determine which had been attacked by A. laevigata during that period. Woody plant density doubled over the 18-months of the study. However, the number of plants attacked by A. laevigata, controlling for seasonal differences in ant activity, was independent of the number available for attack. The number of plants attacked was also independent of the number of new plants emerged in the previous 2 months. Apart from changes in total plant density, the relative abundance of most species also changed with time. Data on the composition of the plant community and on the composition of the ants' diet at different time intervals were subject to ordination analysis. The analyses revealed that successional changes in the composition of the woody plant community did significantly affect the composition of the leaf diet of A. laevigata. Variations in the ants' diet correlated most strongly with variations in the abundance of Bellucia imperialis. As this increased in abundance its relative contribution to the ants' diet increased. In addition, I observed a small decline in the diversity of plant resources exploited by the ants. B. imperialis was one of the species most preferred by A. laevigata, suggesting that variations in the diversity of its diet were related to the abundance of preferred species. The chances of an individual plant being attacked was independent of

  18. 77 FR 21993 - Endangered and Threatened Wildlife and Plants; Notice of Availability of a Technical/Agency Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... Fish and Wildlife Service Endangered and Threatened Wildlife and Plants; Notice of Availability of a Technical/Agency Draft Recovery Plan for Alabama Sturgeon AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of availability and request for public comment. SUMMARY: We, the Fish and Wildlife Service...

  19. Competitive interactions between established grasses and woody plant seedlings under elevated CO₂ levels are mediated by soil water availability.

    PubMed

    Manea, A; Leishman, M R

    2015-02-01

    The expansion of woody plants into grasslands has been observed worldwide and is likely to have widespread ecological consequences. One proposal is that woody plant expansion into grasslands is driven in part by the rise in atmospheric CO2 concentrations. We have examined the effect of CO2 concentration on the competitive interactions between established C4 grasses and woody plant seedlings in a model grassland system. Woody plant seedlings were grown in mesocosms together with established C4 grasses in three competition treatments (root competition, shoot competition and root + shoot competition) under ambient and elevated CO2 levels. We found that the growth of the woody plant seedlings was suppressed by competition from grasses, with root and shoot competition having similar competitive effects on growth. In contrast to expectations, woody plant seedling growth was reduced at elevated CO2 levels compared to that at the ambient CO2 level across all competition treatments, with the most plausible explanation being reduced light and soil water availability in the elevated CO2 mesocosms. Reduced light and soil water availability in the elevated CO2 mesocosms was associated with an increased leaf area index of the grasses which offset the reductions in stomatal conductance and increased rainfall interception. The woody plant seedlings also had reduced 'escapability' (stem biomass and stem height) under elevated compared to ambient CO2 levels. Our results suggest that the expansion of woody plants into grasslands in the future will likely be context-dependent, with the establishment success of woody plant seedlings being strongly coupled to the CO2 response of competing grasses and to soil water availability.

  20. Biomass, Leaf Area, and Resource Availability of Kudzu Dominated Plant Communities Following Herbicide Treatment

    SciTech Connect

    L.T. Rader

    2001-10-01

    Kudzu is an exotic vine that threatens the forests of the southern U.S. Five herbicides were tested with regard to their efficacy in controlling kudzu, community recover was monitored, and interactions with planted pines were studied. The sites selected were old farm sites dominated by kudzu.These were burned following herbicide treatment. The herbicides included triclopyr, clopyralid, metsulfuron, tebuthiuron, and picloram plus 2,4-D. Pine seedlings were planted the following year. Regression equations were developed for predicting biomass and leaf area. Four distinct plant communities resulted from the treatments. The untreated check continued to be kudzu dominated. Blackberry dominated the clopyradid treatment. Metsulfron, trychlopyr and picloram treated sites resulted in herbaceous dominated communities. The tebuthiuron treatment maintained all vegetation low.

  1. Soil microbial communities are shaped by plant-driven changes in resource availability during secondary succession.

    PubMed

    Cline, Lauren C; Zak, Donald R

    2015-12-01

    Although we understand the ecological processes eliciting changes in plant community composition during secondary succession, we do not understand whether co-occurring changes in plant detritus shape saprotrophic microbial communities in soil. In this study, we investigated soil microbial composition and function across an old-field chronosequence ranging from 16 to 86 years following agricultural abandonment, as well as three forests representing potential late-successional ecosystems. Fungal and bacterial community composition was quantified from ribosomal DNA, and insight into the functional potential of the microbial community to decay plant litter was gained from shotgun metagenomics and extracellular enzyme assays. Accumulation of soil organic matter across the chronosequence exerted a positive and significant effect on fungal phylogenetic β-diversity and the activity of extracellular enzymes with lignocellulolytic activity. In addition, the increasing abundance of lignin-rich C4 grasses was positively related to the composition of fungal genes with lignocellulolytic function, thereby linking plant community composition, litter biochemistry, and microbial community function. However, edaphic properties were the primary agent shaping bacterial communities, as bacterial β-diversity and variation in functional gene composition displayed a significant and positive relationship to soil pH across the chronosequence. The late-successional forests were compositionally distinct from the oldest old fields, indicating that substantial changes occur in soil microbial communities as old fields give way to forests. Taken together, our observations demonstrate that plants govern the turnover of soil fungal communities and functional characteristics during secondary succession, due to the continual input of detritus and differences in litter biochemistry among plant species.

  2. Larval food plants of Australian Larentiinae (Lepidoptera: Geometridae) - a review of available data

    PubMed Central

    2016-01-01

    Abstract Background In Australia, the subfamily Larentiinae (Lepidoptera: Geometridae) comprises over 45 genera with about 270 species described so far. However, life histories of the Australian larentiine moths have barely been studied. New information The current paper presents a list of larval food plants of 51 Australian larentiine species based on literature references, data from specimen labels and own observations. Some Australian habitats are shown. Possible relationships among the taxa based on food preference of the larvae are discussed. Additionally, a list of Australasian larentiine species from the genera occurring in Australia and their food plants is presented. PMID:27099558

  3. Soil microbial properties and plant growth responses to carbon and water addition in a temperate steppe: the importance of nutrient availability.

    PubMed

    Ma, Linna; Huang, Wenwen; Guo, Chengyuan; Wang, Renzhong; Xiao, Chunwang

    2012-01-01

    Global climatic change is generally expected to stimulate net primary production, and consequently increase soil carbon (C) input. The enhanced C input together with potentially increased precipitation may affect soil microbial processes and plant growth. To examine the effects of C and water additions on soil microbial properties and plant growth, we conducted an experiment lasting two years in a temperate steppe of northeastern China. We found that soil C and water additions significantly affected microbial properties and stimulated plant growth. Carbon addition significantly increased soil microbial biomass and activity but had a limited effect on microbial community structure. Water addition significantly increased soil microbial activity in the first year but the response to water decreased in the second year. The water-induced changes of microbial activity could be ascribed to decreased soil nitrogen (N) availability and to the shift in soil microbial community structure. However, no water effect on soil microbial activity was visible under C addition during the two years, likely because C addition alleviated nutrient limitation of soil microbes. In addition, C and water additions interacted to affect plant functional group composition. Water addition significantly increased the ratio of grass to forb biomass in C addition plots but showed only minor effects under ambient C levels. Our results suggest that soil microbial activity and plant growth are limited by nutrient (C and N) and water availability, and highlight the importance of nutrient availability in modulating the responses of soil microbes and plants to potentially increased precipitation in the temperate steppe. Increased soil C input and precipitation would show significant effects on soil microbial properties and plant growth in the temperate steppe. These findings will improve our understanding of the responses of soil microbes and plants to the indirect and direct climate change effects.

  4. Improvements in plant growth rate using underwater discharge

    NASA Astrophysics Data System (ADS)

    Takaki, K.; Takahata, J.; Watanabe, S.; Satta, N.; Yamada, O.; Fujio, T.; Sasaki, Y.

    2013-03-01

    The drainage water from plant pots was irradiated by plasma and then recycled to irrigate plants for improving the growth rate by supplying nutrients to plants and inactivating the bacteria in the bed-soil. Brassica rapa var. perviridis (Chinese cabbage; Brassica campestris) plants were cultivated in pots filled with artificial soil, which included the use of chicken droppings as a fertiliser. The water was recycled once per day from a drainage water pool and added to the bed-soil in the pots. A magnetic compression type pulsed power generator was used to produce underwater discharge with repetition rate of 250 pps. The plasma irradiation times were set as 10 and 20 minutes per day over 28 days of cultivation. The experimental results showed that the growth rate increased significantly with plasma irradiation into the drainage water. The growth rate increased with the plasma irradiation time. The nitrogen concentration of the leaves increased as a result of plasma irradiation based on chlorophyll content analysis. The bacteria in the drainage water were inactivated by the plasma irradiation.

  5. Acclimation improves salt stress tolerance in Zea mays plants.

    PubMed

    Pandolfi, Camilla; Azzarello, Elisa; Mancuso, Stefano; Shabala, Sergey

    2016-08-20

    Plants exposure to low level salinity activates an array of processes leading to an improvement of plant stress tolerance. Although the beneficial effect of acclimation was demonstrated in many herbaceous species, underlying mechanisms behind this phenomenon remain poorly understood. In the present study we have addressed this issue by investigating ionic mechanisms underlying the process of plant acclimation to salinity stress in Zea mays. Effect of acclimation were examined in two parallel sets of experiments: a growth experiment for agronomic assessments, sap analysis, stomatal conductance, chlorophyll content, and confocal laser scanning imaging; and a lab experiment for in vivo ion flux measurements from root tissues. Being exposed to salinity, acclimated plants (1) retain more K(+) but accumulate less Na(+) in roots; (2) have better vacuolar Na(+) sequestration ability in leaves and thus are capable of accumulating larger amounts of Na(+) in the shoot without having any detrimental effect on leaf photochemistry; and (3) rely more on Na(+) for osmotic adjustment in the shoot. At the same time, acclimation affect was not related in increased root Na(+) exclusion ability. It appears that even in a such salt-sensitive species as maize, Na(+) exclusion from uptake is of a much less importance compared with the efficient vacuolar Na(+) sequestration in the shoot. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Characteristics of information available on fire and invasive plants in the eastern United States

    Treesearch

    Corey L. Gucker; Kris Zouhar; Jane Kapler Smith; Katharine R. Stone

    2012-01-01

    Wildland managers need detailed information about the responses of invasive species to fire and the conditions that increase site invasibility in order to effectively manage fire without introducing or increasing populations of invasive plants. Literature reviews and syntheses of original research are important sources of this information, but the usefulness of a...

  7. Effect of Nitrogen Availability on Mineral Nutrient Uptake and Plant Growth of Container-Grown Hydrangeas

    USDA-ARS?s Scientific Manuscript database

    Rooted liners of Hydrangea macrophylla 'Red Star' were fertigated with one of three nitrogen (N) concentrations (0, 140, or 280 ppm) in a modified Hoagland’s solution from June to November. Every 3 weeks starting in June, plants in each N treatment (0N, 140N, 280N) were destructively harvested to de...

  8. Multitrophic effects of calcium availability on invasive alien plants, birds, and bird prey items

    Treesearch

    Vince D' Amico; Greg Shriver; Jake Bowman; Meg Ballard; Whitney Wiest; Liz Tymkiw; Melissa. Miller

    2011-01-01

    Acid rain alters forest soil calcium concentrations in two ways: (1) hydrogen ions displace exchangeable calcium adsorbed to soil surfaces, and (2) aluminum is released to soil water by acid rain and displaces adsorbed calcium. This increases the absorption of aluminum by plant roots, and decreases the absorption of calcium, causing calcium to be more readily leached...

  9. Evaluation of H3A for determination of plant available P vs. FeAIO strips

    USDA-ARS?s Scientific Manuscript database

    Phosphorus is an essential nutrient for plant growth but in excess is a source of environmental pollution. Fertilizer additions of P are recommended based on soil tests; however, the commonly applied P extractants are often applied outside of their design criteria (specifically soil pH). As a resu...

  10. Soil Phosphatase Activity and Plant-available Phosphorus Increase Following Grassland Invasion by N-fixing Tree Legumes

    NASA Astrophysics Data System (ADS)

    Boutton, T. W.; Kantola, I. B.; Stott, D. E.; Balthrop, S. L.; Tribble, J. E.; Filley, T. R.

    2009-12-01

    Grass-dominated ecosystems around the world are experiencing woody plant invasion due to human land uses. Vast regions in southern Texas have been transformed from open grasslands to subtropical thorn woodlands during the past 150 yrs. These woodlands are dominated by N-fixing tree legumes which are more productive above- and belowground, and store 2-3X more C and N than remnant grasslands. In tropical savannas and forests, it has been demonstrated that N-fixing plants are able to invest additional N in the acquisition of soil P. Accordingly, we hypothesized that soil acid phosphatase (AP) enzyme activity and concentrations of plant-available soil P (largely HPO4-2 and H2PO4-) would be greater in wooded areas dominated by N-fixing trees than in remnant grasslands where N-fixers are absent. We collected soils (0-7.5 cm) in remnant grasslands and in each of 4 different woodland types (clusters, groves, drainage woodlands, and playas) in a savanna parkland landscape in southern Texas. Plant-available soil P was determined by sorption onto anion exchange resin membranes placed in soil-water mixtures and shaken for 16 hr. P was desorbed from resin membranes using 0.5 N HCl and quantified colorimetrically using the Murphy-Riley technique. AP activity was determined using para-nitrophenyl phosphate as an analogue orthophosphate substrate, and then quantifying the p-nitrophenol (pNP) reaction product. AP activity was 250 µg pNP/g soil/hr in grasslands, and increased linearly with time following woody plant invasion to 1400 µg pNP/g soil/hr in the oldest woody plant assemblages (90 yrs). Plant available P was 3 mg P/kg soil in grasslands, and ranged from 10 to 45 mg P/kg soil in wooded areas. Within each of the wooded landscape types, plant-available P increased linearly with time following woody invasion and was correlated with soil AP activity. Results are consistent with prior studies showing that AP and plant-available P are elevated under canopies of N-fixing plants

  11. Plant Community Responses to Simultaneous Changes in Temperature, Nitrogen Availability, and Invasion

    PubMed Central

    Gornish, Elise S.; Miller, Thomas E.

    2015-01-01

    Background Increasing rates of change in climate have been observed across the planet and have contributed to the ongoing range shifts observed for many species. Although ecologists are now using a variety of approaches to study how much and through what mechanisms increasing temperature and nutrient pollution may influence the invasions inherent in range shifts, accurate predictions are still lacking. Methods and Results In this study, we conducted a factorial experiment, simultaneously manipulating warming, nitrogen addition and introduction of Pityopsis aspera, to determine how range-shifting species affect a plant community. We quantified the resident community using ordination scores, then used structural equation modeling to examine hypotheses related to how plants respond to a network of experimental treatments and environmental variables. Variation in soil pH explained plant community response to nitrogen addition in the absence of invasion. However, in the presence of invasion, the direct effect of nitrogen on the community was negligible and soil moisture was important for explaining nitrogen effects. We did not find effects of warming on the native plant community in the absence of invasion. In the presence of invasion, however, warming had negative effects on functional richness directly and invasion and herbivory explained the overall positive effect of warming on the plant community. Conclusions and Significance This work highlights the variation in the biotic and abiotic factors responsible for explaining independent and collective climate change effects over a short time scale. Future work should consider the complex and non-additive relationships among factors of climate change and invasion in order to capture more ecologically relevant features of our changing environment. PMID:25879440

  12. Plant community responses to simultaneous changes in temperature, nitrogen availability, and invasion.

    PubMed

    Gornish, Elise S; Miller, Thomas E

    2015-01-01

    Increasing rates of change in climate have been observed across the planet and have contributed to the ongoing range shifts observed for many species. Although ecologists are now using a variety of approaches to study how much and through what mechanisms increasing temperature and nutrient pollution may influence the invasions inherent in range shifts, accurate predictions are still lacking. In this study, we conducted a factorial experiment, simultaneously manipulating warming, nitrogen addition and introduction of Pityopsis aspera, to determine how range-shifting species affect a plant community. We quantified the resident community using ordination scores, then used structural equation modeling to examine hypotheses related to how plants respond to a network of experimental treatments and environmental variables. Variation in soil pH explained plant community response to nitrogen addition in the absence of invasion. However, in the presence of invasion, the direct effect of nitrogen on the community was negligible and soil moisture was important for explaining nitrogen effects. We did not find effects of warming on the native plant community in the absence of invasion. In the presence of invasion, however, warming had negative effects on functional richness directly and invasion and herbivory explained the overall positive effect of warming on the plant community. This work highlights the variation in the biotic and abiotic factors responsible for explaining independent and collective climate change effects over a short time scale. Future work should consider the complex and non-additive relationships among factors of climate change and invasion in order to capture more ecologically relevant features of our changing environment.

  13. Plant exomics: Concepts, applications and methodologies in crop improvement

    PubMed Central

    Hashmi, Uzair; Shafqat, Samia; Khan, Faria; Majid, Misbah; Hussain, Harris; Kazi, Alvina Gul; John, Riffat; Ahmad, Parvaiz

    2015-01-01

    Molecular breeding has a crucial role in improvement of crops. Conventional breeding techniques have failed to ameliorate food production. Next generation sequencing has established new concepts of molecular breeding. Exome sequencing has proven to be a significant tool for assessing natural evolution in plants, studying host pathogen interactions and betterment of crop production as exons assist in interpretation of allelic variation with respect to their phenotype. This review covers the platforms for exome sequencing, next generation sequencing technologies that have revolutionized exome sequencing and led toward development of third generation sequencing. Also discussed in this review are the uses of these sequencing technologies to improve wheat, rice and cotton yield and how these technologies are used in exploring the biodiversity of crops, providing better understanding of plant-host pathogen interaction and assessing the process of natural evolution in crops and it also covers how exome sequencing identifies the gene pool involved in symbiotic and other co-existential systems. Furthermore, we conclude how integration of other methodologies including whole genome sequencing, proteomics, transcriptomics and metabolomics with plant exomics covers the areas which are left untouched with exomics alone and in the end how these integration will transform the future of crops. PMID:25482786

  14. Application of Lean Methodology for Improved Quality and Efficiency in Operating Room Instrument Availability.

    PubMed

    Farrokhi, Farrokh R; Gunther, Maria; Williams, Barbara; Blackmore, Christopher Craig

    2015-01-01

    Advances in surgical instrumentation allow surgeons to treat patients with less morbidity and shorter recovery time. However, the increasing complexity also adds to surgical risk, and to operating room supply chain burden. To improve the quality and efficiency of operating room instrument availability, we developed and validated a Lean 5S approach consisting of sort (determining instrument usage and waste), simplify (removing unnecessary instruments), sweep (confirm availability of needed instruments), standardize (all trays the same for a given procedure), and self-discipline (monitor success). The primary outcome was reduction in unnecessary instruments delivered to the operating room. As a secondary analysis, we evaluated the effect of the Lean instrument intervention on surgery times. We reduced the number of instruments for minimally invasive spine surgery by 70% (from 197 to 58), and setup time decreased 37% (13.1-8.2 min, p = .0015). We also report subsequent validation of the approach on deep brain stimulator cases. We conclude that complex surgical procedures offer opportunities for substantial waste reduction, simplification, and quality improvement, with potential institutional annual cost savings of $2.8 million. We demonstrate that Lean methodology can improve quality at lower cost.

  15. Negative interactive effects between biochar and phosphorus fertilization on phosphorus availability and plant yield in saline sodic soil.

    PubMed

    Xu, Gang; Zhang, You; Sun, Junna; Shao, Hongbo

    2016-10-15

    Little is known about the interactive effects between biochar application and phosphorus (P) fertilization on plant growth and P uptake. For this purpose, five wheat straw biochars (produced at 25°C, 300°C, 400°C, 500°C and 600°C for 4h) with equal P (36mgkg(-1)) amount, with and without additional P fertilization (100mgkg(-1)) were applied in a pot experiment to investigate the growth of Suaeda salsa and their uptake of P from biochar and P fertilization amended saline sodic soil. Soil P fractions, dry matter yield, and plant P concentrations were determined after harvesting 90days. Our results confirmed that relatively lower pyrolysis temperature (<400°C) biochar retained P availability and increased plant growth. The plant P concentration was significantly correlated with NaHCO3-Pi (P<0.05), and NaOH-Pi (P<0.1) during early incubation time (4days) for biochar amended soil. As revealed by statistical analysis, a significant (P<0.05) negative (antagonistic) interaction occurred between biochar and P fertilization on the biomass production and plant P concentration. For plant biomass, the effects size of biochar (B), P, and their interaction followed the order of B×P (0.819)>B (0.569)≈P (0.568) based on the partial Eta squared values whereas the order changed as P (0.782)>B (0.562)>B×P (0.515) for plant P concentration. When biochar and P fertilization applied together, phosphate precipitation/sorption reaction occurred in saline sodic soil which explained the decreased plant P availability and plant yield in saline sodic soil. The negative interaction effects between biochar and P fertilization indicated limited utility value of biochar application in saline sodic soil. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Therapeutic Education in Improving Cancer Pain Management: A Synthesis of Available Studies.

    PubMed

    Prevost, Virginie; Delorme, Claire; Grach, Marie-Christine; Chvetzoff, Gisèle; Hureau, Magalie

    2016-07-01

    This literature review aims to synthesize available studies and to update findings in order to obtain a current, comprehensive estimate of the benefits of pain education. Forty-four original articles obtained from the PubMed database were analyzed to investigate which protocols could be most effective in improving pain management. Recent studies indicate a growing interest in evaluating patients' skills and attitudes; these include satisfaction with cancer pain treatment, patient-reported improvement, and patient participation-all of which could be dependable benchmarks for evaluating the effectiveness of educational programs. Besides pain measurement, recent studies advance support for the importance of assessing newly developed outcome criteria. In this sense, patients' active participation and decision making in their pain management are probably the most relevant goals of pain education. © The Author(s) 2015.

  17. In vitro thrombolytic potential of root extracts of four medicinal plants available in Bangladesh

    PubMed Central

    Hussain, Fahad; Islam, Ariful; Bulbul, Latifa; Moghal, Mizanur Rahman; Hossain, Mohammad Salim

    2014-01-01

    Context: Thrombus formation inside the blood vessels obstructs blood flow through the circulatory system leading hypertension, stroke to the heart, anoxia, and so on. Thrombolytic drugs are widely used for the management of cerebral venous sinus thrombosis patients, but they have certain limitations. Medicinal plants and their components possessing antithrombotic activity have been reported before. However, plants that could be used for thrombolysis has not been reported so far. Aims: This study's aim was to evaluate the thrombolytic potential of selected plants’ root extracts. Settings and Design: Plants were collected, dried, powdered and extracted by methanol and then fractionated by n-hexane for getting the sample root extracts. Venous blood samples were drawn from 10 healthy volunteers for the purposes of investigation. Subjects and Methods: An in vitro thrombolytic model was used to check the clot lysis potential of four n-hexane soluble roots extracts viz., Acacia nilotica, Justicia adhatoda, Azadirachta indica, and Lagerstroemia speciosa along with streptokinase as a positive control and saline water as a negative control. Statistical Analysis Used: Dunnett t-test analysis was performed using SPSS is a statistical analysis program developed by IBM Corporation, USA. on Windows. Results: Using an in vitro thrombolytic model, A. nilotica, L. speciosa, A. indica, and J. adhatoda at 5 mg extract/ml NaCl solution concentration showed 15.1%, 15.49%, 21.26%, and 19.63% clot lysis activity respectively. The reference streptokinase showed 47.21%, and 24.73% clot lysis for 30,000 IU and 15,000 IU concentrations, respectively whereas 0.9% normal saline showed 5.35% clot lysis. Conclusions: The selected extracts of the plant roots possess marked thrombolytic properties that could lyse blood clots in vitro; however, in vivo clot dissolving properties and active components responsible for clot lysis are yet to be discovered. PMID:25538351

  18. Hanford Waste Vitrification Plant technical background document for toxics best available control technology demonstration

    SciTech Connect

    1992-10-01

    This document provides information on toxic air pollutant emissions to support the Notice of Construction for the proposed Hanford Waste Vitrification Plant (HWVP) to be built at the the Department of Energy Hanford Site near Richland, Washington. Because approval must be received prior to initiating construction of the facility, state and federal Clean Air Act Notices of construction are being prepared along with necessary support documentation.

  19. EARLY ENTRANCE CO-PRODUCTION PLANT - DECENTRALIZED GASIFICATION COGENERATION TRANSPORTATION FUELS AND STEAM FROM AVAILABLE FEEDSTOCKS

    SciTech Connect

    Unknown

    2002-06-01

    Waste Processors Management, Inc. (WMPI), along with its subcontractors entered into a Cooperative Agreement with the USDOE, National Energy Technology Laboratory (NETL) to assess the techno-economic viability of building an Early Entrance Co-Production Plant (EECP) in the US to produce ultra clean Fischer-Tropsch (FT) transportation fuels with either power or steam as the major co-product. The EECP design includes recovery and gasification of low-cost coal waste (culm) from physical coal cleaning operations and will assess blends of the culm with coal or petroleum coke. The project has three phases. Phase 1 is the concept definition and engineering feasibility study to identify areas of technical, environmental and financial risk. Phase II is an experimental testing program designed to validate the coal waste mixture gasification performance. Phase III updates the original EECP design based on results from Phase II, to prepare a preliminary engineering design package and financial plan for obtaining private funding to build a 5,000 barrel per day (BPD) coal gasification/liquefaction plant next to an existing co-generation plant in Gilberton, Schuylkill County, Pennsylvania. The current report is WMPI's fourth quarterly technical progress report. It covers the period performance from January 1, 2002 through March 31, 2002.

  20. EARLY ENTRANCE CO-PRODUCTION PLANT - DECENTRALIZED GASIFICATION COGENERATION TRANSPORTATION FUELS AND STEAM FROM AVAILABLE FEEDSTOCKS

    SciTech Connect

    Unknown

    2001-12-01

    Waste Processors Management, Inc. (WMPI), along with its subcontractors Texaco Power & Gasification, SASOL Technology Ltd., and Nexant Inc. entered into a Cooperative Agreement DE-FC26-00NT40693 with the US Department of Energy (DOE), National Energy Technology Laboratory (NETL) to assess the techno-economic viability of building an Early Entrance Co-Production Plant (EECP) in the US to produce ultra clean Fischer-Tropsch (FT) transportation fuels with either power or steam as the major co-product. The EECP designs emphasize on recovery and gasification of low-cost coal waste (culm) from coal clean operations and will assess blends of the culm and coal or petroleum coke as feedstocks. The project is being carried out in three phases. Phase I involves definition of concept and engineering feasibility study to identify areas of technical, environmental and financial risk. Phase II consists of an experimental testing program designed to validate the coal waste mixture gasification performance. Phase III involves updating the original EECP design, based on results from Phase II, to prepare a preliminary engineering design package and financial plan for obtaining private funding to build a 5,000 BPD coal gasification/liquefaction plant next to an existing co-generation plant in Gilberton, Schuylkill County, Pennsylvania.

  1. EARLY ENTRANCE CO-PRODUCTION PLANT - DECENTRALIZED GASIFICATION COGENERATION TRANSPORTATION FUELS AND STEAM FROM AVAILABLE FEEDSTOCKS

    SciTech Connect

    Unknown

    2003-01-01

    Waste Processors Management, Inc. (WMPI), along with its subcontractors Texaco Power & Gasification (now ChevronTexaco), SASOL Technology Ltd., and Nexant Inc. entered into a Cooperative Agreement DE-FC26-00NT40693 with the U. S. Department of Energy (DOE), National Energy Technology Laboratory (NETL) to assess the technoeconomic viability of building an Early Entrance Co-Production Plant (EECP) in the United States to produce ultra clean Fischer-Tropsch (FT) transportation fuels with either power or steam as the major co-product. The EECP design includes recovery and gasification of low-cost coal waste (culm) from physical coal cleaning operations and will assess blends of the culm with coal or petroleum coke. The project has three phases. Phase I is the concept definition and engineering feasibility study to identify areas of technical, environmental and financial risk. Phase II is an experimental testing program designed to validate the coal waste mixture gasification performance. Phase III updates the original EECP design based on results from Phase II, to prepare a preliminary engineering design package and financial plan for obtaining private funding to build a 5,000 barrel per day (BPD) coal gasification/liquefaction plant next to an existing co-generation plant in Gilberton, Schuylkill County, Pennsylvania. The current report covers the period performance from July 1, 2002 through September 30, 2002.

  2. Suggested improvements for the allergenicity assessment of genetically modified plants used in foods.

    PubMed

    Goodman, Richard E; Tetteh, Afua O

    2011-08-01

    Genetically modified (GM) plants are increasingly used for food production and industrial applications. As the global population has surpassed 7 billion and per capita consumption rises, food production is challenged by loss of arable land, changing weather patterns, and evolving plant pests and disease. Previous gains in quantity and quality relied on natural or artificial breeding, random mutagenesis, increased pesticide and fertilizer use, and improved farming techniques, all without a formal safety evaluation. However, the direct introduction of novel genes raised questions regarding safety that are being addressed by an evaluation process that considers potential increases in the allergenicity, toxicity, and nutrient availability of foods derived from the GM plants. Opinions vary regarding the adequacy of the assessment, but there is no documented proof of an adverse effect resulting from foods produced from GM plants. This review and opinion discusses current practices and new regulatory demands related to food safety.

  3. The roles of nematodes in nitrogen and phosphorous availability, plant uptake and growth in organically amended soils

    NASA Astrophysics Data System (ADS)

    Gebremikael, Mesfin; Buchan, David; De Neve, Stefaan

    2017-04-01

    Several studies have shown that soil biota contributes significantly to the crucial ecosystem functions and services such as organic matter decomposition and nutrient cycling. The contribution of each group of soil organisms may vary depending primarily on their feeding behavior. The magnitude of the ecosystem services by the biota may also depend on the interactions amongst the soil biota groups and their surrounding environment, for instance, biochemical characteristics of the externally added organic material. However, only a few studies considered these interactions concurrently. Here, we investigated the effects of fauna-microbe-plant interactions on organic matter decomposition and nutrient cycling by applying different organic materials spanning a range of C:N ratios and presumed N availability. Nematodes were selected as model fauna because they are the most abundant soil metazoans that have a diversified feeding strategy and interact very intimately with microbes, other fauna, and plants. A series of incubation experiments were conducted in bare and planted microcosms under controlled conditions using fresh soil collected from an agricultural field and defaunated by gamma irradiation. In the first experiment without plants, the defaunated soil cores were either left unamended (UNA) or received lignin-rich low N compost (COI), N-rich compost (COV), fresh manure (MAN) or chopped clover (CLO). The entire free-living soil nematode community was extracted from unirradiated fresh soil and reinoculated into half of the soil cores that had been defaunated by gamma irradiation. Two treatments: with (+Nem) and without (-Nem) nematodes were compared for soil nitrogen and phosphorus availability, plant uptake, and PLFA signatures over time during a 105-days incubation. The same experimental setup was used to investigate further the CLO amendment in the presence of plants (rye grass was used as a model plant). Nematodes were extracted and assigned to feeding groups

  4. Improving phosphorus availability in an acid soil using organic amendments produced from agroindustrial wastes.

    PubMed

    Ch'ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab

    2014-01-01

    In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus), and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.

  5. Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes

    PubMed Central

    Ch'ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab.

    2014-01-01

    In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus), and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments. PMID:25032229

  6. Using Participatory Approach to Improve Availability of Spatial Data for Local Government

    NASA Astrophysics Data System (ADS)

    Kliment, T.; Cetl, V.; Tomič, H.; Lisiak, J.; Kliment, M.

    2016-09-01

    Nowadays, the availability of authoritative geospatial features of various data themes is becoming wider on global, regional and national levels. The reason is existence of legislative frameworks for public sector information and related spatial data infrastructure implementations, emergence of support for initiatives as open data, big data ensuring that online geospatial information are made available to digital single market, entrepreneurs and public bodies on both national and local level. However, the availability of authoritative reference spatial data linking the geographic representation of the properties and their owners are still missing in an appropriate quantity and quality level, even though this data represent fundamental input for local governments regarding the register of buildings used for property tax calculations, identification of illegal buildings, etc. We propose a methodology to improve this situation by applying the principles of participatory GIS and VGI used to collect observations, update authoritative datasets and verify the newly developed datasets of areas of buildings used to calculate property tax rates issued to their owners. The case study was performed within the district of the City of Požega in eastern Croatia in the summer 2015 and resulted in a total number of 16072 updated and newly identified objects made available online for quality verification by citizens using open source geospatial technologies.

  7. A new grading system for plant-available potassium using exhaustive cropping techniques combined with chemical analyses of soils

    PubMed Central

    Li, Ting; Wang, Huoyan; Zhou, Zijun; Chen, Xiaoqin; Zhou, Jianmin

    2016-01-01

    A new grading system for plant-available potassium (K) in soils based on K release rate from soils and plant growth indices was established. In the study, fourteen different agricultural soils from the southern subtropical to the northern temperate zones in China were analyzed by both chemical extraction methods and exhaustive cropping techniques. Based on the change trends in plant growth indices, relative biomass yields of 70% and 50%, K-deficient coefficients of 35 and 22 under conventional exhaustive experiments, and tissue K concentrations of 40 g kg−1 and 15 g kg−1 under intensive exhaustive experiments were obtained as critical values that represent different change trends. In addition, the extraction method using 0.2 mol L−1 sodium tetraphenylboron (NaTPB) suggested soil K release rates of 12 mg kg−1 min−1 and 0.4 mg kg−1 min−1 as turning points that illustrated three different release trends. Thus, plant-available K in soils was classified into three categories: high available K, medium available K and low available K, and grading criteria and measurement methods were also proposed. This work has increased our understanding of soil K bioavailability and has direct application in terms of routine assessment of agriculture soils. PMID:27876838

  8. A new grading system for plant-available potassium using exhaustive cropping techniques combined with chemical analyses of soils

    NASA Astrophysics Data System (ADS)

    Li, Ting; Wang, Huoyan; Zhou, Zijun; Chen, Xiaoqin; Zhou, Jianmin

    2016-11-01

    A new grading system for plant-available potassium (K) in soils based on K release rate from soils and plant growth indices was established. In the study, fourteen different agricultural soils from the southern subtropical to the northern temperate zones in China were analyzed by both chemical extraction methods and exhaustive cropping techniques. Based on the change trends in plant growth indices, relative biomass yields of 70% and 50%, K-deficient coefficients of 35 and 22 under conventional exhaustive experiments, and tissue K concentrations of 40 g kg-1 and 15 g kg-1 under intensive exhaustive experiments were obtained as critical values that represent different change trends. In addition, the extraction method using 0.2 mol L-1 sodium tetraphenylboron (NaTPB) suggested soil K release rates of 12 mg kg-1 min-1 and 0.4 mg kg-1 min-1 as turning points that illustrated three different release trends. Thus, plant-available K in soils was classified into three categories: high available K, medium available K and low available K, and grading criteria and measurement methods were also proposed. This work has increased our understanding of soil K bioavailability and has direct application in terms of routine assessment of agriculture soils.

  9. Management Systems, Patient Quality Improvement, Resource Availability, and Substance Abuse Treatment Quality

    PubMed Central

    Fields, Dail; Roman, Paul M; Blum, Terry C

    2012-01-01

    Objective To examine the relationships among general management systems, patient-focused quality management/continuous process improvement (TQM/CPI) processes, resource availability, and multiple dimensions of substance use disorder (SUD) treatment. Data Sources/Study Setting Data are from a nationally representative sample of 221 SUD treatment centers through the National Treatment Center Study (NTCS). Study Design The design was a cross-sectional field study using latent variable structural equation models. The key variables are management practices, TQM/continuous quality improvement (CQI) practices, resource availability, and treatment center performance. Data Collection Interviews and questionnaires provided data from treatment center administrative directors and clinical directors in 2007–2008. Principal Findings Patient-focused TQM/CQI practices fully mediated the relationship between internal management practices and performance. The effects of TQM/CQI on performance are significantly larger for treatment centers with higher levels of staff per patient. Conclusions Internal management practices may create a setting that supports implementation of specific patient-focused practices and protocols inherent to TQM/CQI processes. However, the positive effects of internal management practices on treatment center performance occur through use of specific patient-focused TQM/CPI practices and have more impact when greater amounts of supporting resources are present. PMID:22098342

  10. Management systems, patient quality improvement, resource availability, and substance abuse treatment quality.

    PubMed

    Fields, Dail; Roman, Paul M; Blum, Terry C

    2012-06-01

    To examine the relationships among general management systems, patient-focused quality management/continuous process improvement (TQM/CPI) processes, resource availability, and multiple dimensions of substance use disorder (SUD) treatment. Data are from a nationally representative sample of 221 SUD treatment centers through the National Treatment Center Study (NTCS). The design was a cross-sectional field study using latent variable structural equation models. The key variables are management practices, TQM/continuous quality improvement (CQI) practices, resource availability, and treatment center performance. Interviews and questionnaires provided data from treatment center administrative directors and clinical directors in 2007-2008. Patient-focused TQM/CQI practices fully mediated the relationship between internal management practices and performance. The effects of TQM/CQI on performance are significantly larger for treatment centers with higher levels of staff per patient. Internal management practices may create a setting that supports implementation of specific patient-focused practices and protocols inherent to TQM/CQI processes. However, the positive effects of internal management practices on treatment center performance occur through use of specific patient-focused TQM/CPI practices and have more impact when greater amounts of supporting resources are present. © Health Research and Educational Trust.

  11. Citrulline Supplementation Improves Organ Perfusion and Arginine Availability under Conditions with Enhanced Arginase Activity.

    PubMed

    Wijnands, Karolina A P; Meesters, Dennis M; van Barneveld, Kevin W Y; Visschers, Ruben G J; Briedé, Jacob J; Vandendriessche, Benjamin; van Eijk, Hans M H; Bessems, Babs A F M; van den Hoven, Nadine; von Wintersdorff, Christian J H; Brouckaert, Peter; Bouvy, Nicole D; Lamers, Wouter H; Cauwels, Anje; Poeze, Martijn

    2015-06-29

    Enhanced arginase-induced arginine consumption is believed to play a key role in the pathogenesis of sickle cell disease-induced end organ failure. Enhancement of arginine availability with L-arginine supplementation exhibited less consistent results; however, L-citrulline, the precursor of L-arginine, may be a promising alternative. In this study, we determined the effects of L-citrulline compared to L-arginine supplementation on arginine-nitric oxide (NO) metabolism, arginine availability and microcirculation in a murine model with acutely-enhanced arginase activity. The effects were measured in six groups of mice (n = 8 each) injected intraperitoneally with sterile saline or arginase (1000 IE/mouse) with or without being separately injected with L-citrulline or L-arginine 1 h prior to assessment of the microcirculation with side stream dark-field (SDF)-imaging or in vivo NO-production with electron spin resonance (ESR) spectroscopy. Arginase injection caused a decrease in plasma and tissue arginine concentrations. L-arginine and L-citrulline supplementation both enhanced plasma and tissue arginine concentrations in arginase-injected mice. However, only the citrulline supplementation increased NO production and improved microcirculatory flow in arginase-injected mice. In conclusion, the present study provides for the first time in vivo experimental evidence that L-citrulline, and not L-arginine supplementation, improves the end organ microcirculation during conditions with acute arginase-induced arginine deficiency by increasing the NO concentration in tissues.

  12. Genetic Improvement of Switchgrass and Other Herbaceous Plants for Use as Biomass Fuel Feedstock

    SciTech Connect

    Vogel, K.P.

    2001-01-11

    It should be highly feasible to genetically modify the feedstock quality of switchgrass and other herbaceous plants using both conventional and molecular breeding techniques. Effectiveness of breeding to modify herbages of switchgrass and other perennial and annual herbaceous species has already been demonstrated. The use of molecular markers and transformation technology will greatly enhance the capability of breeders to modify the plant structure and cell walls of herbaceous plants. It will be necessary to monitor gene flow to remnant wild populations of plants and have strategies available to curtail gene flow if it becomes a potential problem. It also will be necessary to monitor plant survival and long-term productivity as affected by genetic changes that improve forage quality. Information on the conversion processes that will be used and the biomass characteristics that affect conversion efficiency and rate is absolutely essential as well as information on the relative economic value of specific traits. Because most forage or biomass quality characteristics are highly affected by plant maturity, it is suggested that plant material of specific maturity stages be used in research to determining desirable feedstock quality characteristics. Plant material could be collected at various stages of development from an array of environments and storage conditions that could be used in conversion research. The same plant material could be used to develop NIRS calibrations that could be used by breeders in their selection programs and also to develop criteria for a feedstock quality assessment program. Breeding for improved feedstock quality will likely affect the rate of improvement of biomass production per acre. If the same level of resources are used, multi-trait breeding simply reduces the selection pressure and hence the breeding progress that can be made for a single trait unless all the traits are highly correlated. Since desirable feedstock traits are likely

  13. Improving hot gas filtration behavior in PFBC power plants

    SciTech Connect

    Romeo, L.M.; Gil, A.; Cortes, C.

    1999-07-01

    According to a previous paper, a laboratory-scale cold flow model of the hot gas filtration system in Escatron PFBC power plant has been built. The main objectives were to establish the validity of the scaling laws for cyclone separator systems (cyclone and dipleg) and to perform detailed room temperature studies in a rapid and cost effective manner. In Escatron PFBC power plant, the hot gas filtration equipment is a two-stage process performed in nine streams between the fluidized bed and the gas turbine. Due to the unsteadiness in the dipleg and the suction nozzle, and the effect of sintered deposit, the cyclone performance is modified. The performances of cyclone separator system and suction nozzle diplegs are scarcely reported in the open literature. This paper presents the results of a detailed research in which some important conclusions of well known studies about cyclones are verified. Also remarkable is the increase in cyclone efficiency and decrease in pressure drop when the solid load to the cyclone is increased. The possibility to check the fouling by means of pressure drop has not been previously addressed. Finally, the influences of gas input velocity to the cyclone, the transport gas to the ash conveying lines, the solid load and the cyclone fouling have been analyzed. This study has allowed characterizing the performance of the full-scale ash removal system, establishing safe limits of operation and testing design improvements as the two suction nozzle dipleg, pointing out important conclusions for the filtration process in PFBC power plants.

  14. Effects of climate change on water demand and water availability for power plants - examples for the German capital Berlin

    NASA Astrophysics Data System (ADS)

    Voegele, Stefan; Koch, Hagen; Grünewald, Uwe

    2010-05-01

    Effects of climate change on water demand and water availability for power plants - examples for the German capital Berlin Stefan Vögelea, Hagen Kochb&c, Uwe Grünewaldb a Forschungszentrum Jülich, Institute of Energy Research - Systems Analysis and Technology Evaluation, D-52425 Jülich, Germany b Brandenburg University of Technology Cottbus, Chair Hydrology and Water Resources Management, P.O. Box. 101 344, D-03013 Cottbus, Germany c Potsdam Institute for Climate Impact Research, Research Domain Climate Impacts and Vulnerabilities, P.O. Box 601203, D-14412 Potsdam, Germany Numerous power plants in Europe had to be throttled in the summer months of the years 2003 and 2006 due to water shortages and high water temperatures. Therefore, the effects of climate change on water availability and water temperature, and their effects on electric power generation in power plants have received much attention in the last years. The water demand of a power plant for cooling depends on the temperature of the surface waters from which the cooling water is withdrawn. Furthermore, air temperature and air humidity influence the water demand if a cooling tower is used. Beside climatic parameters, the demand for water depends on economic and technological factors as well as on the electricity demand and the socio-political framework. Since the different systems are connected with certain levels of uncertainty, scenarios of socio-economic development and climate change should be used in analyses of climate change on power plants and to identify adaptation measures. In this presentation the effects of global change, comprising technological, socio-economic and climate change, and adaptation options to water shortages for power plants in the German capital Berlin in the short- and long-term are analysed. The interconnection between power plants, i.e. water demand, and water resources management, i.e. water availability, is described in detail. By changing the cooling system of power

  15. Can measures of prey availability improve our ability to predict the abundance of large marine predators?

    PubMed

    Wirsing, Aaron J; Heithaus, Michael R; Dill, Lawrence M

    2007-09-01

    Apex marine predators can structure marine communities, so factors underlying their abundance are of broad interest. However, such data are almost completely lacking for large sharks. We assessed the relationship between tiger shark abundance, water temperature, and the availability of a variety of known prey over 5 years in Western Australia. Abundance of sharks in four size categories and the density of prey (cormorants, dugongs, sea snakes, sea turtles) were indexed using daily catch rates and transects, respectively. Across all sizes, thermal conditions were a determinant of abundance, with numerical peaks coinciding with periods of high water temperature. However, for sharks exceeding 300 cm total length, the inclusion of dugong density significantly improved temperature-based models, suggesting that use of particular areas by large tiger sharks is influenced by availability of this sirenian. We conclude that large marine predator population models may benefit from the inclusion of measures of prey availability, but only if such measures consider prey types separately and account for ontogenetic shifts in the diet of the predator in question.

  16. 75 FR 29588 - Notice of Availability of the Models for Plant-Specific Adoption of Technical Specifications Task...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ..., ``Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control'' AGENCY: Nuclear Regulatory... significant hazards consideration determination) and model safety evaluation (SE) for the plant-specific... Fuel Oil and Lube Oil Volume Values to Licensee Control.'' TSTF-501, Revision 1, is available in...

  17. The role of symbiotic nitrogen fixation in nitrogen availability, competition and plant invasion into the sagebrush steppe

    Treesearch

    Erin M. Goergen

    2009-01-01

    In the semi-arid sagebrush steppe of the Northeastern Sierra Nevada, resources are both spatially and temporally variable, arguably making resource availability a primary factor determining invasion success. N fixing plant species, primarily native legumes, are often relatively abundant in sagebrush steppe and can contribute to ecosystem nitrogen budgets. ...

  18. 76 FR 19510 - Notice of Availability (NOA) of the Models For Plant-Specific Adoption of Technical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-07

    ... COMMISSION Notice of Availability (NOA) of the Models For Plant-Specific Adoption of Technical Specifications..., Revision 2. Please note, this NOA supersedes in its entirety the NOA for TSTF-422, Revision 1, published in...- specific information. The NRC will process each amendment application responding to this NOA according...

  19. Root-zone temperature and water availability affect early root growth of planted longleaf pine

    Treesearch

    M.A. Sword

    1995-01-01

    Longleaf pine seedlings from three seed sources were exposed to three root-zone temperatures and three levels of water availability for 28 days. Root growth declined as temperature and water availability decreased. Root growth differed by seed source. Results suggest that subtle changes in the regeneration environment may influence early root growth of longleaf pine...

  20. Nutrient allocation among plant organs across 13 tree species in three Bornean rain forests with contrasting nutrient availabilities.

    PubMed

    Aoyagi, Ryota; Kitayama, Kanehiro

    2016-07-01

    Allocation of nitrogen (N) and phosphorus (P) among plant organs is an important factor regulating growth rate, which is a key ecological process associated with plant life-history strategies. However, few studies have explored how N and P investment in photosynthetic (leaves) and non-photosynthetic (stems and roots) organs changes in relation to depletion of each element. We investigated nutrient concentrations of plant organs in relation to whole-plant nutrient concentration (total nutrient weight per total biomass) as an index of nutrient status of each individual using the saplings of the 13 species in three tropical rain forests with contrasting N and P availabilities (tropical evergreen forests and tropical heath forests). We found a steeper decrease in foliar N concentration than foliar P concentration with decreasing whole-plant nutrient concentration. Moreover, the steeper decrease in foliar N concentration was associated with relatively stable N concentration in stems, and vice versa for P. We suggest that the depletion of N is associated with a rapid dilution of foliar N because the cell walls in non-photosynthetic organs function as an N sink. On the other hand, these species can maintain foliar P concentration by decreasing stem P concentrations despites the depletion of P. Our results emphasize the significance of non-photosynthetic organs as an N sink for understanding the variation of foliar nutrient concentrations for the tree species in the three Bornean rain forests with different N and P availabilities.

  1. Soil respiration responses to variation in temperature and moisture availability under woody plants and grasses

    NASA Astrophysics Data System (ADS)

    Pravalprukskul, P.; Pavao-Zuckerman, M.; Barron-Gafford, G. A.

    2011-12-01

    Woody plant encroachment into grasslands, such as in the southwestern US, is thought to have altered regional carbon fluxes due to the differences in structure and function between grasses and woody plants. It is unknown how climate change predictions for such areas, particularly warmer temperatures and fewer but larger precipitation events, might further acerbate our ability to estimate flux dynamics. Soil respiration, a key flux affecting ecosystem carbon balance, has been increasingly studied, but the exact effects of temperature and precipitation changes on flux rates have not been fully determined, particularly their interactive effects. The goal of this study was to compare soil respiration responses to different temperatures in soils under native southwestern mesquites and grasses undergoing a precipitation pulse, whilst removing other confounding factors, such as soil history, through the controlled environments within Biosphere 2. Mesquites and grasses were transplanted into ground basalt within two environments maintained at a 4°C temperature difference, the projected temperature increase from climate change. Post-transplant soil samples were incubated between 10 and 40°C to determine the temperature sensitivities of soils from each microhabitat within a month of this transplant. A single-peak, best-fit model for grass soils suggested a weak temperature sensitivity, while mesquite soils showed little to no sensitivity. Additionally, all plants underwent a drought treatment prior to the precipitation event, and soil respiration rates were tracked over several days using the collar technique. This portion of the study allowed for an estimation of the sensitivity of soil respiration to precipitation pulses under a variety of antecedent moisture conditions. Initial results illustrate that soils under mesquites tend to respire significantly more than soil under grasses or in bare soils over the course of a precipitation event. Together, these results suggest

  2. EARLY ENTRANCE CO-PRODUCTION PLANT - DECENTRALIZED GASIFICATION COGENERATION TRANSPORTATION FUELS AND STEAM FROM AVAILABLE FEEDSTOCKS

    SciTech Connect

    John W. Rich

    2003-12-01

    Waste Processors Management, Inc. (WMPI), along with its subcontractors Texaco Power & Gasification (now ChevronTexaco), SASOL Technology Ltd., and Nexant Inc. entered into a Cooperative Agreement DE-FC26-00NT40693 with the U. S. Department of Energy (DOE), National Energy Technology Laboratory (NETL) to assess the techno-economic viability of building an Early Entrance Co-Production Plant (EECP) in the United States to produce ultra clean Fischer-Tropsch (FT) transportation fuels with either power or steam as the major co-product. The EECP design includes recovery and gasification of low-cost coal waste (culm) from physical coal cleaning operations and will assess blends of the culm with coal or petroleum coke. The project has three phases. Phase I is the concept definition and engineering feasibility study to identify areas of technical, environmental and financial risk. Phase II is an experimental testing program designed to validate the coal waste mixture gasification performance. Phase III updates the original EECP design based on results from Phase II, to prepare a preliminary engineering design package and financial plan for obtaining private funding to build a 5,000 barrel per day (BPD) coal gasification/liquefaction plant next to an existing co-generation plant in Gilberton, Schuylkill County, Pennsylvania. The current report covers the period performance from July 1, 2003 through September 30, 2003. The DOE/WMPI Cooperative Agreement was modified on May 2003 to expand the project team to include Shell Global Solutions, U.S. and Uhde GmbH as the engineering contractor. The addition of Shell and Uhde strengthen both the technical capability and financing ability of the project. Uhde, as the prime EPC contractor, has the responsibility to develop a LSTK (lump sum turnkey) engineering design package for the EECP leading to the eventual detailed engineering, construction and operation of the proposed concept. Major technical activities during the reporting

  3. Understanding plant responses to phosphorus starvation for improvement of plant tolerance to phosphorus deficiency by biotechnological approaches.

    PubMed

    Ha, Sukbong; Tran, Lam-Son

    2014-03-01

    In both prokaryotes and eukaryotes, including plants, phosphorus (P) is an essential nutrient that is involved in various biochemical processes, such as lipid metabolism and the biosynthesis of nucleic acids and cell membranes. P also contributes to cellular signaling cascades by function as mediators of signal transduction and it also serves as a vital energy source for a wide range of biological functions. Due to its intensive use in agriculture, P resources have become limited. Therefore, it is critically important in the future to develop scientific strategies that aim to increase P use efficiency and P recycling. In addition, the biologically available soluble form of P for uptake (phosphate; Pi) is readily washed out of topsoil layers, resulting in serious environmental pollution. In addition to this environmental concern, the wash out of Pi from topsoil necessitates a continuous Pi supply to maintain adequate levels of fertilization, making the situation worse. As a coping mechanism to P stress, plants are known to undergo drastic cellular changes in metabolism, physiology, hormonal balance and gene expression. Understanding these molecular, physiological and biochemical responses developed by plants will play a vital role in improving agronomic practices, resource conservation and environmental protection as well as serving as a foundation for the development of biotechnological strategies, which aim to improve P use efficiency in crops. In this review, we will discuss a variety of plant responses to low P conditions and various molecular mechanisms that regulate these responses. In addition, we also discuss the implication of this knowledge for the development of plant biotechnological applications.

  4. Water table and species identity outweigh carbon and nitrogen availability in a softwater plant community

    NASA Astrophysics Data System (ADS)

    Vanderhaeghe, Floris; Smolders, Alfons J. P.; Roelofs, Jan G. M.; Hoffmann, Maurice

    2013-02-01

    Performance of aquatic macrophytes is driven by many environmental factors, and a major challenge is to understand how aquatic macrophyte communities are structured in various environments. In softwater lakes in Western Europe, hydrological state (submersed/emersed), carbon dioxide and ammonium levels and species interactions are considered as driving forces in structuring amphibious plant communities. In this study we aimed at evaluating the relative importance of these factors for four species in a competitive neighbourhood. Softwater lake habitat was simulated during one growing season in laboratory conditions, mimicking water level fluctuation, photoperiod and temperature. Artificial communities consisted of small populations of four softwater macrophyte species: Luronium natans, Baldellia ranunculoides ssp. repens, Eleocharis multicaulis and Hydrocotyle vulgaris. These communities were subjected to two levels of carbon dioxide and ammonium. Additionally, monocultures of Baldellia and Eleocharis were grown at a higher nutrient level combination in order to measure their competitive response in a community. Time (hydrological state) and species identity turned out to be the only consistently significant factors determining community composition. Plant performance was clearly species-dependent, while carbon dioxide and ammonium did not have major effects. The competitive response was significant in both Eleocharis and Baldellia. Competition intensity was highest in the emersed state. Carbon dioxide had a supplementary effect on the within-species performance in Luronium, Baldellia and Eleocharis, with high carbon dioxide level mainly resulting in more flowers and more stolons. Community outcomes and competitive responses in aquatic macrophytes appear difficult to predict, because of mixed life strategies and morphological and functional plasticity. We conclude that hydrological state was the only important environmental factor. The identity of the species that

  5. Availability Improvement of Layer 2 Seamless Networks Using OpenFlow

    PubMed Central

    Molina, Elias; Jacob, Eduardo; Matias, Jon; Moreira, Naiara; Astarloa, Armando

    2015-01-01

    The network robustness and reliability are strongly influenced by the implementation of redundancy and its ability of reacting to changes. In situations where packet loss or maximum latency requirements are critical, replication of resources and information may become the optimal technique. To this end, the IEC 62439-3 Parallel Redundancy Protocol (PRP) provides seamless recovery in layer 2 networks by delegating the redundancy management to the end-nodes. In this paper, we present a combination of the Software-Defined Networking (SDN) approach and PRP topologies to establish a higher level of redundancy and thereby, through several active paths provisioned via the OpenFlow protocol, the global reliability is increased, as well as data flows are managed efficiently. Hence, the experiments with multiple failure scenarios, which have been run over the Mininet network emulator, show the improvement in the availability and responsiveness over other traditional technologies based on a single active path. PMID:25759861

  6. Availability improvement of layer 2 seamless networks using OpenFlow.

    PubMed

    Molina, Elias; Jacob, Eduardo; Matias, Jon; Moreira, Naiara; Astarloa, Armando

    2015-01-01

    The network robustness and reliability are strongly influenced by the implementation of redundancy and its ability of reacting to changes. In situations where packet loss or maximum latency requirements are critical, replication of resources and information may become the optimal technique. To this end, the IEC 62439-3 Parallel Redundancy Protocol (PRP) provides seamless recovery in layer 2 networks by delegating the redundancy management to the end-nodes. In this paper, we present a combination of the Software-Defined Networking (SDN) approach and PRP topologies to establish a higher level of redundancy and thereby, through several active paths provisioned via the OpenFlow protocol, the global reliability is increased, as well as data flows are managed efficiently. Hence, the experiments with multiple failure scenarios, which have been run over the Mininet network emulator, show the improvement in the availability and responsiveness over other traditional technologies based on a single active path.

  7. Morphological and physiological responses to sediment type and light availability in roots of the submerged plant Myriophyllum spicatum.

    PubMed

    Xie, Yonghong; Luo, Wenbo; Ren, Bo; Li, Feng

    2007-12-01

    Both sediment and light are essential factors regulating the growth of submerged macrophytes, but the role of these two factors in regulating root morphology and physiology is far from clear. The responses of root morphology and physiology to sediment type and light availability in the submerged plant Myriophyllum spicatum were studied and the hypothesis was tested that a trade-off exists in root growth strategy between internal aeration and nutrient acquisition. Plants were grown on two types of sediment (fertile mud and an infertile mixture of mud and sandy loam) and under three levels of light availability (600, 80 and 20 micro mol m(-2) s(-1)) in a greenhouse. The significantly higher alcohol dehydrogenase (ADH) activity in root tissues indicated that oxygen deficiency existed in the plants growing in fertile mud and low (or high) light environments. Significantly, low plant N and P concentrations indicated that nutrient deficiency existed in the mixed sediment and high light environment. As a response to anoxia, plants did not change the porosity of the main roots. The effect of sediment type on root morphology was insignificant under higher light environments, whereas root diameter generally decreased but specific root length (SRL) increased with decreasing light availability. Both low light and fertile mud jointly led to lack of second-order laterals. More biomass was allocated to lateral roots in infertile environments, whereas mass fractions of laterals were lower in low light and mud environments. These data indicate that this plant can achieve the trade-off between internal aeration and nutrient acquisition by adjusting the structure of the root system and the pattern of biomass allocation to different root orders rather than root morphology and root porosity.

  8. Morphological and Physiological Responses to Sediment Type and Light Availability in Roots of the Submerged Plant Myriophyllum spicatum

    PubMed Central

    Xie, Yonghong; Luo, Wenbo; Ren, Bo; Li, Feng

    2007-01-01

    Background and Aims Both sediment and light are essential factors regulating the growth of submerged macrophytes, but the role of these two factors in regulating root morphology and physiology is far from clear. The responses of root morphology and physiology to sediment type and light availability in the submerged plant Myriophyllum spicatum were studied and the hypothesis was tested that a trade-off exists in root growth strategy between internal aeration and nutrient acquisition. Method Plants were grown on two types of sediment (fertile mud and an infertile mixture of mud and sandy loam) and under three levels of light availability (600, 80 and 20 µ mol m−2 s−1) in a greenhouse. Key Results The significantly higher alcohol dehydrogenase (ADH) activity in root tissues indicated that oxygen deficiency existed in the plants growing in fertile mud and low (or high) light environments. Significantly, low plant N and P concentrations indicated that nutrient deficiency existed in the mixed sediment and high light environment. As a response to anoxia, plants did not change the porosity of the main roots. The effect of sediment type on root morphology was insignificant under higher light environments, whereas root diameter generally decreased but specific root length (SRL) increased with decreasing light availability. Both low light and fertile mud jointly led to lack of second-order laterals. More biomass was allocated to lateral roots in infertile environments, whereas mass fractions of laterals were lower in low light and mud environments. Conclusions These data indicate that this plant can achieve the trade-off between internal aeration and nutrient acquisition by adjusting the structure of the root system and the pattern of biomass allocation to different root orders rather than root morphology and root porosity. PMID:17959731

  9. 78 FR 79658 - Okanagan Specialty Fruits, Inc.; Availability of Plant Pest Risk Assessment and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ... are also available on the APHIS Web site at http://www.aphis.usda.gov/biotechnology/petitions_table..., Director, Environmental Risk Analysis Programs, Biotechnology Regulatory Services, APHIS, 4700 River Road...

  10. Stereo improves 3D shape discrimination even when rich monocular shape cues are available.

    PubMed

    Lee, Young Lim; Saunders, Jeffrey A

    2011-08-17

    We measured the ability to discriminate 3D shapes across changes in viewpoint and illumination based on rich monocular 3D information and tested whether the addition of stereo information improves shape constancy. Stimuli were images of smoothly curved, random 3D objects. Objects were presented in three viewing conditions that provided different 3D information: shading-only, stereo-only, and combined shading and stereo. Observers performed shape discrimination judgments for sequentially presented objects that differed in orientation by rotation of 0°-60° in depth. We found that rotation in depth markedly impaired discrimination performance in all viewing conditions, as evidenced by reduced sensitivity (d') and increased bias toward judging same shapes as different. We also observed a consistent benefit from stereo, both in conditions with and without change in viewpoint. Results were similar for objects with purely Lambertian reflectance and shiny objects with a large specular component. Our results demonstrate that shape perception for random 3D objects is highly viewpoint-dependent and that stereo improves shape discrimination even when rich monocular shape cues are available.

  11. Solid Lipid Nanoparticles Improve the Diclofenac Availability in Vitreous after Intraocular Injection

    PubMed Central

    Abrishami, Majid; Vakili Ahrari Roodi, Mohammad

    2016-01-01

    Purpose. In order to improve the drug availability after intravitreal administration, solid lipid nanoparticles (SLNs) containing diclofenac were prepared. Methods. In this experimental study, 18 albino rabbits were included. In right and left eyes of all rabbits, SLNs containing diclofenac and commercial form of diclofenac (0.3 mg drug) were intravitreally injected, respectively. One, four, twelve, twenty-four, and forty-eight hours after injection, vitreous and aqueous humor samples were obtained in all cases. Then, the concentration of diclofenac sodium was evaluated in all samples. Results. Size of nanoparticles was around 170 nm after preparation. Drug concentration in eyes injected with SLNs was significantly higher than left eyes injected with commercial formulation up to 4 hours after intravitreal injection (p < 0.05). Diclofenac was quantified in samples up to 48 hours after intraocular injection. Four hours after intravitreal injection, the concentration of diclofenac in vitreous and aqueous humor of eyes receiving SLNs was, respectively, 2.5 and 6.5 times higher than eyes injected with commercial form of drug. Conclusions. Here, we demonstrate the potential of SLNs as a carrier of diclofenac for intraocular injection in order to prevent the systemic effects of the drug, increase the injection intervals, and improve the patient compliance. PMID:27803815

  12. A concept for fault tolerant design and improved availability of active composite elastic structures

    NASA Astrophysics Data System (ADS)

    Soeffker, D.; Wolters, K.; Krajcin, I.

    2005-05-01

    New functionalities, higher comfort and increasing performance requirements are often be solved by adding new technologies to existing (passive) solutions. Monitoring and control approaches uses additional sensors and actuators, new materials, microprocessors and new devices realizing new and improved functionalities. Two effects are becoming more and more interesting: (1) the lifetime of new actuators/materials strongly depends on the usage-history, (2) the functionality of the new composed systems depends on the fully functionality of all elements. In the consequence, the availability of such new systems is decreased by the number of elements and depends strongly on the use. These effects are known and act against new developments improving performance behavior also in mechanical engineering, automotive systems etc. This will be also the case for multifunctional composite or compound systems such as piezomaterials, magnetostrictive alloys or smart memory alloys (SMA) and is actually within the focus of the Structural-Health-Monitoring (SHM)-community. This contribution explains a new and systematically structured methodological approach to avoid and eliminate failures in mechatronical systems in an integrated and intelligent way to achieve a desirable or required amount of utilization in compliance with a defined failure rate. The result is an enhancement of the dependability of such a system.

  13. Improvements of task performance in daily life after acquired brain injury using commonly available everyday technology.

    PubMed

    Lindén, Anita; Lexell, Jan; Larsson Lund, Maria

    2011-01-01

    To investigate how individualised occupation-based interventions with commonly available everyday technology (ET) can compensate for perceived difficulties with daily life tasks after an aquired brain injury (ABI) and improve satisfaction with occupational performance. This intervention study was designed as a multiple case study according to Yin. Ten men and women with an ABI (traumatic or non-traumatic) participated. Data were collected through interviews, observations and field notes before and after the intervention and at follow-up (on average 11 weeks afterwards). The interventions focused on enabling each participant's prioritised goals related to task performance in daily life. All participants achieved all their goals by learning to use both new functions in their own familiar ET and new ET. The participant's perceived difficulties in occupational performance decreased and their satisfaction with occupational performance increased with the use of ET. An individualised intervention process, involving the use of own familiar ET or ET off-the-shelf, has the potential to compensate for perceived difficulties following an ABI and improve satisfaction with occupational performance in daily life.

  14. Publicly Available Database : Improved Spectral Line Measurements In SDSS DR7 Galaxies

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Sarzi, M.; Schawinski, K.; Yi, S. K.

    2012-01-01

    We present a new database of absorption and emission line measurements based on the Sloan Digital Sky Survey 7th data release for the galaxies within a redshift of 0.2. Our work makes use of the publicly available penalized pixel-fitting(pPXF) and GANDALF codes, aiming to improve the existing measurements for stellar kinematics, the strength of various absorption-line features, and the flux and width of the emissions from different species of ionized gas. The absorption line strengths measured by SDSS pipeline are seriously contaminated by emission fill-in. We effectively separate emission lines from absorption lines. For instance, this work successfully extract [NI] doublet from Mgb and it leads to more realistic result of alpha enhancement on late-type galaxies compared to the previous database. Besides accurately measuring line strengths, the database provides new parameters that are indicative of line strength measurement quality. Users can build a subset of database optimal for their studies using specific cuts in the fitting quality parameters as well as empirical signal-to-noise. Applying these parameters, we found `hidden’ broad-line-region galaxies and they turned out to be Seyfert I nuclei that were not picked up as AGN by SDSS. The database is publicly available at http://gem.yonsei.ac.kr/ossy

  15. Optimizing available water capacity using microwave satellite data for improving irrigation management

    NASA Astrophysics Data System (ADS)

    Gupta, Manika; Bolten, John; Lakshmi, Venkat

    2015-04-01

    This work addresses the improvement of available water capacity by developing a technique for estimating soil hydraulic parameters through the utilization of satellite-retrieved near surface soil moisture. The prototype involves the usage of Monte Carlo analysis to assimilate historical remote sensing soil moisture data available from the Advanced Microwave Scanning Radiometer (AMSR-E) within the hydrological model. The main hypothesis used in this study is that near-surface soil moisture data contain useful information that can describe the effective hydrological conditions of the basin such that when appropriately In the method followed in this study the hydraulic parameters are derived directly from information on the soil moisture state at the AMSR-E footprint scale and the available water capacity is derived for the root zone by coupling of AMSR-E soil moisture with the physically-based hydrological model. The available capacity water, which refers to difference between the field capacity and wilting point of the soil and represent the soil moisture content at 0.33 bar and 15 bar respectively is estimated from the soil hydraulic parameters using the van Genuchten equation. The initial ranges of soil hydraulic parameters are taken in correspondence with the values available from the literature based on Soil Survey Geographic (SSURGO) database within the particular AMSR-E footprint. Using the Monte Carlo simulation, the ranges are narrowed in the region where simulation shows a good match between predicted and near-surface soil moisture from AMSR-E. In this study, the uncertainties in accurately determining the parameters of the nonlinear soil water retention function for large-scale hydrological modeling is the focus of the development of the Bayesian framework. Thus, the model forecasting has been combined with the observational information to optimize the model state and the soil hydraulic parameters simultaneously. The optimization process is divided into

  16. The availability of filament ends modulates actin stochastic dynamics in live plant cells

    PubMed Central

    Li, Jiejie; Staiger, Benjamin H.; Henty-Ridilla, Jessica L.; Abu-Abied, Mohamad; Sadot, Einat; Blanchoin, Laurent; Staiger, Christopher J.

    2014-01-01

    A network of individual filaments that undergoes incessant remodeling through a process known as stochastic dynamics comprises the cortical actin cytoskeleton in plant epidermal cells. From images at high spatial and temporal resolution, it has been inferred that the regulation of filament barbed ends plays a central role in choreographing actin organization and turnover. How this occurs at a molecular level, whether different populations of ends exist in the array, and how individual filament behavior correlates with the overall architecture of the array are unknown. Here we develop an experimental system to modulate the levels of heterodimeric capping protein (CP) and examine the consequences for actin dynamics, architecture, and cell expansion. Significantly, we find that all phenotypes are the opposite for CP-overexpression (OX) cells compared with a previously characterized cp-knockdown line. Specifically, CP OX lines have fewer filament–filament annealing events, as well as reduced filament lengths and lifetimes. Further, cp-knockdown and OX lines demonstrate the existence of a subpopulation of filament ends sensitive to CP concentration. Finally, CP levels correlate with the biological process of axial cell expansion; for example, epidermal cells from hypocotyls with reduced CP are longer than wild-type cells, whereas CP OX lines have shorter cells. On the basis of these and other genetic studies in this model system, we hypothesize that filament length and lifetime positively correlate with the extent of axial cell expansion in dark-grown hypocotyls. PMID:24523291

  17. Cyanogenic glycosides in plant-based foods available in New Zealand.

    PubMed

    Cressey, Peter; Saunders, Darren; Goodman, Janet

    2013-01-01

    Cyanogenic glycosides occur in a wide range of plant species. The potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide, which may result in acute cyanide poisoning and has also been implicated in the aetiology of several chronic diseases. One hundred retail foods were sampled and analysed for the presence of total hydrocyanic acid using an acid hydrolysis-isonicotinic/barbituric acid colourimetric method. Food samples included cassava, bamboo shoots, almonds and almond products, pome fruit products, flaxseed/linseed, stone fruit products, lima beans, and various seeds and miscellaneous products, including taro leaves, passion fruit, spinach and canned stuffed vine leaves. The concentrations of total hydrocyanic acid (the hydrocyanic acid equivalents of all cyanogenic compounds) found were consistent with or lower than concentrations reported in the scientific literature. Linseed/flaxseed contained the highest concentrations of total hydrocyanic acid of any of the analysed foods (91-178 mg kg(-1)). Linseed-containing breads were found to contain total hydrocyanic acid at concentrations expected from their linseed content, indicating little impact of processing on the total hydrocyanic acid content. Simulation modelling was used to assess the risk due to the total hydrocyanic acid in fruit juice and linseed-containing bread. 

  18. Advances in the genetic dissection of plant cell walls: tools and resources available in Miscanthus

    PubMed Central

    Slavov, Gancho; Allison, Gordon; Bosch, Maurice

    2013-01-01

    Tropical C4 grasses from the genus Miscanthus are believed to have great potential as biomass crops. However, Miscanthus species are essentially undomesticated, and genetic, molecular and bioinformatics tools are in very early stages of development. Furthermore, similar to other crops targeted as lignocellulosic feedstocks, the efficient utilization of biomass is hampered by our limited knowledge of the structural organization of the plant cell wall and the underlying genetic components that control this organization. The Institute of Biological, Environmental and Rural Sciences (IBERS) has assembled an extensive collection of germplasm for several species of Miscanthus. In addition, an integrated, multidisciplinary research programme at IBERS aims to inform accelerated breeding for biomass productivity and composition, while also generating fundamental knowledge. Here we review recent advances with respect to the genetic characterization of the cell wall in Miscanthus. First, we present a summary of recent and on-going biochemical studies, including prospects and limitations for the development of powerful phenotyping approaches. Second, we review current knowledge about genetic variation for cell wall characteristics of Miscanthus and illustrate how phenotypic data, combined with high-density arrays of single-nucleotide polymorphisms, are being used in genome-wide association studies to generate testable hypotheses and guide biological discovery. Finally, we provide an overview of the current knowledge about the molecular biology of cell wall biosynthesis in Miscanthus and closely related grasses, discuss the key conceptual and technological bottlenecks, and outline the short-term prospects for progress in this field. PMID:23847628

  19. Elevated CO2 affects plant responses to variation in boron availability

    USDA-ARS?s Scientific Manuscript database

    Effects of elevated CO2 on N relations are well studied, but effects on other nutrients, especially micronutrients, are not. We investigated effects of elevated CO2 on response to variation in boron (B) availability in three unrelated species: geranium (Pelargonium x hortorum), barley (Hordeum vulga...

  20. Effect of transgenic rhizobacteria overexpressing Citrobacter braakii appA on phytate-P availability to mung bean plants.

    PubMed

    Patel, Kuldeep J; Vig, Saurabh; Naresh Kumar, G; Archana, G

    2010-11-01

    Rhizosphere microorganisms possessing phytase activity are considered important for rendering phytate-P available to plants. In the present study, Citrobacter braakii phytase gene (appA) was over-expressed in rhizobacteria possessing plant growth promoting (PGP) traits for increasing their potential as bioinoculants. AppA was cloned under the lac promoter in the broad host-range expression vector pBBR1MCS2. Transformation of the recombinant construct pCBappA resulted in high constitutive phytase activity in all of the eight rhizobacterial strains belonging to genera Pantoea, Citrobacter, Enterobacter, Pseudomonas (two strains), Rhizobium (two strains) and Ensifer that were studied. Transgenic rhizobacterial strains were found to display varying level of phytase activity, ranging from 10 folds to 538 folds higher than the corresponding control strains. Transgenic derivative of Pseudomonas fluorescens CHA0, a well-characterized plant growth promoting rhizobacterium, showed highest expression of phytase (~8 U/ mg) activity in crude extracts. Although all transformants showed high phytase activity, rhizobacteria having ability to secrete organic acid, showed significantly higher release of P from Ca-phytate in buffered minimal media. AppA over-expressing rhizobacteria showed increased P content, dry weight (shoot) or shoot/ root ratio of mung bean (Vigna radiata) plants, to different extents, when grown in semi solid agar (SSA) medium containing Na-phytate or Ca-phytate as the P sources. This is the first report of over-expression of phytase in rhizobacterial strains and its exploitation for plant growth enhancement.

  1. Impact of Oxygen Stress and Energy Availability on Membrane Stability of Plant Cells

    PubMed Central

    RAWYLER, ANDRÉ; ARPAGAUS, SILVIO; BRAENDLE, ROLAND

    2002-01-01

    This article reviews the relationship between the energy status of plant cells under O2 stress (e.g. waterlogging) and the maintenance of membrane intactness, using information largely derived from suspension cultures of anoxia‐intolerant potato cells. Energy‐related parameters measured were fermentation end‐products (ethanol, lactate, alanine), respiratory rate, ATP, adenylate energy charge, nitrate reductase activity and biomass. ATP synthesis rates were calculated from the first four parameters. Reactive oxygen species were estimated from H2O2 and superoxide levels, and the enzymatic detoxification potential from the activity levels of catalase and superoxide dismutase. Structure‐related parameters were total fatty acids, free fatty acids (FFAs), lipid hydroperoxides, total phospholipids, N‐acylphosphatidylethanolamine (NAPE) and cell viability. The following issues are addressed in this review: (1) what is the impact of anoxia on membrane lipids and how does this relate to energy status; (2) does O2 per se play a role in these changes; (3) under which conditions and to what extent does lipid peroxidation occur upon re‐aeration; and (4) can the effects of re‐aeration be distinguished from those of anoxia? The emerging picture is a reappraisal of the relative contributions of anoxia and re‐aeration. Two successive phases (pre‐lytic and lytic) characterize potato cells under anoxia. They are connected by a threshold in ATP production rate, below which membrane lipids are hydrolysed to FFAs, and NAPE increases. Since lipid peroxidation occurs only when cells are reoxygenated during the lytic phase, its biological relevance in an already damaged system is questionable. PMID:12324274

  2. Impact of oxygen stress and energy availability on membrane stability of plant cells.

    PubMed

    Rawyler, André; Arpagaus, Silvio; Braendle, Roland

    2002-10-01

    This article reviews the relationship between the energy status of plant cells under O(2) stress (e.g. waterlogging) and the maintenance of membrane intactness, using information largely derived from suspension cultures of anoxia-intolerant potato cells. Energy-related parameters measured were fermentation end-products (ethanol, lactate, alanine), respiratory rate, ATP, adenylate energy charge, nitrate reductase activity and biomass. ATP synthesis rates were calculated from the first four parameters. Reactive oxygen species were estimated from H(2)O(2) and superoxide levels, and the enzymatic detoxification potential from the activity levels of catalase and superoxide dismutase. Structure-related parameters were total fatty acids, free fatty acids (FFAs), lipid hydroperoxides, total phospholipids, N-acylphosphatidylethanolamine (NAPE) and cell viability. The following issues are addressed in this review: (1) what is the impact of anoxia on membrane lipids and how does this relate to energy status; (2) does O(2) per se play a role in these changes; (3) under which conditions and to what extent does lipid peroxidation occur upon re-aeration; and (4) can the effects of re-aeration be distinguished from those of anoxia? The emerging picture is a reappraisal of the relative contributions of anoxia and re-aeration. Two successive phases (pre-lytic and lytic) characterize potato cells under anoxia. They are connected by a threshold in ATP production rate, below which membrane lipids are hydrolysed to FFAs, and NAPE increases. Since lipid peroxidation occurs only when cells are reoxygenated during the lytic phase, its biological relevance in an already damaged system is questionable.

  3. DUV light source availability improvement via further enhancement of gas management technologies

    NASA Astrophysics Data System (ADS)

    Riggs, Daniel J.; O'Brien, Kevin; Brown, Daniel J. W.

    2011-04-01

    The continuous evolution of the semiconductor market necessitates ever-increasing improvements in DUV light source uptime as defined in the SEMI E10 standard. Cymer is developing technologies to exceed current and projected light source availability requirements via significant reduction in light source downtime. As an example, consider discharge chamber gas management functions which comprise a sizable portion of DUV light source downtime. Cymer's recent introduction of Gas Lifetime Extension (GLXTM) as a productivity improvement technology for its DUV lithography light sources has demonstrated noteworthy reduction in downtime. This has been achieved by reducing the frequency of full gas replenishment events from once per 100 million pulses to as low as once per 2 billion pulses. Cymer has continued to develop relevant technologies that target further reduction in downtime associated with light source gas management functions. Cymer's current subject is the development of technologies to reduce downtime associated with gas state optimization (e.g. total chamber gas pressure) and gas life duration. Current gas state optimization involves execution of a manual procedure at regular intervals throughout the lifetime of light source core components. Cymer aims to introduce a product enhancement - iGLXTM - that eliminates the need for the manual procedure and, further, achieves 4 billion pulse gas lives. Projections of uptime on DUV light sources indicate that downtime associated with gas management will be reduced by 70% when compared with GLX2. In addition to reducing downtime, iGLX reduces DUV light source cost of operation by constraining gas usage. Usage of fluorine rich Halogen gas mix has been reduced by 20% over GLX2.

  4. Effects of clonal integration on the invasive clonal plant Alternanthera philoxeroides under heterogeneous and homogeneous water availability

    PubMed Central

    You, Wen-Hua; Han, Cui-Min; Liu, Chun-Hua; Yu, Dan

    2016-01-01

    Many notorious invasive plants are clonal, living in heterogeneous or homogeneous habitats. To understand how clonal integration affects the performance of these plants in different habitat conditions, an 8-week greenhouse experiment was conducted: ramet pairs of A. philoxeroides were grown in two habitats, either heterogeneous or homogeneous in water availability, with the stolon connections either severed or kept intact. Under heterogeneous water availability, compared with ramets in homogeneous habitats, clonal integration significantly promoted the growth and photosynthetic performance of water-stressed apical ramets, whereas it only increased the photosynthetic performance but did not affect the growth of water-stressed basal ramets. Moreover, clonal integration markedly increased the root/shoot ratios of ramets grown in habitats with high water supply but decreased it under low water availability. Under homogeneous water availability, stolon connection (clonal integration) did not influence the growth, photosynthetic performance and biomass allocation of water-stressed ramets, but it significantly promoted the growth of well-watered ramets in both apical and basal sections. These findings deepen our understanding of the bidirectional and differentiated (mainly acropetal) clonal integration of A. philoxeroides, suggesting that the invasive plant A. philoxeroides can benefit from clonal integration in both heterogeneous and homogeneous habitats. PMID:27416868

  5. Ethylene resistance in flowering ornamental plantsimprovements and future perspectives

    PubMed Central

    Olsen, Andreas; Lütken, Henrik; Hegelund, Josefine Nymark; Müller, Renate

    2015-01-01

    Various strategies of plant breeding have been attempted in order to improve the ethylene resistance of flowering ornamental plants. These approaches span from conventional techniques such as simple cross-pollination to new breeding techniques which modify the plants genetically such as precise genome-editing. The main strategies target the ethylene pathway directly; others focus on changing the ethylene pathway indirectly via pathways that are known to be antagonistic to the ethylene pathway, e.g. increasing cytokinin levels. Many of the known elements of the ethylene pathway have been addressed experimentally with the aim of modulating the overall response of the plant to ethylene. Elements of the ethylene pathway that appear particularly promising in this respect include ethylene receptors as ETR1, and transcription factors such as EIN3. Both direct and indirect approaches seem to be successful, nevertheless, although genetic transformation using recombinant DNA has the ability to save much time in the breeding process, they are not readily used by breeders yet. This is primarily due to legislative issues, economic issues, difficulties of implementing this technology in some ornamental plants, as well as how these techniques are publically perceived, particularly in Europe. Recently, newer and more precise genome-editing techniques have become available and they are already being implemented in some crops. New breeding techniques may help change the current situation and pave the way toward a legal and public acceptance if products of these technologies are indistinguishable from plants obtained by conventional techniques. PMID:26504580

  6. Expression of peanut Iron Regulated Transporter 1 in tobacco and rice plants confers improved iron nutrition.

    PubMed

    Xiong, Hongchun; Guo, Xiaotong; Kobayashi, Takanori; Kakei, Yusuke; Nakanishi, Hiromi; Nozoye, Tomoko; Zhang, Lixia; Shen, Hongyun; Qiu, Wei; Nishizawa, Naoko K; Zuo, Yuanmei

    2014-07-01

    Iron (Fe) limitation is a widespread agricultural problem in calcareous soils and severely limits crop production. Iron Regulated Transporter 1 (IRT1) is a key component for Fe uptake from the soil in dicot plants. In this study, the peanut (Arachis hypogaea L.) AhIRT1 was introduced into tobacco and rice plants using an Fe-deficiency-inducible artificial promoter. Induced expression of AhIRT1 in tobacco plants resulted in accumulation of Fe in young leaves under Fe deficient conditions. Even under Fe-excess conditions, the Fe concentration was also markedly enhanced, suggesting that the Fe status did not affect the uptake and translocation of Fe by AhIRT1 in the transgenic plants. Most importantly, the transgenic tobacco plants showed improved tolerance to Fe limitation in culture in two types of calcareous soils. Additionally, the induced expression of AhIRT1 in rice plants also resulted in high tolerance to low Fe availability in calcareous soils.

  7. A review on plants used for improvement of sexual performance and virility.

    PubMed

    Chauhan, Nagendra Singh; Sharma, Vikas; Dixit, V K; Thakur, Mayank

    2014-01-01

    The use of plant or plant-based products to stimulate sexual desire and to enhance performance and enjoyment is almost as old as the human race itself. The present paper reviews the active, natural principles, and crude extracts of plants, which have been useful in sexual disorders, have potential for improving sexual behaviour and performance, and are helpful in spermatogenesis and reproduction. Review of refereed journals and scientific literature available in electronic databases and traditional literature available in India was extensively performed. The work reviews correlation of the evidence with traditional claims, elucidation, and evaluation of a plausible concept governing the usage of plants as aphrodisiac in total. Phytoconstituents with known structures have been classified in appropriate chemical groups and the active crude extracts have been tabulated. Data on their pharmacological activity, mechanism of action, and toxicity are reported. The present review provides an overview of the herbs and their active molecule with claims for improvement of sexual behaviour. A number of herbal drugs have been validated for their effect on sexual behavior and fertility and can therefore serve as basis for the identification of new chemical leads useful in sexual and erectile dysfunction.

  8. A Review on Plants Used for Improvement of Sexual Performance and Virility

    PubMed Central

    Chauhan, Nagendra Singh; Sharma, Vikas; Dixit, V. K.; Thakur, Mayank

    2014-01-01

    The use of plant or plant-based products to stimulate sexual desire and to enhance performance and enjoyment is almost as old as the human race itself. The present paper reviews the active, natural principles, and crude extracts of plants, which have been useful in sexual disorders, have potential for improving sexual behaviour and performance, and are helpful in spermatogenesis and reproduction. Review of refereed journals and scientific literature available in electronic databases and traditional literature available in India was extensively performed. The work reviews correlation of the evidence with traditional claims, elucidation, and evaluation of a plausible concept governing the usage of plants as aphrodisiac in total. Phytoconstituents with known structures have been classified in appropriate chemical groups and the active crude extracts have been tabulated. Data on their pharmacological activity, mechanism of action, and toxicity are reported. The present review provides an overview of the herbs and their active molecule with claims for improvement of sexual behaviour. A number of herbal drugs have been validated for their effect on sexual behavior and fertility and can therefore serve as basis for the identification of new chemical leads useful in sexual and erectile dysfunction. PMID:25215296

  9. Drivers of Plant-Availability of Phosphorus from Thermally Conditioned Sewage Sludge as Assessed by Isotopic Labeling

    PubMed Central

    Andriamananjara, Andry; Rabeharisoa, Lilia; Prud’homme, Loïc; Morel, Christian

    2016-01-01

    Urban sewage sludge is a potential source of phosphorus (P) for agriculture and represents an alternative way to recycle P as fertilizer. However, the use of thermally conditioned sewage sludge (TCSS) required an accurate assessment of its value as P-fertilizer. This work aimed at assessing the plant-availability of P from TCSS. Uptake of P by a mixture of ryegrass and fescue from TCSS and triple super phosphate (TSP) fertilizers was studied using 32P-labeling technique in a greenhouse experiment. Phosphorus was applied at the rate of 50 mg P kg−1.We also conducted incubation experiments considering the same treatments to assess soil microbial respiration. Applications of TCSS and TSP increased plant P uptake that is related to the root P acquisition. The P taken up by plant from soil plant-available P was lower for control compared to TSP or TCSS that was attributed to the increase of root interception of soil P. The contribution of TSP to ryegrass nutrition (Pdff%) was 55% with 22% of the applied P which was taken up by plants (CPU%). The Pdff value for TCSS was 56% with 14% of fertilizer P recovery (CPU%). Shoot biomass and total P uptake from TCSS were lower than those from TSP. As a result, the agronomic effectiveness of TCSS calculated from Pdff value (in comparison with TSP treatment) was 102%, while the AE of TCSS estimated from CPU value (in % TSP) was 64%, which is attributed to microbial activity stimulation inducing P immobilization onto soil constituents and microbial biomass during plant growth. The high C/N ratio of TCSS stimulated soil microbial biomass that competes with plant roots to acquire nutrients, such as P. As a consequence, the P taken up from either native soil or TCSS decreased in similar proportions. The AE value calculated with Pdff% took into account these interactions between soil, plant, and microbial biomass, and is less dependent on operational conditions than the AE value calculated with %Precovery. PMID:27379240

  10. Drivers of Plant-Availability of Phosphorus from Thermally Conditioned Sewage Sludge as Assessed by Isotopic Labeling.

    PubMed

    Andriamananjara, Andry; Rabeharisoa, Lilia; Prud'homme, Loïc; Morel, Christian

    2016-01-01

    Urban sewage sludge is a potential source of phosphorus (P) for agriculture and represents an alternative way to recycle P as fertilizer. However, the use of thermally conditioned sewage sludge (TCSS) required an accurate assessment of its value as P-fertilizer. This work aimed at assessing the plant-availability of P from TCSS. Uptake of P by a mixture of ryegrass and fescue from TCSS and triple super phosphate (TSP) fertilizers was studied using (32)P-labeling technique in a greenhouse experiment. Phosphorus was applied at the rate of 50 mg P kg(-1).We also conducted incubation experiments considering the same treatments to assess soil microbial respiration. Applications of TCSS and TSP increased plant P uptake that is related to the root P acquisition. The P taken up by plant from soil plant-available P was lower for control compared to TSP or TCSS that was attributed to the increase of root interception of soil P. The contribution of TSP to ryegrass nutrition (Pdff%) was 55% with 22% of the applied P which was taken up by plants (CPU%). The Pdff value for TCSS was 56% with 14% of fertilizer P recovery (CPU%). Shoot biomass and total P uptake from TCSS were lower than those from TSP. As a result, the agronomic effectiveness of TCSS calculated from Pdff value (in comparison with TSP treatment) was 102%, while the AE of TCSS estimated from CPU value (in % TSP) was 64%, which is attributed to microbial activity stimulation inducing P immobilization onto soil constituents and microbial biomass during plant growth. The high C/N ratio of TCSS stimulated soil microbial biomass that competes with plant roots to acquire nutrients, such as P. As a consequence, the P taken up from either native soil or TCSS decreased in similar proportions. The AE value calculated with Pdff% took into account these interactions between soil, plant, and microbial biomass, and is less dependent on operational conditions than the AE value calculated with %Precovery.

  11. Supplemental Blue LED Lighting Array to Improve the Signal Quality in Hyperspectral Imaging of Plants

    PubMed Central

    Mahlein, Anne-Katrin; Hammersley, Simon; Oerke, Erich-Christian; Dehne, Heinz-Wilhelm; Goldbach, Heiner; Grieve, Bruce

    2015-01-01

    Hyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400–500 nm) of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs) with an emission peak at 470 nm. PMID:26039423

  12. Supplemental blue LED lighting array to improve the signal quality in hyperspectral imaging of plants.

    PubMed

    Mahlein, Anne-Katrin; Hammersley, Simon; Oerke, Erich-Christian; Dehne, Heinz-Wilhelm; Goldbach, Heiner; Grieve, Bruce

    2015-06-01

    Hyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400-500 nm) of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs) with an emission peak at 470 nm.

  13. The most commonly available woody plant species are the most useful for human populations: a meta-analysis.

    PubMed

    Gonçalves, Paulo Henrique Santos; Albuquerque, Ulysses Paulino; Medeiros, Patrícia Muniz de

    2016-10-01

    An increasing number of studies have aimed to clarify the factors leading human groups to prioritize the use of some woody plant species compared to others. Some of these studies have tested the apparency hypothesis in aiming to understand this phenomenon. According to the apparency hypothesis, the most commonly available local plant species on a forest path are the most useful to that local human population. However, the sparse and diverse nature of the results from studies investigating the factors that influence human exploitation of plant resources motivated us to perform a meta-analysis on the apparency hypothesis. We searched in the main databases (Scopus, ScienceDirect, Google Scholar, and Scielo) for studies that correlated the environmental availability of woody species (estimated through vegetation parameters) with the degree of importance of such species to the local human population (estimated by means of the use value index). Overall, this meta-analysis supported the apparency hypothesis, although we also found high levels of heterogeneity in these studies. When the distinct uses of woody flora were considered separately, we found that local species availability is important for fuelwood (firewood and charcoal) and construction (houses, fences, etc.) purposes but does not explain medicinal and technological (object manufacture) plant use. We found no important differences in correlation values between the degree of species importance for people and the different vegetation parameters, although correlations are slightly higher for the dominance and importance value index. Our findings suggest that the exploitation of woody flora is influenced by local availability.

  14. How Plant Hydraulics can Improve the Modeling of Plant and Ecosystem Responses to Environment

    NASA Astrophysics Data System (ADS)

    Sperry, J.; Anderegg, W.; Mackay, D. S.; Venturas, M.

    2016-12-01

    Stomatal regulation is an important, yet problematic component in modeling plant-environment interactions. The problem is that stomata respond to so many environmental cues via complex and uncertain mechanisms. But the assumed end result of regulation is conceptually simple: an optimization of CO2 for H2O exchange in response to changing conditions. Stomata open when photosynthetic opportunity is high and water is cheap. They close if photosynthetic opportunity is low or water is very expensive. Photosynthetic opportunity is relatively easy to model. The cost of water loss is also easy to model if it is assumed to rise with greater proximity to hydraulic failure and desiccation. Unsaturated hydraulic conductivity curves of soil- and plant are used to estimate proximity to failure. At any given instant, a model can calculate opportunity and cost curves associated with greater stomatal opening. If stomata regulate to maximize the instantaneous difference between photosynthetic gain and hydraulic cost, then a model can predict the trajectory of stomatal responses to changes in environment across time. Results of this optimization routine extend the utility of hydraulic predecessor models, and are consistent with widely used empirical models across a wide range of vapor pressure deficit and ambient CO2 concentrations for wet soil. The advantage of the optimization approach is the absence of empirical coefficients, applicability to dry as well as wet soil, and prediction of plant hydraulic status along with gas exchange. The optimization algorithm is a trait- and process-based approach that could improve next generation land surface models.

  15. Projected techno-economic improvements for advanced solar thermal power plants

    NASA Technical Reports Server (NTRS)

    Fujita, T.; Manvi, R.; Roschke, E. J.

    1979-01-01

    The projected characteristics of solar thermal power plants (with outputs up to 10 MWe) employing promising advanced technology subsystems/components are compared to current (or pre-1985) steam-Rankine systems. Improvements accruing to advanced technology development options are delineated. The improvements derived from advanced systems result primarily from achieving high efficiencies via solar collector systems which (1) capture a large portion of the available insolation and (2) concentrate this captured solar flux to attain high temperatures required for high heat engine/energy conversion performance. The most efficient solar collector systems employ two-axis tracking. Attractive systems include the central receiver/heliostat and the parabolic dish.

  16. Projected techno-economic improvements for advanced solar thermal power plants

    NASA Technical Reports Server (NTRS)

    Fujita, T.; Manvi, R.; Roschke, E. J.

    1979-01-01

    The projected characteristics of solar thermal power plants (with outputs up to 10 MWe) employing promising advanced technology subsystems/components are compared to current (or pre-1985) steam-Rankine systems. Improvements accruing to advanced technology development options are delineated. The improvements derived from advanced systems result primarily from achieving high efficiencies via solar collector systems which (1) capture a large portion of the available insolation and (2) concentrate this captured solar flux to attain high temperatures required for high heat engine/energy conversion performance. The most efficient solar collector systems employ two-axis tracking. Attractive systems include the central receiver/heliostat and the parabolic dish.

  17. Manipulation of Carotenoid Content in Plants to Improve Human Health.

    PubMed

    Alós, Enriqueta; Rodrigo, Maria Jesús; Zacarias, Lorenzo

    2016-01-01

    Carotenoids are essential components for human nutrition and health, mainly due to their antioxidant and pro-vitamin A activity. Foods with enhanced carotenoid content and composition are essential to ensure carotenoid feasibility in malnourished population of many countries around the world, which is critical to alleviate vitamin A deficiency and other health-related disorders. The pathway of carotenoid biosynthesis is currently well understood, key steps of the pathways in different plant species have been characterized and the corresponding genes identified, as well as other regulatory elements. This enables the manipulation and improvement of carotenoid content and composition in order to control the nutritional value of a number of agronomical important staple crops. Biotechnological and genetic engineering-based strategies to manipulate carotenoid metabolism have been successfully implemented in many crops, with Golden rice as the most relevant example of β-carotene improvement in one of the more widely consumed foods. Conventional breeding strategies have been also adopted in the bio-fortification of carotenoid in staple foods that are highly consumed in developing countries, including maize, cassava and sweet potatoes, to alleviate nutrition-related problems. The objective of the chapter is to summarize major breakthroughs and advances in the enhancement of carotenoid content and composition in agronomical and nutritional important crops, with special emphasis to their potential impact and benefits in human nutrition and health.

  18. Planting the [open quote]seeds[close quote] for increased water availability for hydro

    SciTech Connect

    Griffith, D.A. )

    1993-08-01

    Cloud seeding programs are providing some hydro producers with a way of increasing their water reserves on short notice and with relatively low cost. The fundamental formula has been known for half a century: clouds plus cold plus solid particles equal precipitation. What was not certain until more recently is how that relationship could be effectively used to alter the weather in positive ways. Research and practical experience now show that cloud seeding -- adding tiny solid particles to the right clouds at the right temperature -- works. More pertinent, evidence is mounting that hydropower producers can use well-designed, carefully times seeding programs to increase the amount of water available to their systems and thus enhance electricity generation. Cloud seeding has several advantages as a tool to augment hydroelectric production. Seeding programs typically require no capital investment by the utility or other power producer, and can be started and stopped on relatively short notice. Operating costs usually are less than $10 per acre-foot of additional streamflow. More broadly, the additional water produced for hydro generation has the environmental and community relations benefits of being reusable and less expensive than thermal power alternatives. There also normally are the additional benefits of increased water supplies for other users.

  19. Plant available silicon in South-east Asian rice paddy soils - relevance of agricultural practice and of abiotic factors

    NASA Astrophysics Data System (ADS)

    Marxen, A.; Klotzbücher, T.; Vetterlein, D.; Jahn, R.

    2012-12-01

    Background Silicon (Si) plays a crucial role in rice production. Si content of rice plants exceeds the content of other major nutrients such as nitrogen, phosphorous or potassium. Recent studies showed that in some environments external supply of Si can enhance the growth of rice plants. Rice plants express specific Si transporters to absorb Si from soil solutions in form of silicic acid, which precipitates in tissue cells forming amorphous silica bodies, called phytoliths. The phytoliths are returned to soils with plant residues. They might be a main source of plant available silicic acid in soils. Aims In this study we assess the effects of rice paddy cultivation on the stocks of `reactive` Si fractions in mineral topsoils of rice paddy fields in contrasting landscapes. The `reactive` Si fractions are presumed to determine the release of plant-available silicic acid in soils. We consider the relevance of abiotic factors (mineral assemblage; soil weathering status) and agricultural practice for these fractions. Agricultural practices, which were assumed to affect the stocks of `reactive` Si were (i) the usage of different rice varieties (which might differ in Si demand), (ii) straw residue management (i.e., whether straw residues are returned to the fields or removed and used e.g. as fodder), and (iii) yield level and number of crops per year. Material and methods Soils (top horizon of about 0-20 cm depth) were sampled from rice paddy fields in 2 mountainous and 5 lowland landscapes of contrasting geologic conditions in Vietnam and the Philippines. Ten paddy fields were sampled per landscape. The rice paddy management within landscapes differed when different farmers and/or communities managed the fields. We analysed the following fractions of `reactive` Si in the soils: acetate-extractable Si (dissolved and easily exchangeable Si), phosphate-extractable Si (adsorbed Si), oxalate extractable Si (Si associated with poorly-ordered sesquioxides), NaOH extractable Si

  20. Manipulating microRNAs for improved biomass and biofuels from plant feedstocks.

    PubMed

    Trumbo, Jennifer Lynn; Zhang, Baohong; Stewart, Charles Neal

    2015-04-01

    Petroleum-based fuels are nonrenewable and unsustainable. Renewable sources of energy, such as lignocellulosic biofuels and plant metabolite-based drop-in fuels, can offset fossil fuel use and reverse environmental degradation through carbon sequestration. Despite these benefits, the lignocellulosic biofuels industry still faces many challenges, including the availability of economically viable crop plants. Cell wall recalcitrance is a major economic barrier for lignocellulosic biofuels production from biomass crops. Sustainability and biomass yield are two additional, yet interrelated, foci for biomass crop improvement. Many scientists are searching for solutions to these problems within biomass crop genomes. MicroRNAs (miRNAs) are involved in almost all biological and metabolic process in plants including plant development, cell wall biosynthesis and plant stress responses. Because of the broad functions of their targets (e.g. auxin response factors), the alteration of plant miRNA expression often results in pleiotropic effects. A specific miRNA usually regulates a biologically relevant bioenergy trait. For example, relatively low miR156 overexpression leads to a transgenic feedstock with enhanced biomass and decreased recalcitrance. miRNAs have been overexpressed in dedicated bioenergy feedstocks such as poplar and switchgrass yielding promising results for lignin reduction, increased plant biomass, the timing of flowering and response to harsh environments. In this review, we present the status of miRNA-related research in several major biofuel crops and relevant model plants. We critically assess published research and suggest next steps for miRNA manipulation in feedstocks for increased biomass and sustainability for biofuels and bioproducts.

  1. ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE (CT)/COMBINED CYCLE (CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

    SciTech Connect

    Leonard Angello

    2002-04-01

    Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. Such systems would interpret sensor and instrument outputs, correlate them to the machine's condition, provide interpretative analyses, forward projections of servicing intervals, estimate remaining component life, and identify faults. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, it will enable real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and

  2. Improved Automated Detection of Diabetic Retinopathy on a Publicly Available Dataset Through Integration of Deep Learning.

    PubMed

    Abràmoff, Michael David; Lou, Yiyue; Erginay, Ali; Clarida, Warren; Amelon, Ryan; Folk, James C; Niemeijer, Meindert

    2016-10-01

    To compare performance of a deep-learning enhanced algorithm for automated detection of diabetic retinopathy (DR), to the previously published performance of that algorithm, the Iowa Detection Program (IDP)-without deep learning components-on the same publicly available set of fundus images and previously reported consensus reference standard set, by three US Board certified retinal specialists. We used the previously reported consensus reference standard of referable DR (rDR), defined as International Clinical Classification of Diabetic Retinopathy moderate, severe nonproliferative (NPDR), proliferative DR, and/or macular edema (ME). Neither Messidor-2 images, nor the three retinal specialists setting the Messidor-2 reference standard were used for training IDx-DR version X2.1. Sensitivity, specificity, negative predictive value, area under the curve (AUC), and their confidence intervals (CIs) were calculated. Sensitivity was 96.8% (95% CI: 93.3%-98.8%), specificity was 87.0% (95% CI: 84.2%-89.4%), with 6/874 false negatives, resulting in a negative predictive value of 99.0% (95% CI: 97.8%-99.6%). No cases of severe NPDR, PDR, or ME were missed. The AUC was 0.980 (95% CI: 0.968-0.992). Sensitivity was not statistically different from published IDP sensitivity, which had a CI of 94.4% to 99.3%, but specificity was significantly better than the published IDP specificity CI of 55.7% to 63.0%. A deep-learning enhanced algorithm for the automated detection of DR, achieves significantly better performance than a previously reported, otherwise essentially identical, algorithm that does not employ deep learning. Deep learning enhanced algorithms have the potential to improve the efficiency of DR screening, and thereby to prevent visual loss and blindness from this devastating disease.

  3. Assessing biochar and compost from the organic fraction of municipal solid waste on nutrient availability and plant growth of lettuce

    NASA Astrophysics Data System (ADS)

    Regkouzas, Panagiotis; Manolikaki, Ioanna; Diamadopoulos, Evan

    2017-04-01

    Biochars have a high variability in chemical composition, which is determined by types of feedstock and pyrolysis conditions. Inorganic compounds, such as N, P, K and Ca, retained in biochar could be released and become available to plants. The aim of this study was to understand the effect of biochar and compost addition, derived from the organic fraction of municipal solid wastes at two different pyrolysis temperatures 3000C (BC300) and 6000C (BC600), on phosphorus availability and plant growth of lettuce (Lactuca sativa L.) grown in an alkaline loam soil. This type of soil is widely available in Greece, leading us to investigate ways to increase its fertility. A 39 d growth period of lettuce was studied in a greenhouse in triplicate. Treatments comprised of control soils (no addition of biochar or compost), soils treated only with compost (5%) or biochar (5%), and combinations of biochar (5%) plus compost (5%). No fertilization was added to any of the treatments. One biomass cut was obtained. Plant shoot yield and height were determined along with elemental concentration (N, P, K, Ca, Mg, Mn, Fe, Zn, Cu) and uptake of shoots. Results showed that BC300 combined with compost significantly increased P uptake of lettuce. On the other hand, BC600 plus compost, along with the two biochar-only treatments, significantly decreased Ca and Mg uptake of lettuce. N, K, Fe, Zn, Mn and Cu uptakes were not affected by the application of biochar, compost or the combined treatments. Despite the significant increase of P uptake, plant height and shoot yield were not significantly influenced by any of the treatments.

  4. Improvement of plant growth and nickel uptake by nickel resistant-plant-growth promoting bacteria.

    PubMed

    Ma, Ying; Rajkumar, Mani; Freitas, Helena

    2009-07-30

    In this study, among a collection of Ni-resistant bacterial strains isolated from the rhizosphere of Alyssum serpyllifolium and Phleum phleoides grown on serpentine soil, five plant growth-promoting bacteria (PGPB) were selected based on their ability to utilize 1-aminocyclopropane-1-carboxylate (ACC) as the sole N source and promote seedling growth. All of the strains tested positive for indole-3-acetic acid (IAA) production and phosphate solubilization. In addition, four of the strains exhibited significant levels of siderophores production. Further, the efficiency of PGPB in enhancing Ni solubilization in soils was analyzed. Compared with control treatment, inoculation of PGPB strains significantly increased the concentrations of bioavailable Ni. Furthermore, a pot experiment was conducted to elucidate the effects of inoculating Ni-resistant PGPB on the plant growth and the uptake of Ni by Brassica juncea and B. oxyrrhina in soil contaminated with 450 mg kg(-1) Ni. Psychrobacter sp. SRA2 significantly increased the fresh (351%) and dry biomass (285%) of the B. juncea test plants (p<0.05), whereas Psychrobacter sp. SRA1 and Bacillus cereus SRA10 significantly increased the accumulation of Ni in the root and shoot tissues of B. juncea compared with non-inoculated controls. This result indicates that the strains SRA1 and SRA10 facilitated the release of Ni from the non-soluble phases in the soil, thus enhancing the availability of Ni to plants. A significant increase, greater than that of the control, was also noted for growth parameters of the B. oxyrrhina test plants when the seeds were treated with strain SRA2. This effect can be attributed to the utilization of ACC, solubilization of phosphate and production of IAA. The results of the study revealed that the inoculation of Ni mobilizing strains Psychrobacter sp. SRA1 and B. cereus SRA10 increases the efficiency of phytoextraction directly by enhancing the metal accumulation in plant tissues and the efficient

  5. Mobility and plant availability of risk elements in soil after long-term application of farmyard manure.

    PubMed

    Tlustoš, Pavel; Hejcman, Michal; Hůlka, Martin; Patáková, Michaela; Kunzová, Eva; Száková, Jiřina

    2016-12-01

    Crop rotation long-term field experiments were established in 1955 and 1956 at three locations in the Czech Republic (Čáslav, Ivanovice, and Lukavec) differing in their climatic and soil physicochemical properties. The effect of long-term application of farmyard manure and farmyard manure + NPK treatments on plant-available, easily mobilizable, potentially mobilizable, and pseudo-total contents of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) contents in soils (in 2013) as well as the uptake of these elements by winter wheat (Triticum aestivum L.) grain and straw were analyzed in the two following seasons: 2012 and 2013. The treatments resulted in increasing the soil pH level when compared to the control, but the cation exchange capacity remained unchanged. Although all fertilizers were applied for six decades, the pseudo-total concentration elements in both the soil and wheat plants stayed far below those of the Czech and European threshold limits for agricultural soils and cereals for human nutrition and feedstuff. Although the mobile pools of As, Cu, and Zn were slightly changed at the treated soils, these changes were not related to the element uptake by the wheat plants. Moreover, the effect of the location and growing season was more decisive for the differences in soil and plant element contents than for the individual treatments. Thus, the long-term application of farmyard manure did not result in any substantial change in risk element contents in both soils and winter wheat plants.

  6. Plant availability of nutrients recovered as solids from human urine tested in climate chamber on Triticum aestivum L.

    PubMed

    Ganrot, Zsófia; Dave, Göran; Nilsson, Eva; Li, Bo

    2007-11-01

    Recovered nutrients by freezing-thawing from human urine in combination with struvite precipitation and nitrogen adsorption on zeolite and activated carbon have been tested in pot trials with wheat, Triticum aestivum L., in a climate chamber during 21 days. A simple test design using sand as substrate was chosen to give a first, general evaluation of the nutrient (P and N) availability from these sources. Dry weight, plant growth morphology, total-P and total-N were analysed. The tests show a slow-release of nutrients (P and N) from struvite and from N-adsorbents. The nitrogen in all treatments was in the deficiency range for optimum yield for wheat. Higher pH than usual for soil tests contributed to the difficulties in plant uptake, especially in the pots with only struvite (with highest MgO addition) as nutrient source.

  7. Temporal changes in the structure of a plant-frugivore network are influenced by bird migration and fruit availability.

    PubMed

    Ramos-Robles, Michelle; Andresen, Ellen; Díaz-Castelazo, Cecilia

    2016-01-01

    Background. Ecological communities are dynamic collections whose composition and structure change over time, making up complex interspecific interaction networks. Mutualistic plant-animal networks can be approached through complex network analysis; these networks are characterized by a nested structure consisting of a core of generalist species, which endows the network with stability and robustness against disturbance. Those mutualistic network structures can vary as a consequence of seasonal fluctuations and food availability, as well as the arrival of new species into the system that might disorder the mutualistic network structure (e.g., a decrease in nested pattern). However, there is no assessment on how the arrival of migratory species into seasonal tropical systems can modify such patterns. Emergent and fine structural temporal patterns are adressed here for the first time for plant-frugivorous bird networks in a highly seasonal tropical environment. Methods. In a plant-frugivorous bird community, we analyzed the temporal turnover of bird species comprising the network core and periphery of ten temporal interaction networks resulting from different bird migration periods. Additionally, we evaluated how fruit abundance and richness, as well as the arrival of migratory birds into the system, explained the temporal changes in network parameters such as network size, connectance, nestedness, specialization, interaction strength asymmetry and niche overlap. The analysis included data from 10 quantitative plant-frugivorous bird networks registered from November 2013 to November 2014. Results. We registered a total of 319 interactions between 42 plant species and 44 frugivorous bird species; only ten bird species were part of the network core. We witnessed a noteworthy turnover of the species comprising the network periphery during migration periods, as opposed to the network core, which did not show significant temporal changes in species composition. Our results

  8. Modelling sugar diffusion across plant leaf cuticles: the effect of free water on substrate availability to phyllosphere bacteria.

    PubMed

    van der Wal, Annemieke; Leveau, Johan H J

    2011-03-01

    We present a continuous model for the diffusion of sugars across intact plant leaf cuticles. It is based on the flow of sugars from a source, representing the leaf apoplast, to a sink, in the shape of a hemispherical drop of water on the outside of the cuticle. Flow is a function of the difference between sugar concentrations C(Source) and C(Sink) , permeability P of the cuticle, volume V(Sink) of the water drop, as well as its contact angle α with the cuticle surface. Using a bacterial bioreporter for fructose, and a two-compartment experimental set-up consisting of isolated cuticles of walnut (Juglans regia) carrying water droplets while floating on solutions with increasing concentrations of fructose, we determined a value of 1 × 10⁻⁶ m h⁻¹ for P. Using this value, we explored different scenarios for the leaching of sugars across plant leaf cuticles to reveal in quantitative terms how diffusion takes longer when V(Sink) increases, P decreases or α increases. Bacterial growth was modelled as a function of changes in P, α and V(Sink) and was consistent with observations or suggestions from the literature in relation to the availability of free water on leaves. These results are discussed in the light of bacteria as ecosystem engineers, i.e. with the ability to modify the plant leaf surface environment in favour of their own survival, e.g. by increasing cuticle leakage or leaf wetness. Our model represents a first step towards a more comprehensive model which will enhance our quantitative understanding of the factors that play a role in nutrient availability to bacterial colonizers of the phyllosphere, or plant leaf surface. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  9. Biochar application to a contaminated soil reduces the availability and plant uptake of zinc, lead and cadmium.

    PubMed

    Puga, A P; Abreu, C A; Melo, L C A; Beesley, L

    2015-08-15

    Heavy metals in soil are naturally occurring but may be enhanced by anthropogenic activities such as mining. Bio-accumulation of heavy metals in the food chain, following their uptake to plants can increase the ecotoxicological risks associated with remediation of contaminated soils using plants. In the current experiment sugar cane straw-derived biochar (BC), produced at 700 °C, was applied to a heavy metal contaminated mine soil at 1.5%, 3.0% and 5.0% (w/w). Jack bean (Canavalia ensiformis) and Mucuna aterrima were grown in pots containing soil and biochar mixtures, and control pots without biochar. Pore water was sampled from each pot to confirm the effects of biochar on metal solubility, whilst soils were analyzed by DTPA extraction to confirm available metal concentrations. Leaves were sampled for SEM analysis to detect possible morphological and anatomical changes. The application of BC decreased the available concentrations of Cd, Pb and Zn in 56, 50 and 54% respectively, in the mine contaminated soil leading to a consistent reduction in the concentration of Zn in the pore water (1st collect: 99 to 39 μg L(-1), 2nd: 97 to 57 μg L(-1) and 3rd: 71 to 12 μg L(-1)). The application of BC reduced the uptake of Cd, Pb and Zn by plants with the jack bean translocating high proportions of metals (especially Cd) to shoots. Metals were also taken up by Mucuna aterrima but translocation to shoot was more limited than for jack bean. There were no differences in the internal structures of leaves observed by scanning electron microscopy. This study indicates that biochar application during mine soil remediation reduce plant concentrations of potential toxic metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. An improved protocol to study the plant cell wall proteome

    PubMed Central

    Printz, Bruno; Dos Santos Morais, Raphaël; Wienkoop, Stefanie; Sergeant, Kjell; Lutts, Stanley; Hausman, Jean-Francois; Renaut, Jenny

    2015-01-01

    Cell wall proteins were extracted from alfalfa stems according to a three-steps extraction procedure using sequentially CaCl2, EGTA, and LiCl-complemented buffers. The efficiency of this protocol for extracting cell wall proteins was compared with the two previously published methods optimized for alfalfa stem cell wall protein analysis. Following LC-MS/MS analysis the three-steps extraction procedure resulted in the identification of the highest number of cell wall proteins (242 NCBInr identifiers) and gave the lowest percentage of non-cell wall proteins (about 30%). However, the three protocols are rather complementary than substitutive since 43% of the identified proteins were specific to one protocol. This three-step protocol was therefore selected for a more detailed proteomic characterization using 2D-gel electrophoresis. With this technique, 75% of the identified proteins were shown to be fraction-specific and 72.7% were predicted as belonging to the cell wall compartment. Although, being less sensitive than LC-MS/MS approaches in detecting and identifying low-abundant proteins, gel-based approaches are valuable tools for the differentiation and relative quantification of protein isoforms and/or modified proteins. In particular isoforms, having variations in their amino-acid sequence and/or carrying different N-linked glycan chains were detected and characterized. This study highlights how the extracting protocols as well as the analytical techniques devoted to the study of the plant cell wall proteome are complementary and how they may be combined to elucidate the dynamism of the plant cell wall proteome in biological studies. Data are available via ProteomeXchange with identifier PXD001927. PMID:25914713

  11. High irradiance increases NH(4)(+) tolerance in Pisum sativum: Higher carbon and energy availability improve ion balance but not N assimilation.

    PubMed

    Ariz, Idoia; Artola, Ekhiñe; Asensio, Aaron Cabrera; Cruchaga, Saioa; Aparicio-Tejo, Pedro María; Moran, Jose Fernando

    2011-07-01

    The widespread use of NO(3)(-) fertilization has had a major ecological impact. NH(4)(+) nutrition may help to reduce this impact, although high NH(4)(+) concentrations are toxic for most plants. The underlying tolerance mechanisms are not yet fully understood, although they are thought to include the limitation of C, the disruption of ion homeostasis, and a wasteful NH(4)(+) influx/efflux cycle that carries an extra energetic cost for root cells. In this study, high irradiance (HI) was found to induce a notable tolerance to NH(4)(+) in the range 2.5-10mM in pea plants by inducing higher C availability, as shown by carbohydrate content. This capacity was accompanied by a general lower relative N content, indicating that tolerance is not achieved through higher net N assimilation on C-skeletons, and it was also not attributable to increased GS content or activity in roots or leaves. Moreover, HI plants showed higher ATP content and respiration rates. This extra energy availability is related to the internal NH(4)(+) content regulation (probably NH(4)(+) influx/efflux) and to an improvement of the cell ionic balance. The limited C availability at lower irradiance (LI) and high NH(4)(+) resulted in a series of metabolic imbalances, as reflected in a much higher organic acid content, thereby suggesting that the origin of the toxicity in plants cultured at high NH(4)(+) and LI is related to their inability to avoid large-scale accumulation of the NH(4)(+) ion.

  12. Nutritional improvement of plant foods by non-thermal processing.

    PubMed

    Knorr, D; Ade-Omowaye, B I O; Heinz, V

    2002-05-01

    As a result of the increasing consumer demand for minimally-processed fresh-like food products with high sensory and nutritional qualities, there is a growing interest in non-thermal processes for food processing and preservation. Key advanced technologies such as high-pressure processing, pulsed electric fields, dense gases and ultrasound are being applied to develop gentle but targeted processes to further improve the quality and safety of processed foods. These technologies also offer the potential for improving existing processes as well as for developing new process options. Furthermore, by adding new process dimensions (such as hydrostatic pressure, electric fields, ultrasonics, supercritical CO2) to the conventional process variables of temperature and time, they facilitate enlargement of the availability of unit operations. These operations might be applied effectively in unique combination processes, or as subsequent processing tools in more-targeted and subsequently less-intensive processes for food preservation and modification than the currently-applied processes.

  13. Effect of anaerobic digestion and liming on plant availability of phosphorus in iron- and aluminium-precipitated sewage sludge from primary wastewater treatment plants.

    PubMed

    Alvarenga, Emilio; Øgaard, Anne Falk; Vråle, Lasse

    2017-04-01

    More efficient plant utilisation of the phosphorus (P) in sewage sludge is required because rock phosphate is a limited resource. To meet environmental legislation thresholds for P removal from wastewater (WW), primary treatment with iron (Fe) or aluminium (Al) coagulants is effective. There is also a growing trend for WW treatment plants (WWTPs) to be coupled to a biogas process, in order to co-generate energy. The sludge produced, when stabilised, is used as a soil amendment in many countries. This study examined the effects of anaerobic digestion (AD), with or without liming as a post-treatment, on P release from Fe- and Al-precipitated sludges originating from primary WWTPs. Plant uptake of P from Fe- and Al-precipitated sludge after lime treatment but without AD was also compared. Chemical characterisation with sequential extraction of P and a greenhouse experiment with barley (Hordeum vulgare) were performed to assess the treatment effects on plant-available P. Liming increased the P-labile fraction in all cases. Plant P uptake increased from 18.5 mg pot(-1) to 53 mg P pot(-1) with liming of Fe-precipitated sludge and to 35 mg P pot(-1) with liming of the digestate, while it increased from 18.7 mg pot(-1) to 39 and 29 mg P pot(-1) for the Al-precipitated substrate and digestate, respectively. Thus, liming of untreated Fe-precipitated sludge and its digestate resulted in higher P uptake than liming its Al-precipitated counterparts. AD had a negative impact on P mobility for both sludges.

  14. What you can do to help improve regulation of the plants for planting pathway

    Treesearch

    Kerry O. Britton

    2008-01-01

    The current rules for plants for planting are being revised. The United States Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) has already provided several opportunities for public input into the new rules, and more opportunities will be coming soon. Considering the importance most plant health scientists attach to this issue, it is...

  15. Exploring high throughput phenotyping, plant architecture and plant-boll distribution for improving drought tolerance in cotton

    USDA-ARS?s Scientific Manuscript database

    There is a pressing need to identify and understand the effects of different irrigation regimes on plant-boll distribution, seed cotton yield, and plant architecture for improving yield and fiber quality under stress and/or drought tolerance of cotton (Gossypium spp.) cultivars. To identify the impa...

  16. Genetic Modification for Improving Seed Vigor Is Transitioning from Model Plants to Crop Plants

    PubMed Central

    Wu, Xiaolin; Ning, Fen; Hu, Xiuli; Wang, Wei

    2017-01-01

    Although seed vigor is a complex physiological trait controlled by quantitative trait loci, technological advances in the laboratory are being translated into applications for enhancing seed vigor in crop plants. In this article, we summarize and discuss pioneering work in the genetic modification of seed vigor, especially through the over-expression of protein L-isoaspartyl methyltransferase (PIMT, EC 2.1.1.77) in seeds. The impressive success in improving rice seed vigor through the over-expression of PIMT provides a valuable reference for engineering high-vigor seeds for crop production. In recent decades, numerous genes/proteins associated with seed vigor have been identified. It is hoped that such potential candidates may be used in the development of genetically edited crops for a high and stable yield potential in crop production. This possibility is very valuable in the context of a changing climate and increasing world population. PMID:28149305

  17. Genetic Modification for Improving Seed Vigor Is Transitioning from Model Plants to Crop Plants.

    PubMed

    Wu, Xiaolin; Ning, Fen; Hu, Xiuli; Wang, Wei

    2017-01-01

    Although seed vigor is a complex physiological trait controlled by quantitative trait loci, technological advances in the laboratory are being translated into applications for enhancing seed vigor in crop plants. In this article, we summarize and discuss pioneering work in the genetic modification of seed vigor, especially through the over-expression of protein L-isoaspartyl methyltransferase (PIMT, EC 2.1.1.77) in seeds. The impressive success in improving rice seed vigor through the over-expression of PIMT provides a valuable reference for engineering high-vigor seeds for crop production. In recent decades, numerous genes/proteins associated with seed vigor have been identified. It is hoped that such potential candidates may be used in the development of genetically edited crops for a high and stable yield potential in crop production. This possibility is very valuable in the context of a changing climate and increasing world population.

  18. Compressed Air System Upgrade Improves Production at an Automotive Glass Plant

    SciTech Connect

    Not Available

    2003-02-01

    In 2000, The Visteon automotive glass plant improved its compressed air system at its automotive glass plant in Nashville, Tennessee. This improvement allowed Visteon to save $711,000 annually, reduce annual energy consumption by 7.9 million kilowatt-hours, reduce maintenance, improve system performance, and avoid $800,000 in asbestos abatement costs.

  19. Improving forage quality and availability in the southern Great Plains with grasspea (Lathyrus sativus L.)

    USDA-ARS?s Scientific Manuscript database

    The rising cost of inorganic commercial fertilizer has renewed interest in introducing legumes into paddocks of tame grass. Legumes fix atmospheric nitrogen (N), which will be available to the legume and some will be available to the following non-legume crop, reducing the need for N fertilizers (Ba...

  20. Comparison of toxic heavy metals concentration in medicinal plants and their respective branded herbal formulations commonly available in Khyber Pakhtunkhwa.

    PubMed

    Shah, Waheed Ali; Zakiullah; Khuda, Fazli; Khan, Faridullah; Saeed, Muhammad

    2016-07-01

    The present study was conducted on fifteen medicinal plants and their respective branded formulations, commonly used in Khyber Pakhtunkhwa, for the evaluation of toxic heavy metals. The purpose of the study was to assess the toxic profile of the crude medicinal plants with respect to the worldwide permissible limits of metal concentrations and to correlate it with their respective herbal formulations available on the market. Chromium (Cr), Copper (Cu), Lead (Pb), Manganese (Mn) and Nickel (Ni) content were evaluated using wet digestion and Atomic Absorption Spectrophotometry technique. The results exhibited that in 100% of the analyzed medicinal plants Cr and Ni are present in excess of the maximum limits, Cu and Pb in 73% and 60% respectively, while Mn is in the normal range. Likewise in the respective branded formulations Cr and Ni exceed the normal limit in 100% of the products, Cu and Pb in 27% and 20% of the products respectively, while Mn is in the normal range. It indicates that majority of people in Pakistan who frequently use herbal drugs in various forms are exposed to the hazardous elements, which may pose serious health effects. Regulatory measures should therefore be taken to protect the general public from their hazardous health effects.

  1. Improved heliostat field design for solar tower plants

    NASA Astrophysics Data System (ADS)

    Collado, Francisco J.; Guallar, Jesús

    2017-06-01

    In solar power tower (SPT) systems, selecting the optimum location of thousands of heliostats and the most profitable tower height and receiver size remains a challenge. Campo code is prepared for the detailed design of such plants in particular, the optimum layout, provided that the plant size is known. Therefore, less exhaustive codes, as DELSOL3, are also needed to perform preliminary parametric analysis that narrows the most economic size of the plant.

  2. Neighbourhood structure and light availability influence the variations in plant design of shrubs in two cloud forests of different successional status

    PubMed Central

    Guzmán Q, J. Antonio; Cordero, Roberto A.

    2016-01-01

    Background and Aims Plant design refers to the construction of the plant body or its constituent parts in terms of form and function. Although neighbourhood structure is recognized as a factor that limits plant survival and species coexistence, its relative importance in plant design is not well understood. We conducted field research to analyse how the surrounding environment of neighbourhood structure and related effects on light availability are associated with changes in plant design in two understorey plants (Palicourea padifolia and Psychotria elata) within two successional stages of a cloud forest in Costa Rica. Methods Features of plant neighbourhood physical structure and light availability, estimated using hemispherical photographs, were used as variables that reflect the surrounding environment. Measures of plant biomechanics, allometry, branching and plant slenderness were used as functional plant attributes that reflect plant design. We propose a framework using a partial least squares path model and used it to test this association. Key Results The multidimensional response of plant design of these species suggests that decreases in the height-based factor of safety and increases in mechanical load and developmental stability are influenced by increases in maximum height of neighbours and a distance-dependence interference index more than neighbourhood plant density or neighbour aggregation. Changes in plant branching and slenderness are associated positively with light availability and negatively with canopy cover. Conclusions Although it has been proposed that plant design varies according to plant density and light availability, we found that neighbour size and distance-dependence interference are associated with changes in biomechanics, allometry and branching, and they must be considered as key factors that contribute to the adaptation and coexistence of these plants in this highly diverse forest community. PMID:27245635

  3. Temporal changes in the structure of a plant-frugivore network are influenced by bird migration and fruit availability

    PubMed Central

    Andresen, Ellen; Díaz-Castelazo, Cecilia

    2016-01-01

    Background. Ecological communities are dynamic collections whose composition and structure change over time, making up complex interspecific interaction networks. Mutualistic plant–animal networks can be approached through complex network analysis; these networks are characterized by a nested structure consisting of a core of generalist species, which endows the network with stability and robustness against disturbance. Those mutualistic network structures can vary as a consequence of seasonal fluctuations and food availability, as well as the arrival of new species into the system that might disorder the mutualistic network structure (e.g., a decrease in nested pattern). However, there is no assessment on how the arrival of migratory species into seasonal tropical systems can modify such patterns. Emergent and fine structural temporal patterns are adressed here for the first time for plant-frugivorous bird networks in a highly seasonal tropical environment. Methods. In a plant-frugivorous bird community, we analyzed the temporal turnover of bird species comprising the network core and periphery of ten temporal interaction networks resulting from different bird migration periods. Additionally, we evaluated how fruit abundance and richness, as well as the arrival of migratory birds into the system, explained the temporal changes in network parameters such as network size, connectance, nestedness, specialization, interaction strength asymmetry and niche overlap. The analysis included data from 10 quantitative plant-frugivorous bird networks registered from November 2013 to November 2014. Results. We registered a total of 319 interactions between 42 plant species and 44 frugivorous bird species; only ten bird species were part of the network core. We witnessed a noteworthy turnover of the species comprising the network periphery during migration periods, as opposed to the network core, which did not show significant temporal changes in species composition. Our

  4. Engineering plants for animal feed for improved nutritional value.

    PubMed

    Williams, Peter E V

    2003-05-01

    Feed formulation to meet nutritional requirements of livestock is becoming increasingly challenging. Regulations have banned the use of traditional high-quality protein supplements such as meat-and-bone meal, pollution from animal excreta of N and P is an issue and antibiotics are no longer available as insurance against the impact of enteric infection and feed anti-nutritional factors. The improved genetic potential of livestock is increasing daily requirement for energy and protein (essential amino acids). To benefit from the enhanced growth potential of livestock diets with high nutrient density are needed that can be formulated from crops without increased cost. Genetic modification of commodity crops used to manufacture animal feed in order to improve the density and quality of available nutrients is a potential solution to some of these problems. Furthermore, crops may be used as biofactories to produce molecules and products used in animal feed with considerable reductions in manufacturing fixed costs. Nevertheless, there are considerable not insurmountable challenges, such as the creation of sufficient economic value to deliver benefit to all members in the feed production chain, which is an essential element of identity preserving and delivering the technology to livestock producers. Individual output traits in the major commodity crops may not provide sufficient value to adequately compensate all the members of the feed production chain. Successful adoption of output traits may rely on inserting combinations of agronomic input traits with specific quality traits or increasing the value proposition by inserting combinations of output traits.

  5. Comparison of the Insecticidal Characteristics of Commercially Available Plant Essential Oils Against Aedes aegypti and Anopheles gambiae (Diptera: Culicidae).

    PubMed

    Norris, Edmund J; Gross, Aaron D; Dunphy, Brendan M; Bessette, Steven; Bartholomay, Lyric; Coats, Joel R

    2015-09-01

    Aedes aegypti and Anopheles gambiae are two mosquito species that represent significant threats to global public health as vectors of Dengue virus and malaria parasites, respectively. Although mosquito populations have been effectively controlled through the use of synthetic insecticides, the emergence of widespread insecticide-resistance in wild mosquito populations is a strong motivation to explore new insecticidal chemistries. For these studies, Ae. aegypti and An. gambiae were treated with commercially available plant essential oils via topical application. The relative toxicity of each essential oil was determined, as measured by the 24-h LD(50) and percentage knockdown at 1 h, as compared with a variety of synthetic pyrethroids. For Ae. aegypti, the most toxic essential oil (patchouli oil) was ∼1,700-times less toxic than the least toxic synthetic pyrethroid, bifenthrin. For An. gambiae, the most toxic essential oil (patchouli oil) was ∼685-times less toxic than the least toxic synthetic pyrethroid. A wide variety of toxicities were observed among the essential oils screened. Also, plant essential oils were analyzed via gas chromatography/mass spectrometry (GC/MS) to identify the major components in each of the samples screened in this study. While the toxicities of these plant essential oils were demonstrated to be lower than those of the synthetic pyrethroids tested, the large amount of GC/MS data and bioactivity data for each essential oil presented in this study will serve as a valuable resource for future studies exploring the insecticidal quality of plant essential oils. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. 77 FR 41367 - Dow AgroSciences LLC; Availability of Petition, Plant Pest Risk Assessment, and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ..., ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or... produced through genetic engineering that are plant pests or that there is reason to believe are plant...

  7. Challenges and opportunities for improving food quality and nutrition through plant biotechnology.

    PubMed

    Francis, David; Finer, John J; Grotewold, Erich

    2017-04-01

    Plant biotechnology has been around since the advent of humankind, resulting in tremendous improvements in plant cultivation through crop domestication, breeding and selection. The emergence of transgenic approaches involving the introduction of defined DNA sequences into plants by humans has rapidly changed the surface of our planet by further expanding the gene pool used by plant breeders for plant improvement. Transgenic approaches in food plants have raised concerns on the merits, social implications, ecological risks and true benefits of plant biotechnology. The recently acquired ability to precisely edit plant genomes by modifying native genes without introducing new genetic material offers new opportunities to rapidly exploit natural variation, create new variation and incorporate changes with the goal to generate more productive and nutritious plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The Virtual Genetics Lab II: Improvements to a Freely Available Software Simulation of Genetics

    ERIC Educational Resources Information Center

    White, Brian T.

    2012-01-01

    The Virtual Genetics Lab II (VGLII) is an improved version of the highly successful genetics simulation software, the Virtual Genetics Lab (VGL). The software allows students to use the techniques of genetic analysis to design crosses and interpret data to solve realistic genetics problems involving a hypothetical diploid insect. This is a brief…

  9. The Virtual Genetics Lab II: Improvements to a Freely Available Software Simulation of Genetics

    ERIC Educational Resources Information Center

    White, Brian T.

    2012-01-01

    The Virtual Genetics Lab II (VGLII) is an improved version of the highly successful genetics simulation software, the Virtual Genetics Lab (VGL). The software allows students to use the techniques of genetic analysis to design crosses and interpret data to solve realistic genetics problems involving a hypothetical diploid insect. This is a brief…

  10. Ecosystem responses to warming-induced plant species loss and increased nitrogen availability in a Rocky Mountain subalpine meadow

    NASA Astrophysics Data System (ADS)

    Smith, Molly Elizabeth

    Climate change is predicted to be an important driver of future biodiversity changes, especially in mountainous environments. Climate warming-induced plant species loss is likely to be non-random and based on species-specific susceptibility to rising temperatures. Experimental warming results from a subalpine meadow in Colorado suggest that warming adversely affects shallow-rooted forb species in this ecosystem. To examine the ecological consequences of losing this warming-sensitive species group, I experimentally removed all shallow-rooted forb species from otherwise intact subalpine meadow plots. Since experimental warming also resulted in increased soil nitrogen availability, I crossed the removal treatment with a nitrogen addition treatment to determine whether the loss of shallow-rooted forbs altered the community's response to a perturbation in nitrogen availability. After three years of experimental species removal, tap-rooted forbs and grasses were able to fully compensate for the loss of shallow-rooted forbs with increased biomass production. Moreover, the remaining plant community yielded a larger biomass response to nitrogen addition when shallow-rooted forbs were removed, possibly because removal led to increased soil moisture. The loss of shallow-rooted forbs and addition of nitrogen did not have strong effects on nitrogen cycling beyond increases in the amount of nitrate moving down through the soil profile. Uptake of nitrogen into plant tissue was also not affected by either the shallow-rooted forb removal or nitrogen addition treatments, suggesting that nitrogen may not have been the most limiting resource during the experiment. I found that spatial heterogeneity generally had a greater influence on soil microbial community composition than any of the experimental treatments. I conclude that the warming-induced loss of shallow-rooted forbs did not affect biomass production, nitrogen cycling, or soil microbial community composition, but did increase

  11. 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.

  12. Environmental regulation of carbon isotope composition and crassulacean acid metabolism in three plant communities along a water availability gradient

    PubMed Central

    Ricalde, M. Fernanda; Durán, Rafael; Dupuy, Juan Manuel; Simá, J. Luis; Us-Santamaría, Roberth; Santiago, Louis S.

    2010-01-01

    Expression of crassulacean acid metabolism (CAM) is characterized by extreme variability within and between taxa and its sensitivity to environmental variation. In this study, we determined seasonal fluctuations in CAM photosynthesis with measurements of nocturnal tissue acidification and carbon isotopic composition (δ13C) of bulk tissue and extracted sugars in three plant communities along a precipitation gradient (500, 700, and 1,000 mm year−1) on the Yucatan Peninsula. We also related the degree of CAM to light habitat and relative abundance of species in the three sites. For all species, the greatest tissue acid accumulation occurred during the rainy season. In the 500 mm site, tissue acidification was greater for the species growing at 30% of daily total photon flux density (PFD) than species growing at 80% PFD. Whereas in the two wetter sites, the species growing at 80% total PFD had greater tissue acidification. All species had values of bulk tissue δ13C less negative than −20‰, indicating strong CAM activity. The bulk tissue δ13C values in plants from the 500 mm site were 2‰ less negative than in plants from the wetter sites, and the only species growing in the three communities, Acanthocereus tetragonus (Cactaceae), showed a significant negative relationship between both bulk tissue and sugar δ13C values and annual rainfall, consistent with greater CO2 assimilation through the CAM pathway with decreasing water availability. Overall, variation in the use of CAM photosynthesis was related to water and light availability and CAM appeared to be more ecologically important in the tropical dry forests than in the coastal dune. PMID:20652592

  13. Environmental regulation of carbon isotope composition and crassulacean acid metabolism in three plant communities along a water availability gradient.

    PubMed

    Ricalde, M Fernanda; Andrade, José Luis; Durán, Rafael; Dupuy, Juan Manuel; Simá, J Luis; Us-Santamaría, Roberth; Santiago, Louis S

    2010-12-01

    Expression of crassulacean acid metabolism (CAM) is characterized by extreme variability within and between taxa and its sensitivity to environmental variation. In this study, we determined seasonal fluctuations in CAM photosynthesis with measurements of nocturnal tissue acidification and carbon isotopic composition (δ(13)C) of bulk tissue and extracted sugars in three plant communities along a precipitation gradient (500, 700, and 1,000 mm year(-1)) on the Yucatan Peninsula. We also related the degree of CAM to light habitat and relative abundance of species in the three sites. For all species, the greatest tissue acid accumulation occurred during the rainy season. In the 500 mm site, tissue acidification was greater for the species growing at 30% of daily total photon flux density (PFD) than species growing at 80% PFD. Whereas in the two wetter sites, the species growing at 80% total PFD had greater tissue acidification. All species had values of bulk tissue δ(13)C less negative than -20‰, indicating strong CAM activity. The bulk tissue δ(13)C values in plants from the 500 mm site were 2‰ less negative than in plants from the wetter sites, and the only species growing in the three communities, Acanthocereus tetragonus (Cactaceae), showed a significant negative relationship between both bulk tissue and sugar δ(13)C values and annual rainfall, consistent with greater CO(2) assimilation through the CAM pathway with decreasing water availability. Overall, variation in the use of CAM photosynthesis was related to water and light availability and CAM appeared to be more ecologically important in the tropical dry forests than in the coastal dune.

  14. Herbaceous Weed Control Improves Survival of Planted Shumard Oak Seedlings

    Treesearch

    A.W. Ezell; J.D. Hodges

    2002-01-01

    Shumard oak seedlings were planted on a cutoversite in the Mississippi River floodplain, which had received both chemical and mechanical site preparation treatments. Soil at the site was a commerce silt loam and the elevation was such that the area does not flood. Planting stock was 1-0, bareroot seedlings. A total of seven active herbicide treatments were applied at a...

  15. Improved stereo matching applied to digitization of greenhouse plants

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Xu, Lihong; Li, Dawei; Gu, Xiaomeng

    2015-03-01

    The digitization of greenhouse plants is an important aspect of digital agriculture. Its ultimate aim is to reconstruct a visible and interoperable virtual plant model on the computer by using state-of-the-art image process and computer graphics technologies. The most prominent difficulties of the digitization of greenhouse plants include how to acquire the three-dimensional shape data of greenhouse plants and how to carry out its realistic stereo reconstruction. Concerning these issues an effective method for the digitization of greenhouse plants is proposed by using a binocular stereo vision system in this paper. Stereo vision is a technique aiming at inferring depth information from two or more cameras; it consists of four parts: calibration of the cameras, stereo rectification, search of stereo correspondence and triangulation. Through the final triangulation procedure, the 3D point cloud of the plant can be achieved. The proposed stereo vision system can facilitate further segmentation of plant organs such as stems and leaves; moreover, it can provide reliable digital samples for the visualization of greenhouse tomato plants.

  16. Evaluation of protein pattern changes in roots and leaves of Zea mays plants in response to nitrate availability by two-dimensional gel electrophoresis analysis

    PubMed Central

    Prinsi, Bhakti; Negri, Alfredo S; Pesaresi, Paolo; Cocucci, Maurizio; Espen, Luca

    2009-01-01

    Background Nitrogen nutrition is one of the major factors that limit growth and production of crop plants. It affects many processes, such as development, architecture, flowering, senescence and photosynthesis. Although the improvement in technologies for protein study and the widening of gene sequences have made possible the study of the plant proteomes, only limited information on proteome changes occurring in response to nitrogen amount are available up to now. In this work, two-dimensional gel electrophoresis (2-DE) has been used to investigate the protein changes induced by NO3- concentration in both roots and leaves of maize (Zea mays L.) plants. Moreover, in order to better evaluate the proteomic results, some biochemical and physiological parameters were measured. Results Through 2-DE analysis, 20 and 18 spots that significantly changed their amount at least two folds in response to nitrate addition to the growth medium of starved maize plants were found in roots and leaves, respectively. Most of these spots were identified by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS). In roots, many of these changes were referred to enzymes involved in nitrate assimilation and in metabolic pathways implicated in the balance of the energy and redox status of the cell, among which the pentose phosphate pathway. In leaves, most of the characterized proteins were related to regulation of photosynthesis. Moreover, the up-accumulation of lipoxygenase 10 indicated that the leaf response to a high availability of nitrate may also involve a modification in lipid metabolism. Finally, this proteomic approach suggested that the nutritional status of the plant may affect two different post-translational modifications of phosphoenolpyruvate carboxylase (PEPCase) consisting in monoubiquitination and phosphorylation in roots and leaves, respectively. Conclusion This work provides a first characterization of the proteome changes that occur in

  17. Nutrient availability and nutrient use efficiency in plants growing in the transition zone between land and water.

    PubMed

    Cavalli, G; Baattrup-Pedersen, A; Riis, T

    2016-03-01

    The transition zone between terrestrial and freshwater habitats is highly dynamic, with large variability in environmental characteristics. Here, we investigate how these characteristics influence the nutritional status and performance of plant life forms inhabiting this zone. Specifically, we hypothesised that: (i) tissue nutrient content differs among submerged, amphibious and terrestrial species, with higher content in submerged species; and (ii) PNUE gradually increases from submerged over amphibious to terrestrial species, reflecting differences in the availability of N and P relative to inorganic C across the land-water ecotone. We found that tissue nutrient content was generally higher in submerged species and C:N and C:P ratios indicated that content was limiting for growth for ca. 20% of plant individuals, particularly those belonging to amphibious and terrestrial species groups. As predicted, the PNUE increased from submerged over amphibious to terrestrial species. We suggest that this pattern reflects that amphibious and terrestrial species allocate proportionally more nutrients into processes of importance for photosynthesis at saturating CO2 availability, i.e. enzymes involved in substrate regeneration, compared to submerged species that are acclimated to lower availability of CO2 in the aquatic environment. Our results indicate that enhanced nutrient loading may affect relative abundance of the three species groups in the land-water ecotone of stream ecosystems. Thus, species of amphibious and terrestrial species groups are likely to benefit more from enhanced nutrient availability in terms of faster growth compared to aquatic species, and that this can be detrimental to aquatic species growing in the land-water ecotone, e.g. Ranunculus and Callitriche. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. A Method to Quantify Plant Availability and Initiating Event Frequency Using a Large Event Tree, Small Fault Tree Model

    SciTech Connect

    Kee, Ernest J.; Sun, Alice; Rodgers, Shawn; Popova, ElmiraV; Nelson, Paul; Moiseytseva, Vera; Wang, Eric

    2006-07-01

    South Texas Project uses a large fault tree to produce scenarios (minimal cut sets) used in quantification of plant availability and event frequency predictions. On the other hand, the South Texas Project probabilistic risk assessment model uses a large event tree, small fault tree for quantifying core damage and radioactive release frequency predictions. The South Texas Project is converting its availability and event frequency model to use a large event tree, small fault in an effort to streamline application support and to provide additional detail in results. The availability and event frequency model as well as the applications it supports (maintenance and operational risk management, system engineering health assessment, preventive maintenance optimization, and RIAM) are briefly described. A methodology to perform availability modeling in a large event tree, small fault tree framework is described in detail. How the methodology can be used to support South Texas Project maintenance and operations risk management is described in detail. Differences with other fault tree methods and other recently proposed methods are discussed in detail. While the methods described are novel to the South Texas Project Risk Management program and to large event tree, small fault tree models, concepts in the area of application support and availability modeling have wider applicability to the industry. (authors)

  19. Biochar may physically entrap nitrate during field aging or co-composting which become plant available under controlled conditions

    NASA Astrophysics Data System (ADS)

    Haider, Ghulam; Steffens, Diedrich; Müller, Christoph; Kammann, Claudia

    2017-04-01

    Conversion of organic biomass (agriculture/forestry residues) to biochar (BC) for carbon sequestration in soil to abate global warming has received much attention in recent years. However, apart from carbon sequestration, the incorporation of freshly produced biochars in agricultural soils have shown varying effects on soil-plant-moisture and nutrient interactions. It has been frequently reported that BC amendment may accelerate soil N transformations, reduce nitrate leaching, increase nutrient availability and soil fertility thereby increase crop yields by 10-15%. In addition, recent meta-studies suggested that BC-nitrogen (N) interactions in agricultural soils have the potential to reduce nitrous oxide (N2O) emissions by 50% with the underlying mechanisms not well understood. Also, mechanisms of BC-N sorption and desorption or plant availability of captured N in BC remain poorly understood. In this study we conducted two different experiments aiming (a) to understand the mechanism of nitrate capture by field aged (>3 years) BC (wood chip, pruning, bark and leaves (550-600°C)) and (b) to test the availability of captured nitrate by field-aged and composted BC to plants (quinoa, ryegrass) in a pot study under controlled conditions. Experiment (A): We hypothesized that N captured in the pores of BC may remain inaccessible to extraction solutions due to clogging of BC pores by the development of hydrophobic layer on BC surface following oxidation under field conditions. Therefore (i) physically breaking the structure or (ii) exerting under-pressure to water-immersed aged BC particles may allow extracting greater nitrate with the standard 2 M KCl method compared to intact particles. Study (A) encompassed 1) extraction from intact field-aged BC particles, 2) extraction after immersion in water and evacuation in vacutainers, 3) extraction after grinding of BC to powder and 4) prolonged shaking (48 hours at 80°C) of intact field aged BC particles and then extraction

  20. Ectopic expression of a soybean phytase in developing seeds of Glycine max to improve phosphorus availability.

    PubMed

    Chiera, Joseph M; Finer, John J; Grabau, Elizabeth A

    2004-12-01

    A transgenic approach was used to alter soybean seed phytate content by expressing a soybean phytase gene (GmPhy) during seed development to degrade accumulating phytic acid (IP6). An expression vector containing the soybean phytase cDNA controlled by the seed-specific beta-conglycinin promoter (alpha'-subunit) was used to transform embryogenic soybean cultures. Plants from four independent transgenic lines were analyzed for transgene integration and seed IP6 levels. The reduction in IP6 levels in transgenic seeds compared to control 'Jack' soybeans ranged from 12.6 to 24.8 as determined by HPLC. A low copy transformant was propagated to the T4 generation and examined in more detail for phytase expression and enzyme activity during seed development. Expression of phytase mRNA and phytase activity increased during seed development, consistent with the use of an embryo-specific promoter. Ectopic phytase expression during seed development offers potential as an effective strategy for reducing phytate content in soybean seed.

  1. A natural plant growth promoter calliterpenone from a plant Callicarpa macrophylla Vahl improves the plant growth promoting effects of plant growth promoting rhizobacteria (PGPRs).

    PubMed

    Maji, Deepamala; Barnawal, Deepti; Gupta, Aakansha; King, Shikha; Singh, A K; Kalra, A

    2013-05-01

    Experiments were conducted to evaluate the efficacy of calliterpenone, a natural plant growth promoter from a shrub Callicarpa macrophylla Vahl., in enhancing the growth and yield promoting effects of plant growth promoting rhizobacteria (PGPRs), in menthol mint (Mentha arvensis L).This study is based on our previous results indicating the microbial growth promotion by calliterpenone and assumption that application of calliterpenone along with PGPRs will improve the population of PGPRs resulting in higher impacts on plant growth and yield. Of the 15 PGPRs (identified as potent ones in our laboratory), 25 μl of 0.01 mM calliterpenone (8.0 μg/100 ml) was found to be useful in improving the population of nine PGPRs in culture media. The five selected strains of PGPRs exhibiting synergy with calliterpenone in enhancing growth of maize compared to PGPR or calliterpenone alone were selected and tested on two cultivars (cvs. Kosi and Kushal) of M. arvensis. Of the five strains, Bacillus subtilis P-20 (16S rDNA sequence homologous to Accession No NR027552) and B. subtilis Daz-26 (16SrDNA sequence homologuos to Accession No GU998816) were found to be highly effective in improving the herb and essential oil yield in the cultivars Kushal and Kosi respectively when co-treated with calliterpenone. The results open up the possibilities of using a natural growth promoter along with PGPRs as a bio-agri input for sustainable and organic agriculture.

  2. Plant canopy gap-size analysis theory for improving optical measurements of leaf-area index

    NASA Astrophysics Data System (ADS)

    Chen, Jing M.; Cihlar, Josef

    1995-09-01

    Optical instruments currently available for measuring the leaf-area index (LAI) of a plant canopy all utilize only the canopy gap-fraction information. These instruments include the Li-Cor LAI-2000 Plant Canopy Analyzer, Decagon, and Demon. The advantages of utilizing both the canopy gap-fraction and gap-size information are shown. For the purpose of measuring the canopy gap size, a prototype sunfleck-LAI instrument named Tracing Radiation and Architecture of Canopies (TRAC), has been developed and tested in two pure conifer plantations, red pine (Pinus resinosa Ait.) and jack pine (Pinus banksiana Lamb). A new gap-size-analysis theory is presented to quantify the effect of canopy architecture on optical measurements of LAI based on the gap-fraction principle. The theory is an improvement on that of Lang and Xiang [Agric. For. Meteorol. 37, 229 (1986)]. In principle, this theory can be used for any heterogeneous canopies.

  3. Formosa Plastics Corporation: Plant-Wide Assessment of Texas Plant Identifies Opportunities for Improving Process Efficiency and Reducing Energy Costs

    SciTech Connect

    2005-01-01

    At Formosa Plastics Corporation's plant in Point Comfort, Texas, a plant-wide assessment team analyzed process energy requirements, reviewed new technologies for applicability, and found ways to improve the plant's energy efficiency. The assessment team identified the energy requirements of each process and compared actual energy consumption with theoretical process requirements. The team estimated that total annual energy savings would be about 115,000 MBtu for natural gas and nearly 14 million kWh for electricity if the plant makes several improvements, which include upgrading the gas compressor impeller, improving the vent blower system, and recovering steam condensate for reuse. Total annual cost savings could be $1.5 million. The U.S. Department of Energy's Industrial Technologies Program cosponsored this assessment.

  4. Crop Improvement through Modification of the Plant's Own Genome

    PubMed Central

    Rommens, Caius M.; Humara, Jaime M.; Ye, Jingsong; Yan, Hua; Richael, Craig; Zhang, Lynda; Perry, Rachel; Swords, Kathleen

    2004-01-01

    Plant genetic engineering has, until now, relied on the incorporation of foreign DNA into plant genomes. Public concern about the extent to which transgenic crops differ from their traditionally bred counterparts has resulted in molecular strategies and gene choices that limit, but not eliminate, the introduction of foreign DNA. Here, we demonstrate that a plant-derived (P-) DNA fragment can be used to replace the universally employed Agrobacterium transfer (T-) DNA. Marker-free P-DNAs are transferred to plant cell nuclei together with conventional T-DNAs carrying a selectable marker gene. By subsequently linking a positive selection for temporary marker gene expression to a negative selection against marker gene integration, 29% of derived regeneration events contain P-DNA insertions but lack any copies of the T-DNA. Further refinements are accomplished by employing Ω-mutated virD2 and isopentenyl transferase cytokinin genes to impair T-DNA integration and select against backbone integration, respectively. The presented methods are used to produce hundreds of marker-free and backbone-free potato (Solanum tuberosum) plants displaying reduced expression of a tuber-specific polyphenol oxidase gene in potato. The modified plants represent the first example of genetically engineered plants that only contain native DNA. PMID:15133156

  5. Plant compensatory growth in aspen seedlings: the role of frequency and intensity of herbivory and resource availability

    Treesearch

    Nadir Erbilgin; David A. Galvez; Bin Zhang

    2012-01-01

    Plant ecologists have debated the mechanisms used by plants to cope with the impact of herbivore damage for more than a century. During that time, plant resistance mechanisms, which reduce the amount of herbivore damage before and during herbivory, have received most of the attention, while plant tolerance mechanisms, which may minimize the impacts of damage after...

  6. Exogenous treatments with phytohormones can improve growth and nickel yield of hyperaccumulating plants.

    PubMed

    Cabello-Conejo, M I; Prieto-Fernández, A; Kidd, P S

    2014-10-01

    The application of plant growth regulators (PGRs) or phytohormones could be an interesting option for stimulating biomass production of hyperaccumulating plants and, consequently, their metal phytoextraction capacity. The effect of exogenous applications of phytohormones (PGR) on the Ni phytoextraction capacity of four Ni hyperaccumulating species (Alyssum corsicum, Alyssum malacitanum, Alyssum murale and Noccaea goesingense) was evaluated. Four different commercially available phytohormones (B, C, K and P) based on gibberellins, cytokinins and auxins were applied to the plant aerial tissues. Each product was applied at three different concentrations (B1-3, C1-3, K1-3 and P1-3). The effect on biomass production was dependent on the species, the PGR type and the concentration at which it was applied. Two of the four products (K and P) consistently increased biomass production compared to untreated control plants in all four plant species. On the other hand, all four products led to a significant increase in the number of branches (and leaves in the case of N. goesingense) of all four species compared to control plants. Application of phytohormones generally led to a reduction in shoot Ni concentration. Nonetheless, in some cases as a consequence of the increase observed in biomass after the application of phytohormones a significant increase in the Ni phytoextraction efficiency was also observed (but this was species- and PGR type-dependent). The results show that PGRs can be successfully used to improve the growth and biomass production of hyperaccumulating species such as Alyssum and Noccaea. However, an increase in biomass did not always lead to a higher Ni removal, and the most effective PGR for increasing Ni removal was the IAA-based product. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Improving Agricultural Productivity in Tonga through Ensuring Data Availability and Enhancing Agro-meteorological Services

    NASA Astrophysics Data System (ADS)

    Kim, K. H.

    2015-12-01

    The project was first conceived in the Global Framework for Climate Services Regional Consultation in the Cook Islands in March 2014. In this meeting, key officials from the Ministry of Agriculture and Food, Forests, and Fisheries and the Tonga Meteorological Services had a meeting with the APEC Climate Center scientists with the idea to collaborate on a joint project. The project evolved to include the following components: assessment of users' needs and capacities, development of an agricultural database, research on the core relationships between agriculture and climate through modeling and field trials, and the development and delivery of agro-meteorological services. Envisioned outputs include a 2-7 day warning for pests and diseases, a suite of tools supporting decisions on planting dates and crop varieties, and other advisory services derived from seasonal climate forecasts. As one of the climate adaptation projects under its Pacific Island portfolio, the project will deliver urgent information services for Tongan agricultural growers and exporters. The project comes into greater importance and urgency, as the 2014 drought event resulted in the destruction of 80% of squash in Tonga, a main export crop from which the country derives foreign exchange earnings. Since 2014, some of the project achievements include the first agro-met data collection in Tonga, the development of an agricultural DB management system that houses archived agriculture data, and key meetings with stakeholders to ensure alignment of the project objectives and design with the interests of the Tongan government and other stakeholders. In addition, rigorous scientific research through modeling and field trials has been conducted to address the twin goals of supporting Tonga's economy as well as food security. Based on the findings from the research, tools will be developed to translate the science into knowledge that supports decisions on the farm scale.

  8. Randomized Trial of the Availability, Responsiveness and Continuity (ARC) Organizational Intervention for Improving Youth Outcomes in Community Mental Health Programs

    ERIC Educational Resources Information Center

    Glisson, Charles; Hemmelgarn, Anthony; Green, Philip; Williams, Nathaniel J.

    2013-01-01

    Objectives: The primary objective of the study was to assess whether the Availability, Responsiveness and Continuity (ARC) organizational intervention improved youth outcomes in community based mental health programs. The second objective was to assess whether programs with more improved organizational social contexts following the 18-month ARC…

  9. Randomized Trial of the Availability, Responsiveness and Continuity (ARC) Organizational Intervention for Improving Youth Outcomes in Community Mental Health Programs

    ERIC Educational Resources Information Center

    Glisson, Charles; Hemmelgarn, Anthony; Green, Philip; Williams, Nathaniel J.

    2013-01-01

    Objectives: The primary objective of the study was to assess whether the Availability, Responsiveness and Continuity (ARC) organizational intervention improved youth outcomes in community based mental health programs. The second objective was to assess whether programs with more improved organizational social contexts following the 18-month ARC…

  10. Does information available at admission for delivery improve prediction of vaginal birth after cesarean?

    PubMed Central

    Grobman, William A.; Lai, Yinglei; Landon, Mark B.; Spong, Catherine Y.; Leveno, Kenneth J.; Rouse, Dwight J.; Varner, Michael W.; Moawad, Atef H.; Simhan, Hyagriv N.; Harper, Margaret; Wapner, Ronald J.; Sorokin, Yoram; Miodovnik, Menachem; Carpenter, Marshall; O'sullivan, Mary J.; Sibai, Baha M.; Langer, Oded; Thorp, John M.; Ramin, Susan M.; Mercer, Brian M.

    2010-01-01

    Objective To construct a predictive model for vaginal birth after cesarean (VBAC) that combines factors that can be ascertained only as the pregnancy progresses with those known at initiation of prenatal care. Study design Using multivariable modeling, we constructed a predictive model for VBAC that included patient factors known at the initial prenatal visit as well as those that only became evident as the pregancy progressed to the admission for delivery. Results 9616 women were analyzed. The regression equation for VBAC success included multiple factors that could not be known at the first prenatal visit. The area under the curve for this model was significantly greater (P < .001) than that of a model that included only factors available at the first prenatal visit. Conclusion A prediction model for VBAC success that incorporates factors that can be ascertained only as the pregnancy progresses adds to the predictive accuracy of a model that uses only factors available at a first prenatal visit. PMID:19813165

  11. Does information available at admission for delivery improve prediction of vaginal birth after cesarean?

    PubMed

    Grobman, William A; Lai, Yinglei; Landon, Mark B; Spong, Catherine Y; Leveno, Kenneth J; Rouse, Dwight J; Varner, Michael W; Moawad, Atef H; Simhan, Hyagriv N; Harper, Margaret; Wapner, Ronald J; Sorokin, Yoram; Miodovnik, Menachem; Carpenter, Marshall; O'Sullivan, Mary J; Sibai, Baha M; Langer, Oded; Thorp, John M; Ramin, Susan M; Mercer, Brian M

    2009-11-01

    We sought to construct a predictive model for vaginal birth after cesarean (VBAC) that combines factors that can be ascertained only as the pregnancy progresses with those known at initiation of prenatal care. Using multivariable modeling, we constructed a predictive model for VBAC that included patient factors known at the initial prenatal visit as well as those that only become evident as the pregnancy progresses to the admission for delivery. We analyzed 9616 women. The regression equation for VBAC success included multiple factors that could not be known at the first prenatal visit. The area under the curve for this model was significantly greater ( P < 0.001) than that of a model that included only factors available at the first prenatal visit. A prediction model for VBAC success, which incorporates factors that can be ascertained only as the pregnancy progresses, adds to the predictive accuracy of a model that uses only factors available at a first prenatal visit.

  12. Silicon-mediated Improvement in Plant Salinity Tolerance: The Role of Aquaporins.

    PubMed

    Rios, Juan J; Martínez-Ballesta, Maria C; Ruiz, Juan M; Blasco, Begoña; Carvajal, Micaela

    2017-01-01

    Silicon (Si) is an abundant and differentially distributed element in soils that is believed to have important biological functions. However, the benefits of Si and its essentiality in plants are controversial due to differences among species in their ability to take up this element. Despite this, there is a consensus that the application of Si improves the water status of plants under abiotic stress conditions. Hence, plants treated with Si are able to maintain a high stomatal conductance and transpiration rate under salt stress, suggesting that a reduction in Na(+) uptake occurs due to deposition of Si in the root. In addition, root hydraulic conductivity increases when Si is applied. As a result, a Si-mediated upregulation of aquaporin (PIP) gene expression is observed in relation to increased root hydraulic conductivity and water uptake. Aquaporins of the subclass nodulin 26-like intrinsic proteins are further involved in allowing Si entry into the cell. Therefore, on the basis of available published results and recent developments, we propose a model to explain how Si absorption alleviates stress in plants grown under saline conditions through the conjugated action of different aquaporins.

  13. Silicon-mediated Improvement in Plant Salinity Tolerance: The Role of Aquaporins

    PubMed Central

    Rios, Juan J.; Martínez-Ballesta, Maria C.; Ruiz, Juan M.; Blasco, Begoña; Carvajal, Micaela

    2017-01-01

    Silicon (Si) is an abundant and differentially distributed element in soils that is believed to have important biological functions. However, the benefits of Si and its essentiality in plants are controversial due to differences among species in their ability to take up this element. Despite this, there is a consensus that the application of Si improves the water status of plants under abiotic stress conditions. Hence, plants treated with Si are able to maintain a high stomatal conductance and transpiration rate under salt stress, suggesting that a reduction in Na+ uptake occurs due to deposition of Si in the root. In addition, root hydraulic conductivity increases when Si is applied. As a result, a Si-mediated upregulation of aquaporin (PIP) gene expression is observed in relation to increased root hydraulic conductivity and water uptake. Aquaporins of the subclass nodulin 26-like intrinsic proteins are further involved in allowing Si entry into the cell. Therefore, on the basis of available published results and recent developments, we propose a model to explain how Si absorption alleviates stress in plants grown under saline conditions through the conjugated action of different aquaporins. PMID:28642767

  14. Selenium (Se) improves drought tolerance in crop plants--a myth or fact?

    PubMed

    Ahmad, Rashid; Waraich, Ejaz Ahmad; Nawaz, Fahim; Ashraf, Muhammad Y; Khalid, Muhammad

    2016-01-30

    Climate change has emerged as one of the most complex challenges of the 21st century and has become an area of interest in the past few decades. Many countries of the world have become extremely vulnerable to the impacts of climate change. The scarcity of water is a serious concern for food security of these countries and climate change has aggravated the risks of extreme events like drought. Oxidative stress, caused by a variety of active oxygen species formed under drought stress, damages many cellular constituents, such as carbohydrates, lipids, nucleic acids and proteins, which ultimately reduces plant growth, respiration and photosynthesis. Se has become an element of interest to many biologists owing to its physiological and toxicological importance. It plays a beneficial role in plants by enhancing growth, reducing damage caused by oxidative stress, enhancing chlorophyll content under light stress, stimulating senesce to produce antioxidants and improving plant tolerance to drought stress by regulating water status. Researchers have adopted different strategies to evaluate the role of selenium in plants under drought stress. Some of the relevant work available regarding the role of Se in alleviating adverse effect of drought stress is discussed in this paper. © 2015 Society of Chemical Industry.

  15. Improving intercropping: a synthesis of research in agronomy, plant physiology and ecology.

    PubMed

    Brooker, Rob W; Bennett, Alison E; Cong, Wen-Feng; Daniell, Tim J; George, Timothy S; Hallett, Paul D; Hawes, Cathy; Iannetta, Pietro P M; Jones, Hamlyn G; Karley, Alison J; Li, Long; McKenzie, Blair M; Pakeman, Robin J; Paterson, Eric; Schöb, Christian; Shen, Jianbo; Squire, Geoff; Watson, Christine A; Zhang, Chaochun; Zhang, Fusuo; Zhang, Junling; White, Philip J

    2015-04-01

    Intercropping is a farming practice involving two or more crop species, or genotypes, growing together and coexisting for a time. On the fringes of modern intensive agriculture, intercropping is important in many subsistence or low-input/resource-limited agricultural systems. By allowing genuine yield gains without increased inputs, or greater stability of yield with decreased inputs, intercropping could be one route to delivering ‘sustainable intensification’. We discuss how recent knowledge from agronomy, plant physiology and ecology can be combined with the aim of improving intercropping systems. Recent advances in agronomy and plant physiology include better understanding of the mechanisms of interactions between crop genotypes and species – for example, enhanced resource availability through niche complementarity. Ecological advances include better understanding of the context-dependency of interactions, the mechanisms behind disease and pest avoidance, the links between above- and below-ground systems, and the role of microtopographic variation in coexistence. This improved understanding can guide approaches for improving intercropping systems, including breeding crops for intercropping. Although such advances can help to improve intercropping systems, we suggest that other topics also need addressing. These include better assessment of the wider benefits of intercropping in terms of multiple ecosystem services, collaboration with agricultural engineering, and more effective interdisciplinary research.

  16. Battery available power prediction of hybrid electric vehicle based on improved Dynamic Matrix Control algorithms

    NASA Astrophysics Data System (ADS)

    Wang, Limei; Cheng, Yong; Zou, Ju

    2014-09-01

    The core technology to any hybrid engine vehicle (HEV) is the design of energy management strategy (EMS). To develop a reasonable EMS, it is necessary to monitor the state of capacity, state of health and instantaneous available power of battery packs. A new method that linearizes RC equivalent circuit model and predicts battery available power according to original Dynamic Matrix Control algorithm is proposed. To verify the validity of the new algorithm, a bench test with lithium-ion battery cell and a HEV test with lithium-ion battery packs are carried out. The bench test results indicate that a single RC block equivalent circuit model could be used to describe the dynamic and the steady state characteristics of a battery under testing conditions. However, lacking of long time constant of RC modules, there is a sample deviation in the open-circuit voltage identified and that measured. The HEV testing results show that the battery voltage predicted is in good agreement with that measured, the maximum difference is within 3.7%. Fixing the time constant to a numeric value, satisfactory results can still be achieved. After setting a battery discharge cut-off voltage, the instantaneous available power of the battery can be predicted.

  17. Improving Fatty Acid Availability for Bio-Hydrocarbon Production in Escherichia coli by Metabolic Engineering

    PubMed Central

    Lin, Fengming; Chen, Yu; Levine, Robert; Lee, Kilho; Yuan, Yingjin; Lin, Xiaoxia Nina

    2013-01-01

    Previous studies have demonstrated the feasibility of producing fatty-acid-derived hydrocarbons in Escherichia coli. However, product titers and yields remain low. In this work, we demonstrate new methods for improving fatty acid production by modifying central carbon metabolism and storing fatty acids in triacylglycerol. Based on suggestions from a computational model, we deleted seven genes involved in aerobic respiration, mixed-acid fermentation, and glyoxylate bypass (in the order of cyoA, nuoA, ndh, adhE, dld, pta, and iclR) to modify the central carbon metabolic/regulatory networks. These gene deletions led to increased total fatty acids, which were the highest in the mutants containing five or six gene knockouts. Additionally, when two key enzymes in the fatty acid biosynthesis pathway were over-expressed, we observed further increase in strain △cyoA△adhE△nuoA△ndh△pta△dld, leading to 202 mg/g dry cell weight of total fatty acids, ~250% of that in the wild-type strain. Meanwhile, we successfully introduced a triacylglycerol biosynthesis pathway into E. coli through heterologous expression of wax ester synthase/acyl-coenzyme:diacylglycerol acyltransferase (WS/DGAT) enzymes. The added pathway improved both the amount and fuel quality of the fatty acids. These new metabolic engineering strategies are providing promising directions for future investigation. PMID:24147139

  18. Optimization of the diffusive gradients in thin films (DGT) method for simultaneous assay of potassium and plant-available phosphorus in soils.

    PubMed

    Zhang, Yulin; Mason, Sean; McNeill, Ann; McLaughlin, Michael J

    2013-09-15

    Potassium (K) and phosphorus (P) are two important macronutrients for crops, and are usually applied to soils as granular fertilizer before seeding. Therefore, accurate soil tests prior to planting to predict crop response to fertilizers are important in optimizing crop yields. Traditional methods used for testing both available K and P in soils, which are based on chemical extraction procedures, are to be soil-type dependent, and the predictive relationships across a broad range of soils are generally poor. The diffusive gradients in thin films (DGT) technique, based on diffusion theory, is extensively used to measure the diffusive supply of trace elements, metals and some nutrients in soils and water. When DGT is used to assess plant-available P in soils, a good relationship is found between crop response to P fertilizer and concentrations of P in soil measured by DGT, and therefore the DGT method provides a more precise recommendation of P fertilizer requirements. Adaptation of the DGT method to measure plant-available K in soils has already been attempted [1], but limitations were reported due to the non-uniform size of the resin gel, decreased K binding rate of the gel at long deployment times and a limited ability to measure a wide range of K concentrations. To eliminate these problems, a new resin gel has been developed by combining Amberlite and ferrihydrite. This mixed Amberlite and ferrihydrite (MAF) gel has improved properties in terms of handling and even distribution of Amberlite in the gel. The elution efficiencies of the MAF gel for K and P were 90% and 96%, respectively. The diffusion coefficient of K through the diffusive gel was 1.30 × 10(-5)cm(2)s(-1) at 22 ± 1°C and was stable through time. Since ferrihydrite is already used in DGT P testing, the ability of the MAF gel to assess available P simultaneously was also assessed. The MAF gel performed the same as the traditional ferrihydrite gel for available P assessment in a wide variety of

  19. AN INDEX OF THE AVAILABLE MEDICINAL PLANTS, USED IN INDIAN SYSTEM OF MEDICINE FROM JAMMU AND KASHMIR STATE

    PubMed Central

    Srivastava, T. N.; Rajasekharan, S.; Badola, D. P.; Shah, D. C.

    1986-01-01

    The medicinal plants used in Indian system of medicine and its distribution in Jammu and Kashmir has been categorized systematically here. The paper deals with 246 medicinal plants and has to off-set an index which is not there so far. Out of 246 medicinal plants 12 plants are considered to be controversial. Substitutes, Adulterants of these plants which are being used in various parts of India were also recorded separately in this study. PMID:22557549

  20. Collect Data, Tell Stories: Utilizing Available Data to Improve Wound Product Selection, Reduce Costs, and Improve Outcomes.

    PubMed

    Mostow, Eliot; Montemayor, Jon D; Pittinger, Sean; Miller, Stephannie; Blasiole, Kimberly N; Fulton, Judith

    2014-08-01

    Objective: To develop a tool to assist in the evaluation of treatment options based on clinically relevant parameters, thus enabling clinicians to heal patients more efficiently. Approach: Outlined here is the prototypic model of a comprehensive analysis tool to compare products by category, accounting for product characteristics, effectiveness data from literature, costs, and patient needs or clinician preferences. Results: The tool is demonstrated with a venous leg ulcer example, and ideas for expanding the tool in the future are provided. Innovation: Although this is a simple model, the authors believe that it provides a valid and useful platform for comparing similar products of a given type using available information and reflecting real-world use to give a practical approach to clinical decision-making. Conclusion: Future funding for comprehensive, comparative effectiveness studies should provide clarity on which products to choose for specific applications. Meanwhile, tools like this can provide guidance, and can be modified to accommodate varying circumstances.

  1. Collect Data, Tell Stories: Utilizing Available Data to Improve Wound Product Selection, Reduce Costs, and Improve Outcomes

    PubMed Central

    Mostow, Eliot; Montemayor, Jon D.; Pittinger, Sean; Miller, Stephannie; Blasiole, Kimberly N.; Fulton, Judith

    2014-01-01

    Objective: To develop a tool to assist in the evaluation of treatment options based on clinically relevant parameters, thus enabling clinicians to heal patients more efficiently. Approach: Outlined here is the prototypic model of a comprehensive analysis tool to compare products by category, accounting for product characteristics, effectiveness data from literature, costs, and patient needs or clinician preferences. Results: The tool is demonstrated with a venous leg ulcer example, and ideas for expanding the tool in the future are provided. Innovation: Although this is a simple model, the authors believe that it provides a valid and useful platform for comparing similar products of a given type using available information and reflecting real-world use to give a practical approach to clinical decision-making. Conclusion: Future funding for comprehensive, comparative effectiveness studies should provide clarity on which products to choose for specific applications. Meanwhile, tools like this can provide guidance, and can be modified to accommodate varying circumstances. PMID:25126475

  2. Modelling the Impact of Climate Change on Soil Water Availability and Plant Community Shifts in the Colorado Plateau

    NASA Astrophysics Data System (ADS)

    Thomas, A.; Gill, R. A.

    2016-12-01

    Climate change with an accompanying decrease in soil moisture is expected to have a significant impact on the sensitive, water-limited ecosystems of America's southwestern deserts. Already, studies have documented shifts in the distributions of competing grasses and shrubs in this region, potentially altering ecosystem function. Of particular interest is the loss of desert grasses and the expansion of desert shrubs over the past three decades. The objective of this work is to use a process-based hydrological model to extrapolate site-level measurements to assess trends in soil moisture availability that may impact plant communities in the Colorado Plateau and surrounding regions. The model, SOILWAT, simulates the daily movement of water through plant and soil layers, incorporating precipitation, interception, evaporation, infiltration between soil layers, and absorption and transpiration by plants, as well as physical site characteristics. We applied SOILWAT to 50 sites that were stratified through the northern, central, and southern regions of Ephedra viridis. We focused on E. viridis because it has displaced desert grasses in plot-scale studies. The model was driven using spatially interpolated daily weather data from the PRISM climate model over a 34-year period. We found that across all years, average soil water content in the sandy soil of the region was higher in soil layers 40-60 cm deep than in the top 20 cm, and highest in the deepest layers down to 100 cm. The consistently higher margin of water in deeper layers may indicate the vulnerability of shallow-rooted grass to increasing evaporation and an advantage to deeply-rooted shrubs such as Ephedra.

  3. Bromeliad-living spiders improve host plant nutrition and growth.

    PubMed

    Romero, Gustavo Q; Mazzafera, Paulo; Vasconcellos-Neto, Joao; Trivelin, Paulo C O

    2006-04-01

    Although bromeliads are believed to obtain nutrients from debris deposited by animals in their rosettes, there is little evidence to support this assumption. Using stable isotope methods, we found that the Neotropical jumping spider Psecas chapoda (Salticidae), which lives strictly associated with the terrestrial bromeliad Bromelia balansae, contributed 18% of the total nitrogen of its host plant in a greenhouse experiment. In a one-year field experiment, plants with spiders produced leaves 15% longer than plants from which the spiders were excluded. This is the first study to show nutrient provisioning in a spider-plant system. Because several animal species live strictly associated with bromeliad rosettes, this type of facultative mutualism involving the Bromeliaceae may be more common than previously thought.

  4. Improved pose and affinity predictions using different protocols tailored on the basis of data availability

    NASA Astrophysics Data System (ADS)

    Prathipati, Philip; Nagao, Chioko; Ahmad, Shandar; Mizuguchi, Kenji

    2016-09-01

    The D3R 2015 grand drug design challenge provided a set of blinded challenges for evaluating the applicability of our protocols for pose and affinity prediction. In the present study, we report the application of two different strategies for the two D3R protein targets HSP90 and MAP4K4. HSP90 is a well-studied target system with numerous co-crystal structures and SAR data. Furthermore the D3R HSP90 test compounds showed high structural similarity to existing HSP90 inhibitors in BindingDB. Thus, we adopted an integrated docking and scoring approach involving a combination of both pharmacophoric and heavy atom similarity alignments, local minimization and quantitative structure activity relationships modeling, resulting in the reasonable prediction of pose [with the root mean square deviation (RMSD) values of 1.75 Å for mean pose 1, 1.417 Å for the mean best pose and 1.85 Å for the mean all poses] and affinity (ROC AUC = 0.702 at 7.5 pIC50 cut-off and R = 0.45 for 180 compounds). The second protein, MAP4K4, represents a novel system with limited SAR and co-crystal structure data and little structural similarity of the D3R MAP4K4 test compounds to known MAP4K4 ligands. For this system, we implemented an exhaustive pose and affinity prediction protocol involving docking and scoring using the PLANTS software which considers side chain flexibility together with protein-ligand fingerprints analysis assisting in pose prioritization. This protocol through fares poorly in pose prediction (with the RMSD values of 4.346 Å for mean pose 1, 4.69 Å for mean best pose and 4.75 Å for mean all poses) and produced reasonable affinity prediction (AUC = 0.728 at 7.5 pIC50 cut-off and R = 0.67 for 18 compounds, ranked 1st among 80 submissions).

  5. Carbon cost of plant nitrogen acquisition: global carbon cycle impact from an improved plant nitrogen cycle in the Community Land Model.

    PubMed

    Shi, Mingjie; Fisher, Joshua B; Brzostek, Edward R; Phillips, Richard P

    2016-03-01

    Plants typically expend a significant portion of their available carbon (C) on nutrient acquisition - C that could otherwise support growth. However, given that most global terrestrial biosphere models (TBMs) do not include the C cost of nutrient acquisition, these models fail to represent current and future constraints to the land C sink. Here, we integrated a plant productivity-optimized nutrient acquisition model - the Fixation and Uptake of Nitrogen Model - into one of the most widely used TBMs, the Community Land Model. Global plant nitrogen (N) uptake is dynamically simulated in the coupled model based on the C costs of N acquisition from mycorrhizal roots, nonmycorrhizal roots, N-fixing microbes, and retranslocation (from senescing leaves). We find that at the global scale, plants spend 2.4 Pg C yr(-1) to acquire 1.0 Pg N yr(-1) , and that the C cost of N acquisition leads to a downregulation of global net primary production (NPP) by 13%. Mycorrhizal uptake represented the dominant pathway by which N is acquired, accounting for ~66% of the N uptake by plants. Notably, roots associating with arbuscular mycorrhizal (AM) fungi - generally considered for their role in phosphorus (P) acquisition - are estimated to be the primary source of global plant N uptake owing to the dominance of AM-associated plants in mid- and low-latitude biomes. Overall, our coupled model improves the representations of NPP downregulation globally and generates spatially explicit patterns of belowground C allocation, soil N uptake, and N retranslocation at the global scale. Such model improvements are critical for predicting how plant responses to altered N availability (owing to N deposition, rising atmospheric CO2 , and warming temperatures) may impact the land C sink.

  6. Cool perch availability improves the performance and welfare status of broiler chickens in hot weather.

    PubMed

    Zhao, J P; Jiao, H C; Jiang, Y B; Song, Z G; Wang, X J; Lin, H

    2012-08-01

    A study was conducted to determine whether water-cooled perches would be preferred by commercial broilers exposed to a hot ambient environment, and subsequently, whether utilization of these perches would improve performance and the well-being of birds, beyond those provided by normal perches. Four hundred and thirty-two 14-d-old male chickens from a commercial fast-growing strain (Arbor Acres) were housed in the following conditions: 1) cool perches, 2) normal perches, and 3) control pens with no perches. The results showed that there was greater use of cool perches than normal perches for broiler chickens during summer (F1, 4=125, P=0.0004). Cool perches increased BW gain (F2, 6=5.44, P=0.0449) and breast (F2, 24=3.31, P=0.0539) and thigh muscle yields (F2, 24=6.29, P=0.0063), while decreasing abdominal fat deposition (F2, 24=7.57, P=0.0028), cooking loss (pectoralis major, F2, 24=3.30, P=0.0542; biceps femoris, F2, 24=3.42, P=0.0493), percentage of panting birds (F2, 6=102, P<0.0001), and scores of footpad (F2, 6=122, P<0.0001) and hock (F2, 6=68.2, P<0.0001) burn, and abdominal plumage condition (F2, 6=52.0, P=0.0002), particularly toward the end of the rearing period. In contrast, normal perches hardly affected growth performance, carcass composition, meat quality and behavioral patterns, and appeared to worsen the welfare status, including footpad and hock burns and abdominal plumage condition, due to a lower occupancy rate. Cool perches offer a thermoregulatory and performance advantage to broilers exposed to a hot environment and appear to be a management strategy for improving the production and well-being of commercial broilers.

  7. Resveratrol biosynthesis: plant metabolic engineering for nutritional improvement of food.

    PubMed

    Giovinazzo, Giovanna; Ingrosso, Ilaria; Paradiso, Annalisa; De Gara, Laura; Santino, Angelo

    2012-09-01

    The plant polyphenol trans-resveratrol (3, 5, 4'-trihydroxystilbene) mainly found in grape, peanut and other few plants, displays a wide range of biological effects. Numerous in vitro studies have described various biological effects of resveratrol. In order to provide more information regarding absorption, metabolism, and bioavailability of resveratrol, various research approaches have been performed, including in vitro, ex vivo, and in vivo models. In recent years, the induction of resveratrol synthesis in plants which normally do not accumulate such polyphenol, has been successfully achieved by molecular engineering. In this context, the ectopic production of resveratrol has been reported to have positive effects both on plant resistance to biotic stress and the enhancement of the nutritional value of several widely consumed fruits and vegetables. The metabolic engineering of plants offers the opportunity to change the content of specific phytonutrients in plant - derived foods. This review focuses on the latest findings regarding on resveratrol bioproduction and its effects on the prevention of the major pathological conditions in man.

  8. Impacts of rapeseed dregs on Cd availability in contaminated acid soil and Cd translocation and accumulation in rice plants.

    PubMed

    Yang, Wen-Tao; Gu, Jiao-Feng; Zou, Jia-Ling; Zhou, Hang; Zeng, Qing-Ru; Liao, Bo-Han

    2016-10-01

    The objective of the present study was to investigate the effects of rapeseed dregs (RSD, a commonly organic fertilizer in rural China) at application rates of 0, 0.75, 1.5, and 3.0 % on Cd availability in soil and its accumulation in rice plants (Oryza sativa L., Xiangwanxian 12(#), and Weiyou 46(#)) by means of a pot experiment. The results showed that application of RSD resulted in a sharp decrease in the soil TCLP-extractable Cd content. However, the soil TCLP-extractable Cd content in amended soil gradually increased during the rice growing period. Application of RSD significantly increased Cd transport from root to shoot and the amount of Cd accumulated in the aerial part. RSD was an effective organic additive for increasing rice grain yield, but total Cd content in rice grain was also increased. At an application rate of 1.5-3.0 % RSD, the total Cd content in Weiyou 46(#) brown rice was 0.27-0.31 mg kg(-1), which exceeded the standard safe limit (0.2 mg kg(-1)) and was also higher than that of Xiangwanxian 12(#) (0.04-0.14 mg kg(-1)). Therefore, Weiyou 46(#) had a higher dietary risk than Xiangwanxian 12(#) with RSD application. We do not recommend planting Weiyou 46(#) and applying more than 0.75 % RSD in Cd-contaminated paddy fields.

  9. Advances in RNA interference technology and its impact on nutritional improvement, disease and insect control in plants.

    PubMed

    Katoch, Rajan; Thakur, Neelam

    2013-03-01

    This review highlights the advances in the knowledge of RNA interference (RNAi) and discusses recent progress on the functionality of different components RNAi machinery operating in the organisms. The silencing of genes by RNA interference has become the technology of choice for investigation of gene functions in different organisms. The refinement in the knowledge of the endogenous RNAi pathways in plants along with the development of new strategies and applications for the improvement of nutritional value of important agricultural crops through suppression of genes in different plants have opened new vistas for nutritional security. The improvement in the nutritional status of the plants and reduction in the level of toxins or antinutrients was desired for long, but the available technology was not completely successful in achieving the tissue specific regulation of some genes. In the recent years, a number of economically important crop plants have been tested successfully for improving plant nutritional value through metabolic engineering using RNAi. The implications of this technology for crop improvement programs, including nutritional enrichment, reduction of antinutrients, disease, and insect control have been successfully tested in variety of crops with commercial considerations. The enhancement of the nutraceutical traits for the desired health benefits in common crop plants through manipulation of gene expression has been elaborated in this article. The tremendous potential with RNAi technology is expected to revolutionize the modern agriculture for meeting the growing challenges is discussed.

  10. Guide for prioritizing power plant productivity improvement projects: modification and simplification of the DOE/MRI methodology

    SciTech Connect

    Not Available

    1981-03-01

    In recent years, the subject of public utility power plant productivity and reliability has received significant attention from both federal and state agencies and from within the utilities. One study was a FEA-sponsored program that had as its purpose the development of improved techniques for assessing cause of power plant unavailability. The results of this study have become widely known as the DOE/MRI methodology for calculating increased power plant equivalent availability resulting from instituting improvement projects. To further the development of the DOE/MRI methodology for assessing and quantifying the effect of improvement projects, the DOE initiated studies with two states to demonstrate the methodology in operating plants. These studies were focused on applying the methodology to specific power plants (fossil-fueled and nuclear) and on identifying any difficulties in using the method. In the course of these investigations, several problems were uncovered. Various recommendations were made for both eliminating the identified deficiencies in the methodology and for simplifying several of the calculations needed to evaluate proposed plant improvements. The information provided here describes four major modifications to the DOE/MRI methodology which eliminate previously uncovered deficiencies and simplify calculational methods.

  11. [Assessment on the availability of nitrogen fertilization in improving carbon sequestration potential of China's cropland soil].

    PubMed

    Lu, Fei; Wang, Xiao-Ke; Han, Bing; Ouyang, Zhi-Yun; Duan, Xiao-Nan; Zheng, Hua

    2008-10-01

    With reference to the situation of nitrogen fertilization in 2003 and the recommendations from agricultural experts on fertilization to different crops, two scenarios, namely, 'current situation' and 'fertilization as recommended', were set for estimating the current and potential carbon sequestration of China's cropland soil under nitrogen fertilization. After collecting and analyzing the typical data from the long-term agricultural experiment stations all over China, and based on the recent studies of soil organic matter and nutrient dynamics, we plotted China into four agricultural regions, and estimated the carbon sequestration rate and potential of cropland soil under the two scenarios in each province of China. Meanwhile, with the data concerning fossil fuel consumption for fertilizer production and nitrogen fertilization, the greenhouse gas leakage caused by nitrogen fertilizer production and application was estimated with the help of the parameters given by domestic studies and IPCC. We further proposed that the available carbon sequestration potential of cropland soil could be taken as the criterion of the validity and availability of carbon sequestration measures. The results showed that the application of synthetic nitrogen fertilizer could bring about a carbon sequestration potential of 21.9 Tg C x a(-1) in current situation, and 30.2 Tg C x a(-1) with fertilization as recommended. However, under the two scenarios, the greenhouse gas leakage caused by fertilizer production and application would reach 72.9 Tg C x a(-1) and 91.4 Tg C x a(-1), and thus, the actual available carbon sequestration potential would be -51.0 Tg C x a(-1) and -61.1 Tg C x a(-1), respectively. The situation was even worse under the 'fertilization as recommended' scenario, because the increase in the amount of nitrogen fertilization would lead to 10. 1 Tg C x a(-1) or more net greenhouse gas emission. All these results indicated that the application of synthetic nitrogen fertilizer

  12. Effects of sewage sludge on pH and plant availability of metals in oxidising sulphide mine tailings.

    PubMed

    Forsberg, Lovisa Stjernman; Ledin, Stig

    2006-04-01

    A field study was conducted adjacent to the tailings deposit of the Aitik copper mine in the north of Sweden to investigate the effects of sewage sludge on pH and plant availability of Al, Mn, Cu, Zn, Ni, Pb, As, Cr and Cd in the oxidising sulphide tailings. One treatment was supplied with sewage sludge, while the control received NPK-fertiliser. The tailings samples were collected at the beginning and the end of the growing season and extracted by NH(4)NO(3), NH(4)Ac-EDTA and HNO(3). Plant tissue concentrations of the elements were determined in the above-ground parts of barley (Hordeum vulgare) and red fescue (Festuca rubra). The application of sewage sludge resulted in higher crop yields compared to the control, although the buffering capacity and the metal immobilising effect of the sludge were limited. The pH decreased from 6.6 to 4.3 in the control and from 6.4 to 4.8 in the sludge-treated tailings during the growing season, probably due to sulphide oxidation in the tailings. This resulted in increased levels of soluble elements in all treatments studied. Application of sewage sludge resulted in elevated levels of soluble Zn and lower values of soluble As and Cd in the unaltered tailings but increased levels of specifically adsorbed Cu, Ni and As in the oxidised tailings. This was partly reflected in the plants, as the application of sewage sludge resulted in 67 mg Zn kg(-1) in barley grains and 60 mg Zn kg(-1) in red fescue shoots, both values twice as high as the corresponding values in the control, but lower As contents in both straw (0.3 mg kg(-1)) and grain (0.06 mg kg(-1)) of barley compared to the control (0.6 and 0.2 mg kg(-1), respectively). In addition, red fescue grown in sludge-treated plots contained significantly higher levels of Al, Cu, Pb, As and Cr compared to the control. The levels of several metals in barley and red fescue grown in both treatments exceeded background values found in the literature. The Cu content in barley straw exceeded

  13. Reduced by-product formation and modified oxygen availability improve itaconic acid production in Aspergillus niger.

    PubMed

    Li, An; Pfelzer, Nina; Zuijderwijk, Robbert; Brickwedde, Anja; van Zeijl, Cora; Punt, Peter

    2013-05-01

    Aspergillus niger has an extraordinary potential to produce organic acids as proven by its application in industrial citric acid production. Previously, it was shown that expression of the cis-aconitate decarboxylase gene (cadA) from Aspergillus terreus converted A. niger into an itaconic acid producer (Li et al., Fungal Genet Bio 48: 602-611, 2011). After some initial steps in production optimization in the previous research (Li et al., BMC biotechnol 12: 57, 2012), this research aims at modifying host strains and fermentation conditions to further improve itaconic acid production. Expression of two previously identified A. terreus genes encoding putative organic acid transporters (mttA, mfsA) increased itaconic acid production in an A. niger cis-aconitate decarboxylase expressing strain. Surprisingly, the production did not increase further when both transporters were expressed together. Meanwhile, oxalic acid was accumulated as a by-product in the culture of mfsA transformants. In order to further increase itaconic acid production and eliminate by-product formation, the non-acidifying strain D15#26 and the oxaloacetate acetylhydrolase (oahA) deletion strain AB 1.13 ∆oahA #76 have been analyzed for itaconic acid production. Whereas cadA expression in AB 1.13 ∆oahA #76 resulted in higher itaconic acid production than strain CAD 10.1, this was not the case in strain D15#26. As expected, oxalic acid production was eliminated in both strains. In a further attempt to increase itaconic acid levels, an improved basal citric acid-producing strain, N201, was used for cadA expression. A selected transformant (N201CAD) produced more itaconic acid than strain CAD 10.1, derived from A. niger strain AB1.13. Subsequently, we have focused on the influence of dissolved oxygen (D.O.) on itaconic acid production. Interestingly, reduced D.O. levels (10-25 %) increased itaconic acid production using strain N201 CAD. Similar results were obtained in strain AB 1.13 CAD + HBD2

  14. Effects of Sediment Nitrogen Availability and Plant Density on Interactions Between the Growth of Hydrilla Verticillata and Potamogeton Americanus. Aquatic Plant Control Research Program.

    DTIC Science & Technology

    1991-12-01

    fractions. Suppression coefficients for each species were calculated to summarize competitive effects in mixtures relative to grow*.h of plants alone...11 4 Discussion Responses to Density A long-standing criticism of plant competition experiments has been the use of a single initial plant density... competitive superiority may be more sensitive than others to initial plant density (for review, see Rousch et al. 1989). However, initial plant density

  15. Lab to Farm: Applying Research on Plant Genetics and Genomics to Crop Improvement

    PubMed Central

    Ronald, Pamela C.

    2014-01-01

    Over the last 300 years, plant science research has provided important knowledge and technologies for advancing the sustainability of agriculture. In this Essay, I describe how basic research advances have been translated into crop improvement, explore some lessons learned, and discuss the potential for current and future contribution of plant genetic improvement technologies to continue to enhance food security and agricultural sustainability. PMID:24915201

  16. Mathematical modeling and fuzzy availability analysis for serial processes in the crystallization system of a sugar plant

    NASA Astrophysics Data System (ADS)

    Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram

    2016-08-01

    The binary states, i.e., success or failed state assumptions used in conventional reliability are inappropriate for reliability analysis of complex industrial systems due to lack of sufficient probabilistic information. For large complex systems, the uncertainty of each individual parameter enhances the uncertainty of the system reliability. In this paper, the concept of fuzzy reliability has been used for reliability analysis of the system, and the effect of coverage factor, failure and repair rates of subsystems on fuzzy availability for fault-tolerant crystallization system of sugar plant is analyzed. Mathematical modeling of the system is carried out using the mnemonic rule to derive Chapman-Kolmogorov differential equations. These governing differential equations are solved with Runge-Kutta fourth-order method.

  17. Generic requirements specification for qualifying a commercially available PLC for safety-related applications in nuclear power plants. Final report

    SciTech Connect

    Ostenso, A.; May, R.

    1996-12-01

    This is a specification for qualifying a commercially available PLC for application to safety systems in nuclear power plants. The specifications are suitable for evaluating a particular PLC product line as a platform for safety-related applications, establishing a suitable qualification test program, and confirming that the manufacturer has a quality assurance program that is adequate for safety-related applications or is sufficiently complete that, with a reasonable set of compensatory actions, it can be brought into conformance. The specification includes requirements for: (1) quality assurance measures applied to the qualification activities, (2) documentation to support the qualification, and (3) documentation to provide the information needed for applying the qualified PLC platform to a specific application. The specifications are designed to encompass a broad range of safety applications; however, qualifying a particular platform for a different range of applications can be accomplished by appropriate adjustments to the requirements.

  18. Mathematical modeling and fuzzy availability analysis for serial processes in the crystallization system of a sugar plant

    NASA Astrophysics Data System (ADS)

    Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram

    2017-08-01

    The binary states, i.e., success or failed state assumptions used in conventional reliability are inappropriate for reliability analysis of complex industrial systems due to lack of sufficient probabilistic information. For large complex systems, the uncertainty of each individual parameter enhances the uncertainty of the system reliability. In this paper, the concept of fuzzy reliability has been used for reliability analysis of the system, and the effect of coverage factor, failure and repair rates of subsystems on fuzzy availability for fault-tolerant crystallization system of sugar plant is analyzed. Mathematical modeling of the system is carried out using the mnemonic rule to derive Chapman-Kolmogorov differential equations. These governing differential equations are solved with Runge-Kutta fourth-order method.

  19. Improved enzymatic method to measure processing effects and starch availability in sorghum grain.

    PubMed

    Xiong, Y; Bartle, S J; Preston, R L

    1990-11-01

    A modified enzymatic method to measure processing effects and starch availability in steam-flaked sorghum grain (SFSG) was developed. To establish the method, experiments were conducted to determine the required enzyme concentration, color reagents, precipitants, sample particle size, shaking frequency and buffer pH. Glucose release at different incubation times (0 to 48 h) from uncooked (UNC) or fully cooked (CK, 100% gelatinized) ground sorghum grain, a 50:50 mixture of UNC and CK (C50) and SFSG was determined. Glucose release from UNC, CK and SFSG was expressed as one-component equations with rate constant k and r2 of .119 and .98, 1.781 and .98, and .368 and .99, respectively; C50 was characterized by having two starch components, one with a fast rate constant, 2.624/h, and one with a slow rate constant, .066/h (R2 = .99). Different degrees of gelatinization were obtained by mixing different proportions of CK and UNC. Glucose release from these samples was highly correlated with starch gelatinization (r2 = .99). By adjusting the tension between mill rollers, five SFSG samples with bulk densities ranging from 476 to 283 g/liter (37 to 22 lb/bu) were produced; respective roller mill electrical load ranged from 21 to 51.5 amps. Enzymatic determination of glucose release resulted in values of 422, 512, 588, 618 and 678 mg/g, which were more closely related to bulk density than birefringence measurements. The modified method for starch availability determination was found to be relatively simple, fast and sensitive, and is recommended.

  20. Challenges and strategies to improve the availability and geographic accessibility of physicians in Portugal.

    PubMed

    de Oliveira, Ana Paula Cavalcante; Dussault, Gilles; Craveiro, Isabel

    2017-03-23

    Shortages of physicians in remote, rural and other underserved areas and lack of general practitioners limit access to health services. The aims of this article are to identify the challenges faced by policy and decision-makers in Portugal to guarantee the availability and geographic accessibility to physicians in the National Health Service and to describe and analyse their causes, the strategies to tackle them and their results. We also raise the issue of whether research evidence was used or not in the process of policy development. We analysed policy and technical documents, peer-reviewed papers and newspaper articles from 1995 to 2015 through a structured search of government websites, Portuguese online newspapers and PubMed and Virtual Health Library (Biblioteca Virtual em Saúde (BVS)) databases; key informants were consulted to validate and complement the documentary search. The challenges faced by decision-makers to ensure access to physicians were identified as a forecasted shortage of physicians, geographical imbalances and maldistribution of physicians by level of care. To date, no human resources for health policy has been formulated, in spite of most documents reviewed stating that it is needed. On the other hand, various isolated and ad hoc strategies have been adopted, such as incentives to choose family health as a specialty or to work in an underserved region and recruitment of foreign physicians through bilateral agreements. Health workforce research in Portugal is scarce, and therefore, policy decisions regarding the availability and accessibility of physicians are not based on evidence. The policy interventions described in this paper should be evaluated, which would be a good starting point to inform health workforce policy development.

  1. Milk-based phospholipids increase morning cortisol availability and improve memory in chronically stressed men.

    PubMed

    Schubert, Melanie; Contreras, Carina; Franz, Nadin; Hellhammer, Juliane

    2011-06-01

    Phospholipids (PLs) have been shown to dampen the activity and reactivity of the hypothalamic-pituitary-adrenal axis (HPAA). To further investigate stress protective effects of PL, 75 chronically stressed men aged 30 to 51 years were enrolled in a randomized and placebo-controlled trial. The subjects received a bovine milk drink with either 0.5% PL, 1% PL, or a placebo for 42 days to test the hypothesis that supplementation with specific phospholipids would normalize the cortisol response of the HPAA. For determining HPAA activity, the cortisol awakening response was studied before and after treatment. In addition, participants were exposed to an acute stressor, the Trier Social Stress Test, to assess treatment effects on stress reactivity and stress-related memory impairment. After receiving PL-enriched milk, both PL groups showed a delayed decline from peak levels in morning salivary cortisol, suggesting a prolonged availability of free cortisol. Treatment with 0.5% PL additionally resulted in a stronger increase of cortisol after awakening, whereas no such differences could be observed in the 1% PL group and the placebo group, respectively. The acute stress response did not significantly differ among placebo and PL groups. An exploratory data analysis further revealed that elderly participants receiving the higher PL dosage had a significant better memory performance after the Trier Social Stress Test as compared with elderly participants from the placebo and low-PL dosage group; no such difference was observed at baseline. Our results suggest that PL may increase the availability of cortisol in chronically stressed men and may attenuate stress-induced memory impairments. Results of the present study are discussed within the context of previous research and current state of knowledge. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Improving the turbine district heating installations of single-circuit nuclear power plants

    NASA Astrophysics Data System (ADS)

    Kondurov, E. P.; Kruglikov, P. A.; Smolkin, Yu. V.

    2015-10-01

    Ways for improving the turbine district heating installations of single-circuit nuclear power plants are considered as a possible approach to improving the nuclear power plant energy efficiency. The results of thermal tests carried out at one of single-circuit NPPs in Russia with a view to reveal the possibilities of improving the existing heat-transfer equipment of the turbine district heating installation without making significant investments in it were taken as a basis for the analysis. The tests have shown that there is certain energy saving potential in some individual units and elements in the turbine district heating installation's process circuit. A significant amount of thermal energy can be obtained only by decreasing the intermediate circuit temperature at the inlet to the heater of the first district-heating extraction. The taking of this measure will also lead to an additional amount of generated electricity because during operation with the partially loaded first heater, the necessary amount of heat has to be obtained from the peaking heater by reducing live steam. An additional amount of thermal energy can also be obtained by eliminating leaks through the bypass control valves. The possibility of achieving smaller consumption of electric energy for power plant auxiliaries by taking measures on reducing the available head in the intermediate circuit installation's pump unit is demonstrated. Partial cutting of pump impellers and dismantling of control valves are regarded to be the most efficient methods. The latter is attributed to qualitative control of the turbine district heating installation's thermal load. Adjustment of the noncondensable gas removal system will make it possible to improve the performance of the turbine district heating installation's heat-transfer equipment owing to bringing the heat-transfer coefficients in the heaters to the design level. The obtained results can be used for estimating the energy saving potential at other

  3. Impact of labile and recalcitrant carbon treatments on available nitrogen and plant communities in a semiarid ecosystem.

    PubMed

    Burke, I C; Bontti, E E; Barrett, J E; Lowe, P N; Lauenroth, W K; Riggle, R

    2013-04-01

    In a 10-year study, we assessed the influence of five carbon (C) treatments on the labile C and nitrogen (N) pools of historically N-enriched plots on the Shortgrass Steppe Long Term Ecological Research site located in northeastern Colorado. For eight years, we applied sawdust, sugar, industrial lignin, sawdust + sugar, and lignin + sugar to plots that had received N and water additions in the early 1970s. Previous work showed that past water and N additions altered plant species composition and enhanced rates of nutrient cycling; these effects were still apparent 25 years later. We hypothesized that labile C amendments would stimulate microbial activity and suppress rates of N mineralization, whereas complex forms of carbon (sawdust and lignin) could enhance humification and lead to longer-term reductions in N availability. Results indicated that, of the five carbon treatments, sugar, sawdust, and sawdust + sugar suppressed N availability, with sawdust + sugar being the most effective treatment to reduce N availability. The year after treatments stopped, N availability remained less in the sawdust + sugar treatment plots than in the high-N control plots. Three years after treatments ended, reductions in N availability were smaller (40-60%). Our results suggest that highly labile forms of carbon generate strong short-term N sinks, but these effects dissipate within one year of application, and that more recalcitrant forms reduce N longer. Sawdust + sugar was the most effective treatment to decrease exotic species canopy cover and increase native species density over the long term. Labile carbon had neither short- nor long-term effects on exotic species. Even though the organic amendments did not contribute to recovery of the dominant native species Bouteloua gracilis, they were effective in increasing another native species, Carex eleocharis. These results indicate that organic amendments may be a useful tool for restoring some native species in the shortgrass

  4. Securing endotracheal tubes: does NeoBar availability improve tube position?

    PubMed

    Brinsmead, Tammy Lee; Davies, Mark William

    2010-05-01

    To assess if neonatal endotracheal tube (ETT) position improved with introduction of the NeoBar. This retrospective study compared two cohorts of intubated neonates and their x-rays. During the first 2-month study period, ETTs were secured with tape only--the 'Tape-only' period; during the second study period, they were secured with a NeoBar (or tape if the NeoBar was unsuitable)--the 'NeoBar' period. ETT tip position was assessed subjectively as very high, high, OK, low, or very low; and objectively by vertebral body position and the ETT-tip-to-T1 distance. During the Tape-only period, 59 babies had 275 x-rays with an ETT visible. During the NeoBar period, 67 babies had 331 x-rays with an ETT visible. There were 160 (58.2%) and 193 (58.3%) assessed as OK during the Tape-only and NeoBar periods, respectively (Fisher's Exact Test, P= 1.0). There were more very high tubes during the NeoBar period, and more low and very low tubes during the Tape-only period (Chi-squared test, P= 0.011). A similar trend was observed with the distribution of the ETT-tip-to-T1 distance (difference not statistically significant, Mann-Whitney test, P= 0.079). During both time periods, less than two-thirds of ETTs were located in an acceptable position. For ETTs in unacceptable positions, there were more tubes in the higher positions during the NeoBar period, and more tubes in the lower positions during the Tape-only period. Further investigation is necessary to clarify if the differences in ETT position on x-ray correlate with relevant clinical outcomes.

  5. Acceleration in USA Sea-Level? New Insights Now Available Using Improved Analytical Tools and Methods

    NASA Astrophysics Data System (ADS)

    Watson, P. J.

    2016-12-01

    The detection of acceleration in mean sea-level around the data rich margins of the USA has been a keen endeavour of sea-level researchers post the seminal work of Bruce Douglas in 1992. Over the past decade, such investigations have taken on greater prominence given mean sea-level remains a key proxy by which to measure a changing climate system. The physics-based climate projection models are forecasting that the current global average rate of mean sea-level rise (≈ 3mm/year) might climb to rates in the range of 10-20 mm/year by 2100. Most research in this area has centred on reconciling current rates of rise with the significant accelerations required to meet the forecast projections of climate models. Various studies conducted over the past decade have provided inconsistent results which in part are due to both the small kinematic properties of the mean sea level signal evident in historical time series data and the limited analytical techniques applied to date to measure these phenomena. The analysis presented is based on a recently developed analytical package titled `msltrend', designed to augment climate change research by significantly enhancing estimates of trend, real-time velocity and acceleration in the relative mean sea-level signal derived from long annual average ocean water level time series. Key findings are that at the 95% confidence level, there is no consistent or substantial evidence (yet) that recent rates of rise are higher or abnormal in the context of the network of lengthy historical records available for the USA, nor is there any evidence that geocentric rates of rise are above the global average. The analysis also points to clearer spatial and temporal patterns in measured mean sea level around mainland USA than previously available. It is likely a further 20 years of data will distinguish whether recent increases east of Galveston and along the east coast are evidence of the onset of climate change induced acceleration.

  6. ERC product improvement activities for direct fuel cell power plants

    SciTech Connect

    Maru, H.C.; Farooque, M.; Bentley, C.

    1995-12-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  7. ERC product improvement activities for direct fuel cell power plants

    SciTech Connect

    Bentley, C.; Carlson, G.; Doyon, J.

    1995-08-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  8. Using wheel availability to shape running behavior of the rat towards improved behavioral and neurobiological outcomes.

    PubMed

    Basso, Julia C; Morrell, Joan I

    2017-10-01

    Though voluntary wheel running (VWR) has been used extensively to induce changes in both behavior and biology, little attention has been given to the way in which different variables influence VWR. This lack of understanding has led to an inability to utilize this behavior to its full potential, possibly blunting its effects on the endpoints of interest. We tested how running experience, sex, gonadal hormones, and wheel apparatus influence VWR in a range of wheel access "doses". VWR increases over several weeks, with females eventually running 1.5 times farther and faster than males. Limiting wheel access can be used as a tool to motivate subjects to run but restricts maximal running speeds attained by the rodents. Additionally, circulating gonadal hormones regulate wheel running behavior, but are not the sole basis of sex differences in running. Limitations from previous studies include the predominate use of males, emphasis on distance run, variable amounts of wheel availability, variable light-dark cycles, and possible food and/or water deprivation. We designed a comprehensive set of experiments to address these inconsistencies, providing data regarding the "microfeatures" of running, including distance run, time spent running, running rate, bouting behavior, and daily running patterns. By systematically altering wheel access, VWR behavior can be finely tuned - a feature that we hypothesize is due to its positive incentive salience. We demonstrate how to maximize VWR, which will allow investigators to optimize exercise-induced changes in their behavioral and/or biological endpoints of interest. Published by Elsevier B.V.

  9. Leveraging Cloud Computing to Improve Storage Durability, Availability, and Cost for MER Maestro

    NASA Technical Reports Server (NTRS)

    Chang, George W.; Powell, Mark W.; Callas, John L.; Torres, Recaredo J.; Shams, Khawaja S.

    2012-01-01

    The Maestro for MER (Mars Exploration Rover) software is the premiere operation and activity planning software for the Mars rovers, and it is required to deliver all of the processed image products to scientists on demand. These data span multiple storage arrays sized at 2 TB, and a backup scheme ensures data is not lost. In a catastrophe, these data would currently recover at 20 GB/hour, taking several days for a restoration. A seamless solution provides access to highly durable, highly available, scalable, and cost-effective storage capabilities. This approach also employs a novel technique that enables storage of the majority of data on the cloud and some data locally. This feature is used to store the most recent data locally in order to guarantee utmost reliability in case of an outage or disconnect from the Internet. This also obviates any changes to the software that generates the most recent data set as it still has the same interface to the file system as it did before updates

  10. Improving a commercially available heterodyne laser interferometer to sub-nm uncertainty

    NASA Astrophysics Data System (ADS)

    Haitjema, Han; Cosijns, Suzanne J. A. G.; Roset, N. J. J.; Jansen, Maarten J.

    2003-11-01

    Laser interferometer systems are known for their high resolution, and especially for their high range/resolution ratio. In dimensional metrology laboratories, laser interferometers are popular workhorses for the calibration of displacements. The uncertainty is usually limited to about 10 nm due to polarization- and frequency mixing. For demanding applications however nanometer uncertainty is desired. We adapted a commercially available heterodyne laser interferometer by feeding the measurement signal into a fast lock-in amplifier and use the laser interferometer reference signal as a reference. By measuring both the in-phase and quadrature component an uncorrected phase can be directly measured. By recording both components while the phase changes between 0 and 2π a typical ellipse is recorded from which the first and second harmonics of periodic deviations can be derived. These can be corrected independent of their origin. Measurements show that this method can reduce severe non-linearities (40 nm top-bottom) to a standard deviation of about 0.02 nm. Also, optical set-ups can be analysed to predict the non-linearities when a non-compensated standard interferometer is used.

  11. 76 FR 37769 - Bayer CropScience LP; Availability of Petition, Plant Pest Risk Assessment, and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant... into the environment) of organisms and products altered or produced through genetic engineering that...

  12. 78 FR 13312 - Pioneer Hi-Bred International, Inc.; Availability of Petition, Plant Pest Risk Assessment, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... and products altered or produced through genetic engineering that are plant pests or that there is... 7 CFR part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,'' regulate, among other...

  13. 77 FR 41358 - Bayer CropScience LP; Availability of Petition, Plant Pest Risk Assessment, and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... organisms and products altered or produced through genetic engineering that are plant pests or that there is... 7 CFR part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering ] Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,'' regulate, among...

  14. 76 FR 80872 - Dow AgroScience LLC; Availability of Petition, Plant Pest Risk Assessment, and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ... Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe..., or release into the environment) of organisms and products altered or produced through genetic engineering that are plant pests or that there is reason to believe are plant pests. Such genetically...

  15. Root growth and hydraulic conductivity of southern pine seedlings in response to soil temperature and water availability after planting

    Treesearch

    Mary Anne Sword Sayer; John C. Brissette; James P. Barnett

    2005-01-01

    Comparison of the root system growth and water transport of southern pine species after planting in different root-zone environments is needed to guide decisions regarding when, and what species to plant. Evaluation of how seed source affects root system responses to soil conditions will allow seed sources to be matched to planting conditions. The root growth and...

  16. Improvement of oral availability of ginseng fruit saponins by a proliposome delivery system containing sodium deoxycholate

    PubMed Central

    Hao, Fei; He, Yanxi; Sun, Yating; Zheng, Bin; Liu, Yan; Wang, Xinmei; Zhang, Yongkai; Lee, Robert J.; Teng, Lirong; Xie, Jing

    2015-01-01

    Ginseng fruit saponins (GFS) extracted from the ginseng fruit are the bioactive triterpenoid saponin components. The aim of the present study was to develop a drug delivery system called proliposome using sodium deoxycholate (NaDC) as a bile salt to improve the oral bioavailability of GFS in rats. The liposomes of GFS were prepared by a conventional ethanol injection and formed the solid proliposomes (P-GFS) using spray drying method on mannitol carriers. The formulation of P-GFS was optimized using the response surface methodology. The physicochemical properties of liposome suspensions including encapsulation efficiency, in vitro drug release studies, particle size of the reconstituted liposome were tested. The solid state characterization studies using the method of Field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) and Differential scanning colorimetric (DSC) were tested to study the molecular state of P-GFS and to indicate the interactions among the formulation ingredients. In vitro studies showed a delayed release of ginsenoside Re (GRe). In vivo studies were carried out in rats. The concentrations of GRe in plasma of rats and its pharmacokinetic behaviors after oral administration of GFS, Zhenyuan tablets (commercial dosage form of GFS) and P-GFS were studied using ultra performance liquid chromatography tandem mass spectrometry. It was founded that the GRe concentration time curves of GFS, Zhenyuan tablets and P-GFS were much more different in rats. Pharmacokinetic behaviors of P-GFS showed a second absorption peak on the concentration time curve. The pharmacokinetic parameters of GFS, Zhenyuan tablets, P-GFS in rats were separately listed as follows: T max 0.25 h, C max 474.96 ± 66.06 ng/ml and AUC0−∞ 733.32 ± 113.82 ng/ml h for GFS; T max 0.31 ± 0.043 h, C max 533.94 ± 106.54 ng/ml and AUC0−∞ 1151.38 ± 198.29 ng/ml h for Zhenyuan tablets; T max 0.5 h, C max 680.62 ± 138.051 ng/ml and

  17. Modelling snow cover duration improves predictions of functional and taxonomic diversity for alpine plant communities

    PubMed Central

    Carlson, Bradley Z.; Choler, Philippe; Renaud, Julien; Dedieu, Jean-Pierre; Thuiller, Wilfried

    2015-01-01

    Background and Aims Quantifying relationships between snow cover duration and plant community properties remains an important challenge in alpine ecology. This study develops a method to estimate spatial variation in energy availability in the context of a topographically complex, high-elevation watershed, which was used to test the explanatory power of environmental gradients both with and without snow cover in relation to taxonomic and functional plant diversity. Methods Snow cover in the French Alps was mapped at 15-m resolution using Landsat imagery for five recent years, and a generalized additive model (GAM) was fitted for each year linking snow to time and topography. Predicted snow cover maps were combined with air temperature and solar radiation data at daily resolution, summed for each year and averaged across years. Equivalent growing season energy gradients were also estimated without accounting for snow cover duration. Relationships were tested between environmental gradients and diversity metrics measured for 100 plots, including species richness, community-weighted mean traits, functional diversity and hyperspectral estimates of canopy chlorophyll content. Key Results Accounting for snow cover in environmental variables consistently led to improved predictive power as well as more ecologically meaningful characterizations of plant diversity. Model parameters differed significantly when fitted with and without snow cover. Filtering solar radiation with snow as compared without led to an average gain in R2 of 0·26 and reversed slope direction to more intuitive relationships for several diversity metrics. Conclusions The results show that in alpine environments high-resolution data on snow cover duration are pivotal for capturing the spatial heterogeneity of both taxonomic and functional diversity. The use of climate variables without consideration of snow cover can lead to erroneous predictions of plant diversity. The results further indicate that

  18. Improving ITS sequence data for identification of plant pathogenic fungi

    Treesearch

    R. Henrik Nilsson; Kevin D. Hyde; Julia Pawłowska; Martin Ryberg; Leho Tedersoo; Anders Bjørnsgard Aas; Siti A. Alias; Artur Alves; Cajsa Lisa Anderson; Alexandre Antonelli; A. Elizabeth Arnold; Barbara Bahnmann; Mohammad Bahram; Johan Bengtsson-Palme; Anna Berlin; Sara Branco; Putarak Chomnunti; Asha Dissanayake; Rein Drenkhan; Hanna Friberg; Tobias Guldberg Frøslev; Bettina Halwachs; Martin Hartmann; Beatrice Henricot; Ruvishika Jayawardena; Ari Jumpponen; Håvard Kauserud; Sonja Koskela; Tomasz Kulik; Kare Liimatainen; Björn D. Lindahl; Daniel Lindner; Jian-Kui Liu; Sajeewa Maharachchikumbura; Dimuthu Manamgoda; Svante Martinsson; Maria Alice Neves; Tuula Niskanen; Stephan Nylinder; Olinto Liparini Pereira; Danilo Batista Pinho; Teresita M. Porter; Valentin Queloz; Taavi Riit; Marisol Sánchez-García; Filipe de Sousa; Emil Stefańczyk; Mariusz Tadych; Susumu Takamatsu; Qing Tian; Dhanushka Udayanga; Martin Unterseher; Zheng Wang; Saowanee Wikee; Jiye Yan; Ellen Larsson; Karl-Henrik Larsson; Urmas Kõljalg; Kessy Abarenkov

    2014-01-01

    Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours. These taxa often have complex and poorly understood life cycles, lack observable, discriminatory morphological characters, and may not be amenable to in vitro culturing. As a result, species identification is frequently difficult...

  19. Amodeling framework for improving plant establishment during ecological restoration

    USDA-ARS?s Scientific Manuscript database

    Plants seeded during ecological restoration projects often perish en masse, and researchers are currently searching for traits promoting increased survival. In this study of a big sagebrush (Artemisia tridentata Nutt.) ecosystem, we found survivorship rankings of seeded grass species varied across 3...

  20. Texas plant retrofit improves throughput, C{sub 2} recovery

    SciTech Connect

    Lynch, J.T.; Pitman, R.N.

    1996-06-03

    GPM Gas Co.`s Goldsmith (Ector Co., Tex.) plant was recently converted from a nominal 90% ethane recovery and 86 MMscfd design capacity two-stage expansion process to a 95% ethane recovery and 135 MMscfd capacity. The project used the Gas Subcooled Process (GSP) design of Ortloff Engineers Ltd., Midland, Tex. The conversion required modification of existing expanders and chillers and addition of a plate-fin exchanger, an absorber column, and a set of pumps. Time from project approval through start-up was 5 months. NGL production was interrupted for 10 days while the plant was down for tie-ins and checkout. Plant throughput was compression-limited to operation at 130 MMscfd through late 1995. Compression to allow throughput of greater than 130 MMscfd was operational in late 1995. The demethanizer column and six of nine heat exchangers were reused in the Ortloff process retrofit. The demethanizer internals were changed out in 1995 in anticipation of higher throughput with the new compression. The two expanders were modified for parallel expander and booster compressor operation. Expander replacement was unnecessary. Similar retrofits of other GPM plants using GSP are currently under study.

  1. SUIC: Improving Opportunities through In-Plant Training.

    ERIC Educational Resources Information Center

    Skill Upgrading in Cleveland, OH.

    Skill Upgrading in Cleveland (SUIC) is one of three manpower training and upgrading organizations which was funded to replicate and further test the High Intensity Training (HIT) model for upgrading underemployed workers. This report is a summary of activities aimed at upgrading low-skill, low-wage workers within a plant setting and with small…

  2. Using plant canopy temperature to improve irrigated crop management

    USDA-ARS?s Scientific Manuscript database

    Remotely sensed plant canopy temperature has long been recognized as having potential as a tool for irrigation management. However, a number of barriers have prevented its routine use in practice, such as the spatial and temporal resolution of remote sensing platforms, limitations in computing capac...

  3. Vermicomposting of herbal pharmaceutical industry waste: earthworm growth, plant-available nutrient and microbial quality of end materials.

    PubMed

    Singh, Deepika; Suthar, Surindra

    2012-05-01

    Efforts were made to decompose herbal pharmaceutical industrial waste (HPIW) spiked with cow dung (CD) using Eisenia fetida. A total of five vermibeds: T(1) - HPIW (0%+CD 100%, control), T(2) - HPIW (25%), T(3) - HPIW (50%), T(4) - HPIW (75%) and T(5) - HPIW (100%) were used for vermicomposting. The changes in biology and chemistry of vermibeds were measured after ten days interval. E. fetida showed high growth and cocoon production rate in all vermibeds. The vermicomposted material contained great population of fungi 6.0-40.6 (CFU × 10(5)g(-1)), bacteria 220-1276.0 (CFU × 10(8)g(-1)) and actinomycetes 410.0-2962.0 (CFU × 10(5)g(-1)) than initial material. Vermicomposted material was rich in plant-available forms of nutrients (N-NO(3)(-),PO(4)(3-),available K and SO(4)(-2)). Results suggested that noxious industrial waste can be converted into valuable product for sustainable soil fertility programme.

  4. Are fire, soil fertility and toxicity, water availability, plant functional diversity, and litter decomposition related in a Neotropical savanna?

    PubMed

    Carvalho, Gustavo Henrique; Batalha, Marco Antônio; Silva, Igor Aurélio; Cianciaruso, Marcus Vinicius; Petchey, Owen L

    2014-07-01

    Understanding how biodiversity and ecosystem functioning respond to changes in the environment is fundamental to the maintenance of ecosystem function. In realistic scenarios, the biodiversity-ecosystem functioning path may account for only a small share of all factors determining ecosystem function. Here, we investigated the strength to which variations in environmental characteristics in a Neotropical savanna affected functional diversity and decomposition. We sought an integrative approach, testing a number of pairwise hypotheses about how the environment, biodiversity, and functioning were linked. We used structural equation modelling to connect fire frequency, soil fertility, exchangeable Al, water availability, functional diversity of woody plants, tree density, tree height, and litter decomposition rates in a causal chain. We found significant effects of soil nutrients, water availability, and Al on functional diversity and litter decomposition. Fire did not have a significant direct effect on functional diversity or litter decomposition. However, fire was connected to both variables through soil fertility. Functional diversity did not influence rates of litter decomposition. The mediated effects that emerged from pairwise interactions are encouraging not only for predicting the functional consequences of changes in environmental variables and biodiversity, but also to caution against predictions based on only environmental or only biodiversity change.

  5. Orthologous plant microRNAs: microregulators with great potential for improving stress tolerance in plants.

    PubMed

    Rajwanshi, Ravi; Chakraborty, Sreejita; Jayanandi, Karam; Deb, Bibhas; Lightfoot, David A

    2014-12-01

    Small RNAs that are highly conserved across many plant species are involved in stress responses. Plants are exposed to many types of unfavorable conditions during their life cycle that result in some degree of stress. Recent studies on microRNAs (miRNAs) have highlighted their great potential as regulators of stress tolerance in plants. One of the possible ways in which plants counter environmental stresses is by altering their gene expression by the action of miRNAs. miRNAs regulate the expression of target genes by hybridizing to their nascent reverse complementary sequences marking them for cleavage in the nucleus or translational repression in the cytoplasm. Some miRNAs have been reported to be key regulators in biotic as well as abiotic stress responses across many species. The present review highlights some of the regulatory roles of orthologous plant miRNAs in response to various types of stress conditions.

  6. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant

    PubMed Central

    Scobie, A. R.; Wilcock, C. C.

    2009-01-01

    Background and Aims Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. Methods The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Key Results Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0·25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Conclusions Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species. PMID

  7. Chemical and plant tests to assess the viability of amendments to reduce metal availability in mine soils and tailings.

    PubMed

    Rodríguez, Luis; Gómez, Rocío; Sánchez, Virtudes; Alonso-Azcárate, Jacinto

    2016-04-01

    The goal of this research was to assess the potential of several industrial wastes to immobilise metals in two polluted soils deriving from an old Pb/Zn mine. Two different approaches were used to assess the performance of different amendments: a chemical one, using extraction by ethylenediaminetetraacetic acid (EDTA), and a biological one, using Lupinus albus as a bio-indicator. Four amendments were used: inorganic sugar production waste (named 'sugar foam', SF), sludge from a drinking water treatment sludge (DWS), organic waste from olive mill waste (OMW) and paper mill sludge (PMS). Amendment to soil ratios ranged from 0.1 to 0.3 (w/w). All the amendments were capable of significantly decreasing (p < 0.05) EDTA-extractable Pb, Zn and Cu concentrations in the two soils used, with decreases in ranges 21-100, 25-100 and 2-100 % for Pb, Zn and Cu, respectively. The amendments tested were also effective in reducing the bioavailability of Pb and Zn for L. albus, which gave rise to a decrease in shoot metal accumulation by the lupine plants compared to that found in the control soil. That decrease reached up to 5.6 and 2.8 times for Pb and Zn, respectively, being statistically significant in most cases. Moreover, application of the OMW, DWS and SF amendments led to higher average values of plant biomass (up to 71%) than those obtained in the control soil. The results obtained showed the technology put forward to be a viable means of remediating mine soils as it led to a decrease in the availability and toxicity of metals and, thus, facilitated the growth of a vegetation layer.

  8. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant.

    PubMed

    Scobie, A R; Wilcock, C C

    2009-04-01

    Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0.25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species.

  9. Plant available nitrogen from anaerobically digested sludge and septic tank sludge applied to crops grown in the tropics.

    PubMed

    Sripanomtanakorn, S; Polprasert, C

    2002-04-01

    Agricultural land is an attractive alternative for the disposal of biosolids since it utilises the recyclable nutrients in the production of crops. In Thailand and other tropical regions, limited field-study information exists on the effect of biosolids management strategies on crop N utilisation and plant available N (PAN) of biosolids. A field study was conducted to quantify the PAN of the applied biosolids, and to evaluate the N uptake rates of some tropical crops. Sunflower (Helianthus annuus) and tomato (Lycopersicon esculentum) were chosen in this study. Two types of biosolids used were: anaerobically digested sludge and septic tank sludge. The soil is acid sulfate and is classified as Sulfic Tropaquepts with heavy clay in texture. The anaerobically digested sludge applied rates were: 0, 156 and 312 kg N ha(-1) for the sunflower plots, and 0, 586, and 1172 kg N ha(-1) for the tomato plots. The septic tank sludge applied rates were: 0, 95 and 190 kg N ha(-1) for the sunflower plots, and 0, 354 and 708 kg N ha(-1) for the tomato plots, respectively. The results indicated the feasibility of applying biosolids to grow tropical crops. The applications of the anaerobically digested sludge and the septic tank sludge resulted in the yields of sunflower seeds and tomato fruits and the plant N uptakes comparable or better than that applied with only the chemical fertiliser. The estimated PAN of the anaerobically digested sludge was about 27-42% of the sludge organic N during the growing season. For the septic tank sludge, the PAN was about 15-58% of the sludge organic N. It is interesting to observe that an increase of the rate of septic tank sludge incorporated into this heavy clay soil under the cropping system resulted in the decrease of N mineralisation rate. This situation could cause the reduction of yield and N uptake of crops.

  10. Understanding plant response to nitrogen limitation for the improvement of crop nitrogen use efficiency.

    PubMed

    Kant, Surya; Bi, Yong-Mei; Rothstein, Steven J

    2011-02-01

    Development of genetic varieties with improved nitrogen use efficiency (NUE) is essential for sustainable agriculture. Generally, NUE can be divided into two parts. First, assimilation efficiency involves nitrogen (N) uptake and assimilation and second utilization efficiency involves N remobilization. Understanding the mechanisms regulating these processes is crucial for the improvement of NUE in crop plants. One important approach is to develop an understanding of the plant response to different N regimes, especially to N limitation, using various methods including transcription profiling, analysing mutants defective in their normal response to N limitation, and studying plants that show better growth under N-limiting conditions. One can then attempt to improve NUE in crop plants using the knowledge gained from these studies. There are several potential genetic and molecular approaches for the improvement of crop NUE discussed in this review. Increased knowledge of how plants respond to different N levels as well as to other environmental conditions is required to achieve this.

  11. Improved wastewater treatment at Wheeling-Pittsburgh Steel Corporations`s Steubenville East Coke Plant

    SciTech Connect

    Goshe, A.J.; Nodianos, M.J.

    1995-12-01

    Wheeling-Pittsburgh Steel Corporation recently improved its wastewater treatment at it`s by-products coke plant. This has led to greatly improved effluent quality. Excess ammonia liquor, along with wastewater from the light oil recovery plant, desulfurization facility, and coal pile runoff, must be treated prior to being discharged into the Ohio River. This is accomplished using a biological wastewater treatment plant to remove 99.99% of the organic contaminants and ammonia. Biologically treated, clarified wastewater is now polished in the newly constructed tertiary treatment plant.

  12. Groundwater Availability Alters Soil-plant Nutrient Cycling in a Stand of Invasive, N-fixing Phreatophytes

    NASA Astrophysics Data System (ADS)

    Dudley, B. D.; Miyazawa, Y.; Hughes, F.; Ostertag, R.; Kettwich, S. K.; MacKenzie, R.; Dulaiova, H.; Waters, C. A.; Bishop, J.; Giambelluca, T. W.

    2013-12-01

    N-fixing phreatophytic trees are common in arid and semi-arid regions worldwide, and can play significant roles in modifying hydrology and soil-plant nutrient cycling where they are present. In light of reductions in groundwater levels in many arid regions we estimated annual transpiration rates at a stand level, and alterations to C, N and P accretion in soils as a function of groundwater depth in a ca.120 year old stand of Prosopis pallida along an elevation gradient in coastal leeward Hawaii. We measured sapflow and stand level sapwood area to quantify transpiration, and calculated groundwater transpiration rates using P. pallida stem water δ18O values. By measuring soil resistivity, we were able to compare the volume of groundwater transpired by these trees to groundwater depth across the stand. We examined nutrient deposition and accretion in soils in lowland areas of the stand with accessible shallow groundwater, compared to upland areas with no groundwater access, as indicated by stem water δ18O values. Resistivity results suggested that groundwater was at a height close to sea level throughout the stand. Transpiration was around 1900 m3 ha-1 year-1 in the areas of the stand closest to the sea (where groundwater was at around 1-4 m below ground level) and decreased to around a tenth of that volume where groundwater was not accessible. Litterfall rates over the course of the year studied were 17 times greater at lowland sites, but this litterfall contributed ca. 24 times the N, and 35 times the P of upland sites. Thus, groundwater access contributed to the total mass of nitrogen and phosphorus deposited in the form of litter through higher litter quantity and quality. Total N content of soils was 4.7 times greater and inorganic N pools were eight times higher at lowland plots. These results suggest that groundwater depth can have strong effects on soil-plant nutrient cycling, so that reductions in the availability of shallow groundwater are likely to impact

  13. Genetic improvement of plants for enhanced bio-ethanol production.

    PubMed

    Saha, Sanghamitra; Ramachandran, Srinivasan

    2013-04-01

    The present world energy situation urgently requires exploring and developing alternate, sustainable sources for fuel. Biofuels have proven to be an effective energy source but more needs to be produced to meet energy goals. Whereas first generation biofuels derived from mainly corn and sugarcane continue to be used and produced, the contentious debate between "feedstock versus foodstock" continues. The need for sources that can be grown under different environmental conditions has led to exploring newer sources. Lignocellulosic biomass is an attractive source for production of biofuel, but pretreatment costs to remove lignin are high and the process is time consuming. Genetically modified plants that have increased sugar or starch content, modified lignin content, or produce cellulose degrading enzymes are some options that are being explored and tested. This review focuses on current research on increasing production of biofuels by genetic engineering of plants to have desirable characteristics. Recent patents that have been filed in this area are also discussed.

  14. Food synergies for improving bioavailability of micronutrients from plant foods.

    PubMed

    Nair, K Madhavan; Augustine, Little Flower

    2018-01-01

    Plant foods are endowed with micronutrients but an understanding of bioavailability is essential in countries primarily dependent on plant based foods. Bioavailability depends majorly on food synergies. This review examines the nature of certain food synergies and methods to screen and establish it as a strategy to control micronutrient deficiency in the populations. Strong evidence on the synergistic effect of inclusion of vitamin C rich fruits and non-vegetarian foods in enhancing the bioavailability of iron has been demonstrated. Fat is found to be synergistic for vitamin A absorption. Red wine and protein have been explored for zinc absorption and effect of fat has been studied for vitamin D. Methods for screening of bioavailability, and biomarkers to demonstrate the synergistic effects of foods are required. Translation of food synergy as a strategy requires adaptation to the context and popularization of intelligent food synergies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Improving Plant Nitrogen Use Efficiency through Alteration of Amino Acid Transport Processes1[OPEN

    PubMed Central

    Perchlik, Molly

    2017-01-01

    Improving the efficiency of nitrogen (N) uptake and utilization in plants could potentially increase crop yields while reducing N fertilization and, subsequently, environmental pollution. Within most plants, N is transported primarily as amino acids. In this study, pea (Pisum sativum) plants overexpressing AMINO ACID PERMEASE1 (AAP1) were used to determine if and how genetic manipulation of amino acid transport from source to sink affects plant N use efficiency. The modified plants were grown under low, moderate, or high N fertilization regimes. The results showed that, independent of the N nutrition, the engineered plants allocate more N via the vasculature to the shoot and seeds and produce more biomass and higher seed yields than wild-type plants. Dependent on the amount of N supplied, the AAP1-overexpressing plants displayed improved N uptake or utilization efficiency, or a combination of the two. They also showed significantly increased N use efficiency in N-deficient as well as in N-rich soils and, impressively, required half the amount of N to produce as many fruits and seeds as control plants. Together, these data support that engineering N allocation from source to sink presents an effective strategy to produce crop plants with improved productivity as well as N use efficiency in a range of N environments. PMID:28733388

  16. An improved quantitative analysis method for plant cortical microtubules.

    PubMed

    Lu, Yi; Huang, Chenyang; Wang, Jia; Shang, Peng

    2014-01-01

    The arrangement of plant cortical microtubules can reflect the physiological state of cells. However, little attention has been paid to the image quantitative analysis of plant cortical microtubules so far. In this paper, Bidimensional Empirical Mode Decomposition (BEMD) algorithm was applied in the image preprocessing of the original microtubule image. And then Intrinsic Mode Function 1 (IMF1) image obtained by decomposition was selected to do the texture analysis based on Grey-Level Cooccurrence Matrix (GLCM) algorithm. Meanwhile, in order to further verify its reliability, the proposed texture analysis method was utilized to distinguish different images of Arabidopsis microtubules. The results showed that the effect of BEMD algorithm on edge preserving accompanied with noise reduction was positive, and the geometrical characteristic of the texture was obvious. Four texture parameters extracted by GLCM perfectly reflected the different arrangements between the two images of cortical microtubules. In summary, the results indicate that this method is feasible and effective for the image quantitative analysis of plant cortical microtubules. It not only provides a new quantitative approach for the comprehensive study of the role played by microtubules in cell life activities but also supplies references for other similar studies.

  17. Transportable nuclear power plant TEC-M with two reactor plants of improved safety

    SciTech Connect

    Ogloblin, B.G.; Sazonov, A.G.; Svishchev, A.M.; Gromov, B.F.; Zelensky, V.N.; Komkova, O.I.; Sidorov, V.I.; Tolstopyatov, V.P.; Toshinsky, G.I.

    1993-12-31

    Liquid metals are the best to meet the requirements of inherently safety nuclear power plants among the coolants used. A great experience has been gained in lead coolant power plant development and operation as applied to transportable power set-ups. Low chemical activity of this coolant with respect to air-water interaction is a determining factor for this coolant. The transportable nuclear power plant is described. It is intended to generate electric power for populated areas placed a long distance from the main electric power supply sources where it is difficult or not economical to deliver the conventional types of fuel. There are several remote areas in Siberia, Kamchatka in need of this type of power plant.

  18. Compressed Air System Optimization Project Saves Energy and Improves Production at a Citation Forging Plant

    SciTech Connect

    2003-05-01

    In the 1990s, a subsidiary of the Citation Corporation, Interstate Forging, implemented a compressed air system improvement project at its Milwaukee, Wisconsin, forging plant. This improvement enabled the plant to maintain an adequate and stable pressure level using fewer compressors, which led to improved product quality and lower production downtime. The project also yielded annual energy savings of 820,000 kWh and $45,000. With a total project cost of $67,000, the plant achieved a simple payback of just 1.5 years.

  19. Optimum combinations of visible and near-infrared reflectances for estimating the fraction of photosynthetically available radiation absorbed by plants

    NASA Technical Reports Server (NTRS)

    Podaire, Alain; Deschamps, Pierre-Yves; Frouin, R.; Asrar, Ghassem

    1991-01-01

    A useful parameter to estimate terrestrial primary productivity, that can be sensed from space, is the daily averaged fraction of Photosynthetically Available Radiation (PAR) absorbed by plants. To evaluate this parameter, investigators have relied on the fact that the relative amount of radiation reflected by a vegetated surface in the visible and near infrared depends on the fraction of the surface covered by the vegetation and therefore, correlates with absorbed PAR. They have used vegetation indices, namely normalized difference and simple ratio, to derive absorbed PAR. The problem with normalized difference and simple ratio is first, they are non linear functions of radiance or reflectance and therefore, cannot be readily applied to heterogeneous targets, second, they are used in generally nonlinear relationships, which make time integrals of the indices not proportional to primary productivity, and third, the relationships depend strongly on the type of canopy and background. To remove these limitations, linear combinations of visible and near infrared reflectances at optimum (one or two) viewing zenith angles are proposed.

  20. The influence of pH and organic matter content in paddy soil on heavy metal availability and their uptake by rice plants.

    PubMed

    Zeng, Fanrong; Ali, Shafaqat; Zhang, Haitao; Ouyang, Younan; Qiu, Boyin; Wu, Feibo; Zhang, Guoping

    2011-01-01

    The experiments were done to investigate the effect of soil pH and organic matter content on EDTA-extractable heavy metal contents in soils and heavy metal concentrations in rice straw and grains. EDTA-extractable Cr contents in soils and concentrations in rice tissues were negatively correlated with soil pH, but positively correlated with organic matter content. The combination of soil pH and organic matter content would produce the more precise regression models for estimation of EDTA-Cu, Pb and Zn contents in soils, demonstrating the distinct effect of the two factors on the availability of these heavy metals in soils. Soil pH greatly affected heavy metal concentrations in rice plants. Furthermore, inclusion of other soil properties in the stepwise regression analysis improved the regression models for predicting straw Fe and grain Zn concentrations, indicating that other soil properties should be taken into consideration for precise predicting of heavy metal concentrations in rice plants.

  1. Inoculating chlamydospores of Trichoderma asperellum SM-12F1 changes arsenic availability and enzyme activity in soils and improves water spinach growth.

    PubMed

    Su, Shiming; Zeng, Xibai; Bai, Lingyu; Williams, Paul N; Wang, Yanan; Zhang, Lili; Wu, Cuixia

    2017-05-01

    Arsenic (As)-contaminated agricultural soils threaten crop yields and pose a human health risk. Augmentation of exogenous microorganisms exhibiting plant-growth promoting and As speciation changing shows potential to improve crop growth and change soil As availability. Trichoderma asperellum SM-12F1 exhibiting both traits was developed into chlamydospores to improve its persistence in contaminated soils. After inoculation, As availability and enzyme activity in two types of soils and the growth as well as As uptake of water spinach (Ipomoea aquatic Forsk.) were investigated. The results indicated that inoculation significantly improved water spinach growth in both soils. Inoculating chlamydospores at 5% significantly increased As concentration (139%), bioconcentration factor (150%), and translocation factor (150%) in water spinach grown in Chenzhou (CZ) soils, while no significant change for these in Shimen (SM) soils. Inoculating chlamydospores at 5% caused a significant increase (16%) of available As content in CZ soils, while a significant decrease (13%) in SM soils. Inoculation significantly caused As methylation in both soils, while significant As reduction merely observed in CZ soils. The differential changes in available As contents in both soils were attributed to the soil pH, As fractionations and speciation characteristics. Furthermore, Inoculating chlamydospores at 5% significantly improved the activities of β-glucosidase (155%), chitinase (211%), and phosphatase (108%) in SM soils, while significant decreases in β-glucosidase (81%), phosphatase (54%), aminopeptidase (60%), and catalase (67%) in CZ soils. Bioaugmentation and As availability change were responsible for this result. These observations will be helpful for the application of fungal chlamydospores in the future bioremediation. Copyright © 2017. Published by Elsevier Ltd.

  2. Forward genetic screening for the improved production of fermentable sugars from plant biomass.

    PubMed

    Stamatiou, George; Vidaurre, Danielle P; Shim, Isaac; Tang, Xurong; Moeder, Wolfgang; Bonetta, Dario; McCourt, Peter

    2013-01-01

    With their unique metabolism and the potential to produce large amounts of biomass, plants are an excellent bio-energy feedstock for a variety of industrial purposes. Here we developed a high-throughput strategy, using the model plant Arabidopsis thaliana, to identify mutants with improved sugar release from plant biomass. Molecular analysis indicates a variety of processes including starch degradation, cell wall composition and polar transport of the plant hormone auxin can contribute to this improved saccharification. To demonstrate translatability, polar auxin transport in maize was either genetically or chemical inhibited and this also resulted in increased sugar release from plant tissues. Our forward genetic approach using Arabidopsis not only uncovers new functions that contribute to cell wall integrity but also demonstrates that information gleaned from this genetic model can be directly translated to monocotyledonous crops such as maize to improve sugar extractability from biomass.

  3. 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. ...

  4. Short range attraction of Ceratitis capitata (Diptera: Tephritidae) sterile males to six commercially available plant essential oils

    USDA-ARS?s Scientific Manuscript database

    Plant essential oils have a number of roles in insect pest management. For male Ceratitis capitata, this includes use of angelica seed oil as long range attractants and ginger root oil as aromatherapy, which is exposure to sterile males to increase mating success. Neither of these plants are hosts f...

  5. Interactions between elevated atmospheric CO2 and defoliation on North American rangeland plant species at low and high N availability

    USDA-ARS?s Scientific Manuscript database

    Semi-arid rangelands are expected to be highly sensitive to global change, but few studies have explicitly investigated interactions between increased atmospheric CO2 and plant defoliation (such as occurs with animal grazing). This experiment subjected intact plant-soil cylinders from the Wyoming pr...

  6. Adaptation of a commercially available 200 kW natural gas fuel cell power plant for operation on a hydrogen rich gas stream

    SciTech Connect

    Maston, V.A.

    1997-12-01

    International Fuel Cells (IFC) has designed a hydrogen fueled fuel cell power plant based on a modification of its standard natural gas fueled PC25{trademark} C fuel cell power plant. The natural gas fueled PC25 C is a 200 kW, fuel cell power plant that is commercially available. The program to accomplish the fuel change involved deleting the natural gas processing elements, designing a new fuel pretreatment subsystem, modifying the water and thermal management subsystem, developing a hydrogen burner to combust unconsumed hydrogen, and modifying the control system. Additionally, the required modifications to the manufacturing and assembly procedures necessary to allow the hydrogen fueled power plant to be manufactured in conjunction with the on-going production of the standard PC25 C power plants were identified. This work establishes the design and manufacturing plan for the 200 kW hydrogen fueled PC25 power plant.

  7. Manipulating plant geometry to improve microclimate, grain yield, and harvest index in grain sorghum

    PubMed Central

    Stewart, Bob A.; Xue, Qingwu; Chen, Yuanquan

    2017-01-01

    Cultivar selection, planting geometry, and plant population are the key factors determining grain sorghum yields in water deficit areas. The objective of this study was to investigate whether clump geometry (three plants clustered) improves microclimate within crop canopy when plants are grown under varying water levels. In a 2-yr sorghum (Sorghum bicolor L. Moench) greenhouse study, plants were grown at two geometries (clump and conventional evenly spaced planting, ESP), two water levels (high and low, representing well-watered and water-limited condition, respectively), and three soil surface treatments (lid covered, straw-mulched, and bare). Air temperature and relative humidity (RH) within the plant canopy were measured every five minutes at different growth stages. Mean vapor pressure deficits (VPDs) within the clumps were consistently lower than those for ESPs, indicating that clumps improved the microclimate. Clumps had significantly higher harvest index (HI) compared to ESPs (0.48 vs. 0.43), which was largely due to clumps having an average of 0.4 tillers per plant compared to 1.2 tillers per plant for ESPs. Grain yield in the current study was similar between clumps and ESPs. However, our results suggest that improved microclimate was likely a reason for clumps producing significantly higher grain yields compared to ESPs in previous studies. PMID:28264051

  8. Plant plasma membrane proteomics for improving cold tolerance.

    PubMed

    Takahashi, Daisuke; Li, Bin; Nakayama, Takato; Kawamura, Yukio; Uemura, Matsuo

    2013-01-01

    Plants are always exposed to various stresses. We have focused on freezing stress, which causes serious problems for agricultural management. When plants suffer freeze-induced damage, the plasma membrane is thought to be the primary site of injury because of its central role in regulation of various cellular processes. Cold tolerant species, however, adapt to such freezing conditions by modifying cellular components and functions (cold acclimation). One of the most important adaptation mechanisms to freezing is alteration of plasma membrane compositions and functions. Advanced proteomic technologies have succeeded in identification of many candidates that may play roles in adaptation of the plasma membrane to freezing stress. Proteomics results suggest that adaptations of plasma membrane functions to low temperature are associated with alterations of protein compositions during cold acclimation. Some of proteins identified by proteomic approaches have been verified their functional roles in freezing tolerance mechanisms further. Thus, accumulation of proteomic results in the plasma membrane is of importance for application to molecular breeding efforts to increase cold tolerance in crops.

  9. Enhancing auxin accumulation in maize root tips improves root growth and dwarfs plant height.

    PubMed

    Li, Zhaoxia; Zhang, Xinrui; Zhao, Yajie; Li, Yujie; Zhang, Guangfeng; Peng, Zhenghua; Zhang, Juren

    2017-05-12

    Maize is a globally important food, feed crop and raw material for the food and energy industry. Plant architecture optimization plays important roles in maize yield improvement. PIN-FORMED (PIN) proteins are important for regulating auxin spatiotemporal asymmetric distribution in multiple plant developmental processes. In this study, ZmPIN1a overexpression in maize increased the number of lateral roots and inhibited their elongation, forming a developed root system with longer seminal roots and denser lateral roots. ZmPIN1a overexpression reduced plant height, internode length and ear height. This modification of the maize phenotype increased the yield under high-density cultivation conditions, and the developed root system improved plant resistance to drought, lodging and a low-phosphate environment. IAA concentration, transport capacity determination and application of external IAA indicated that ZmPIN1a overexpression led to increased IAA transport from shoot to root. The increase in auxin in the root enabled the plant to allocate more carbohydrates to the roots, enhanced the growth of the root and improved plant resistance to environmental stress. These findings demonstrate that maize plant architecture can be improved by root breeding to create an ideal phenotype for further yield increases. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  10. Marble wastes and pig slurry improve the environmental and plant-relevant properties of mine tailings.

    PubMed

    Kabas, S; Faz, A; Acosta, J A; Arocena, J M; Zornoza, R; Martínez-Martínez, S; Carmona, D M

    2014-02-01

    Poor soil fertility is often the biggest challenge to the establishment of vegetation in mine wastes deposits. We conducted field trials in the El Gorguel and El Lirio sites in SE Spain, two representative tailing ponds of similar properties except for pH, to understand the environmental and plant-relevant benefits of marble waste (MW) and pig slurry (PS) applications to mine tailings. Low pH (5.4) tailings (El Lirio) exhibit reduction of up to fourfold in bio-availability of metals as shown by the DTPA-Zn, Pb, water-soluble Zn, Pb and up to 3× for water-soluble Cd. Tailings in El Gorguel have high pH (7.4) and did not exhibit significant trends in the reductions of water-extractable Zn, Pb, Cd and Cu. Improvements to the edaphic (plant-relevant) properties of tailings after the amendments are not as sensitive to pH compared to the environmental characteristics. The two sites had increases in aggregate stability, organic matter (total N and organic C) although total N is higher in the El Gorguel (up to 212 μg N kg(-1)) than the El Lirio (up to 26 μg N kg(-1)). However, cation exchange capacities are similar in both sites at 15.2 cmol(+) kg(-1). We conclude that the characteristics, especially pH, of tailing materials significantly influence the fate of metals but not improvements to plant-relevant properties such as cation exchange capacity and aggregate stability 1 year after the application of MW and PS amendments.

  11. Regulation of Na+ and K+ homeostasis in plants: towards improved salt stress tolerance in crop plants.

    PubMed

    Almeida, Diego M; Oliveira, M Margarida; Saibo, Nelson J M

    2017-03-27

    Soil salinity is a major abiotic stress that results in considerable crop yield losses worldwide. However, some plant genotypes show a high tolerance to soil salinity, as they manage to maintain a high K+/Na+ ratio in the cytosol, in contrast to salt stress susceptible genotypes. Although, different plant genotypes show different salt tolerance mechanisms, they all rely on the regulation and function of K+ and Na+ transporters and H+ pumps, which generate the driving force for K+ and Na+ transport. In this review we will introduce salt stress responses in plants and summarize the current knowledge about the most important ion transporters that facilitate intra- and intercellular K+ and Na+ homeostasis in these organisms. We will describe and discuss the regulation and function of the H+-ATPases, H+-PPases, SOS1, HKTs, and NHXs, including the specific tissues where they work and their response to salt stress.

  12. Regulation of Na+ and K+ homeostasis in plants: towards improved salt stress tolerance in crop plants

    PubMed Central

    Almeida, Diego M.; Oliveira, M. Margarida; Saibo, Nelson J. M.

    2017-01-01

    Abstract Soil salinity is a major abiotic stress that results in considerable crop yield losses worldwide. However, some plant genotypes show a high tolerance to soil salinity, as they manage to maintain a high K+/Na+ ratio in the cytosol, in contrast to salt stress susceptible genotypes. Although, different plant genotypes show different salt tolerance mechanisms, they all rely on the regulation and function of K+ and Na+ transporters and H+ pumps, which generate the driving force for K+ and Na+ transport. In this review we will introduce salt stress responses in plants and summarize the current knowledge about the most important ion transporters that facilitate intra- and intercellular K+ and Na+ homeostasis in these organisms. We will describe and discuss the regulation and function of the H+-ATPases, H+-PPases, SOS1, HKTs, and NHXs, including the specific tissues where they work and their response to salt stress. PMID:28350038

  13. Novel enabling technologies of gene isolation and plant transformation for improved crop protection

    SciTech Connect

    Torok, Tamas

    2013-02-04

    Meeting the needs of agricultural producers requires the continued development of improved transgenic crop protection products. The completed project focused on developing novel enabling technologies of gene discovery and plant transformation to facilitate the generation of such products.

  14. Remote Sensing and Modeling for Improving Operational Aquatic Plant Management

    NASA Technical Reports Server (NTRS)

    Bubenheim, Dave

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California’s water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  15. Using remote sensing to calculate plant available nitrogen needed by crops on swine factory farm sprayfields in North Carolina

    NASA Astrophysics Data System (ADS)

    Christenson, Elizabeth; Serre, Marc

    2015-10-01

    North Carolina (NC) is the second largest producer of hogs in the United States with Duplin county, NC having the densest population of hogs in the world. In NC, liquid swine manure is generally stored in open-air lagoons and sprayed onto sprayfields with sprinkler systems to be used as fertilizer for crops. Swine factory farms, termed concentrated animal feeding operations (CAFOs), are regulated by the Department of Environment and Natural Resources (DENR) based on nutrient management plans (NMPs) having balanced plant available nitrogen (PAN). The estimated PAN in liquid manure being sprayed must be less than the estimated PAN needed crops during irrigation. Estimates for PAN needed by crops are dependent on crop and soil types. Objectives of this research were to develop a new, time-efficient method to identify PAN needed by crops on Duplin county sprayfields for years 2010-2014. Using remote sensing data instead of NMP data to identify PAN needed by crops allowed calendar year identification of which crops were grown on sprayfields instead of a five-year range of values. Although permitted data have more detailed crop information than remotely sensed data, identification of PAN needed by crops using remotely sensed data is more time efficient, internally consistent, easily publically accessible, and has the ability to identify annual changes in PAN on sprayfields. Once PAN needed by crops is known, remote sensing can be used to quantify PAN at other spatial scales, such as sub-watershed levels, and can be used to inform targeted water quality monitoring of swine CAFOs.

  16. An improved, low-cost, hydroponic system for growing Arabidopsis and other plant species under aseptic conditions.

    PubMed

    Alatorre-Cobos, Fulgencio; Calderón-Vázquez, Carlos; Ibarra-Laclette, Enrique; Yong-Villalobos, Lenin; Pérez-Torres, Claudia-Anahí; Oropeza-Aburto, Araceli; Méndez-Bravo, Alfonso; González-Morales, Sandra-Isabel; Gutiérrez-Alanís, Dolores; Chacón-López, Alejandra; Peña-Ocaña, Betsy-Anaid; Herrera-Estrella, Luis

    2014-03-21

    Hydroponics is a plant growth system that provides a more precise control of growth media composition. Several hydroponic systems have been reported for Arabidopsis and other model plants. The ease of system set up, cost of the growth system and flexibility to characterize and harvest plant material are features continually improved in new hydroponic system reported. We developed a hydroponic culture system for Arabidopsis and other model plants. This low cost, proficient, and novel system is based on recyclable and sterilizable plastic containers, which are readily available from local suppliers. Our system allows a large-scale manipulation of seedlings. It adapts to different growing treatments and has an extended growth window until adult plants are established. The novel seed-holder also facilitates the transfer and harvest of seedlings. Here we report the use of our hydroponic system to analyze transcriptomic responses of Arabidopsis to nutriment availability and plant/pathogen interactions. The efficiency and functionality of our proposed hydroponic system is demonstrated in nutrient deficiency and pathogenesis experiments. Hydroponically grown Arabidopsis seedlings under long-time inorganic phosphate (Pi) deficiency showed typical changes in root architecture and high expression of marker genes involved in signaling and Pi recycling. Genome-wide transcriptional analysis of gene expression of Arabidopsis roots depleted of Pi by short time periods indicates that genes related to general stress are up-regulated before those specific to Pi signaling and metabolism. Our hydroponic system also proved useful for conducting pathogenesis essays, revealing early transcriptional activation of pathogenesis-related genes.

  17. Global Change and Response of Coastal Dune Plants to the Combined Effects of Increased Sand Accretion (Burial) and Nutrient Availability

    PubMed Central

    Frosini, Silvia; Lardicci, Claudio; Balestri, Elena

    2012-01-01

    Coastal dune plants are subjected to natural multiple stresses and vulnerable to global change. Some changes associated with global change could interact in their effects on vegetation. As vegetation plays a fundamental role in building and stabilizing dune systems, effective coastal habitat management requires a better understanding of the combined effects of such changes on plant populations. A manipulative experiment was conducted along a Mediterranean dune system to examine the individual and combined effects of increased sediment accretion (burial) and nitrogen enrichment associated with predicted global change on the performance of young clones of Sporobolus virginicus, a widespread dune stabilizing species. Increased burial severity resulted in the production of taller but thinner shoots, while nutrient enrichment stimulated rhizome production. Nutrient enrichment increased total plant biomass up to moderate burial levels (50% of plant height), but it had not effect at the highest burial level (100% of plant height). The effects of such factors on total biomass, shoot biomass and branching were influenced by spatial variation in natural factors at the scale of hundreds of metres. These results indicate that the effects of burial and nutrient enrichment on plant performance were not independent. Their combined effects may not be predicted by knowing the individual effects, at least under the study conditions. Under global change scenarios, increased nutrient input could alleviate nutrient stress in S. virginicus, enhancing clonal expansion and productivity, but this benefit could be offset by increased sand accretion levels equal or exceeding 100% of plant height. Depletion of stored reserves for emerging from sand could increase plant vulnerability to other stresses in the long-term. The results emphasize the need to incorporate statistical designs for detecting non-independent effects of multiple changes and adequate spatial replication in future works to

  18. Global change and response of coastal dune plants to the combined effects of increased sand accretion (burial) and nutrient availability.

    PubMed

    Frosini, Silvia; Lardicci, Claudio; Balestri, Elena

    2012-01-01

    Coastal dune plants are subjected to natural multiple stresses and vulnerable to global change. Some changes associated with global change could interact in their effects on vegetation. As vegetation plays a fundamental role in building and stabilizing dune systems, effective coastal habitat management requires a better understanding of the combined effects of such changes on plant populations. A manipulative experiment was conducted along a Mediterranean dune system to examine the individual and combined effects of increased sediment accretion (burial) and nitrogen enrichment associated with predicted global change on the performance of young clones of Sporobolus virginicus, a widespread dune stabilizing species. Increased burial severity resulted in the production of taller but thinner shoots, while nutrient enrichment stimulated rhizome production. Nutrient enrichment increased total plant biomass up to moderate burial levels (50% of plant height), but it had not effect at the highest burial level (100% of plant height). The effects of such factors on total biomass, shoot biomass and branching were influenced by spatial variation in natural factors at the scale of hundreds of metres. These results indicate that the effects of burial and nutrient enrichment on plant performance were not independent. Their combined effects may not be predicted by knowing the individual effects, at least under the study conditions. Under global change scenarios, increased nutrient input could alleviate nutrient stress in S. virginicus, enhancing clonal expansion and productivity, but this benefit could be offset by increased sand accretion levels equal or exceeding 100% of plant height. Depletion of stored reserves for emerging from sand could increase plant vulnerability to other stresses in the long-term. The results emphasize the need to incorporate statistical designs for detecting non-independent effects of multiple changes and adequate spatial replication in future works to

  19. Randomized trial of the Availability, Responsiveness and Continuity (ARC) organizational intervention for improving youth outcomes in community mental health programs.

    PubMed

    Glisson, Charles; Hemmelgarn, Anthony; Green, Philip; Williams, Nathaniel J

    2013-05-01

    The primary objective of the study was to assess whether the Availability, Responsiveness and Continuity (ARC) organizational intervention improved youth outcomes in community based mental health programs. The second objective was to assess whether programs with more improved organizational social contexts following the 18-month ARC intervention had better youth outcomes than programs with less improved social contexts. Eighteen community mental health programs that serve youth between the ages of 5 and 18 were randomly assigned to ARC or control conditions. Clinicians (n = 154) in the participating programs completed the Organizational Social Context (OSC) measure at baseline and following the 18-month ARC organizational intervention. Caregivers of 393 youth who were served by the 18 programs (9 in ARC and 9 in control) completed the Shortform Assessment for Children (SAC) once a month for six months beginning at intake. Hierarchical linear models (HLM) analyses indicated that youth outcomes were significantly better in the programs that completed the 18 month ARC intervention. HLM analyses also showed that youth outcomes were best in the programs with the most improved organizational social contexts following the 18 month ARC intervention. Youth outcomes in community mental health programs can be improved with the ARC organizational intervention and outcomes are best in programs that make the most improvements in organizational social context. The relationships linking ARC, organizational social context, and youth outcomes suggest that service improvement efforts will be more successful if those efforts include strategies to improve the organizational social contexts in which the services are embedded. Copyright © 2013 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. A High-Value Best-Value Approach to Public Shipyard Human Capital Management to Improve Ship Availability

    DTIC Science & Technology

    2015-09-01

    VALUE APPROACH TO PUBLIC SHIPYARD HUMAN CAPITAL MANAGEMENT TO IMPROVE SHIP AVAILABILITY by Shannon R. Buckley September 2015 Thesis...0704–0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing...4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) 2

  1. The Air Force Needs to Improve Cost-Effectiveness and Availability of the Joint Surveillance Target Attack Radar System (Redacted)

    DTIC Science & Technology

    2016-11-01

    Introduction Objective We determined whether the Air Force made cost-effective purchases on the performance-based logistics ( PBL ) contract to support...logistics ( PBL ) contract to support JSTARS. Specifically, the JSTARS contracting officer did not establish adequate oversight procedures to validate the...must develop and implement PBL strategies that improve total system availability while minimizing cost and the size of spare parts inventory

  2. Hydroponics: A Versatile System to Study Nutrient Allocation and Plant Responses to Nutrient Availability and Exposure to Toxic Elements.

    PubMed

    Nguyen, Nga T; McInturf, Samuel A; Mendoza-Cózatl, David G

    2016-07-13

    Hydroponic systems have been utilized as one of the standard methods for plant biology research and are also used in commercial production for several crops, including lettuce and tomato. Within the plant research community, numerous hydroponic systems have been designed to study plant responses to biotic and abiotic stresses. Here we present a hydroponic protocol that can be easily implemented in laboratories interested in pursuing studies on plant mineral nutrition. This protocol describes the hydroponic system set up in detail and the preparation of plant material for successful experiments. Most of the materials described in this protocol can be found outside scientific supply companies, making the set up for hydroponic experiments less expensive and convenient. The use of a hydroponic growth system is most advantageous in situations where the nutrient media need to be well controlled and when intact roots need to be harvested for downstream applications. We also demonstrate how nutrient concentrations can be modified to induce plant responses to both essential nutrients and toxic non-essential elements.

  3. Hydroponics: A Versatile System to Study Nutrient Allocation and Plant Responses to Nutrient Availability and Exposure to Toxic Elements

    PubMed Central

    Nguyen, Nga T.; McInturf, Samuel A.; Mendoza-Cózatl, David G.

    2016-01-01

    Hydroponic systems have been utilized as one of the standard methods for plant biology research and are also used in commercial production for several crops, including lettuce and tomato. Within the plant research community, numerous hydroponic systems have been designed to study plant responses to biotic and abiotic stresses. Here we present a hydroponic protocol that can be easily implemented in laboratories interested in pursuing studies on plant mineral nutrition. This protocol describes the hydroponic system set up in detail and the preparation of plant material for successful experiments. Most of the materials described in this protocol can be found outside scientific supply companies, making the set up for hydroponic experiments less expensive and convenient. The use of a hydroponic growth system is most advantageous in situations where the nutrient media need to be well controlled and when intact roots need to be harvested for downstream applications. We also demonstrate how nutrient concentrations can be modified to induce plant responses to both essential nutrients and toxic non-essential elements. PMID:27500800

  4. Overexpression of monoubiquitin improves photosynthesis in transgenic tobacco plants following high temperature stress.

    PubMed

    Tian, Fengxia; Gong, Jiangfeng; Zhang, Jin; Feng, Yanan; Wang, Guokun; Guo, Qifang; Wang, Wei

    2014-09-01

    The ubiquitin/26S proteasome system (Ub/26S) is implicated in abiotic stress responses in plants. In this paper, transgenic tobacco plants overexpressing Ta-Ub2 from wheat were used to study the functions of Ub in the improvement of photosynthesis under high temperature (45°C) stress. We observed higher levels of Ub conjugates in transgenic plants under high temperature stress conditions compared to wild type (WT) as a result of the constitutive overexpression of Ta-Ub2, suggesting increased protein degradation by the 26S proteasome system under high temperature stress. Overexpressing Ub increased the photosynthetic rate (Pn) of transgenic tobacco plants, consistent with the improved ATPase activity in the thylakoid membrane and enhanced efficiency of PSII photochemistry. The higher D1 protein levels following high temperature stress in transgenic plants than WT were also observed. These findings imply that Ub may be involved in tolerance of photosynthesis to high temperature stress in plants. Compared with WT, the transgenic plants showed lower protein carbonylation and malondialdehyde (MDA) levels, less reactive oxygen species (ROS) accumulation, but higher antioxidant enzyme activity under high temperature stress. These findings suggest that the improved antioxidant capacity of transgenic plants may be one of the most important mechanisms underlying Ub-regulated high temperature tolerance.

  5. Improvement of growth rate of plants by bubble discharge in water

    NASA Astrophysics Data System (ADS)

    Takahata, Junichiro; Takaki, Koichi; Satta, Naoya; Takahashi, Katsuyuki; Fujio, Takuya; Sasaki, Yuji

    2015-01-01

    The effect of bubble discharge in water on the growth rate of plants was investigated experimentally for application to plant cultivation systems. Spinach (Spinacia oleracea), radish (Raphanus sativus var. sativus), and strawberry (Fragaria × ananassa) were used as specimens to clarify the effect of the discharge treatment on edible parts of the plants. The specimens were cultivated in pots filled with artificial soil, which included chicken manure charcoal. Distilled water was sprayed on the artificial soil and drained through a hole in the pots to a water storage tank. The water was circulated from the water storage tank to the cultivation pots after 15 or 30 min discharge treatment on alternate days. A magnetic compression-type pulsed power generator was used to produce the bubble discharge with a repetition rate of 250 pps. The plant height in the growth phase and the dry weight of the harvested plants were improved markedly by the discharge treatment in water. The soil and plant analyzer development (SPAD) value of the plants also improved in the growth phase of the plants. The concentration of nitrate nitrogen, which mainly contributed to the improvement of the growth rate, in the water increased with the discharge treatment. The Brix value of edible parts of Fragaria × ananassa increased with the discharge treatment. The inactivation of bacteria in the water was also confirmed with the discharge treatment.

  6. Improvement of water desalination technologies in reverse osmosis plants

    NASA Astrophysics Data System (ADS)

    Vysotskii, S. P.; Konoval'chik, M. V.; Gul'ko, S. E.

    2017-07-01

    The strengthening of requirements for the protection of surface-water sources and increases in the cost of reagents lead to the necessity of using membrane (especially, reverse osmosis) technologies of water desalination as an alternative to ion-exchange technologies. The peculiarities of using reverse osmosis technologies in the desalination of waters with an increased salinity have been discussed. An analogy has been made between the dependence of the adsorptive capacity of ion-exchange resins on the reagent consumption during ion exchange and the dependence of the specific ion flux on the voltage in the electrodialysis and productivity of membrane elements on the excess of the pressure of source water over the osmotic pressure in reverse osmosis. It has been proposed to regulate the number of water desalination steps in reverse osmosis plants, which makes it possible to flexibly change the productivity of equipment and the level of desalinization, depending on the requirements for the technological process. It is shown that the selectivity of reverse osmotic membranes with respect to bivalent ions (calcium, magnesium, and sulfates) is approximately four times higher than the selectivity with respect to monovalent ions (sodium and chlorine). The process of desalination in reverse osmosis plants depends on operation factors, such as the salt content and ion composition of source water, the salt content of the concentrate, and the temperatures of solution and operating pressure, and the design features of devices, such as the length of the motion of the desalination water flux, the distance between membranes, and types of membranes and turbulators (spacers). To assess the influence of separate parameters on the process of reverse osmosis desalination of water solutions, we derived criteria equations by compiling problem solution matrices on the basis of the dimensional method, taking into account the Huntley complement. The operation of membrane elements was

  7. Improvement of plant abiotic stress tolerance through modulation of the polyamine pathway.

    PubMed

    Shi, Haitao; Chan, Zhulong

    2014-02-01

    Polyamines (mainly putrescine (Put), spermidine (Spd), and spermine (Spm)) have been widely found in a range of physiological processes and in almost all diverse environmental stresses. In various plant species, abiotic stresses modulated the accumulation of polyamines and related gene expression. Studies using loss-of-function mutants and transgenic overexpression plants modulating polyamine metabolic pathways confirmed protective roles of polyamines during plant abiotic stress responses, and indicated the possibility to improve plant tolerance through genetic manipulation of the polyamine pathway. Additionally, putative mechanisms of polyamines involved in plant abiotic stress tolerance were thoroughly discussed and crosstalks among polyamine, abscisic acid, and nitric oxide in plant responses to abiotic stress were emphasized. Special attention was paid to the interaction between polyamine and reactive oxygen species, ion channels, amino acid and carbon metabolism, and other adaptive responses. Further studies are needed to elucidate the polyamine signaling pathway, especially polyamine-regulated downstream targets and the connections between polyamines and other stress responsive molecules.

  8. Assessing the ecotoxicological effects of long-term contaminated mine soils on plants and earthworms: relevance of soil (total and available) and body concentrations.

    PubMed

    García-Gómez, Concepción; Esteban, Elvira; Sánchez-Pardo, Beatriz; Fernández, María Dolores

    2014-09-01

    The interactions and relevance of the soil (total and available) concentrations, accumulation, and acute toxicity of several essential and non-essential trace elements were investigated to determine their importance in environmental soil assessment. Three plant species (T. aestivum, R. sativum, and V. sativa) and E. fetida were simultaneously exposed for 21 days to long-term contaminated soils collected from the surroundings of an abandoned pyrite mine. The soils presented different levels of As and metals, mainly Zn and Cu, and were tested at different soil concentrations [12.5, 25, 50, and 100% of contaminated soil/soil (w/w)] to increase the range of total and available soil concentrations necessary for the study. The total concentrations in the soils (of both As and metals) were better predictors of earthworm uptake than were the available concentrations. In plants, the accumulation of metals was related to the available concentrations of Zn and Cu, which could indicate that plants and earthworms accumulate elements from different pools of soil contaminants. Moreover, Zn and Cu, which are essential elements, showed controlled uptake at low concentrations. The external metal concentrations predicted earthworm mortality, whereas in plants, the effects on growth were correlated to the As and metal contents in the plants. In general, the bioaccumulation factors were lower at higher exposure levels, which implies the existence of auto-regulation in the uptake of both essential and non-essential elements by plants and earthworms.

  9. 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.

  10. A critical review on the improvement of photosynthetic carbon assimilation in C3 plants using genetic engineering.

    PubMed

    Ruan, Cheng-Jiang; Shao, Hong-Bo; Teixeira da Silva, Jaime A

    2012-03-01

    Global warming is one of the most serious challenges facing us today. It may be linked to the increase in atmospheric CO2 and other greenhouse gases (GHGs), leading to a rise in sea level, notable shifts in ecosystems, and in the frequency and intensity of wild fires. There is a strong interest in stabilizing the atmospheric concentration of CO2 and other GHGs by decreasing carbon emission and/or increasing carbon sequestration. Biotic sequestration is an important and effective strategy to mitigate the effects of rising atmospheric CO2 concentrations by increasing carbon sequestration and storage capacity of ecosystems using plant photosynthesis and by decreasing carbon emission using biofuel rather than fossil fuel. Improvement of photosynthetic carbon assimilation, using transgenic engineering, potentially provides a set of available and effective tools for enhancing plant carbon sequestration. In this review, firstly different biological methods of CO2 assimilation in C3, C4 and CAM plants are introduced and three types of C4 pathways which have high photosynthetic performance and have evolved as CO2 pumps are briefly summarized. Then (i) the improvement of photosynthetic carbon assimilation of C3 plants by transgenic engineering using non-C4 genes, and (ii) the overexpression of individual or multiple C4 cycle photosynthetic genes (PEPC, PPDK, PCK, NADP-ME and NADP-MDH) in transgenic C3 plants (e.g. tobacco, potato, rice and Arabidopsis) are highlighted. Some transgenic C3 plants (e.g. tobacco, rice and Arabidopsis) overexpressing the FBP/SBPase, ictB and cytochrome c6 genes showed positive effects on photosynthetic efficiency and growth characteristics. However, over the last 28 years, efforts to overexpress individual, double or multiple C4 enzymes in C3 plants like tobacco, potato, rice, and Arabidopsis have produced mixed results that do not confirm or eliminate the possibility of improving photosynthesis of C3 plants by this approach. Finally, a prospect

  11. Insect stings to change gear for healthy plant: Improving maize drought tolerance by whitefly infestation.

    PubMed

    Park, Yong-Soon; Ryu, Choong-Min

    2016-05-03

    Since plants first appeared about 1.1 billion years ago, they have been faced with biotic and abiotic stresses in their environment. To overcome these stresses, plants developed defense strategies. Accumulating evidence suggests that the whitefly [Bemisia tabaci (Genn.)] affects the regulation of plant defenses and physiology. A recent study demonstrates that aboveground whitefly infestation positively modulates root biomass and anthocyanin pigmentation on brace roots of maize plants (Zea mays L.). In agreement with these observations, indole-3-acetic acid (IAA) and jasmonic acid (JA) contents and the expression of IAA- and JA-related genes are higher in whitefly-infested maize plants than in non-infected control plants. Interestingly, the fresh weight of whitefly-infested maize plants is approximately 20% higher than in non-infected control plants under water stress conditions. Further investigation has revealed that hydrogen peroxide (H2O2) accumulates in whitefly-infested maize plants after water stoppage. Taken together, these results suggest that activation of phytohormones- (i.e., IAA and JA) and H2O2-mediated maize signaling pathways triggered by aboveground whitefly infestation promotes drought resistance. They also provide an insight into how inter-kingdom interactions can improve drought tolerance in plants.

  12. Microbial Inoculation Improves Growth of Oil Palm Plants (Elaeis guineensis Jacq.).

    PubMed

    Om, Azlin Che; Ghazali, Amir Hamzah Ahmad; Keng, Chan Lai; Ishak, Zamzuri

    2009-12-01

    Intr