Science.gov

Sample records for actual plant conditions

  1. Conditional sterility in plants

    DOEpatents

    Meagher, Richard B.; McKinney, Elizabeth; Kim, Tehryung

    2010-02-23

    The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

  2. Establishing seasonal chronicles of actual evapotranspiration under sloping conditions

    NASA Astrophysics Data System (ADS)

    Zitouna Chebbi, R.; Prévot, L.; Jacob, F.; Voltz, M.

    2012-04-01

    Estimation of daily and seasonal actual evapotranspiration (ETa) is strongly needed for hydrological and agricultural purposes. Although the eddy covariance method is well suited for such estimation of land surface fluxes, this method suffers from limitations when establishing long time series. Missing data are often encountered, resulting from bad meteorological conditions, rejection by quality control tests, power failures… Numerous gap fill techniques have been proposed in the literature but there applicability in sloping conditions is not well known. In order to estimate ETa over long periods (agricultural cycle) on crops cultivated in sloping areas, a pluri-annual experiment was conducted in the Kamech catchment, located in North-eastern Tunisia. This Mediterranean site is characterized by a large heterogeneity in topography, soils and crops. Land surface fluxes were measured using eddy covariance systems. Measurements were collected on the two opposite sides of the Kamech V-shaped catchment, within small fields having slopes steeper than 5%. During three different years, four crops were studied: durum wheat, oat, fava bean and pasture. The topography of the catchment and the wind regime induced upslope and downslope flows over the study fields. In this study, we showed that gap filling of the turbulent fluxes (sensible and latent heat) can be obtained through linear regressions against net radiation. To account for the effect of the topography, linear regressions were calibrated by distinguishing upslope and downslope flows. This significantly improved the quality of the reconstructed data over 30 minute intervals. This gap filling technique also improved the energy balance closure at the daily time scale. As a result, seasonal chronicles of daily ETa throughout the growth cycle of the study crops in the Kamech watershed were established, thus providing useful information about the water use of annual crops in a semi-arid rainfed and hilly area.

  3. Self Actualization and Modification of Affective Self Disclosures during a Social Conditioning Interview

    ERIC Educational Resources Information Center

    Hekmat, Hamid; Theiss, Michael

    1971-01-01

    Analysis of the data indicated that the low self actualizing group had the highest rate of conditioning, while the high self actualizing individuals showed a nonsignificant gain in the rate of affective self disclosures during conditioning but were more resistant to extinction as compared to the low and the moderate groups. (Author)

  4. [Psychoactive plant species--actual list of plants prohibited in Poland].

    PubMed

    Simonienko, Katarzyna; Waszkiewicz, Napoleon; Szulc, Agata

    2013-01-01

    According to the Act on Counteracting Drug Addiction (20-th of March, 2009, Dz. U. Nr 63 poz. 520.) the list of federally prohibited plants in Poland was expanded to include 16 new species. Until that time the only illegal plant materials were cannabis, papaver, coca and most of their products. The actual list of herbal narcotics includes species which significantly influence on the central nervous system work but which are rarely described in the national literature. The plants usually come from distant places, where--among primeval cultures--are used for ritual purposes. In our civilization the plants are usually used experimentally, recreationally or to gain particular narcotic effects. The results of the consumption vary: they can be specific or less typical, imitate other substances intake, mental disorders or different pathological states. The plant active substances can interact with other medicaments, be toxic to internal organs, cause serious threat to health or even death. This article describes the sixteen plant species, which are now prohibited in Poland, their biochemical ingredients and their influence on the human organism.

  5. Plant Condition Remote Monitoring Technique

    NASA Technical Reports Server (NTRS)

    Fotedar, L. K.; Krishen, K.

    1996-01-01

    This paper summarizes the results of a radiation transfer study conducted on houseplants using controlled environmental conditions. These conditions included: (1) air and soil temperature; (2) incident and reflected radiation; and (3) soil moisture. The reflectance, transmittance, and emittance measurements were conducted in six spectral bands: microwave, red, yellow, green, violet and infrared, over a period of three years. Measurements were taken on both healthy and diseased plants. The data was collected on plants under various conditions which included: variation in plant bio-mass, diurnal variation, changes in plant pathological conditions (including changes in water content), different plant types, various disease types, and incident light wavelength or color. Analysis of this data was performed to yield an algorithm for plant disease from the remotely sensed data.

  6. Cadmium and zinc interactions and their transfer in soil-crop system under actual field conditions.

    PubMed

    Nan, Zhongren; Li, Jijun; Zhang, Jianming; Cheng, Guodong

    2002-02-21

    The transfer of Cd and Zn from calcareous soils nearby a non-ferrous mining and smelting bases to the spring wheat (Triticum aestivum L.) and corn (Zea mays L.) tissues and the interactions between the two metals concerned were investigated under actual field conditions. Samples of soils and entire crops were randomly collected during harvest time in 1998 in the Baiyin region. The soil metal contents showed that the furrows had been polluted (mean values: 3.16 mg kg(-1) for Cd; 146.78 mg kg(-1) for Zn) and the significant spatial variation of the soil contamination existed here (ranges, Cd: 0.14-19.3 mg kg(-1); Zn: 43.5-565.0 mg kg(-1)). The translocation ratios of the two metals from soil to crop parts in the region studied were relatively lower and the order of the element transfer in different plant tissues was root > stem > grain. The transfer ratio of element Cd was lower than that of element Zn. Cd and Zn uptake by the crop structures could be best described by four models (P < 0.01): linear; exponential; quadratic; and cubic. Apart from a linear relationship between the element Cd in the corn grains and soils, models were generally non-lincar. An analysis of Cd-Zn interaction mechanism led to the conclusion that the effects of the two metals were synergistic to each other under field conditions, in which increasing Cd and Zn contents in soils could increase the accumulations of Zn or Cd in the two crops.

  7. Biological carbon fixation: A study of Isochrysis sp. growth under actual coal-fired power plant's flue gas

    NASA Astrophysics Data System (ADS)

    >Liyana Yahya, Muhammad Nazry Chik, Mohd Asyraf Mohd Azmir Pang,

    2013-06-01

    Preliminary study on the growth of marine microalgae Isochrysis sp. was carried out using actual flue gas from a coal-fired power station. The species was cultured using a 2×10-L customized bubble column photobioreactor skid under specified culture conditions. With an initial culture density of 0.459 Abs (optical density at 560 nm wavelength), the species was found able to survive - observed by increases in optical densities, number of cells and weights - in the presence of actual coal-fired flue gas containing on average 4.08 % O2, 200.21 mg/m3 SO2, 212.29 mg/m3 NOx, 4.73 % CO2 and 50.72 mg/m3 CO. Results thus add value to the potential and capability of microalgae, especially for Isochrysis sp., to be the biological carbon fixer in neutralizing carbon emissions from power plants.

  8. [Method for direct generation data for formatted case report forms based on requirement for data authenticity in actual clinical conditions].

    PubMed

    Shao, Ming-Yi; Liu, Bao-Yan; He, Li-Yun; Zhang, Run-Shun

    2013-04-01

    Data authenticity is the basic requirement of clinical studies. In actual clinical conditions how to establish formatted case report forms (CRF) in line with the requirement for data authenticity is the key to ensure clinical data quality. On the basis of the characteristics of clinical data in actual clinical conditions, we determined elements for establishing formatted case report forms by comparing differences in data characteristics of CRFs in traditional clinical studies and in actual clinical conditions, and then generated formatted case report forms in line with the requirement for data authenticity in actual clinical conditions. The data of formatted CRFs generated in this study could not only meet the requirement for data authenticity of clinical studies in actual clinical conditions, but also comply with data management practices for clinical studies, thus it is deemed as a progress in technical methods.

  9. Actual versus predicted impacts of three ethanol plants on aquatic and terrestrial resources

    SciTech Connect

    Eddlemon, G.K.; Webb, J.W.; Hunsaker, D.B. Jr.; Miller, R.L.

    1993-03-15

    To help reduce US dependence on imported petroleum, Congress passed the Energy Security Act of 1980 (public Law 96-294). This legislation authorized the US Department of Energy (DOE) to promote expansion of the fuel alcohol industry through, among other measures, its Alcohol Fuels Loan Guarantee Program. Under this program, selected proposals for the conversion of plant biomass into fuel-grade ethanol would be granted loan guarantees. of 57 applications submitted for loan guarantees to build and operate ethanol fuel projects under this program, 11 were considered by DOE to have the greatest potential for satisfying DOE`s requirements and goals. In accordance with the National Environmental Policy Act (NEPA), DOE evaluated the potential impacts of proceeding with the Loan Guarantee Program in a programmatic environmental assessment (DOE 1981) that resulted in a finding of no significant impact (FANCY) (47 Federal Register 34, p. 7483). The following year, DOE conducted site-specific environmental assessments (EAs) for 10 of the proposed projects. These F-As predicted no significant environmental impacts from these projects. Eventually, three ethanol fuel projects received loan guarantees and were actually built: the Tennol Energy Company (Tennol; DOE 1982a) facility near Jasper in southeastern Tennessee; the Agrifuels Refining Corporation (Agrifuels; DOE 1985) facility near New Liberia in southern Louisiana; and the New Energy Company of Indiana (NECI; DOE 1982b) facility in South Bend, Indiana. As part of a larger retrospective examination of a wide range of environmental effects of ethanol fuel plants, we compared the actual effects of the three completed plants on aquatic and terrestrial resources with the effects predicted in the NEPA EAs several years earlier. A secondary purpose was to determine: Why were there differences, if any, between actual effects and predictions? How can assessments be improved and impacts reduced?

  10. Optimization of CCGT power plant and performance analysis using MATLAB/Simulink with actual operational data.

    PubMed

    Hasan, Naimul; Rai, Jitendra Nath; Arora, Bharat Bhushan

    2014-01-01

    In the Modern scenario, the naturally available resources for power generation are being depleted at an alarming rate; firstly due to wastage of power at consumer end, secondly due to inefficiency of various power system components. A Combined Cycle Gas Turbine (CCGT) integrates two cycles- Brayton cycle (Gas Turbine) and Rankine cycle (Steam Turbine) with the objective of increasing overall plant efficiency. This is accomplished by utilising the exhaust of Gas Turbine through a waste-heat recovery boiler to run a Steam Turbine. The efficiency of a gas turbine which ranges from 28% to 33% can hence be raised to about 60% by recovering some of the low grade thermal energy from the exhaust gas for steam turbine process. This paper is a study for the modelling of CCGT and comparing it with actual operational data. The performance model for CCGT plant was developed in MATLAB/Simulink. PMID:24936394

  11. Optimization of CCGT power plant and performance analysis using MATLAB/Simulink with actual operational data.

    PubMed

    Hasan, Naimul; Rai, Jitendra Nath; Arora, Bharat Bhushan

    2014-01-01

    In the Modern scenario, the naturally available resources for power generation are being depleted at an alarming rate; firstly due to wastage of power at consumer end, secondly due to inefficiency of various power system components. A Combined Cycle Gas Turbine (CCGT) integrates two cycles- Brayton cycle (Gas Turbine) and Rankine cycle (Steam Turbine) with the objective of increasing overall plant efficiency. This is accomplished by utilising the exhaust of Gas Turbine through a waste-heat recovery boiler to run a Steam Turbine. The efficiency of a gas turbine which ranges from 28% to 33% can hence be raised to about 60% by recovering some of the low grade thermal energy from the exhaust gas for steam turbine process. This paper is a study for the modelling of CCGT and comparing it with actual operational data. The performance model for CCGT plant was developed in MATLAB/Simulink.

  12. Emissions from heavy-duty vehicles under actual on-road driving conditions

    NASA Astrophysics Data System (ADS)

    Durbin, Thomas D.; Johnson, Kent; Miller, J. Wayne; Maldonado, Hector; Chernich, Don

    Emission measurements of five 1996-2005 heavy-duty diesel vehicles (HDDVs), representing three engine certification levels, were made using a Mobile Emissions Laboratory under actual on-road driving conditions on surface streets and highways. The results show that emissions depend on the emission component, the age/certification of vehicle/engine, as well as driving condition. For NO x emissions, there was a trend of decreasing emissions in going from older to newer model years and certification standards. Some vehicles showed a tendency toward higher NO x emissions per mile for the higher speed events (⩾55 mph) as compared to the 40 mph cruise and the other surface street driving, while others did not show large differences between different types of driving. For particulate matter (PM), the three oldest trucks had the highest emissions for surface street driving, while the two newest trucks had the highest PM emissions for highway driving. For total hydrocarbons (THC) emissions, some vehicles showed a tendency for higher emissions for the surface street segments compared to the steady-state segments, while others showed a tendency for higher emissions for the 40 mph cruise segments compared to the highway cruise segments. CO emissions under steady-state driving conditions were relatively low (1-3 g mile -1).

  13. Legacy of earthworms' engineering effects enlarges the actual effects of earthworms on plants

    NASA Astrophysics Data System (ADS)

    Mudrák, Obdřej; Frouz, Jan

    2015-04-01

    Earthworms were recognized as key factor responsible for changes from early to late successional plant communities. They incorporate organic matter into the soil and creates there persistent structures, which improves conditions for plant growth. Earthworm activity might be therefore expected to be more important in early stages of the succession, when earthworm colonization of previously earthworm free soil starts, than in the late stages of the succession, where the soil was previously modified by earthworms. However, earthworms affect plants also via other effects such as increase of nutrient availability. The relative importance of soil structure modification and other earthworm effects on plants is poorly known, despite it is important for both theoretical and applied ecology. To test the effect of earthworms (Lumbricus rubellus and Aporrectodea caliginosa) on plants we performed microcosm laboratory experiment, where earthworms were affecting early successional (Poa compressa, Medicago lupulina, and Daucus carota) and late successional (Arrhenatherum elatius, Lotus corniculatus, and Plantago laceolata) plat species in soil previously unaffected by earthworms and in soil with previous long term effect of earthworms. These soils were taken from the early and late successional monitoring sites of the Sokolov coal mining district with known history. Earthworms increased plant biomass proportionally more in late successional soil. It was mainly because they increased availability of nutrients (nitrate and potassium) and plants get higher advantage out of this in late successional soil. Earthworms increased plant biomass of both early and late successional species, but late successional species suppressed early successional species in competition. This suppression was more intensive in presence of earthworms and in late successional soil. We therefore found multiplicative effect between earthworm soil engineering activity and their other effects, which might be

  14. Cesium adsorption/desorption behavior of clay minerals considering actual contamination conditions in Fukushima

    PubMed Central

    Mukai, Hiroki; Hirose, Atsushi; Motai, Satoko; Kikuchi, Ryosuke; Tanoi, Keitaro; Nakanishi, Tomoko M.; Yaita, Tsuyoshi; Kogure, Toshihiro

    2016-01-01

    Cesium adsorption/desorption experiments for various clay minerals, considering actual contamination conditions in Fukushima, were conducted using the 137Cs radioisotope and an autoradiography using imaging plates (IPs). A 50 μl solution containing 0.185 ~ 1.85 Bq of 137Cs (10−11 ~ 10−9 molL−1 of 137Cs) was dropped onto a substrate where various mineral particles were arranged. It was found that partially-vermiculitized biotite, which is termed “weathered biotite” (WB) in this study, from Fukushima sorbed 137Cs far more than the other clay minerals (fresh biotite, illite, smectite, kaolinite, halloysite, allophane, imogolite) on the same substrate. When WB was absent on the substrate, the amount of 137Cs sorbed to the other clay minerals was considerably increased, implying that selective sorption to WB caused depletion of radiocesium in the solution and less sorption to the coexisting minerals. Cs-sorption to WB continued for about one day, whereas that to ferruginous smectite was completed within one hour. The sorbed 137Cs in WB was hardly leached with hydrochloric acid at pH 1, particularly in samples with a longer sorption time. The presence/absence of WB sorbing radiocesium is a key factor affecting the dynamics and fate of radiocesium in Fukushima. PMID:26868138

  15. [An investigation into the actual condition of the sports drink intake on children].

    PubMed

    Yamamoto, M; Amano, H; Miura, K; Nagasaka, N

    1990-01-01

    The purpose of this study was to investigate the actual condition of the sport drink intake on children. We conducted an investigation by means of questionnaires at 3 nursery schools and a day nursery in and around Hiroshima City, and using 505 answers with the comparison between 4 areas. The following results were obtained: 1) Less than 10% of the children often took sport drinks and about 70% of the children sometimes. 2) In response to the question of when taken, 40-50% of answers revealed that the drinks were taken when the children ill and 20-40% of answers were take from home. 3) In response to the question as to why children begin to take the drinks, many parents answered that they were advised by a doctor and a nurse to give their child sport drinks to prevent for dehydration, when their children were ill. This answer accounted for about 60% of the answers to this question. 4) Parents imagined that fruit drinks, carbonated beverages and beverages with lactic acid promoted tooth decay. Also the image of cariogenicity was less than 100% fruit juices, home-made juices, sport drinks, cow milks and water or tea in that order. The results suggest that parents regard sport drinks as beverages which do not promote tooth decay and give their child sport drinks frequency.

  16. Cesium adsorption/desorption behavior of clay minerals considering actual contamination conditions in Fukushima

    NASA Astrophysics Data System (ADS)

    Mukai, Hiroki; Hirose, Atsushi; Motai, Satoko; Kikuchi, Ryosuke; Tanoi, Keitaro; Nakanishi, Tomoko M.; Yaita, Tsuyoshi; Kogure, Toshihiro

    2016-02-01

    Cesium adsorption/desorption experiments for various clay minerals, considering actual contamination conditions in Fukushima, were conducted using the 137Cs radioisotope and an autoradiography using imaging plates (IPs). A 50 μl solution containing 0.185 ~ 1.85 Bq of 137Cs (10‑11 ~ 10‑9 molL‑1 of 137Cs) was dropped onto a substrate where various mineral particles were arranged. It was found that partially-vermiculitized biotite, which is termed “weathered biotite” (WB) in this study, from Fukushima sorbed 137Cs far more than the other clay minerals (fresh biotite, illite, smectite, kaolinite, halloysite, allophane, imogolite) on the same substrate. When WB was absent on the substrate, the amount of 137Cs sorbed to the other clay minerals was considerably increased, implying that selective sorption to WB caused depletion of radiocesium in the solution and less sorption to the coexisting minerals. Cs-sorption to WB continued for about one day, whereas that to ferruginous smectite was completed within one hour. The sorbed 137Cs in WB was hardly leached with hydrochloric acid at pH 1, particularly in samples with a longer sorption time. The presence/absence of WB sorbing radiocesium is a key factor affecting the dynamics and fate of radiocesium in Fukushima.

  17. Cesium adsorption/desorption behavior of clay minerals considering actual contamination conditions in Fukushima

    NASA Astrophysics Data System (ADS)

    Mukai, Hiroki; Hirose, Atsushi; Motai, Satoko; Kikuchi, Ryosuke; Tanoi, Keitaro; Nakanishi, Tomoko M.; Yaita, Tsuyoshi; Kogure, Toshihiro

    2016-02-01

    Cesium adsorption/desorption experiments for various clay minerals, considering actual contamination conditions in Fukushima, were conducted using the 137Cs radioisotope and an autoradiography using imaging plates (IPs). A 50 μl solution containing 0.185 ~ 1.85 Bq of 137Cs (10-11 ~ 10-9 molL-1 of 137Cs) was dropped onto a substrate where various mineral particles were arranged. It was found that partially-vermiculitized biotite, which is termed “weathered biotite” (WB) in this study, from Fukushima sorbed 137Cs far more than the other clay minerals (fresh biotite, illite, smectite, kaolinite, halloysite, allophane, imogolite) on the same substrate. When WB was absent on the substrate, the amount of 137Cs sorbed to the other clay minerals was considerably increased, implying that selective sorption to WB caused depletion of radiocesium in the solution and less sorption to the coexisting minerals. Cs-sorption to WB continued for about one day, whereas that to ferruginous smectite was completed within one hour. The sorbed 137Cs in WB was hardly leached with hydrochloric acid at pH 1, particularly in samples with a longer sorption time. The presence/absence of WB sorbing radiocesium is a key factor affecting the dynamics and fate of radiocesium in Fukushima.

  18. Cesium adsorption/desorption behavior of clay minerals considering actual contamination conditions in Fukushima.

    PubMed

    Mukai, Hiroki; Hirose, Atsushi; Motai, Satoko; Kikuchi, Ryosuke; Tanoi, Keitaro; Nakanishi, Tomoko M; Yaita, Tsuyoshi; Kogure, Toshihiro

    2016-01-01

    Cesium adsorption/desorption experiments for various clay minerals, considering actual contamination conditions in Fukushima, were conducted using the (137)Cs radioisotope and an autoradiography using imaging plates (IPs). A 50 μl solution containing 0.185 ~ 1.85 Bq of (137)Cs (10(-11) ~ 10(-9 )molL(-1) of (137)Cs) was dropped onto a substrate where various mineral particles were arranged. It was found that partially-vermiculitized biotite, which is termed "weathered biotite" (WB) in this study, from Fukushima sorbed (137)Cs far more than the other clay minerals (fresh biotite, illite, smectite, kaolinite, halloysite, allophane, imogolite) on the same substrate. When WB was absent on the substrate, the amount of (137)Cs sorbed to the other clay minerals was considerably increased, implying that selective sorption to WB caused depletion of radiocesium in the solution and less sorption to the coexisting minerals. Cs-sorption to WB continued for about one day, whereas that to ferruginous smectite was completed within one hour. The sorbed (137)Cs in WB was hardly leached with hydrochloric acid at pH 1, particularly in samples with a longer sorption time. The presence/absence of WB sorbing radiocesium is a key factor affecting the dynamics and fate of radiocesium in Fukushima.

  19. AI-related BMD variation in actual practice conditions: A prospective cohort study.

    PubMed

    Rodríguez-Sanz, María; Prieto-Alhambra, Daniel; Servitja, Sonia; Garcia-Giralt, Natalia; Garrigos, Laia; Rodriguez-Morera, Jaime; Albanell, Joan; Martínez-García, Maria; González, Iria; Diez-Perez, Adolfo; Tusquets, Ignasi; Nogués, Xavier

    2016-04-01

    The aim of the study was to evaluate the progression of bone mineral density (BMD) during 3 years of aromatase inhibitors (AI) therapy in actual practice conditions. This prospective, clinical cohort study of Barcelona-Aromatase induced Bone Loss in Early breast cancer (B-ABLE) assessed BMD changes during 3 years of AI treatment in women with breast cancer. Patients with osteoporosis (T score < -2.5 or T score ≤ -2.0) and a major risk factor and/or prevalent fragility fractures were treated with oral bisphosphonates (BPs). Of 685 women recruited, 179 (26.1%) received BP treatment. By the third year of AI therapy, this group exhibited increased BMD in the lumbar spine (LS; 2.59%) and femoral neck (FN; 2.50%), although the increase was significant only within the first year (LS: 1.99% and FN: 2.04%). Despite BP therapy, however, approximately 15% of these patients lost more than 3% of their baseline bone mass. At 3 years, patients without BP experienced BMD decreases in the LS (-3.10%) and FN (-2.79%). In this group, BMD changes occurred during the first (LS: -1.33% and FN: -1.25%), second (LS: -1.19% and FN: -0.82%), and third (LS: -0.57% and FN: -0.65%) years of AI treatment. Increased BMD (>3%) was observed in just 7.6% and 10.8% of these patients at the LS and FN, respectively. Our data confirm a clinically relevant bone loss associated with AI therapy amongst nonusers of preventative BPs. We further report on the importance of BMD monitoring as well as calcium and 25-hydroxy vitamin D supplementation in these patients. PMID:26911377

  20. Separating habitat invasibility by alien plants from the actual level of invasion.

    PubMed

    Chytrý, Milan; Jarosik, Vojtech; Pysek, Petr; Hájek, Ondrej; Knollová, Ilona; Tichý, Lubomír; Danihelka, Jií

    2008-06-01

    Habitats vary considerably in the level of invasion (number or proportion of alien plant species they contain), which depends on local habitat properties, propagule pressure, and climate. To determine the invasibility (susceptibility to invasions) of different habitats, it is necessary to factor out the effects of any confounding variables such as propagule pressure and climate on the level of invasion. We used 20 468 vegetation plots from 32 habitats in the Czech Republic to compare the invasibility of different habitats. Using regression trees, the proportion of alien plants, including archaeophytes (prehistoric to medieval invaders) and neophytes (recent invaders), was related to variables representing habitat properties, propagule pressure, and climate. The propagule pressure was expressed as the proportion of surrounding urban and industrial or agricultural land, human population density, distance from a river, and history of human colonization in the region. Urban and industrial land use had a positive effect on the proportion of both archaeophytes and neophytes. Agricultural land use, higher population density, and longer history of human impact positively affected the proportion of archaeophytes. Disturbed human-made habitats with herbaceous vegetation were most invaded by both groups of aliens. Neophytes were also relatively common in disturbed woody vegetation, such as broad-leaved plantations, forest clearings, and riverine scrub. These habitats also had the highest proportion of aliens after removing the effect of propagule pressure and climate, indicating that they are not only the most invaded, but also most invasible. These habitats experience recurrent disturbances and are rich, at least temporarily, in available nutrients, which supports the hypothesis that fluctuating resources are the major cause of habitat invasibility. The least invaded habitats were mires and alpine-subalpine grasslands and scrub. After removing the effect of propagule

  1. Divergence of actual and reference evapotranspiration observations for irrigated sugarcane with windy tropical conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are frequently used to estimate actual ET. However, equations for calculating reference ET have not been well validated in more humid environments. We measured ET (ETEC) using Eddy Covariance (EC) towers a...

  2. Comparative analysis of operational forecasts versus actual weather conditions in airline flight planning, volume 2

    NASA Technical Reports Server (NTRS)

    Keitz, J. F.

    1982-01-01

    The impact of more timely and accurate weather data on airline flight planning with the emphasis on fuel savings is studied. This volume of the report discusses the results of Task 2 of the four major tasks included in the study. Task 2 compares various catagories of flight plans and flight tracking data produced by a simulation system developed for the Federal Aviation Administrations by SRI International. (Flight tracking data simulate actual flight tracks of all aircraft operating at a given time and provide for rerouting of flights as necessary to resolve traffic conflicts.) The comparisons of flight plans on the forecast to flight plans on the verifying analysis confirm Task 1 findings that wind speeds are generally underestimated. Comparisons involving flight tracking data indicate that actual fuel burn is always higher than planned, in either direction, and even when the same weather data set is used. Since the flight tracking model output results in more diversions than is known to be the case, it was concluded that there is an error in the flight tracking algorithm.

  3. Novel in-situ focus monitor technology in attenuated PSM under actual illumination condition

    NASA Astrophysics Data System (ADS)

    Izuha, Kyoko; Asano, Masafumi; Fujisawa, Tadahito; Inoue, Soichi

    2003-06-01

    A focus monitor technology for attenuated PSM under annular illumination has been developed as an in-line quality control. The focus monitor pattern on a reticle employs a pair of grouped lozenge-shaped opening patterns in attenuated phase shifting region. Since the phase shifting angles of the light passing through the first and second opening patterns are 90 degrees and 180 degrees, respectively, the best focus position for the first pattern shifts to that for the second pattern. The subtraction of the length of the patterns is a linear function of the actual focal position printed on the wafer. Therefore, the effective focal position can be extracted by measuring the subtraction of the measured length. A high resolution of 10-nm defocus could be achieved by this technique.

  4. Rheological investigation of body cream and body lotion in actual application conditions

    NASA Astrophysics Data System (ADS)

    Kwak, Min-Sun; Ahn, Hye-Jin; Song, Ki-Won

    2015-08-01

    The objective of the present study is to systematically evaluate and compare the rheological behaviors of body cream and body lotion in actual usage situations. Using a strain-controlled rheometer, the steady shear flow properties of commercially available body cream and body lotion were measured over a wide range of shear rates, and the linear viscoelastic properties of these two materials in small amplitude oscillatory shear flow fields were measured over a broad range of angular frequencies. The temperature dependency of the linear viscoelastic behaviors was additionally investigated over a temperature range most relevant to usual human life. The main findings obtained from this study are summarized as follows: (1) Body cream and body lotion exhibit a finite magnitude of yield stress. This feature is directly related to the primary (initial) skin feel that consumers usually experience during actual usage. (2) Body cream and body lotion exhibit a pronounced shear-thinning behavior. This feature is closely connected with the spreadability when cosmetics are applied onto the human skin. (3) The linear viscoelastic behaviors of body cream and body lotion are dominated by an elastic nature. These solid-like properties become a criterion to assess the selfstorage stability of cosmetic products. (4) A modified form of the Cox-Merz rule provides a good ability to predict the relationship between steady shear flow and dynamic viscoelastic properties for body cream and body lotion. (5) The storage modulus and loss modulus of body cream show a qualitatively similar tendency to gradually decrease with an increase in temperature. In the case of body lotion, with an increase in temperature, the storage modulus is progressively decreased while the loss modulus is slightly increased and then decreased. This information gives us a criterion to judge how the characteristics of cosmetic products are changed by the usual human environments.

  5. Comparative analysis of operational forecasts versus actual weather conditions in airline flight planning, volume 3

    NASA Technical Reports Server (NTRS)

    Keitz, J. F.

    1982-01-01

    The impact of more timely and accurate weather data on airline flight planning with the emphasis on fuel savings is studied. This volume of the report discusses the results of Task 3 of the four major tasks included in the study. Task 3 compares flight plans developed on the Suitland forecast with actual data observed by the aircraft (and averaged over 10 degree segments). The results show that the average difference between the forecast and observed wind speed is 9 kts. without considering direction, and the average difference in the component of the forecast wind parallel to the direction of the observed wind is 13 kts. - both indicating that the Suitland forecast underestimates the wind speeds. The Root Mean Square (RMS) vector error is 30.1 kts. The average absolute difference in direction between the forecast and observed wind is 26 degrees and the temperature difference is 3 degree Centigrade. These results indicate that the forecast model as well as the verifying analysis used to develop comparison flight plans in Tasks 1 and 2 is a limiting factor and that the average potential fuel savings or penalty are up to 3.6 percent depending on the direction of flight.

  6. Comparative analysis of operational forecasts versus actual weather conditions in airline flight planning: Summary report

    NASA Technical Reports Server (NTRS)

    Keitz, J. F.

    1982-01-01

    The impact of more timely and accurate weather data on airline flight planning with the emphasis on fuel savings is studied. This summary report discusses the results of each of the four major tasks of the study. Task 1 compared airline flight plans based on operational forecasts to plans based on the verifying analyses and found that average fuel savings of 1.2 to 2.5 percent are possible with improved forecasts. Task 2 consisted of similar comparisons but used a model developed for the FAA by SRI International that simulated the impact of ATc diversions on the flight plans. While parts of Task 2 confirm the Task I findings, inconsistency with other data and the known impact of ATC suggests that other Task 2 findings are the result of errors in the model. Task 3 compares segment weather data from operational flight plans with the weather actually observed by the aircraft and finds the average error could result in fuel burn penalties (or savings) of up to 3.6 percent for the average 8747 flight. In Task 4 an in-depth analysis of the weather forecast for the 33 days included in the study finds that significant errors exist on 15 days. Wind speeds in the area of maximum winds are underestimated by 20 to 50 kts., a finding confirmed in the other three tasks.

  7. Divergence of actual and reference evapotranspiration observations for irrigated sugarcane with windy tropical conditions

    NASA Astrophysics Data System (ADS)

    Anderson, R. G.; Wang, D.; Tirado-Corbalá, R.; Zhang, H.; Ayars, J. E.

    2015-01-01

    Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are frequently used to estimate actual ET. However, equations for calculating reference ET have not been well validated in tropical environments. We measured ET (ETEC) using eddy covariance (EC) towers at two irrigated sugarcane fields on the leeward (dry) side of Maui, Hawaii, USA in contrasting climates. We calculated reference ET at the fields using the short (ET0) and tall (ETr) vegetation versions of the American Society for Civil Engineers (ASCE) equation. The ASCE equations were compared to the Priestley-Taylor ET (ETPT) and ETEC. Reference ET from the ASCE approaches exceeded ETEC during the mid-period (when vegetation coefficients suggest ETEC should exceed reference ET). At the windier tower site, cumulative ETr exceeded ETEC by 854 mm over the course of the mid-period (267 days). At the less windy site, mid-period ETr still exceeded ETEC, but the difference was smaller (443 mm). At both sites, ETPT approximated mid-period ETEC more closely than the ASCE equations ((ETPT-ETEC) < 170 mm). Analysis of applied water and precipitation, soil moisture, leaf stomatal resistance, and canopy cover suggest that the lower observed ETEC was not the result of water stress or reduced vegetation cover. Use of a custom-calibrated bulk canopy resistance improved the reference ET estimate and reduced seasonal ET discrepancy relative to ETPT and ETEC in the less windy field and had mixed performance in the windier field. These divergences suggest that modifications to reference ET equations may be warranted in some tropical regions.

  8. Global test of the conductor for Tore Supra under actual working conditions

    SciTech Connect

    Aymar, R.; Deck, C.; Genevey, P.; Lefevre, F.; Leloup, C.; Meuris, C.; Palanque, S.; Sagniez, A.; Turck, B.

    1981-09-01

    In a plasma current disruption event, the superconducting winding of the toroidal coils of a Tokomak must suffer severe conditions of magnetic field variations without losing superconductivity. An experimental setup has been built to simulate conditions which would eventually occur in ''Tore Supra'' and study the behavior of the designed conductor. A sample of this conductor is subjected simultaneously to a dc transverse magnetic field up to 9.5 T, a transport current up to 2200 amp and two pulsed field components: one parallel to the conductor length, up to 1 T and one perpendicular, up to 0.35 T. The time constant of these pulsed field components is adjustable from 8 to 150 ms. They can be applied independently or simultaneously. The experimental arrangement is able to provide quantitative limits for safe operations of ''Tore Supra''. 7 refs.

  9. Determination of Shelf Life for Butter and Cheese Products in Actual and Accelerated Conditions

    PubMed Central

    Lim, Kwang-Sei; Yang, Cheul-Young

    2014-01-01

    The aim of this study was to estimate the shelf life of butter and cheese products, with shelf life being a guide used to determine the storage period of food before deterioration. Butter and cheese samples stored at 10℃ and 15℃ had a shelf life of 221 d, while those stored at 25℃ and 35℃ had a shelf life of 109 d. Quality changes, including total cell count, coliform counts, Listeria monocytogenes counts, acid value, moisture content, pH, acidity and overall sensory evaluation, were monitored. In order to pass the overall sensory evaluation, a quality score of 5 points on a 9-point scale was required. For other quality criteria, legal quality limits were established based on the “Process Criteria and Ingredient Standard of Livestock Products” by the Animal, Plant and Fisheries Quarantine and Inspection Agency (Republic of Korea). The nonlegal quality limit was estimated by regression analysis between non-quality criteria (y) and overall sensory evaluation (x). The shelf life was estimated based on the number of days that the product passed the quality limit of the quality criteria. The shelf life of samples stored at 10℃, 15℃, 25℃ and 35℃ was 21.94, 17.18, 6.10 and 0.58 mon, respectively, for butter and 10.81, 9.47, 4.64 and 0.20 mon, respectively, for cheese. PMID:26760945

  10. Determination of Shelf Life for Butter and Cheese Products in Actual and Accelerated Conditions.

    PubMed

    Park, Jung-Min; Shin, Jin-Ho; Bak, Da-Jeong; Kim, Na-Kyeong; Lim, Kwang-Sei; Yang, Cheul-Young; Kim, Jin-Man

    2014-01-01

    The aim of this study was to estimate the shelf life of butter and cheese products, with shelf life being a guide used to determine the storage period of food before deterioration. Butter and cheese samples stored at 10℃ and 15℃ had a shelf life of 221 d, while those stored at 25℃ and 35℃ had a shelf life of 109 d. Quality changes, including total cell count, coliform counts, Listeria monocytogenes counts, acid value, moisture content, pH, acidity and overall sensory evaluation, were monitored. In order to pass the overall sensory evaluation, a quality score of 5 points on a 9-point scale was required. For other quality criteria, legal quality limits were established based on the "Process Criteria and Ingredient Standard of Livestock Products" by the Animal, Plant and Fisheries Quarantine and Inspection Agency (Republic of Korea). The nonlegal quality limit was estimated by regression analysis between non-quality criteria (y) and overall sensory evaluation (x). The shelf life was estimated based on the number of days that the product passed the quality limit of the quality criteria. The shelf life of samples stored at 10℃, 15℃, 25℃ and 35℃ was 21.94, 17.18, 6.10 and 0.58 mon, respectively, for butter and 10.81, 9.47, 4.64 and 0.20 mon, respectively, for cheese.

  11. Wind Plant Capacity Credit Variations: A Comparison of Results Using Multiyear Actual and Simulated Wind-Speed Data

    SciTech Connect

    Milligan, M.

    1997-06-01

    Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term patters. This report calculates the range of capacity credit measures based on 13 years of actual wind-speed data. The results are compared to those obtained with synthetic data sets that are based on one year of data. Although the use of synthetic data sets is a considerable improvement over single-estimate techniques, this report finds that the actual inter-annual variation in capacity credit is still understated by the synthetic data technique.

  12. Wind plant capacity credit variations: A comparison of results using multiyear actual and simulated wind-speed data

    SciTech Connect

    Milligan, M.R.

    1997-12-31

    Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term patterns. This paper calculates the range of capacity credit measures based on 13 years of actual wind-speed data. The results are compared to those obtained with synthetic data sets that are based on one year of data. Although the use of synthetic data sets is a considerable improvement over single-estimate techniques, this paper finds that the actual inter-annual variation in capacity credit is still understated by the synthetic data technique.

  13. Wind Plant Capacity Credit Variations: A Comparison of Results Using Multiyear Actual and Simulated Wind-Speed Data

    SciTech Connect

    Milligan, Michael

    1997-06-01

    Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term patterns. This paper calculates the range of capacity credit measures based on 13 years of actual wind-speed data. The results are compared to those obtained with synthetic data sets that are based on one year of data. Although the use of synthetic data sets is a considerable improvement over single-estimate techniques, this paper finds that the actual inter- annual variation in capacity credit is still understated by the synthetic data technique.

  14. [Characteristics of working conditions at metallurgy-related plants].

    PubMed

    Egorova, A M

    2008-01-01

    Working conditions at more versus less advanced technology steel plants of the Volgograd Region are analyzed. The working conditions at the less advanced technology plants are referred to as a very high occupational risk. It is necessary to work out measures to lower the poor impact of microclimate, dust, noise, to improve illumination, and to regulate labor at steel plants.

  15. Low persistence of a monocarpic invasive plant in historical sites biases our perception of its actual distribution

    PubMed Central

    Pergl, Jan; Pyšek, Petr; Perglová, Irena; Jarošík, Vojtěch; Procheş, Şerban

    2012-01-01

    Aim As accurate and up-to-date distribution data for plant species are rarely available, cumulative records over long periods of time are frequently used for mapping distributions, without taking into account that species do not persist in their historical localities forever. However, persistence is highly relevant in changing modern landscapes, especially for invasive species that dynamically spread in unstable human-made habitats. We studied how an invasive species, Heracleum mantegazzianum, persists at sites once colonized and how its ability to persist affects its distribution. Location The Czech Republic. Methods We visited 521 localities of H. mantegazzianum occurrence reported in the literature and herbaria to determine whether the species still occurs at these sites. By using G-tests and classification trees, we explored the roles of various factors affecting its persistence at a site. Results Of the total number of 521 historical sites at which the species has occurred since the end of the 19th century, it persists at only 124 (23.8%). The persistence rate differs with respect to habitat type and is highest in meadows and forest margins. Analysis using classification trees indicated that the factors that best explain persistence are: type of habitat (with meadow and forest margins over-represented); urbanity (with a higher persistence outside urban areas); proximity to the place of the species’ introduction into the country; metapopulation connectivity; and distance to the nearest neighbouring population. Main conclusions The use of cumulative historical records as a measure of species distribution, which is common in invasion literature, can seriously overestimate the actual distribution of alien plant species with low persistence. In the case of alien species such as H. mantegazzanium, which is non-clonal and reproduces only by seed, estimates of distribution and spread based on historical data are informative about potentially suitable habitat but may

  16. Discrimination of rapeseed and weeds under actual field conditions based on principal component analysis and artificial neural network by VIS/NIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Min; Bao, Yidan; He, Yong

    2007-11-01

    The study documented successful discrimination between five weed species and rapeseed plants under actual field conditions using visible and near infrared (Vis/NIR) spectroscopy. A hybrid recognition model, BP artificial neural networks (BP-ANN) combined with principal component analysis (PCA), had been established for discrimination of weeds in rapeseed field. Spectra tests were performed on the rapeseed and five-weed species canopy of 180 samples in the field using a spectrophotometer (325-1075 nm). 6 optimal PCs were selected as the input of BP neural networks to build the prediction model. Rapeseed samples were marked as 1, while the five weed species marked as 2, 3, 4, 5, 6, which were used as output set of BP-ANN. 120 samples were randomly selected as the training set, and the remainder as prediction set. It showed excellent predictions with the correlation value of 0.9745, and the relative standard deviation (RSD) was under 5% thus 100% of prediction accuracy was achieved. The results are promising for further work in real-time identification of weed patches in rapeseed fields for precision weed management.

  17. Actual and potential use of population viability analyses in recovery of plant species listed under the US endangered species act.

    PubMed

    Zeigler, Sara L; Che-Castaldo, Judy P; Neel, Maile C

    2013-12-01

    Use of population viability analyses (PVAs) in endangered species recovery planning has been met with both support and criticism. Previous reviews promote use of PVA for setting scientifically based, measurable, and objective recovery criteria and recommend improvements to increase the framework's utility. However, others have questioned the value of PVA models for setting recovery criteria and assert that PVAs are more appropriate for understanding relative trade-offs between alternative management actions. We reviewed 258 final recovery plans for 642 plants listed under the U.S. Endangered Species Act to determine the number of plans that used or recommended PVA in recovery planning. We also reviewed 223 publications that describe plant PVAs to assess how these models were designed and whether those designs reflected previous recommendations for improvement of PVAs. Twenty-four percent of listed species had recovery plans that used or recommended PVA. In publications, the typical model was a matrix population model parameterized with ≤5 years of demographic data that did not consider stochasticity, genetics, density dependence, seed banks, vegetative reproduction, dormancy, threats, or management strategies. Population growth rates for different populations of the same species or for the same population at different points in time were often statistically different or varied by >10%. Therefore, PVAs parameterized with underlying vital rates that vary to this degree may not accurately predict recovery objectives across a species' entire distribution or over longer time scales. We assert that PVA, although an important tool as part of an adaptive-management program, can help to determine quantitative recovery criteria only if more long-term data sets that capture spatiotemporal variability in vital rates become available. Lacking this, there is a strong need for viable and comprehensive methods for determining quantitative, science-based recovery criteria for

  18. Biodegradation of polyacrylamide by anaerobic digestion under mesophilic condition and its performance in actual dewatered sludge system.

    PubMed

    Dai, Xiaohu; Luo, Fan; Yi, Jing; He, Qunbiao; Dong, Bin

    2014-02-01

    Polyacrylamide (PAM) used in sludge dewatering widely exists in high-solid anaerobic digestion. Degradation of polyacrylamide accompanied with accumulation of its toxic monomer is important to disposition of biogas residues. The potential of anaerobic digestion activity in microbial utilization of PAM was investigated in this study. The results indicated that the utilization rate of PAM (as nitrogen source) was influenced by accumulation of ammonia, while cumulative removal of amide group was accorded with zeroth order reaction in actual dewatered system. The adjoining amide group can combined into ether group after biodegradation. PAM can be broken down in different position of its carbon chain backbone. In actual sludge system, the hydrolytic PAM was liable to combined tyrosine-rich protein to form colloid complex, and then consumed as carbon source to form monomer when easily degradable organics were exhausted. The accumulation of acrylamide was leveled off ultimately, accompanied with the yield of methane.

  19. Strigolactones as mediators of plant growth responses to environmental conditions.

    PubMed

    Koltai, Hinanit; Kapulnik, Yoram

    2011-01-01

    Strigolactones (SLs) have been recently identified as a new group of plant hormones or their derivatives thereof, shown to play a role in plant development. Evolutionary forces have driven the development of mechanisms in plants that allow adaptive adjustments to a variety of different habitats by employing plasticity in shoot and root growth and development. The ability of SLs to regulate both shoot and root development suggests a role in the plant's response to its growth environment. To play this role, SL pathways need to be responsive to plant growth conditions, and affect plant growth toward increased adaptive adjustment. Here, the effects of SLs on shoot and root development are presented, and possible feedback loops between SLs and two environmental cues, light and nutrient status, are discussed; these might suggest a role for SLs in plants' adaptive adjustment to growth conditions.

  20. [The Red Cross System for War Relief during the Second World War and Actual Conditions of Its Efforts in Burma].

    PubMed

    Kawahara, Yukari

    2015-12-01

    This paper aims to show the system for relief provided by the Japanese Red Cross relief units during the Second World War, as well as the actual activities of sixteen of its relief units dispatched to Burma. The Red Cross wartime relief efforts involved using personnel and funding prepared beforehand to provide aid to those injured in war, regardless of their status as ally or enemy. Thus they were able to receive support from the army in order to ensure safety and provide supplies. Nurses dispatched to Burma took care of many patients who suffered from malnutrition and physical injuries amidst the outbreak of infectious diseases typical of tropical areas, without sufficient replacement members. Base hospitals not meant for the front lines also came under attack, and the nurses' lives were thus in mortal danger. Of the 374 original members, 29 died or went missing in action.

  1. An eye-tracking investigation into readers' sensitivity to actual versus expected utility in the comprehension of conditionals.

    PubMed

    Haigh, Matthew; Ferguson, Heather J; Stewart, Andrew J

    2014-01-01

    The successful comprehension of a utility conditional (i.e., an "if p, then q" statement where p and/or q is valued by one or more agents) requires the construction of a mental representation of the situation described by that conditional and integration of this representation with prior context. In an eye-tracking experiment, we examined the time course of integrating conditional utility information into the broader discourse model. Specifically, the experiment determined whether readers were sensitive, during rapid heuristic processing, to the congruency between the utility of the consequent clause of a conditional (positive or negative) and a reader's subjective expectations based on prior context. On a number of eye-tracking measures we found that readers were sensitive to conditional utility-conditionals for which the consequent utility mismatched the utility that would be anticipated on the basis of prior context resulted in processing disruption. Crucially, this sensitivity emerged on measures that are accepted to indicate early processing within the language comprehension system and suggests that the evaluation of a conditional's utility informs the early stages of conditional processing.

  2. The development of a test system for investigating the performances of personal aerosol samplers under actual workplace conditions.

    PubMed

    Botham, R A; Hughson, G W; Vincent, J H; Mark, D

    1991-10-01

    The performances of new "total" aerosol samplers for use in workplaces are required to match the inhalability criteria as contained in the latest recommendations of the International Standards Organization (ISO) and the American Conference of Governmental Industrial Hygienists (ACGIH). In the past, practical evaluations have been carried out under idealized conditions in wind tunnels, and there is now the need to extend these to more realistic workplace conditions. This paper describes a new test system that was designed and built for this purpose. It consisted of a life-size mannequin mounted on a trolley so that it can be taken to and wheeled around in workplaces. The mannequin itself incorporated a robotic arm so that, under joystick control, it can be made to simulate a range of worker movements, orientations, and attitudes. An electronically controlled, compact breathing machine provided a range of typical breathing parameters for the mannequin. The pump also provided air movement for a number of personal samplers that were mounted on the torso of the mannequin and tested in that position. Sampler performance should be assessed by comparing directly the aerosol collected by the sampler with that inhaled by the mannequin (and collected on filters inside the head).

  3. Development of plant condition measurement - The Jimah Model

    NASA Astrophysics Data System (ADS)

    Evans, Roy F.; Syuhaimi, Mohd; Mazli, Mohammad; Kamarudin, Nurliyana; Maniza Othman, Faiz

    2012-05-01

    The Jimah Model is an information management model. The model has been designed to facilitate analysis of machine condition by integrating diagnostic data with quantitative and qualitative information. The model treats data as a single strand of information - metaphorically a 'genome' of data. The 'Genome' is structured to be representative of plant function and identifies the condition of selected components (or genes) in each machine. To date in industry, computer aided work processes used with traditional industrial practices, have been unable to consistently deliver a standard of information suitable for holistic evaluation of machine condition and change. Significantly the reengineered site strategies necessary for implementation of this "data genome concept" have resulted in enhanced knowledge and management of plant condition. In large plant with high initial equipment cost and subsequent high maintenance costs, accurate measurement of major component condition becomes central to whole of life management and replacement decisions. A case study following implementation of the model at a major power station site in Malaysia (Jimah) shows that modeling of plant condition and wear (in real time) can be made a practical reality.

  4. Plant Neighbour Identity Matters to Belowground Interactions under Controlled Conditions

    PubMed Central

    Armas, Cristina; Pugnaire, Francisco Ignacio

    2011-01-01

    Background Root competition is an almost ubiquitous feature of plant communities with profound effects on their structure and composition. Far beyond the traditional view that plants interact mainly through resource depletion (exploitation competition), roots are known to be able to interact with their environment using a large variety of mechanisms that may inhibit or enhance access of other roots to the resource or affect plant growth (contest interactions). However, an extensive analysis on how these contest root interactions may affect species interaction abilities is almost lacking. Methodology/Principal Findings In a common garden experiment with ten perennial plant species we forced pairs of plants of the same or different species to overlap their roots and analyzed how belowground contest interactions affected plant performance, biomass allocation patterns, and competitive abilities under abundant resource supply. Our results showed that net interaction outcome ranged from negative to positive, affecting total plant mass and allocation patterns. A species could be a strong competitor against one species, weaker against another one, and even facilitator to a third species. This leads to sets of species where competitive hierarchies may be clear but also to groups where such rankings are not, suggesting that intransitive root interactions may be crucial for species coexistence. Conclusions/Significance The outcome of belowground contest interactions is strongly dependent on neighbours' identity. In natural plant communities this conditional outcome may hypothetically help species to interact in non-hierarchical and intransitive networks, which in turn might promote coexistence. PMID:22114696

  5. Plant Growth and Morphogenesis under Different Gravity Conditions: Relevance to Plant Life in Space.

    PubMed

    Hoson, Takayuki

    2014-05-16

    The growth and morphogenesis of plants are entirely dependent on the gravitational acceleration of earth. Under microgravity conditions in space, these processes are greatly modified. Recent space experiments, in combination with ground-based studies, have shown that elongation growth is stimulated and lateral expansion suppressed in various shoot organs and roots under microgravity conditions. Plant organs also show automorphogenesis in space, which consists of altered growth direction and spontaneous curvature in the dorsiventral (back and front) directions. Changes in cell wall properties are responsible for these modifications of growth and morphogenesis under microgravity conditions. Plants live in space with interesting new sizes and forms.

  6. Temperature rise in plant reproductive organs under low gravity conditions

    NASA Astrophysics Data System (ADS)

    Kitaya, Yoshiaki; Hirai, Hiroaki

    Excess temperature rise in plant reproductive organs such as anthers and stigmas could cause fertility impediments and thus produce sterile seeds without adequately controlled environ-ments in closed plant growth facilities. There is a possibility such a situation could occur in Bioregenerative Life Support Systems under microgravity conditions in space because there will be little natural convective or thermal mixing. This study was conducted to determine the thermal situation of the plant reproductive organs as affected by gravity levels of 0.01, 1.0 and 2.0 g for 20 seconds each during parabolic airplane flights and to make an estimation of temperature increases in the reproductive organs in closed plant growth facilities under mi-crogravity in space. Thermal images of reproductive organs of rice and tomato were captured using infrared thermography at an air temperature of 31.5C, a relative humidity of 11

  7. Improvements in and actual performance of the Plant Experiment Unit onboard Kibo, the Japanese experiment module on the international space station

    NASA Astrophysics Data System (ADS)

    Yano, Sachiko; Kasahara, Haruo; Masuda, Daisuke; Tanigaki, Fumiaki; Shimazu, Toru; Suzuki, Hiromi; Karahara, Ichirou; Soga, Kouichi; Hoson, Takayuki; Tayama, Ichiro; Tsuchiya, Yoshikazu; Kamisaka, Seiichiro

    2013-03-01

    In 2004, Japan Aerospace Exploration Agency developed the engineered model of the Plant Experiment Unit and the Cell Biology Experiment Facility. The Plant Experiment Unit was designed to be installed in the Cell Biology Experiment Facility and to support the seed-to-seed life cycle experiment of Arabidopsis plants in space in the project named Space Seed. Ground-based experiments to test the Plant Experiment Unit showed that the unit needed further improvement of a system to control the water content of a seedbed using an infrared moisture analyzer and that it was difficult to keep the relative humidity inside the Plant Experiment Unit between 70 and 80% because the Cell Biology Experiment Facility had neither a ventilation system nor a dehumidifying system. Therefore, excess moisture inside the Cell Biology Experiment Facility was removed with desiccant bags containing calcium chloride. Eight flight models of the Plant Experiment Unit in which dry Arabidopsis seeds were fixed to the seedbed with gum arabic were launched to the International Space Station in the space shuttle STS-128 (17A) on August 28, 2009. Plant Experiment Unit were installed in the Cell Biology Experiment Facility with desiccant boxes, and then the Space Seed experiment was started in the Japanese Experiment Module, named Kibo, which was part of the International Space Station, on September 10, 2009 by watering the seedbed and terminated 2 months later on November 11, 2009. On April 19, 2010, the Arabidopsis plants harvested in Kibo were retrieved and brought back to Earth by the space shuttle mission STS-131 (19A). The present paper describes the Space Seed experiment with particular reference to the development of the Plant Experiment Unit and its actual performance in Kibo onboard the International Space Station. Downlinked images from Kibo showed that the seeds had started germinating 3 days after the initial watering. The plants continued growing, producing rosette leaves, inflorescence

  8. Biomechanical responses of aquatic plants to aerial conditions

    PubMed Central

    Hamann, Elena; Puijalon, Sara

    2013-01-01

    Background and Aims Wetlands are impacted by changes in hydrological regimes that can lead to periods of low water levels. During these periods, aquatic plants experience a drastic change in the mechanical conditions that they encounter, from low gravitational and tensile hydrodynamic forces when exposed to flow under aquatic conditions, to high gravitational and bending forces under terrestrial conditions. The objective of this study was to test the capacity of aquatic plants to produce self-supporting growth forms when growing under aerial conditions by assessing their resistance to terrestrial mechanical conditions and the associated morpho-anatomical changes. Methods Plastic responses to aerial conditions were assessed by sampling Berula erecta, Hippuris vulgaris, Juncus articulatus, Lythrum salicaria, Mentha aquatica, Myosotis scorpioides, Nuphar lutea and Sparganium emersum under submerged and emergent conditions. The cross-sectional area and dry matter content (DMC) were measured in the plant organs that bear the mechanical forces, and their biomechanical properties in tension and bending were assessed. Key Results All of the species except for two had significantly higher stiffness in bending and thus an increased resistance to terrestrial mechanical conditions when growing under emergent conditions. This response was determined either by an increased allocation to strengthening tissues and thus a higher DMC, or by an increased cross-sectional area. These morpho-anatomical changes also resulted in increased strength and stiffness in tension. Conclusions The capacity of the studied species to colonize this fluctuating environment can be accounted for by a high degree of phenotypic plasticity in response to emersion. Further investigation is however needed to disentangle the finer mechanisms behind these responses (e.g. allometric relations, tissue make-up), their costs and adaptive value. PMID:24187030

  9. Breed effects and heterosis in advanced generations of composite populations on actual weight, adjusted weight, hip height, and condition score of beef cows.

    PubMed

    Gregory, K E; Cundiff, L V; Koch, R M

    1992-06-01

    Heterosis effects were evaluated in three composite populations in F1, F2, and F3 generations separately and combined in 1-yr-old and from 2- through greater than or equal to 7-yr-old beef cows. Traits included actual weight, weight adjusted to a common condition score, hip height, and condition score. Breed effects were evaluated in the nine parental breeds (Red Poll [R], Hereford [H], Angus [A], Limousin [L], Braunvieh [B], Pinzgauer [P], Gelbvieh [G], Simmental [S], and Charolais [C]) that contributed to the three composite populations (MARC I = 1/4 B, 1/4 C, 1/4 L, 1/8 H, 1/8 A; MARC II = 1/4 G, 1/4 S, 1/4 H, 1/4 A; and MARC III = 1/4 R, 1/4 P, 1/4 H, 1/4 A). Breed group (parental breed and composite) effects were significant for all traits analyzed. The effects of heterosis were generally important (P less than .05) for all traits in F1, F2, and F3 generations separately and combined in the three composite populations. Generally, the magnitude of heterosis observed at 1 yr of age did not differ from that observed in cows from 2 through greater than or equal to 7 yr old. Adjusting weight to a common condition score resulted in an average reduction of heterosis effects on actual weight by approximately one-fourth. Thus, approximately one-fourth of the effects of heterosis on weight result from heterosis effects on condition score. Generally, retained heterosis in the F3 generation of either 1-yr-old or from 2-through greater than or equal to 7-yr-old cows of the three composite populations did not differ (P greater than .05) from expectation based on retained heterozygosity for the traits analyzed. These results support the hypothesis that heterosis for weight, hip height, and condition score of cows of these age classes is the result of dominance effects of genes.

  10. Physiological Response of Plants to Temporary Changes in Gravity Conditions

    NASA Astrophysics Data System (ADS)

    Pandolfi, Camilla; Mugnai, Sergio; Masi, Elisa; Azzarello, Elisa; Voigt, Boris; Baluska, Frantisek; Volkmann, Dieter; Mancuso, Stefano

    Gravity is the main factor that influences the direction of growth of plant organs, and has also a direct effect on the plant metabolism. When an organ, mainly roots, is turned by between 0 (vertical) and 90 (horizontal), the change of orientation is perceived by its organs producing the so-called gravitropic reaction, which involves a strong metabolic response. In order to study these reaction in real microgravity conditions, some experiments have been set up during six ESA parabolic flight campaign. Oxygen concentration in the solution, in which roots of Zea mays were placed, have been constantly monitored during normal, hyper-and microgravity conditions. An evident burst in oxygen fluxes started just 2.0 0.5 s after the imposition of microgravity conditions. No significant changes were noticed neither in normal nor in hyper-gravity conditions. These measurements were done using oxymeters, that revealed the onset of long lasting oxygen bursts appearing only during microgravity. Although the chemical nature of these oxygen bursts is still unknown, they may implicate a strong generation of reactive oxygen species as they exactly match the microgravity situation. Thus, our data strongly sug-gest that the sensing mechanism is not related to a general mechano-stress, which was imposed also during hypergravity, but is very specific of the microgravity situation. Moreover, it is well-known that stress rapidly induces reactive oxygen bursts which are associated with oxygen influx and reactive oxygen efflux from stressed plant tissues. Accordingly, our data indicate that microgravity represents a stress situation for plants, especially for root apices, and these bursts, probably ROS, are initiating and integrating adaptive responses of plant roots which resemble other unrelated stress situations. To validate this hypothesis we added to our ex-perimental set-up two very sensitive selective microelectrodes for H2 O2 and NO, and, even if the parabolic flights are not

  11. Strategies of Plant Water Use under Stochastic Hydrologic Conditions

    NASA Astrophysics Data System (ADS)

    Vico, G.; Albertson, J.; Katul, G.; Porporato, A.; Ridolfi, L.; Rodriguez-Iturbe, I.

    2003-12-01

    Recent papers on ecohydrology have discussed how a "tragedy of the commons" effect, in which the competitive evolutionary outcome is lower than the ecosystem optimum (e.g. maximum productivity), may arise in plants because of a trade-off between resource-uptake rate and resource efficiency. Using simple deterministic and stochastic models of soil water balance and ecosystem response to water stress, we investigate how efficient water-use strategies can evolve and persist against more aggressive but less efficient strategies of water use. Survival of plants and coexistence of different species is discussed in relation to their drought tolerance and water use efficiency, under conditions of temporal and spatial environmental variability

  12. Methodology and Process for Condition Assessment at Existing Hydropower Plants

    SciTech Connect

    Zhang, Qin Fen; Smith, Brennan T; Cones, Marvin; March, Patrick; Dham, Rajesh; Spray, Michael

    2012-01-01

    Hydropower Advancement Project was initiated by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy to develop and implement a systematic process with a standard methodology to identify the opportunities of performance improvement at existing hydropower facilities and to predict and trend the overall condition and improvement opportunity within the U.S. hydropower fleet. The concept of performance for the HAP focuses on water use efficiency how well a plant or individual unit converts potential energy to electrical energy over a long-term averaging period of a year or more. The performance improvement involves not only optimization of plant dispatch and scheduling but also enhancement of efficiency and availability through advanced technology and asset upgrades, and thus requires inspection and condition assessment for equipment, control system, and other generating assets. This paper discusses the standard methodology and process for condition assessment of approximately 50 nationwide facilities, including sampling techniques to ensure valid expansion of the 50 assessment results to the entire hydropower fleet. The application and refining process and the results from three demonstration assessments are also presented in this paper.

  13. Actual conditions of work, fatigue and sleep in non-employed, home-based female information technology workers with preschool children.

    PubMed

    Sasaki, Tsukasa; Matsumoto, Shun

    2005-01-01

    We conducted a study on time budget and fatigue feelings over a two-month period of 12 non-employed, home-based female workers using computers (mean age 35.2 yr). All of them had at least one preschool child. The actual amount of work done by these women and the related effects on the fatigue feelings and sleep were investigated. The results showed that the work done was characterized by involving many night hours, irrespective of the day of the week. The degree of subjective fatigue was not dependent on the number of hours worked, but affected by the time at which the work of the day was completed. This tendency was notable after one o'clock in the morning when the work was completed. Those who followed such a work pattern took daytime naps, although a quality of the subsequent nighttime sleep taken might be poor. They took a nap around 14:00 but not around 19:00. The sleep strategies were thus shown to be affected by home-based work. A need is suggested to support these workers in adjusting work time distribution and taking sleep patterns adapted to individual conditions. PMID:15732317

  14. Actual Condition of Paddy Field Levee Maintenance by Various Farm Households including Large-scale Farming in the Developed Land Renting Area

    NASA Astrophysics Data System (ADS)

    Sakata, Yasuyo

    The survey of interview, resource acquisition, photographic operation, and questionnaire were carried out in the “n” Community in the “y” District in Hakusan City in Ishikawa Prefecture to investigate the actual condition of paddy field levee maintenance in the area where land-renting market was proceeding, large-scale farming was dominant, and the problems of geographically scattered farm-land existed. In the study zone, 1) an agricultural production legal person rent-cultivated some of the paddy fields and maintained the levees, 2) another agricultural production legal person rent-cultivated some of the soy bean fields for crop changeover and land owners maintained the levees. The results indicated that sufficient maintenance was executed on the levees of the paddy fields cultivated by the agricultural production legal person, the soy bean fields for crop changeover, and the paddy fields cultivated by the land owners. Each reason is considered to be the managerial strategy, the economic incentive, the mutual monitoring and cross-regulatory mechanism, etc.

  15. Stem sap flow in plants under low gravity conditions

    NASA Astrophysics Data System (ADS)

    Tokuda, Ayako; Hirai, Hiroaki; Kitaya, Yoshiaki

    2016-07-01

    A study was conducted to obtain a fundamental knowledge for plant functions in bio-regenerative life support systems in space. Stem sap flow in plants is important indicators for water transport from roots to atmosphere through leaves. In this study, stem sap flow in sweetpotato was assessed at gravity levels from 0.01 to 2 g for about 20 seconds each during parabolic airplane flights. Stem sap flow was monitored with a heat balance method in which heat generated with a tiny heater installed in the stem was transferred upstream and downstream by conduction and upstream by convection with the sap flow through xylems of the vascular tissue. Thermal images of stem surfaces near heated points were captured using infrared thermography and the internal heat convection corresponding to the sap flow was analyzed. In results, the sap flow in stems was suppressed more at lower gravity levels without forced air circulation. No suppression of the stem sap flow was observed with forced air circulation. Suppressed sap flow in stems would be caused by suppression of transpiration in leaves and would cause restriction of water and nutrient uptake in roots. The forced air movement is essential to culture healthy plants at a high growth rate under low gravity conditions in space.

  16. Human Impacts to Coastal Ecosystems in Puerto Rico (HICE-PR): Actual Condition of Coral Reefs Associated with the Guanica and Manati Watersheds in Puerto Rico

    NASA Astrophysics Data System (ADS)

    Torres-Perez, J. L.; Barreto, M.; Guild, L. S.; Ortiz, J.; Setegn, S. G.; Ramos-Scharron, C. E.; Armstrong, R.; Santiago, L.

    2015-12-01

    For several decades Puerto Rico's coastal and marine ecosystems (CMEs), particularly coral reefs, have suffered the effects of anthropogenic stresses associated to population growth and varying land use. Here we present an overview of the first year of findings of a NASA-funded project that studies human impacts in two priority watersheds (Manatí and Guánica). The project includes remote sensing analysis and hydrological, ecological and socio-economic modeling to provide a multi-decadal assessment of change of CMEs. The project's main goal is to evaluate the impacts of land use/land cover changes on the quality and extent of CMEs in priority watersheds in the north and south coasts of Puerto Rico. This project will include imagery from Landsat 8 to assess coastal ecosystems extent. Habitat and species distribution maps will be created by incorporating field and remotely-sensed data into an Ecological Niche Factor Analysis. The social component will allow us to study the valuation of specific CMEs attributes from the stakeholder's point of view. Field data was collected through a series of phototransects at the main reefs associated with these two priority watersheds. A preliminary assessment shows a range in coral cover from 0.2-30% depending on the site (Guánica) whereas apparently healthy corals dominate the reef in the north coast (Manatí). Reefs on the southwest coast of PR (Guánica) show an apparent shift from hard corals to a more algae and soft corals dominance after decades of anthropogenic impacts (sedimentation, eutrophication, mechanical damage through poorly supervised recreational activities, etc.). Additionally preliminary results from land cover/land use changes analyses show dynamic historical shoreline changes in beaches located west of the Manatí river mouth and a degradation of water quality in Guánica possibly being one of the main factors affecting the actual condition of its CMEs.

  17. Microbiological condition of beef mechanically tenderized at a packing plant.

    PubMed

    Gill, C O; McGinnis, J C; Rahn, K; Young, D; Lee, N; Barbut, S

    2005-04-01

    When striploins were mechanically tenderized at a beef packing plant, the log total numbers of aerobes, coliforms, staphylococci/listerias and Escherichia coli recovered from surfaces before or after tenderizing were about 2.8, 2.0, 0.6 and 0.3 log cfu 25 cm(-2), respectively. The numbers of those organisms recovered from the deep tissues of the tenderized meat were about 2.0, 1.5 and 1.2 log cfu 25 g(-1) and none, respectively. The aerobes recovered from the deep tissues were unexpectedly numerous in view of the small numbers of bacteria on meat surfaces. That suggests deep tissue contamination was affected by factors other than the numbers on meat surfaces. After cooking tenderized beef to medium rare or well done conditions, with maximum temperatures at steak centres of ⩽65.4 or ⩽73.4 °C, respectively, aerobes were recovered from only 2 of 25 samples cooked to each condition, at numbers of one or two per sample. This indicates that such cooking can ensure the microbiological safety of mechanically tenderized beef prepared under controlled conditions.

  18. Plant protection under conditions of radioactive contamination of agricultural lands

    SciTech Connect

    Filipas, A.S.; Oulianenko, L.N.; Pimenov, E.P.

    1995-12-31

    Increasing influence of anthropogenic contaminants as well as substantiated risk of the action of ionizing radiation on agroecosystems suggest the necessity of studying both the state of separate components of cenosis and search for methods on retention of ecosystem stability as a whole. In this case it should be taken into account that by retention of resistance of living organisms to the action of stress agents not only genetically conditioned potential but induction of protective reactions at the expense of ecogene action is of deciding significance as well. Protection of agricultural plants on the territories subjected to radioactive contamination resulting from the ChNPP accident brings attention of research works to a series of problems, the main one being the minimization of pesticide use by the total ecologization of technological processes, in plant growing. But an ordinary discontinuance of conducting protective chemical measures leads to growth in the number of harmful organisms in crop sowings and as a consequence an increase of crop loss and decrease of its quality. It is possible to solve this problem by introduction of measures increasing the resistance of agricultural plants to the action of unfavorable factors of environment. Application of biologically active substances (BAS) of natural and synthetic nature for incrustation of seeds fits into these methods. For the territories with increased content of radionuclides and especially by their rehabilitation the methods of preventive treatments directed to retarding the development of harmful organisms in crop sowings and excluding subsequent technological operations on chemical protection of sowings takes on special significance as it is directly connected with the problem of radiation burden on workers of agroindustrial complex.

  19. Thermostability of plants in various light conditions of cultivation

    NASA Astrophysics Data System (ADS)

    Zavorueva, Elena

    2004-12-01

    At various levels of PHAR with the help of measurement of parameters of a slow induction of chlorophyll fluorescence at 682 and 734 nm in light culture conditions the thermostable estimation of cenosises of plants of wheat and radish in reply to action of the raise and damaging temperatures of air (35°C 20 hours, 45°C 7 hours) is carried out. Without dependence from a level of light exposure, the exposition of cenosises at 35°C did not result in irreversible changes of the photosynthetic device of plants. The minimal damage of cenosises of wheat and radish at influence of temperature of 45°C is observed at 150W/m2 of PHAR, and maximal - at intensities, close to a level of a compensatory point of photosynthesis of cenosises (50-70 W/m2 PHAR at a temperature of air of 24°C). The index of viability is most sensitive parameter in comparison with other parameters determined by a method of a slow induction of fluorescence at 682 and 734 nm. The character of its change in reply to action of the stress-factor coincides with changes of intensity of photosynthesis researched of cenosises.

  20. RESPONSE OF WETLAND PLANT SPECIES TO HYDROLOGIC CONDITIONS

    EPA Science Inventory

    Understanding hydrologic requirements of native and introduced species is critical to sustaining native plant communities in wetlands of disturbed landscapes. We examined plant assemblages and 31 species from emergent wetlands in an urbanizing area of the Pacific Northwest, USA,...

  1. RESPONSE OF WETLAND PLANT SPECIES TO HYDROLOGIC CONDITIONS

    EPA Science Inventory

    Understanding hydrologic requirements of native and introduced species is critical to sustaining native plant communities in wetlands of disturbed landscapes. We examined plant assemblages and 31 species from emergent wetlands in an urbanizing area of the Pacific Northwest, USA, ...

  2. Uptake of human pharmaceuticals by plants grown under hydroponic conditions.

    PubMed

    Herklotz, Patrick A; Gurung, Prakash; Vanden Heuvel, Brian; Kinney, Chad A

    2010-03-01

    Cabbage (Brassica rapa var. pekinensis) and Wisconsin Fast Plants (Brassica rapa) were chosen for a proof of concept study to determine the potential uptake and accumulation of human pharmaceuticals by plants. These plants were grown hydroponically under high-pressure sodium lamps in one of two groups including a control and test group exposed to pharmaceuticals. The control plants were irrigated with a recirculating Hoagland's nutrient solution while the test plants were irrigated with a Hoagland's nutrient solution fortified with the pharmaceuticals carbamazepine, salbutamol, sulfamethoxazole, and trimethoprim at 232.5 microg L(-1). When plants reached maturity, nine entire plants of each species were separated into components such as roots, leaves, stems, and seedpods where applicable. An analytical method for quantifying pharmaceuticals and personal care products was developed using pressurized liquid extraction and liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS) in positive and negative ion modes using single ion monitoring. The method detection limits ranged from 3.13 ng g(-1) to 29.78 ng g(-1) with recoveries ranging from 66.83% to 113.62% from plant matrices. All four of the pharmaceuticals were detected in the roots and leaves of the cabbage. The maximum wet weight concentrations of the pharmaceuticals were detected in the root structure of the cabbage plants at 98.87 ng g(-1) carbamazepine, 114.72 ng g(-1) salbutamol, 138.26 ng g(-1) sulfamethoxazole, and 91.33 ng g(-1) trimethoprim. Carbamazepine and salbutamol were detected in the seedpods of the Wisconsin Fast Plants while all four of the pharmaceuticals were detected in the leaf/stem/root of the Wisconsin Fast Plants. Phloroglucinol staining of root cross-sections was used to verify the existence of an intact endodermis, suggesting that pharmaceuticals found in the leaf and seedpods of the plants were transported symplastically. PMID:20096438

  3. Uptake of human pharmaceuticals by plants grown under hydroponic conditions.

    PubMed

    Herklotz, Patrick A; Gurung, Prakash; Vanden Heuvel, Brian; Kinney, Chad A

    2010-03-01

    Cabbage (Brassica rapa var. pekinensis) and Wisconsin Fast Plants (Brassica rapa) were chosen for a proof of concept study to determine the potential uptake and accumulation of human pharmaceuticals by plants. These plants were grown hydroponically under high-pressure sodium lamps in one of two groups including a control and test group exposed to pharmaceuticals. The control plants were irrigated with a recirculating Hoagland's nutrient solution while the test plants were irrigated with a Hoagland's nutrient solution fortified with the pharmaceuticals carbamazepine, salbutamol, sulfamethoxazole, and trimethoprim at 232.5 microg L(-1). When plants reached maturity, nine entire plants of each species were separated into components such as roots, leaves, stems, and seedpods where applicable. An analytical method for quantifying pharmaceuticals and personal care products was developed using pressurized liquid extraction and liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS) in positive and negative ion modes using single ion monitoring. The method detection limits ranged from 3.13 ng g(-1) to 29.78 ng g(-1) with recoveries ranging from 66.83% to 113.62% from plant matrices. All four of the pharmaceuticals were detected in the roots and leaves of the cabbage. The maximum wet weight concentrations of the pharmaceuticals were detected in the root structure of the cabbage plants at 98.87 ng g(-1) carbamazepine, 114.72 ng g(-1) salbutamol, 138.26 ng g(-1) sulfamethoxazole, and 91.33 ng g(-1) trimethoprim. Carbamazepine and salbutamol were detected in the seedpods of the Wisconsin Fast Plants while all four of the pharmaceuticals were detected in the leaf/stem/root of the Wisconsin Fast Plants. Phloroglucinol staining of root cross-sections was used to verify the existence of an intact endodermis, suggesting that pharmaceuticals found in the leaf and seedpods of the plants were transported symplastically.

  4. Screening of novel plants for biogas production in northern conditions.

    PubMed

    Seppälä, Mari; Laine, Antti; Rintala, Jukka

    2013-07-01

    The objective of this study was to screen nine annual or perennial novel plants for biogas production cultivated in years 2007-2010 in Finland. The most promising novel plants for biogas production were found to be brown knapweed, giant goldenrod and Japanese millet producing 14-27 t total solids/ha and 4000-6100 Nm(3)CH4/ha. The specific methane yields of all studied plants varied from 170 to 381 Nm(3)CH4/t volatile solids (VS), depending on harvest time and plant species. Co-digestion of brown knapweed with cow manure in continuously stirred tank reactor was investigated and the highest methane yield was 254 NL CH4/kg VS, when the share of brown knapweed was 50% in the feed VS (organic loading rate (OLR) 2 kg VS/m(3)/d). The cultivation managements and sustainability of novel plants for biogas production have to be investigated. PMID:23669072

  5. Actual Condition Evaluation of Cogeneration System in an Urbanized Hotel, and Study of the Optimal Operation to Minimize the CO2 Emission

    NASA Astrophysics Data System (ADS)

    Katsuta, Masafumi; Kaneko, Akira; Yamamoto, Toru

    Recently, there is an important subject to reduce of the CO2 emission discharged from a building. A cogeneration system (CGS) is one of the effective facilities to reduce of the CO2 emission, but prudent consideration is required in design and operation. Because it is necessary to be matching electric demand and heat demand in order to obtain the high efficiency. In this paper, it is evaluated the power generation efficiency and heat recovery one of CGS in the actual urbanized hotel as measurement result. In addition, the optimal operation analysis is carried out in order to minimize CO2 emission in the present facility.

  6. Wind power plants in the weather conditions of Northern Finland

    NASA Astrophysics Data System (ADS)

    Bohmeke, Georg

    Lappland's fells and highlands feature a notable wind power potential due to special meteorological circumstances. The wind power plants for these sites must be equipped with special means against icing and low temperatures. Icing events monitored on a small test machine are described and compared with general load assumptions. Different means of ice detection and ice removal from rotor blades are presented. Low temperature and anti-icing requirements for wind power plant components and operation control are discussed.

  7. Sensitivity and optimization analyses of the ``ACOGAS`` gas conditioning plant

    SciTech Connect

    Ochoa, D.; Cardenas, A.R.

    1995-11-01

    ACOGAS is a gas dew point control plant (water and hydrocarbons), operated by Lagoven S.A., a subsidiary of Petroleos de Venezuela S.A. (PDVSA). The ACOGAS plant located in Jusepin, Eastern Venezuela, produces stabilized condensate from an inlet gas stream which is a mixture of different gravity gases obtained by separation and compression from various oil production fields in the area. Sensitivity and optimization analyses of the plant and the stabilizer tower were carried out to evaluate the effects of: plant capacity reductions during shutdowns of some unspared systems of the plant; composition changes from original design basis; segregation of the lean gas currents from the inlet gas stream, reducing total flow but increasing GPM (C{sub 3}{sup +}) content; and incorporating condensate from the upstream compression processes in the inlet gas stream. It is shown that significant increases of stabilized condensate production could be obtained, while maintaining the quality for the condensate and lean residual gas within specifications, by various low cost modifications to the upstream processes and the stabilizer tower. Additionally, a change of the stabilizer tower valves could lower the minimum acceptable inlet flow, thereby increasing flexibility during shutdowns and low feed gas flows.

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

    PubMed

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

    2007-01-01

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

  9. Plant mitochondria under a variety of temperature stress conditions.

    PubMed

    Rurek, Michał

    2014-11-01

    The biogenesis of plant mitochondria is a multistep process that depends on a concerted expression of mitochondrial and nuclear genes. The balance between different steps of this process, embracing various fluctuations in mitochondrial transcriptome and proteome, may be affected by diverse temperature treatments. A plethora of genes with altered expression during the acting of these stimuli were identified and their expression characterized, including those encoding for classical components of energy dissipating system. Selected aspects of current interest, regarding the functioning of plant mitochondria under cold and heat stresses, are highlighted.

  10. Automated Diagnosis Of Conditions In A Plant-Growth Chamber

    NASA Technical Reports Server (NTRS)

    Clinger, Barry R.; Damiano, Alfred L.

    1995-01-01

    Biomass Production Chamber Operations Assistant software and hardware constitute expert system that diagnoses mechanical failures in controlled-environment hydroponic plant-growth chamber and recommends corrective actions to be taken by technicians. Subjects of continuing research directed toward development of highly automated closed life-support systems aboard spacecraft to process animal (including human) and plant wastes into food and oxygen. Uses Microsoft Windows interface to give technicians intuitive, efficient access to critical data. In diagnostic mode, system prompts technician for information. When expert system has enough information, it generates recovery plan.

  11. Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The aim of this study was to evaluate effects of PGPR (Plant Growth Promoting Rhizobacteria) isolated from rainforest on different plants under limited nitrogen conditions. Methods and Results: Bacterial isolates from a Peruvian rainforest soil were screened for plant growth promoting effects...

  12. Nutrient Considerations for Plants Grown Under Space Flight Conditions

    NASA Technical Reports Server (NTRS)

    Levine, Howard G.; Krikorian, Abraham D.

    2006-01-01

    We present here results on the analysis of 100 mL medium samples extracted from sterilized foam (Smithers-Oasis, Kent OH) used to support the growth of both dicotyledonous (Haplopappus gracilis, n=75) and monocotyledonous (Hemerocallis cv Autumn Blaze, n=25) aseptic plants in NASA's Plant Growth Unit (PGU) during the 5-day CHROMEX-01 Space Shuttle flight (March 1989, STS-29). At recovery, the medium remaining within each of the five floral foam blocks (for both the space flight and ground control experiments) was extracted under vacuum, filtered and subjected to elemental analyses. Concentration levels of some elements remained the same, while some decreased and others increased. A unique aspect of this experiment was that all plants were either aseptic tissue culture generated plantlets or sterile seedling clones, and the design of the PGU facilitated the maintenance of asepsis throughout the mission (confirmed by postflight microbial sampling). This permitted the elimination of microbial considerations in the interpretation of the data. The significance of these findings for growing plants in altered gravity environments are discussed.

  13. 77 FR 24228 - Condition Monitoring Techniques for Electric Cables Used in Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... COMMISSION Condition Monitoring Techniques for Electric Cables Used in Nuclear Power Plants AGENCY: Nuclear... Techniques for Electric Cables Used in Nuclear Power Plants.'' This guide describes techniques that the staff of the NRC considers acceptable for condition monitoring of electric cables for nuclear power...

  14. Experiment 8: Environmental Conditions in the ASTROCULTURE(trademark) Plant Chamber During the USML-2 Mission

    NASA Technical Reports Server (NTRS)

    Bula, R. J.; Zhou, Weijia; Yetka, R. A.; Draeger, N. A.

    1998-01-01

    Conducting plant research to assess the impact of microgravity on plant growth and development requires a plant chamber that has the capability to control other environmental parameters involved in plant growth and development. The environmental control in a space-based plant chamber must be equivalent to that available in such facilities used for terrestrial plant research. Additionally, plants are very sensitive to a number of atmospheric gaseous materials. Thus, the atmosphere of a plant chamber must be isolated from the space vehicle atmosphere, and the plant growth unit should have the capability to remove any such deleterious materials that may impact plant growth and development. The Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison, has developed a totally enclosed controlled environment plant growth unit. The flight unit was used to support the ASTROCULTURE(TM) experiment conducted during the USML-2 mission. The experiment had two major objectives: 1) Provide further validation of the flight unit to control the experiment-defined environmental parameters in the plant chamber, and 2) support a plant experiment to assess the capability of potato plant material to produce tubers in microgravity. This paper describes the temperature, humidity, and carbon dioxide conditions of the plant chamber during the mission, from launch to landing. Another paper will present the plant response data.

  15. [Role of micro-organisms in adapting plants to environmental stress conditions].

    PubMed

    Hirt, Heribert

    2012-01-01

    Due to their sessile nature, plants have always been confronted to various abiotic and biotic stresses in their immediate environment. As a consequence, the survival of plants depended on their ability to adjust rapidly their physiology, development and growth to escape or mitigate the impacts of stress. All plants are known to perceive and respond to stress signals such as drought, heat, salinity, attacks by herbivores and pathogens. Some biochemical processes are common to all plant stress responses including the production of certain stress proteins and metabolites, as well as the modification of the reactive oxygen species (ROS) metabolism. Although there has been extensive research in the plant stress response field, it is not yet known which factors are responsible for conferring to some plant species the capacity to colonize extreme habitats. Although considerable progress has been made in our understanding of plant stress physiology, the contribution of the plant-associated microbial community in the soil, commonly called the rhizosphere, has only recently received enhanced attention. Recent studies showed that some plant species in natural habitats require microbial associations for stress tolerance and survival. Since plants have colonized land, they have evolved mechanisms to respond to changing environmental conditions and settle in extreme habitats. Although many plants lack the adaptive capability to adapt to stress conditions, the ability of a variety of plants to adapt to stress conditions appears to depend on the association with microbes, raising a number of questions: can all plants improve stress tolerance when associated with their appropriate microbial partners? Did we miss identifying the right partners for a given plant species or variety? What distinguishes the microbes and plants that are adapted to extreme environmental conditions from those living in temperate zones? Answers to these questions are likely to revolutionize plant biology

  16. Paradox of plant growth promotion potential of rhizobacteria and their actual promotion effect on growth of barley (Hordeum vulgare L.) under salt stress.

    PubMed

    Cardinale, Massimiliano; Ratering, Stefan; Suarez, Christian; Zapata Montoya, Ana Maria; Geissler-Plaum, Rita; Schnell, Sylvia

    2015-12-01

    From the rhizosphere of two salt tolerant plant species, Hordeum secalinum and Plantago winteri growing in a naturally salt meadow, 100 strains were isolation on enrichment media for various plant growth-promoting (PGP) functions (ACC deaminase activity, auxin synthesis, calcium phosphate mobilization and nitrogen fixation). Based on the taxonomic affiliation of the isolated bacteria and their enrichment medium 22 isolates were selected to test their growth promotion effect on the crop barley (Hordeum vulgare) under salt stress in pot experiment. In parallel the isolates were characterized in pure culture for their plant growth-promoting activities. Surprisingly the best promotors did not display a promising set of PGP activities. Isolates with multiple PGP-activities in pure culture like Microbacterium natoriense strain E38 and Pseudomonas brassicacearum strain E8 did not promote plant growth. The most effective isolate was strain E108 identified as Curtobacterium flaccumfaciens, which increased barley growth up to 300%. In pure culture strain E108 showed only two out of six plant growth promoting activities and would have been neglected. Our results highlight that screening based on pure culture assays may not be suitable for recognition of best plant growth promotion candidates and could preclude the detection of both new PGPR and new plant promotion mechanisms. PMID:26640049

  17. Paradox of plant growth promotion potential of rhizobacteria and their actual promotion effect on growth of barley (Hordeum vulgare L.) under salt stress.

    PubMed

    Cardinale, Massimiliano; Ratering, Stefan; Suarez, Christian; Zapata Montoya, Ana Maria; Geissler-Plaum, Rita; Schnell, Sylvia

    2015-12-01

    From the rhizosphere of two salt tolerant plant species, Hordeum secalinum and Plantago winteri growing in a naturally salt meadow, 100 strains were isolation on enrichment media for various plant growth-promoting (PGP) functions (ACC deaminase activity, auxin synthesis, calcium phosphate mobilization and nitrogen fixation). Based on the taxonomic affiliation of the isolated bacteria and their enrichment medium 22 isolates were selected to test their growth promotion effect on the crop barley (Hordeum vulgare) under salt stress in pot experiment. In parallel the isolates were characterized in pure culture for their plant growth-promoting activities. Surprisingly the best promotors did not display a promising set of PGP activities. Isolates with multiple PGP-activities in pure culture like Microbacterium natoriense strain E38 and Pseudomonas brassicacearum strain E8 did not promote plant growth. The most effective isolate was strain E108 identified as Curtobacterium flaccumfaciens, which increased barley growth up to 300%. In pure culture strain E108 showed only two out of six plant growth promoting activities and would have been neglected. Our results highlight that screening based on pure culture assays may not be suitable for recognition of best plant growth promotion candidates and could preclude the detection of both new PGPR and new plant promotion mechanisms.

  18. Carbon dioxide exchange of lettuce plants under hypobaric conditions.

    PubMed

    Corey, K A; Bates, M E; Adams, S L

    1996-01-01

    Growth of plants in a Controlled Ecological Life Support System (CELSS) may involve the use of hypobaric pressures enabling lower mass requirements for atmospheres and possible enhancement of crop productivity. A controlled environment plant growth chamber with hypobaric capability designed and built at Ames Research Center was used to determine if reduced pressures influence the rates of photosynthesis (Ps) and dark respiration (DR) of hydroponically grown lettuce plants. The chamber, referred to as a plant volatiles chamber (PVC), has a growing area of about 0.2 m2, a total gas volume of about 0.7 m3, and a leak rate at 50 kPa of <0.1%/day. When the pressure in the chamber was reduced from ambient to 51 kPa, the rate of net Ps increased by 25% and the rate of DR decreased by 40%. The rate of Ps increased linearly with decreasing pressure. There was a greater effect of reduced pressure at 41 Pa CO2 than at 81 Pa CO2. This is consistent with reports showing greater inhibition of photorespiration (Pr) in reduced O2 at low CO2 concentrations. When the partial pressure of O2 was held constant but the total pressure was varied between 51 and 101 kPa, the rate of CO2 uptake was nearly constant, suggesting that low pressure enhancement of Ps may be mainly attributable to lowered partial pressure of O2 and the accompanying reduction in Pr. The effects of lowered partial pressure of O2 on Ps and DR could result in substantial increases in the rates of biomass production, enabling rapid throughput of crops or allowing flexibility in the use of mass and energy resources for a CELSS. PMID:11538809

  19. Carbon dioxide exchange of lettuce plants under hypobaric conditions

    NASA Astrophysics Data System (ADS)

    Corey, K. A.; Bates, M. E.; Adams, S. L.

    1996-01-01

    Growth of plants in a Controlled Ecological Life Support System (CELSS) may involve the use of hypobaric pressures enabling lower mass requirements for atmospheres and possible enhancement of crop productivity. A controlled environment plant growth chamber with hypobaric capability designed and built at Ames Research Center was used to determine if reduced pressures influence the rates of photosynthesis (Ps) and dark respiration (DR) of hydroponically grown lettuce plants. The chamber, referred to as a plant volatiles chamber (PVC), has a growing area of about 0.2 m^2, a total gas volume of about 0.7 m^3, and a leak rate at 50 kPa of < 0.1%/day. When the pressure in the chamber was reduced from ambient to 51 kPa, the rate of net Ps increased by 25% and the rate of DR decreased by 40%. The rate of Ps increased linearly with decreasing pressure. There was a greater effect of reduced pressure at 41 Pa CO_2 than at 81 Pa CO_2. This is consistent with reports showing greater inhibition of photorespiration (Pr) in reduced O_2 at low CO_2 concentrations. When the partial pressure of O_2 was held constant but the total pressure was varied between 51 and 101 kPa, the rate of CO_2 uptake was nearly constant, suggesting that low pressure enhancement of Ps may be mainly attributable to lowered partial pressure of O_2 and the accompanying reduction in Pr. The effects of lowered partial pressure of O_2 on Ps and DR could result in substantial increases in the rates of biomass production, enabling rapid throughput of crops or allowing flexibility in the use of mass and energy resources for a CELSS.

  20. Carbon dioxide exchange of lettuce plants under hypobaric conditions.

    PubMed

    Corey, K A; Bates, M E; Adams, S L

    1996-01-01

    Growth of plants in a Controlled Ecological Life Support System (CELSS) may involve the use of hypobaric pressures enabling lower mass requirements for atmospheres and possible enhancement of crop productivity. A controlled environment plant growth chamber with hypobaric capability designed and built at Ames Research Center was used to determine if reduced pressures influence the rates of photosynthesis (Ps) and dark respiration (DR) of hydroponically grown lettuce plants. The chamber, referred to as a plant volatiles chamber (PVC), has a growing area of about 0.2 m2, a total gas volume of about 0.7 m3, and a leak rate at 50 kPa of <0.1%/day. When the pressure in the chamber was reduced from ambient to 51 kPa, the rate of net Ps increased by 25% and the rate of DR decreased by 40%. The rate of Ps increased linearly with decreasing pressure. There was a greater effect of reduced pressure at 41 Pa CO2 than at 81 Pa CO2. This is consistent with reports showing greater inhibition of photorespiration (Pr) in reduced O2 at low CO2 concentrations. When the partial pressure of O2 was held constant but the total pressure was varied between 51 and 101 kPa, the rate of CO2 uptake was nearly constant, suggesting that low pressure enhancement of Ps may be mainly attributable to lowered partial pressure of O2 and the accompanying reduction in Pr. The effects of lowered partial pressure of O2 on Ps and DR could result in substantial increases in the rates of biomass production, enabling rapid throughput of crops or allowing flexibility in the use of mass and energy resources for a CELSS.

  1. Carbon dioxide exchange of lettuce plants under hypobaric conditions

    NASA Technical Reports Server (NTRS)

    Corey, K. A.; Bates, M. E.; Adams, S. L.; MacElroy, R. D. (Principal Investigator)

    1996-01-01

    Growth of plants in a Controlled Ecological Life Support System (CELSS) may involve the use of hypobaric pressures enabling lower mass requirements for atmospheres and possible enhancement of crop productivity. A controlled environment plant growth chamber with hypobaric capability designed and built at Ames Research Center was used to determine if reduced pressures influence the rates of photosynthesis (Ps) and dark respiration (DR) of hydroponically grown lettuce plants. The chamber, referred to as a plant volatiles chamber (PVC), has a growing area of about 0.2 m2, a total gas volume of about 0.7 m3, and a leak rate at 50 kPa of <0.1%/day. When the pressure in the chamber was reduced from ambient to 51 kPa, the rate of net Ps increased by 25% and the rate of DR decreased by 40%. The rate of Ps increased linearly with decreasing pressure. There was a greater effect of reduced pressure at 41 Pa CO2 than at 81 Pa CO2. This is consistent with reports showing greater inhibition of photorespiration (Pr) in reduced O2 at low CO2 concentrations. When the partial pressure of O2 was held constant but the total pressure was varied between 51 and 101 kPa, the rate of CO2 uptake was nearly constant, suggesting that low pressure enhancement of Ps may be mainly attributable to lowered partial pressure of O2 and the accompanying reduction in Pr. The effects of lowered partial pressure of O2 on Ps and DR could result in substantial increases in the rates of biomass production, enabling rapid throughput of crops or allowing flexibility in the use of mass and energy resources for a CELSS.

  2. Optimization of plant mineral nutrition under growth-limiting conditions in a lunar greenhouse

    NASA Astrophysics Data System (ADS)

    Zaets, I.; Voznyuk, T.; Kovalchuk, M.; Rogutskyy, I.; Lukashov, D.; Mytrokhyn, O.; Mashkovska, S.; Foing, B.; Kozyrovska, N.

    It may be assumed that the first plants in a lunar base will play a main role in forming a protosoil of acceptable fertility needed for purposively growing second generation plants like wheat, rice, tulips, etc. The residues of the first-generation plants could be composted and transformed by microorganisms into a soil-like substrate within a loop of regenerative life support system. The lunar regolith may be used as a substrate for plant growth at the very beginning of a mission to reduce its cost. The use of microbial communities for priming plants will allow one to facilitate adaption to stressful conditions and to support the plant development under growth limiting conditions. Well-defined plant-associated bacteria were used for growing three cultivars to colonize French marigold (Tagetes patula L.) in anorthosite, a substrate of low bioavailability, analogous to a lunar rock. The consortium was composed of plant growth promoting rhizobacteria and the bacterium Paenibacillus sp. IMBG156 which stimulated seed germination, better plant development, and finally, the flowering of inoculated tagetes. In contrast, control plants grew poorly in the anorthosite and practically did not survive until flowering. Analysis of bacterial community composition showed that all species colonized plant roots, however, the rate of colonization depended on the allelopatic characteristics of marigold varieties. Bacteria of consortium were able to liberate some elements (Ca, Fe, Mn, Si, Ni, Cu, Zn) from substrate anorthosite. Plant colonization by mixed culture of bacterial strains resulted in the increase of accumulation of K, Mg, Mn by the plant and in the lowering of the level of toxic metal accumulation. It was assumed that a rationally assembled consortium of bacterial strains promoted germination of marygold seeds and supported the plant development under growth limiting conditions by means of bioleaching plant essential nutritional elements and by protecting the plant against

  3. Plant nutrients do not covary with soil nutrients under changing climatic conditions

    NASA Astrophysics Data System (ADS)

    Luo, Wentao; Elser, James J.; Lü, Xiao-Tao; Wang, Zhengwen; Bai, Edith; Yan, Caifeng; Wang, Chao; Li, Mai-He; Zimmermann, Niklaus E.; Han, Xingguo; Xu, Zhuwen; Li, Hui; Wu, Yunna; Jiang, Yong

    2015-08-01

    Nitrogen (N) and phosphorus (P) play vital roles in plant growth and development. Yet how climate regimes and soil fertility influence plant N and P stoichiometry is not well understood, especially in the belowground plant parts. Here we investigated plant aboveground and belowground N and P concentrations ([N] and [P]) and their stoichiometry in three dominant genera along a 2200 km long climatic gradient in northern China. Results showed that temperature explained more variation of [N] and [P] in C4 plants, whereas precipitation exerted a stronger influence on [N] and [P] in C3 plants. Both plant aboveground and belowground [N] and [P] increased with decreasing precipitation, and increasing temperatures yet were negatively correlated with soil [N] and [P]. Plant N:P ratios were unrelated with all climate and soil variables. Plant aboveground and belowground [N] followed an allometric scaling relationship, but the allocation of [P] was isometric. These results imply that internal processes stabilize plant N:P ratios and hence tissue N:P ratios may not be an effective parameter for predicting plant nutrient limitation. Our results also imply that past positive relationships between plant and nutrient stocks may be challenged under changing climatic conditions. While any modeling would need to be able to replicate currently observed relationships, it is conceivable that some relationships, such as those between temperature or rainfall and carbon:nutrient ratios, should be different under changing climatic conditions.

  4. Producing Conditional Mutants for Studying Plant Microtubule Function

    SciTech Connect

    Richard Cyr

    2009-09-29

    The cytoskeleton, and in particular its microtubule component, participates in several processes that directly affect growth and development in higher plants. Normal cytoskeletal function requires the precise and orderly arrangement of microtubules into several cell cycle and developmentally specific arrays. One of these, the cortical array, is notable for its role in directing the deposition of cellulose (the most prominent polymer in the biosphere). An understanding of how these arrays form, and the molecular interactions that contribute to their function, is incomplete. To gain a better understanding of how microtubules work, we have been working to characterize mutants in critical cytoskeletal genes. This characterization is being carried out at the subcellular level using vital microtubule gene constructs. In the last year of funding colleagues have discovered that gamma-tubulin complexes form along the lengths of cortical microtubules where they act to spawn new microtubules at a characteristic 40 deg angle. This finding complements nicely the finding from our lab (which was funded by the DOE) showing that microtubule encounters are angle dependent; high angles encounters results in catastrophic collisions while low angle encounters result in favorable zippering. The finding of a 40 deg spawn of new microtubules from extant microtubule, together with aforementioned rules of encounters, insures favorable co-alignment in the array. I was invited to write a New and Views essay on this topic and a PDF is attached (News and Views policy does not permit funding acknowledgments and so I was not allowed to acknowledge support from the DOE).

  5. Aquatic plant debris improve phosphorus sorption into sediment under anoxic condition.

    PubMed

    Jin, Chong-Wei; Du, Shao-Ting; Dong, Wu-Yuan; Wang, Jue-Hua; Shen, Cheng; Zhang, Yong-Song

    2013-11-01

    The effects of plant debris on phosphorus sorption by anoxic sediment were investigated. Addition of plant debris significantly enhanced the decrease of soluble relative phosphorus (SRP) in overlying water at both 10 and 30 °C during the 30-day investigation. Both cellulose and glucose, two typical plant components, also clearly enhanced the SRP decrease in anoxic overlying water. The measurement of phosphorus (P) fractions in sediment revealed that the levels of unstable P forms were decreased by plant debris addition, whereas the opposites were true for stable P forms. However, under sterilized condition, plant debris/glucose addition has no effect on the SRP decrease in overlying water. Overall, our results suggested that plant debris improve P sorption into sediment under anoxic condition through a microorganism-mediated mechanism. PMID:23686758

  6. Study of seismic design bases and site conditions for nuclear power plants

    SciTech Connect

    Not Available

    1980-04-01

    This report presents the results of an investigation of four topics pertinent to the seismic design of nuclear power plants: Design accelerations by regions of the continental United States; review and compilation of design-basis seismic levels and soil conditions for existing nuclear power plants; regional distribution of shear wave velocity of foundation materials at nuclear power plant sites; and technical review of surface-founded seismic analysis versus embedded approaches.

  7. Computer simulation of equilibrium conditions following a plant 'trip'

    NASA Astrophysics Data System (ADS)

    Limb, D.

    When a process or part of a process experiences an emergency 'trip', the contained fluids redistribute themselves based upon the prevailing pressure gradients and depending upon the positions of valves at the time of the trip. Reverse flow through rotating compression machinery may occur, depending upon the locations of non-return valves. Reduction in pressure and mixing of cryogenic fluids of different compositions and/or temperatures can both lead to generation of significant volumes of vapour. This equilibration process is usually largely over in a matter of seconds rather than minutes. Key questions facing process and mechanical designers are: what is the settle-out pressure, and can we ensure relief valves do not lift following a trip? To answer these related questions it is necessary to analyse the state of the system prior to the trip, and then, based upon valve positions, etc., construct a model of the worst case probable scenarios for the qualitative redistribution of fluid inventory. At this point the simulation program may be employed to help calculate rigorously the final settle out conditions for each of the possible scenarios. This technique is particularly appropriate for cryogenic processes including refrigeration cycles. It is illustrated here with the help of a multistage hydrocarbon compressor example. Other related non-standard applications of the steady state process simulation program are identified.

  8. Form and Actuality

    NASA Astrophysics Data System (ADS)

    Bitbol, Michel

    A basic choice underlies physics. It consists of banishing actual situations from theoretical descriptions, in order to reach a universal formal construct. Actualities are then thought of as mere local appearances of a transcendent reality supposedly described by the formal construct. Despite its impressive success, this method has left major loopholes in the foundations of science. In this paper, I document two of these loopholes. One is the problem of time asymmetry in statistical thermodynamics, and the other is the measurement problem of quantum mechanics. Then, adopting a broader philosophical standpoint, I try to turn the whole picture upside down. Here, full priority is given to actuality (construed as a mode of the immanent reality self-reflectively being itself) over formal constructs. The characteristic aporias of this variety of "Copernican revolution" are discussed.

  9. Ground performance of air conditioning and water recycle system for a space plant box

    NASA Astrophysics Data System (ADS)

    Tani, A.; Okuma, T.; Goto, E.; Kitaya, Y.; Saito, T.; Takahashi, H.

    Researchers from 5 Japanese universities have developed a plant growth facility (Space Plant Box) for seed to seed experiments under microgravity. The breadboard model of the Space Plant Box was fabricated by assembling subsystems developed for microgravity. The subsystems include air conditioning and water recycle system, air circulation system, water and nutrient delivery system, lighting system and plant monitoring system. The air conditioning and water recycle system is simply composed of a single heat exchanger, two fans and hydrophilic fibrous strings. The strings allow water movement from the cooler fin in the Cooling Box to root supporting materials in the Plant Growth Chamber driven by water potential deficit. Relative humidity in the Plant Growth Chamber can be changed over a wide range by controlling the ratio of latent heat exchange to sensible heat exchange on the cooling fin of the heat exchanger. The transpiration rate was successfully measured by circulating air inside the Plant Growth Chamber only. Most water was recycled and a small amount of water needed to be added from the outside. The simple, air conditioning and water recycle system for the Space Plant Box showed good performance through a barley ( Hordeum vulgare L.) growth experiment.

  10. Ground performance of air conditioning and water recycle system for a Space Plant Box.

    PubMed

    Tani, A; Okuma, T; Goto, E; Kitaya, Y; Saito, T; Takahashi, H

    2001-01-01

    Researchers from 5 Japanese universities have developed a plant growth facility (Space Plant Box) for seed to seed experiments under microgravity. The breadboard model of the Space Plant Box was fabricated by assembling subsystems developed for microgravity. The subsystems include air conditioning and water recycle system, air circulation system, water and nutrient delivery system, lighting system and plant monitoring system. The air conditioning and water recycle system is simply composed of a single heat exchanger, two fans and hydrophilic fibrous strings. The strings allow water movement from the cooler fin in the Cooling Box to root supporting materials in the Plant Growth Chamber driven by water potential deficit. Relative humidity in the Plant Growth Chamber can be changed over a wide range by controlling the ratio of latent heat exchange to sensible heat exchange on the cooling fin of the heat exchanger. The transpiration rate was successfully measured by circulating air inside the Plant Growth Chamber only. Most water was recycled and a small amount of water needed to be added from the outside. The simple, air conditioning and water recycle system for the Space Plant Box showed good performance through a barley (Hordeum vulgare L.) growth experiment.

  11. [Animal nutrition for veterinarians--actual cases: tulip bulbs with leaves (Tulipa gesneriana)--an unusual and high risk plant for ruminant feeding].

    PubMed

    Wolf, P; Blanke, H J; Wohlsein, P; Kamphues, J; Stöber, M

    2003-07-01

    14 cattle (mainly younger ones) of a total of 50 extensively kept Galloways died within 6 weeks in late winter 2001/02. According to the owner's report, grass growth had been rather poor; therefore, the herd was fed additionally hay as well as large amounts of tulip onions. In the microbiological examination a highly reduced hygienic quality of the roughage could be detected. In the rumen contents of two dissected young cattle parts of tulip onions were found. According to pertinent literature, tulip onions (in particular their external layers) contain variant-specific amounts of anti-nutritive substances; main active agents are tulipin (a glycoprotein), tuliposid A and B, and lectins. They may cause intensive mucosal irritation, accompanied by reduced feed digestion and body-weight gains, drooling, vomiting and diarrhea. This case report underlines risks caused by feeding of plants originally not destined as forage, if their active ingredients and effects are unknown or remain unconsidered.

  12. Usefulness of LANDSAT data for monitoring plant development and range conditions in California's annual grassland

    NASA Technical Reports Server (NTRS)

    Carneggie, D. M.; Degloria, S. D.; Colwell, R. N.

    1977-01-01

    A network of sampling sites throughout the annual grassland region was established to correlate plant growth in stages and forage production to climatic and other environmental factors. Plant growth and range conditions were further related to geographic location and seasonal variations. A sequence of LANDSAT data was obtained covering critical periods in the growth cycle. Data were analyzed by both photointerpretation and computer aided techniques. Image characteristics and spectral reflectance data were then related to forage production, range condition, range site, and changing growth conditions.

  13. Assessment of inservice conditions of safety-related nuclear plant structures

    SciTech Connect

    Ashar, H.; Bagchi, G.

    1995-06-01

    The report is a compilation from a number of sources of information related to the condition Of structures and civil engineering features at operating nuclear power plants in the United States. The most significant information came from the hands-on inspection of the six old plants (licensed prior to 1977) performed by the staff of the Civil Engineering and Geosciences Branch (ECGB) in the Division of Engineering of the Office of Nuclear Reactor Regulation. For the containment structures, most of the information related to the degraded conditions came from the licensees as part of the Licensing Event Report System (10 CFR 50.73), or as part of the requirement under limiting condition of operation of the plant-specific Technical Specifications. Most of the information related to the degradation of other Structures and civil engineering features was extracted from the industry survey, the reported incidents, and the plant visits. The report discusses the condition of the structures and civil engineering features at operating nuclear power plants and provides information that would help detect, alleviate, and correct the degraded conditions of the structures and civil engineering features.

  14. Theoretical and experimental investigations of thermal conditions of household biogas plant

    NASA Astrophysics Data System (ADS)

    Zhelykh, Vasil; Furdas, Yura; Dzeryn, Oleksandra

    2016-06-01

    The construction of domestic continuous bioreactor is proposed. The modeling of thermal modes of household biogas plant using graph theory was done. The correction factor taking into account with the influence of variables on its value was determined. The system of balance equations for the desired thermal conditions in the bioreactor was presented. The graphical and analytical capabilities were represented that can be applied in the design of domestic biogas plants of organic waste recycling.

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  17. Positive responses of coastal dune plants to soil conditioning by the invasive Lupinus nootkatensis

    NASA Astrophysics Data System (ADS)

    Hanslin, Hans Martin; Kollmann, Johannes

    2016-11-01

    Invasive nitrogen-fixing plants drive vegetation dynamics and may cause irreversible changes in nutrient-limited ecosystems through increased soil resources. We studied how soil conditioning by the invasive alien Lupinus nootkatensis affected the seedling growth of co-occurring native plant species in coastal dunes, and whether responses to lupin-conditioned soil could be explained by fertilisation effects interacting with specific ecological strategies of the native dune species. Seedling performance of dune species was compared in a greenhouse experiment using field-collected soil from within or outside coastal lupin stands. In associated experiments, we quantified the response to nutrient supply of each species and tested how addition of specific nutrients affected growth of the native grass Festuca arundinacea in control and lupin-conditioned soil. We found that lupin-conditioned soil increased seedling biomass in 30 out of 32 native species; the conditioned soil also had a positive effect on seedling biomass of the invasive lupin itself. Increased phosphorus mobilisation by lupins was the major factor driving these positive seedling responses, based both on growth responses to addition of specific elements and analyses of plant available soil nutrients. There were large differences in growth responses to lupin-conditioned soil among species, but they were unrelated to selected autecological indicators or plant strategies. We conclude that Lupinus nootkatensis removes the phosphorus limitation for growth of native plants in coastal dunes, and that it increases cycling of other nutrients, promoting the growth of its own seedlings and a wide range of dune species. Finally, our study indicates that there are no negative soil legacies that prevent re-establishment of native plant species after removal of lupins.

  18. Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

    PubMed Central

    Ghiani, Alessandra; Ciappetta, Silvia; Gentili, Rodolfo; Asero, Riccardo; Citterio, Sandra

    2016-01-01

    Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content. PMID:27457754

  19. Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

    NASA Astrophysics Data System (ADS)

    Ghiani, Alessandra; Ciappetta, Silvia; Gentili, Rodolfo; Asero, Riccardo; Citterio, Sandra

    2016-07-01

    Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content.

  20. Adaptive and selective seed abortion reveals complex conditional decision making in plants.

    PubMed

    Meyer, Katrin M; Soldaat, Leo L; Auge, Harald; Thulke, Hans-Hermann

    2014-03-01

    Behavior is traditionally attributed to animals only. Recently, evidence for plant behavior is accumulating, mostly from plant physiological studies. Here, we provide ecological evidence for complex plant behavior in the form of seed abortion decisions conditional on internal and external cues. We analyzed seed abortion patterns of barberry plants exposed to seed parasitism and different environmental conditions. Without abortion, parasite infestation of seeds can lead to loss of all seeds in a fruit. We statistically tested a series of null models with Monte Carlo simulations to establish selectivity and adaptiveness of the observed seed abortion patterns. Seed abortion was more frequent in parasitized fruits and fruits from dry habitats. Surprisingly, seed abortion occurred with significantly greater probability if there was a second intact seed in the fruit. This strategy provides a fitness benefit if abortion can prevent a sibling seed from coinfestation and if nonabortion of an infested but surviving single seed saves resources invested in the fruit coat. Ecological evidence for complex decision making in plants thus includes a structural memory (the second seed), simple reasoning (integration of inner and outer conditions), conditional behavior (abortion), and anticipation of future risks (seed predation). PMID:24561600

  1. Transient spatio-temporal dynamics of a diffusive plant-herbivore system with Neumann boundary conditions.

    PubMed

    Yu, Fang; Wang, Lin; Watmough, James

    2016-12-01

    In many existing predator-prey or plant-herbivore models, the numerical response is assumed to be proportional to the functional response. In this paper, without such an assumption, we consider a diffusive plant-herbivore system with Neumann boundary conditions. Besides stability of spatially homogeneous steady states, we also derive conditions for the occurrence of Hopf bifurcation and steady-state bifurcation and provide geometrical methods to locate the bifurcation values. We numerically explore the complex transient spatio-temporal behaviours induced by these bifurcations. A large variety of different types of transient behaviours including oscillations in one or both of space and time are observed. PMID:27572052

  2. Responses of Two Invasive Plants Under Various Microclimate Conditions in the Seoul Metropolitan Region

    NASA Astrophysics Data System (ADS)

    Song, Uhram; Mun, Saeromi; Ho, Chang-Hoi; Lee, Eun Ju

    2012-06-01

    The possible consequences of global warming on plant communities and ecosystems have wide-ranging ramifications. We examined how environmental change affects plant growth as a function of the variations in the microclimate along an urban-suburban climate gradient for two allergy-inducing, invasive plants, Humulus japonicus and Ambrosia artemisiifolia var. elatior. The environmental factors and plant growth responses were measured at two urban sites (Gangbuk and Seongbuk) and two suburban sites (Goyang and Incheon) around Seoul, South Korea. The mean temperatures and CO2 concentrations differed significantly between the urban (14.8 °C and 439 ppm CO2) and suburban (13.0 °C and 427 ppm CO2) sites. The soil moisture and nitrogen contents of the suburban sites were higher than those at the urban sites, especially for the Goyang site. The two invasive plants showed significantly higher biomasses and nitrogen contents at the two urban sites. We conducted experiments in a greenhouse to confirm the responses of the plants to increased temperatures, and we found consistently higher growth rates under conditions of higher temperatures. Because we controlled the other factors, the better performance of the two invasive plants appears to be primarily attributable to their responses to temperature. Our study demonstrates that even small temperature changes in the environment can confer significant competitive advantages to invasive species. As habitats become urbanized and warmer, these invasive plants should be able to displace native species, which will adversely affect people living in these areas.

  3. Effect of Plant Species and Environmental Conditions on Ice Nucleation Activity of Pseudomonas syringae on Leaves.

    PubMed

    O'brien, R D; Lindow, S E

    1988-09-01

    Selected plant species and environmental conditions were investigated for their influences on expression of ice nucleation activity by 15 Pseudomonas syringae strains grown on plants in constant-temperature growth chamber studies. Ice nucleation frequencies (INFs), the fraction of cells that expressed ice nucleation at -5 or -9 degrees C, of individual strains varied greatly, both on plants and in culture. This suggests that the probability of frost injury, which is proportional to the number of ice nuclei on leaf surfaces, is strongly determined by the particular bacterial strains that are present on a leaf surface. The INFs of strains were generally higher when they were grown on plants than when they were grown in culture. In addition, INFs in culture did not correlate closely with INFs on plants, suggesting that frost injury prediction should be based on INF measurements of cells grown on plants rather than in culture. The relative INFs of individual strains varied with plant host and environment. However, none of seven plant species tested optimized the INFs of all 15 strains. Similarly, incubation for 48 h at near 100% relative humidity with short photoperiods did not always decrease the INF when compared with a 72 h, 40% relative humidity, long-photoperiod incubation. Pathogenic strains on susceptible hosts were not associated with higher or lower INFs relative to their INFs on nonsusceptible plant species. The ice nucleation activity of individual bacterial strains on plants therefore appears to be controlled by complex and interacting factors such as strain genotype, environment, and host plant species. PMID:16347741

  4. Usefulness of LANDSAT data for monitoring plant development and range conditions in California's annual grassland

    NASA Technical Reports Server (NTRS)

    Carneggie, D. M.; Degloria, S. D.; Colwell, R. N.

    1975-01-01

    A network of sampling sites throughout the annual grassland region of California was established to correlate plant growth stages and forage production to climatic and other environmental factors. Plant growth and range conditions were further related to geographic location and seasonal variations. A sequence of LANDSAT data was obtained covering critical periods in the growth cycle. This was analyzed by both photointerpretation and computer aided techniques. Image characteristics and spectral reflectance data were then related to forage production, range condition, range site and changing growth conditions. It was determined that repeat sequences with LANDSAT color composite images do provide a means for monitoring changes in range condition. Spectral radiance data obtained from magnetic tape can be used to determine quantitatively the critical stages in the forage growth cycle. A computer ratioing technique provided a sensitive indicator of changes in growth stages and an indication of the relative differences in forage production between range sites.

  5. Proposal of a Simple Plant Growth System under Microgravity Conditions in Space

    NASA Astrophysics Data System (ADS)

    Hirai, Hiroaki; Kitaya, Yoshiaki; Hirai, Takehiro; Tsukamoto, Koya; Yamashita, Youichirou

    2012-07-01

    Plant culture in space has multiple functions for human life support such as providing food and purifying air and water. It is also suggested that crew can relieve their stress by watching growing plants and by enjoying fresh vegetable food during staying for several months in the International Space Station. Under such circumstances, it is an utmost importance to develop plant culture equipment that can be handled more easily by crew. This study aims to develop an easy-to-use plant growth system with modification of commercial household plant culture equipment. The item is equipped with a peltier device for cooling air and collecting water vapor in the growth room. The study was conducted to examine the performance of the equipment under microgravity conditions that were created by the parabolic airplane flights. As a result, the temperature of the peltier device was affected under the microgravity conditions due to the absence of heat convection. When an air flow was made with an air circulation fan, the temperature of the peltier device was stable to gravity changes. The water recycling method for an automatic nutrient solution supply system in the closed plant culture equipment under microgravity is proposed. In addition, a high output white LEDs showing a good performance for growing leafy vegetables will be introduced.

  6. Role of microRNAs involved in plant response to nitrogen and phosphorous limiting conditions

    PubMed Central

    Nguyen, Giao N.; Rothstein, Steven J.; Spangenberg, German; Kant, Surya

    2015-01-01

    Plant microRNAs (miRNAs) are a class of small non-coding RNAs which target and regulate the expression of genes involved in several growth, development, and metabolism processes. Recent researches have shown involvement of miRNAs in the regulation of uptake and utilization of nitrogen (N) and phosphorus (P) and more importantly for plant adaptation to N and P limitation conditions by modifications in plant growth, phenology, and architecture and production of secondary metabolites. Developing strategies that allow for the higher efficiency of using both N and P fertilizers in crop production is important for economic and environmental benefits. Improved crop varieties with better adaptation to N and P limiting conditions could be a key approach to achieve this effectively. Furthermore, understanding on the interactions between N and P uptake and use and their regulation is important for the maintenance of nutrient homeostasis in plants. This review describes the possible functions of different miRNAs and their cross-talk relevant to the plant adaptive responses to N and P limiting conditions. In addition, a comprehensive understanding of these processes at molecular level and importance of biological adaptation for improved N and P use efficiency is discussed. PMID:26322069

  7. Proliferation of diversified clostridial species during biological soil disinfestation incorporated with plant biomass under various conditions.

    PubMed

    Mowlick, Subrata; Takehara, Toshiaki; Kaku, Nobuo; Ueki, Katsuji; Ueki, Atsuko

    2013-09-01

    Biological soil disinfestation (BSD) involves the anaerobic decomposition of plant biomass by microbial communities leading to control of plant pathogens. We analyzed bacterial communities in soil of a model experiment of BSD, as affected by biomass incorporation under various conditions, to find out the major anaerobic bacterial groups which emerged after BSD treatments. The soil was treated with Brassica juncea plants, wheat bran, or Avena strigosa plants, irrigated at 20 or 30 % moisture content and incubated at 25-30 °C for 17 days. The population of Fusarium oxysporum f. sp. spinaciae incorporated at the start of the experiment declined markedly for some BSD conditions and rather high concentrations of acetate and butyrate were detected from these BSD-treated soils. The polymerase chain reaction-denaturing gradient gel electrophoresis analysis based on the V3 region of 16S rRNA gene sequences from the soil DNA revealed that bacterial profiles greatly changed according to the treatment conditions. Based on the clone library analysis, phylogenetically diverse clostridial species appeared exceedingly dominant in the bacterial community of BSD soil incorporated with Brassica plants or wheat bran, in which the pathogen was suppressed completely. Species in the class Clostridia such as Clostridium saccharobutylicum, Clostridium acetobutylicum, Clostridium xylanovorans, Oxobacter pfennigii, Clostridium pasteurianum, Clostridium sufflavum, Clostridium cylindrosporum, etc. were commonly recognized as closely related species of the dominant clone groups from these soil samples.

  8. Conditional Facilitation of an Aphid Vector, Acyrthosiphon pisum, by the Plant Pathogen, Pea Enation Mosaic Virus

    PubMed Central

    Hodge, Simon; Powell, Glen

    2010-01-01

    Plant pathogens can induce symptoms that affect the performance of insect herbivores utilizing the same host plant. Previous studies examining the effects of infection of tic bean, Vicia faba L. (Fabales: Fabaceae), by pea enation mosaic virus (PEMV), an important disease of legume crops, indicated there were no changes in the growth and reproductive rate of its primary vector the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). Here, we report the results of laboratory experiments investigating how A. pisum responded to PEMV infection of a different host plant, Pisum sativum L., at different stages of symptom development. Aphid growth rate was negatively related to the age of the host plant, but when they were introduced onto older plants with well-developed PEMV symptoms they exhibited a higher growth rate compared to those developing on uninfected plants of the same age. In choice tests using leaf discs A. pisum showed a strong preference for discs from PEMV-infected peas, probably in response to visual cues from the yellowed and mottled infected leaves. When adults were crowded onto leaves using clip-cages they produced more winged progeny on PEMV-infected plants. The results indicate that PEMV produces symptoms in the host plant that can enhance the performance of A. pisum as a vector, modify the production of winged progeny and affect their spatial distribution. The findings provide further evidence that some insect vector/plant pathogen interactions could be regarded as mutualistic rather than commensal when certain conditions regarding the age, stage of infection and species of host plant are met. PMID:21067425

  9. Linear stable unity-feedback system - Necessary and sufficient conditions for stability under nonlinear plant perturbations

    NASA Technical Reports Server (NTRS)

    Desoer, C. A.; Kabuli, M. G.

    1989-01-01

    The authors consider a linear (not necessarily time-invariant) stable unity-feedback system, where the plant and the compensator have normalized right-coprime factorizations. They study two cases of nonlinear plant perturbations (additive and feedback), with four subcases resulting from: (1) allowing exogenous input to Delta P or not; 2) allowing the observation of the output of Delta P or not. The plant perturbation Delta P is not required to be stable. Using the factorization approach, the authors obtain necessary and sufficient conditions for all cases in terms of two pairs of nonlinear pseudostate maps. Simple physical considerations explain the form of these necessary and sufficient conditions. Finally, the authors obtain the characterization of all perturbations Delta P for which the perturbed system remains stable.

  10. Protein tyrosine nitration in higher plants grown under natural and stress conditions

    PubMed Central

    Corpas, Francisco J.; Palma, José M.; del Río, Luis A.; Barroso, Juan B.

    2013-01-01

    Protein tyrosine nitration is a post-translational modification (PTM) mediated by reactive nitrogen species (RNS) that is linked to nitro-oxidative damages in plant cells. During the last decade, the identification of proteins undergoing this PTM under adverse environmental conditions has increased. However, there is also a basal endogenous nitration which seems to have a regulatory function. The technological advances in proteome analysis have allowed identifying these modified proteins and have shown that the number and identity of the nitrated proteins change among plant species, analysed organs and growing/culture conditions. In this work, the current knowledge of protein tyrosine nitration in higher plants under different situations is reviewed. PMID:23444154

  11. Reevaluation of the plant "gemstones": Calcium oxalate crystals sustain photosynthesis under drought conditions.

    PubMed

    Tooulakou, Georgia; Giannopoulos, Andreas; Nikolopoulos, Dimosthenis; Bresta, Panagiota; Dotsika, Elissavet; Orkoula, Malvina G; Kontoyannis, Christos G; Fasseas, Costas; Liakopoulos, Georgios; Klapa, Maria I; Karabourniotis, George

    2016-09-01

    Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapors, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous exchange of gases is accomplished through the same minute pores on leaf surfaces, called stomata. In a recent study we provided evidence that pigweed, an aggressive weed, attenuates this problem exploiting large crystals of calcium oxalate as dynamic carbon pools. This plant is able to photosynthesize even under drought conditions, when stomata are closed and water losses are limited, using carbon dioxide from crystal decomposition instead from the atmosphere. Abscisic acid, an alarm signal that causes stomatal closure seems to be implicated in this function and for this reason we named this path "alarm photosynthesis." The so-far "enigmatic," but highly conserved and widespread among plant species calcium oxalate crystals seem to play a crucial role in the survival of plants.

  12. Reevaluation of the plant "gemstones": Calcium oxalate crystals sustain photosynthesis under drought conditions.

    PubMed

    Tooulakou, Georgia; Giannopoulos, Andreas; Nikolopoulos, Dimosthenis; Bresta, Panagiota; Dotsika, Elissavet; Orkoula, Malvina G; Kontoyannis, Christos G; Fasseas, Costas; Liakopoulos, Georgios; Klapa, Maria I; Karabourniotis, George

    2016-09-01

    Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapors, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous exchange of gases is accomplished through the same minute pores on leaf surfaces, called stomata. In a recent study we provided evidence that pigweed, an aggressive weed, attenuates this problem exploiting large crystals of calcium oxalate as dynamic carbon pools. This plant is able to photosynthesize even under drought conditions, when stomata are closed and water losses are limited, using carbon dioxide from crystal decomposition instead from the atmosphere. Abscisic acid, an alarm signal that causes stomatal closure seems to be implicated in this function and for this reason we named this path "alarm photosynthesis." The so-far "enigmatic," but highly conserved and widespread among plant species calcium oxalate crystals seem to play a crucial role in the survival of plants. PMID:27471886

  13. Online Condition Monitoring to Enable Extended Operation of Nuclear Power Plants

    SciTech Connect

    Meyer, Ryan M.; Bond, Leonard J.; Ramuhalli, Pradeep

    2012-03-31

    Safe, secure, and economic operation of nuclear power plants will remain of strategic significance. New and improved monitoring will likely have increased significance in the post-Fukushima world. Prior to Fukushima, many activities were already underway globally to facilitate operation of nuclear power plants beyond their initial licensing periods. Decisions to shut down a nuclear power plant are mostly driven by economic considerations. Online condition monitoring is a means to improve both the safety and economics of extending the operating lifetimes of nuclear power plants, enabling adoption of proactive aging management. With regard to active components (e.g., pumps, valves, motors, etc.), significant experience in other industries has been leveraged to build the science base to support adoption for online condition-based maintenance and proactive aging management in the nuclear industry. Many of the research needs are associated with enabling proactive management of aging in passive components (e.g., pipes, vessels, cables, containment structures, etc.). This paper provides an overview of online condition monitoring for the nuclear power industry with an emphasis on passive components. Following the overview, several technology/knowledge gaps are identified, which require addressing to facilitate widespread online condition monitoring of passive components.

  14. CLIMATE CONDITIONS AFFECTING THE WITHIN-PLANT SPREAD OF BROAD MITES ON AZALEA.

    PubMed

    Mechant, E; Pauwels, E; Gobin, B

    2014-01-01

    The broad mite Polyphagotarsonemus latus (Banks) is considered a major pest in potted azalea, Flanders' flagship ornamental crop of Rhododendron simsii hybrids. In addition to severe economic damage, the broad mite is dreaded for its increasing resistance to acaricides. Due to restrictions in the use of broad spectrum acaricides, Belgian azalea growers are left with only three compounds, belonging to two mode of action groups and restricted in their number of applications, for broad mite control: abamectin, milbemectin and pyrethrin. Although P. latus can be controlled with predatory mites, the high cost of this system makes it (not yet) feasible for integration into standard azalea pest management systems. Hence, a maximum efficacy of treatments with available compounds is essential. Because abamectin, milbemectin and pyrethrin are contact acaricides with limited trans laminar flow, only broad mites located on shoot tips of azalea plants will be controlled after spraying. Consequently, the efficacy of chemical treatments is influenced by the location and spread of P. latus on the plant. Unfortunately, little is known on broad mites' within-plant spread or how it is affected by climatic conditions like temperature and relative humidity. Therefore, experiments were set up to verify whether climate conditions have an effect on the location and migration of broad mites on azalea. Broad mite infected azalea plants were placed in standard growth chambers under different temperature (T:2.5-25°C) and relative humidity (RH:55-80%) treatments. Within-plant spread was determined by counting mites on the shoot tips and inner leaves of azalea plants. Results indicate that temperature and relative humidity have no significant effect on the within-plant spread of P. latus. To formulate recommendations for optimal spray conditions to maximize the efficacy of broad mite control with acaricides, further experiments on the effect of light intensity and rain are scheduled.

  15. Responses of Rat Root ( Raf.) Plants to Salinity and pH Conditions.

    PubMed

    Calvo-Polanco, Monica; Alejandra Equiza, María; Señorans, Jorge; Zwiazek, Janusz J

    2014-03-01

    Growth and physiological parameters were examined in rat root ( Raf.) plants grown under controlled environment conditions in hydroponics and subjected to different pH and salinity treatments to determine whether these environmental factors may contribute to poor establishment of in oil sands constructed wetlands. When plants were subjected to a root zone pH ranging from 6.0 to 9.5, the plants that were growing at pH 7.0 showed the highest relative growth rates and chlorophyll concentrations compared with lower and higher pH levels. The greatest inhibition of growth occurred at pH ranging from 8.0 to 9.5. High pH also triggered significant reductions in tissue concentrations of N, P, and microelements, whereas the concentrations of Mg increased at pH >8. When NaCl (25, 50, and 100 mmol L) was added to the nutrient solution at pH 7.0 and 8.5, higher mortality and greater tissue concentrations of Na and Cl were measured in plants growing at pH 8.5 compared with pH 7.0. The results show that plants growing at the optimum pH of 7.0 can better tolerate salinity compared with plants exposed to high root zone pH. Both pH and salinity may present important environmental constraints to growth and establishment of plants in oil sands constructed wetlands. PMID:25602659

  16. Biogeochemical plant site conditions in stream valleys after winter flooding: a phytometer approach

    NASA Astrophysics Data System (ADS)

    Beumer, V.; Ohm, J. N.; van Wirdum, G.; Beltman, B.; Griffioen, J.; Verhoeven, J. T. A.

    2008-12-01

    Reintroduction of winter flooding events will have strong effects on the plant growth conditions in the parts of stream valleys that have not been accustomed to flooding in recent years. The major goal of this research is, firstly, to investigate the plant growth conditions in floodplain soils in the period after a winter flood and, secondly, to assess whether a phytometer setup is suitable for the evaluation of winter flooding on plant growth conditions. Soil cores of three agricultural and three semi-natural grassland sites have been exposed to a simulated winter flooding event. Then, cores were subjected to spring conditions in a growth chamber and were planted with seedlings of Anthoxantum odoratum and Lythrum salicaria. The growth conditions changed in opposite directions for our two phytometer species, expressed as biomass and nutrient changes. We discuss possible causes of an increase or decrease in biomass, such as (1) soil nutrient effects (N, P and K), (2) toxic effects of NH4, Fe and Al, and (3) possible shortage of other macro- and micronutrients. The conclusions are that plant growth after winter flooding was affected by enhanced nutrient and toxicant availabilities in agricultural sites and mainly by soil nutrients in the semi-natural sites. The use of the two species selected had clear advantages: Lythrum salicaria is well-suited to assess the nutrient status in previously flooded soils, because it is a well-known invader of wetlands and not easily hampered by potentially toxic compounds, while A. odoratum is less frequently found at wetland soils and more sensitive to toxic compounds and, therefore, a better indicator of possible toxic effects as a result of winter flooding than L. salicaria.

  17. Quantitative Hydraulic Models Of Early Land Plants Provide Insight Into Middle Paleozoic Terrestrial Paleoenvironmental Conditions

    NASA Astrophysics Data System (ADS)

    Wilson, J. P.; Fischer, W. W.

    2010-12-01

    Fossil plants provide useful proxies of Earth’s climate because plants are closely connected, through physiology and morphology, to the environments in which they lived. Recent advances in quantitative hydraulic models of plant water transport provide new insight into the history of climate by allowing fossils to speak directly to environmental conditions based on preserved internal anatomy. We report results of a quantitative hydraulic model applied to one of the earliest terrestrial plants preserved in three dimensions, the ~396 million-year-old vascular plant Asteroxylon mackei. This model combines equations describing the rate of fluid flow through plant tissues with detailed observations of plant anatomy; this allows quantitative estimates of two critical aspects of plant function. First and foremost, results from these models quantify the supply of water to evaporative surfaces; second, results describe the ability of plant vascular systems to resist tensile damage from extreme environmental events, such as drought or frost. This approach permits quantitative comparisons of functional aspects of Asteroxylon with other extinct and extant plants, informs the quality of plant-based environmental proxies, and provides concrete data that can be input into climate models. Results indicate that despite their small size, water transport cells in Asteroxylon could supply a large volume of water to the plant's leaves--even greater than cells from some later-evolved seed plants. The smallest Asteroxylon tracheids have conductivities exceeding 0.015 m^2 / MPa * s, whereas Paleozoic conifer tracheids do not reach this threshold until they are three times wider. However, this increase in conductivity came at the cost of little to no adaptations for transport safety, placing the plant’s vegetative organs in jeopardy during drought events. Analysis of the thickness-to-span ratio of Asteroxylon’s tracheids suggests that environmental conditions of reduced relative

  18. Gravity-induced cellular and molecular processes in plants studied under altered gravity conditions

    NASA Astrophysics Data System (ADS)

    Vagt, Nicole; Braun, Markus

    With the ability to sense gravity plants possess a powerful tool to adapt to a great variety of environmental conditions and to respond to environmental changes in a most beneficial way. Gravity is the only constant factor that provides organisms with reliable information for their orientation since billions of years. Any deviation of the genetically determined set-point angle of the plants organs from the vector of gravity is sensed by specialized cells, the statocytes of roots and shoots in higher plants. Dense particles, so-called statoliths, sediment in the direction of gravity and activate membrane-bound gravireceptors. A physiological signalling-cascade is initiated that eventually results in the gravitropic curvature response, namely, the readjust-ment of the growth direction. Experiments under microgravity conditions have significantly contributed to our understanding of plant gravity-sensing and gravitropic reorientation. For a gravity-sensing lower plant cell type, the rhizoid of the green alga Chara, and for statocytes of higher plant roots, it was shown that the interactions between statoliths and the actomyosin system consisting of the actin cytoskeleton and motor proteins (myosins) are the basis for highly efficient gravity-sensing processes. In Chara rhizoids, the actomyosin represents a guid-ing system that directs sedimenting statoliths to a specific graviperception site. Parabolic flight experiments aboard the airbus A300 Zero-G have provided evidence that lower and higher plant cells use principally the same statolith-mediated gravireceptor-activation mechanism. Graviper-ception is not dependent on mechanical pressure mediated through the weight of the sedimented statoliths, but on direct interactions between the statoliths's surface and yet unknown gravire-ceptor molecules. In contrast to Chara rhizoids, in the gravity-sensing cells of higher plants, the actin cytoskeleton is not essentially involved in the early phases of gravity sensing. Dis

  19. Effects of contrasting wave conditions on scour and drag on pioneer tidal marsh plants

    NASA Astrophysics Data System (ADS)

    Silinski, Alexandra; Heuner, Maike; Troch, Peter; Puijalon, Sara; Bouma, Tjeerd J.; Schoelynck, Jonas; Schröder, Uwe; Fuchs, Elmar; Meire, Patrick; Temmerman, Stijn

    2016-02-01

    Tidal marshes are increasingly valued for protecting shorelines against wave impact, but waves in turn may limit the initial establishment of tidal marsh pioneer plants. In estuaries, the shorelines typically experience a wide range of wave periods, varying from short period wind waves (usually of around 1-2 s in fair weather conditions) to long ship-generated waves, with secondary waves in the order of 2-7 s and primary waves with periods that can exceed 1 min. Waves are known to create sediment scour around, as well as to exert drag forces on obstacles such as seedlings and adults of establishing pioneer plant species. In intertidal systems, these two mechanisms have been identified as main causes for limiting potential colonization of bare tidal flats. In this paper, we want to assess to which extent common quantitative formulae for predicting local scour and drag forces on rigid cylindrical obstacles are valid for the estimation of scour and drag on slightly flexible plants with contrasting morphology, and hence applicable to predict plant establishment and survival under contrasting wave conditions. This has been tested in a full-scale wave flume experiment on two pioneer species (Scirpus maritimus and Scirpus tabernaemontani) and two life stages (seedlings and adults of S. maritimus) as well as on cylindrical reference sticks, which we have put under a range of wave periods (2-10 s), intended to mimic natural wind waves (short period waves) and ship-induced waves (artificial long period waves), at three water levels (5, 20, 35 cm). Our findings suggest that at very shallow water depths (5 cm) particular hydrodynamic conditions are created that lead to drag and scour that deviate from predictions. For higher water levels (20, 35 cm) scour can be well predicted for all wave conditions by an established formula for wave-induced scour around rigid cylinders. Drag forces can be relatively well predicted after introducing experimentally derived drag coefficients

  20. Effect of some antioxidants on canola plants grown under soil salt stress condition.

    PubMed

    Sakr, M T; Arafa, A A

    2009-04-01

    In this study, two field experiments were carried out during the two growing seasons (2005-2006 and 2006-2007) to investigate the role of some applied antioxidants (spermine 10 mg L(-1) and ascorbic acid 200 mg L(-1)) in counteracting the harmful effect of soil salinity stress (10.1 or 14.6 dS m(-1)) on canola plants. Growth characters, yield and its components as well as biochemical constituents were studied in the two growing seasons. The results showed that all growth characters including; plant height, leaves number and area/plant, shoot and root dry weight as well as yield and its components including; fruit number/plant, number of fruiting branches, seed number/fruit, seed yield/plant and seed oil content of canola plant were decreased with increasing soil salt level (A2) comparing with (A1). On the other hand, applied antioxidants spermine 10 mg L(-1) and ascorbic acid 200 mg L(-1)) increased growth and yield of canola plant during the two growing seasons. However, the applied antioxidants were more effective under the first soil salt condition (A1) soil salt stress levels (A2) decreased each of photosynthetic pigments, K and P contents, while increased proline, soluble sugar, ascorbic acid, Na and Cl contents compared with (A1). On the other hand, applied antioxidants increased each of photosynthetic pigments, proline, soluble sugar, N, K and P contents, while decreased Na and Cl contents in canola plant under soil salt stress (A1 and A2) during the two growing seasons. It could be concluded that applied antioxidants could counteract the harmful effect of salt soil stress on growth, yield and biochemical constituents of canola plant.

  1. Cyp11A1 canola plants under short time heat stress conditions.

    PubMed

    Sakhno, L O; Slyvets, M S; Kuchuk, M V

    2014-01-01

    In order to investigate the high temperature tolerance of spring canola plants (Brassica napus L.) constitutively expressing cyp11A1 gene which encodes bovine cytochrome P450(scc) the growth features were analyzed under short time heat stress (42 degrees C) in growth chamber. Earlier it was documented that results of the heat tolerance test positively correlated with improvement of high temperature resistance in field trial. Higher relative water content (by 13%) and superoxide dismutase (SOD) activity, lower electrolyte leakage (up 1.4-fold) and smaller increase in chlorophyll a and carotenoid contents in cyp11A1 canola leaves in comparison with wild-type plants under stress allowed to conclude cyp11A1 plants are more tolerant to high temperature than the control ones. We suppose that SOD activity increase which revealed in our transgenic canola in normal condition plays the defining role in the biochemical alterations in plant metabolism for the thermotolerance improvement. SOD activity increment could be caused by heterologous cytochrome P450(scc) activity which resulted in the superoxide radical formation. Cyp11A1 canola plants might be resistant to the other stress conditions of different origin.

  2. Optimization of culture conditions of Arnica montana L.: effects of mycorrhizal fungi and competing plants.

    PubMed

    Jurkiewicz, Anna; Ryszka, Przemyslaw; Anielska, Teresa; Waligórski, Piotr; Białońska, Dobroslawa; Góralska, Katarzyna; Tsimilli-Michael, Merope; Turnau, Katarzyna

    2010-06-01

    Arnica montana is a rare plant that needs special protection because of its intensive harvesting for medicinal purposes. The present work was aimed at finding optimal culture conditions for Arnica plants in order to enable their successful reintroduction into their natural stands. Plants were cultivated under controlled greenhouse conditions on substrata with different nitrogen (N) concentration. As Arnica is always colonized by arbuscular mycorrhizal fungi (AMF) in nature, a fact that has been overlooked in other similar projects, we, here, applied and tested different inocula. We found that they differed in their effectiveness, both in establishing symbiosis, assessed by the colonization parameters, and in improving the performance of Arnica, evaluated by the photosynthetic parameters derived from the fluorescence transients (JIP-test), with the inocula containing G. intraradices or composed of several Glomus strains being the most effective. The comparison was possible only on substrata with medium N, since high N did not permit the formation of mycorrhiza, while at low N, few nonmycorrhizal plants survived until the measurements and mycorrhizal plants, which were well growing, exhibited a high heterogeneity. Analysis of secondary metabolites showed clearly that mycorrhization was associated with increased concentrations of phenolic acids in roots. For some of the inocula used, a tendency for increase of the level of phenolic acids in shoots and of sesquiterpene lactones, both in roots and in shoots, was also observed. We also studied the interactions between A. montana and Dactylis glomerata, known to compete with Arnica under field conditions. When specimens from both species were cultured together, there was no effect on D. glomerata, but Arnica could retain a photosynthetic performance that permitted survivability only in the presence of AMF; without AMF, the photosynthetic performance was lower, and the plants were eventually totally outcompeted.

  3. Effect of artificial electric fields on plants grown under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Nechitailo, G.; Gordeev, A.

    2001-01-01

    Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

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

    PubMed

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

    2016-01-01

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

  5. Effect of artificial electric fields on plants grown under microgravity conditions.

    PubMed

    Nechitailo, G; Gordeev, A

    2001-01-01

    Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

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

    PubMed Central

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

    2016-01-01

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

  7. Photosynthesis, transpiration and water use efficiencies of a plant canopy and plant leaves under restricted air current conditions

    NASA Astrophysics Data System (ADS)

    Kitaya, Yoshiaki; Shibuya, Toshio; Tsuruyama, Joshin

    A fundamental study was conducted to obtain the knowledge for culturing plants and exchanging gases with plants under restricted air circulation conditions in space agriculture. The effects of air velocities less than 1.3 m s-1 on net photosynthetic rates (Pn), transpiration rates (Tr) and Pn/Tr, water use efficiencies (WUE), of a canopy of cucumber seedlings and of single leaves of cucumber, sweet potato and barley were assessed with assimilation chamber methods in ground based experiments. The cucumber seedling canopy, which had a LAI of 1.4 and height of 0.1 m, was set in a wind tunnel installed in a plant canopy assimilation chamber. Each of the attached single leaves was set in a leaf assimilation chamber. The Pn and Tr of the plant canopy increased to 1.2 and 2.8 times, respectively, and WUE decreased to 0.4 times with increasing the air velocity from 0.02 to 1.3 m s-1. The Pn and Tr of the single leaves of all the species increased by 1.3-1.7 and 1.9-2.2 times, respectively, and WUE decreased to 0.6-0.8 times as the air velocity increased from 0.05 to 0.8 m s-1. The effect of air velocity was more significant on Tr than on Pn and thus WUE decreased with increasing air velocity in both the plant canopy and the individual leaves. The leaf boundary layer resistance was approximately proportional to the minus 1/3 power of the air velocity. Stomatal resistance was almost constant during the experiment. The CO2 concentrations in the sub-stomatal cavity in leaves of cucumber, sweet potato and barley, respectively, were 43, 31 and 58 mmol mol-1 lower at the air velocity of 0.05 m s-1 than at the air velocity of 0.8 m s-1, while the water vapor pressure in the sub-stomatal cavity was constant. We concluded that the change in the CO2 concentration in the sub-stomatal cavity was a cause of the different effect of the air velocity on Pn and Tr, and thus on WUE. The phenomenon will be more remarkable under restricted air convection conditions at lower gravity in space.

  8. Storage behavior of mango as affected by post harvest application of plant extracts and storage conditions.

    PubMed

    Gupta, Nisha; Jain, S K

    2014-10-01

    The use of plant extracts could be a useful alternative to synthetic fungicides in the post harvest handling of fruits and vegetables. The aim of this study was to access the efficacy of extracts obtained from four plants (neem, Pongamia, custard apple leaf and marigold flowers) on the extension of shelf life of mango fruits cv. Dashehri under two storage conditions (Cool store and ambient condition). The fruits were treated with 2 concentrations of each plant extracts (10 % and 20 %) were placed in perforated linear low density poly ethylene bags and stored in storage conditions viz., cool storage and ambient condition, respectively. The treatment of neem leaf extract in combination with cool storage gave encouraging results. Up to the end of the storage study the treatment combination of 20 % neem leaf extract and cool store completely inhibited the pathogens, and no spoilage was observed. There was minimum physiological loss in weight (6.24 %), minimum girth reduction (0.62 %), maximum ascorbic acid content (29.96 mg/ 100 g of pulp), maximum acidity (0.19 %), minimum pH (5.28), maximum total soluble solids (20.96 %), maximum total sugars (12.50 %), reducing sugars (4.12 %) and non- reducing sugars (7.96 %) and best organoleptic score (7.93/10) in this interaction. The inhibitory effect of neem leaf extract was ascribed to the presence of active principle azadirachtin. PMID:25328189

  9. Summary of investigations of the use of modified turbine inlet conditions in a binary power plant

    SciTech Connect

    G. L. Mines

    2000-09-24

    Investigators at the Idaho National Engineering and Environmental Laboratory (INEEL) are developing technologies that will enhance the feasibility of generating electrical power from a hydrothermal resource. One of the concepts investigated is the use of modified inlet conditions in geothermal binary power plant turbines to increase the power generation. An inlet condition of interest allows the expanding vapor to enter the two-phase region, a mode of operation typically avoided because of concern that condensate would form and damage the turbine, degrading performance. INEEL investigators postulated that initially a supersaturated vapor would be supported, and that no turbine damage would occur. This paper summarizes the investigation of these expansions that began with testing of their condensation behavior, and culminated with the incorporation of these expansions into the operation of several commercial binary plant turbines.

  10. Summary of Investigations of the Use of Modified Turbine Inlet Conditions in a Binary Power Plant

    SciTech Connect

    Mines, Gregory Lee

    2000-09-01

    Investigators at the Idaho National Engineering and Environmental Laboratory (INEEL) are developing technologies that will enhance the feasibility of generating electrical power from a hydrothermal resource. One of the concepts investigated is the use of modified inlet conditions in geothermal binary power plant turbines to increase the power generation. An inlet condition of interest allows the expanding vapor to enter the two-phase region, a mode of operation typically avoided because of concern that condensate would form and damage the turbine, degrading performance. INEEL investigators postulated that initially a supersaturated vapor would be supported, and that no turbine damage would occur. This paper summarizes the investigation of these expansions that began with testing of their condensation behavior, and culminated with the incorporation of these expansions into the operation of several commercial binary plant turbines.

  11. Key Parameters for Operator Diagnosis of BWR Plant Condition during a Severe Accident

    SciTech Connect

    Clayton, Dwight A.; Poore, III, Willis P.

    2015-01-01

    The objective of this research is to examine the key information needed from nuclear power plant instrumentation to guide severe accident management and mitigation for boiling water reactor (BWR) designs (specifically, a BWR/4-Mark I), estimate environmental conditions that the instrumentation will experience during a severe accident, and identify potential gaps in existing instrumentation that may require further research and development. This report notes the key parameters that instrumentation needs to measure to help operators respond to severe accidents. A follow-up report will assess severe accident environmental conditions as estimated by severe accident simulation model analysis for a specific US BWR/4-Mark I plant for those instrumentation systems considered most important for accident management purposes.

  12. 7 CFR 330.203 - Action on applications for permits to move plant pests; form of and conditions in permits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... necessary to prevent dissemination of plant pests into the United States or interstate. Such conditions may... plant pests through the United States will include shipping instructions as to routing, labelling, and... PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of...

  13. 7 CFR 330.203 - Action on applications for permits to move plant pests; form of and conditions in permits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... necessary to prevent dissemination of plant pests into the United States or interstate. Such conditions may... plant pests through the United States will include shipping instructions as to routing, labelling, and... PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of...

  14. 7 CFR 330.203 - Action on applications for permits to move plant pests; form of and conditions in permits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... necessary to prevent dissemination of plant pests into the United States or interstate. Such conditions may... plant pests through the United States will include shipping instructions as to routing, labelling, and... PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of...

  15. Infrared Spectroscopy of Pollen Identifies Plant Species and Genus as Well as Environmental Conditions

    PubMed Central

    Zimmermann, Boris; Kohler, Achim

    2014-01-01

    Background It is imperative to have reliable and timely methodologies for analysis and monitoring of seed plants in order to determine climate-related plant processes. Moreover, impact of environment on plant fitness is predominantly based on studies of female functions, while the contribution of male gametophytes is mostly ignored due to missing data on pollen quality. We explored the use of infrared spectroscopy of pollen for an inexpensive and rapid characterization of plants. Methodology The study was based on measurement of pollen samples by two Fourier transform infrared techniques: single reflectance attenuated total reflectance and transmission measurement of sample pellets. The experimental set, with a total of 813 samples, included five pollination seasons and 300 different plant species belonging to all principal spermatophyte clades (conifers, monocotyledons, eudicots, and magnoliids). Results The spectroscopic-based methodology enables detection of phylogenetic variations, including the separation of confamiliar and congeneric species. Furthermore, the methodology enables measurement of phenotypic plasticity by the detection of inter-annual variations within the populations. The spectral differences related to environment and taxonomy are interpreted biochemically, specifically variations of pollen lipids, proteins, carbohydrates, and sporopollenins. The study shows large variations of absolute content of nutrients for congenital species pollinating in the same environmental conditions. Moreover, clear correlation between carbohydrate-to-protein ratio and pollination strategy has been detected. Infrared spectral database with respect to biochemical variation among the range of species, climate and biogeography will significantly improve comprehension of plant-environment interactions, including impact of global climate change on plant communities. PMID:24748390

  16. Exchange of nitrogen dioxide (NO2) between plants and the atmosphere under laboratory and field conditions

    NASA Astrophysics Data System (ADS)

    Breuninger, C.; Meixner, F. X.; Thielmann, A.; Kuhn, U.; Dindorf, T.; Kesselmeier, J.

    2012-04-01

    Nitric oxide (NO), nitrogen dioxide (NO2), often denoted as nitrogen oxides (NOx), and ozone (O3) are considered as most important compounds in atmospheric chemistry. In remote areas NOx concentration is related to biological activities of soils and vegetation. The emitted NOx will not entirely be subject of long range transport through the atmosphere. Aside oxidation of NO2 by the OH radical (forming HNO3), a considerable part of it is removed from the atmosphere through the uptake of NO2 by plants. The exchange depends on stomatal activity and on NO2 concentrations in ambient air. It is known that NO2 uptake by plants represents a large NO2 sink, but the magnitude and the NO2 compensation point concentration are still under discussion. Our dynamic chamber system allows exchange measurements of NO2 under field conditions (uncontrolled) as well as studies under controlled laboratory conditions including fumigation experiments. For NO2 detection we used a highly NO2 specific blue light converter (photolytic converter) with subsequent chemiluminescence analysis of the generated NO. Furthermore, as the exchange of NO2 is a complex interaction of transport, chemistry and plant physiology, in our field experiments we determined fluxes of NO, NO2, O3, CO2 and H2O. For a better knowledge of compensation point values for the bi-directional NO2 exchange we investigated a primary representative of conifers, Picea abies, under field and laboratory conditions, and re-analyzed older field data of the deciduous tree Quercus robur.

  17. Leaf senescence under various gravity conditions: relevance to the dynamics of plant hormones

    NASA Astrophysics Data System (ADS)

    Miyamoto, K.; Yuda, T.; Shimazu, T.; Ueda, J.

    Effects of simulated microgravity and hypergravity on the senescence of oat leaf segments excised from the primary leaves of 8-d-old green seedlings were studied using a 3-dimensional (D) clinostat as a simulator of weightlessness and a centrifuge, respectively. During the incubation with water under 1-g conditions at 25 °C in the dark, the loss of chlorophyll of the segments was found dramatically immediately after leaf excision, and leaf color completely turned to yellow after 3-d to 4-d incubation. In this case kinetin (10 μM) was effective in retarding senescence. The application of simulated microgravity conditions on a 3-D clinostat enhanced chlorophyll loss in the presence or absence of kinetin. The loss of chlorophyll was also enhanced by hypergravity conditions (ca. 8 to 16 g), but the effect was smaller than that of simulated microgravity conditions on the clinostat. Jasmonates (JAs) and abscisic acid (ABA) promoted senescence under simulated microgravity conditions on the clinostat as well as under 1-g conditions. After 2-d incubation with water or 5-d incubation with kinetin, the endogenous levels of JAs and ABA of the segments kept under simulated microgravity conditions on the clinostat remained higher than those kept under 1-g conditions. These findings suggest that physiological processes of leaf senescence and the dynamics of endogenous plant hormone levels are substantially affected by gravity.

  18. INITIAL CHEMICAL AND RESERVOIR CONDITIONS AT LOS AZUFRES WELLHEAD POWER PLANT STARTUP

    SciTech Connect

    Kruger, P.; Semprini, L.; Verma, S.; Barragan, R.; Molinar, R.; Aragon, A.; Ortiz, J.; Miranda, C.

    1985-01-22

    One of the major concerns of electric utilities in installing geothermal power plants is not only the longevity of the steam supply, but also the potential for changes in thermodynamic properties of the resource that might reduce the conversion efficiency of the design plant equipment. Production was initiated at Los Azufres geothermal field with wellhead generators not only to obtain electric energy at a relatively early date, but also to acquire needed information about the resource so that plans for large central power plants could be finalized. Commercial electric energy production started at Los Azufres during the summer of 1982 with five 5-MWe wellhead turbine-generator units. The wells associated with these units had undergone extensive testing and have since been essentially in constant production. The Los Azufres geothermal reservoir is a complex structural and thermodynamic system, intersected by at least 4 major parallel faults and producing geothermal fluids from almost all water to all steam. The five wellhead generators are associated with wells of about 30%, 60%, and 100% steam fraction. A study to compile existing data on the chemical and reservoir conditions during the first two years of operation has been completed. Data have been compiled on mean values of wellhead and separator pressures, steam and liquid flowrates, steam fraction, enthalpy, and pertinent chemical components. The compilation serves both as a database of conditions during the start-up period and as an initial point to observe changes with continued and increased production. Current plans are to add additional wellhead generators in about two years followed by central power plants when the data have been sufficiently evaluated for optimum plant design. During the next two years, the data acquired at the five 5-MWe wellhead generator units can be compared to this database to observe any significant changes in reservoir behavior at constant production.

  19. The effects of repeated planting, planting density, and specific transfer pathways on PCB uptake by Cucurbita pepo grown in field conditions.

    PubMed

    Whitfield Aslund, Melissa L; Rutter, Allison; Reimer, Kenneth J; Zeeb, Barbara A

    2008-11-01

    An in situ field investigation into the potential of PCB phytoextraction by Cucurbita pepo ssp. pepo (pumpkin) plants was continued for a second year at a field site known to be contaminated with a mixture of Aroclors 1254 and 1260 (average soil [PCB]=21 microg/g). Plant stem and leaf PCB concentrations in this second field season (11 and 8.9 microg/g, respectively) were observed to increase significantly from the stem and leaf PCB concentrations reported in the previous year (5.7 and 3.9 microg/g, respectively) while the total biomass produced as well as soil and plant root PCB concentrations did not change. Furthermore, the lower stems of some plants exhibited PCB concentrations as high as 43 microg/g, resulting in bioaccumulation factors (where BAF(plant part)=[PCB](plant part)/[PCB](soil)) for parts of the plant shoot as high as 2. Increased planting density was observed to significantly decrease both plant biomass and plant stem PCB concentrations (to 7.7 microg/g), but did not change plant root PCB concentrations. Finally, the results from this study provided further evidence that that under realistic field conditions, PCB transfer to pumpkin plants was primarily via root uptake and translocation. Other contaminant transfer pathways such as direct soil contamination, atmospheric deposition and volatilization from soil and subsequent redeposition on shoots appeared to have negligible contributions to overall pumpkin plant PCB burdens.

  20. Impact of climatic conditions on the design of a water treatment plant

    NASA Astrophysics Data System (ADS)

    Arregoitia, C.; Mesa, M. P.

    2012-04-01

    The abundance or scarcity of resources causes enormous problems for populations and societies. They mark the direction of the development that a society will take. Water imbalances, may distort optimal environmental and socioeconomic conditions of the food production. Water scarcity may limit food production and supply, putting pressure on food prices and increasing countries' dependence on food imports. Rising demand for food caused by growing populations and shifting diets, production shortfall in some countries, increased costs for key agricultural inputs and meat supply (driven in turn by energy costs), bioenergy-related incentives in some countries and possible financial speculation have all contributed to the steep rises in food prices. According to United Nations Over the past century world water withdrawals increased almost twice as fast as population growth and an increasing number of regions are chronically water short. Climate change has been defined as a change in the statistical properties of the climate system when considered over long periods of time, regardless of cause. Different factors can shape the climate forces or mechanisms and impact the food production system such as the cattle production field. This paper considers the step by step design and implementation of a water treatment plant of a community cattle farm located in Jadacaquiva under changing climatic conditions. The byproducts of the cattle, as well as the community can also have an impact depending on the decisions taken for the plant. Keywords: water, climate change, treatment plant, food scarcity

  1. The hidden function of photosynthesis: a sensing system for environmental conditions that regulates plant acclimation responses.

    PubMed

    Pfannschmidt, Thomas; Yang, Chunhong

    2012-06-01

    Plants convert light energy from the sun into chemical energy by photosynthesis. Since they are sessile, they have to deal with a wide range of conditions in their immediate environment. Many abiotic and biotic parameters exhibit considerable fluctuations which can have detrimental effects especially on the efficiency of photosynthetic light harvesting. During evolution, plants, therefore, evolved a number of acclimation processes which help them to adapt photosynthesis to such environmental changes. This includes protective mechanisms such as excess energy dissipation and processes supporting energy redistribution, e.g. state transitions or photosystem stoichiometry adjustment. Intriguingly, all these responses are triggered by photosynthesis itself via the interplay of its light reaction and the Calvin-Benson cycle with the residing environmental condition. Thus, besides its primary function in harnessing and converting light energy, photosynthesis acts as a sensing system for environmental changes that controls molecular acclimation responses which adapt the photosynthetic function to the environmental change. Important signalling parameters directly or indirectly affected by the environment are the pH gradient across the thylakoid membrane and the redox states of components of the photosynthetic electron transport chain and/or electron end acceptors coupled to it. Recent advances demonstrate that these signals control post-translational modifications of the photosynthetic protein complexes and also affect plastid and nuclear gene expression machineries as well as metabolic pathways providing a regulatory framework for an integrated response of the plant to the environment at all cellular levels.

  2. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions.

    PubMed

    Lebedev, V G; Faskhiev, V N; Kovalenko, N P; Shestibratov, K A; Miroshnikov, A I

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014-2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity. PMID:27437143

  3. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions.

    PubMed

    Lebedev, V G; Faskhiev, V N; Kovalenko, N P; Shestibratov, K A; Miroshnikov, A I

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014-2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity.

  4. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions

    PubMed Central

    Lebedev, V. G.; Faskhiev, V. N.; Kovalenko, N. P.; Shestibratov, K. A.; Miroshnikov, A. I.

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014–2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity. PMID:27437143

  5. In-vitro bioactivity of Venda medicinal plants used in the treatment of respiratory conditions.

    PubMed

    Pallant, Ca; Steenkamp, V

    2008-11-01

    Infectious diseases, especially those affecting the respiratory tract, represent a critical problem to health. Crude methanol and water extracts of 10 Venda plants reported to be used ethnomedically in the treatment of respiratory conditions were assessed for their antimicrobial activity against standard strains and clinical isolates of Candida albicans, Haemophilis influenzae, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pneumoniae, and Mycobacterium smegmatis using the disc diffusion assay. Four of the 10 plants tested possessed antimicrobial activity, but no activity against K. pneumoniae was observed. Minimum inhibitory concentrations, as determined by the broth microdilution assay, showed three plants, Securidaca longepedunculata, Syzygium cordatum, and Tabernaemontana elegans, to possess MICs plant species with significant antimicrobial activity were identified, there is a need for further scientific evaluation regarding identification of the bioactive constituents, as well as their toxicity. PMID:19244294

  6. Studies on gene expressions analyses for Arabidopsis thaliana plants stimulated by space flight condition

    NASA Astrophysics Data System (ADS)

    Lu, Jinying; Liu, Min; Pan, Yi; Li, Huasheng

    We carried out whole-genome microarray to screen the transcript profile of Arabidopsis thaliana seedlings after three treatment: space microgravity condition( Seedlings grown in microgravity state of space flight of SIMBOX on Shenzhou-8), 1g centrifugal force in space(Seedlings grown in 1g centrifugal force state of space flight of SIMBOX on Shenzhou-8) and ground control. The result of microarray analysis is as followed: There were 368 genes significantly differentially expressed in space microgravity condition compared with that in 1g centrifuge space condition. Space radiation caused 246 genes significantly differentially expressed between seedlings in 1g centrifuge space condition and ground control. Space conditions (including microgravity and radiation) caused 621 genes significantly differentially expressed between seedlings in space microgravity condition and ground control. Microgravity and radiation as a single factor can cause plant gene expression change, but two factors synergism can produce some new effects on plant gene expression. The function of differential expression genes were analyst by bioinformatics, and we found the expression of genes related with stress were more different, such as the dehydration of protein (dehydrin Xero2) expression is up-regulated 57 times; low-temperature-induced protein expression is up-regulated in 49 times; heat shock protein expression is up-regulated 20 times; transcription factor DREB2A expression increase 25 times; protein phosphatase 2C expression is up-regulated 14 times; transcription factor NAM-like protein expression is up-regulated 13 times; cell wall metabolism related genes (xyloglucan, endo-1, 4-beta-D-glucanase) expression is down-regulated in 15 times. The results provide scientific data for the mechanism of space mutation.

  7. Partitioning of Evapotranspiration Into Soil Evaporation and Plant Transpiration Using Isotopes of Water in Controlled Conditions

    NASA Astrophysics Data System (ADS)

    Rothfuss, Y.; Bariac, T.; Braud, I.; Biron, P.; Richard, P.; Canale, L.; Durand, J.; Gaudet, J.

    2007-12-01

    Rainfall recycling by evapotranspiration from continental surfaces is certainly the most unknown component of the global water cycle. This is due to the large variability of rainfall as well as the heterogeneity of these continental surfaces, both in time and space. Traditional measuring methods such as sap flow, micro lysimeter, water and energy balance estimation (Bowen ratio, eddy correlation) have been used since the 70s for a monitoring of real evapotranspiration fluxes over crops and others plant covers. A complementary method consists in using isotopic biogeochemistry. When making specific hypothesis, it is possible to identify and quantify the different sources of the atmospheric water vapour (vegetation and soil at different scales). Analysis of the heavy stable isotopic ratios of water in both liquid and vapour phases: 18O and 2H can allow determining the history of the water in the soil since the last rainfall event (infiltration, re-evaporation) or the root extraction depths. Field campaigns measurements (plants and soils), interpreted using the Keeling Plot method allowed some progress in the partition between evaporation and transpiration understanding. But the experimental design is not sufficient to mechanistically describe the water processes involved. The study of all the interactions is difficult due to the large number of controlling variables describing climate, vegetation and soil characteristics. A monolith experiment (including soil and growing plant) was carried out in a reactor called RUBIC (Reactor Used for Continental Isotopic Biogeochemistry, Bariac et al., Geochim. Cosmochim. Acta., 1991). Controlled conditions allowed a monitoring and regulation of climatic parameters (net radiation, air temperature, vapour pressure deficit, CO2 partial pressure, and wind speed). It was also necessary to fix soil (structure, texture, and water content) and vegetation (specie and seeding density) parameters. The collected data allow us to improve our

  8. Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes

    USGS Publications Warehouse

    Espinar, J.L.; Garcia, L.V.; Clemente, L.

    2005-01-01

    The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.

  9. Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes.

    PubMed

    Espinar, José L; García, Luis V; Clemente, Luis

    2005-07-01

    The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three salt-marsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management. PMID:21646131

  10. The Performance of Plants, Molluscs, and Carabid Beetles as Indicators of Hydrological Conditions in Floodplain Grasslands

    NASA Astrophysics Data System (ADS)

    Follner, Klaus; Henle, Klaus

    2006-08-01

    Floodplain systems are among the most complex ecosystems. To assess their ecological condition, several indicator systems have been developed. However, none of them quantifies environmental factors related to the dynamics of water levels, which is a major driver for the occurrence and distribution of species in floodplains. We present a new bioindicator system for the duration of inundation per year and mean depth of groundwater during the vegetation period. The new indicator system is based on carabid beetles, molluscs, and plants. The indicator system generally proved to be precise as well as temporally and spatially transferable within the same river system, the Elbe River in Germany. The indication based on plants was clearly most precise and transferable. The results are discussed in terms of application of the indicator system.

  11. Induction of a dwarf phenotype with IBH1 may enable increased production of plant-made pharmaceuticals in plant factory conditions.

    PubMed

    Nagatoshi, Yukari; Ikeda, Miho; Kishi, Hiroyuki; Hiratsu, Keiichiro; Muraguchi, Atsushi; Ohme-Takagi, Masaru

    2016-03-01

    Year-round production in a contained, environmentally controlled 'plant factory' may provide a cost-effective method to produce pharmaceuticals and other high-value products. However, cost-effective production may require substantial modification of the host plant phenotype; for example, using dwarf plants can enable the growth of more plants in a given volume by allowing more plants per shelf and enabling more shelves to be stacked vertically. We show here that the expression of the chimeric repressor for Arabidopsis AtIBH1 (P35S:AtIBH1SRDX) in transgenic tobacco plants (Nicotiana tabacum) induces a dwarf phenotype, with reduced cell size. We estimate that, in a given volume of cultivation space, we can grow five times more AtIBH1SRDX plants than wild-type plants. Although, the AtIBH1SRDX plants also showed reduced biomass compared with wild-type plants, they produced about four times more biomass per unit of cultivation volume. To test whether the dwarf phenotype affects the production of recombinant proteins, we expressed the genes for anti-hepatitis B virus antibodies (anti-HBs) in tobacco plants and found that the production of anti-HBs per unit fresh weight did not significantly differ between wild-type and AtIBH1SRDX plants. These data indicate that P35S:AtIBH1SRDX plants produced about fourfold more antibody per unit of cultivation volume, compared with wild type. Our results indicate that AtIBH1SRDX provides a useful tool for the modification of plant phenotype for cost-effective production of high-value products by stably transformed plants in plant factory conditions.

  12. Power conditioning subsystems for photovoltaic central-station power plants - Technology and performance

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.; Das, R.; Bulawka, A.

    1985-01-01

    Central-Station (CS) Photovoltaic (PV) systems have the potential of economically displacing significant amounts of centrally generated electricity. However, the technical viability and, to some extent, the economic viability of central-station PV generation technology will depend upon the availability of large power conditioners that are efficient, safe, reliable, and economical. This paper is an overview of the technical and cost requirements that must be met to develop economically viable power conditioning subsystems (PCS) for central-station power plants. The paper also examines various already commercially available PCS hardware that may be suitable for use in today's central PV power stations.

  13. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [south Texas

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1981-01-01

    Emissive and reflective data for 10 days, and IR data for 6 nights in south Texas scenes were analyzed after procedures were developed for removing cloud-affected data. HCMM radiometric temperatures were: within 2 C of dewpoint temperatures on nights when air temperature approached dewpoint temperatures; significantly correlated with variables important in evapotranspiration; and, related to freeze severity and planting depth soil temperatures. Vegetation greenness indexes calculated from visible and reflective IR bands of NOAA-6 to -9 meteorological satellites will be useful in the AgRISTARS program for seasonal crop development, crop condition, and drought applications.

  14. Identification of environmental factors limiting plant uptake of metaldehyde seed treatments under field conditions.

    PubMed

    Simms, Louise C; Dawson, Julian J C; Paton, Graeme I; Wilson, Michael J

    2006-05-17

    Slugs are serious pests of oilseed rape (canola) and wheat with most damage occurring just after sowing and seedling emergence. As an alternative to the use of bait pellets, molluscicidal seed treatments have been shown to protect seeds and seedlings from slug damage in laboratory and semi-field experiments. However, protection offered to plants in field trials was diminished and shortlived in comparison with laboratory experiments. To determine why field efficacy was reduced, we grew seedlings under a range of environmental conditions, with appropriate controls, that simulated differences between laboratory and field experiments. We then measured the metaldehyde content of plant seedlings using a previously unpublished methodology described herein, which, unlike previous methods, did not first depolymerize the metaldehyde to acetaldehyde. We confirmed that naturally abundant plant-derived acetaldehyde could not interfere with our measurements of metaldehyde, even if depolymerization took place within the column. Our data suggest that reduced field efficacy results from microbial breakdown and/or loss of active ingredient caused by percolating soil water. Once the seedlings had emerged, neither volatalization nor simulated rainwater reduced the metaldehyde content of seedlings. Our findings will help develop superior seed treatment formulations to overcome these constraints.

  15. Control of Xiphinema index populations by fallow plants under greenhouse and field conditions.

    PubMed

    Villate, Laure; Morin, Elisa; Demangeat, Gérard; Van Helden, Maarten; Esmenjaud, Daniel

    2012-06-01

    The dagger nematode Xiphinema index has a high economic impact in vineyards by direct pathogenicity and above all by transmitting the Grapevine fanleaf virus (GFLV). Agrochemicals have been largely employed to restrict the spread of GFLV by reducing X. index populations but are now banned. As an alternative to nematicides, the use of fallow plants between two successive vine crops was assessed. We selected plant species adapted to vineyard soils and exhibiting negative impact on nematodes and we evaluated their antagonistic effect on X. index in greenhouse using artificially infested soil, and in naturally infested vineyard conditions. The screening was conducted with plants belonging to the families Asteraceae (sunflower, marigold, zinnia, and nyjer), Poaceae (sorghum and rye), Fabaceae (white lupin, white melilot, hairy vetch, and alfalfa), Brassicaceae (rapeseed and camelina), and Boraginaceae (phacelia). In the greenhouse controlled assay, white lupin, nyjer, and marigold significantly reduced X. index populations compared with that of bare soil. The vineyard assay, designed to take into account the aggregative pattern of X. index distribution, revealed that marigold and hairy vetch are good candidates as cover crops to reduce X. index populations in vineyard. Moreover, this original experimental design could be applied to manage other soilborne pathogens.

  16. Identification of environmental factors limiting plant uptake of metaldehyde seed treatments under field conditions.

    PubMed

    Simms, Louise C; Dawson, Julian J C; Paton, Graeme I; Wilson, Michael J

    2006-05-17

    Slugs are serious pests of oilseed rape (canola) and wheat with most damage occurring just after sowing and seedling emergence. As an alternative to the use of bait pellets, molluscicidal seed treatments have been shown to protect seeds and seedlings from slug damage in laboratory and semi-field experiments. However, protection offered to plants in field trials was diminished and shortlived in comparison with laboratory experiments. To determine why field efficacy was reduced, we grew seedlings under a range of environmental conditions, with appropriate controls, that simulated differences between laboratory and field experiments. We then measured the metaldehyde content of plant seedlings using a previously unpublished methodology described herein, which, unlike previous methods, did not first depolymerize the metaldehyde to acetaldehyde. We confirmed that naturally abundant plant-derived acetaldehyde could not interfere with our measurements of metaldehyde, even if depolymerization took place within the column. Our data suggest that reduced field efficacy results from microbial breakdown and/or loss of active ingredient caused by percolating soil water. Once the seedlings had emerged, neither volatalization nor simulated rainwater reduced the metaldehyde content of seedlings. Our findings will help develop superior seed treatment formulations to overcome these constraints. PMID:19127739

  17. Life history of Paracoccus marginatus (Hemiptera: Pseudococcidae) on four host plant species under laboratory conditions.

    PubMed

    Amarasekare, Kaushalya G; Mannion, Catharine M; Osborne, Lance S; Epsky, Nancy D

    2008-06-01

    Life history of the mealybug, Paracoccus marginatus Williams and Granara de Willink, on three ornamental plants [Hibiscus rosa-sinensis L., Acalypha wilkesiana (Muell.-Arg.), and Plumeria rubra L.] and one weed species (Parthenium hysterophorus L.) was studied under laboratory conditions. Mealybugs were able to develop, survive, and reproduce on all four hosts; however, there were differences in the life history parameters. Adult females that developed on acalypha and parthenium emerged approximately 1 d earlier than those that developed on hibiscus and plumeria. Adult males had a longer developmental time on plumeria than on the other hosts. Survival of first- and second-instar nymphs and cumulative adult survival were lowest on plumeria. Longevity was not affected by hosts for males and females and averaged 2.3 +/- 0.1 and 21.2 +/- 0.1 d, respectively. On plumeria, 58.9 +/- 1.7% of the adults were females, which was a higher female percentage than on the other hosts. No egg production occurred in virgin females. Prereproductive and reproductive periods of the females were not affected by hosts and averaged 6.3 +/- 0.1 and 11.2 +/- 0.1 d, respectively. Mean fecundity of 186.3 +/- 1.8 eggs on plumeria was lower than on the other three plant species. Life history parameters of P. marginatus on hibiscus, acalypha, plumeria, and parthenium show its ability to develop, survive, and reproduce on a wide variety of plant species.

  18. Influence of wastewater treatment plants' operational conditions on activated sludge microbiological and morphological characteristics.

    PubMed

    Amanatidou, Elisavet; Samiotis, Georgios; Trikoilidou, Eleni; Tzelios, Dimitrios; Michailidis, Avraam

    2016-01-01

    The effect of wastewater composition and operating conditions in activated sludge (AS) microbiological and morphological characteristics was studied in three AS wastewater treatment plants (WWTPs): (a) a high organic load slaughterhouse AS WWTP, operating at complete solids retention, monitored from its start-up and for 425 days; (b) a seasonally operational, low nitrogen load fruit canning industry AS WWTP, operating at complete solids retention, monitored from its start-up and until the end of the season (87 days); (c) a municipal AS WWTP, treating wastewater from a semi-combined sewer system, monitored during the transitions from dry to rainy and again to dry periods of operation. The sludge microbiological and morphological characteristics were correlated to nutrients' availability, solids retention time, hydraulic retention time, dissolved oxygen, mixed liquor suspended solids (MLVSS), organic load (F/M) and substrate utilization rate. The AS WWTPs' operation was distinguished in periods based on biomass growth phase, characterized by different biological and morphological characteristics and on operational conditions. An anoxic/aerobic selector minimizes the readily biodegradable compounds in influent, inhibiting filamentous growth. Plant performance controlling is presented in a logic flowchart in which operational parameters are linked to microbial manipulation, resulting in a useful tool for researchers and engineers. PMID:26145184

  19. Influence of wastewater treatment plants' operational conditions on activated sludge microbiological and morphological characteristics.

    PubMed

    Amanatidou, Elisavet; Samiotis, Georgios; Trikoilidou, Eleni; Tzelios, Dimitrios; Michailidis, Avraam

    2016-01-01

    The effect of wastewater composition and operating conditions in activated sludge (AS) microbiological and morphological characteristics was studied in three AS wastewater treatment plants (WWTPs): (a) a high organic load slaughterhouse AS WWTP, operating at complete solids retention, monitored from its start-up and for 425 days; (b) a seasonally operational, low nitrogen load fruit canning industry AS WWTP, operating at complete solids retention, monitored from its start-up and until the end of the season (87 days); (c) a municipal AS WWTP, treating wastewater from a semi-combined sewer system, monitored during the transitions from dry to rainy and again to dry periods of operation. The sludge microbiological and morphological characteristics were correlated to nutrients' availability, solids retention time, hydraulic retention time, dissolved oxygen, mixed liquor suspended solids (MLVSS), organic load (F/M) and substrate utilization rate. The AS WWTPs' operation was distinguished in periods based on biomass growth phase, characterized by different biological and morphological characteristics and on operational conditions. An anoxic/aerobic selector minimizes the readily biodegradable compounds in influent, inhibiting filamentous growth. Plant performance controlling is presented in a logic flowchart in which operational parameters are linked to microbial manipulation, resulting in a useful tool for researchers and engineers.

  20. Expression of Rhizobial Nitrogenase: Influence of Plant Cell-Conditioned Medium †

    PubMed Central

    Bednarski, Mary Ann; Reporter, Minocher

    1978-01-01

    Conditioned medium was obtained from suspension cultures of soybean (Glycine max L. Merrit) cells after incubating them for 4 to 8 days with rhizobia which were separated from the soybean cells by two dialysis bags, one within another. This conditioned medium from the plant cell side (PCM) of the two membranes was used to elicit and influence nitrogenase activity (acetylene reduction) in rhizobia. When conditions for obtaining PCM from the soybean cell suspension cultures were varied, it could be shown that freshly grown rhizobia were able to induce active compounds in the PCM. These compounds caused acetylene reduction activity in test rhizobia under conditions where control rhizobia, containing various substrates, showed little or no acetylene reduction activity. Rhizobia that were already capable of acetylene reduction could not induce such compounds in the PCM when this was included with test rhizobia. The PCM from soybean cultures was also found to aid the expression of nitrogenase activity in suspension cultures of rhizobia normally associated with either peas, lupins, broad beans, or clovers. This is the first communication indicating nitrogenase activity in freeliving cultures for various species of rhizobia. PMID:16345300

  1. Antioxidants in Erica andevalensis: a comparative study between wild plants and cadmium-exposed plants under controlled conditions.

    PubMed

    Márquez-García, Belén; Horemans, Nele; Cuypers, Ann; Guisez, Yves; Córdoba, Francisco

    2011-01-01

    Erica andevalensis is an endemic species from SW Iberian Peninsula, always growing in metal-enriched and acid soils. In the present study, a comparison was made between wild E. andevalensis plants collected from the field and cultivated ones exposed to different cadmium levels (0, 0.5, 5 and 50 μM). Wild plants contain higher levels of ascorbic acid (around 8000 nmol g(-1) FW) than lab-cultivated control plants (around 3000 nmol g(-1) FW). Glutathione levels follow an opposite trend being smaller in wild plants than lab-cultivated ones. Moreover, the total antioxidant capacity of wild plants is 90 times higher than in cultivated plants non-exposed to cadmium. Cadmium treatment of lab-cultivated plants did not affect the growth of E. andevalensis or the glutathione levels. However, the total antioxidative capacity increased in plants exposed to 50 μM of cadmium. Cadmium was added to the soil and it was transported into leaves reaching levels of 3.299 ± 0.781 μg Cd/g DW in plants exposed to 50 μM. These results underline a possible importance of antioxidants in the metal tolerance show by the high antioxidant capacity detected in both wild and lab-cultivated plants exposed to high cadmium levels.

  2. Mycorrhizal association between the desert truffle Terfezia boudieri and Helianthemum sessiliflorum alters plant physiology and fitness to arid conditions.

    PubMed

    Turgeman, Tidhar; Asher, Jiftach Ben; Roth-Bejerano, Nurit; Kagan-Zur, Varda; Kapulnik, Yoram; Sitrit, Yaron

    2011-10-01

    The host plant Helianthemum sessiliflorum was inoculated with the mycorrhizal desert truffle Terfezia boudieri Chatin, and the subsequent effects of the ectomycorrhizal relationship on host physiology were determined. Diurnal measurements revealed that mycorrhizal (M) plants had higher rates of photosynthesis (35%), transpiration (18%), and night respiration (49%) than non-mycorrhizal (NM) plants. Consequently, M plants exhibited higher biomass accumulation, higher shoot-to-root ratios, and improved water use efficiency compared to NM plants. Total chlorophyll content was higher in M plants, and the ratio between chlorophyll a to chlorophyll b was altered in M plants. The increase in chlorophyll b content was significantly higher than the increase in chlorophyll a content (2.58- and 1.52-fold, respectively) compared to control. Calculation of the photosynthetic activation energy indicated lower energy requirements for CO(2) assimilation in M plants than in NM plants (48.62 and 61.56 kJ mol(-1), respectively). Continuous measurements of CO(2) exchange and transpiration in M plants versus NM plants provided a complete picture of the daily physiological differences brought on by the ectomycorrhizal relationships. The enhanced competence of M plants to withstand the harsh environmental conditions of the desert is discussed in view of the mycorrhizal-derived alterations in host physiology.

  3. AgRISTARS: Early warning and crop condition assessment. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L. (Principal Investigator); Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J.

    1981-01-01

    Emissive (10.5 to 12.5 microns) and reflective (0.55 to 1.1 microns) data for ten day scenes and infrared data for six night scenes of southern Texas were analyzed for plant cover, soil temperature, freeze, water stress, and evapotranspiration. Heat capacity mapping mission radiometric temperatures were: within 2 C of dewpoint temperatures, significantly correlated with variables important in evapotranspiration, and related to freeze severity and planting depth soil temperatures.

  4. Growth and development in higher plants under simulated microgravity conditions on a 3-dimensional clinostat

    NASA Astrophysics Data System (ADS)

    Shimazu, T.; Yuda, T.; Miyamoto, K.; Yamashita, M.; Ueda, J.

    Growth and development of etiolated pea (Pisum sativum L. cv. Alaska) and maize (Zea mays L. cv. Golden Cross Bantam) seedlings grown under simulated microgravity conditions were intensively studied using a 3-dimensional clinostat as a simulator of weightlessness. Epicotyls of etiolated pea seedlings grown on the clinostat were the most oriented toward the direction far from cotyledons. Mesocotyls of etiolated maize seedlings grew at random and coleoptiles curved slightly during clinostat rotation. Clinostat rotation promoted the emergence of the 3rd internodes in etiolated pea seedlings, while it significantly inhibited the growth of the 1st internodes. In maize seedlings, the growth of coleoptiles was little affected by clinostat rotation, but that of mesocotyls was suppressed, and therefore, the emergence of the leaf out of coleoptile was promoted. Clinostat rotation reduced the osmotic concentration in the 1st internodes of pea seedlings, although it has little effect on the 2nd and the 3rd internodes. Clinostat rotation also reduced the osmotic concentrations in both coleoptiles and mesocotyls of maize seedlings. Cell-wall extensibilities of the 1st and the 3rd internodes of pea seedlings grown on the clinostat were significantly lower and higher as compared with those on 1 g conditions, respectively. Cell-wall extensibility of mesocotyls in seedlings grown on the clinostat also decreased. Changes in cell wall properties seem to be well correlated to the growth of each organ in pea and maize seedlings. These results suggest that the growth and development of plants is controlled under gravity on earth, and that the growth responses of higher plants to microgravity conditions are regulated by both cell-wall mechanical properties and osmotic properties of stem cells.

  5. ETV REPORT - EVALUATION OF DAVIS TECHNOLOGIES INTERNATIONAL CORP. - INDUSTRIAL WASTEWATER TREATMENT PLANT

    EPA Science Inventory

    Abstract: Evaluation of Davis Technologies International Corp. Industrial Wastewater Treatment Plant

    The Davis Technologies International Corp. (DTIC) Industrial Wastewater Treatment Plant (IWTP) was tested, under actual production conditions, processing metalworking and ...

  6. Reactive Oxygen Species Generation-Scavenging and Signaling during Plant-Arbuscular Mycorrhizal and Piriformospora indica Interaction under Stress Condition

    PubMed Central

    Nath, Manoj; Bhatt, Deepesh; Prasad, Ram; Gill, Sarvajeet S.; Anjum, Naser A.; Tuteja, Narendra

    2016-01-01

    A defined balance between the generation and scavenging of reactive oxygen species (ROS) is essential to utilize ROS as an adaptive defense response of plants under biotic and abiotic stress conditions. Moreover, ROS are not only a major determinant of stress response but also act as signaling molecule that regulates various cellular processes including plant-microbe interaction. In particular, rhizosphere constitutes the biologically dynamic zone for plant–microbe interactions which forms a mutual link leading to reciprocal signaling in both the partners. Among plant–microbe interactions, symbiotic associations of arbuscular mycorrhizal fungi (AMF) and arbuscular mycorrhizal-like fungus especially Piriformospora indica with plants are well known to improve plant growth by alleviating the stress-impacts and consequently enhance the plant fitness. AMF and P. indica colonization mainly enhances ROS-metabolism, maintains ROS-homeostasis, and thereby averts higher ROS-level accrued inhibition in plant cellular processes and plant growth and survival under stressful environments. This article summarizes the major outcomes of the recent reports on the ROS-generation, scavenging and signaling in biotic-abiotic stressed plants with AMF and P. indica colonization. Overall, a detailed exploration of ROS-signature kinetics during plant-AMF/P. indica interaction can help in designing innovative strategies for improving plant health and productivity under stress conditions.

  7. From microgravity to osmotic conditions: mechanical integration of plant cells in response to stress

    NASA Astrophysics Data System (ADS)

    Wojtaszek, Przemyslaw; Kasprowicz, Anna; Michalak, Michal; Janczara, Renata; Volkmann, Dieter; Baluska, Frantisek

    Chemical reactions and interactions between molecules are commonly thought of as being at the basis of Life. Research of recent years, however, is more and more evidently indicating that physical forces are profoundly affecting the functioning of life at all levels of its organiza-tion. To detect and to respond to such forces, plant cells need to be integrated mechanically. Cell walls are the outermost functional zone of plant cells. They surround the individual cells, and also form a part of the apoplast. In cell suspensions, cell walls are embedded in the cul-ture medium which can be considered as a superapoplast. Through physical and chemical interactions they provide a basis for the structural and functional cell wall-plasma membrane-cytoskeleton (WMC) continuum spanning the whole cell. Here, the working of WMC contin-uum, and the participation of signalling molecules, like NO, would be presented in the context of plant responses to stress. In addition, the effects of the changing composition of WMC continuum will be considered, with particular attention paid to the modifications of the WMC components. Plant cells are normally adapted to changing osmotic conditions, resulting from variable wa-ter availability. The appearance of the osmotic stress activates adaptory mechanisms. If the strength of osmotic stress grows relatively slowly over longer period of time, the cells are able to adapt to conditions that are lethal to non-adapted cells. During stepwise adaptation of tobacco BY-2 suspension cells to the presence of various osmotically active agents, cells diverged into independent, osmoticum type-specific lines. In response to ionic agents (NaCl, KCl), the adhe-sive properties were increased and randomly dividing cells formed clumps, while cells adapted to nonionic osmotica (mannitol, sorbitol, PEG) revealed ordered pattern of precisely positioned cell divisions, resulting in the formation of long cell files. Changes in the growth patterns were accompanied by

  8. [HYGIENIC ASSESSMENT OFWORKING ENVIRONMENT FOR REPAIRERS OF RAILWAY ROLLING STOCK IN PLANT CONDITIONS].

    PubMed

    Sudeikina, N A; Kurenkova, G V

    2015-01-01

    The comprehensive hygienic assessment of working environment for main occupational groups Railway Car Repair Plant in factory conditions shows that workers are exposed to the impact of factors of chemical nature in concentrations exceeding maximum allowable (lead, manganese, alkali caustic, sulphuric and nitric acids, chromium trioxide, silicon-containing dust, white corundum, diiron trioxide, silicate-organic dust, wood and carbon dusts), the high level of noise, the local vibration, insufficient levels of artificial lighting. The manual work is used, that determines the high severity of the labor process in the most of workers. There was identified the inconsistency of quality and quantitative estimation of the work conditions on chemical factor at implementation of various types of control: certification of workplaces on work conditions, productions and state control. There was given an a priori evaluation of the occupational risk in the three main workshops, there were detected 13 occupations with mild (moderate) risk, 9 occupations with average (significant) risk, 6 professions with high (intolerable) risk category and 1 occupation--with very high (intolerable) risk category. Low indices of occupational diseases according to official statistics were establishedfail to be consistent with a high probability of their occurrence in the production. PMID:26856146

  9. [HYGIENIC ASSESSMENT OFWORKING ENVIRONMENT FOR REPAIRERS OF RAILWAY ROLLING STOCK IN PLANT CONDITIONS].

    PubMed

    Sudeikina, N A; Kurenkova, G V

    2015-01-01

    The comprehensive hygienic assessment of working environment for main occupational groups Railway Car Repair Plant in factory conditions shows that workers are exposed to the impact of factors of chemical nature in concentrations exceeding maximum allowable (lead, manganese, alkali caustic, sulphuric and nitric acids, chromium trioxide, silicon-containing dust, white corundum, diiron trioxide, silicate-organic dust, wood and carbon dusts), the high level of noise, the local vibration, insufficient levels of artificial lighting. The manual work is used, that determines the high severity of the labor process in the most of workers. There was identified the inconsistency of quality and quantitative estimation of the work conditions on chemical factor at implementation of various types of control: certification of workplaces on work conditions, productions and state control. There was given an a priori evaluation of the occupational risk in the three main workshops, there were detected 13 occupations with mild (moderate) risk, 9 occupations with average (significant) risk, 6 professions with high (intolerable) risk category and 1 occupation--with very high (intolerable) risk category. Low indices of occupational diseases according to official statistics were establishedfail to be consistent with a high probability of their occurrence in the production.

  10. High methylmercury production under ferruginous conditions in sediments impacted by sewage treatment plant discharges.

    PubMed

    Bravo, Andrea G; Bouchet, Sylvain; Guédron, Stéphane; Amouroux, David; Dominik, Janusz; Zopfi, Jakob

    2015-09-01

    Sewage treatment plants (STPs) are important point sources of mercury (Hg) to the environment. STPs are also significant sources of iron when hydrated ferric oxide (HFO) is used as a dephosphatation agent during water purification. In this study, we combined geochemical and microbiological characterization with Hg speciation and sediment amendments to evaluate the impact of STP's effluents on monomethylmercury (MMHg) production. The highest in-situ Hg methylation was found close to the discharge pipe in subsurface sediments enriched with Hg, organic matter, and iron. There, ferruginous conditions were prevailing with high concentrations of dissolved Fe(2+) and virtually no free sulfide in the porewater. Sediment incubations demonstrated that the high MMHg production close to the discharge was controlled by low demethylation yields. Inhibition of dissimilatory sulfate reduction with molybdate led to increased iron reduction rates and Hg-methylation, suggesting that sulfate-reducing bacteria (SRB) may not have been the main Hg methylators under these conditions. However, Hg methylation in sediments amended with amorphous Fe(III)-oxides was only slightly higher than control conditions. Thus, in addition to iron-reducing bacteria, other non-SRB most likely contributed to Hg methylation. Overall, this study highlights that sediments impacted by STP discharges can become local hot-spots for Hg methylation due to the combined inputs of i) Hg, ii) organic matter, which fuels bacterial activities and iii) iron, which keeps porewater sulfide concentration low and hence Hg bioavailable.

  11. Effectiveness of beneficial plant-microbe interactions under hypobaric and hypoxic conditions in an advanced life support system

    NASA Astrophysics Data System (ADS)

    MacIntyre, Olathe; Stasiak, Michael; Cottenie, Karl; Trevors, Jack; Dixon, Mike

    An assembled microbial community in the hydroponics solution of an advanced life support system may improve plant performance and productivity in three ways: (1) exclusion of plant pathogens from the initial community, (2) resistance to infection, and (3) plant-growth promotion. However, the plant production area is likely to have a hypobaric (low pressure) and hypoxic (low oxygen) atmosphere to reduce structural mass and atmosphere leakage, and these conditions may alter plant-microbe interactions. Plant performance and productivity of radish (Raphanus sativus L. cv. Cherry Bomb II) grown under hypobaric and hypoxic conditions were investigated at the University of Guelph's Controlled Environment Systems Research Facility. Changes in the microbial communities that routinely colonized the re-circulated nutrient solution, roots, and leaves of radishes in these experiments were quantified in terms of similarity in community composition, abundance of bacteria, and community diversity before and after exposure to hypobaric and hypoxic conditions relative to communities maintained at ambient growth conditions. The microbial succession was affected by extreme hypoxia (2 kPa oxygen partial pressure) while hypobaria as low as 10 kPa total pressure had little effect on microbial ecology. There were no correlations found between the physiological profile of these unintentional microbial communities and radish growth. The effects of hypobaric and hypoxic conditions on specific plant-microbe interactions need to be determined before beneficial gnotobiotic communities can be developed for use in space. The bacterial strains Tal 629 of Bradyrhizobium japonicum and WCS417 of Pseudomonas fluorescens, and the plant pathogen Fusarium oxysporum f. sp. raphani will be used in future experiments. B. japonicum Tal 629 promotes radish growth in hydroponics systems and P. fluorescens WCS417 induces systemic resistance to fusarium wilt (F. oxysporum f. sp. raphani) in radish under ambient

  12. a Study on the SAR Data Observation Time for the Classification of Planting Condition of Paddy Fields

    NASA Astrophysics Data System (ADS)

    Kimura, A.; Kondo, A.; Mochizuki, K.

    2016-06-01

    In recent years, cultivation methods of rice have been diversified due to the low cost of rice-growing techniques. For example, there is direct sowing of seed rice in paddy field in addition to the practice of usual paddy field to flooding at the time of planting. The yield of the usual paddy field and the direct sowing is different even though the same varieties are grown in the same area. It is necessary to grasp by performing classification for the usual paddy field or direct sowing for the management of agricultural crops. The main objective of this study was to select the observation time for the classification of paddy fields' planting conditions by utilizing Synthetic Aperture Radar TerraSAR-X satellite. The planting conditions included the usual planting of rice, the direct sowing of rice and the soybean. We selected the observation time by the statistical distance of the microwave backscattering in each paddy field for maximizing the planting condition classification. In addition, the satellite data observation timing considered the processing time of the analysis and the acquisition costs. The acquisition was performed 4 periods from 2 periods in the rice growing season and the planting phase. In the current study, we were able to classify the usual planting of rice, the direct sowing of rice and the soybean by TerraSAR-X data for the later planting of rice during mid-May and initial growth of rice in early June.

  13. Harvest index, a parameter conditioning responsiveness of wheat plants to elevated CO2

    PubMed Central

    Aranjuelo, Iker; Sanz-Sáez, Álvaro; Jauregui, Iván; Irigoyen, Juan J.; Araus, José L.; Sánchez-Díaz, Manuel; Erice, Gorka

    2013-01-01

    The expansion of the world’s population requires the development of high production agriculture. For this purpose, it is essential to identify target points conditioning crop responsiveness to predicted [CO2]. The aim of this study was to determine the relevance of ear sink strength in leaf protein and metabolomic profiles and its implications in photosynthetic activity and yield of durum wheat plants exposed to elevated [CO2]. For this purpose, a genotype with high harvest index (HI) (Triticum durum var. Sula) and another with low HI (Triticum durum var. Blanqueta) were exposed to elevated [CO2] (700 µmol mol–1 versus 400 µmol mol–1 CO2) in CO2 greenhouses. The obtained data highlighted that elevated [CO2] only increased plant growth in the genotype with the largest HI; Sula. Gas exchange analyses revealed that although exposure to 700 µmol mol–1 depleted Rubisco content, Sula was capable of increasing the light-saturated rate of CO2 assimilation (Asat) whereas, in Blanqueta, the carbohydrate imbalance induced the down-regulation of Asat. The specific depletion of Rubisco in both genotypes under elevated [CO2], together with the enhancement of other proteins in the Calvin cycle, revealed that there was a redistribution of N from Rubisco towards RuBP regeneration. Moreover, the down-regulation of N, NO3 –, amino acid, and organic acid content, together with the depletion of proteins involved in amino acid synthesis that was detected in Blanqueta grown at 700 µmol mol–1 CO2, revealed that inhibition of N assimilation was involved in the carbohydrate imbalance and consequently with the down-regulation of photosynthesis and growth in these plants. PMID:23564953

  14. Rapid in situ detection of alkaloids in plant tissue under ambient conditions using desorption electrospray ionization.

    PubMed

    Talaty, Nari; Takáts, Zoltán; Cooks, R Graham

    2005-12-01

    Desorption electrospray ionization (DESI) mass spectrometry is applied to the in situ detection of alkaloids in the tissue of poison hemlock (Conium maculatum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna). The experiment is carried out by electrospraying micro-droplets of solvent onto native or freshly-cut plant tissue surfaces. No sample preparation is required and the mass spectra are recorded under ambient conditions, in times of a few seconds. The impact of the sprayed droplets on the surface produces gaseous ions from organic compounds originally present in the plant tissue. The effects of operating parameters, including the electrospray high voltage, heated capillary temperature, the solvent infusion rate and the carrier gas pressure on analytical performance are evaluated and optimized. Different types of plant material are analyzed including seeds, stems, leaves, roots and flowers. All the previously reported alkaloids have been detected in C. maculatum, while fifteen out of nineteen known alkaloids for D. stramonium and the principal alkaloids of A. belladonna were also identified. All identifications were confirmed by tandem mass spectrometry. Results obtained show similar mass spectra, number of alkaloids, and signal intensities to those obtained when extraction and separation processes are performed prior to mass spectrometric analysis. Evidence is provided that DESI ionization occurs by both a gas-phase ionization process and by a droplet pick-up mechanism. Quantitative precision of DESI is compared with conventional electrospray ionization mass spectrometry (after sample workup) and the RSD values for the same set of 25 dicotyledonous C. maculatum seeds (one half of each seed analyzed by ESI and the other by DESI) are 9.8% and 5.2%, respectively.

  15. Light to liquid fuel: theoretical and realized energy conversion efficiency of plants using crassulacean acid metabolism (CAM) in arid conditions.

    PubMed

    Davis, Sarah C; LeBauer, David S; Long, Stephen P

    2014-07-01

    There has been little attention paid to crassulacean acid metabolism (CAM) as a mechanism for bioenergy crop tolerance to water limitation, in part, because potential yields of CAM plants have been assumed to be lower than those of most commonly studied bioenergy crops. The photochemical efficiency, water-use efficiency (WUE), biomass production, and fuel yield potentials of CAM, C3, and C4 plants that are considered or already in use for bioenergy are reviewed here. The theoretical photosynthetic efficiency of CAM plants can be similar to or greater than other photosynthetic pathways. In arid conditions, the greater WUE of CAM species results in theoretical biomass yield potentials that are 147% greater than C4 species. The realized yields of CAM plants are similar to the theoretical yields that account for water-limiting conditions. CAM plants can potentially be viable commercial bioenergy crops, but additional direct yield measurements from field trials of CAM species are still needed. PMID:24744431

  16. Optimisation potential for a SBR plant based upon integrated modelling for dry and wet weather conditions.

    PubMed

    Rönner-Holm, S G E; Kaufmann Alves, I; Steinmetz, H; Holm, N C

    2009-01-01

    Integrated dynamic simulation analysis of a full-scale municipal sequential batch reactor (SBR) wastewater treatment plant (WWTP) was performed using the KOSMO pollution load simulation model for the combined sewer system (CSS) and the ASM3 + EAWAG-BioP model for the WWTP. Various optimising strategies for dry and storm weather conditions were developed to raise the purification and hydraulic performance and to reduce operation costs based on simulation studies with the calibrated WWTP model. The implementation of some strategies on the plant led to lower effluent values and an average annual saving of 49,000 euro including sewage tax, which is 22% of the total running costs. Dynamic simulation analysis of CSS for an increased WWTP influent over a period of one year showed high potentials for reducing combined sewer overflow (CSO) volume by 18-27% and CSO loads for COD by 22%, NH(4)-N and P(total) by 33%. In addition, the SBR WWTP could easily handle much higher influents without exceeding the monitoring values. During the integrated simulation of representative storm events, the total emission load for COD dropped to 90%, the sewer system emitted 47% less, whereas the pollution load in the WWTP effluent increased to only 14% with 2% higher running costs.

  17. Sediment modification by seagrass beds: Muddification and sandification induced by plant cover and environmental conditions

    NASA Astrophysics Data System (ADS)

    van Katwijk, M. M.; Bos, A. R.; Hermus, D. C. R.; Suykerbuyk, W.

    2010-09-01

    Seagrasses are well-known ecosystem engineers. They reduce water dynamics and sediment resuspension, and trap fine sediments. However, exceptions of this paradigm have been reported. To test whether these exceptions could be related to plant cover and environmental conditions, we investigated sediment modification under influence of seagrass presence in various annual eelgrass ( Zostera marina) beds with varying plant cover and sediment composition. At the relatively wave-exposed, sandy sites, dense vegetation caused muddification (increase in fine sediments and organic content) of the sediments. Sparse vegetation (<35% cover) had no effect, as such confirming the classical sediment trapping paradigm. In contrast, at the sheltered sites with muddy sediments, dense vegetation had no effect on the sediment composition, and in sparse vegetation sandification (decrease in fine sediments and organic content) was recorded. Sandification was never recorded before and was probably related to turbulence enhancement. Both, muddification and sandification are likely to provide a feedback on seagrass performance. Muddification may increase the nutrient input and, depending on the nutrient status of the system, either stimulate or reduce seagrass development. Similarly, sandification may postpone and even prevent extinction of seagrass beds when it occurs in areas that may have become too muddy for seagrass growth.

  18. Methodology for reliability based condition assessment. Application to concrete structures in nuclear plants

    SciTech Connect

    Mori, Y.; Ellingwood, B.

    1993-08-01

    Structures in nuclear power plants may be exposed to aggressive environmental effects that cause their strength to decrease over an extended period of service. A major concern in evaluating the continued service for such structures is to ensure that in their current condition they are able to withstand future extreme load events during the intended service life with a level of reliability sufficient for public safety. This report describes a methodology to facilitate quantitative assessments of current and future structural reliability and performance of structures in nuclear power plants. This methodology takes into account the nature of past and future loads, and randomness in strength and in degradation resulting from environmental factors. An adaptive Monte Carlo simulation procedure is used to evaluate time-dependent system reliability. The time-dependent reliability is sensitive to the time-varying load characteristics and to the choice of initial strength and strength degradation models but not to correlation in component strengths within a system. Inspection/maintenance strategies are identified that minimize the expected future costs of keeping the failure probability of a structure at or below an established target failure probability during its anticipated service period.

  19. Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

    SciTech Connect

    Gillow, J.B.; Francis, A.

    2011-07-01

    Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid ({approx}70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

  20. The Agony of Choice: How Plants Balance Growth and Survival under Water-Limiting Conditions1

    PubMed Central

    Claeys, Hannes; Inzé, Dirk

    2013-01-01

    When confronted with water limitation, plants actively reprogram their metabolism and growth. Recently, it has become clear that growing tissues show specific and highly dynamic responses to drought, which differ from the well-studied responses in mature tissues. Here, we provide an overview of recent advances in understanding shoot growth regulation in water-limiting conditions. Of special interest is the balance between maintained growth and competitiveness on the one hand and ensured survival on the other hand. A number of master regulators controlling this balance have been identified, such as DELLAs and APETALA2/ETHYLENE RESPONSE FACTOR-type transcription factors. The possibilities of engineering or breeding crops that maintain growth in periods of mild drought, while still being able to activate protective tolerance mechanisms, are discussed. PMID:23766368

  1. Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States

    USGS Publications Warehouse

    Simkin, Samuel M.; Allen, Edith B.; Bowman, William D.; Clark, Christopher M.; Belnap, Jayne; Brooks, Matthew L.; Cade, Brian S.; Collins, Scott L.; Geiser, Linda H.; Gilliam, Frank S.; Jovan, Sarah E.; Pardo, Linda H.; Schulz, Bethany K.; Stevens, Carly J.; Suding, Katharine N.; Throop, Heather L.; Waller, Donald M.

    2016-01-01

    Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg N⋅ha−1⋅y−1, we found a unimodal relationship; richness increased at low deposition levels and decreased above 8.7 and 13.4 kg N⋅ha−1⋅y−1 in open and closed-canopy vegetation, respectively. N deposition exceeded critical loads for loss of plant species richness in 24% of 15,136 sites examined nationwide. There were negative relationships between species richness and N deposition in 36% of 44 community gradients. Vulnerability to N deposition was consistently higher in more acidic soils whereas the moderating roles of temperature and precipitation varied across scales. We demonstrate here that negative relationships between N deposition and species richness are common, albeit not universal, and that fine-scale processes can moderate vegetation responses to N deposition. Our results highlight the importance of contingent factors when estimating ecosystem vulnerability to N deposition and suggest that N deposition is affecting species richness in forested and nonforested systems across much of the continental United States.

  2. Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

    SciTech Connect

    Chen, W.W.; Gregonis, R.A.

    1997-08-01

    Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

  3. Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States

    PubMed Central

    Simkin, Samuel M.; Allen, Edith B.; Bowman, William D.; Clark, Christopher M.; Belnap, Jayne; Brooks, Matthew L.; Cade, Brian S.; Geiser, Linda H.; Gilliam, Frank S.; Jovan, Sarah E.; Pardo, Linda H.; Schulz, Bethany K.; Stevens, Carly J.; Suding, Katharine N.; Throop, Heather L.; Waller, Donald M.

    2016-01-01

    Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg N⋅ha−1⋅y−1, we found a unimodal relationship; richness increased at low deposition levels and decreased above 8.7 and 13.4 kg N⋅ha−1⋅y−1 in open and closed-canopy vegetation, respectively. N deposition exceeded critical loads for loss of plant species richness in 24% of 15,136 sites examined nationwide. There were negative relationships between species richness and N deposition in 36% of 44 community gradients. Vulnerability to N deposition was consistently higher in more acidic soils whereas the moderating roles of temperature and precipitation varied across scales. We demonstrate here that negative relationships between N deposition and species richness are common, albeit not universal, and that fine-scale processes can moderate vegetation responses to N deposition. Our results highlight the importance of contingent factors when estimating ecosystem vulnerability to N deposition and suggest that N deposition is affecting species richness in forested and nonforested systems across much of the continental United States. PMID:27035943

  4. Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States.

    PubMed

    Simkin, Samuel M; Allen, Edith B; Bowman, William D; Clark, Christopher M; Belnap, Jayne; Brooks, Matthew L; Cade, Brian S; Collins, Scott L; Geiser, Linda H; Gilliam, Frank S; Jovan, Sarah E; Pardo, Linda H; Schulz, Bethany K; Stevens, Carly J; Suding, Katharine N; Throop, Heather L; Waller, Donald M

    2016-04-12

    Atmospheric nitrogen (N) deposition has been shown to decrease plant species richness along regional deposition gradients in Europe and in experimental manipulations. However, the general response of species richness to N deposition across different vegetation types, soil conditions, and climates remains largely unknown even though responses may be contingent on these environmental factors. We assessed the effect of N deposition on herbaceous richness for 15,136 forest, woodland, shrubland, and grassland sites across the continental United States, to address how edaphic and climatic conditions altered vulnerability to this stressor. In our dataset, with N deposition ranging from 1 to 19 kg N⋅ha(-1)⋅y(-1), we found a unimodal relationship; richness increased at low deposition levels and decreased above 8.7 and 13.4 kg N⋅ha(-1)⋅y(-1) in open and closed-canopy vegetation, respectively. N deposition exceeded critical loads for loss of plant species richness in 24% of 15,136 sites examined nationwide. There were negative relationships between species richness and N deposition in 36% of 44 community gradients. Vulnerability to N deposition was consistently higher in more acidic soils whereas the moderating roles of temperature and precipitation varied across scales. We demonstrate here that negative relationships between N deposition and species richness are common, albeit not universal, and that fine-scale processes can moderate vegetation responses to N deposition. Our results highlight the importance of contingent factors when estimating ecosystem vulnerability to N deposition and suggest that N deposition is affecting species richness in forested and nonforested systems across much of the continental United States. PMID:27035943

  5. Phenological mismatch with abiotic conditions implications for flowering in Arctic plants.

    PubMed

    Wheeler, Helen C; Høye, Toke T; Schmidt, Niels Martin; Svenning, Jens-Christian; Forchhammer, Mads C

    2015-03-01

    Although many studies have examined the phenological mismatches between interacting organisms, few have addressed the potential for mismatches between phenology and seasonal weather conditions. In the Arctic, rapid phenological changes in many taxa are occurring in association with earlier snowmelt. The timing of snowmelt is jointly affected by the size of the late winter snowpack and the temperature during the spring thaw. Increased winter snowpack results in delayed snowmelt, whereas higher air temperatures and faster snowmelt advance the timing of snowmelt. Where interannual variation in snowpack is substantial, changes in the timing of snowmelt can be largely uncoupled from changes in air temperature. Using detailed, long-term data on the flowering phenology of four arctic plant species from Zackenberg, Greenland, we investigate whether there is a phenological component to the temperature conditions experienced prior to and during flowering. In particular, we assess the role of timing of flowering in determining pre-flowering exposure to freezing temperatures and to the temperatures-experienced prior to flowering. We then examine the implications of flowering phenology for flower abundance. Earlier snowmelt resulted in greater exposure to freezing conditions, suggesting an increased potential for a mismatch between the timing of flowering and seasonal weather conditions and an increased potential for negative consequences, such as freezing 'damage. We also found a parabolic relationship between the timing of flowering and the temperature experienced during flowering after taking interannual temperature effects into account. If timing of flowering advances to a cooler period of the growing season, this may moderate the effects of a general warming trend across years. Flower abundance was quadratically associated with the timing of flowering, such that both early and late flowering led to lower flower abundance than did intermediate flowering. Our results

  6. Aging and condition monitoring of electric cables in nuclear power plants

    SciTech Connect

    Lofaro, R.J.; Grove, E.; Soo, P.

    1998-05-01

    There are a variety of environmental stressors in nuclear power plants that can influence the aging rate of components; these include elevated temperatures, high radiation fields, and humid conditions. Exposure to these stressors over long periods of time can cause degradation of components that may go undetected unless the aging mechanisms are identified and monitored. In some cases the degradation may be mitigated by maintenance or replacement. However, some components receive neither and are thus more susceptible to aging degradation, which might lead to failure. One class of components that falls in this category is electric cables. Cables are very often overlooked in aging analyses since they are passive components that require no maintenance. However, they are very important components since they provide power to safety related equipment and transmit signals to and from instruments and controls. This paper will look at the various aging mechanisms and failure modes associated with electric cables. Condition monitoring techniques that may be useful for monitoring degradation of cables will also be discussed.

  7. Microbial inoculants and organic amendment improves plant establishment and soil rehabilitation under semiarid conditions.

    PubMed

    Mengual, Carmen; Schoebitz, Mauricio; Azcón, Rosario; Roldán, Antonio

    2014-02-15

    The re-establishment of autochthonous shrub species is an essential strategy for recovering degraded soils under semiarid Mediterranean conditions. A field assay was carried out to determine the combined effects of the inoculation with native rhizobacteria (Bacillus megaterium, Enterobacter sp, Bacillus thuringiensis and Bacillus sp) and the addition of composted sugar beet (SB) residue on physicochemical soil properties and Lavandula dentata L. establishment. One year after planting, Bacillus sp. and B. megaterium + SB were the most effective treatments for increasing shoot dry biomass (by 5-fold with respect to control) and Enterobacter sp + SB was the most effective treatments for increasing dry root biomass. All the treatments evaluated significantly increased the foliar nutrient content (NPK) compared to control values (except B. thuringiensis + SB). The organic amendment had significantly increased available phosphorus content in rhizosphere soil by 29% respect to the control. Enterobacter sp combined with sugar beet residue improved total N content in soil (by 46% respect to the control) as well as microbiological and biochemical properties. The selection of the most efficient rhizobacteria strains and their combined effect with organic residue seems to be a critical point that drives the effectiveness of using these biotechnological tools for the revegetation and rehabilitation of degraded soils under semiarid conditions. PMID:24463051

  8. Starch Accumulation in the Bundle Sheaths of C3 Plants: A Possible Pre-Condition for C4 Photosynthesis.

    PubMed

    Miyake, Hiroshi

    2016-05-01

    C4 plants have evolved >60 times from their C3 ancestors. C4 photosynthesis requires a set of closely co-ordinated anatomical and biochemical characteristics. However, it is now recognized that the evolution of C4 plants requires fewer changes than had ever been considered, because of the genetic, biochemical and anatomical pre-conditions of C3 ancestors that were recruited into C4 photosynthesis. Therefore, the pre-conditions in C3 plants are now being actively investigated to clarify the evolutionary trajectory from C3 to C4 plants and to engineer C4 traits efficiently into C3 crops. In the present mini review, the anatomical characteristics of C3 and C4 plants are briefly reviewed and the importance of the bundle sheath for the evolution of C4 photosynthesis is described. For example, while the bundle sheath of C3 rice plants accumulates large amounts of starch in the developing leaf blade and at the lamina joint of the mature leaf, the starch sheath function is also observed during leaf development in starch accumulator grasses regardless of photosynthetic type. The starch sheath function of C3 plants is therefore also implicated as a possible pre-condition for the evolution of C4 photosynthesis. The phylogenetic relationships between the types of storage carbohydrates and of photosynthesis need to be clarified in the future. PMID:26936788

  9. Evaluation of arbuscular mycorrhizal fungi capacity to alleviate abiotic stress of olive (Olea europaea L.) plants at different transplant conditions.

    PubMed

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth.

  10. Evaluation of Arbuscular Mycorrhizal Fungi Capacity to Alleviate Abiotic Stress of Olive (Olea europaea L.) Plants at Different Transplant Conditions

    PubMed Central

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth. PMID:24688382

  11. Evaluation of arbuscular mycorrhizal fungi capacity to alleviate abiotic stress of olive (Olea europaea L.) plants at different transplant conditions.

    PubMed

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth. PMID:24688382

  12. Linguistic Theory and Actual Language.

    ERIC Educational Resources Information Center

    Segerdahl, Par

    1995-01-01

    Examines Noam Chomsky's (1957) discussion of "grammaticalness" and the role of linguistics in the "correct" way of speaking and writing. It is argued that the concern of linguistics with the tools of grammar has resulted in confusion, with the tools becoming mixed up with the actual language, thereby becoming the central element in a metaphysical…

  13. El Observatorio Gemini - Status actual

    NASA Astrophysics Data System (ADS)

    Levato, H.

    Se hace una breve descripción de la situación actual del Observatorio Gemini y de las últimas decisiones del Board para incrementar la eficiencia operativa. Se hace también una breve referencia al uso argentino del observatorio.

  14. Modulation of antioxidant machinery in α-tocopherol-enriched transgenic Brassica juncea plants tolerant to abiotic stress conditions.

    PubMed

    Kumar, Deepak; Yusuf, Mohd Aslam; Singh, Preeti; Sardar, Meryam; Sarin, Neera Bhalla

    2013-10-01

    The antioxidant machinery in plants consists of several components with unique or overlapping functions that combat the deleterious production of reactive oxygen species (ROS) induced by stress conditions. Tocopherols are a group of powerful antioxidants having additional roles in signaling and gene expression, with α-tocopherol being the most potent form. In the present study, we used wild-type (WT) and α-tocopherol-enriched transgenic (TR) Brassica juncea plants grown under salt, heavy metal, and osmotic stress to compare their relative tolerance to these stresses and to assess the effects of increased α-tocopherol content on the other antioxidative enzymes and molecules. The oxidative damage caused by induced stress was lower in TR plants compared to WT plants as assessed by their higher relative water content and lower electrolyte leakage, malondialdehyde content as well as H(2)O(2) accumulation. Lesser superoxide and H(2)O(2) accumulation was also observed by histochemical staining in TR seedlings exposed to stress. Though no significant differences were evident under normal growth conditions, TR plants showed higher activities and transcript levels of antioxidant enzymes superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase than WT plants under similar stress conditions. A decrease in ascorbate and glutathione content with marginally higher reductive ratios of these compounds was also observed in TR plants under the stress conditions. Our findings implicate the role of higher α-tocopherol levels in conferring better tolerance against salt, heavy metal, and osmotic stresses and also establish the existence of interplay between this lipid-soluble antioxidant and other water-soluble components of plant antioxidant defense.

  15. Protection of turmeric plants from rhizome rot disease under field conditions by β-D-glucan nanoparticle.

    PubMed

    Anusuya, Sathiyanarayanan; Sathiyabama, Muthukrishnan

    2015-01-01

    The rhizome rot caused by Pythium aphanidermatum is one of the most devastating diseases of the turmeric crop. Fungicides are unable to control the rapidly evolving P. aphanidermatum and new control strategies are urgently needed. This study examined the effect of β-d-glucan nanoparticles (GNP) in turmeric plants under field condition by the foliar spray method. Enhanced plant growth, rhizome yield, and curcumin content demonstrate the positive effect of the GNP on turmeric plants. Rapid activation of various defense enzymes was also observed in leaves and rhizomes of treated plants. GNP-treated plants showed a decreased rot incidence. It may be possible that increased defense enzymes might have played a role in reducing the colonization of pathogen.

  16. Ecological and evolutionary conditions for fruit abortion to regulate pollinating seed-eaters and increase plant reproduction.

    PubMed

    Holland, J Nathaniel; DeAngelis, Donald L

    2002-05-01

    Coevolved mutualisms, such as those between senita cacti, yuccas, and their respective obligate pollinators, benefit both species involved in the interaction. However, in these pollination mutualisms the pollinator's larvae impose a cost on plants through consumption of developing seeds and fruit. The effects of pollinators on benefits and costs are expected to vary with the abundance of pollinators, because large population sizes result in more eggs and larval seed-eaters. Here, we develop the hypothesis that fruit abortion, which is common in yucca, senita, and plants in general, could in some cases have the function of limiting pollinator abundance and, thereby, increasing fruit production. Using a general steady-state model of fruit production and pollinator dynamics, we demonstrate that plants involved in pollinating seed-eater mutualisms can increase their fecundity by randomly aborting fruit. We show that the ecological conditions under which fruit abortion can improve plants fecundity are not unusual. They are best met when the plant is long-lived, the population dynamics of the pollinator are much faster than those of the plant, the loss of one fruit via abortion kills a larva that would have the expectation of destroying more than one fruit through its future egg laying as an adult moth, and the effects of fruit abortion on pollinator abundance are spatially localized. We then use the approach of adaptive dynamics to find conditions under which a fruit abortion strategy based on regulating the pollinator population could feasibly evolve in this type of plant-pollinator interaction.

  17. Fossil Plants As Proxies For Climate Change In The Tropics During Greenhouse To Icehouse And Icehouse To Greenhouse Conditions During The Late Paleozoic

    NASA Astrophysics Data System (ADS)

    Pfefferkorn, H. W.; Gastaldo, R. A.; DiMichele, W. A.

    2011-12-01

    Vascular plants first experienced the effects of major glaciation during the Carboniferous (glaciation ~ 326 to 305 million years ago). The response of tropical vegetation to these climatic fluctuations, especially the transitions from greenhouse to icehouse conditions (ice age sensu lato) and back to warm times, can now be characterized based on results from large paleobotanical data sets originally collected to solve stratigraphic and paleoecologic questions. The data come from North America and central Europe, which at that time were part of a single continent situated in the tropics. At the onset of icehouse conditions innovation (species origination) occurred in ever-wet climates and environments, while floras in drier environments were still dominated by holdovers/survivors. The changes that did occur happened step-wise spread over a significant time. During the height of the ice age, glacial-interglacial cycles produced large sea-level fluctuations, and concomitant climatic changes, so that significant areas of continents in the tropics were alternately covered by shallow seas or densely vegetated terrestrial environments. In spite of the repeated destruction of wet lowland habitats during each transgression of the sea, most of the species and the basic configuration of the plant communities in the wetland biome returned again and again. This resilience demonstrates that glacial-interglacial cycles by themselves do not produce extirpations or extinctions. Actually, the Carboniferous icehouse time has the lowest values for extinctions or originations. At the transition from icehouse to greenhouse conditions evolutionary innovation was occurring on a major scale in dry environments while wet environments retained their "conservative" species make up. Thus, environmental threshold-crossing marked both the beginning and end of this cold interval, and produced extinctions and innovation, although a reversal is seen in the environments that support innovation at

  18. Structural safety analysis based on seismic service conditions for butterfly valves in a nuclear power plant.

    PubMed

    Han, Sang-Uk; Ahn, Dae-Gyun; Lee, Myeong-Gon; Lee, Kwon-Hee; Han, Seung-Ho

    2014-01-01

    The structural integrity of valves that are used to control cooling waters in the primary coolant loop that prevents boiling within the reactor in a nuclear power plant must be capable of withstanding earthquakes or other dangerous situations. In this study, numerical analyses using a finite element method, that is, static and dynamic analyses according to the rigid or flexible characteristics of the dynamic properties of a 200A butterfly valve, were performed according to the KEPIC MFA. An experimental vibration test was also carried out in order to verify the results from the modal analysis, in which a validated finite element model was obtained via a model-updating method that considers changes in the in situ experimental data. By using a validated finite element model, the equivalent static load under SSE conditions stipulated by the KEPIC MFA gave a stress of 135 MPa that occurred at the connections of the stem and body. A larger stress of 183 MPa was induced when we used a CQC method with a design response spectrum that uses 2% damping ratio. These values were lower than the allowable strength of the materials used for manufacturing the butterfly valve, and, therefore, its structural safety met the KEPIC MFA requirements.

  19. Dynamic Response of Large Wind Power Plant Affected by Diverse Conditions at Individual Turbines

    SciTech Connect

    Elizondo, Marcelo A.; Lu, Shuai; Lin, Guang; Wang, Shaobu

    2014-07-31

    Diverse operating conditions at individual wind turbine generators (WTG) within wind power plants (WPPs) can affect the WPP dynamic response to system faults. For example, individual WTGs can experience diverse terminal voltage and power output caused by different wind direction and speed, affecting the response of protection and control limiters. In this paper, we present a study to investigate the dynamic response of a detailed WPP model under diverse power outputs of its individual WTGs. Wake effect is considered as the reason for diverse power outputs. The diverse WTG power output is evaluated in a test system where a large 168-machine test WPP is connected to the IEEE-39-bus system. The power output from each WTG is derived from a wake effect model that uses realistic statistical data for incoming wind speed and direction. The results show that diverse WTG output due to wake effect can affect the WPP dynamic response activating specialized control in some turbines. In addition, transient stability is affected by exhibiting uncertainty in critical clearing time calculation.

  20. Placement of the radiochemical processing plant at Oak Ridge National Laboratory into a safe standby condition

    SciTech Connect

    Holladay, D.W.; Bopp, C.D.; Farmer, A.J.; Johnson, J.K.; Miller, C.H.; Powers, B.A.; Collins, E.D.

    1986-01-01

    Extensive upgrade, cleanup, and decontamination efforts are being conducted for appropriate areas in the Radiochemical Processing Plant (RPP) with the goal of achieving ''safe standby'' condition by the end of FY 1989. The ventilation system must maintain containment; thus, it is being upgraded via demolition and replacement of marginally adequate ductwork, fans, and control systems. Areas that are being decontaminated and stripped of various services (e.g., piping, ductwork, and process tanks) include hot cells, makeup rooms, and pipe tunnels. Operating equipment that is being decontaminated includes glove boxes and hoods. Replacement of the ventilation system and removal of equipment from pipe tunnels, cells, and makeup rooms are accomplished by contact labor by workers using proper attire, safety rules, and shielding. Removal of contaminated ductwork and piping is conducted with containment enclosures that are strategically located at breakpoints, and methods of separation are chosen to conform with health physics requirements. The methods of cutting contaminated piping and ductwork include portable reciprocating saws, pipe cutters, burning, and plasma torch. Specially designed containment enclosures will be used to prevent the spread of radioactive contamination while maintaining adequate ventilation. 6 figs.

  1. Structural Safety Analysis Based on Seismic Service Conditions for Butterfly Valves in a Nuclear Power Plant

    PubMed Central

    Han, Sang-Uk; Ahn, Dae-Gyun; Lee, Myeong-Gon

    2014-01-01

    The structural integrity of valves that are used to control cooling waters in the primary coolant loop that prevents boiling within the reactor in a nuclear power plant must be capable of withstanding earthquakes or other dangerous situations. In this study, numerical analyses using a finite element method, that is, static and dynamic analyses according to the rigid or flexible characteristics of the dynamic properties of a 200A butterfly valve, were performed according to the KEPIC MFA. An experimental vibration test was also carried out in order to verify the results from the modal analysis, in which a validated finite element model was obtained via a model-updating method that considers changes in the in situ experimental data. By using a validated finite element model, the equivalent static load under SSE conditions stipulated by the KEPIC MFA gave a stress of 135 MPa that occurred at the connections of the stem and body. A larger stress of 183 MPa was induced when we used a CQC method with a design response spectrum that uses 2% damping ratio. These values were lower than the allowable strength of the materials used for manufacturing the butterfly valve, and, therefore, its structural safety met the KEPIC MFA requirements. PMID:24955416

  2. A conditionally dispensable chromosome controls host-specific pathogenicity in the fungal plant pathogen Alternaria alternata.

    PubMed Central

    Hatta, Rieko; Ito, Kaoru; Hosaki, Yoshitsugu; Tanaka, Takayoshi; Tanaka, Aiko; Yamamoto, Mikihiro; Akimitsu, Kazuya; Tsuge, Takashi

    2002-01-01

    The filamentous fungus Alternaria alternata contains seven pathogenic variants (pathotypes), which produce host-specific toxins and cause diseases on different plants. Previously, the gene cluster involved in host-specific AK-toxin biosynthesis of the Japanese pear pathotype was isolated, and four genes, named AKT genes, were identified. The AKT homologs were also found in the strawberry and tangerine pathotypes, which produce AF-toxin and ACT-toxin, respectively. This result is consistent with the fact that the toxins of these pathotypes share a common 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid structural moiety. In this study, three of the AKT homologs (AFT1-1, AFTR-1, and AFT3-1) were isolated on a single cosmid clone from strain NAF8 of the strawberry pathotype. In NAF8, all of the AKT homologs were present in multiple copies on a 1.05-Mb chromosome. Transformation-mediated targeting of AFT1-1 and AFT3-1 in NAF8 produced AF-toxin-minus, nonpathogenic mutants. All of the mutants lacked the 1.05-Mb chromosome encoding the AFT genes. This chromosome was not essential for saprophytic growth of this pathogen. Thus, we propose that a conditionally dispensable chromosome controls host-specific pathogenicity of this pathogen. PMID:12019223

  3. Salt marsh dieback in coastal Louisiana: survey of plant and soil conditions in Barataria and Terrebonne basins, June 2000-September 2001

    USGS Publications Warehouse

    McKee, Karen L.; Mendelssohn, Irving A.; Materne, Michael D.

    2006-01-01

    Sudden and extensive dieback of the perennial marsh grass, Spartina alterniflora Loisel (smooth cordgrass), which dominates regularly flooded salt marshes along the Gulf of Mexico and Atlantic coastlines, occurred in the coastal zone of Louisiana. The objectives of this study were to assess soil and plant conditions in dieback areas of the Barataria-Terrebonne estuarine system as well as vegetative recovery during and after this dieback event. Multiple dieback sites were examined along 100 km of shoreline from the Atchafalaya River to the Mississippi River during the period from June 2000 through September 2001. The species primarily affected was S. alterniflora; sympatric species such as Avicennia germinans (L.) Stearn (black mangrove) and Juncus roemerianus Scheele (needlegrass rush) showed no visible signs of stress. The pattern of marsh dieback was distinctive with greatest mortality in the marsh interior, suggesting a correlation with local patterns of soil chemistry and/or hydrology. Little or no expansion of dieback occurred subsequent to the initial event, and areas with 50 percent or less mortality in the fall of 2000 had completely recovered by April 2001. Recovery was slower in interior marshes with 90 percent or greater mortality initially. However, regenerating plants in dieback areas showing some recovery were robust, and reproductive output was high, indicating that the causative agent was no longer present and that post-dieback soil conditions were actually promoting plant growth. Stands of other species within or near some dieback sites remained largely unchanged or expanded (A. germinans) into the dead salt marsh. The cause of the dieback is currently unknown. Biotic agents and excessive soil waterlogging/high sulfide were ruled out as primary causes of this acute event, although they could have contributed to overall plant stress and/or interacted with the primary agent to cause plant mortality. Our observations over the 15 month study

  4. AN APPROACH TO ASSESSING THE CONDITION OF RIPARIAN PLANT COMMUNITIES IN THE JOHN DAY AND DESCHUTES RIVER BASINS OF EASTERN OREGON

    EPA Science Inventory

    Riparian vegetation represents unique plant communities and provides a variety of ecosystem services that influence in-stream condition. This research develops methods and indicators for evaluating vegetation condition. A key indicator of riparian vegetation condition is the deg...

  5. Comment on 'Shang S. 2012. Calculating actual crop evapotranspiration under soil water stress conditions with appropriate numerical methods and time step. Hydrological Processes 26: 3338-3343. DOI: 10.1002/hyp.8405'

    NASA Technical Reports Server (NTRS)

    Yatheendradas, Soni; Narapusetty, Balachandrudu; Peters-Lidard, Christa; Funk, Christopher; Verdin, James

    2014-01-01

    A previous study analyzed errors in the numerical calculation of actual crop evapotranspiration (ET(sub a)) under soil water stress. Assuming no irrigation or precipitation, it constructed equations for ET(sub a) over limited soil-water ranges in a root zone drying out due to evapotranspiration. It then used a single crop-soil composite to provide recommendations about the appropriate usage of numerical methods under different values of the time step and the maximum crop evapotranspiration (ET(sub c)). This comment reformulates those ET(sub a) equations for applicability over the full range of soil water values, revealing a dependence of the relative error in numerical ET(sub a) on the initial soil water that was not seen in the previous study. It is shown that the recommendations based on a single crop-soil composite can be invalid for other crop-soil composites. Finally, a consideration of the numerical error in the time-cumulative value of ET(sub a) is discussed besides the existing consideration of that error over individual time steps as done in the previous study. This cumulative ET(sub a) is more relevant to the final crop yield.

  6. Impact of hormonal crosstalk on plant resistance and fitness under multi-attacker conditions

    PubMed Central

    Vos, Irene A.; Moritz, Liselotte; Pieterse, Corné M. J.; Van Wees, Saskia C. M.

    2015-01-01

    The hormone salicylic acid (SA) generally induces plant defenses against biotrophic pathogens. Jasmonic acid (JA) and its oxylipin derivatives together with ethylene (ET) are generally important hormonal regulators of induced plant defenses against necrotrophic pathogens, whereas JAs together with abscisic acid (ABA) are implicated in induced plant defenses against herbivorous insects. Hormonal crosstalk between the different plant defense pathways has often been hypothesized to be a cost-saving strategy that has evolved as a means of the plant to reduce allocation costs by repression of unnecessary defenses, thereby minimizing trade-offs between plant defense and growth. However, proof for this hypothesis has not been demonstrated yet. In this study the impact of hormonal crosstalk on disease resistance and fitness of Arabidopsis thaliana when under multi-species attack was investigated. Induction of SA- or JA/ABA-dependent defense responses by the biotrophic pathogen Hyaloperonospora arabidopsidis or the herbivorous insect Pieris rapae, respectively, was shown to reduce the level of induced JA/ET-dependent defense against subsequent infection with the necrotrophic pathogen Botrytis cinerea. However, despite the enhanced susceptibility to this second attacker, no additional long-term negative effects were observed on plant fitness when plants had been challenged by multiple attackers. Similarly, when plants were grown in dense competition stands to enlarge fitness effects of induced defenses, treatment with a combination of SA and MeJA did not cause additional negative effects on plant fitness in comparison to the single MeJA treatment. Together, these data support the notion that hormonal crosstalk in plants during multi-attacker interactions allows plants to prioritize their defenses, while limiting the fitness costs associated with induction of defenses. PMID:26347758

  7. Ecological and evolutionary conditions for fruit abortion to regulate pollinating seed-eaters and increase plant production

    USGS Publications Warehouse

    Holland, J. Nathaniel; DeAngelis, Donald L.

    2002-01-01

    Coevolved mutualisms, such as those between senita cacti, yuccas, and their respective obligate pollinators, benefit both species involved in the interaction. However, in these pollination mutualisms the pollinator's larvae impose a cost on plants through consumption of developing seeds and fruit. The effects of pollinators on benefits and costs are expected to vary with the abundance of pollinators, because large population sizes result in more eggs and larval seed-eaters. Here, we develop the hypothesis that fruit abortion, which is common in yucca, senita, and plants in general, could in some cases have the function of limiting pollinator abundance and, thereby, increasing fruit production. Using a general steady-state model of fruit production and pollinator dynamics, we demonstrate that plants involved in pollinating seed-eater mutualisms can increase their fecundity by randomly aborting fruit. We show that the ecological conditions under which fruit abortion can improve plants fecundity are not unusual. They are best met when the plant is long-lived, the population dynamics of the pollinator are much faster than those of the plant, the loss of one fruit via abortion kills a larva that would have the expectation of destroying more than one fruit through its future egg laying as an adult moth, and the effects of fruit abortion on pollinator abundance are spatially localized. We then use the approach of adaptive dynamics to find conditions under which a fruit abortion strategy based on regulating the pollinator population could feasibly evolve in this type of plant–pollinator interaction.

  8. Predicting Plant Performance Under Simultaneously Changing Environmental Conditions-The Interplay Between Temperature, Light, and Internode Growth.

    PubMed

    Kahlen, Katrin; Chen, Tsu-Wei

    2015-01-01

    Plant performance is significantly influenced by prevailing light and temperature conditions during plant growth and development. For plants exposed to natural fluctuations in abiotic environmental conditions it is however laborious and cumbersome to experimentally assign any contribution of individual environmental factors to plant responses. This study aimed at analyzing the interplay between light, temperature and internode growth based on model approaches. We extended the light-sensitive virtual plant model L-Cucumber by implementing a common Arrhenius function for appearance rates, growth rates, and growth durations. For two greenhouse experiments, the temperature-sensitive model approach resulted in a precise prediction of cucumber mean internode lengths and number of internodes, as well as in accurately predicted patterns of individual internode lengths along the main stem. In addition, a system's analysis revealed that environmental data averaged over the experimental period were not necessarily related to internode performance. Finally, the need for a species-specific parameterization of the temperature response function and related aspects in modeling temperature effects on plant development and growth is discussed.

  9. Assessment of potential doses to workers during postulated accident conditions at the Waste Isolation Pilot Plant

    SciTech Connect

    Hoover, M.D.; Farrell, R.F.; Newton, G.J.

    1995-12-01

    The recent 1995 WIPP Safety Analysis Report (SAR) Update provided detailed analyses of potential radiation doses to members of the public at the site boundary during postulated accident scenarios at the U.S. Department of Energy`s Waste Isolation Pilot Plant (WIPP). The SAR Update addressed the complete spectrum of potential accidents associated with handling and emplacing transuranic waste at WIPP, including damage to waste drums from fires, punctures, drops, and other disruptions. The report focused on the adequacy of the multiple layers of safety practice ({open_quotes}defense-in-depth{close_quotes}) at WIPP, which are designed to (1) reduce the likelihood of accidents and (2) limit the consequences of those accidents. The safeguards which contribute to defense-in-depth at WIPP include a substantial array of inherent design features, engineered controls, and administrative procedures. The SAR Update confirmed that the defense-in-depth at WIPP is adequate to assure the protection of the public and environment. As a supplement to the 1995 SAR Update, we have conducted additional analyses to confirm that these controls will also provide adequate protection to workers at the WIPP. The approaches and results of the worker dose assessment are summarized here. In conformance with the guidance of DOE Standard 3009-94, we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposures under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR Update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, members of the public, and the environment.

  10. Microbial gas generation under expected Waste Isolation Pilot Plant repository conditions

    SciTech Connect

    Francis, A.J.; Gillow, J.B.; Giles, M.R.

    1997-03-01

    Gas generation from the microbial degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository was investigated at Brookhaven National Laboratory. The biodegradation of mixed cellulosics (various types of paper) and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, neoprene, hypalon, and leaded hypalon) was examined. The rate of gas production from cellulose biodegradation in inundated samples incubated for 1,228 days at 30 C was biphasic, with an initial rapid rate up to approximately 600 days incubation, followed by a slower rate. The rate of total gas production in anaerobic samples containing mixed inoculum was as follows: 0.002 mL/g cellulose/day without nutrients; 0.004 mL/g cellulose/day with nutrients; and 0.01 mL/g cellulose/day in the presence of excess nitrate. Carbon dioxide production proceeded at a rate of 0.009 {micro}mol/g cellulose/day in anaerobic samples without nutrients, 0.05 {micro}mol/g cellulose/day in the presence of nutrients, and 0.2 {micro}mol/g cellulose/day with excess nitrate. Adding nutrients and excess nitrate stimulated denitrification, as evidenced by the accumulation of N{sub 2}O in the headspace (200 {micro}mol/g cellulose). The addition of the potential backfill bentonite increased the rate of CO{sub 2} production to 0.3 {micro}mol/g cellulose/day in anaerobic samples with excess nitrate. Analysis of the solution showed that lactic, acetic, propionic, butyric, and valeric acids were produced due to cellulose degradation. Samples incubated under anaerobic humid conditions for 415 days produced CO{sub 2} at a rate of 0.2 {micro}mol/g cellulose/day in the absence of nutrients, and 1 {micro}mol/g cellulose/day in the presence of bentonite and nutrients. There was no evidence of biodegradation of electron-beam irradiated plastic and rubber.

  11. Biological effects of weightlessness and clinostatic conditions registered in cells of root meristem and cap of higher plants

    NASA Astrophysics Data System (ADS)

    Sytnik, K. M.; Kordyum, E. L.; Belyavskaya, N. A.; Nedukha, E. M.; Tarasenko, V. A.

    Research in cellular reproduction, differentiation and vital activity, i.e. processes underlying the development and functioning of organisms, plants included, is essential for solving fundamental and applied problems of space biology. Detailed anatomical analysis of roots of higher plants grown on board the Salyut 6 orbital research station show that under conditions of weightlessness for defined duration mitosis, cytokinesis and tissue differentiation in plant vegetative organs occur essentially normally. At the same time, certain rearrangements in the structural organization of cellular organelles - mainly the plastid apparatus, mitochondria, Golgi apparatus and nucleus - are established in the root meristem and cap of the experimental plants. This is evidence for considerable changes in cellular metabolism. The structural changes in the subcellular level arising under spaceflight conditions are partially absent in clinostat experiments designed to simulate weightlessness. Various clinostatic conditions have different influences on the cell structural and functional organization than does space flight. It is suggested that alterations of cellular metabolism under weightlessness and clinostatic conditions occur within existing genetic programs.

  12. The Capability of Several Toxic Plants to Condition Taste Aversions in Sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing livestock frequently ingest toxic plants, occasionally with fatal results. Behavioral adjustments by livestock may reduce toxin intake; for example they can develop food aversions which may protect animals from over-ingestion of toxic plants. The purpose of this study was to evaluate three...

  13. Chromosomes and plant cell division in space: environmental conditions and experimental details.

    PubMed

    Levine, H G; Krikorian, A D

    1992-01-01

    Details of the plant cultivation system developed for the CHROMEX experiment flown aboard the Shuttle Discovery (March, 1989) in NASA's Plant Growth Unit (PGU) are presented. The physical regime as measured during Spaceflight, both within the orbiter cabin environment and within the PGU itself, is discussed. These data function as a guide to what may be representative of the environmental regime in which Space-based plant cultivation systems will be operating, at least for the near-term. Attention is also given to practical considerations involved in conducting a plant experiment in Space. Of particular importance are the differences expected to occur in moisture distribution patterns within substrates used to cultivate plants in Space vs on Earth.

  14. Fiber optic spectrophotometry monitoring of plant nutrient deficiency under hydroponic culture conditions

    NASA Astrophysics Data System (ADS)

    Liew, Oi Wah; Boey, William S. L.; Asundi, Anand K.; Chen, Jun-Wei; He, Duo-Min

    1999-05-01

    In this paper, fiber optic spectrophotometry (FOSpectr) was adapted to provide early detection of plant nutrient deficiency by measuring leaf spectral reflectance variation resulting from nutrient stress. Leaf reflectance data were obtained form a local vegetable crop, Brassica chinensis var parachinensis (Bailey), grown in nitrate-nitrogen (N)- and calcium (Ca)- deficient hydroponics nutrient solution. FOSpectr analysis showed significant differences in leaf reflectance within the first four days after subjecting plants to nutrient-deficient media. Recovery of the nutrient-stressed plants could also be detected after transferring them back to complete nutrient solution. In contrast to FOSpectr, plant response to nitrogen and calcium deficiency in terms of reduced growth and tissue elemental levels was slower and less pronounced. Thus, this study demonstrated the feasibility of using FOSpectr methodology as a non-destructive alternative to augment current methods of plant nutrient analysis.

  15. Increased nutritional quality of plants for long-duration spaceflight missions through choice of plant variety and manipulation of growth conditions

    NASA Astrophysics Data System (ADS)

    Cohu, Christopher M.; Lombardi, Elizabeth; Adams, William W.; Demmig-Adams, Barbara

    2014-02-01

    Low levels of radiation during spaceflight increase the incidence of eye damage and consumption of certain carotenoids (especially zeaxanthin), via a whole-food-based diet (rather than from supplements), is recommended to protect human vision against radiation damage. Availability of fresh leafy produce has, furthermore, been identified as desirable for morale during long spaceflight missions. We report that only trace amounts of zeaxanthin are retained post-harvest in leaves grown under conditions conducive to rapid plant growth. We show that growth of plants under cool temperatures and very high light can trigger a greater retention of zeaxanthin, while, however, simultaneously retarding plant growth. We here introduce a novel growth condition—low growth light supplemented with several short daily light pulses of higher intensity—that also triggers zeaxanthin retention, but without causing any growth retardation. Moreover, two plant varieties with different hardiness exhibited a different propensity for zeaxanthin retention. These findings demonstrate that growth light environment and plant variety can be exploited to simultaneously optimize nutritional quality (with respect to zeaxanthin and two other carotenoids important for human vision, lutein and β-carotene) as well as biomass production of leafy greens suitable as bioregenerative systems for long-duration manned spaceflight missions.

  16. Effect of Putrescine, 4-PU-30, and Abscisic Acid on Maize Plants Grown under Normal, Drought, and Rewatering Conditions.

    PubMed

    Todorov; Alexieva; Karanov

    1998-12-01

    The experiments were carried out with maize (Zea mays L.) seedlings, hybrid Kneja 530, grown hydroponically in a growth chamber. Twelve-day-old plants were foliar treated with putrescine, N1-(2-chloro-4-pyridyl)-N2-phenylurea (4-PU-30), and abscisic acid (ABA) at concentrations of 10(-5) m. Twenty-four hours later the plants were subjected to a water deficit program, induced by 15% polyethylene glycol (PEG; molecular weight, 6,000). Three days after drought stress half of the plants were transferred to nutrient solution for the next 3 days. The effects of the water shortage, rewatering, and plant growth regulator (PGR) treatment on the fresh and dry weights, leaf pigment content, proline level, relative water content (RWC), transpiration rate, activities of catalase and guaiacol peroxidase, hydrogen peroxide content, and level of the products of lipid peroxidation were studied. It was established that the application of PGRs alleviated to some extent the plant damage provoked by PEG stress. At the end of the water shortage program the plants treated with these PGRs possessed higher fresh weight than drought-subjected control seedlings. It was found also that putrescine increased the dry weight of plants. Under drought, the RWC and transpiration rate of seedlings declined, but PGR treatment reduced these effects. The accumulation of free proline, malondialdehyde, and hydrogen peroxide was prevented in PGR-treated plants compared with the water stress control. The results provided further information about the influence of putrescine, 4-PU-30, and ABA on maize plants grown under normal, drought, and rewatering conditions. Key Words. Maize-Putrescine-4-PU-30-ABA-Drought

  17. Protective effects of Glomus iranicum var. tenuihypharum on soil and Viburnum tinus plants irrigated with treated wastewater under field conditions.

    PubMed

    Gómez-Bellot, María José; Ortuño, María Fernanda; Nortes, Pedro Antonio; Vicente-Sánchez, Javier; Martín, Félix Fernández; Bañón, Sebastián; Sánchez-Blanco, María Jesús

    2015-07-01

    Currently, irrigation using recycled water is increasing, especially in semiarid environments, but a potential problem of using reclaimed wastewater is its elevated salt levels. The application of arbuscular mycorrhizal fungi (AMF) could be a suitable option to mitigate the negative effects produced by the salinity. In this work, the combined effect of Glomus iranicum var. tenuihypharum and two types of water: Control, C, with EC <0.9 dS m(-1) and reclaimed water (wastewater previously treated in a sewage treatment plant) with EC 4 dS m(-1) during a first saline period (11 weeks) and with EC 6 dS m(-1) during a second saline period (25 weeks), was evaluated for laurustinus (Viburnum tinus) plants under field conditions. This plant is a popular shrub very used for gardening. Chemical properties of soil as well as physiological behavior, leaf nutrition, and esthetic value of plants were evaluated. Due to the high salinity from wastewater at 6 dS m(-1), laurustinus plants decreased their stem water potential values and, to a lesser extent, the stomatal conductance. Also, the visual quality of the plants was diminished. The inoculated AMF satisfactorily colonized the laurustinus roots and enhanced the structure of the soil by increasing the glomalin and carbon contents. Furthermore, G. iranicum var. tenuihypharum inoculation decreased Na and Cl content, stimulated flowering and improved the stem water potential of the plants irrigated with both types of reclaimed water. The AMF also had a positive effect as a consequence of stimulation of plant physiological parameters, such as the stem water potential and stomatal conductance. Effective AMF associations that avoid excessive salinity could provide wastewater reuse options, especially when the plants grow in soils. PMID:25492808

  18. Protective effects of Glomus iranicum var. tenuihypharum on soil and Viburnum tinus plants irrigated with treated wastewater under field conditions.

    PubMed

    Gómez-Bellot, María José; Ortuño, María Fernanda; Nortes, Pedro Antonio; Vicente-Sánchez, Javier; Martín, Félix Fernández; Bañón, Sebastián; Sánchez-Blanco, María Jesús

    2015-07-01

    Currently, irrigation using recycled water is increasing, especially in semiarid environments, but a potential problem of using reclaimed wastewater is its elevated salt levels. The application of arbuscular mycorrhizal fungi (AMF) could be a suitable option to mitigate the negative effects produced by the salinity. In this work, the combined effect of Glomus iranicum var. tenuihypharum and two types of water: Control, C, with EC <0.9 dS m(-1) and reclaimed water (wastewater previously treated in a sewage treatment plant) with EC 4 dS m(-1) during a first saline period (11 weeks) and with EC 6 dS m(-1) during a second saline period (25 weeks), was evaluated for laurustinus (Viburnum tinus) plants under field conditions. This plant is a popular shrub very used for gardening. Chemical properties of soil as well as physiological behavior, leaf nutrition, and esthetic value of plants were evaluated. Due to the high salinity from wastewater at 6 dS m(-1), laurustinus plants decreased their stem water potential values and, to a lesser extent, the stomatal conductance. Also, the visual quality of the plants was diminished. The inoculated AMF satisfactorily colonized the laurustinus roots and enhanced the structure of the soil by increasing the glomalin and carbon contents. Furthermore, G. iranicum var. tenuihypharum inoculation decreased Na and Cl content, stimulated flowering and improved the stem water potential of the plants irrigated with both types of reclaimed water. The AMF also had a positive effect as a consequence of stimulation of plant physiological parameters, such as the stem water potential and stomatal conductance. Effective AMF associations that avoid excessive salinity could provide wastewater reuse options, especially when the plants grow in soils.

  19. Effect of Habitat Conditions and Plant Traits on Leaf Damage in the Carduoideae Subfamily

    PubMed Central

    Münzbergová, Zuzana; Skuhrovec, Jiří

    2013-01-01

    Plant traits are the key factors that determine herbivore foraging selection. The traits serving as defense traits against herbivores represent a wide range of traits, such as chemical, physiological, morphological and life-history traits. While many studies considered plant defense traits at the within-species scale, much less is known from comparisons of a wide range of closely related species. The aim of this study was to identify factors responsible for the intensity of leaf damage in the Carduoideae subfamily of Asteraceae, which hosts many invasive species and thus is potential candidate plant species that could be controlled by biological control. Specifically, we wanted to see the relative importance of habitat characteristics, plant size and plants traits in determining the degree of folivory. The study identified several defense traits able to explain differences in herbivory between species after accounting for differences in the habitats in which the species occur and the plant size. Specifically, the most important traits were traits related to the quality of the leaf tissue expressed as the content of phosphorus, water and specific leaf area, which suggests that the leaf quality had a more important effect on the degree of herbivory than the presence of specific defense mechanisms such as spines and hair. Leaf quality is thus a candidate factor that drives herbivore choice when selecting which plant to feed on and should be considered when assessing the danger that a herbivore will switch hosts when introduced to a new range. PMID:23717643

  20. How People Actually Use Thermostats

    SciTech Connect

    Meier, Alan; Aragon, Cecilia; Hurwitz, Becky; Mujumdar, Dhawal; Peffer, Therese; Perry, Daniel; Pritoni, Marco

    2010-08-15

    Residential thermostats have been a key element in controlling heating and cooling systems for over sixty years. However, today's modern programmable thermostats (PTs) are complicated and difficult for users to understand, leading to errors in operation and wasted energy. Four separate tests of usability were conducted in preparation for a larger study. These tests included personal interviews, an on-line survey, photographing actual thermostat settings, and measurements of ability to accomplish four tasks related to effective use of a PT. The interviews revealed that many occupants used the PT as an on-off switch and most demonstrated little knowledge of how to operate it. The on-line survey found that 89% of the respondents rarely or never used the PT to set a weekday or weekend program. The photographic survey (in low income homes) found that only 30% of the PTs were actually programmed. In the usability test, we found that we could quantify the difference in usability of two PTs as measured in time to accomplish tasks. Users accomplished the tasks in consistently shorter times with the touchscreen unit than with buttons. None of these studies are representative of the entire population of users but, together, they illustrate the importance of improving user interfaces in PTs.

  1. Strigolactone Regulates Anthocyanin Accumulation, Acid Phosphatases Production and Plant Growth under Low Phosphate Condition in Arabidopsis

    PubMed Central

    Ito, Shinsaku; Nozoye, Tomoko; Sasaki, Eriko; Imai, Misaki; Shiwa, Yuh; Shibata-Hatta, Mari; Ishige, Taichiro; Fukui, Kosuke; Ito, Ken; Nakanishi, Hiromi; Nishizawa, Naoko K.; Yajima, Shunsuke; Asami, Tadao

    2015-01-01

    Phosphate is an essential macronutrient in plant growth and development; however, the concentration of inorganic phosphate (Pi) in soil is often suboptimal for crop performance. Accordingly, plants have developed physiological strategies to adapt to low Pi availability. Here, we report that typical Pi starvation responses in Arabidopsis are partially dependent on the strigolactone (SL) signaling pathway. SL treatment induced root hair elongation, anthocyanin accumulation, activation of acid phosphatase, and reduced plant weight, which are characteristic responses to phosphate starvation. Furthermore, the expression profile of SL-response genes correlated with the expression of genes induced by Pi starvation. These results suggest a potential overlap between SL signaling and Pi starvation signaling pathways in plants. PMID:25793732

  2. ``From seed-to-seed'' experiment with wheat plants under space-flight conditions

    NASA Astrophysics Data System (ADS)

    Mashinsky, A.; Ivanova, I.; Derendyaeva, T.; Nechitailo, G.; Salisbury, F.

    1994-11-01

    An important goal with plant experiments in microgravity is to achieve a complete life cycle, the ``seed-to-seed experiment''. Some Soviet attempts to reach this goal are described, notably an experiment with the tiny mustard, Arabidopsis thaliana, in the Phyton 3 device on Salyut 7. Normal seeds were produced although yields were reduced and development was delayed. Several other experiments have shown abnormalities in plants grown in space. In recent work, plants of wheat (Triticum aestivum) were studied on the ground and then in a preliminary experiment in space. Biometric indices of vegetative space plants were 2 to 2.5 times lower than those of controls, levels of chlorophyll a and b were reduced (no change in the ratio of the two pigments), carotenoids were reduced, there was a serious imbalance in major minerals, and membrane lipids were reduced (no obvious change in lipid patterns). Following the preliminary studies, an attempt was made with the Svetoblock-M growth unit to grow a super-dwarf wheat cultivar through a life cycle. The experiment lasted 167 d on Mir. Growth halted from about day 40 to day 100, when new shoots appeared. Three heads had appeared in the boot (surrounded by leaves) when plants were returned to earth. One head was sterile, but 28 seeds matured on earth, and most of these have since produced normal plants and seeds. In principle, a seed-to-seed experiment with wheat should be successful in microgravity.

  3. Accumulation of N-Acetylglucosamine Oligomers in the Plant Cell Wall Affects Plant Architecture in a Dose-Dependent and Conditional Manner1[W][OPEN

    PubMed Central

    Vanholme, Bartel; Vanholme, Ruben; Turumtay, Halbay; Goeminne, Geert; Cesarino, Igor; Goubet, Florence; Morreel, Kris; Rencoret, Jorge; Bulone, Vincent; Hooijmaijers, Cortwa; De Rycke, Riet; Gheysen, Godelieve; Ralph, John; De Block, Marc; Meulewaeter, Frank; Boerjan, Wout

    2014-01-01

    To study the effect of short N-acetylglucosamine (GlcNAc) oligosaccharides on the physiology of plants, N-ACETYLGLUCOSAMINYLTRANSFERASE (NodC) of Azorhizobium caulinodans was expressed in Arabidopsis (Arabidopsis thaliana). The corresponding enzyme catalyzes the polymerization of GlcNAc and, accordingly, β-1,4-GlcNAc oligomers accumulated in the plant. A phenotype characterized by difficulties in developing an inflorescence stem was visible when plants were grown for several weeks under short-day conditions before transfer to long-day conditions. In addition, a positive correlation between the oligomer concentration and the penetrance of the phenotype was demonstrated. Although NodC overexpression lines produced less cell wall compared with wild-type plants under nonpermissive conditions, no indications were found for changes in the amount of the major cell wall polymers. The effect on the cell wall was reflected at the transcriptome level. In addition to genes encoding cell wall-modifying enzymes, a whole set of genes encoding membrane-coupled receptor-like kinases were differentially expressed upon GlcNAc accumulation, many of which encoded proteins with an extracellular Domain of Unknown Function26. Although stress-related genes were also differentially expressed, the observed response differed from that of a classical chitin response. This is in line with the fact that the produced chitin oligomers were too small to activate the chitin receptor-mediated signal cascade. Based on our observations, we propose a model in which the oligosaccharides modify the architecture of the cell wall by acting as competitors in carbohydrate-carbohydrate or carbohydrate-protein interactions, thereby affecting noncovalent interactions in the cell wall or at the interface between the cell wall and the plasma membrane. PMID:24664205

  4. Accumulation of N-acetylglucosamine oligomers in the plant cell wall affects plant architecture in a dose-dependent and conditional manner.

    PubMed

    Vanholme, Bartel; Vanholme, Ruben; Turumtay, Halbay; Goeminne, Geert; Cesarino, Igor; Goubet, Florence; Morreel, Kris; Rencoret, Jorge; Bulone, Vincent; Hooijmaijers, Cortwa; De Rycke, Riet; Gheysen, Godelieve; Ralph, John; De Block, Marc; Meulewaeter, Frank; Boerjan, Wout

    2014-05-01

    To study the effect of short N-acetylglucosamine (GlcNAc) oligosaccharides on the physiology of plants, N-ACETYLGLUCOSAMINYLTRANSFERASE (NodC) of Azorhizobium caulinodans was expressed in Arabidopsis (Arabidopsis thaliana). The corresponding enzyme catalyzes the polymerization of GlcNAc and, accordingly, β-1,4-GlcNAc oligomers accumulated in the plant. A phenotype characterized by difficulties in developing an inflorescence stem was visible when plants were grown for several weeks under short-day conditions before transfer to long-day conditions. In addition, a positive correlation between the oligomer concentration and the penetrance of the phenotype was demonstrated. Although NodC overexpression lines produced less cell wall compared with wild-type plants under nonpermissive conditions, no indications were found for changes in the amount of the major cell wall polymers. The effect on the cell wall was reflected at the transcriptome level. In addition to genes encoding cell wall-modifying enzymes, a whole set of genes encoding membrane-coupled receptor-like kinases were differentially expressed upon GlcNAc accumulation, many of which encoded proteins with an extracellular Domain of Unknown Function26. Although stress-related genes were also differentially expressed, the observed response differed from that of a classical chitin response. This is in line with the fact that the produced chitin oligomers were too small to activate the chitin receptor-mediated signal cascade. Based on our observations, we propose a model in which the oligosaccharides modify the architecture of the cell wall by acting as competitors in carbohydrate-carbohydrate or carbohydrate-protein interactions, thereby affecting noncovalent interactions in the cell wall or at the interface between the cell wall and the plasma membrane.

  5. Assessment of the microbiological conditions of tails, tongues, and head meats at two beef-packing plants.

    PubMed

    Gill, C O; McGinnis, J C; Jones, T

    1999-06-01

    Newly skinned tails of beef carcasses at two packing plants were similarly contaminated with total aerobes and with coliforms that were largely Escherichia coli at log mean numbers about 3.5/cm2 and 4.5/100 cm2, respectively. The log mean numbers of aerobes and coliforms on the skinned tails after washing at plant A were, respectively, 1 and 2 log units less than the numbers on the newly skinned tails. At plant B, the log mean numbers of aerobes on skinned and on washed tails were similar while the log mean numbers of E. coli on washed tails were only about 1 log unit less than the numbers on skinned tails. Cooling of tails on racks in a chiller at plant B reduced the log mean numbers of E. coli by about 1 log unit but did not reduce the numbers of total aerobes. Tongues in the heads of carcasses at both plants were similarly contaminated with total aerobes and with coliforms that were largely E. coli at log mean numbers of about 4.5/cm2 and 4.5/100 cm2, respectively. The log mean numbers of aerobes on and the log total number of E. coli recovered from washed tongues were, respectively, about 2 and 4 log units less than for unwashed tongues at plant A and about 1 and 3 log units less than for unwashed tongues at plant B. The log mean numbers of aerobes and E. coli on washed cheeks and lips were both about 2 log units less than the numbers on unwashed tongues at both plants. With appropriate collection and washing procedures, the microbiological conditions of beef tails, tongues, and head meats can apparently be comparable to those of primal cuts and manufacturing beef at the times that the products are packed. PMID:10382660

  6. Beneficial native bacteria improve survival and mycorrhization of desert truffle mycorrhizal plants in nursery conditions.

    PubMed

    Navarro-Ródenas, Alfonso; Berná, Luis Miguel; Lozano-Carrillo, Cecilia; Andrino, Alberto; Morte, Asunción

    2016-10-01

    Sixty-four native bacterial colonies were isolated from mycorrhizal roots of Helianthemum almeriense colonized by Terfezia claveryi, mycorrhizosphere soil, and peridium of T. claveryi to evaluate their effect on mycorrhizal plant production. Based on the phylogenetic analysis of the 16S rDNA partial sequence, 45 different strains from 17 genera were gathered. The largest genera were Pseudomonas (40.8 % of the isolated strains), Bacillus (12.2 % of isolated strains), and Varivorax (8.2 % of isolated strains). All the bacteria were characterized phenotypically and by their plant growth-promoting rhizobacteria (PGPR) traits (auxin and siderophore production, phosphate solubilization, and ACC deaminase activity). Only bacterial combinations with several PGPR traits or Pseudomonas sp. strain 5, which presents three different PGPR traits, had a positive effect on plant survival and growth. Particularly relevant were the bacterial treatments involving auxin release, which significantly increased the root-shoot ratio and mycorrhizal colonization. Moreover, Pseudomonas mandelii strain 29 was able to considerably increase mycorrhizal colonization but not plant growth, and could be considered as mycorrhiza-helper bacteria. Therefore, the mycorrhizal roots, mycorrhizosphere soil, and peridium of desert truffles are environments enriched in bacteria which may be used to increase the survival and mycorrhization in the desert truffle plant production system at a semi-industrial scale.

  7. Beneficial native bacteria improve survival and mycorrhization of desert truffle mycorrhizal plants in nursery conditions.

    PubMed

    Navarro-Ródenas, Alfonso; Berná, Luis Miguel; Lozano-Carrillo, Cecilia; Andrino, Alberto; Morte, Asunción

    2016-10-01

    Sixty-four native bacterial colonies were isolated from mycorrhizal roots of Helianthemum almeriense colonized by Terfezia claveryi, mycorrhizosphere soil, and peridium of T. claveryi to evaluate their effect on mycorrhizal plant production. Based on the phylogenetic analysis of the 16S rDNA partial sequence, 45 different strains from 17 genera were gathered. The largest genera were Pseudomonas (40.8 % of the isolated strains), Bacillus (12.2 % of isolated strains), and Varivorax (8.2 % of isolated strains). All the bacteria were characterized phenotypically and by their plant growth-promoting rhizobacteria (PGPR) traits (auxin and siderophore production, phosphate solubilization, and ACC deaminase activity). Only bacterial combinations with several PGPR traits or Pseudomonas sp. strain 5, which presents three different PGPR traits, had a positive effect on plant survival and growth. Particularly relevant were the bacterial treatments involving auxin release, which significantly increased the root-shoot ratio and mycorrhizal colonization. Moreover, Pseudomonas mandelii strain 29 was able to considerably increase mycorrhizal colonization but not plant growth, and could be considered as mycorrhiza-helper bacteria. Therefore, the mycorrhizal roots, mycorrhizosphere soil, and peridium of desert truffles are environments enriched in bacteria which may be used to increase the survival and mycorrhization in the desert truffle plant production system at a semi-industrial scale. PMID:27262434

  8. The Utilization of Plant Facilities on the International Space Station—The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions

    PubMed Central

    Jost, Ann-Iren Kittang; Hoson, Takayuki; Iversen, Tor-Henning

    2015-01-01

    In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g) conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8–14 days) on single cells (plant protoplasts). Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station. PMID:27135317

  9. The Utilization of Plant Facilities on the International Space Station-The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions.

    PubMed

    Jost, Ann-Iren Kittang; Hoson, Takayuki; Iversen, Tor-Henning

    2015-01-20

    In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g) conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8-14 days) on single cells (plant protoplasts). Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station.

  10. The Utilization of Plant Facilities on the International Space Station-The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions.

    PubMed

    Jost, Ann-Iren Kittang; Hoson, Takayuki; Iversen, Tor-Henning

    2015-01-01

    In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g) conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8-14 days) on single cells (plant protoplasts). Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station. PMID:27135317

  11. Influence of deposition of fine plant debris in river floodplain shrubs on flood flow conditions - The Warta River case study

    NASA Astrophysics Data System (ADS)

    Mazur, Robert; Kałuża, Tomasz; Chmist, Joanna; Walczak, Natalia; Laks, Ireneusz; Strzeliński, Paweł

    2016-08-01

    This paper presents problems caused by organic material transported by flowing water. This material is usually referred to as plant debris or organic debris. Its composition depends on the characteristic of the watercourse. For lowland rivers, the share of the so-called small organic matter in plant debris is considerable. This includes both various parts of water plants and floodplain vegetation (leaves, stems, blades of grass, twigs, etc.). During floods, larger woody debris poses a significant risk to bridges or other water engineering structures. It may cause river jams and may lead to damming of the flowing water. This, in turn, affects flood safety and increases flood risk in river valleys, both directly and indirectly. The importance of fine plant debris for the phenomenon being studied comes down to the hydrodynamic aspect (plant elements carried by water end up on trees and shrubs, increase hydraulic flow resistance and contribute to the nature of flow through vegetated areas changed from micro-to macro-structural). The key part of the research problem under analysis was to determine qualitative and quantitative debris parameters and to establish the relationship between the type of debris and the type of land use of river valleys (crop fields, meadows and forested river sections). Another problem was to identify parameters of plant debris for various flow conditions (e.g. for low, medium and flood flows). The research also included an analysis of the materials deposited on the structure of shrubs under flood flow conditions during the 2010 flood on the Warta River.

  12. Propagule Pressure, Habitat Conditions and Clonal Integration Influence the Establishment and Growth of an Invasive Clonal Plant, Alternanthera philoxeroides

    PubMed Central

    You, Wen-Hua; Han, Cui-Min; Fang, Long-Xiang; Du, Dao-Lin

    2016-01-01

    Many notorious invasive plants are clonal, spreading mainly by vegetative propagules. Propagule pressure (the number of propagules) may affect the establishment, growth, and thus invasion success of these clonal plants, and such effects may also depend on habitat conditions. To understand how propagule pressure, habitat conditions and clonal integration affect the establishment and growth of the invasive clonal plants, an 8-week greenhouse with an invasive clonal plant, Alternanthera philoxeroides was conducted. High (five fragments) or low (one fragment) propagule pressure was established either in bare soil (open habitat) or dense native vegetation of Jussiaea repens (vegetative habitat), with the stolon connections either severed from or connected to the relatively older ramets. High propagule pressure greatly increased the establishment and growth of A. philoxeroides, especially when it grew in vegetative habitats. Surprisingly, high propagule pressure significantly reduced the growth of individual plants of A. philoxeroides in open habitats, whereas it did not affect the individual growth in vegetative habitats. A shift in the intraspecific interaction on A. philoxeroides from competition in open habitats to facilitation in vegetative habitats may be the main reason. Moreover, clonal integration significantly improved the growth of A. philoxeroides only in open habitats, especially with low propagule pressure, whereas it had no effects on the growth and competitive ability of A. philoxeroides in vegetative habitats, suggesting that clonal integration may be of most important for A. philoxeroides to explore new open space and spread. These findings suggest that propagule pressure may be crucial for the invasion success of A. philoxeroides, and such an effect also depends on habitat conditions. PMID:27200041

  13. Propagule Pressure, Habitat Conditions and Clonal Integration Influence the Establishment and Growth of an Invasive Clonal Plant, Alternanthera philoxeroides.

    PubMed

    You, Wen-Hua; Han, Cui-Min; Fang, Long-Xiang; Du, Dao-Lin

    2016-01-01

    Many notorious invasive plants are clonal, spreading mainly by vegetative propagules. Propagule pressure (the number of propagules) may affect the establishment, growth, and thus invasion success of these clonal plants, and such effects may also depend on habitat conditions. To understand how propagule pressure, habitat conditions and clonal integration affect the establishment and growth of the invasive clonal plants, an 8-week greenhouse with an invasive clonal plant, Alternanthera philoxeroides was conducted. High (five fragments) or low (one fragment) propagule pressure was established either in bare soil (open habitat) or dense native vegetation of Jussiaea repens (vegetative habitat), with the stolon connections either severed from or connected to the relatively older ramets. High propagule pressure greatly increased the establishment and growth of A. philoxeroides, especially when it grew in vegetative habitats. Surprisingly, high propagule pressure significantly reduced the growth of individual plants of A. philoxeroides in open habitats, whereas it did not affect the individual growth in vegetative habitats. A shift in the intraspecific interaction on A. philoxeroides from competition in open habitats to facilitation in vegetative habitats may be the main reason. Moreover, clonal integration significantly improved the growth of A. philoxeroides only in open habitats, especially with low propagule pressure, whereas it had no effects on the growth and competitive ability of A. philoxeroides in vegetative habitats, suggesting that clonal integration may be of most important for A. philoxeroides to explore new open space and spread. These findings suggest that propagule pressure may be crucial for the invasion success of A. philoxeroides, and such an effect also depends on habitat conditions. PMID:27200041

  14. Macroscopic mass and energy balance of a pilot plant anaerobic bioreactor operated under thermophilic conditions.

    PubMed

    Espinosa-Solares, Teodoro; Bombardiere, John; Chatfield, Mark; Domaschko, Max; Easter, Michael; Stafford, David A; Castillo-Angeles, Saul; Castellanos-Hernandez, Nehemias

    2006-01-01

    Intensive poultry production generates over 100,000 t of litter annually in West Virginia and 9 x 10(6) t nationwide. Current available technological alternatives based on thermophilic anaerobic digestion for residuals treatment are diverse. A modification of the typical continuous stirred tank reactor is a promising process being relatively stable and owing to its capability to manage considerable amounts of residuals at low operational cost. A 40-m3 pilot plant digester was used for performance evaluation considering energy input and methane production. Results suggest some changes to the pilot plant configuration are necessary to reduce power consumption although maximizing biodigester performance.

  15. Metabolic engineering with Dof1 transcription factor in plants: Improved nitrogen assimilation and growth under low-nitrogen conditions

    PubMed Central

    Yanagisawa, Shuichi; Akiyama, Ai; Kisaka, Hiroaki; Uchimiya, Hirofumi; Miwa, Tetuya

    2004-01-01

    Utilization of transcription factors might be a powerful approach to modification of metabolism for a generation of crops having superior characteristics because a single transcription factor frequently regulates coordinated expression of a set of key genes for respective pathways. Here, we apply the plant-specific Dof1 transcription factor to improve nitrogen assimilation, the essential metabolism including the primary assimilation of ammonia to carbon skeletons to biosynthesize amino acids and other organic compounds involving nitrogen in plants. Expressing Dof1 induced the up-regulation of genes encoding enzymes for carbon skeleton production, a marked increase of amino acid contents, and a reduction of the glucose level in transgenic Arabidopsis. The results suggest cooperative modification of carbon and nitrogen metabolisms on the basis of their intimate link. Furthermore, elementary analysis revealed that the nitrogen content increased in the Dof1 transgenic plants (≈30%), indicating promotion of net nitrogen assimilation. Most significantly, the Dof1 transgenic plants exhibit improved growth under low-nitrogen conditions, an agronomically important trait. These results highlight the great utility of transcription factors in engineering metabolism in plants. PMID:15136740

  16. Acclimatization of communities of ammonia oxidizing bacteria to seasonal changes in optimal conditions in a coke wastewater treatment plant.

    PubMed

    Kim, Young Mo

    2013-11-01

    The goal of this study was to investigate the correlation between optimal conditions of ammonia oxidation rates (AORs) and communities of ammonia oxidizing bacteria (AOB) adapting to seasonal changes in a full-scale wastewater treatment plant (WWTP). The optimal temperature and pH of specific AORs reflected seasonal variation patterns, showing the lowest values during the cold season, while the highest values in the warm season. Throughout the study period, Nitrosomonas europaea/eutropha and Nitrosomonas nitrosa remained the dominant AOB, indicating resistance to the influences of a changing environment. These results show that the optimal conditions for AOR can be adjusted to accommodate changing environmental conditions, relying on the acclimatization of a stable AOB community to given conditions, without any visible shift in the AOB community.

  17. ARE INVASIVE RIPARIAN PLANTS ASSOCIATED WITH REDUCED BIOTIC CONDITION OF FAUNA IN WESTERN US STREAMS?

    EPA Science Inventory

    Yes. Records on the presence or absence of 12 invasive riparian plant taxa and observations on macroinvertebrate and vertebrate communities within streams were collected at over 1000 stream reaches. The sampled reaches were selected on a probability basis to represent the populat...

  18. SNP markers linked to QTL conditioning plant height, lodging, and maturity in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max L. Merr.) is a major crop and a leading source of protein meal and edible oil worldwide. Plant height (PHT), lodging (LDG), and days to maturity (MAT) are three important agronomic traits that influence the seed yield of soybean. The objective of this study was to map quantitati...

  19. Use of perlite in cadmium plant studies: an approach to polluted soil conditions.

    PubMed

    Vázquez, Saúl; Carpena-Ruiz, Ramón

    2005-12-01

    Two different types of hydroponic cultures, "water culture" and "perlite system", were compared using white lupin plants (Lupinus albus L., cv. Marta) under different Cd treatments: 0, 0.2, 0.6, 2, 4, 6, 13, 20, 40 and 60 microM (water culture) and 0.2, 2, 20, 60 and 150 microM (moistened perlite). Fresh weight, shoot and root length, and total Cd concentration in the plants were measured. Moreover, a batch experiment was carried out to study the ability of perlite to adsorb and desorb Cd from nutrient solution. Lupin plants under Cd treatments in "water culture" showed a higher growth inhibition than those grown on perlite. A high positive correlation between Cd concentration in the plant and Cd supply was obtained regardless of the substrate used. Moreover, a high positive correlation between Cd doses with the "perlite system" and their equivalent Cd doses estimated for the "water culture" system was observed. Thus, the "water culture-equivalent" Cd doses were 14 times lower than the Cd doses in the perlite system. On the other hand, desorbed Cd concentrations were calculated giving values 12 times lower than the tested Cd doses. PMID:16307096

  20. Use of a Simple, Colorimetric Assay to Demonstrate Conditions for Induction of Nitrate Reductase in Plants.

    ERIC Educational Resources Information Center

    Harley, Suzanne M.

    1993-01-01

    Nitrate assimilation by plants provides an excellent system for demonstrating control of gene expression in a eukaryotic organism. Describes an assay method that allows students to complete experiments designed around the measurement of nitrate reductase within a three-hour laboratory experiment. (PR)

  1. The condition of browse plants at the Theodore Roosevelt Memorial Ranch (TRMR)

    USGS Publications Warehouse

    Keigley, R.B.; Olson, Gary R.

    2001-01-01

    As background for a more comprehensive study, we collected data in September and October 1999 from which to assess the impact of ungulates on browse plants. There were three general objectives: 1) determine the current level of browsing intensity, 2) reconstruct histories of browsing, and 3) determine the effect of browsing on rate of stem growth.

  2. Life history of Paracoccus marginatus (Hemiptera:Pseudococcidae)on four host plant species under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development, survival and reproduction of the papaya mealybug (Paracoccus marginatus Williams and Granara de Willink) on three ornamental plants (Hibiscus rosa-sinensis L., Acalypha sp. and Plumeria sp.) and one weed species (Parthenium hysterophorus L.) were investigated. Papaya mealybug was able t...

  3. The contribution of woody plant materials on the several conditions in a space environment

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Baba, Keiichi; Suzuki, Toshisada; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Abe, Yusuke; Katayama, Takeshi

    Woody plant materials have several utilization elements in our habitation environment on earth. The studies of woody plants under a space-environment in the vegetable kingdom have a high contribution to the study of various and exotic environmental responses, too. Woody plants can produce an excess oxygen, woody materials for the living cabin, and provide a biomass by cultivating crops and other species of creatures. Tree material would become to be a tool in closed bio-ecosystems such as an environment in a space. We named the trees used as material for the experiment related to space environments “CosmoBon”, small tree bonsai. Japanese cherry tree, “Sakura”, is famous and lovely tree in Japan. One species of “Sakura”, “Mamezakura, Prunus incisa”, is not only lovely tree species, but also suitable tree for the model tree of our purpose. The species of Prunus incisa is originally grown in volcano environment. That species of Sakura is originally grown on Mt. Fuji aria, oligotrophic place. We will try to build the best utilization usage of woody plant under the space environment by “Mamezakura” as a model tree. Here, we will show the importance of uniformity of materials when we will use the tree materials in a space environment. We will also discuss that tree has a high possibility of utilization under the space environments by using our several results related to this research.

  4. Use of perlite in cadmium plant studies: an approach to polluted soil conditions.

    PubMed

    Vázquez, Saúl; Carpena-Ruiz, Ramón

    2005-12-01

    Two different types of hydroponic cultures, "water culture" and "perlite system", were compared using white lupin plants (Lupinus albus L., cv. Marta) under different Cd treatments: 0, 0.2, 0.6, 2, 4, 6, 13, 20, 40 and 60 microM (water culture) and 0.2, 2, 20, 60 and 150 microM (moistened perlite). Fresh weight, shoot and root length, and total Cd concentration in the plants were measured. Moreover, a batch experiment was carried out to study the ability of perlite to adsorb and desorb Cd from nutrient solution. Lupin plants under Cd treatments in "water culture" showed a higher growth inhibition than those grown on perlite. A high positive correlation between Cd concentration in the plant and Cd supply was obtained regardless of the substrate used. Moreover, a high positive correlation between Cd doses with the "perlite system" and their equivalent Cd doses estimated for the "water culture" system was observed. Thus, the "water culture-equivalent" Cd doses were 14 times lower than the Cd doses in the perlite system. On the other hand, desorbed Cd concentrations were calculated giving values 12 times lower than the tested Cd doses.

  5. 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

  6. 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. PMID:27379240

  7. Adjustment of carbon fluxes to light conditions regulates the daily turnover of starch in plants: a computational model.

    PubMed

    Pokhilko, Alexandra; Flis, Anna; Sulpice, Ronan; Stitt, Mark; Ebenhöh, Oliver

    2014-03-01

    In the light, photosynthesis provides carbon for metabolism and growth. In the dark, plant growth depends on carbon reserves that were accumulated during previous light periods. Many plants accumulate part of their newly-fixed carbon as starch in their leaves in the day and remobilise it to support metabolism and growth at night. The daily rhythms of starch accumulation and degradation are dynamically adjusted to the changing light conditions such that starch is almost but not totally exhausted at dawn. This requires the allocation of a larger proportion of the newly fixed carbon to starch under low carbon conditions, and the use of information about the carbon status at the end of the light period and the length of the night to pace the rate of starch degradation. This regulation occurs in a circadian clock-dependent manner, through unknown mechanisms. We use mathematical modelling to explore possible diurnal mechanisms regulating the starch level. Our model combines the main reactions of carbon fixation, starch and sucrose synthesis, starch degradation and consumption of carbon by sink tissues. To describe the dynamic adjustment of starch to daily conditions, we introduce diurnal regulators of carbon fluxes, which modulate the activities of the key steps of starch metabolism. The sensing of the diurnal conditions is mediated in our model by the timer α and the "dark sensor"β, which integrate daily information about the light conditions and time of the day through the circadian clock. Our data identify the β subunit of SnRK1 kinase as a good candidate for the role of the dark-accumulated component β of our model. The developed novel approach for understanding starch kinetics through diurnal metabolic and circadian sensors allowed us to explain starch time-courses in plants and predict the kinetics of the proposed diurnal regulators under various genetic and environmental perturbations.

  8. TsPAP1 encodes a novel plant prolyl aminopeptidase whose expression is induced in response to suboptimal growth conditions

    SciTech Connect

    Szawlowska, Urszula; Grabowska, Agnieszka; Zdunek-Zastocka, Edyta; Bielawski, Wieslaw

    2012-03-02

    Highlights: Black-Right-Pointing-Pointer A cDNA encoding a novel plant prolyl aminopeptidase, TsPAP1, was obtained from triticale. Black-Right-Pointing-Pointer The cloned TsPAP1 cDNA is 1387 bp long and encodes a protein of 390 amino acids. Black-Right-Pointing-Pointer The deduced TsPAP1 protein revealed characteristics of the monomeric bacterial PAPs. Black-Right-Pointing-Pointer The TsPAP1 mRNA level increased under drought, salinity and in the presence of metal ions. -- Abstract: A triticale cDNA encoding a prolyl aminopeptidase (PAP) was obtained by RT-PCR and has been designated as TsPAP1. The cloned cDNA is 1387 bp long and encodes a protein of 390 amino acids with a calculated molecular mass of 43.9 kDa. The deduced TsPAP1 protein exhibits a considerable sequence identity with the biochemically characterized bacterial and fungal PAP proteins of small molecular masses ({approx}35 kDa). Moreover, the presence of conserved regions that are characteristic for bacterial monomeric PAP enzymes (the GGSWG motif, the localization of the catalytic triad residues and the segment involved in substrate binding) has also been noted. Primary structure analysis and phylogenetic analysis revealed that TsPAP1 encodes a novel plant PAP protein that is distinct from the multimeric proteins that have thus far been characterized in plants and whose counterparts have been recognized only in bacteria and fungi. A significant increase in the TsPAP1 transcript level in the shoots of triticale plants was observed under drought and saline conditions as well as in the presence of cadmium and aluminium ions in the nutrient medium. This paper is the first report describing changes in the transcript levels of any plant PAP in response to suboptimal growth conditions.

  9. Promoting scopolamine biosynthesis in transgenic Atropa belladonna plants with pmt and h6h overexpression under field conditions.

    PubMed

    Xia, Ke; Liu, Xiaoqiang; Zhang, Qiaozhuo; Qiang, Wei; Guo, Jianjun; Lan, Xiaozhong; Chen, Min; Liao, Zhihua

    2016-09-01

    Atropa belladonna is one of the most important plant sources for producing pharmaceutical tropane alkaloids (TAs). T1 progeny of transgenic A. belladonna, in which putrescine N-methyltransferase (EC. 2.1.1.53) from Nicotiana tabacum (NtPMT) and hyoscyamine 6β-hydroxylase (EC. 1.14.11.14) from Hyoscyamus niger (HnH6H) were overexpressed, were established to investigate TA biosynthesis and distribution in ripe fruits, leaves, stems, primary roots and secondary roots under field conditions. Both NtPMT and HnH6H were detected at the transcriptional level in transgenic plants, whereas they were not detected in wild-type plants. The transgenes did not influence the root-specific expression patterns of endogenous TA biosynthetic genes in A. belladonna. All four endogenous TA biosynthetic genes (AbPMT, AbTRI, AbCYP80F1 and AbH6H) had the highest/exclusive expression levels in secondary roots, suggesting that TAs were mainly synthesized in secondary roots. T1 progeny of transgenic A. belladonna showed an impressive scopolamine-rich chemotype that greatly improved the pharmaceutical value of A. belladonna. The higher efficiency of hyoscyamine conversion was found in aerial than in underground parts. In aerial parts of transgenic plants, hyoscyamine was totally converted to downstream alkaloids, especially scopolamine. Hyoscyamine, anisodamine and scopolamine were detected in underground parts, but scopolamine and anisodamine were more abundant than hyoscyamine. The exclusively higher levels of anisodamine in roots suggested that it might be difficult for its translocation from root to aerial organs. T1 progeny of transgenic A. belladonna, which produces scopolamine at very high levels (2.94-5.13 mg g(-1)) in field conditions, can provide more valuable plant materials for scopolamine production. PMID:27135818

  10. The actual goals of geoethics

    NASA Astrophysics Data System (ADS)

    Nemec, Vaclav

    2014-05-01

    The most actual goals of geoethics have been formulated as results of the International Conference on Geoethics (October 2013) held at the geoethics birth-place Pribram (Czech Republic): In the sphere of education and public enlightenment an appropriate needed minimum know how of Earth sciences should be intensively promoted together with cultivating ethical way of thinking and acting for the sustainable well-being of the society. The actual activities of the Intergovernmental Panel of Climate Changes are not sustainable with the existing knowledge of the Earth sciences (as presented in the results of the 33rd and 34th International Geological Congresses). This knowledge should be incorporated into any further work of the IPCC. In the sphere of legislation in a large international co-operation following steps are needed: - to re-formulate the term of a "false alarm" and its legal consequences, - to demand very consequently the needed evaluation of existing risks, - to solve problems of rights of individuals and minorities in cases of the optimum use of mineral resources and of the optimum protection of the local population against emergency dangers and disasters; common good (well-being) must be considered as the priority when solving ethical dilemmas. The precaution principle should be applied in any decision making process. Earth scientists presenting their expert opinions are not exempted from civil, administrative or even criminal liabilities. Details must be established by national law and jurisprudence. The well known case of the L'Aquila earthquake (2009) should serve as a serious warning because of the proven misuse of geoethics for protecting top Italian seismologists responsible and sentenced for their inadequate superficial behaviour causing lot of human victims. Another recent scandal with the Himalayan fossil fraud will be also documented. A support is needed for any effort to analyze and to disclose the problems of the deformation of the contemporary

  11. Dose-projection considerations for emergency conditions at nuclear power plants

    SciTech Connect

    Stoetzel, G.A.; Ramsdell, J.V.; Poeton, R.W.; Powell, D.C.; Desrosiers, A.E.

    1983-05-01

    The purpose of this report is to review the problems and issues associated with making environmental radiation-dose projections during emergencies at nuclear power plants. The review is divided into three areas: source-term development, characterization of atmospheric dispersion and selection of appropriate dispersion models, and development of dosimetry calculations for determining thyroid dose and whole-body dose for ground-level and elevated releases. A discussion of uncertainties associated with these areas is also provided.

  12. Species and tissue type regulate long-term decomposition of brackish marsh plants grown under elevated CO2 conditions

    NASA Astrophysics Data System (ADS)

    Jones, Joshua A.; Cherry, Julia A.; McKee, Karen L.

    2016-02-01

    Organic matter accumulation, the net effect of plant production and decomposition, contributes to vertical soil accretion in coastal wetlands, thereby playing a key role in whether they keep pace with sea-level rise. Any factor that affects decomposition may affect wetland accretion, including atmospheric CO2 concentrations. Higher CO2 can influence decomposition rates by altering plant tissue chemistry or by causing shifts in plant species composition or biomass partitioning. A combined greenhouse-field experiment examined how elevated CO2 affected plant tissue chemistry and subsequent decomposition of above- and belowground tissues of two common brackish marsh species, Schoenoplectus americanus (C3) and Spartina patens (C4). Both species were grown in monoculture and in mixture under ambient (350-385 μL L-1) or elevated (ambient + 300 μL L-1) atmospheric CO2 conditions, with all other growth conditions held constant, for one growing season. Above- and belowground tissues produced under these treatments were decomposed under ambient field conditions in a brackish marsh in the Mississippi River Delta, USA. Elevated CO2 significantly reduced nitrogen content of S. americanus, but not sufficiently to affect subsequent decomposition. Instead, long-term decomposition (percent mass remaining after 280 d) was controlled by species composition and tissue type. Shoots of S. patens had more mass remaining (41 ± 2%) than those of S. americanus (12 ± 2%). Belowground material decomposed more slowly than that placed aboveground (62 ± 1% vs. 23 ± 3% mass remaining), but rates belowground did not differ between species. Increases in atmospheric CO2 concentration will likely have a greater effect on overall decomposition in this brackish marsh community through shifts in species dominance or biomass allocation than through effects on tissue chemistry. Consequent changes in organic matter accumulation may alter marsh capacity to accommodate sea-level rise through vertical

  13. Possible use of a 3-D clinostat to analyze plant growth processes under microgravity conditions.

    PubMed

    Hoson, T; Kamisaka, S; Buchen, B; Sievers, A; Yamashita, M; Masuda, Y

    1996-01-01

    A three-dimensional (3-D) clinostat equipped with two rotation axes placed at right angles was constructed, and various growth processes of higher plants grown on this clinostat were compared with ground controls, with plants grown on the conventional horizontal clinostat, and with those under real microgravity in space. On the 3-D clinostat, cress roots developed a normal root cap and the statocytes showed the typical polar organization except a random distribution of statoliths. The structural features of clinostatted statocytes were fundamentally similar to those observed under real microgravity. The graviresponse of cress roots grown on the 3-D clinostat was the same as the control roots. On the 3-D clinostat, shoots and roots exhibited a spontaneous curvature as well as an altered growth direction. Such an automorphogenesis was sometimes exaggerated when plants were subjected to the horizontal rotation, whereas the curvature was suppressed on the vertical rotation. These discrepancies in curvature between the 3-D clinostat and the conventional ones appear to be brought about by the centrifugal force produced. Thus, the 3-D clinostat was proven as a useful device to simulate microgravity. PMID:11538636

  14. Influence of nonuniform magnetic fields on orientation of plant seedlings in microgravity conditions

    NASA Astrophysics Data System (ADS)

    Nechitailo, G. S.; Mashinsky, A. L.; Kuznetsov, A. A.; Chikov, V. M.; Kuznetsov, O. A.

    2001-01-01

    Experiments on the spatial behavior of the flax ( Linum usitatissimum, L.) seedlings in a nonuniform magnetic field were conducted on the orbital space stations «Salutå and «Mirå. This field can displace sensory organelles (statoliths) inside receptor cells and such displacement should cause a physiological reaction of the plant - tropistic curvature. Experiments were conducted in the custom-built «Magnetogravistatå facility, where seeds were germinated and grown for 3-4 days in a magnetic field with the dynamic factor grad(H 2/2)≈ 10 7 Oe 2/cm, then fixed on orbit and returned to Earth for analysis. It was found, that 93% of the seedlings were oriented in the field consistently with curvature in response to displacement of statoliths along the field gradient by ponderomotive magnetic forces, while control seedlings grew in the direction of the initial orientation of the seed. This suggests, that gravity receptors of plants recognized magnetic forces on statoliths as gravity, and that gravity stimulus can be substituted for plants by a force of a different physical nature.

  15. Phosphorus Concentrations in Above Ground Plant Biomass under Changing Climate Conditions

    NASA Astrophysics Data System (ADS)

    Selvin, C.; Paytan, A.; Roberts, K.

    2013-12-01

    The Jasper Ridge Global Change Experiment explores the effects of climate change on annual grasslands with different combinations of elevated or ambient levels of carbon dioxide, heat, precipitation, and nitrate deposition. The nested split-plot design allows for analysis of each variable, combinations of variables, and secondary effects. In this study, plant nutrient levels in homogenized above ground biomass are analyzed to assess the utility of this parameter as a tool to describe the response of an ecosystem to environmental changes. Total phosphorus concentrations showed considerable variability within treatment (n=8) and therefore no significant differences between treatments (n=16) is found. Carbon and nitrogen concentrations in bulk above ground biomass are being analyzed to determine nitrogen and carbon ratios and further elucidate the environmental response of phosphorus levels in plants to the modified parameters. P concentrations and elemental ratios will also be related to other parameters such as soil humidity, microbial biomass, enzyme activity, and plant diversity to determine the parameters influencing P content in the biomass.

  16. Activity of Medicinal Plant Extracts on Multiplication of Mycobacterium tuberculosis under Reduced Oxygen Conditions Using Intracellular and Axenic Assays.

    PubMed

    Bhatter, Purva D; Gupta, Pooja D; Birdi, Tannaz J

    2016-01-01

    Aim. Test the activity of selected medicinal plant extracts on multiplication of Mycobacterium tuberculosis under reduced oxygen concentration which represents nonreplicating conditions. Material and Methods. Acetone, ethanol and aqueous extracts of the plants Acorus calamus L. (rhizome), Ocimum sanctum L. (leaf), Piper nigrum L. (seed), and Pueraria tuberosa DC. (tuber) were tested on Mycobacterium tuberculosis H37Rv intracellularly using an epithelial cell (A549) infection model. The extracts found to be active intracellularly were further studied axenically under reducing oxygen concentrations. Results and Conclusions. Intracellular multiplication was inhibited ≥60% by five of the twelve extracts. Amongst these 5 extracts, in axenic culture, P. nigrum (acetone) was active under aerobic, microaerophilic, and anaerobic conditions indicating presence of multiple components acting at different levels and P. tuberosa (aqueous) showed bactericidal activity under microaerophilic and anaerobic conditions implying the influence of anaerobiosis on its efficacy. P. nigrum (aqueous) and A. calamus (aqueous and ethanol) extracts were not active under axenic conditions but only inhibited intracellular growth of Mycobacterium tuberculosis, suggesting activation of host defense mechanisms to mediate bacterial killing rather than direct bactericidal activity. PMID:26941797

  17. Activity of Medicinal Plant Extracts on Multiplication of Mycobacterium tuberculosis under Reduced Oxygen Conditions Using Intracellular and Axenic Assays

    PubMed Central

    Bhatter, Purva D.; Gupta, Pooja D.; Birdi, Tannaz J.

    2016-01-01

    Aim. Test the activity of selected medicinal plant extracts on multiplication of Mycobacterium tuberculosis under reduced oxygen concentration which represents nonreplicating conditions. Material and Methods. Acetone, ethanol and aqueous extracts of the plants Acorus calamus L. (rhizome), Ocimum sanctum L. (leaf), Piper nigrum L. (seed), and Pueraria tuberosa DC. (tuber) were tested on Mycobacterium tuberculosis H37Rv intracellularly using an epithelial cell (A549) infection model. The extracts found to be active intracellularly were further studied axenically under reducing oxygen concentrations. Results and Conclusions. Intracellular multiplication was inhibited ≥60% by five of the twelve extracts. Amongst these 5 extracts, in axenic culture, P. nigrum (acetone) was active under aerobic, microaerophilic, and anaerobic conditions indicating presence of multiple components acting at different levels and P. tuberosa (aqueous) showed bactericidal activity under microaerophilic and anaerobic conditions implying the influence of anaerobiosis on its efficacy. P. nigrum (aqueous) and A. calamus (aqueous and ethanol) extracts were not active under axenic conditions but only inhibited intracellular growth of Mycobacterium tuberculosis, suggesting activation of host defense mechanisms to mediate bacterial killing rather than direct bactericidal activity. PMID:26941797

  18. Volatile metabolites of higher plants cenoses as photosynthesizing LSS component under optimum conditions and temperature stress at different light intensities

    NASA Astrophysics Data System (ADS)

    Gitelson, J.; Tikhomirov, A.; Parshina, O.; Ushakova, S.; Kalacheva, G.

    One of major yet still poorly known functions of the photosynthesizing component in life support system (LSS) is to improve the quality of air through volatile emissions (VE) of plants capable of accumulating in closed volumes, interacting between themselves and having favorable or adverse impact on humans. In all likelihood, the effect of stress changing the functional condition of plants is to be accompanied with alteration in composition and quantity of VE. There are practically no works dealing with effect of such environmental factors as light intensity and elevated air temperature on qualitative and quantitative composition of VE by higher plants' cenoses. Meanwhile experimental modeling and investigation of stability of man-made human life support systems make this problem of very important. The aim of this work is to experimentally evaluate relationship between qualitative and quantitative composition of VE and the functional condition of wheat cenoses as the basic culture of LSS photosynthesizing component under normal conditions and under temperature stress against light of different intensity. Effect of elevated temperature 35 and 45°C (with the light intensity of 70, 150 or 240 W/m2 PAR) on photosynthesis, respiration, qualitative and quantitative composition of VE of wheat (Triticum aestuvi L., variety 232) cenoses was studied in the atmosphere of growth chambers. More than 20 volatile compounds (terpenoids - a pinene, +3 carene, limonene, benzene, a - and trans-caryophylene, a - and ?-terpinene, their derivatives, aromatic hydrocarbons, etc.) were qualitatively and quantitatively estimated by chromatomassspectroscopy (GC-MS). The light intensity of 240 W/m2 PAR at 35° increase, and at 45° - decrease of thermal stability of photosynthesis and respiration. Elevated temperatures resulted in non- uniform variation of the rate and direction of VE synthesis. VE was highest at irradiance 70 W/m 2 and lowest at 240 W/m2 and 35° . During the reparation

  19. Regulation of UVR8 photoreceptor dimer/monomer photo-equilibrium in Arabidopsis plants grown under photoperiodic conditions.

    PubMed

    Findlay, Kirsten M W; Jenkins, Gareth I

    2016-08-01

    The UV RESISTANCE LOCUS 8 (UVR8) photoreceptor specifically mediates photomorphogenic responses to UV-B. Photoreception induces dissociation of dimeric UVR8 into monomers to initiate responses. However, the regulation of dimer/monomer status in plants growing under photoperiodic conditions has not been examined. Here we show that UVR8 establishes a dimer/monomer photo-equilibrium in plants growing in diurnal photoperiods in both controlled environments and natural daylight. The photo-equilibrium is determined by the relative rates of photoreception and dark-reversion to the dimer. Experiments with mutants in REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 show that these proteins are crucial in regulating the photo-equilibrium because they promote reversion to the dimer. In plants growing in daylight, the UVR8 photo-equilibrium is most strongly correlated with low ambient fluence rates of UV-B (up to 1.5 μmol m(-2) s(-1) ), rather than higher fluence rates or the amount of photosynthetically active radiation. In addition, the rate of reversion of monomer to dimer is reduced at lower temperatures, promoting an increase in the relative level of monomer at approximately 8-10 °C. Thus, UVR8 does not behave like a simple UV-B switch under photoperiodic growth conditions but establishes a dimer/monomer photo-equilibrium that is regulated by UV-B and also influenced by temperature.

  20. Seasonal variations in roadside conditions and the performance of a gall-forming insect and its food plant.

    PubMed

    Martel, J

    1995-01-01

    A transplant experiment using potted plants was performed over two years in a field located along a heavily used highway to test for the effects of seasonal variations in roadside conditions on the performance of a gall-forming insect, Eurosta solidaginis Fitch, and its perennial host plant, Solidago altissima L. The experiment was designed to separate temporally the two major classes of road pollutants (air pollutants versus de-icing salt). The population density and survivorship of E. solidaginis were not affected by road-stressed goldenrods. However, gall-forming larvae had a greater biomass when they were grown on plants exposed to road air pollutants, although these effects were tempered by a simultaneous exposure to de-icing salt. The shoot growth of S. altissima was severely affected by road stress during each growing season but after two years the biomass of roots and rhizomes combined did not differ between the treatments. This experiment showed that the effects of air pollutants and de-icing salt on a gall-forming insect via stressed host plants are less than additive.

  1. Effect of host plants on developmental time and life table parameters of Carposina sasakii (Lepidoptera: Carposinidae) under laboratory conditions.

    PubMed

    Lei, Xihong; Li, Dingxu; Li, Zheng; Zalom, Frank G; Gao, Lingwang; Shen, Zuorui

    2012-04-01

    Studies were designed to examine the effects of host plants (apricot, Prunus armeniaca L.; plum, Prunus salicina L.; peach, Prunus persica L.; jujube, Zizyphus jujuba Will.; apple, Malus domestica Mill.; and pear, Pyrus sorotina Will) on the development and life table parameters of the peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae) under laboratory conditions. Peach fruit moth developed faster (12.48 d) and had the highest preimaginal survival rate (50.54%) on plum compared with the other host plants. Adult longevity was significantly longer on jujube for both female and male moths. Adult females from larvae reared on jujube and peach laid significantly greater numbers of eggs (214.50 and 197.94 eggs per female, respectively) compared with those reared on the other four host plants. Life-table parameters were calculated for each host plant and compared by jackknife procedures. The intrinsic rate of natural increase (r(m)) was significantly greatest on plum (0.1294 eggs per female per d), followed by jujube and apricot (0.1201 and 0.1128 eggs per female per d), respectively. Implications of the various measures of population performance are discussed.

  2. Macroelemental composition of cadmium stressed lettuce plants grown under conditions of intensive sulphur nutrition.

    PubMed

    Matraszek, Renata; Hawrylak-Nowak, Barbara; Chwil, Stanisław; Chwil, Mirosława

    2016-09-15

    Lettuce (Lactuca sativa L.) is moderately sensitive to cadmium (Cd) and shows high accumulation of this metal. Thus, this species is considered to be a good model for both identifying determinants controlling Cd accumulation in plant tissues and for developing breeding strategies aimed at limiting the accumulation of this metal in edible tissues. Simultaneously, lettuce is characterised by medium requirements for sulphur (S) - a macronutrient whose role is associated not only with proper growth and development, but also with stress tolerance. The common use of NPK fertilizers without sulphates (S-SO4) together with the progressive process of reducing emissions of S compounds to the natural environment may lead to deficiency of this element in plants. The present study evaluated the changes in macronutrient content and accumulation in Cd-stressed lettuce 'Justyna' supplied with different S doses. Four concentrations of Cd (0, 0.0002, 0.02 or 0.04 mM) and three levels of S applied in the form of S-SO4 (2, 6 or 9 mM S) were used. Cd exposure impaired the macronutrient balance and accumulation in lettuce. Intensive S nutrition to some extent alleviated Cd-induced toxicity. High S doses, especially 6 mM S, partially improved macronutrient status and restored the macronutrient balance. In Cd-stressed plants supplemented with additional S, an increase in root and shoot biomass and in the content of N, K and Mg was found, without significant changes in the Ca content. Simultaneously, the P and S contents in the biomass of both above- and underground organs remained unchanged. In the leaves, as opposite to the roots, intensive S nutrition reduced the accumulation of Cd. However, the foliar Cd concentration still exceeded the acceptable limits established for consumption. All the obtained results concerning the content of macronutrients and their ratios were referred, inter alia, to the standards i.e. the Diagnosis and Recommendation Integrated System (DRIS) norms.

  3. Data Mining and NIR Spectroscopy in Viticulture: Applications for Plant Phenotyping under Field Conditions

    PubMed Central

    Gutiérrez, Salvador; Tardaguila, Javier; Fernández-Novales, Juan; Diago, Maria P.

    2016-01-01

    Plant phenotyping is a very important topic in agriculture. In this context, data mining strategies may be applied to agricultural data retrieved with new non-invasive devices, with the aim of yielding useful, reliable and objective information. This work presents some applications of machine learning algorithms along with in-field acquired NIR spectral data for plant phenotyping in viticulture, specifically for grapevine variety discrimination and assessment of plant water status. Support vector machine (SVM), rotation forests and M5 trees models were built using NIR spectra acquired in the field directly on the adaxial side of grapevine leaves, with a non-invasive portable spectrophotometer working in the spectral range between 1600 and 2400 nm. The ν-SVM algorithm was used for the training of a model for varietal classification. The classifiers’ performance for the 10 varieties reached, for cross- and external validations, the 88.7% and 92.5% marks, respectively. For water stress assessment, the models developed using the absorbance spectra of six varieties yielded the same determination coefficient for both cross- and external validations (R2 = 0.84; RMSEs of 0.164 and 0.165 MPa, respectively). Furthermore, a variety-specific model trained only with samples of Tempranillo from two different vintages yielded R2 = 0.76 and RMSE of 0.16 MPa for cross-validation and R2 = 0.79, RMSE of 0.17 MPa for external validation. These results show the power of the combined use of data mining and non-invasive NIR sensing for in-field grapevine phenotyping and their usefulness for the wine industry and precision viticulture implementations. PMID:26891304

  4. Data Mining and NIR Spectroscopy in Viticulture: Applications for Plant Phenotyping under Field Conditions.

    PubMed

    Gutiérrez, Salvador; Tardaguila, Javier; Fernández-Novales, Juan; Diago, Maria P

    2016-01-01

    Plant phenotyping is a very important topic in agriculture. In this context, data mining strategies may be applied to agricultural data retrieved with new non-invasive devices, with the aim of yielding useful, reliable and objective information. This work presents some applications of machine learning algorithms along with in-field acquired NIR spectral data for plant phenotyping in viticulture, specifically for grapevine variety discrimination and assessment of plant water status. Support vector machine (SVM), rotation forests and M5 trees models were built using NIR spectra acquired in the field directly on the adaxial side of grapevine leaves, with a non-invasive portable spectrophotometer working in the spectral range between 1600 and 2400 nm. The ν-SVM algorithm was used for the training of a model for varietal classification. The classifiers' performance for the 10 varieties reached, for cross- and external validations, the 88.7% and 92.5% marks, respectively. For water stress assessment, the models developed using the absorbance spectra of six varieties yielded the same determination coefficient for both cross- and external validations (R² = 0.84; RMSEs of 0.164 and 0.165 MPa, respectively). Furthermore, a variety-specific model trained only with samples of Tempranillo from two different vintages yielded R² = 0.76 and RMSE of 0.16 MPa for cross-validation and R² = 0.79, RMSE of 0.17 MPa for external validation. These results show the power of the combined use of data mining and non-invasive NIR sensing for in-field grapevine phenotyping and their usefulness for the wine industry and precision viticulture implementations. PMID:26891304

  5. Recent condition of Fukushima-Daiichi nuclear plant accident in Japan

    NASA Astrophysics Data System (ADS)

    Ohnishi, Takeo

    2012-07-01

    Japanese government pronounced that the second step had been succeeded in the cooling down of the reactors on the middle of Dec 2011 at Fukushima-Daiichi nuclear power plant. In future, government aims to take out fuels from 4 reactors and shields their units. The nuclear power plants in Japan are gradually decreasing, because the checking for them has been performed and the permission of the re-start of them are difficult to be gained. On January 1st 2012, only 7 units are operating in Japan, though the about 54 units were set before the accident. At the end of December 2011, most radiations are emitted from cesium. The radioactivity in air and land around the plant was daily reported in newspaper. Government often gave the information about some RI-contamination in foods. They were taken off from the markets. At now stage, the most important project is the decontamination of radioactive materials from houses, schools, public facilities and industries. Government will newly classify three evacuation areas from April 2012. At the end of March, evacuees under 20 mSv/year possibly can go back their homes (evacuation-free area). The environmental doses will be depressed by decontamination under 10 mSv/year. At the range of 20-50 mSv, people will be controlled to live these area, they can go back their houses temporally (evacuation area). Over 50 mSv/year, however, people can go back house until 5 years at least (prohibited area). In new radiation limitation for a risk of human health, government made 100 mSv and 20 mSv for life span for one year, respectively. The aim of decontamination was set up to 10 mSv for 1 year and 5 mSv for next stage. A target at school is under1 mSv for children. Government accepted a new severe limitation per1 Kg at four groups; milk of baby (100 Bq) and milk (100 Bq), drinking water (10 Bq) and food (100 Bq). Tokyo electric Power Company and government should pay the sufficient compensation to evacuees. In future, they should keep health

  6. The ultrastructure and genetic traits of plants under the condition of hypobaric and hypoxia

    NASA Astrophysics Data System (ADS)

    Guo, Shuangsheng; Tang, Yongkang; Wang, Shulei; Cheng, Quanyong; Zhao, Qi

    This study analyzed the cellular, sub-cellular and molecular levels, particle composition and volume changes of Indian lettuce under the conditions of hypobaric and hypoxia. Firstly, in the hypobaric and hypoxia conditions, two kinds of sample showed a decrease in the num-ber of cells, the increase in volume and the deflation in nuclear size. Secondly, Significant changes of the chloroplast ultrastructure have taken place in the two conditions. Thirdly, in the hypoxia condition, the chloroplast grana lamellae fractured and aggregated, which caused the chloroplasts to enlarge, their lamellae to reduce,become vaguer and finally to disintegrate. Fourthly, the volume change and aggregation of the chloroplasts induced mitochondria to ap-proach the chloroplasts. Fifthly, cytoskeleton immunofluorescence positioning results showed that the microtubules had decreased in number, shortened in length and gathered in the vicinity of the nucleus. In addition, total leaf DNA-sequence alignment found no rbcl gene mutation in the extreme conditions. Keywords: Chloroplast Ultrastructure Cytoskeleton rbcl gene Indian lettuce

  7. The role of plant functional groups in methane dynamics in a boreal fen under pristine and water level drawdown conditions

    NASA Astrophysics Data System (ADS)

    Riutta, T.; Tuittila, E.-S.; Laine, J.

    2012-04-01

    Vegetation and hydrology are important controlling factors in peatland methane dynamics. Vegetation structures (i.e. species composition, physiognomy, density) and productivity are strongly interlinked with moisture conditions (water table level variation), and the methane flux is a result of the vegetation-water table interaction, rather than a direct effect of water table or vegetation. Therefore, observational studies in pristine peatlands have a limited ability to separate the effects of these factors. This study aimed to experimentally quantify the role of the fen ecosystem components - sedges, dwarf shrubs, Sphagnum mosses, and the underlying peat - in methane fluxes in control and experimental water table drawdown conditions and to separate the plant-mediated effects from the effect of altered water table level on methane fluxes. We carried out the experiment in a boreal nutrient-poor fen using two treatments: a vegetation component removal treatment with four levels and a water level treatment with two levels (control and a 15 cm water level draw down). We measured methane fluxes during four growing seasons using a static chamber technique. The first year was a calibration season preceding the water level drawdown treatment. Based on the vegetation removal treatments, plant-mediated fluxes comprised 75% of the total cumulative growing season methane flux (7.8 ± 0.83 g CH4 m-2 from June to September) in the control water level conditions. Sedge and Sphagnum moss mediated fluxes accounted for 48% and 27% of the total flux, respectively. The presence of dwarf shrubs, on the other hand, had a slightly attenuating effect on the fluxes. In water level drawdown conditions, fluxes were significantly lowered (cumulative growing season flux 0.12 ± 0.10 g CH4 m-2) and the presence / absence of the plant groups had hardly any effect on the fluxes. There was a tight, positive relationship between net ecosystem production and methane flux in the control conditions but

  8. Effects of Bauxsol and biosolids on soil conditions of acid-generating mine spoil for plant growth.

    PubMed

    Maddocks, G; Lin, C; McConchie, D

    2004-01-01

    Pot trials were conducted to examine the effects of Bauxsol and biosolids on mine soil conditions for plant growth. Sole application of biosolids did not significantly enhance the growth of the plant because the soils remained highly acidic with soluble concentrations of many metals in excess of toxic levels. Addition of Bauxsol generally resulted in an increase in biomass production by effectively correcting soil acidity and metal toxicity. However, sole application of Bauxsol did not enable meaningful establishment of the grass although the tree grew very well. The combination of Bauxsol and biosolids allowed the establishment of both the grass and the tree and therefore had the better effects on total biomass production, compared to the control and the sole treatments.

  9. Coagulant selection and sludge conditioning in a slaughterhouse wastewater treatment plant.

    PubMed

    Al-Mutairi, N Z; Hamoda, M F; Al-Ghusain, I

    2004-11-01

    Attempts were made in this study to examine the effectiveness of polymer addition to the aeration tank effluent prior to sludge flotation as practiced in a slaughterhouse wastewater treatment plant. The plant currently uses 10 mg/l of polymer prior to sludge flotation, but alternative, less-expensive, chemicals such as alum could be equally effective. Therefore, experiments were conducted using the Standard Jar test to determine the performance of both alum (Al2SO4.6H2O) and organic polymer. The dosages used for alum ranged between 0 and 1000 mg/l, whereas polymer dosages varied between 0 and 90 mg/l. The (optimal) removal efficiency for suspended solids in the mixed liquor was obtained at 400 mg/l for alum and 30 mg/l for polymer. It is evident that addition of alum or polymer results in significant removal of suspended solids reaching up to 99% for alum and 96% for polymer but alum produced a more compacted sludge. Removal of filterable COD was much lower in both cases since the chemicals used target the colloidal and suspended portion of the COD rather than the soluble (filterable) part of the COD. PMID:15246434

  10. Novel catalytic process for flue gas conditioning in electrostatic precipitators of coal-fired power plants.

    PubMed

    Zagoruiko, Andrey; Balzhinimaev, Bair; Vanag, Sergey; Goncharov, Vladimir; Lopatin, Sergey; Zykov, Alexander; Anichkov, Sergey; Zhukov, Yurii; Yankilevich, Vassily; Proskokov, Nikolay; Hutson, Nick

    2010-08-01

    One of the most important environmental protection problems for coal-fired power plants is prevention of atmospheric pollution of flying ash. The ash particles are typically removed from flue gases by means of electrostatic precipitators, for which the efficiency may be significantly increased by lowering the resistance of fly ash, which may be achieved by controlled addition of microamounts of sulfur trioxide (SO3) into the flue gases. This paper describes the novel technology for production of SO3 by sulfur dioxide (SO2) oxidation using the combined catalytic system consisting of conventional vanadium catalyst and novel platinum catalyst on the base of silicazirconia glass-fiber supports. This combination provides highly efficient SO, oxidation in a wide temperature range with achievement of high SO, conversion. The performed pilot tests have demonstrated reliable and stable operation, excellent resistance of the novel catalytic system to deactivation, and high overall efficiency of the proposed process. The scale of the plant was equivalent to the commercial prototype; therefore, no further scale-up of the oxidation process is required. PMID:20842940

  11. Inoculation effects of Pseudomonas putida, Gluconacetobacter azotocaptans, and Azospirillum lipoferum on corn plant growth under greenhouse conditions.

    PubMed

    Mehnaz, Samina; Lazarovits, George

    2006-04-01

    Alcohol production from corn is gaining importance in Ontario, Canada, and elsewhere. A major cost of corn production is the cost of chemical fertilizers and these continue to increase in price. The competitiveness of alcohol with fossil fuels depends on access to low-cost corn that allows growers to earn a sustainable income. In this study we set out to determine if we can identify root-associated microorganisms from Ontario-grown corn that can enhance the nutrient flow to corn roots, directly or indirectly, and help minimize the use of extraneous fertilizer. Bacteria were isolated from corn rhizosphere and screened for their capacity to enhance corn growth. The bacteria were examined for their ability to fix nitrogen, solubilize phosphate, and produce indole acetic acid (IAA) and antifungal substances on potato dextrose agar. Bacterial suspensions were applied to pregerminated seed of four corn varieties (39D82, 39H84, 39M27, and 39T68) planted in sterilized sand and unsterilized cornfield soil. The plants were grown under greenhouse conditions for 30 days. Three isolates were identified as having growth-promoting effect. These bacteria were identified as to species by biochemical tests, fatty acid profiles, and 16S rDNA sequence analysis. Corn rhizosphere isolates, Gluconacetobacter azotocaptans DS1, Pseudomonas putida CQ179, and Azospirillum lipoferum N7, provided significant plant growth promotion expressed as increased root/shoot weight when compared to uninoculated plants, in sand and/or soil. All strains except P. putida CQ179 were capable of nitrogen fixation and IAA production. Azospirillum brasilense, however, produced significantly more IAA than the other isolates. Although several of the strains were also able to solubilize phosphate and produce metabolites inhibitory to various fungal pathogens, these properties are not considered as contributing to growth promotion under the conditions used in this study. These bacteria will undergo field tests for

  12. Density measurements as a condition monitoring approach for following the aging of nuclear power plant cable materials

    NASA Astrophysics Data System (ADS)

    Gillen, K. T.; Celina, M.; Clough, R. L.

    1999-10-01

    Monitoring changes in material density has been suggested as a potentially useful condition monitoring (CM) method for following the aging of cable jacket and insulation materials in nuclear power plants. In this study, we compare density measurements and ultimate tensile elongation results versus aging time for most of the important generic types of commercial nuclear power plant cable materials. Aging conditions, which include thermal-only, as well as combined radiation plus thermal, were chosen such that potentially anomalous effects caused by diffusion-limited oxidation (DLO) are unimportant. The results show that easily measurable density increases occur in most important cable materials. For some materials and environments, the density change occurs at a fairly constant rate throughout the mechanical property lifetime. For cases involving so-called induction-time behavior, density increases are slow to moderate until after the induction time, at which point they begin to increase dramatically. In other instances, density increases rapidly at first, then slows down. The results offer strong evidence that density measurements, which reflect property changes under both radiation and thermal conditions, could represent a very useful CM approach.

  13. Macroelemental composition of cadmium stressed lettuce plants grown under conditions of intensive sulphur nutrition.

    PubMed

    Matraszek, Renata; Hawrylak-Nowak, Barbara; Chwil, Stanisław; Chwil, Mirosława

    2016-09-15

    Lettuce (Lactuca sativa L.) is moderately sensitive to cadmium (Cd) and shows high accumulation of this metal. Thus, this species is considered to be a good model for both identifying determinants controlling Cd accumulation in plant tissues and for developing breeding strategies aimed at limiting the accumulation of this metal in edible tissues. Simultaneously, lettuce is characterised by medium requirements for sulphur (S) - a macronutrient whose role is associated not only with proper growth and development, but also with stress tolerance. The common use of NPK fertilizers without sulphates (S-SO4) together with the progressive process of reducing emissions of S compounds to the natural environment may lead to deficiency of this element in plants. The present study evaluated the changes in macronutrient content and accumulation in Cd-stressed lettuce 'Justyna' supplied with different S doses. Four concentrations of Cd (0, 0.0002, 0.02 or 0.04 mM) and three levels of S applied in the form of S-SO4 (2, 6 or 9 mM S) were used. Cd exposure impaired the macronutrient balance and accumulation in lettuce. Intensive S nutrition to some extent alleviated Cd-induced toxicity. High S doses, especially 6 mM S, partially improved macronutrient status and restored the macronutrient balance. In Cd-stressed plants supplemented with additional S, an increase in root and shoot biomass and in the content of N, K and Mg was found, without significant changes in the Ca content. Simultaneously, the P and S contents in the biomass of both above- and underground organs remained unchanged. In the leaves, as opposite to the roots, intensive S nutrition reduced the accumulation of Cd. However, the foliar Cd concentration still exceeded the acceptable limits established for consumption. All the obtained results concerning the content of macronutrients and their ratios were referred, inter alia, to the standards i.e. the Diagnosis and Recommendation Integrated System (DRIS) norms. PMID

  14. Salicornia as a crop plant in temperate regions: selection of genetically characterized ecotypes and optimization of their cultivation conditions.

    PubMed

    Singh, Devesh; Buhmann, Anne K; Flowers, Tim J; Seal, Charlotte E; Papenbrock, Jutta

    2014-01-01

    Rising sea levels and salinization of groundwater due to global climate change result in fast-dwindling sources of freshwater. Therefore, it is important to find alternatives to grow food crops and vegetables. Halophytes are naturally evolved salt-tolerant plants that are adapted to grow in environments that inhibit the growth of most glycophytic crop plants substantially. Members of the Salicornioideae are promising candidates for saline agriculture due to their high tolerance to salinity. Our aim was to develop genetically characterized lines of Salicornia and Sarcocornia for further breeding and to determine optimal cultivation conditions. To obtain a large and diverse genetic pool, seeds were collected from different countries and ecological conditions. The external transcribed spacer (ETS) sequence of 62 Salicornia and Sarcocornia accessions was analysed: ETS sequence data showed a clear distinction between the two genera and between different Salicornia taxa. However, in some cases the ETS was not sufficiently variable to resolve morphologically distinct species. For the determination of optimal cultivation conditions, experiments on germination, seedling establishment and growth to a harvestable size were performed using different accessions of Salicornia spp. Experiments revealed that the percentage germination was greatest at lower salinities and with temperatures of 20/10 °C (day/night). Salicornia spp. produced more harvestable biomass in hydroponic culture than in sand culture, but the nutrient concentration requires optimization as hydroponically grown plants showed symptoms of stress. Salicornia ramosissima produced more harvestable biomass than Salicornia dolichostachya in artificial sea water containing 257 mM NaCl. Based on preliminary tests on ease of cultivation, gain in biomass, morphology and taste, S. dolichostachya was investigated in more detail, and the optimal salinity for seedling establishment was found to be 100 mM. Harvesting of S

  15. Malate as a key carbon source of leaf dark-respired CO2 across different environmental conditions in potato plants

    PubMed Central

    Lehmann, Marco M.; Rinne, Katja T.; Blessing, Carola; Siegwolf, Rolf T. W.; Buchmann, Nina; Werner, Roland A.

    2015-01-01

    Dissimilation of carbon sources during plant respiration in support of metabolic processes results in the continuous release of CO2. The carbon isotopic composition of leaf dark-respired CO2 (i.e. δ 13 C R) shows daily enrichments up to 14.8‰ under different environmental conditions. However, the reasons for this 13C enrichment in leaf dark-respired CO2 are not fully understood, since daily changes in δ13C of putative leaf respiratory carbon sources (δ 13 C RS) are not yet clear. Thus, we exposed potato plants (Solanum tuberosum) to different temperature and soil moisture treatments. We determined δ 13 C R with an in-tube incubation technique and δ 13 C RS with compound-specific isotope analysis during a daily cycle. The highest δ 13 C RS values were found in the organic acid malate under different environmental conditions, showing less negative values compared to δ 13 C R (up to 5.2‰) and compared to δ 13 C RS of soluble carbohydrates, citrate and starch (up to 8.8‰). Moreover, linear relationships between δ 13 C R and δ 13 C RS among different putative carbon sources were strongest for malate during daytime (r2=0.69, P≤0.001) and nighttime (r2=0.36, P≤0.001) under all environmental conditions. A multiple linear regression analysis revealed δ 13 C RS of malate as the most important carbon source influencing δ 13 C R. Thus, our results strongly indicate malate as a key carbon source of 13C enriched dark-respired CO2 in potato plants, probably driven by an anapleurotic flux replenishing intermediates of the Krebs cycle. PMID:26139821

  16. Malate as a key carbon source of leaf dark-respired CO2 across different environmental conditions in potato plants.

    PubMed

    Lehmann, Marco M; Rinne, Katja T; Blessing, Carola; Siegwolf, Rolf T W; Buchmann, Nina; Werner, Roland A

    2015-09-01

    Dissimilation of carbon sources during plant respiration in support of metabolic processes results in the continuous release of CO2. The carbon isotopic composition of leaf dark-respired CO2 (i.e. δ (13) C R ) shows daily enrichments up to 14.8‰ under different environmental conditions. However, the reasons for this (13)C enrichment in leaf dark-respired CO2 are not fully understood, since daily changes in δ(13)C of putative leaf respiratory carbon sources (δ (13) C RS ) are not yet clear. Thus, we exposed potato plants (Solanum tuberosum) to different temperature and soil moisture treatments. We determined δ (13) C R with an in-tube incubation technique and δ (13) C RS with compound-specific isotope analysis during a daily cycle. The highest δ (13) C RS values were found in the organic acid malate under different environmental conditions, showing less negative values compared to δ (13) C R (up to 5.2‰) and compared to δ (13) C RS of soluble carbohydrates, citrate and starch (up to 8.8‰). Moreover, linear relationships between δ (13) C R and δ (13) C RS among different putative carbon sources were strongest for malate during daytime (r(2)=0.69, P≤0.001) and nighttime (r(2)=0.36, P≤0.001) under all environmental conditions. A multiple linear regression analysis revealed δ (13) C RS of malate as the most important carbon source influencing δ (13) C R . Thus, our results strongly indicate malate as a key carbon source of (13)C enriched dark-respired CO2 in potato plants, probably driven by an anapleurotic flux replenishing intermediates of the Krebs cycle.

  17. Salicornia as a crop plant in temperate regions: selection of genetically characterized ecotypes and optimization of their cultivation conditions

    PubMed Central

    Singh, Devesh; Buhmann, Anne K.; Flowers, Tim J.; Seal, Charlotte E.; Papenbrock, Jutta

    2014-01-01

    Rising sea levels and salinization of groundwater due to global climate change result in fast-dwindling sources of freshwater. Therefore, it is important to find alternatives to grow food crops and vegetables. Halophytes are naturally evolved salt-tolerant plants that are adapted to grow in environments that inhibit the growth of most glycophytic crop plants substantially. Members of the Salicornioideae are promising candidates for saline agriculture due to their high tolerance to salinity. Our aim was to develop genetically characterized lines of Salicornia and Sarcocornia for further breeding and to determine optimal cultivation conditions. To obtain a large and diverse genetic pool, seeds were collected from different countries and ecological conditions. The external transcribed spacer (ETS) sequence of 62 Salicornia and Sarcocornia accessions was analysed: ETS sequence data showed a clear distinction between the two genera and between different Salicornia taxa. However, in some cases the ETS was not sufficiently variable to resolve morphologically distinct species. For the determination of optimal cultivation conditions, experiments on germination, seedling establishment and growth to a harvestable size were performed using different accessions of Salicornia spp. Experiments revealed that the percentage germination was greatest at lower salinities and with temperatures of 20/10 °C (day/night). Salicornia spp. produced more harvestable biomass in hydroponic culture than in sand culture, but the nutrient concentration requires optimization as hydroponically grown plants showed symptoms of stress. Salicornia ramosissima produced more harvestable biomass than Salicornia dolichostachya in artificial sea water containing 257 mM NaCl. Based on preliminary tests on ease of cultivation, gain in biomass, morphology and taste, S. dolichostachya was investigated in more detail, and the optimal salinity for seedling establishment was found to be 100 mM. Harvesting of S

  18. [Promising technique of mineral supply organization for plants in the condition of microgravity].

    PubMed

    Berkovich, Iu A; Krivobok, A S; Krivobok, N M; Smolianina, S O

    2014-01-01

    The proposed system of automated nutrient solution preparation for plant cultivation in microgravity consists of an ion-exchange fabric artificial soil (AS) as a root-inhabited medium, a pack with slow release fertilizer as the main source of nitrogen, phosphorus and potassium and a cartridge with a granular mineral-rich ionite as a source of calcium, magnesium, sulphur and iron. Experiments proved that fabric AS BIONA-V3 is capable to stabilize pH of the substrate solution within the range of 6.0 to 6.6 favorable to the majority of vegetable cultures. The experimental data attested suitability of this technique of water forcing through mineral-containing packs to automate nutrient solution preparation for crops cultivated in space greenhouses, and to minimize the stock of fabric AS onboard the space vehicle.

  19. [Promising technique of mineral supply organization for plants in the condition of microgravity].

    PubMed

    Berkovich, Iu A; Krivobok, A S; Krivobok, N M; Smolianina, S O

    2014-01-01

    The proposed system of automated nutrient solution preparation for plant cultivation in microgravity consists of an ion-exchange fabric artificial soil (AS) as a root-inhabited medium, a pack with slow release fertilizer as the main source of nitrogen, phosphorus and potassium and a cartridge with a granular mineral-rich ionite as a source of calcium, magnesium, sulphur and iron. Experiments proved that fabric AS BIONA-V3 is capable to stabilize pH of the substrate solution within the range of 6.0 to 6.6 favorable to the majority of vegetable cultures. The experimental data attested suitability of this technique of water forcing through mineral-containing packs to automate nutrient solution preparation for crops cultivated in space greenhouses, and to minimize the stock of fabric AS onboard the space vehicle. PMID:25163340

  20. Influence of scale deposition on cathodic-protection performance in desalination plant conditions.

    PubMed

    Hodgkiess, T; Najm-Mohammed, N A

    2004-01-01

    This paper describes an investigation into the interrelationships between the performance of an impressed current cathodic protection (CP) system and the deposition of scale compounds in a seawater pipe system. Some experiments were conducted on a laboratory set-up but the emphasis was on tests on a 0.25 m diameter steel pipe fed by seawater flowing to a thermal desalination plant. The experimental approach involved monitoring the CP current as a function of time at various set potentials and correlating this data with evidence from visual inspection of the pipe-wall surfaces and small probe specimens. The influences of control potential and seawater flow rate at temperatures of 25-35 degrees C were studied. Selected scale samples were subjected to examination by scanning electron microscopy and X-ray diffraction. The overall findings are discussed in terms of fundamental scale/CP-operation interactions and aspects relevant to practical operation of CP systems on seawater pipe installations.

  1. Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant

    SciTech Connect

    Kumar, Rajeeva; Kumar, Aditya; Dai, Dan; Seenumani, Gayathri; Down, John; Lopez, Rodrigo

    2012-12-31

    This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve

  2. Moisture Absorption of Plant Fiber under Annealed, Bleached and Mercerized Condition

    NASA Astrophysics Data System (ADS)

    Saikia, Dip

    2010-06-01

    The water absorptions behaviors of the okra fibers, which are available in north east India, were studied under ambient, annealed, bleached and mercerized conditions by using ordinary gravimetric absorption method. The gains in moisture content in the fibers due to water absorption as well as their capillarity at constant relative humidity were measured as a function of exposure time. In order to ascertain the environment factor of utility of the fibers, the moisture regain of the fibers were determined at different relative air humidity. The water yielding capacity of okra fibers was also determined in order to understand their drying properties. The diffusion coefficients of the sorption process of the fibers under ambient, annealed, bleached and mercerized conditions were estimated.

  3. Moisture Absorption of Plant Fiber under Annealed, Bleached and Mercerized Condition

    SciTech Connect

    Saikia, Dip

    2010-06-29

    The water absorptions behaviors of the okra fibers, which are available in north east India, were studied under ambient, annealed, bleached and mercerized conditions by using ordinary gravimetric absorption method. The gains in moisture content in the fibers due to water absorption as well as their capillarity at constant relative humidity were measured as a function of exposure time. In order to ascertain the environment factor of utility of the fibers, the moisture regain of the fibers were determined at different relative air humidity. The water yielding capacity of okra fibers was also determined in order to understand their drying properties. The diffusion coefficients of the sorption process of the fibers under ambient, annealed, bleached and mercerized conditions were estimated.

  4. Plant epiphytism in semiarid conditions revealed the influence of habitat and climate variables on AM fungi communities distribution

    NASA Astrophysics Data System (ADS)

    Torrecillas, Emma; Torres, Pilar; Díaz, Gisela; del Mar Alguacil, Maria; Querejeta, Jose Ignacio; García, Fuensanta; Roldán, Antonio

    2014-05-01

    In semiarid Mediterranean ecosystems epiphytic plant species are practically absent and only some species of palm-trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study we focused in Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils, Our aim was to determine the possible presence of AMF in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AM fungi as determined by microscopic observation, all epiphytic and terrestrial samples analysed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF OTUs. The AMF community composition was clearly different between epiphytic and terrestrial root samples and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats.

  5. Effects on the microbiological condition of product of decontaminating treatments routinely applied to carcasses at beef packing plants.

    PubMed

    Gill, C O

    2009-08-01

    Reports on the microbiological effects of decontaminating treatments routinely applied to carcasses at beef packing plants indicate that washing before skinning may reduce the numbers of enteric bacteria transferred from the hide to meat. Washing skinned carcasses and/or dressed sides can reduce the numbers of aerobes and Escherichia coli by about 1 log unit, and pasteurizing sides with steam or hot water can reduce their numbers by > 1 or > 2 log units, respectively. Spraying with 2% lactic acid, 2% acetic acid, or 200 ppm of peroxyacetic acid can reduce the numbers of aerobes and E. coli by about 1 log, but such treatments can be ineffective if solutions are applied in inadequate quantities or to meat surfaces that are wet after washing. Trimming and vacuum cleaning with or without spraying with hot water may be largely ineffective for improving the microbiological conditions of carcasses. When contamination of meat during carcass dressing is well controlled and carcasses are subjected to effective decontaminating treatments, the numbers of E. coli on dressed carcasses can be < 1 CFU/ 1,000 cm2. However, meat can be recontaminated during carcass breaking with E. coli from detritus that persists in fixed and personal equipment. The adoption at all packing plants of the carcass-dressing procedures and decontaminating treatments used at some plants to obtain carcasses that meet a very high microbiological standard should be encouraged, and means for limiting recontamination of product during carcass breaking and for decontaminating trimmings and other beef products should be considered.

  6. Genetic diversity of plant growth promoting rhizobacteria isolated from rhizospheric soil of wheat under saline condition.

    PubMed

    Upadhyay, Sudhir K; Singh, Devendra P; Saikia, Ratul

    2009-11-01

    In this study, a total of 130 rhizobacteria was isolated from a saline infested zone of wheat rhizosphere, and screened for plant growth promoting (PGP) traits at higher salt (NaCl) concentrations (2, 4, 6, and 8%). The results revealed that 24 rhizobacterial isolates were tolerant at 8% NaCl. Although all the 24 salt tolerable isolates produced indole-3-acetic acid (IAA), while 10 isolates solubilized phosphorus, eight produced siderophore, and six produced gibberellin. However, only three isolates showed the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Diversity was analyzed through 16S rDNA-RFLP, and of these isolates with three tetra cutter restriction enzymes (HaeIII, AluI, and MspI), the representative cluster groups were identified by 16S rDNA sequencing. Bacillus and Bacillus-derived genera were dominant which showed PGP attributes at 8% NaCl concentration. Out of 24 isolates, nitrogen fixing ability (nif H gene) was detected in the two isolates, SU18 (Arthrobacter sp.) and SU48.

  7. Positive effects of temperature and growth conditions on enzymatic and antioxidant status in lettuce plants.

    PubMed

    Boo, Hee-Ock; Heo, Buk-Gu; Gorinstein, Shela; Chon, Sang-Uk

    2011-10-01

    The contents of two bioactive compounds (polyphenols and flavonoids) and their antioxidant and enzyme activities were determined in the leaves of six lettuce (Latuca sativa L.) cultivars subjected to 4 different day/night temperatures for 6 weeks. The total polyphenol and anthocyanin contents and the corresponding antioxidant activities were the highest at 13/10°C and 20/13°C, followed by 25/20°C and 30/25°C. The enzymatic activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) were also the highest at low day/night temperatures, but the peroxidase (POD) activity was decreased at low day/night temperatures and increased at high day/night temperatures. The most significant positive correlation existed between anthocyanin content and PPO activity, total polyphenols and their antioxidant activities. The results showed that at relatively low temperatures, lettuce plants have a high antioxidant and enzymatic status. These results provide additional information for the lettuce growers. PMID:21889055

  8. How Very-Long-Chain Fatty Acids Could Signal Stressful Conditions in Plants?

    PubMed Central

    De Bigault Du Granrut, Antoine; Cacas, Jean-Luc

    2016-01-01

    Although encountered in minor amounts in plant cells, very-long-chain fatty acids exert crucial functions in developmental processes. When their levels are perturbed by means of genetic approaches, marked phenotypic consequences that range from severe growth retardation to embryo lethality was indeed reported. More recently, a growing body of findings has also accumulated that points to a potential role for these lipids as signals in governing both biotic and abiotic stress outcomes. In the present work, we discuss the latter theory and explore the ins and outs of very-long-chain fatty acid-based signaling in response to stress, with an attempt to reconcile two supposedly antagonistic parameters: the insoluble nature of fatty acids and their signaling function. To explain this apparent dilemma, we provide new interpretations of pre-existing data based on the fact that sphingolipids are the main reservoir of very-long-chain fatty acids in leaves. Thus, three non-exclusive, molecular scenarii that involve these lipids as membrane-embedded and free entities are proposed. PMID:27803703

  9. Electrical equipment performance under severe accident conditions (BWR/Mark 1 plant analysis): Summary report

    SciTech Connect

    Bennett, P.R.; Kolaczkowski, A.M.; Medford, G.T.

    1986-09-01

    The purpose of the Performance Evaluation of Electrical Equipment during Severe Accident States Program is to determine the performance of electrical equipment, important to safety, under severe accident conditions. In FY85, a method was devised to identify important electrical equipment and the severe accident environments in which the equipment was likely to fail. This method was used to evaluate the equipment and severe accident environments for Browns Ferry Unit 1, a BWR/Mark I. Following this work, a test plan was written in FY86 to experimentally determine the performance of one selected component to two severe accident environments.

  10. Species and tissue type regulate long-term decomposition of brackish marsh plants grown under elevated CO2 conditions

    USGS Publications Warehouse

    Jones, Joshua A; Cherry, Julia A; Mckee, Karen L.

    2016-01-01

    Organic matter accumulation, the net effect of plant production and decomposition, contributes to vertical soil accretion in coastal wetlands, thereby playing a key role in whether they keep pace with sea-level rise. Any factor that affects decomposition may affect wetland accretion, including atmospheric CO2 concentrations. Higher CO2 can influence decomposition rates by altering plant tissue chemistry or by causing shifts in plant species composition or biomass partitioning. A combined greenhouse-field experiment examined how elevated CO2 affected plant tissue chemistry and subsequent decomposition of above- and belowground tissues of two common brackish marsh species, Schoenoplectus americanus (C3) and Spartina patens (C4). Both species were grown in monoculture and in mixture under ambient (350-385 μL L-1) or elevated (ambient + 300 μL L-1) atmospheric CO2 conditions, with all other growth conditions held constant, for one growing season. Above- and belowground tissues produced under these treatments were decomposed under ambient field conditions in a brackish marsh in the Mississippi River Delta, USA. Elevated CO2 significantly reduced nitrogen content of S. americanus, but not sufficiently to affect subsequent decomposition. Instead, long-term decomposition (percent mass remaining after 280 d) was controlled by species composition and tissue type. Shoots of S. patens had more mass remaining (41 ± 2%) than those of S. americanus (12 ± 2 %). Belowground material decomposed more slowly than that placed aboveground (62 ± 1% vs. 23 ± 3% mass remaining), but rates belowground did not differ between species. Increases in atmospheric CO2concentration will likely have a greater effect on overall decomposition in this brackish marsh community through shifts in species dominance or biomass allocation than through effects on tissue chemistry. Consequent changes in organic matter accumulation may alter marsh capacity to accommodate sea-level rise

  11. Selecting indicators of soil, microbial, and plant conditions to understand ecological changes in Georgia pine forests

    SciTech Connect

    Dale, Virginia H; Garten Jr, Charles T; Wolfe, Amy K; Sobek, Edward A

    2008-11-01

    Characterizing how resource use and management activities affect ecological conditions is necessary to document and understand anthropogenic changes in ecological systems. Resource managers on military installations have the delicate task of balancing the training needs of soldiers effectively with the need to maintain a high quality of ecological conditions. This study considers ways that ecological indicators can provide information on impacts that training has on environmental characteristics that occur at different scales and in different sectors of the environment. The characteristics examined include soil chemistry, soil microbes, and vegetation. A discriminant function analysis was conducted to determine whether ecological indicators could differentiate among different levels of military use. A combination of 10 indicators explained 90% of the variation among plots from five different military use levels. Results indicated that an appropriate suite of ecological indicators for military resource managers includes soil, microbial, and vegetation characteristics. Since many of these indicators are related, managers at this location potentially have freedom to choose indicators that are relatively easy to measure, without sacrificing information.

  12. Impacts of alien invasive plants on soil nutrients are correlated with initial site conditions in NW Europe.

    PubMed

    Dassonville, Nicolas; Vanderhoeven, Sonia; Vanparys, Valérie; Hayez, Mathieu; Gruber, Wolf; Meerts, Pierre

    2008-08-01

    Alien invasive plants are capable of modifying ecosystem function. However, it is difficult to make generalisations because impacts often appear to be species- and site-specific. In this study, we examined the impacts of seven highly invasive plant species in NW Europe (Fallopia japonica, Heracleum mantegazzianum, Impatiens glandulifera, Prunus serotina, Rosa rugosa, Senecio inaequidens, Solidago gigantea) on nutrient pools in the topsoil and the standing biomass. We tested if the impacts follow predictable patterns, across species and sites or, alternatively, if they are entirely idiosyncratic. To that end, we compared invaded and adjacent uninvaded plots in a total of 36 sites with widely divergent soil chemistry and vegetation composition. For all species, invaded plots had increased aboveground biomass and nutrient stocks in standing biomass compared to uninvaded vegetation. This suggests that enhanced nutrient uptake may be a key trait of highly invasive plant species. The magnitude and direction of the impact on topsoil chemical properties were strongly site-specific. A striking finding is that the direction of change in soil properties followed a predictable pattern. Thus, strong positive impacts (higher topsoil nutrient concentrations in invaded plots compared to uninvaded ones) were most often found in sites with initially low nutrient concentrations in the topsoil, while negative impacts were generally found under the opposite conditions. This pattern was significant for potassium, magnesium, phosphorus, manganese and nitrogen. The particular site-specific pattern in the impacts that we observed provides the first evidence that alien invasive species may contribute to a homogenisation of soil conditions in invaded landscapes. PMID:18491146

  13. Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Miller, R.L.; Fujii, R.

    2010-01-01

    Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates. ?? Springer Science+Business Media B.V. 2009.

  14. Assessment of actual transpiration rate in olive tree field combining sap-flow, leaf area index and scintillometer measurements

    NASA Astrophysics Data System (ADS)

    Agnese, C.; Cammalleri, C.; Ciraolo, G.; Minacapilli, M.; Provenzano, G.; Rallo, G.; de Bruin, H. A. R.

    2009-09-01

    Models to estimate the actual evapotranspiration (ET) in sparse vegetation area can be fundamental for agricultural water managements, especially when water availability is a limiting factor. Models validation must be carried out by considering in situ measurements referred to the field scale, which is the relevant scale of the modelled variables. Moreover, a particular relevance assumes to consider separately the components of plant transpiration (T) and soil evaporation (E), because only the first is actually related to the crop stress conditions. Objective of the paper was to assess a procedure aimed to estimate olive trees actual transpiration by combining sap flow measurements with the scintillometer technique at field scale. The study area, located in Western Sicily (Italy), is mainly cultivated with olive crop and is characterized by typical Mediterranean semi-arid climate. Measurements of sap flow and crop actual evapotranspiration rate were carried out during 2008 irrigation season. Crop transpiration fluxes, measured on some plants by means of sap flow sensors, were upscaled considering the leaf area index (LAI). The comparison between evapotranspiration values, derived by displaced-beam small-aperture scintillometer (DBSAS-SLS20, Scintec AG), with the transpiration fluxes obtained by the sap flow sensors, also allowed to evaluate the contribute of soil evaporation in an area characterized by low vegetation coverage.

  15. Edaphic and light conditions of sympatric plant morphotypes in western Amazonia

    PubMed Central

    2014-01-01

    Abstract Here I present a dataset of edaphic and light conditions associated with the occurrence of sympatric morphotypes of Geonoma macrostachys (Arecaceae/Palmae), a candidate case study from Amazonia hypothesized to have evolved under ecological speciation. Transects were established in three lowland rainforests in Peru, and the abundance of each local morphotype of this species was recorded in a total area of 4.95 hectares. Composite soil samples and hemispherical photographs were taken along the transects were the species occurred to obtain information on soil nutrients, soil texture, and indirect measurements of light availability. The raw and summary tables disclose the characteristics of each study site and habitats within them, which could be useful to soil scientists, ecologists, and conservationists engaged in similar research activities or meta-analyses in Amazonia. PMID:24891831

  16. 7 CFR 330.203 - Action on applications for permits to move plant pests; form of and conditions in permits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FEDERAL PLANT PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of Plant... 7 Agriculture 5 2013-01-01 2013-01-01 false Action on applications for permits to move plant...

  17. 7 CFR 330.203 - Action on applications for permits to move plant pests; form of and conditions in permits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FEDERAL PLANT PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of Plant... 7 Agriculture 5 2010-01-01 2010-01-01 false Action on applications for permits to move plant...

  18. 63. VIEW OF AUTOTRANSFERS. THE ACTUAL AUTOTRANSFERS ARE ENCLOSED IN ...

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

    63. VIEW OF AUTOTRANSFERS. THE ACTUAL AUTOTRANSFERS ARE ENCLOSED IN THE OIL FILLED CYLINDERS ON THE RIGHT OF THE PHOTOGRAPH. THESE ELECTRICAL DEVICES BOOSTED THE GENERATOR OUTPUT OF 11,000 VOLTS TO 22,000 VOLTS PRIOR TO TRANSMISSION OUT TO THE MAIN FEEDER LINES. A SPARE INNER UNIT IS CONTAINED IN THE METAL BOX AT THE LEFT OF THE PHOTOGRAPH. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  19. Aftereffect conditions of prolonged space flight on physiological and biochemical processes and plant resistance Lycopersicon esculentum Mill. to pathogens

    NASA Astrophysics Data System (ADS)

    Mishchenko, Lidiya

    2016-07-01

    Tomatoes (Lycopersicon esculentum Mill.) - one of the most popular vegetables in Ukraine, they are a valuable product of therapeutic and dietetic foods because they contain a significant amount of nutrients and essential to the human body minerals and vitamins, but by the content of carotenoids - lycopene and β-carotene - is a powerful antioxidant. Therefore, tomato plants can be used successfully to astronauts on long space flights. We aftereffect was studied factors of space flight on the variety of tomato seeds Mir-1, which lasted (6 years) were on an orbital space station "Mir". Then, also after long-term storage in 2011, seeds were sown in the laboratory and received seedlings grown in field conditions Kiev region. The resulting seeds of the tomato crop in 2011 ("Space" and still) we used in our subsequent field studies in Kyiv and Poltava regions. We have previously shown that the "space" seeds had shown in 2011-2012 increased resistance to viruses PVY and PVM natural infectious background. Therefore, it is necessary continue the investigation and started to observe in future years, including 2015 and to analyze the results obtained. Because plants grown constantly in the field natural infectious background, there was a high probability of their defeat pathogens of different nature, including viruses. The works of many authors proved reduce the concentration of carotene and lycopene in tomatoes with the defeat of viruses (Raithak, 2012). In addition, the control plants were observed symptoms of such that is a viral infection, namely in 2011 - leaves curl in 2012 - except leaves curl and even mosaics. The research results were confirmed in 2013, namely on the plants of "space" seed no symptoms of, and in control - detection of potato virus Y (method RT-PCR) and symptoms of leaf curl and mosaic. During the bearing samples were taken leaves of the options and experiment conducted determination of photosynthetic pigments. It should be emphasized that in plant

  20. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern

    USGS Publications Warehouse

    Huber, Ann; Das, Adrian; Wenk, Rebecca; Haultain, Sylvia

    2013-01-01

    Database (CNDDB 2010a). There are an additional 66 taxa not formally listed by CNDDB that are recognized as having special status because their distribution is restricted to the Sierra Nevada. Special status plants are distributed throughout the two parks and inhabit a wide range of environments along the length of the elevation gradient that characterizes these parks. Ideally, we would assess the condition (status and trends) of each of the taxa on the SEKI special status plant list, documenting current population sizes, demographic rates and demographic trends. We would also hope to quantify the effects of individual stressors on each species based on existing monitoring and research. However, no data are available for most of the species on the special status plant list. For those few species (12 herbaceous species and two tree species) for which we possess some change over time information, the data are not adequate to make a competent assessment. Note that we have not explored the tree demographic information in any detail, as is covered in the NRCA Intact Forest/Five Needle Pines and Sequoia chapters. In general, we are unable to present an ‗integrity‘ metric for special status species in the parks, since the data to quantify the condition of each species in such a manner is not available. In contrast, the park does possess substantial data describing biodiversity in the parks. Therefore, our analysis focuses on describing the distribution and rarity of special status plants within the parks, with a particular focus on assessing the spatial distribution of species richness. We hope that such information will prove useful to park managers in determining which areas in the parks merit the most attention (for example in developing monitoring protocols). We also assess potential vulnerability of special status species to the stressors chosen by the NRCA working group, using both park data and available literature. As a first step, we spent considerable effort

  1. Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations.

    PubMed

    Manoli, Gabriele; Domec, Jean-Christophe; Novick, Kimberly; Oishi, Andrew Christopher; Noormets, Asko; Marani, Marco; Katul, Gabriel

    2016-06-01

    Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation of young plantations replacing old forest in the southern United States will alter key aspects of the hydrologic cycle, including convective rainfall, which is the focus of the present work. Ecosystem fluxes of sensible (Hs) and latent heat (LE) and large-scale, slowly evolving free atmospheric temperature and water vapor content are known to be first-order controls on the formation of convective clouds in the atmospheric boundary layer. These controlling processes are here described by a zero-order analytical model aimed at assessing how plantations of different ages may regulate the persistence and transition of the atmospheric system between cloudy and cloudless conditions. Using the analytical model together with field observations, the roles of ecosystem Hs and LE on convective cloud formation are explored relative to the entrainment of heat and moisture from the free atmosphere. Our results demonstrate that cloudy-cloudless regimes at the land surface are regulated by a nonlinear relation between the Bowen ratio Bo=Hs/LE and root-zone soil water content, suggesting that young/mature pines ecosystems have the ability to recirculate available water (through rainfall predisposition mechanisms). Such nonlinearity was not detected in a much older pine stand, suggesting a higher tolerance to drought but a limited control on boundary layer dynamics. These results enable the generation of hypotheses about the impacts on convective cloud formation driven by afforestation/deforestation and groundwater depletion projected to increase following increased human population in the

  2. Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations.

    PubMed

    Manoli, Gabriele; Domec, Jean-Christophe; Novick, Kimberly; Oishi, Andrew Christopher; Noormets, Asko; Marani, Marco; Katul, Gabriel

    2016-06-01

    Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation of young plantations replacing old forest in the southern United States will alter key aspects of the hydrologic cycle, including convective rainfall, which is the focus of the present work. Ecosystem fluxes of sensible (Hs) and latent heat (LE) and large-scale, slowly evolving free atmospheric temperature and water vapor content are known to be first-order controls on the formation of convective clouds in the atmospheric boundary layer. These controlling processes are here described by a zero-order analytical model aimed at assessing how plantations of different ages may regulate the persistence and transition of the atmospheric system between cloudy and cloudless conditions. Using the analytical model together with field observations, the roles of ecosystem Hs and LE on convective cloud formation are explored relative to the entrainment of heat and moisture from the free atmosphere. Our results demonstrate that cloudy-cloudless regimes at the land surface are regulated by a nonlinear relation between the Bowen ratio Bo=Hs/LE and root-zone soil water content, suggesting that young/mature pines ecosystems have the ability to recirculate available water (through rainfall predisposition mechanisms). Such nonlinearity was not detected in a much older pine stand, suggesting a higher tolerance to drought but a limited control on boundary layer dynamics. These results enable the generation of hypotheses about the impacts on convective cloud formation driven by afforestation/deforestation and groundwater depletion projected to increase following increased human population in the

  3. Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants

    PubMed Central

    Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A. M.; Voesenek, Laurentius A. C. J.; Pierik, Ronald

    2015-01-01

    Background and Aims Volatile organic compounds (VOCs) play various roles in plant–plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar ‘Alva’ cause changes in biomass allocation in plants of the cultivar ‘Kara’. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant–plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant–plant signalling between ‘Alva’ and ‘Kara’. Methods The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by ‘Alva’ under control and far-red light-enriched conditions were analysed using gas chromatography–mass spectrometry (GC-MS). ‘Kara’ plants were exposed to the VOC blend emitted by the ‘Alva’ plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for ‘Kara’ plants exposed to ‘Alva’ VOCs, and also for ‘Alva’ plants exposed to either control or far-red-enriched light treatments. Key Results Total VOC emissions by ‘Alva’ were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by ‘Alva’ plants exposed to low R:FR was found to affect carbon allocation in receiver plants of ‘Kara’. Conclusions The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions

  4. Communities of different plant diversity respond similarly to drought stress: experimental evidence from field non-weeded and greenhouse conditions

    NASA Astrophysics Data System (ADS)

    Lanta, Vojtěch; Doležal, Jiří; Zemková, Lenka; Lepš, Jan

    2012-06-01

    Accelerating rate of species loss has prompted researchers to study the role of species diversity in processes that control ecosystem functioning. Although negative impact of species loss has been documented, the evidence concerning its impact on ecosystem stability is still limited. Here, we studied the effects of declining species and functional diversity on plant community responses to drought in the field (open to weed colonization) and greenhouse conditions. Both species and functional diversity positively affected the average yields of field communities. However, this pattern was similar in both drought-stressed and control plots. No effect of diversity on community resistance, biomass recovery after drought and resilience was found because drought reduced biomass production similarly at each level of diversity by approximately 30 %. The use of dissimilarity (characterized by Euclidean distance) revealed higher variation under changing environments (drought-stressed vs. control) in more diverse communities compared to less species-rich assemblages. In the greenhouse experiment, the effect of species diversity affected community resistance, indicating that more diverse communities suffered more from drought than species-poor ones. We conclude that our study did not support the insurance hypothesis (stability properties of a community should increase with species richness) because species diversity had an equivocal effect on ecosystem resistance and resilience in an environment held under non-weeded practice, regardless of the positive relationship between sown species diversity and community biomass production. More species-rich communities were less resistant against drought-stressed conditions than species-poor ones grown in greenhouse conditions.

  5. Fine-scale spatial variation in plant species richness and its relationship to environmental conditions in coastal marshlands

    USGS Publications Warehouse

    Mancera, J.E.; Meche, G.C.; Cardona-Olarte, P.P.; Castaneda-Moya, E.; Chiasson, R.L.; Geddes, N.A.; Schile, L.M.; Wang, H.G.; Guntenspergen, G.R.; Grace, J.B.

    2005-01-01

    Previous studies have shown that variations in environmental conditions play a major role in explaining variations in plant species richness at community and landscape scales. In this study, we considered the degree to which fine-scale spatial variations in richness could be related to fine-scale variations in abiotic and biotic factors. To examine spatial variation in richness, grids of 1 m(2) plots were laid out at five sites within a coastal riverine wetland landscape. At each site, a 5 x 7 array of plots was established adjacent to the river's edge with plots one meter apart. In addition to the estimation of species richness, environmental measurements included sediment salinity, plot microelevation, percent of plot recently disturbed, and estimated community biomass. Our analysis strategy was to combine the use of structural equation modeling (path modeling) with an assessment of spatial association. Mantel's tests revealed significant spatial autocorrelation in species richness at four of the five sites sampled, indicating that richness in a plot correlated with the richness of nearby plots. We subsequently considered the degree to which spatial autocorrelations in richness could be explained by spatial autocorrelations in environmental conditions. Once data were corrected for environmental correlations, spatial autocorrelation in residual species richness could not be detected at any site. Based on these results, we conclude that in this coastal wetland, there appears to be a fine-scale mapping of diversity to microgradients in environmental conditions.

  6. Characterization, Leaching, and Filtration Testing for Tributyl Phosphate (TBP, Group 7) Actual Waste Sample Composites

    SciTech Connect

    Edwards, Matthew K.; Billing, Justin M.; Blanchard, David L.; Buck, Edgar C.; Casella, Amanda J.; Casella, Andrew M.; Crum, J. V.; Daniel, Richard C.; Draper, Kathryn E.; Fiskum, Sandra K.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Snow, Lanee A.; Swoboda, Robert G.

    2009-03-09

    .A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. The tributyl phosphate sludge (TBP, Group 7) is the subject of this report. The Group 7 waste was anticipated to be high in phosphorus as well as aluminum in the form of gibbsite. Both are believed to exist in sufficient quantities in the Group 7 waste to address leaching behavior. Thus, the focus of the Group 7 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467.

  7. Application of Condition-Based Monitoring Techniques for Remote Monitoring of a Simulated Gas Centrifuge Enrichment Plant

    SciTech Connect

    Hooper, David A; Henkel, James J; Whitaker, Michael

    2012-01-01

    This paper presents research into the adaptation of monitoring techniques from maintainability and reliability (M&R) engineering for remote unattended monitoring of gas centrifuge enrichment plants (GCEPs) for international safeguards. Two categories of techniques are discussed: the sequential probability ratio test (SPRT) for diagnostic monitoring, and sequential Monte Carlo (SMC or, more commonly, particle filtering ) for prognostic monitoring. Development and testing of the application of condition-based monitoring (CBM) techniques was performed on the Oak Ridge Mock Feed and Withdrawal (F&W) facility as a proof of principle. CBM techniques have been extensively developed for M&R assessment of physical processes, such as manufacturing and power plants. These techniques are normally used to locate and diagnose the effects of mechanical degradation of equipment to aid in planning of maintenance and repair cycles. In a safeguards environment, however, the goal is not to identify mechanical deterioration, but to detect and diagnose (and potentially predict) attempts to circumvent normal, declared facility operations, such as through protracted diversion of enriched material. The CBM techniques are first explained from the traditional perspective of maintenance and reliability engineering. The adaptation of CBM techniques to inspector monitoring is then discussed, focusing on the unique challenges of decision-based effects rather than equipment degradation effects. These techniques are then applied to the Oak Ridge Mock F&W facility a water-based physical simulation of a material feed and withdrawal process used at enrichment plants that is used to develop and test online monitoring techniques for fully information-driven safeguards of GCEPs. Advantages and limitations of the CBM approach to online monitoring are discussed, as well as the potential challenges of adapting CBM concepts to safeguards applications.

  8. Steviol glycosides targeted analysis in leaves of Stevia rebaudiana (Bertoni) from plants cultivated under chilling stress conditions.

    PubMed

    Soufi, Sihem; D'Urso, Gilda; Pizza, Cosimo; Rezgui, Salah; Bettaieb, Taoufik; Montoro, Paola

    2016-01-01

    Stevia rebaudiana is an important agricultural crop for the production of a high-potency natural sweetener, sensitive to low temperature during the developmental stage. Stimulation of chilling stress with a pre-treatment with endogenous signalling components and in particular with salicylic acid (SA), hydrogen peroxide (H2O2), 6-benzylaminopurine (BAP) and calcium chloride (CaCl2) could induce tolerance to chilling and could constitute a suitable way to maintain quality and quantity of steviol glycosides under controlled artificial environment. In the present work the effects of different putative signalling molecules on the morpho-physiological parameters were evaluated, and a specific method for the quali-quantitative analysis of steviol glycosides in S. rebaudiana plants cultivated under controlled conditions was developed, by using LC-ESI-FT (Orbitrap) MS, LC-ESI-QqQ-MS/MS and multivariate data analysis. This approach underlined that the pre-treatment has influence on the production of secondary metabolites. In particular Stevia plants characterised by higher contents of rebaudioside A and stevioside, were identified. PMID:26213012

  9. Plant response to Na/sup +/, K/sup +/ and K/sup +//Na/sup +/ ratios under saline conditions

    SciTech Connect

    Devitt, D.A.

    1983-01-01

    This research was undertaken to more clearly determine plant response to saline-sodic waters. In the first experiment, the response of wheat and sorghum to different K/sup +//Na/sup +/ ratios at different osmotic potentials was investigated. The plants were grown in outdoor solution culture tanks containing polyethylene glycol and/or NaCl as osmoticum with 1/2 strength Hoagland as the base nutrient solution. The mass of the root system for both wheat and sorghum was determined primarily by the osmotic potential. However, root elongation was controlled primarily by the Na/sup +/ concentration. Sorghum root elongation rates decreased with increasing Na/sup +/ while those for wheat increased. Sodium was not translocated out of the sorghum root system until a critical Na/sup +/ root saturation level of .6 moles/kg was obtained. The second experiment was designed to investigate the water, nutrient and growth responses of the second crop of wheat in a wheat-sorghum-wheat rotation to zonal saline-sodic conditions.

  10. Steviol glycosides targeted analysis in leaves of Stevia rebaudiana (Bertoni) from plants cultivated under chilling stress conditions.

    PubMed

    Soufi, Sihem; D'Urso, Gilda; Pizza, Cosimo; Rezgui, Salah; Bettaieb, Taoufik; Montoro, Paola

    2016-01-01

    Stevia rebaudiana is an important agricultural crop for the production of a high-potency natural sweetener, sensitive to low temperature during the developmental stage. Stimulation of chilling stress with a pre-treatment with endogenous signalling components and in particular with salicylic acid (SA), hydrogen peroxide (H2O2), 6-benzylaminopurine (BAP) and calcium chloride (CaCl2) could induce tolerance to chilling and could constitute a suitable way to maintain quality and quantity of steviol glycosides under controlled artificial environment. In the present work the effects of different putative signalling molecules on the morpho-physiological parameters were evaluated, and a specific method for the quali-quantitative analysis of steviol glycosides in S. rebaudiana plants cultivated under controlled conditions was developed, by using LC-ESI-FT (Orbitrap) MS, LC-ESI-QqQ-MS/MS and multivariate data analysis. This approach underlined that the pre-treatment has influence on the production of secondary metabolites. In particular Stevia plants characterised by higher contents of rebaudioside A and stevioside, were identified.

  11. Arbuscular mycorrhizal fungi and plant growth-promoting pseudomonads increases anthocyanin concentration in strawberry fruits (Fragaria x ananassa var. Selva) in conditions of reduced fertilization.

    PubMed

    Lingua, Guido; Bona, Elisa; Manassero, Paola; Marsano, Francesco; Todeschini, Valeria; Cantamessa, Simone; Copetta, Andrea; D'Agostino, Giovanni; Gamalero, Elisa; Berta, Graziella

    2013-08-06

    Anthocyanins are a group of common phenolic compounds in plants. They are mainly detected in flowers and fruits, are believed to play different important roles such as in the attraction of animals and seed dispersal, and also in the increase of the antioxidant response in tissues directly or indirectly affected by biotic or abiotic stress factors. As a major group of secondary metabolites in plants commonly consumed as food, they are of importance in both the food industry and human nutrition. It is known that arbuscular mycorrhizal (AM) fungi can influence the plant secondary metabolic pathways such as the synthesis of essential oils in aromatic plants, of secondary metabolites in roots, and increase flavonoid concentration. Plant Growth-Promoting Bacteria (PGPB) are able to increase plant growth, improving plant nutrition and supporting plant development under natural or stressed conditions. Various studies confirmed that a number of bacterial species living on and inside the root system are beneficial for plant growth, yield and crop quality. In this work it is shown that inoculation with AM fungi and/or with selected and tested Pseudomonas strains, under conditions of reduced fertilization, increases anthocyanin concentration in the fruits of strawberry.

  12. Arbuscular mycorrhizal fungi and plant growth-promoting pseudomonads increases anthocyanin concentration in strawberry fruits (Fragaria x ananassa var. Selva) in conditions of reduced fertilization.

    PubMed

    Lingua, Guido; Bona, Elisa; Manassero, Paola; Marsano, Francesco; Todeschini, Valeria; Cantamessa, Simone; Copetta, Andrea; D'Agostino, Giovanni; Gamalero, Elisa; Berta, Graziella

    2013-01-01

    Anthocyanins are a group of common phenolic compounds in plants. They are mainly detected in flowers and fruits, are believed to play different important roles such as in the attraction of animals and seed dispersal, and also in the increase of the antioxidant response in tissues directly or indirectly affected by biotic or abiotic stress factors. As a major group of secondary metabolites in plants commonly consumed as food, they are of importance in both the food industry and human nutrition. It is known that arbuscular mycorrhizal (AM) fungi can influence the plant secondary metabolic pathways such as the synthesis of essential oils in aromatic plants, of secondary metabolites in roots, and increase flavonoid concentration. Plant Growth-Promoting Bacteria (PGPB) are able to increase plant growth, improving plant nutrition and supporting plant development under natural or stressed conditions. Various studies confirmed that a number of bacterial species living on and inside the root system are beneficial for plant growth, yield and crop quality. In this work it is shown that inoculation with AM fungi and/or with selected and tested Pseudomonas strains, under conditions of reduced fertilization, increases anthocyanin concentration in the fruits of strawberry. PMID:23924942

  13. Arbuscular Mycorrhizal Fungi and Plant Growth-Promoting Pseudomonads Increases Anthocyanin Concentration in Strawberry Fruits (Fragaria x ananassa var. Selva) in Conditions of Reduced Fertilization

    PubMed Central

    Lingua, Guido; Bona, Elisa; Manassero, Paola; Marsano, Francesco; Todeschini, Valeria; Cantamessa, Simone; Copetta, Andrea; D’Agostino, Giovanni; Gamalero, Elisa; Berta, Graziella

    2013-01-01

    Anthocyanins are a group of common phenolic compounds in plants. They are mainly detected in flowers and fruits, are believed to play different important roles such as in the attraction of animals and seed dispersal, and also in the increase of the antioxidant response in tissues directly or indirectly affected by biotic or abiotic stress factors. As a major group of secondary metabolites in plants commonly consumed as food, they are of importance in both the food industry and human nutrition. It is known that arbuscular mycorrhizal (AM) fungi can influence the plant secondary metabolic pathways such as the synthesis of essential oils in aromatic plants, of secondary metabolites in roots, and increase flavonoid concentration. Plant Growth-Promoting Bacteria (PGPB) are able to increase plant growth, improving plant nutrition and supporting plant development under natural or stressed conditions. Various studies confirmed that a number of bacterial species living on and inside the root system are beneficial for plant growth, yield and crop quality. In this work it is shown that inoculation with AM fungi and/or with selected and tested Pseudomonas strains, under conditions of reduced fertilization, increases anthocyanin concentration in the fruits of strawberry. PMID:23924942

  14. Effect of planting date and spacing on growth and yield of fennel (Foeniculum vulgare Mill.) under irrigated conditions.

    PubMed

    Al-Dalain, Saddam Aref; Abdel-Ghani, Adel H; Al-Dala'een, Jawad A; Thalaen, Haditha A

    2012-12-01

    Fennel (Foeniculum vulgare Mill.) plant is a medicinal aromatic herb and belongs to Apiaceae family. It has a rich nutritional value and has many medicinal usages. Very limited information is available in the literature about fennel cultivation and production practices. Therefore, this study was carried out to evaluate the effect of planting date and plant spacing and their interactive effects on yield, yield components and growth of Fennel under irrigation. Three planting dates (Oct. 1st, Nov. 1st and Dec. 1st) and four plant spacings (10, 20, 30 and 40 cm with constant row width, 60 cm) were used. Fruit yield was significantly (p<0.05) influenced by plant spacing and planting date and their interaction. Early planting significantly increased the fruit yield combined with higher number of branches per plant, number of umbrella per plant, number of fruit per plant and plant height. The percentage of increases in Oct. 1st were 34.4 and 32.2% in fruit and biological yield respectively compared with Dec. 1st. Harvest index and thousand fruit weight was not significantly affected by planting date. Increase plant spacing to 30 cm led to more than 15% increase in fruit and biological yield. The early planting date with 30 cm plant spacing resulted in higher fruit (4136 kg ha(-1)) and biological yield (10,114 kg ha(-1)).

  15. Spectrophotometric analysis of tomato plants produced from seeds exposed under space flight conditions for a long time

    NASA Astrophysics Data System (ADS)

    Nechitailo, Galina S.; Yurov, S.; Cojocaru, A.; Revin, A.

    The analysis of the lycopene and other carotenoids in tomatoes produced from seeds exposed under space flight conditions at the orbital station MIR for six years is presented in this work. Our previous experiments with tomato plants showed the germination of seeds to be 32%Genetic investigations revealed 18%in the experiment and 8%experiments were conducted to study the capacity of various stimulating factors to increase germination of seeds exposed for a long time to the action of space flight factors. An increase of 20%achieved but at the same time mutants having no analogues in the control variants were detected. For the present investigations of the third generation of plants produced from seeds stored for a long time under space flight conditions 80 tomatoes from forty plants were selected. The concentration of lycopene in the experimental specimens was 2.5-3 times higher than in the control variants. The spectrophotometric analysis of ripe tomatoes revealed typical three-peaked carotenoid spectra with a high maximum of lycopene (a medium maximum at 474 nm), a moderate maximum of its predecessor, phytoin, (a medium maximum at 267 nm) and a low maximum of carotenes. In green tomatoes, on the contrary, a high maximum of phytoin, a moderate maximum of lycopene and a low maximum of carotenes were observed. The results of the spectral analysis point to the retardation of biosynthesis of carotenes while the production of lycopene is increased and to the synthesis of lycopene from phytoin. Electric conduction of tomato juice in the experimental samples is increased thus suggesting higher amounts of carotenoids, including lycopene and electrolytes. The higher is the value of electric conduction of a specimen, the higher are the spectral maxima of lycopene. The hydrogen ion exponent of the juice of ripe tomatoes increases due to which the efficiency of ATP biosynthesis in cell mitochondria is likely to increase, too. The results demonstrating an increase in the content

  16. Cadmium toxicity investigated at the physiological and biophysical levels under environmentally relevant conditions using the aquatic model plant Ceratophyllum demersum.

    PubMed

    Andresen, Elisa; Kappel, Sophie; Stärk, Hans-Joachim; Riegger, Ulrike; Borovec, Jakub; Mattusch, Jürgen; Heinz, Andrea; Schmelzer, Christian E H; Matoušková, Šárka; Dickinson, Bryan; Küpper, Hendrik

    2016-06-01

    Cadmium (Cd) is an important environmental pollutant and is poisonous to most organisms. We aimed to unravel the mechanisms of Cd toxicity in the model water plant Ceratophyllum demersum exposed to low (nM) concentrations of Cd as are present in nature. Experiments were conducted under environmentally relevant conditions, including nature-like light and temperature cycles, and a low biomass to water ratio. We measured chlorophyll (Chl) fluorescence kinetics, oxygen exchange, the concentrations of reactive oxygen species and pigments, metal binding to proteins, and the accumulation of starch and metals. The inhibition threshold concentration for most parameters was 20 nM. Below this concentration, hardly any stress symptoms were observed. The first site of inhibition was photosynthetic light reactions (the maximal quantum yield of photosystem II (PSII) reaction centre measured as Fv /Fm , light-acclimated PSII activity ΦPSII , and total Chl). Trimers of the PSII light-harvesting complexes (LHCIIs) decreased more than LHC monomers and detection of Cd in the monomers suggested replacement of magnesium (Mg) by Cd in the Chl molecules. As a consequence of dysfunctional photosynthesis and energy dissipation, reactive oxygen species (superoxide and hydrogen peroxide) appeared. Cadmium had negative effects on macrophytes at much lower concentrations than reported previously, emphasizing the importance of studies applying environmentally relevant conditions. A chain of inhibition events could be established. PMID:26840406

  17. New insights into pioneer root xylem development: evidence obtained from Populus trichocarpa plants grown under field conditions

    PubMed Central

    Bagniewska-Zadworna, Agnieszka; Arasimowicz-Jelonek, Magdalena; Smoliński, Dariusz J.; Stelmasik, Agnieszka

    2014-01-01

    Background and Aims Effective programmed xylogenesis is critical to the structural framework of the plant root system and its central role in the acquisition and long-distance transport of water and nutrients. The process of xylem differentiation in pioneer roots under field conditions is poorly understood. In this study it is hypothesized that xylogenesis, an example of developmental programmed cell death (PCD), in the roots of woody plants demonstrates a clearly defined sequence of events resulting in cell death. A comprehensive analysis was therefore undertaken to identify the stages of xylogenesis in pioneer roots from procambial cells to fully functional vessels with lignified cell walls and secondary cell wall thickenings. Methods Xylem differentiation was monitored in the pioneer roots of Populus trichocarpa at the cytological level using rhizotrons under field conditions. Detection and localization of the signalling molecule nitric oxide (NO) and hydrogen peroxide (H2O2) was undertaken and a detailed examination of nuclear changes during xylogenesis was conducted. In addition, analyses of the expression of genes involved in secondary cell wall synthesis were performed in situ. Key Results The primary event in initially differentiating tracheary elements (TEs) was a burst of NO in thin-walled cells, followed by H2O2 synthesis and the appearance of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling)-positive nuclei. The first changes in nuclear structure were observed in the early stages of xylogenesis of pioneer roots, prior to lignification; however, the nucleus was detectable under transmission electron microscopy in differentiating cells until the stage at which vacuole integrity was maintained, indicating that their degradation was slow and prolonged. The subsequent sequence of events involved secondary cell wall formation and autophagy. Potential gene markers from the cinnamyl alcohol dehydrogenase (CAD) gene family that were

  18. Relationship of perceived and actual motor competence in children.

    PubMed

    Raudsepp, Lennart; Liblik, Raino

    2002-06-01

    The purpose of this study was to examine the relationship between children's actual and perceived motor competence. 280 children between the ages of 10 and 13 years individually completed the Children's Physical Self-perception Profile which assesses perceptions of sport competence, physical conditioning, strength, body attractiveness, and general physical self-worth. The internal reliabilities (a) of the subscales ranged from .75 to .82. After completing the profile, the subject's actual motor competence was measured using tests of aerobic fitness and functional strength. Body fatness (sum of five skinfolds) was measured as an objective measure of perceived body attractiveness. Analysis of variance showed that boys and girls differed in perceived competence and actual motor competence. The boys showed higher perceived competence on four scores, but there was no sex difference in perception of body attractiveness. Correlations and regression analysis showed that actual and perceived motor competence were significantly but only moderately (r =.25-.56) correlated. In addition, items of perceived physical competence and age accounted for 17% (sit-ups) to 25% (endurance shuttle run) of the variance in actual motor competence of the children. These findings showed that 10- to 13-yr-old children can only moderately assess personal motor competence. PMID:12186225

  19. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern

    USGS Publications Warehouse

    Huber, Ann; Das, Adrian; Wenk, Rebecca; Haultain, Sylvia

    2013-01-01

    Database (CNDDB 2010a). There are an additional 66 taxa not formally listed by CNDDB that are recognized as having special status because their distribution is restricted to the Sierra Nevada. Special status plants are distributed throughout the two parks and inhabit a wide range of environments along the length of the elevation gradient that characterizes these parks. Ideally, we would assess the condition (status and trends) of each of the taxa on the SEKI special status plant list, documenting current population sizes, demographic rates and demographic trends. We would also hope to quantify the effects of individual stressors on each species based on existing monitoring and research. However, no data are available for most of the species on the special status plant list. For those few species (12 herbaceous species and two tree species) for which we possess some change over time information, the data are not adequate to make a competent assessment. Note that we have not explored the tree demographic information in any detail, as is covered in the NRCA Intact Forest/Five Needle Pines and Sequoia chapters. In general, we are unable to present an ‗integrity‘ metric for special status species in the parks, since the data to quantify the condition of each species in such a manner is not available. In contrast, the park does possess substantial data describing biodiversity in the parks. Therefore, our analysis focuses on describing the distribution and rarity of special status plants within the parks, with a particular focus on assessing the spatial distribution of species richness. We hope that such information will prove useful to park managers in determining which areas in the parks merit the most attention (for example in developing monitoring protocols). We also assess potential vulnerability of special status species to the stressors chosen by the NRCA working group, using both park data and available literature. As a first step, we spent considerable effort

  20. Self-Actualization, Liberalism, and Humanistic Education.

    ERIC Educational Resources Information Center

    Porter, Charles Mack

    1979-01-01

    The relationship between personality factors and political orientation has long been of interest to psychologists. This study tests the hypothesis that there is no significant relationship between self-actualization and liberalism-conservatism. The hypothesis is supported. (Author)

  1. Uptake of cyantraniliprole into tomato fruit and foliage under hydroponic conditions: application to calibration of a plant/soil uptake model.

    PubMed

    Anderson, Jeffrey J; Bookhart, S Wingard; Clark, Jonathan M; Jernberg, Kathryn M; Kingston, Coleen K; Snyder, Nathan; Wallick, Kevin; Watson, Lawrence J

    2013-09-25

    Measured uptake of cyantraniliprole (3-bromo-1-(3-chloro-2-pyridinyl)-N-[4-cyano-2-methyl-6-[(methylamino)carbonyl]phenyl]-1H-pyrazole-5-carboxamide) into tomatoes following hydroponic exposure allowed calibration of a novel soil uptake model. The total mass of plant parts in treated plants was derived from the weights of successively harvested control plants (no cyantraniliprole provided) over 18 days following the first sampling of ripe tomatoes. Transpired water measured during plant growth was coupled with the calculated increase in plant mass to determine a transpiration coefficient constant (L/kg plant fresh weight) for use in the model. Cyantraniliprole concentrations in mature fruit, fresh foliage, and plant uptake solutions were used as the basis for a nonlinear least-squares optimization that consistently resolved to values that were empirically valid compared to metabolism studies in whole plants. This calibrated reference model adequately described uptake from soil pore water into plant fruit, and served as the basis for describing residues in fruit following commercial greenhouse growing conditions.

  2. Uptake of cyantraniliprole into tomato fruit and foliage under hydroponic conditions: application to calibration of a plant/soil uptake model.

    PubMed

    Anderson, Jeffrey J; Bookhart, S Wingard; Clark, Jonathan M; Jernberg, Kathryn M; Kingston, Coleen K; Snyder, Nathan; Wallick, Kevin; Watson, Lawrence J

    2013-09-25

    Measured uptake of cyantraniliprole (3-bromo-1-(3-chloro-2-pyridinyl)-N-[4-cyano-2-methyl-6-[(methylamino)carbonyl]phenyl]-1H-pyrazole-5-carboxamide) into tomatoes following hydroponic exposure allowed calibration of a novel soil uptake model. The total mass of plant parts in treated plants was derived from the weights of successively harvested control plants (no cyantraniliprole provided) over 18 days following the first sampling of ripe tomatoes. Transpired water measured during plant growth was coupled with the calculated increase in plant mass to determine a transpiration coefficient constant (L/kg plant fresh weight) for use in the model. Cyantraniliprole concentrations in mature fruit, fresh foliage, and plant uptake solutions were used as the basis for a nonlinear least-squares optimization that consistently resolved to values that were empirically valid compared to metabolism studies in whole plants. This calibrated reference model adequately described uptake from soil pore water into plant fruit, and served as the basis for describing residues in fruit following commercial greenhouse growing conditions. PMID:24000775

  3. Low-temperature conditioning of "seed" cloves enhances the expression of phenolic metabolism related genes and anthocyanin content in 'Coreano' garlic (Allium sativum) during plant development.

    PubMed

    Dufoo-Hurtado, Miguel D; Zavala-Gutiérrez, Karla G; Cao, Cong-Mei; Cisneros-Zevallos, Luis; Guevara-González, Ramón G; Torres-Pacheco, Irineo; Vázquez-Barrios, M Estela; Rivera-Pastrana, Dulce M; Mercado-Silva, Edmundo M

    2013-11-01

    Low-temperature conditioning of garlic "seed" cloves accelerated the development of the crop cycle, decreased plant growth, and increased the synthesis of phenolic compounds and anthocyanins in the outer scale leaves of the bulbs at harvest time, leading to 3-fold content increase compared with those conditioned at room temperature. Cold conditioning of "seed" cloves also altered the anthocyanin profile during bulb development and at harvest. Two new anthocyanins are reported for the first time in garlic. The high phenolics and anthocyanin contents in bulbs of plants generated from "seed" cloves conditioned at 5 °C for 5 weeks were preceded by overexpression of some putative genes of the phenolic metabolism [6-fold for phenylalanine ammonia lyase (PAL)] and anthocyanin synthesis [1-fold for UDP-sugar:flavonoid 3-O-glycosyltransferase (UFGT)] compared with those conditioned at room temperature.

  4. Fruit maturation, not deteriorating light conditions, is the primary cue of senescence in a spring ephemeral annual plant--Floerkea proserpinacoides (Limnanthaceae).

    PubMed

    Mokhtar, Ines Ben; Houle, Gilles

    2005-03-01

    In monocarpic plants, reproduction is closely associated with senescence, which is itself often correlated to specific environmental signals. Floerkea proserpinacoides (Limnanthaceae) is a spring ephemeral annual of the deciduous forests of eastern North America. The phenology of its growth and reproduction is considered to be a specific adaptation to the short period during which there is a high availability of resources (mostly light). Indeed, flowering starts 2-3 wk following seedling emergence soon after snowmelt and continues until tree canopy closure. However, fruit maturation is postponed for several weeks and is followed by the plant's death. The objective of this study is to determine if senescence in F. proserpinacoides is primarily cued by fruit maturation or deteriorating light conditions associated with tree canopy closure. Plants for which reproductive investment was manipulated by removing their carpels were grown either in full light or in the shade. Carpel-removal plants reached a higher biomass than control plants (46.0- 57.5% higher), especially in full light. However, longevity was greater in carpel-removal plants, particularly in the shade (25.3-37.8% greater). These results thus suggest that fruit maturation, not deteriorating light conditions associated with canopy closure, is the primary cue of plant senescence in F. proserpinacoides.

  5. Observed and simulated effect of plant physiology and structure on land surface energy fluxes and soil conditions

    NASA Astrophysics Data System (ADS)

    Lu, Yen-Sen; Rihani, Jehan; Langensiepen, Matthias; Simmer, Clemens

    2016-04-01

    The parameterization of stomatal conductance and leaf area index (LAI) in land surface models largely influence simulated terrestrial system states. While stomatal conductance mainly controls transpiration, latent heat flux, and root-water-uptake, LAI impacts additionally the radiative energy exchange. Thus both affect canopy evaporation and transpiration and land surface energy and water fluxes as a whole. Common parameterizations of stomatal conductance follow either semi-mechanistic forms based on photosynthesis (Ball-Berry Type (BB)) or forms which consider environmental factors such as impact of light, temperature, humidity and soil moisture (Jarvis-Stewart Type (JS)). Both approaches differ also in the interpretation of humidity effects and light-use efficiency. While soil moisture plays an important role for root-water-uptake there is no clear conclusion yet about how soil moisture interacts with stomata activity. Values for LAI can be obtained from field measurements, satellite estimates or modelling and are used as an essential model input. While field measurements are very time consuming and only represent single points, satellite estimates may have biases caused by variable albedo and sensor limitations. Representing LAI within land surface models requires complex schemes in order to represent all processes contributing to plant growth. We use the Terrestrial System Modelling Platform (TerrSysMP) over the Rur watershed in Germany for studying the influence of plant physiology and structure on the state of the terrestrial system. The Transregional Collaborative Research Center 32 (TR32) extensively monitors this catchment for almost a decade. The land surface (CLM3.5) and the subsurface (ParFlow) modules of TerrSysMP are conditioned based on satellite-retrieved land cover and the soil map from FAO and forced with a high-resolution reanalysis by DWD. For studying the effect of plant physiology, the Ball-Berry-Leuning, and Jarvis-Stewart stomatal

  6. Effects of meteorological conditions and plant growth stage on the accumulation of carvacrol and its precursors in Thymus pulegioides.

    PubMed

    Vaičiulytė, Vaida; Butkienė, Rita; Ložienė, Kristina

    2016-08-01

    The effects of meteorological conditions (temperature, rainfall, photosynthetically active solar radiation (PAR) and sunshine duration) and plant growth stages on the quantitative composition of a secondary metabolite - essential oil and its main compounds, in the carvacrol chemotype of Thymus pulegioides L. (Lamiaceae) cultivated in open ground were studied under the same micro-edaphoclimatic environmental conditions for six years. The essential oil was isolated by hydrodistillation, the analysis of monoterpenic phenol carvacrol and the biogenetic precursors (monoterpene hydrocarbons p-cymene and γ-terpinene) were carried out annually using GC-FID and GC-MS. In the carvacrol chemotype investigated in this study, the yield of essential oil varied from 0.72% to 0.98% (CV = 12%) at full flowering stage. Regression analysis showed a significant negative relationship between the amount of essential oil and both temperature and rainfall during T. pulegioides flowering (July) and the period from April (beginning of vegetation) to July, but a strong positive relationship with photosynthetically active solar radiation during April-July (beta = 0.658, p < 0.05). The percentage of carvacrol, p-cymene and γ-terpinene ranged between 16.88 and 29.29% (CV = 18%), 5.54-11.33% (CV = 23%) and 20.60-24.43% (CV = 6%) respectively. Regression analysis showed the significant positive relationship between the percentage of carvacrol and sunshine duration at the flowering stage (in July) (beta = 0.699, p < 0.05); while the negative relationship was established between the percentages of precursors of carvacrol and photosynthetically active solar radiation and sunshine duration. The accumulation of p-cymene, the percentage of which varied most strongly from all investigated chemical compounds, showed significant positive relationships with temperature and rainfall during the period April-July and temperature in July (beta = 0.617, beta = 0.439 and beta = 0

  7. Effects of meteorological conditions and plant growth stage on the accumulation of carvacrol and its precursors in Thymus pulegioides.

    PubMed

    Vaičiulytė, Vaida; Butkienė, Rita; Ložienė, Kristina

    2016-08-01

    The effects of meteorological conditions (temperature, rainfall, photosynthetically active solar radiation (PAR) and sunshine duration) and plant growth stages on the quantitative composition of a secondary metabolite - essential oil and its main compounds, in the carvacrol chemotype of Thymus pulegioides L. (Lamiaceae) cultivated in open ground were studied under the same micro-edaphoclimatic environmental conditions for six years. The essential oil was isolated by hydrodistillation, the analysis of monoterpenic phenol carvacrol and the biogenetic precursors (monoterpene hydrocarbons p-cymene and γ-terpinene) were carried out annually using GC-FID and GC-MS. In the carvacrol chemotype investigated in this study, the yield of essential oil varied from 0.72% to 0.98% (CV = 12%) at full flowering stage. Regression analysis showed a significant negative relationship between the amount of essential oil and both temperature and rainfall during T. pulegioides flowering (July) and the period from April (beginning of vegetation) to July, but a strong positive relationship with photosynthetically active solar radiation during April-July (beta = 0.658, p < 0.05). The percentage of carvacrol, p-cymene and γ-terpinene ranged between 16.88 and 29.29% (CV = 18%), 5.54-11.33% (CV = 23%) and 20.60-24.43% (CV = 6%) respectively. Regression analysis showed the significant positive relationship between the percentage of carvacrol and sunshine duration at the flowering stage (in July) (beta = 0.699, p < 0.05); while the negative relationship was established between the percentages of precursors of carvacrol and photosynthetically active solar radiation and sunshine duration. The accumulation of p-cymene, the percentage of which varied most strongly from all investigated chemical compounds, showed significant positive relationships with temperature and rainfall during the period April-July and temperature in July (beta = 0.617, beta = 0.439 and beta = 0

  8. Engineering Pseudomonas protegens Pf-5 for nitrogen fixation and its application to improve plant growth under nitrogen-deficient conditions.

    PubMed

    Setten, Lorena; Soto, Gabriela; Mozzicafreddo, Matteo; Fox, Ana Romina; Lisi, Christian; Cuccioloni, Massimiliano; Angeletti, Mauro; Pagano, Elba; Díaz-Paleo, Antonio; Ayub, Nicolás Daniel

    2013-01-01

    Nitrogen is the second most critical factor for crop production after water. In this study, the beneficial rhizobacterium Pseudomonas protegens Pf-5 was genetically modified to fix nitrogen using the genes encoding the nitrogenase of Pseudomonas stutzeri A1501 via the X940 cosmid. Pf-5 X940 was able to grow in L medium without nitrogen, displayed high nitrogenase activity and released significant quantities of ammonium to the medium. Pf-5 X940 also showed constitutive expression and enzymatic activity of nitrogenase in ammonium medium or in nitrogen-free medium, suggesting a constitutive nitrogen fixation. Similar to Pseudomonas protegens Pf-5, Pseudomonas putida, Pseudomonas veronii and Pseudomonas taetrolens but not Pseudomonas balearica and Pseudomonas stutzeri transformed with cosmid X940 showed constitutive nitrogenase activity and high ammonium production, suggesting that this phenotype depends on the genome context and that this technology to obtain nitrogen-fixing bacteria is not restricted to Pf-5. Interestingly, inoculation of Arabidopsis, alfalfa, tall fescue and maize with Pf-5 X940 increased the ammonium concentration in soil and plant productivity under nitrogen-deficient conditions. In conclusion, these results open the way to the production of effective recombinant inoculants for nitrogen fixation on a wide range of crops.

  9. Engineering Pseudomonas protegens Pf-5 for Nitrogen Fixation and its Application to Improve Plant Growth under Nitrogen-Deficient Conditions

    PubMed Central

    Setten, Lorena; Soto, Gabriela; Mozzicafreddo, Matteo; Fox, Ana Romina; Lisi, Christian; Cuccioloni, Massimiliano; Angeletti, Mauro; Pagano, Elba; Díaz-Paleo, Antonio; Ayub, Nicolás Daniel

    2013-01-01

    Nitrogen is the second most critical factor for crop production after water. In this study, the beneficial rhizobacterium Pseudomonas protegens Pf-5 was genetically modified to fix nitrogen using the genes encoding the nitrogenase of Pseudomonas stutzeri A1501 via the X940 cosmid. Pf-5 X940 was able to grow in L medium without nitrogen, displayed high nitrogenase activity and released significant quantities of ammonium to the medium. Pf-5 X940 also showed constitutive expression and enzymatic activity of nitrogenase in ammonium medium or in nitrogen-free medium, suggesting a constitutive nitrogen fixation. Similar to Pseudomonas protegens Pf-5, Pseudomonas putida, Pseudomonas veronii and Pseudomonas taetrolens but not Pseudomonas balearica and Pseudomonas stutzeri transformed with cosmid X940 showed constitutive nitrogenase activity and high ammonium production, suggesting that this phenotype depends on the genome context and that this technology to obtain nitrogen-fixing bacteria is not restricted to Pf-5. Interestingly, inoculation of Arabidopsis, alfalfa, tall fescue and maize with Pf-5 X940 increased the ammonium concentration in soil and plant productivity under nitrogen-deficient conditions. In conclusion, these results open the way to the production of effective recombinant inoculants for nitrogen fixation on a wide range of crops. PMID:23675499

  10. Increased belowground C release during initial plant development of Populus deltoides x nigra grown under light and C reserve limited conditions

    NASA Astrophysics Data System (ADS)

    Studer, Mirjam S.; Siegwolf, Rolf T. W.; Schmidt, Michael W. I.; Abiven, Samuel

    2014-05-01

    Plants might be a key factor for the long-term stabilisation of carbon (C) in the soil, e.g. through enhanced physical protection of root-derived C against microbial decomposition in soil aggregates. On the other hand C released by the plants into the soil might promote the decomposition of native soil organic matter (SOM) through the stimulation of microbial activity. We measured the C budget of developing plant-soil systems (Populus deltoides x nigra, Cambisol soil) in the laboratory under controlled environmental conditions. In order to distinguish plant-derived from native C in the SOM and the soil CO2 efflux, we labelled the poplar shoots continuously with 13C-CO2 from first emergence of leaves (sprouting from stem cuttings). Throughout the experiment the CO2 fluxes (photosynthetic assimilation, dark respiratory loss, soil CO2 efflux) were measured frequently (every 30 min) and the 13C was traced in the soil CO2 efflux (1-2 times a week). After 10 weeks the plant-soil systems were destructively harvested and the distribution of the 13C distribution was analysed. The plants developed slowly (compared to previous experiments), most likely due to limitation in C reserves (long term cutting storage) and C supply (low light intensities). The amount of 13C recovered in the roots, microbial biomass and soil CO2 efflux was directly correlated with the leaf area of the different plant individuals. After 3-4 weeks of plant development we observed a high peak in the total soil CO2 efflux. During this time the relative belowground C release was increased massively over the basal rate of 17 % of net C assimilated, whereby the variability between the plant individuals was large. The smallest plants, i.e. the plants that were most resource limited, obtained the highest belowground C release accounting at the peak time for up to 57 % of net assimilated C. We hypothesize that the plants released specific compounds, which either directly (enzymatically) or indirectly (priming

  11. Plant virus emergence and evolution: origins, new encounter scenarios, factors driving emergence, effects of changing world conditions, and prospects for control.

    PubMed

    Jones, Roger A C

    2009-05-01

    This review focuses on virus-plant pathosystems at the interface between managed and natural vegetation, and describes how rapid expansion in human activity and climate change are likely to impact on plants, vectors and viruses causing increasing instability. It starts by considering virus invasion of cultivated plants from their wild ancestors in the centres of plant domestication in different parts of the world and subsequent long distance movement away from these centres to other continents. It then describes the diverse virus-plant pathosystem scenarios possible at the interface between managed and natural vegetation and gives examples that illustrate situations where indigenous viruses emerge to damage introduced cultivated plants and newly introduced viruses become potential threats to biodiversity. These examples demonstrate how human activities increasingly facilitate damaging new encounters between plants and viruses worldwide. The likely effects of climate change on virus emergence are emphasised, and the major factors driving virus emergence, evolution and greater epidemic severity at the interface are analysed and explained. Finally, the kinds of challenges posed by rapidly changing world conditions to achieving effective control of epidemics of emerging plant viruses, and the approaches needed to address them, are described. PMID:19159652

  12. Remotion of organic compounds of actual industrial effluents by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Sampa, M. H. O.; Duarte, C. L.; Rela, P. R.; Somessari, E. S. R.; Silveira, C. G.; Azevedo, A. L.

    1998-06-01

    Organic compounds has been a great problem of environmental pollution, the traditional methods are not effecient on removing these compounds and most of them are deposited to ambient and stay there for long time causing problems to the environment. Ionizing radiation has been used with success to destroy organic molecules. Actual industrial effluents were irradiated using IPEN's electron beam wastewater pilot plant to study organic compounds degradation. The samples were irradiated with and without air mixture by different doses. Irradiation treatment efficiency was evaluated by the Cromatography Gas Analyses of the samples before and after irradiation. The studied organic compounds were: phenol, chloroform, tetrachloroethylene (PCE), carbon tetrachloride, trichloroethylene (TCE), 1,1-dichloroethane, dichloromethane, benzene, toluene and xilene. A degradation superior to 80% was achieved for the majority of the compounds with air addition and 2kGy delivered dose condition. For the samples that were irradiated without air addition the degradation was higher.

  13. Nematode community shifts in response to experimental warming and canopy conditions are associated with plant community changes in the temperate-boreal forest ecotone.

    PubMed

    Thakur, Madhav Prakash; Reich, Peter B; Fisichelli, Nicholas A; Stefanski, Artur; Cesarz, Simone; Dobies, Tomasz; Rich, Roy L; Hobbie, Sarah E; Eisenhauer, Nico

    2014-06-01

    Global climate warming is one of the key forces driving plant community shifts, such as range shifts of temperate species into boreal forests. As plant community shifts are slow to observe, ecotones, boundaries between two ecosystems, are target areas for providing early evidence of ecological responses to warming. The role of soil fauna is poorly explored in ecotones, although their positive and negative effects on plant species can influence plant community structure. We studied nematode communities in response to experimental warming (ambient, +1.7, +3.4 °C) in soils of closed and open canopy forest in the temperate-boreal ecotone of Minnesota, USA and calculated various established nematode indices. We estimated species-specific coverage of understory herbaceous and shrub plant species from the same experimental plots and tested if changes in the nematode community are associated with plant cover and composition. Individual nematode trophic groups did not differ among warming treatments, but the ratio between microbial-feeding and plant-feeding nematodes increased significantly and consistently with warming in both closed and open canopy areas and at both experimental field sites. The increase in this ratio was positively correlated with total cover of understory plant species, perhaps due to increased predation pressure on soil microorganisms causing higher nutrient availability for plants. Multivariate analyses revealed that temperature treatment, canopy conditions and nematode density consistently shaped understory plant communities across experimental sites. Our findings suggest that warming-induced changes in nematode community structure are associated with shifts in plant community composition and productivity in the temperate-boreal forest ecotones.

  14. Effects of mineral nutrition conditions on heat tolerance of chufa (Сyperus esculentus L.) plant communities to super optimal air temperatures in the BTLSS

    NASA Astrophysics Data System (ADS)

    Shklavtsova, E. S.; Ushakova, S. A.; Shikhov, V. N.; Anishchenko, O. V.

    2014-09-01

    The use of mineralized human wastes as a basis for nutrient solutions will increase the degree of material closure of bio-technical human life support systems. As stress tolerance of plants is determined, among other factors, by the conditions under which they have been grown before exposure to a stressor, the purpose of the study is to investigate the level of tolerance of chufa (Cyperus esculentus L.) plant communities grown in solutions based on mineralized human wastes to a damaging air temperature, 45 °C. Experiments were performed with 30-day-old chufa plant communities grown hydroponically, on expanded clay aggregate, under artificial light, at 690 μmol m-2 s-1 PAR and at a temperature of 25 °C. Plants were grown in Knop’s solution and solutions based on human wastes mineralized according to Yu.A. Kudenko’s method, which contained nitrogen either as ammonium and urea or as nitrates. The heat shock treatment lasted 20 h at 690 and 1150 μmol m-2 s-1 PAR. Chufa heat tolerance was evaluated based on parameters of CO2 gas exchange, the state of its photosynthetic apparatus (PSA), and intensity of peroxidation of leaf lipids. Chufa plants grown in the solutions based on mineralized human wastes that contained ammonium and urea had lower heat tolerance than plants grown in standard mineral solutions. Heat tolerance of the plants grown in the solutions based on mineralized human wastes that mainly contained nitrate nitrogen was insignificantly different from the heat tolerance of the plants grown in standard mineral solutions. A PAR intensity increase from 690 μmol m-2 s-1 to 1150 μmol m-2 s-1 enhanced heat tolerance of chufa plant communities, irrespective of the conditions of mineral nutrition under which they had been grown.

  15. Realizing actual feedback control of complex network

    NASA Astrophysics Data System (ADS)

    Tu, Chengyi; Cheng, Yuhua

    2014-06-01

    In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.

  16. Fate of NDMA precursors through an MBR-NF pilot plant for urban wastewater reclamation and the effect of changing aeration conditions.

    PubMed

    Mamo, Julian; Insa, Sara; Monclús, Hèctor; Rodríguez-Roda, Ignasi; Comas, Joaquim; Barceló, Damià; Farré, Maria José

    2016-10-01

    The removal of N-nitrosodimethylamine (NDMA) formation potential through a membrane bioreactor (MBR) coupled to a nanofiltration (NF) pilot plant that treats urban wastewater is investigated. The results are compared to the fate of the individual NDMA precursors detected: azithromycin, citalopram, erythromycin, clarithromycin, ranitidine, venlafaxine and its metabolite o-desmethylvenlafaxine. Specifically, the effect of dissolved oxygen in the aerobic chamber of the MBR pilot plant on the removal of NDMA formation potential (FP) and individual precursors is studied. During normal aerobic operation, implying a fully nitrifying system, the MBR was able to reduce NDMA precursors above 94%, however this removal percentage was reduced to values as low as 72% when changing the conditions to minimize nitrification. Removal decreased also for azithromycin (68-59%), citalopram (31-17%), venlafaxine (35-15%) and erythromycin (61-16%) on average during nitrifying versus non-nitrifying conditions. The removal of clarithromycin, o-desmethylvenlafaxine and ranitidine could not be correlated with the nitrification inhibition, as it varied greatly during the experiment time. The MBR pilot plant is coupled to a nanofiltration (NF) system and the results on the rejection of both, NDMA FP and individual precursors, through this system was above 90%. Finally, results obtained for the MBR pilot plant are compared to the percentage of removal by a conventional full scale biological wastewater treatment plant (WWTP) fed with the same influent. During aerobic operation, the removal of NDMA FP by the MBR pilot plant was similar to the full scale WWTP.

  17. Overexpression of Arabidopsis NLP7 improves plant growth under both nitrogen-limiting and -sufficient conditions by enhancing nitrogen and carbon assimilation

    PubMed Central

    Yu, Lin-Hui; Wu, Jie; Tang, Hui; Yuan, Yang; Wang, Shi-Mei; Wang, Yu-Ping; Zhu, Qi-Sheng; Li, Shi-Gui; Xiang, Cheng-Bin

    2016-01-01

    Nitrogen is essential for plant survival and growth. Excessive application of nitrogenous fertilizer has generated serious environment pollution and increased production cost in agriculture. To deal with this problem, tremendous efforts have been invested worldwide to increase the nitrogen use ability of crops. However, only limited success has been achieved to date. Here we report that NLP7 (NIN-LIKE PROTEIN 7) is a potential candidate to improve plant nitrogen use ability. When overexpressed in Arabidopsis, NLP7 increases plant biomass under both nitrogen-poor and -rich conditions with better-developed root system and reduced shoot/root ratio. NLP7–overexpressing plants show a significant increase in key nitrogen metabolites, nitrogen uptake, total nitrogen content, and expression levels of genes involved in nitrogen assimilation and signalling. More importantly, overexpression of NLP7 also enhances photosynthesis rate and carbon assimilation, whereas knockout of NLP7 impaired both nitrogen and carbon assimilation. In addition, NLP7 improves plant growth and nitrogen use in transgenic tobacco (Nicotiana tabacum). Our results demonstrate that NLP7 significantly improves plant growth under both nitrogen-poor and -rich conditions by coordinately enhancing nitrogen and carbon assimilation and sheds light on crop improvement. PMID:27293103

  18. Overexpression of Arabidopsis NLP7 improves plant growth under both nitrogen-limiting and -sufficient conditions by enhancing nitrogen and carbon assimilation.

    PubMed

    Yu, Lin-Hui; Wu, Jie; Tang, Hui; Yuan, Yang; Wang, Shi-Mei; Wang, Yu-Ping; Zhu, Qi-Sheng; Li, Shi-Gui; Xiang, Cheng-Bin

    2016-01-01

    Nitrogen is essential for plant survival and growth. Excessive application of nitrogenous fertilizer has generated serious environment pollution and increased production cost in agriculture. To deal with this problem, tremendous efforts have been invested worldwide to increase the nitrogen use ability of crops. However, only limited success has been achieved to date. Here we report that NLP7 (NIN-LIKE PROTEIN 7) is a potential candidate to improve plant nitrogen use ability. When overexpressed in Arabidopsis, NLP7 increases plant biomass under both nitrogen-poor and -rich conditions with better-developed root system and reduced shoot/root ratio. NLP7-overexpressing plants show a significant increase in key nitrogen metabolites, nitrogen uptake, total nitrogen content, and expression levels of genes involved in nitrogen assimilation and signalling. More importantly, overexpression of NLP7 also enhances photosynthesis rate and carbon assimilation, whereas knockout of NLP7 impaired both nitrogen and carbon assimilation. In addition, NLP7 improves plant growth and nitrogen use in transgenic tobacco (Nicotiana tabacum). Our results demonstrate that NLP7 significantly improves plant growth under both nitrogen-poor and -rich conditions by coordinately enhancing nitrogen and carbon assimilation and sheds light on crop improvement. PMID:27293103

  19. Fate of NDMA precursors through an MBR-NF pilot plant for urban wastewater reclamation and the effect of changing aeration conditions.

    PubMed

    Mamo, Julian; Insa, Sara; Monclús, Hèctor; Rodríguez-Roda, Ignasi; Comas, Joaquim; Barceló, Damià; Farré, Maria José

    2016-10-01

    The removal of N-nitrosodimethylamine (NDMA) formation potential through a membrane bioreactor (MBR) coupled to a nanofiltration (NF) pilot plant that treats urban wastewater is investigated. The results are compared to the fate of the individual NDMA precursors detected: azithromycin, citalopram, erythromycin, clarithromycin, ranitidine, venlafaxine and its metabolite o-desmethylvenlafaxine. Specifically, the effect of dissolved oxygen in the aerobic chamber of the MBR pilot plant on the removal of NDMA formation potential (FP) and individual precursors is studied. During normal aerobic operation, implying a fully nitrifying system, the MBR was able to reduce NDMA precursors above 94%, however this removal percentage was reduced to values as low as 72% when changing the conditions to minimize nitrification. Removal decreased also for azithromycin (68-59%), citalopram (31-17%), venlafaxine (35-15%) and erythromycin (61-16%) on average during nitrifying versus non-nitrifying conditions. The removal of clarithromycin, o-desmethylvenlafaxine and ranitidine could not be correlated with the nitrification inhibition, as it varied greatly during the experiment time. The MBR pilot plant is coupled to a nanofiltration (NF) system and the results on the rejection of both, NDMA FP and individual precursors, through this system was above 90%. Finally, results obtained for the MBR pilot plant are compared to the percentage of removal by a conventional full scale biological wastewater treatment plant (WWTP) fed with the same influent. During aerobic operation, the removal of NDMA FP by the MBR pilot plant was similar to the full scale WWTP. PMID:27393963

  20. Developing Human Resources through Actualizing Human Potential

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    2012-01-01

    The key to human resource development is in actualizing individual and collective thinking, feeling and choosing potentials related to our minds, hearts and wills respectively. These capacities and faculties must be balanced and regulated according to the standards of truth, love and justice for individual, community and institutional development,…

  1. [Actual diet of patients with gastrointestinal diseases].

    PubMed

    Loranskaia, T I; Shakhovskaia, A K; Pavliuchkova, M S

    2000-01-01

    The study of actual nutrition of patients with erosive-ulcerative lesions in the gastroduodenal zone and of patients with operated ulcer has revealed defects in intake of essential nutrients by these patients: overeating of animal fat and refined carbohydrates, deficiency of oil, vitamins A, B2, C, D and food fibers.

  2. Humanistic Education and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1984-01-01

    Stresses the need for theoretical justification for the development of humanistic education programs in today's schools. Explores Abraham Maslow's hierarchy of needs and theory of self-actualization. Argues that Maslow's theory may be the best available for educators concerned with educating the whole child. (JHZ)

  3. Group Counseling for Self-Actualization.

    ERIC Educational Resources Information Center

    Streich, William H.; Keeler, Douglas J.

    Self-concept, creativity, growth orientation, an integrated value system, and receptiveness to new experiences are considered to be crucial variables to the self-actualization process. A regular, year-long group counseling program was conducted with 85 randomly selected gifted secondary students in the Farmington, Connecticut Public Schools. A…

  4. Teenagers' Perceived and Actual Probabilities of Pregnancy.

    ERIC Educational Resources Information Center

    Namerow, Pearila Brickner; And Others

    1987-01-01

    Explored adolescent females' (N=425) actual and perceived probabilities of pregnancy. Subjects estimated their likelihood of becoming pregnant the last time they had intercourse, and indicated the dates of last intercourse and last menstrual period. Found that the distributions of perceived probability of pregnancy were nearly identical for both…

  5. Uranium Immobilization in an Iron-Rich Rhizosphere of a Native Wetland Plant from the Savannah River Site under Reducing Conditions

    EPA Science Inventory

    The hypothesis of this study was that iron plaque formed on the roots of wetland plants and their rhizospheres create environmental conditions favorable for iron reducing bacteria that promote the in situ immobilization of uranium. Greenhouse microcosm studies were conducted usin...

  6. Arbuscular mycorrhizal symbiosis increases relative apoplastic water flow in roots of the host plant under both well-watered and drought stress conditions

    PubMed Central

    Bárzana, Gloria; Aroca, Ricardo; Paz, José Antonio; Chaumont, François; Martinez-Ballesta, Mari Carmen; Carvajal, Micaela; Ruiz-Lozano, Juan Manuel

    2012-01-01

    Background and Aims The movement of water through mycorrhizal fungal tissues and between the fungus and roots is little understood. It has been demonstrated that arbuscular mycorrhizal (AM) symbiosis regulates root hydraulic properties, including root hydraulic conductivity. However, it is not clear whether this effect is due to a regulation of root aquaporins (cell-to-cell pathway) or to enhanced apoplastic water flow. Here we measured the relative contributions of the apoplastic versus the cell-to-cell pathway for water movement in roots of AM and non-AM plants. Methods We used a combination of two experiments using the apoplastic tracer dye light green SF yellowish and sodium azide as an inhibitor of aquaporin activity. Plant water and physiological status, root hydraulic conductivity and apoplastic water flow were measured. Key Results Roots of AM plants enhanced significantly relative apoplastic water flow as compared with non-AM plants and this increase was evident under both well-watered and drought stress conditions. The presence of the AM fungus in the roots of the host plants was able to modulate the switching between apoplastic and cell-to-cell water transport pathways. Conclusions The ability of AM plants to switch between water transport pathways could allow a higher flexibility in the response of these plants to water shortage according to the demand from the shoot. PMID:22294476

  7. The mitochondrial malate dehydrogenase 1 gene GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton.

    PubMed

    Wang, Zhi-An; Li, Qing; Ge, Xiao-Yang; Yang, Chun-Lin; Luo, Xiao-Li; Zhang, An-Hong; Xiao, Juan-Li; Tian, Ying-Chuan; Xia, Gui-Xian; Chen, Xiao-Ying; Li, Fu-Guang; Wu, Jia-He

    2015-07-16

    Cotton, an important commercial crop, is cultivated for its natural fibers, and requires an adequate supply of soil nutrients, including phosphorus, for its growth. Soil phosporus exists primarily in insoluble forms. We isolated a mitochondrial malate dehydrogenase (MDH) gene, designated as GhmMDH1, from Gossypium hirsutum L. to assess its effect in enhancing P availability and absorption. An enzyme kinetic assay showed that the recombinant GhmMDH1 possesses the capacity to catalyze the interconversion of oxaloacetate and malate. The malate contents in the roots, leaves and root exudates was significantly higher in GhmMDH1-overexpressing plants and lower in knockdown plants compared with the wild-type control. Knockdown of GhmMDH1 gene resulted in increased respiration rate and reduced biomass whilst overexpression of GhmMDH1 gave rise to decreased respiration rate and higher biomass in the transgenic plants. When cultured in medium containing only insoluble phosphorus, Al-phosphorus, Fe-phosphorus, or Ca-phosphorus, GhmMDH1-overexpressing plants produced significantly longer roots and had a higher biomass and P content than WT plants, however, knockdown plants showed the opposite results for these traits. Collectively, our results show that GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton, owing to its functions in leaf respiration and P acquisition.

  8. The mitochondrial malate dehydrogenase 1 gene GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton

    PubMed Central

    Wang, Zhi-An; Li, Qing; Ge, Xiao-Yang; Yang, Chun-Lin; Luo, Xiao-Li; Zhang, An-Hong; Xiao, Juan-Li; Tian, Ying-Chuan; Xia, Gui-Xian; Chen, Xiao-Ying; Li, Fu-Guang; Wu, Jia-He

    2015-01-01

    Cotton, an important commercial crop, is cultivated for its natural fibers, and requires an adequate supply of soil nutrients, including phosphorus, for its growth. Soil phosporus exists primarily in insoluble forms. We isolated a mitochondrial malate dehydrogenase (MDH) gene, designated as GhmMDH1, from Gossypium hirsutum L. to assess its effect in enhancing P availability and absorption. An enzyme kinetic assay showed that the recombinant GhmMDH1 possesses the capacity to catalyze the interconversion of oxaloacetate and malate. The malate contents in the roots, leaves and root exudates was significantly higher in GhmMDH1-overexpressing plants and lower in knockdown plants compared with the wild-type control. Knockdown of GhmMDH1 gene resulted in increased respiration rate and reduced biomass whilst overexpression of GhmMDH1 gave rise to decreased respiration rate and higher biomass in the transgenic plants. When cultured in medium containing only insoluble phosphorus, Al-phosphorus, Fe-phosphorus, or Ca-phosphorus, GhmMDH1-overexpressing plants produced significantly longer roots and had a higher biomass and P content than WT plants, however, knockdown plants showed the opposite results for these traits. Collectively, our results show that GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton, owing to its functions in leaf respiration and P acquisition. PMID:26179843

  9. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health.

    PubMed

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M; Bauer, Rudolf; Berg, Gabriele

    2013-12-20

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants' flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome.

  10. Do Facilities with Distant Headquarters Pollute More? How Civic Engagement Conditions the Environmental Performance of Absentee Managed Plants

    ERIC Educational Resources Information Center

    Grant, Don; Jones, Andrew W.; Trautner, Mary Nell

    2004-01-01

    Scholars agree that due to advances in transportation and communication technologies, firms can extend their reach and more easily externalize their pollution by setting up plants in far-flung, less regulated areas. They also concur that absentee managed plants or facilities with remote headquarters are rapidly becoming the modal type of…

  11. Differential activity of autochthonous bacteria in controlling drought stress in native Lavandula and Salvia plants species under drought conditions in natural arid soil.

    PubMed

    Armada, Elisabeth; Roldán, Antonio; Azcon, Rosario

    2014-02-01

    The effectiveness of autochthonous plant growth-promoting rhizobacteria was studied in Lavandula dentata and Salvia officinalis growing in a natural arid Mediterranean soil under drought conditions. These bacteria identified as Bacillus megaterium (Bm), Enterobacter sp. (E), Bacillus thuringiensis (Bt), and Bacillus sp. (Bsp). Each bacteria has different potential to meliorate water limitation and alleviating drought stress in these two plant species. B. thuringiensis promoted growth and drought avoidance in Lavandula by increasing K content, by depressing stomatal conductance, and it controlled shoot proline accumulation. This bacterial effect on increasing drought tolerance was related to the decrease of glutathione reductase (GR) and ascorbate peroxidase (APX) that resulted sensitive indexes of lower cellular oxidative damage involved in the adaptative drought response in B. thuringiensis-inoculated Lavandula plants. In contrast, in Salvia, having intrinsic lower shoot/root ratio, higher stomatal conductance and lower APX and GR activities than Lavandula, the bacterial effects on nutritional, physiological and antioxidant enzymatic systems were lower. The benefit of bacteria depended on intrinsic stress tolerance of plant involved. Lavadula demonstrated a greater benefit than Salvia to control drought stress when inoculated with B. thuringiensis. The bacterial drought tolerance assessed as survival, proline, and indolacetic acid production showed the potential of this bacteria to help plants to grow under drought conditions. B. thuringiensis may be used for Lavandula plant establishment in arid environments. Particular characteristic of the plant species as low shoot/root ratio and high stomatal conductance are important factors controlling the bacterial effectiveness improving nutritional, physiological, and metabolic plant activities. PMID:24337805

  12. Arbuscular mycorrhizal symbiosis alters stomatal conductance of host plants more under drought than under amply watered conditions: a meta-analysis.

    PubMed

    Augé, Robert M; Toler, Heather D; Saxton, Arnold M

    2015-01-01

    Stomata regulate rates of carbon assimilation and water loss. Arbuscular mycorrhizal (AM) symbioses often modify stomatal behavior and therefore play pivotal roles in plant productivity. The size of the AM effect on stomatal conductance to water vapor (g s ) has varied widely, has not always been apparent, and is unpredictable. We conducted a meta-analysis of 460 studies to determine the size of the AM effect under ample watering and drought and to examine how experimental conditions have influenced the AM effect. Across all host and symbiont combinations under all soil moisture conditions, AM plants have shown 24 % higher g s than nonmycorrhizal (NM) controls. The promotion of g s has been over twice as great during moderate drought than under amply watered conditions. The AM influence on g s has been even more pronounced under severe drought, with over four times the promotion observed with ample water. Members of the Claroideoglomeraceae, Glomeraceae, and other AM families stimulated g s by about the same average amount. Colonization by native AM fungi has produced the largest promotion. Among single-AM symbionts, Glomus deserticola, Claroideoglomus etunicatum, and Funneliformis mosseae have had the largest average effects on g s across studies. Dicotyledonous hosts, especially legumes, have been slightly more responsive to AM symbiosis than monocotyledonous hosts, and C3 plants have shown over twice the AM-induced promotion of C4 plants. The extent of root colonization is important, with heavily colonized plants showing ×10 the g s promotion of lightly colonized plants. AM promotion of g s has been larger in growth chambers and in the field than in greenhouse studies, almost ×3 as large when plants were grown under high light than low light, and ×2.5 as large in purely mineral soils than in soils having an organic component. When AM plants have been compared with NM controls given NM pot culture, they have shown only half the promotion of g s as NM plants

  13. Germplasm-regression-combined (GRC) marker-trait association identification in plant breeding: a challenge for plant biotechnological breeding under soil water deficit conditions.

    PubMed

    Ruan, Cheng-Jiang; Xu, Xue-Xuan; Shao, Hong-Bo; Jaleel, Cheruth Abdul

    2010-09-01

    In the past 20 years, the major effort in plant breeding has changed from quantitative to molecular genetics with emphasis on quantitative trait loci (QTL) identification and marker assisted selection (MAS). However, results have been modest. This has been due to several factors including absence of tight linkage QTL, non-availability of mapping populations, and substantial time needed to develop such populations. To overcome these limitations, and as an alternative to planned populations, molecular marker-trait associations have been identified by the combination between germplasm and the regression technique. In the present preview, the authors (1) survey the successful applications of germplasm-regression-combined (GRC) molecular marker-trait association identification in plants; (2) describe how to do the GRC analysis and its differences from mapping QTL based on a linkage map reconstructed from the planned populations; (3) consider the factors that affect the GRC association identification, including selections of optimal germplasm and molecular markers and testing of identification efficiency of markers associated with traits; and (4) finally discuss the future prospects of GRC marker-trait association analysis used in plant MAS/QTL breeding programs, especially in long-juvenile woody plants when no other genetic information such as linkage maps and QTL are available.

  14. Plant Growth-Promoting Rhizobacteria Inoculation to Enhance Vegetative Growth, Nitrogen Fixation and Nitrogen Remobilisation of Maize under Greenhouse Conditions.

    PubMed

    Kuan, Khing Boon; Othman, Radziah; Abdul Rahim, Khairuddin; Shamsuddin, Zulkifli H

    2016-01-01

    Plant growth-promoting rhizobacteria (PGPR) may provide a biological alternative to fix atmospheric N2 and delay N remobilisation in maize plant to increase crop yield, based on an understanding that plant-N remobilisation is directly correlated to its plant senescence. Thus, four PGPR strains were selected from a series of bacterial strains isolated from maize roots at two locations in Malaysia. The PGPR strains were screened in vitro for their biochemical plant growth-promoting (PGP) abilities and plant growth promotion assays. These strains were identified as Klebsiella sp. Br1, Klebsiella pneumoniae Fr1, Bacillus pumilus S1r1 and Acinetobacter sp. S3r2 and a reference strain used was Bacillus subtilis UPMB10. All the PGPR strains were tested positive for N2 fixation, phosphate solubilisation and auxin production by in vitro tests. In a greenhouse experiment with reduced fertiliser-N input (a third of recommended fertiliser-N rate), the N2 fixation abilities of PGPR in association with maize were determined by 15N isotope dilution technique at two harvests, namely, prior to anthesis (D50) and ear harvest (D65). The results indicated that dry biomass of top, root and ear, total N content and bacterial colonisations in non-rhizosphere, rhizosphere and endosphere of maize roots were influenced by PGPR inoculation. In particular, the plants inoculated with B. pumilus S1r1 generally outperformed those with the other treatments. They produced the highest N2 fixing capacity of 30.5% (262 mg N2 fixed plant-1) and 25.5% (304 mg N2 fixed plant-1) of the total N requirement of maize top at D50 and D65, respectively. N remobilisation and plant senescence in maize were delayed by PGPR inoculation, which is an indicative of greater grain production. This is indicated by significant interactions between PGPR strains and time of harvests for parameters on N uptake and at. % 15Ne of tassel. The phenomenon is also supported by the lower N content in tassels of maize treated with

  15. Plant Growth-Promoting Rhizobacteria Inoculation to Enhance Vegetative Growth, Nitrogen Fixation and Nitrogen Remobilisation of Maize under Greenhouse Conditions.

    PubMed

    Kuan, Khing Boon; Othman, Radziah; Abdul Rahim, Khairuddin; Shamsuddin, Zulkifli H

    2016-01-01

    Plant growth-promoting rhizobacteria (PGPR) may provide a biological alternative to fix atmospheric N2 and delay N remobilisation in maize plant to increase crop yield, based on an understanding that plant-N remobilisation is directly correlated to its plant senescence. Thus, four PGPR strains were selected from a series of bacterial strains isolated from maize roots at two locations in Malaysia. The PGPR strains were screened in vitro for their biochemical plant growth-promoting (PGP) abilities and plant growth promotion assays. These strains were identified as Klebsiella sp. Br1, Klebsiella pneumoniae Fr1, Bacillus pumilus S1r1 and Acinetobacter sp. S3r2 and a reference strain used was Bacillus subtilis UPMB10. All the PGPR strains were tested positive for N2 fixation, phosphate solubilisation and auxin production by in vitro tests. In a greenhouse experiment with reduced fertiliser-N input (a third of recommended fertiliser-N rate), the N2 fixation abilities of PGPR in association with maize were determined by 15N isotope dilution technique at two harvests, namely, prior to anthesis (D50) and ear harvest (D65). The results indicated that dry biomass of top, root and ear, total N content and bacterial colonisations in non-rhizosphere, rhizosphere and endosphere of maize roots were influenced by PGPR inoculation. In particular, the plants inoculated with B. pumilus S1r1 generally outperformed those with the other treatments. They produced the highest N2 fixing capacity of 30.5% (262 mg N2 fixed plant-1) and 25.5% (304 mg N2 fixed plant-1) of the total N requirement of maize top at D50 and D65, respectively. N remobilisation and plant senescence in maize were delayed by PGPR inoculation, which is an indicative of greater grain production. This is indicated by significant interactions between PGPR strains and time of harvests for parameters on N uptake and at. % 15Ne of tassel. The phenomenon is also supported by the lower N content in tassels of maize treated with

  16. Reproducing Actual Morphology of Planetary Lava Flows

    NASA Astrophysics Data System (ADS)

    Miyamoto, H.; Sasaki, S.

    1996-03-01

    Assuming that lava flows behave as non-isothermal laminar Bingham fluids, we developed a numerical code of lava flows. We take the self gravity effects and cooling mechanisms into account. The calculation method is a kind of cellular automata using a reduced random space method, which can eliminate the mesh shape dependence. We can calculate large scale lava flows precisely without numerical instability and reproduce morphology of actual lava flows.

  17. The Actual Apollo 13 Prime Crew

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The actual Apollo 13 lunar landing mission prime crew from left to right are: Commander, James A. Lovell Jr., Command Module pilot, John L. Swigert Jr.and Lunar Module pilot, Fred W. Haise Jr. The original Command Module pilot for this mission was Thomas 'Ken' Mattingly Jr. but due to exposure to German measles he was replaced by his backup, Command Module pilot, John L. 'Jack' Swigert Jr.

  18. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health

    PubMed Central

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M.; Bauer, Rudolf; Berg, Gabriele

    2013-01-01

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants’ flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome. PMID:24391634

  19. Nuclear Energy Plant Optimization (NEPO) final report on aging and condition monitoring of low-voltage cable materials.

    SciTech Connect

    Assink, Roger Alan; Gillen, Kenneth Todd; Bernstein, Robert

    2005-11-01

    This report summarizes results generated on a 5-year cable-aging program that constituted part of the Nuclear Energy Plant Optimization (NEPO) program, an effort cosponsored by the U. S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI). The NEPO cable-aging effort concentrated on two important issues involving the development of better lifetime prediction methods as well as the development and testing of novel cable condition-monitoring (CM) techniques. To address improved life prediction methods, we first describe the use of time-temperature superposition principles, indicating how this approach improves the testing of the Arrhenius model by utilizing all of the experimentally generated data instead of a few selected and processed data points. Although reasonable superposition is often found, we show several cases where non-superposition is evident, a situation that violates the constant acceleration assumption normally used in accelerated aging studies. Long-term aging results over extended temperature ranges allow us to show that curvature in Arrhenius plots for elongation is a common occurrence. In all cases the curvature results in a lowering of the Arrhenius activation energy at lower temperatures implying that typical extrapolation of high temperature results over-estimates material lifetimes. The long-term results also allow us to test the significance of extrapolating through the crystalline melting point of semi-crystalline materials. By utilizing ultrasensitive oxygen consumption (UOC) measurements, we show that it is possible to probe the low temperature extrapolation region normally inaccessible to conventional accelerated aging studies. This allows the quantitative testing of the often-used Arrhenius extrapolation assumption. Such testing indicates that many materials again show evidence of ''downward'' curvature (E{sub a} values drop as the aging temperature is lowered) consistent with the limited elongation results and

  20. Evaluation of the magnitude and effects of bundle duct interaction in fuel assemblies at developmental plant conditions

    SciTech Connect

    Serell, D.C.; Kaplan, S.

    1980-09-01

    Purpose of this evaluation is to estimate the magnitude and effects of irradiation and creep induced fuel bundle deformations in the developmental plant. This report focuses on the trends of the results and the ability of present models to evaluate the assembly temperatures in the presence of bundle deformation. Although this analysis focuses on the developmental plant, the conclusions are applicable to LMFBR fuel assemblies in general if they have wire spacers.

  1. Gibberellin secreting rhizobacterium, Pseudomonas putida H-2-3 modulates the hormonal and stress physiology of soybean to improve the plant growth under saline and drought conditions.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Khan, Abdul Latif; Kim, Min-Ji; Park, Jae-Man; Kim, Bo-Ra; Shin, Dong-Hyun; Lee, In-Jung

    2014-11-01

    The physiological changes in tolerant soybean plants under salt and drought stress conditions with Pseudomonas putida H-2-3 were investigated. A bacterial isolate H-2-3 was isolated from soil and identified as Pseudomonas putida H-2-3 by 16S rDNA sequences. The treatment of P. putida H-2-3 significantly increased the length, fresh and dry weight of shoot and chlorophyll content in gibberellins (GAs) deficient mutant Waito-c rice seedlings over the control, it might be the presence of GA1, GA4, GA9 and GA20. The soybean plant growth was retarded in salt (120 mM sodium chloride) and drought (15% polyethylene glycol) stress conditions at 10 days treatments, while P. putida H-2-3 effectively enhanced the shoot length and fresh weight of plants suffered at salt and drought stress. The chlorophyll content was lower in abiotic stress conditions and bacterial inoculant P. putida H-2-3 mitigated the stress effects by an evidence of higher quantity of chlorophyll content in plants exposed to salt and drought. The stress hormonal analysis revealed that individual treatment of P. putida H-2-3, salt and drought significantly enhanced the abscisic acid and salicylic acid content than their control. P. putida H-2-3 applied to salt and drought stressed plants showed a lower level of abscisic acid and salicylic acid and a higher level of jasmonic acid content. Under stress condition induced by salt and drought in plants expressed higher level of total polyphenol, superoxide dismutase and radical scavenging activity and no significant changes in flavonoids. The bio-inoculant, P. putida H-2-3 modulated those antioxidants by declining superoxide dismutase, flavonoids and radical scavenging activity. P. putida H-2-3 induced tolerance against abiotic stress was confirmed by a reduction of Na content in abiotic stressed plants. The results suggest that P. putida H-2-3 application reprograms the chlorophyll, stress hormones and antioxidants expression in abiotic stress affected

  2. Flash chromatography on cartridges for the separation of plant extracts: rules for the selection of chromatographic conditions and comparison with medium pressure liquid chromatography.

    PubMed

    Weber, Petra; Hamburger, Matthias; Schafroth, Nina; Potterat, Olivier

    2011-03-01

    Empirical rules for the selection of chromatographic conditions on flash chromatography cartridges were developed, with an emphasis on gradient mode. These rules were then tested with separation of extracts from important medicinal plants including Curcuma xanthorrhiza, Piper nigrum and Salvia milthiorrhiza. Sepacore® cartridges enabled a good separation of compounds with a broad range of polarity, as typically found in plant extracts. The chromatographic resolution remained, however, lower than that achieved on classical columns packed with material of smaller particle size. For poorly soluble extracts, solid introduction gave better results than liquid injection.

  3. [Growth and development of plants in a row of generations under the conditions of space flight (experiment Greenhouse-5)

    NASA Technical Reports Server (NTRS)

    Levinskikh, M. A.; Sychev, V. N.; Derendiaeva, T. A.; Signalova, O. B.; Podol'skii, I. G.; Avdeev, S. V.; Bingheim, G. E.; Campbell, W. F. (Principal Investigator)

    2001-01-01

    Results of the experiment aimed at harvesting a second space generation of wheat var. Apogee in Mir greenhouse Svet (experiment GREENHOUSE-5) are presented. In space flight, germination rate of space seeds from the first crop made up 89% against 100% of the ground seeds. The full biological ripeness was observed in 20 plants grown from the ground seeds and one plant grown from the space seeds following 80- to 90-d vegetation. The plant of the second space generation was morphologically different neither from the species in the first space crop nor from the ground controls. To study the biological characteristics of Apogee seeds gathered in the first and second crops in spaceflight experiment GREENHOUSE-5, the seeds were planted on their return to the laboratory. Morphometric analysis showed that they were essentially similar to the controls. Hence, the space experiments in Mir greenhouse Svet performed during 1998-1999 gave proof that plants cultivated in microgravity can pass the ontogenetic cycle more than once. However, initial results of the investigations into growth and development of plants through several generations are still in-sufficient to speak of possible delayed effects of the spaceflight factors (microgravity, multicomponent radiation, harmful trace contaminants etc.).

  4. Plant Growth-Promoting Rhizobacteria Inoculation to Enhance Vegetative Growth, Nitrogen Fixation and Nitrogen Remobilisation of Maize under Greenhouse Conditions

    PubMed Central

    Kuan, Khing Boon; Othman, Radziah; Abdul Rahim, Khairuddin; Shamsuddin, Zulkifli H.

    2016-01-01

    Plant growth-promoting rhizobacteria (PGPR) may provide a biological alternative to fix atmospheric N2 and delay N remobilisation in maize plant to increase crop yield, based on an understanding that plant-N remobilisation is directly correlated to its plant senescence. Thus, four PGPR strains were selected from a series of bacterial strains isolated from maize roots at two locations in Malaysia. The PGPR strains were screened in vitro for their biochemical plant growth-promoting (PGP) abilities and plant growth promotion assays. These strains were identified as Klebsiella sp. Br1, Klebsiella pneumoniae Fr1, Bacillus pumilus S1r1 and Acinetobacter sp. S3r2 and a reference strain used was Bacillus subtilis UPMB10. All the PGPR strains were tested positive for N2 fixation, phosphate solubilisation and auxin production by in vitro tests. In a greenhouse experiment with reduced fertiliser-N input (a third of recommended fertiliser-N rate), the N2 fixation abilities of PGPR in association with maize were determined by 15N isotope dilution technique at two harvests, namely, prior to anthesis (D50) and ear harvest (D65). The results indicated that dry biomass of top, root and ear, total N content and bacterial colonisations in non-rhizosphere, rhizosphere and endosphere of maize roots were influenced by PGPR inoculation. In particular, the plants inoculated with B. pumilus S1r1 generally outperformed those with the other treatments. They produced the highest N2 fixing capacity of 30.5% (262 mg N2 fixed plant−1) and 25.5% (304 mg N2 fixed plant−1) of the total N requirement of maize top at D50 and D65, respectively. N remobilisation and plant senescence in maize were delayed by PGPR inoculation, which is an indicative of greater grain production. This is indicated by significant interactions between PGPR strains and time of harvests for parameters on N uptake and at. % 15Ne of tassel. The phenomenon is also supported by the lower N content in tassels of maize treated

  5. Indicated and actual mass inventory measurements for an inverted U-tube steam generator

    SciTech Connect

    Loomis, G.G.; Plessinger, M.P.; Boucher, T.J.

    1986-01-01

    Results from an experimental investigation of actual versus indicated secondary liquid level in a steam generator at steaming conditions are presented. The experimental investigation was performed in two different small scale U-tube-in-shell steam generators at typical pressurized water reactor operating conditions (5-7 MPa; saturated) in the Semiscale facility. During steaming conditions, the indicated secondary liquid level was found to vary considerably from the actual ''bottled-up'' liquid level. These difference between indicated and actual liquid level are related to the frictional pressure drop associated with the two-phase steaming condition in the riser. Data from a series of bottle-up experiments (Simultaneously, the primary heat source and secondary feed and steam are terminated) are tabulated and the actual liquid level is correlated to the indicated liquid level.

  6. [Growth and development of plants in a sequence of generations under the conditions of space flight (experiment Greenhouse-3)].

    PubMed

    Levinskikh, M A; Sychev, V N; Signalova, O B; Derendiaeva, T A; Podol'skiĭ, I G; Masgreĭv, M E; Bingheim, G E

    2001-01-01

    The purpose was to study characteristic features of growth and development of several plant generations in space flight in experiment GREENHOUSE-3 as a part of the Russian-US space research program MIR/NASA in 1997. The experiment consisted of cultivation of Brassica rapa L. in board greenhouse Svet. Two vegetative cycles were fully completed and the third vegetation was terminated on day 13 on the phase of budding. The total duration of the space experiment was 122 days, i.e. same as in the ground controls. In the experiment with Brassica rapa L. viable seeds produced by the first crop were planted in space flight and yielded next crop. Crops raised from the ground and space seeds were found to differ in height and number of buds. Both parameters were lowered in the plants grown from the space seeds. The prime course for smaller size and reduced organogenic potential of plantTs reproductive system seems to be a less content of nutrients in seeds that had matured in the space flight. Experiment GREENHOUSE-3 demonstrated principle feasibility of plant reproduction in space greenhouse from seeds developed in microgravity.

  7. Simulation of the plant uptake of organophosphates and other emerging pollutants for greenhouse experiments and field conditions.

    PubMed

    Trapp, Stefan; Eggen, Trine

    2013-06-01

    The uptake of the organophosphates tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tributyl phosphate (TBP), the insect repellant N,N-diethyl toluamide (DEET), and the plasticizer n-butyl benzenesulfonamide (NBBS) into plants was studied in greenhouse experiments and simulated with a dynamic physiological plant uptake model. The calibrated model was coupled to a tipping buckets soil transport model and a field scenario with sewage sludge application was simulated. High uptake of the polar, low-volatile compounds TCEP, TCPP, and DEET into plants was found, with highest concentrations in straw (leaves and stem). Uptake into carrot roots was high for TCPP and TBP. NBBS showed no high uptake but was rapidly degraded. Uptake into barley seeds was small. The pattern and levels of uptake could be reproduced by the model simulations, which indicates mainly passive uptake and transport (i.e., by the transpiration stream, with the water) into and within the plants. Also the field simulations predicted a high uptake from soil into plants of TCEP, TCPP, and DEET, while TBP is more likely taken up from air. The BCF values measured and calculated in the greenhouse study are in most cases comparable to the calculated values of the field scenario, which demonstrates that greenhouse studies can be suitable for predicting the behavior of chemicals in the field. Organophosphates have a high potential for bioaccumulation in crops and reach agricultural fields both via sewage sludge and by atmospheric deposition.

  8. Trophic relations of Opatrum sabulosum (Coleoptera, Tenebrionidae) with leaves of cultivated and uncultivated species of herbaceous plants under laboratory conditions

    PubMed Central

    Brygadyrenko, Viktor V.; Nazimov, Sergii S.

    2015-01-01

    Abstract We carried out a quantitative assessment of the consumption of herbaceous plants by Opatrum sabulosum (Linnaeus, 1761) – a highly significant agricultural pest species. We researched the feeding preferences of this pest species with respect to 33 uncultivated and 22 cultivated plant species. This species of darkling beetle feeds on many uncultivated plant species, including those with hairy leaves and bitter milky sap, such as Scabiosa ucrainca (5.21 mg/specimen/24 hours), Euphorbia virgata (3.45), Solanum nigrum (3.32), Centauria scabiosa (2.47), Lamium album (2.41), Aristolochia clematitis (1.76), Chenopodium album (1.73), Arctium lappa (1.51), Asperula odorata (1.20). A high rate of leaf consumption is also characteristic for cultivated species, for example, Perilla nankinensis (5.05 mg/specimen/24 hours), Lycopersicon esculentum (3.75), Tropaeolum majus (3.29), Nicotiana tabacum (2.66), Rumex acetosa (1.96), Beta vulgaris (1.27). Opatrum sabulosum is capable of feeding on plants which are poisonous to cattle. This species of darkling beetle consumes 95.5% of the cultivated and 48.5% of the uncultivated herbaceous plants researched. PMID:25685032

  9. [Growth and development of plants in a sequence of generations under the conditions of space flight (experiment Greenhouse-3)

    NASA Technical Reports Server (NTRS)

    Levinskikh, M. A.; Sychev, V. N.; Signalova, O. B.; Derendiaeva, T. A.; Podol'skii, I. G.; Masgreiv, M. E.; Bingheim, G. E.; Musgrave, M. E. (Principal Investigator); Campbell, W. F. (Principal Investigator)

    2001-01-01

    The purpose was to study characteristic features of growth and development of several plant generations in space flight in experiment GREENHOUSE-3 as a part of the Russian-US space research program MIR/NASA in 1997. The experiment consisted of cultivation of Brassica rapa L. in board greenhouse Svet. Two vegetative cycles were fully completed and the third vegetation was terminated on day 13 on the phase of budding. The total duration of the space experiment was 122 days, i.e. same as in the ground controls. In the experiment with Brassica rapa L. viable seeds produced by the first crop were planted in space flight and yielded next crop. Crops raised from the ground and space seeds were found to differ in height and number of buds. Both parameters were lowered in the plants grown from the space seeds. The prime course for smaller size and reduced organogenic potential of plantTs reproductive system seems to be a less content of nutrients in seeds that had matured in the space flight. Experiment GREENHOUSE-3 demonstrated principle feasibility of plant reproduction in space greenhouse from seeds developed in microgravity.

  10. Actual evapotranspiration and deficit: Biologically meaningful correlates of vegetation distribution across spatial scales

    USGS Publications Warehouse

    Stephenson, N.L.

    1998-01-01

    Correlative approaches to understanding the climatic controls of vegetation distribution have exhibited at least two important weaknesses: they have been conceptually divorced across spatial scales, and their climatic parameters have not necessarily represented aspects of climate of broad physiological importance to plants. Using examples from the literature and from the Sierra Nevada of California, I argue that two water balance parameters-actual evapotranspiration (AET) and deficit (D)-are biologically meaningful, are well correlated with the distribution of vegetation types, and exhibit these qualities over several orders of magnitude of spatial scale (continental to local). I reach four additional conclusions. (1) Some pairs of climatic parameters presently in use are functionally similar to AET and D; however, AET and D may be easier to interpret biologically. (2) Several well-known climatic parameters are biologically less meaningful or less important than AET and D, and consequently are poorer correlates of the distribution of vegetation types. Of particular interest, AET is a much better correlate of the distributions of coniferous and deciduous forests than minimum temperature. (3) The effects of evaporative demand and water availability on a site's water balance are intrinsically different. For example, the 'dry' experienced by plants on sunward slopes (high evaporative demand) is not comparable to the 'dry' experienced by plants on soils with low water-holding capacities (low water availability), and these differences are reflected in vegetation patterns. (4) Many traditional topographic moisture scalars-those that additively combine measures related to evaporative demand and water availability are not necessarily meaningful for describing site conditions as sensed by plants; the same holds for measured soil moisture. However, using AET and D in place of moisture scalars and measured soil moisture can solve these problems.

  11. Effect of C60 fullerenes on the accumulation of weathered p,p'-DDE by plant and earthworm species under single and multispecies conditions.

    PubMed

    Kelsey, Jason W; White, Jason C

    2013-04-01

    The use of engineered nanomaterials has increased dramatically in recent years, but an understanding of nanomaterial fate and effects in the environment is lacking. In particular, the interaction of nanomaterials with coexisting organic contaminants and the subsequent implications for sensitive biota is almost completely unknown. Here, the effect of C60 fullerenes on the accumulation of weathered dichlorodiphenyldichloroethylene (p,p'-DDE; DDT metabolite) by Cucurbita pepo (pumpkin) and Eisenia fetida (earthworm) was determined under single and multispecies conditions. The plants, in the presence or absence of earthworms, were grown in soil containing weathered DDE (200 ng/g) and 0 or 1,670 mg/kg C60 fullerenes. Plants and earthworms were added either simultaneously or sequentially (earthworms after plants). Neither DDE nor C60 had an impact on survival or biomass of plants and earthworms, although fullerenes significantly decreased (29.6-39.0%) the relative root mass. Under single or multispecies conditions, C60 had little impact on DDE bioaccumulation by either species. The DDE concentrations in non-fullerene-exposed shoots, roots, and earthworms were 181, 7,400, and 8,230 ng/g, respectively. On fullerene exposure, the DDE content was nonsignificantly lower at 163, 7280, and 7540 ng/g, respectively. In the presence of the earthworms, C60 significantly decreased the shoot DDE content (28.6%), but no impact on root concentrations was observed. Root DDE content was unaffected by the presence of fullerenes and decreased by 21.6 to 37.5% during coexposure with earthworms. Earthworm DDE content was decreased by plant presence. Earthworms added to soils after plant harvest accumulated more DDE but were unaffected by the C60 exposure. Additional work is necessary, but these findings suggest that fullerenes may have minimal impact on the bioaccumulation of weathered cocontaminants in soil.

  12. Will carbon isotope discrimination be useful as a tool for analysing the functional response of barley plants to salinity under the future atmospheric CO₂ conditions?

    PubMed

    Pérez-López, Usue; Mena-Petite, Amaia; Muñoz-Rueda, Alberto

    2014-09-01

    The objective of this study was to determine the response of barley's carbon isotope composition and other physiological parameters to the interaction of salt stress and elevated CO2 levels, and the usefulness of carbon isotope discrimination (Δ(13)C) as indicative of the functional performance of barley (Hordeum vulgare L.). Barley plants were grown under ambient (350 μmol mol(-1)) and elevated (700 μmol mol(-1)) CO2 conditions and subjected to salt stress (0, 80, 160, and 240 mM NaCl) for 14 days. Elevated CO2 levels increased biomass production, water use efficiency and the photosynthetic rate, although this parameter was partly acclimated to elevated CO2 levels. Salt stress decreased this acclimation response because it enhanced the sink strength of the plant. Elevated CO2 significantly decreased the (13)C isotopic composition (δ(13)C) in all plant organs; however, the ratio of δ(13)C between the root and the leaf was increased, indicating a higher allocation of δ(13)C to the below-ground parts. Conversely, salt stress increased plant δ(13)C, showing differences between plant organs. From the strong correlations between Δ(13)C and biomass production, the photosynthetic rate or water use efficiency both at ambient and elevated CO2, we concluded that Δ(13)C is a useful parameter for evaluating leaf and whole plant responses to salinity and can provide an integrated index of processes to understand the mechanisms underlying salt tolerance of barley both under current and future environmental CO2 conditions.

  13. An improved, low-cost, hydroponic system for growing Arabidopsis and other plant species under aseptic conditions

    PubMed Central

    2014-01-01

    Background 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. Results 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. Conclusions 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. PMID:24649917

  14. Air resistance measurements on actual airplane parts

    NASA Technical Reports Server (NTRS)

    Weiselsberger, C

    1923-01-01

    For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine.

  15. Explosive Percolation Transition is Actually Continuous

    NASA Astrophysics Data System (ADS)

    da Costa, R. A.; Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.

    2010-12-01

    Recently a discontinuous percolation transition was reported in a new “explosive percolation” problem for irreversible systems [D. Achlioptas, R. M. D’Souza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

  16. Power Delivery from an Actual Thermoelectric Generation System

    NASA Astrophysics Data System (ADS)

    Kaibe, Hiromasa; Kajihara, Takeshi; Nagano, Kouji; Makino, Kazuya; Hachiuma, Hirokuni; Natsuume, Daisuke

    2014-06-01

    Similar to photovoltaic (PV) and fuel cells, thermoelectric generators (TEGs) supply direct-current (DC) power, essentially requiring DC/alternating current (AC) conversion for delivery as electricity into the grid network. Use of PVs is already well established through power conditioning systems (PCSs) that enable DC/AC conversion with maximum-power-point tracking, which enables commercial use by customers. From the economic, legal, and regulatory perspectives, a commercial PCS for PVs should also be available for TEGs, preferably as is or with just simple adjustment. Herein, we report use of a PV PCS with an actual TEG. The results are analyzed, and proper application for TEGs is proposed.

  17. The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

    PubMed

    Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

    2009-04-01

    Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress.

  18. The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

    PubMed

    Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

    2009-04-01

    Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress. PMID:19396238

  19. Dataset of working conditions and thermo-economic performances for hybrid organic Rankine plants fed by solar and low-grade energy sources

    PubMed Central

    Scardigno, Domenico; Fanelli, Emanuele; Viggiano, Annarita; Braccio, Giacobbe; Magi, Vinicio

    2016-01-01

    This article provides the dataset of operating conditions of a hybrid organic Rankine plant generated by the optimization procedure employed in the research article “A genetic optimization of a hybrid organic Rankine plant for solar and low-grade energy sources” (Scardigno et al., 2015) [1]. The methodology used to obtain the data is described. The operating conditions are subdivided into two separate groups: feasible and unfeasible solutions. In both groups, the values of the design variables are given. Besides, the subset of feasible solutions is described in details, by providing the thermodynamic and economic performances, the temperatures at some characteristic sections of the thermodynamic cycle, the net power, the absorbed powers and the area of the heat exchange surfaces. PMID:27054172

  20. Dataset of working conditions and thermo-economic performances for hybrid organic Rankine plants fed by solar and low-grade energy sources.

    PubMed

    Scardigno, Domenico; Fanelli, Emanuele; Viggiano, Annarita; Braccio, Giacobbe; Magi, Vinicio

    2016-06-01

    This article provides the dataset of operating conditions of a hybrid organic Rankine plant generated by the optimization procedure employed in the research article "A genetic optimization of a hybrid organic Rankine plant for solar and low-grade energy sources" (Scardigno et al., 2015) [1]. The methodology used to obtain the data is described. The operating conditions are subdivided into two separate groups: feasible and unfeasible solutions. In both groups, the values of the design variables are given. Besides, the subset of feasible solutions is described in details, by providing the thermodynamic and economic performances, the temperatures at some characteristic sections of the thermodynamic cycle, the net power, the absorbed powers and the area of the heat exchange surfaces. PMID:27054172

  1. Dataset of working conditions and thermo-economic performances for hybrid organic Rankine plants fed by solar and low-grade energy sources.

    PubMed

    Scardigno, Domenico; Fanelli, Emanuele; Viggiano, Annarita; Braccio, Giacobbe; Magi, Vinicio

    2016-06-01

    This article provides the dataset of operating conditions of a hybrid organic Rankine plant generated by the optimization procedure employed in the research article "A genetic optimization of a hybrid organic Rankine plant for solar and low-grade energy sources" (Scardigno et al., 2015) [1]. The methodology used to obtain the data is described. The operating conditions are subdivided into two separate groups: feasible and unfeasible solutions. In both groups, the values of the design variables are given. Besides, the subset of feasible solutions is described in details, by providing the thermodynamic and economic performances, the temperatures at some characteristic sections of the thermodynamic cycle, the net power, the absorbed powers and the area of the heat exchange surfaces.

  2. Soil environmental conditions and microbial build-up mediate the effect of plant diversity on soil nitrifying and denitrifying enzyme activities in temperate grasslands.

    PubMed

    Le Roux, Xavier; Schmid, Bernhard; Poly, Franck; Barnard, Romain L; Niklaus, Pascal A; Guillaumaud, Nadine; Habekost, Maike; Oelmann, Yvonne; Philippot, Laurent; Salles, Joana Falcao; Schloter, Michael; Steinbeiss, Sibylle; Weigelt, Alexandra

    2013-01-01

    Random reductions in plant diversity can affect ecosystem functioning, but it is still unclear which components of plant diversity (species number - namely richness, presence of particular plant functional groups, or particular combinations of these) and associated biotic and abiotic drivers explain the observed relationships, particularly for soil processes. We assembled grassland communities including 1 to 16 plant species with a factorial separation of the effects of richness and functional group composition to analyze how plant diversity components influence soil nitrifying and denitrifying enzyme activities (NEA and DEA, respectively), the abundance of nitrifiers (bacterial and archaeal amoA gene number) and denitrifiers (nirK, nirS and nosZ gene number), and key soil environmental conditions. Plant diversity effects were largely due to differences in functional group composition between communities of identical richness (number of sown species), though richness also had an effect per se. NEA was positively related to the percentage of legumes in terms of sown species number, the additional effect of richness at any given legume percentage being negative. DEA was higher in plots with legumes, decreased with increasing percentage of grasses, and increased with richness. No correlation was observed between DEA and denitrifier abundance. NEA increased with the abundance of ammonia oxidizing bacteria. The effect of richness on NEA was entirely due to the build-up of nitrifying organisms, while legume effect was partly linked to modified ammonium availability and nitrifier abundance. Richness effect on DEA was entirely due to changes in soil moisture, while the effects of legumes and grasses were partly due to modified nitrate availability, which influenced the specific activity of denitrifiers. These results suggest that plant diversity-induced changes in microbial specific activity are important for facultative activities such as denitrification, whereas changes

  3. Circular distribution pattern of plant modulars and endophagous herbivory within tree crowns: the impact of roadside light conditions.

    PubMed

    Dai, Xiao-Hua; Xu, Jia-Sheng; Ding, Xing-Lu

    2013-01-01

    The circular distributions of plant modulars (branches, leaves) and endophagous herbivory (mines, galls) were investigated within the crowns of four dominant Fagaceae trees in a subtropical evergreen broadleaf forest at Jiulianshan National Nature Reserve, Jiangxi, China. The hypothesis is that more plant modulars and more endophagous herbivory should occur in the crown area perpendicular to the roads. Circular statistical techniques were used to verify new patterns of the impact of roads on plants and insects. The results confirmed that the roadside light environments had larger impacts on the circular distribution patterns of plant modulars than those of leaf herbivores. For herbivores, the impact of light was larger on mine distribution than on gall distribution. The branches of all four tree species were concentrated in the direction perpendicular to the roads. In the preferred direction, branches were longer and higher. More leaves, more mines, and more galls were found surrounding the preferred branch direction. In general, leaf miners and leaf gallers preferred leaves in the sun over those in the shade; however, leaf gallers had a lower degree of preference for sun than leaf miners. Different endphagous insects also showed clear interspecific differences in sun/shade leaf selection. PMID:24794427

  4. The Plant Cell Wall: A Complex and Dynamic Structure As Revealed by the Responses of Genes under Stress Conditions.

    PubMed

    Houston, Kelly; Tucker, Matthew R; Chowdhury, Jamil; Shirley, Neil; Little, Alan

    2016-01-01

    The plant cell wall has a diversity of functions. It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens. The cell wall must also retain some flexibility, such that when subjected to developmental, biotic, or abiotic stimuli it can be rapidly remodeled in response. Genes encoding enzymes capable of synthesizing or hydrolyzing components of the plant cell wall show differential expression when subjected to different stresses, suggesting they may facilitate stress tolerance through changes in cell wall composition. In this review we summarize recent genetic and transcriptomic data from the literature supporting a role for specific cell wall-related genes in stress responses, in both dicot and monocot systems. These studies highlight that the molecular signatures of cell wall modification are often complex and dynamic, with multiple genes appearing to respond to a given stimulus. Despite this, comparisons between publically available datasets indicate that in many instances cell wall-related genes respond similarly to different pathogens and abiotic stresses, even across the monocot-dicot boundary. We propose that the emerging picture of cell wall remodeling during stress is one that utilizes a common toolkit of cell wall-related genes, multiple modifications to cell wall structure, and a defined set of stress-responsive transcription factors that regulate them. PMID:27559336

  5. The Plant Cell Wall: A Complex and Dynamic Structure As Revealed by the Responses of Genes under Stress Conditions

    PubMed Central

    Houston, Kelly; Tucker, Matthew R.; Chowdhury, Jamil; Shirley, Neil; Little, Alan

    2016-01-01

    The plant cell wall has a diversity of functions. It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens. The cell wall must also retain some flexibility, such that when subjected to developmental, biotic, or abiotic stimuli it can be rapidly remodeled in response. Genes encoding enzymes capable of synthesizing or hydrolyzing components of the plant cell wall show differential expression when subjected to different stresses, suggesting they may facilitate stress tolerance through changes in cell wall composition. In this review we summarize recent genetic and transcriptomic data from the literature supporting a role for specific cell wall-related genes in stress responses, in both dicot and monocot systems. These studies highlight that the molecular signatures of cell wall modification are often complex and dynamic, with multiple genes appearing to respond to a given stimulus. Despite this, comparisons between publically available datasets indicate that in many instances cell wall-related genes respond similarly to different pathogens and abiotic stresses, even across the monocot-dicot boundary. We propose that the emerging picture of cell wall remodeling during stress is one that utilizes a common toolkit of cell wall-related genes, multiple modifications to cell wall structure, and a defined set of stress-responsive transcription factors that regulate them. PMID:27559336

  6. Fruit yield of virus-resistant transgenic summer squash in simulated commercial plantings under conditions of high disease pressure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit yield of transgenic crookneck summer squash ZW-20 resistant to Zucchini yellow mosaic virus (ZYMV) and Watermelon mosaic virus (WMV) and of a susceptible nontransgenic lineage of the same genotype was compared over two consecutive years. Field trials relied on small-scale plantings that refle...

  7. The study of the influence of secondary biogenic radiation on genetic and physiological changes in plants grown from seeds kept for a long time under space flight conditions

    NASA Astrophysics Data System (ADS)

    Yurov, S.; Nechitailo, G.; Dmitrievskiy, I.

    Analysis of the biological investigations carried out at the Russian space stations showed that the combined action of low radiation doses and altered gravitation causes considerable genetic and physiological changes in plants grown from seeds kept for a long time under space flight conditions The results of the investigations with tomato plants produced from seeds staying for a long time at the MIR station are presented in the work The seeds of the flight samples had 26 8 germinating capacity whereas in the control it was 58 3 To reveal hidden changes undetectable with conventional methods the method of regeneration of conditionally lethal mutations under the action of secondary biogenic radiation developed by us previously was used On the basis of preliminarily studied bacteriophage T4B mutations obtained in experiments with accelerators in highland and space flight conditions an optimal dose of Cs137 gamma-radiation in the range from 1e-2 cGy to 1e-4 cGy was chosen which generates secondary biogenic radiation The germinating capacity of the tomato seeds exposed to secondary biogenic radiation was 4 times higher as compared to the initial one and made up 75 The generations of plants exposed to the biogenic influence had specific morphological mutations cotyledon-free and leafless stumps called by us hypocotel stumps Such mutants obtained from conventionally lethal seeds under the action of biogenic radiation have never been observed in the control and experimental variants There are data for 2000 tomato mutations including

  8. An Algorithm to Estimate Field Concentrations in the Wake of a Power Plant Complex under Nonsteady Meteorological Conditions from Wind-Tunnel Experiments.

    NASA Astrophysics Data System (ADS)

    Kothari, K. M.; Meroney, R. N.; Bouwmeester, R. J. B.

    1981-08-01

    Highest concentrations of pollutant at ground level are often produced from surface sources with stable or unstable atmospheric conditions and near calm erratic winds. This paper describes a weighted data methodology developed to predict surface concentrations from stationary wind-tunnel measurements and actual meteorological wind fields. Field measurements made downwind of the Rancho Seco Nuclear Power Station in 1975 have been compared against a set of wind-tunnel measurements around a 1:500 scale model of the same facilities. The weighted data algorithm was realistic in both predicting centerline concentration values as well as the horizontal spread of the plume. On the average the wind-tunnel data combined with the weighting algorithm was some 40 times more accurate in predicting field data than the conventional Pasquill-Gifford formulas.

  9. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    PubMed

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens.

  10. Regulation of Plant Growth, Photosynthesis, Antioxidation and Osmosis by an Arbuscular Mycorrhizal Fungus in Watermelon Seedlings under Well-Watered and Drought Conditions

    PubMed Central

    Mo, Yanling; Wang, Yongqi; Yang, Ruiping; Zheng, Junxian; Liu, Changming; Li, Hao; Ma, Jianxiang; Zhang, Yong; Wei, Chunhua; Zhang, Xian

    2016-01-01

    Drought stress has become an increasingly serious environmental issue that influences the growth and production of watermelon. Previous studies found that arbuscular mycorrhizal (AM) colonization improved the fruit yield and water use efficiency (WUE) of watermelon grown under water stress; however, the exact mechanisms remain unknown. In this study, the effects of Glomus versiforme symbiosis on the growth, physio-biochemical attributes, and stress-responsive gene expressions of watermelon seedlings grown under well-watered and drought conditions were investigated. The results showed that AM colonization did not significantly influence the shoot growth of watermelon seedlings under well-watered conditions but did promote root development irrespective of water treatment. Drought stress decreased the leaf relative water content and chlorophyll concentration, but to a lesser extent in the AM plants. Compared with the non-mycorrhizal seedlings, mycorrhizal plants had higher non-photochemical quenching values, which reduced the chloroplast ultrastructural damage in the mesophyll cells and thus maintained higher photosynthetic efficiency. Moreover, AM inoculation led to significant enhancements in the enzyme activities and gene expressions of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase in watermelon leaves upon drought imposition. Consequently, AM plants exhibited lower accumulation of MDA, H2O2 and O2− compared with non-mycorrhizal plants. Under drought stress, the soluble sugar and proline contents were significantly increased, and further enhancements were observed by pre-treating the drought-stressed plants with AM. Taken together, our findings indicate that mycorrhizal colonization enhances watermelon drought tolerance through a stronger root system, greater protection of photosynthetic apparatus, a more efficient antioxidant system and improved osmoregulation. This study contributes to advances

  11. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    PubMed

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens. PMID:26469870

  12. Regulation of Plant Growth, Photosynthesis, Antioxidation and Osmosis by an Arbuscular Mycorrhizal Fungus in Watermelon Seedlings under Well-Watered and Drought Conditions.

    PubMed

    Mo, Yanling; Wang, Yongqi; Yang, Ruiping; Zheng, Junxian; Liu, Changming; Li, Hao; Ma, Jianxiang; Zhang, Yong; Wei, Chunhua; Zhang, Xian

    2016-01-01

    Drought stress has become an increasingly serious environmental issue that influences the growth and production of watermelon. Previous studies found that arbuscular mycorrhizal (AM) colonization improved the fruit yield and water use efficiency (WUE) of watermelon grown under water stress; however, the exact mechanisms remain unknown. In this study, the effects of Glomus versiforme symbiosis on the growth, physio-biochemical attributes, and stress-responsive gene expressions of watermelon seedlings grown under well-watered and drought conditions were investigated. The results showed that AM colonization did not significantly influence the shoot growth of watermelon seedlings under well-watered conditions but did promote root development irrespective of water treatment. Drought stress decreased the leaf relative water content and chlorophyll concentration, but to a lesser extent in the AM plants. Compared with the non-mycorrhizal seedlings, mycorrhizal plants had higher non-photochemical quenching values, which reduced the chloroplast ultrastructural damage in the mesophyll cells and thus maintained higher photosynthetic efficiency. Moreover, AM inoculation led to significant enhancements in the enzyme activities and gene expressions of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase in watermelon leaves upon drought imposition. Consequently, AM plants exhibited lower accumulation of MDA, H2O2 and [Formula: see text] compared with non-mycorrhizal plants. Under drought stress, the soluble sugar and proline contents were significantly increased, and further enhancements were observed by pre-treating the drought-stressed plants with AM. Taken together, our findings indicate that mycorrhizal colonization enhances watermelon drought tolerance through a stronger root system, greater protection of photosynthetic apparatus, a more efficient antioxidant system and improved osmoregulation. This study contributes

  13. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions

    PubMed Central

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400–450 ppm CO2, 18–22°C; 2) 800–850 ppm CO2, 18–22°C; 3) 400–450 ppm CO2, 22–26°C, 4) 800–850 ppm CO2, 22–26°C, 5) 400–450 ppm CO2, 26–30°C; 6) 800–850 ppm CO2, 26–30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens. PMID:26469870

  14. Nitrogen availability impacts oilseed rape (Brassica napus L.) plant water status and proline production efficiency under water-limited conditions.

    PubMed

    Albert, Benjamin; Le Cahérec, Françoise; Niogret, Marie-Françoise; Faes, Pascal; Avice, Jean-Christophe; Leport, Laurent; Bouchereau, Alain

    2012-08-01

    Large amounts of nitrogen (N) fertilizers are used in the production of oilseed rape. However, as low-input methods of crop management are introduced crops will need to withstand temporary N deficiency. In temperate areas, oilseed rape will also be affected by frequent drought periods. Here we evaluated the physiological and metabolic impact of nitrate limitation on the oilseed rape response to water deprivation. Different amounts of N fertilizer were applied to plants at the vegetative stage, which were then deprived of water and rehydrated. Both water and N depletion accelerated leaf senescence and reduced leaf development. N-deprived plants exhibited less pronounced symptoms of wilting during drought, probably because leaves were smaller and stomata were partially closed. Efficiency of proline production, a major stress-induced diversion of nitrogen metabolism, was assessed at different positions along the whole plant axis and related to leaf developmental stage and water status indices. Proline accumulation, preferentially in younger leaves, accounted for 25-85% of the free amino acid pool. This was mainly due to a better capacity for proline synthesis in fully N-supplied plants whether they were subjected to drought or not, as deduced from the expression patterns of the proline metabolism BnP5CS and BnPDH genes. Although less proline accumulated in the oldest leaves, a significant amount was transported from senescing to emerging leaves. Moreover, during rehydration proline was readily recycled. Our results therefore suggest that proline plays a significant role in leaf N remobilization and in N use efficiency in oilseed rape. PMID:22526495

  15. The actual status of Astronomy in Moldova

    NASA Astrophysics Data System (ADS)

    Gaina, A.

    The astronomical research in the Republic of Moldova after Nicolae Donitch (Donici)(1874-1956(?)) were renewed in 1957, when a satellites observations station was open in Chisinau. Fotometric observations and rotations of first Soviet artificial satellites were investigated under a program SPIN put in action by the Academy of Sciences of former Socialist Countries. The works were conducted by Assoc. prof. Dr. V. Grigorevskij, which conducted also research in variable stars. Later, at the beginning of 60-th, an astronomical Observatory at the Chisinau State University named after Lenin (actually: the State University of Moldova), placed in Lozovo-Ciuciuleni villages was open, which were coordinated by Odessa State University (Prof. V.P. Tsesevich) and the Astrosovet of the USSR. Two main groups worked in this area: first conducted by V. Grigorevskij (till 1971) and second conducted by L.I. Shakun (till 1988), both graduated from Odessa State University. Besides this research areas another astronomical observations were made: Comets observations, astroclimate and atmospheric optics in collaboration with the Institute of the Atmospheric optics of the Siberian branch of the USSR (V. Chernobai, I. Nacu, C. Usov and A.F. Poiata). Comets observations were also made since 1988 by D. I. Gorodetskij which came to Chisinau from Alma-Ata and collaborated with Ukrainean astronomers conducted by K.I. Churyumov. Another part of space research was made at the State University of Tiraspol since the beggining of 70-th by a group of teaching staff of the Tiraspol State Pedagogical University: M.D. Polanuer, V.S. Sholokhov. No a collaboration between Moldovan astronomers and Transdniestrian ones actually exist due to War in Transdniestria in 1992. An important area of research concerned the Radiophysics of the Ionosphere, which was conducted in Beltsy at the Beltsy State Pedagogical Institute by a group of teaching staff of the University since the beginning of 70-th: N. D. Filip, E

  16. MODIS Solar Diffuser: Modelled and Actual Performance

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Xiong, Xiao-Xiong; Esposito, Joe; Wang, Xin-Dong; Krebs, Carolyn (Technical Monitor)

    2001-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument's solar diffuser is used in its radiometric calibration for the reflective solar bands (VIS, NTR, and SWIR) ranging from 0.41 to 2.1 micron. The sun illuminates the solar diffuser either directly or through a attenuation screen. The attenuation screen consists of a regular array of pin holes. The attenuated illumination pattern on the solar diffuser is not uniform, but consists of a multitude of pin-hole images of the sun. This non-uniform illumination produces small, but noticeable radiometric effects. A description of the computer model used to simulate the effects of the attenuation screen is given and the predictions of the model are compared with actual, on-orbit, calibration measurements.

  17. What do tests of formal reasoning actually measure?

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.

    Tests of formal operational reasoning derived from Piagetian theory have been found to be effective predictors of academic achievement. Yet Piaget's theory regarding the underlying nature of formal operations and their employment in specific contexts has run into considerable empirical difficulty. The primary purpose of this study was to present the core of an alternative theory of the nature of advanced scientific reasoning. That theory, referred to as the multiple-hypothesis theory, argues that tests of formal operational reasoning actually measure the extent to which persons have acquired the ability to initiate reasoning with more than one specific antecedent condition, or if they are unable to imagine more than one antecedent condition, they are aware that more than one is possible; therefore conclusions that are drawn are tempered by this possibility. As a test of this multiple-hypothesis theory of advanced reasoning and the contrasting Piagetian theory of formal operations, a sample of 922 college students were first classified as concrete operational, transitional, or formal operational, based upon responses to standard Piagetian measures of formal operational reasoning. They were then administered seven logic tasks. Actual response patterns to the tasks were analyzed and found to be similar to predicted response patterns derived from the multiple-hypothesis theory and were different from those predicted by Piagetian theory. Therefore, support was obtained for the multiple-hypothesis theory. The terms intuitive and reflective were suggested to replace the terms concrete operational and formal operational to refer to persons at varying levels of intellectual development.

  18. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  19. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  20. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  1. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  2. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  3. MYB and bHLH transcription factor transgenes increase anthocyanin pigmentation in petunia and lisianthus plants, and the petunia phenotypes are strongly enhanced under field conditions

    PubMed Central

    Schwinn, Kathy E.; Boase, Murray R.; Bradley, J. Marie; Lewis, David H.; Deroles, Simon C.; Martin, Cathie R.; Davies, Kevin M.

    2014-01-01

    Petunia line Mitchell [MP, Petunia axillaris × (P. axillaris × P. hybrida)] and Eustoma grandiflorum (lisianthus) plants were produced containing a transgene for over-expression of the R2R3-MYB transcription factor [TF; ROSEA1 (ROS1)] that up-regulates flavonoid biosynthesis in Antirrhinum majus. The petunia lines were also crossed with previously produced MP lines containing a Zea mays flavonoid-related basic helix-loop-helix TF transgene (LEAF COLOR, LC), which induces strong vegetative pigmentation when these 35S:LC plants are exposed to high-light levels. 35S:ROS1 lisianthus transgenics had limited changes in anthocyanin pigmentation, specifically, precocious pigmentation of flower petals and increased pigmentation of sepals. RNA transcript levels for two anthocyanin biosynthetic genes, chalcone synthase and anthocyanidin synthase, were increased in the 35S:ROS1 lisianthus petals compared to those of control lines. With MP, the 35S:ROS1 calli showed novel red pigmentation in culture, but this was generally not seen in tissue culture plantlets regenerated from the calli or young plants transferred to soil in the greenhouse. Anthocyanin pigmentation was enhanced in the stems of mature 35S:ROS1 MP plants, but the MP white-flower phenotype was not complemented. Progeny from a 35S:ROS1 × 35S:LC cross had novel pigmentation phenotypes that were not present in either parental line or MP. In particular, there was increased pigment in the petal throat region, and the anthers changed from yellow to purple pigmentation. An outdoor field trial was conducted with the 35S:ROS1, 35S:LC, 35S:ROS1 × 35S:LC and control MP lines. Field conditions rapidly induced intense foliage pigmentation in 35S:LC plants, a phenotype not observed in control MP or equivalent 35S:LC plants maintained in a greenhouse. No difference in plant stature, seed germination, or plant survival was observed between transgenic and control plants. PMID:25414715

  4. MYB and bHLH transcription factor transgenes increase anthocyanin pigmentation in petunia and lisianthus plants, and the petunia phenotypes are strongly enhanced under field conditions.

    PubMed

    Schwinn, Kathy E; Boase, Murray R; Bradley, J Marie; Lewis, David H; Deroles, Simon C; Martin, Cathie R; Davies, Kevin M

    2014-01-01

    Petunia line Mitchell [MP, Petunia axillaris × (P. axillaris × P. hybrida)] and Eustoma grandiflorum (lisianthus) plants were produced containing a transgene for over-expression of the R2R3-MYB transcription factor [TF; ROSEA1 (ROS1)] that up-regulates flavonoid biosynthesis in Antirrhinum majus. The petunia lines were also crossed with previously produced MP lines containing a Zea mays flavonoid-related basic helix-loop-helix TF transgene (LEAF COLOR, LC), which induces strong vegetative pigmentation when these 35S:LC plants are exposed to high-light levels. 35S:ROS1 lisianthus transgenics had limited changes in anthocyanin pigmentation, specifically, precocious pigmentation of flower petals and increased pigmentation of sepals. RNA transcript levels for two anthocyanin biosynthetic genes, chalcone synthase and anthocyanidin synthase, were increased in the 35S:ROS1 lisianthus petals compared to those of control lines. With MP, the 35S:ROS1 calli showed novel red pigmentation in culture, but this was generally not seen in tissue culture plantlets regenerated from the calli or young plants transferred to soil in the greenhouse. Anthocyanin pigmentation was enhanced in the stems of mature 35S:ROS1 MP plants, but the MP white-flower phenotype was not complemented. Progeny from a 35S:ROS1 × 35S:LC cross had novel pigmentation phenotypes that were not present in either parental line or MP. In particular, there was increased pigment in the petal throat region, and the anthers changed from yellow to purple pigmentation. An outdoor field trial was conducted with the 35S:ROS1, 35S:LC, 35S:ROS1 × 35S:LC and control MP lines. Field conditions rapidly induced intense foliage pigmentation in 35S:LC plants, a phenotype not observed in control MP or equivalent 35S:LC plants maintained in a greenhouse. No difference in plant stature, seed germination, or plant survival was observed between transgenic and control plants. PMID:25414715

  5. MYB and bHLH transcription factor transgenes increase anthocyanin pigmentation in petunia and lisianthus plants, and the petunia phenotypes are strongly enhanced under field conditions.

    PubMed

    Schwinn, Kathy E; Boase, Murray R; Bradley, J Marie; Lewis, David H; Deroles, Simon C; Martin, Cathie R; Davies, Kevin M

    2014-01-01

    Petunia line Mitchell [MP, Petunia axillaris × (P. axillaris × P. hybrida)] and Eustoma grandiflorum (lisianthus) plants were produced containing a transgene for over-expression of the R2R3-MYB transcription factor [TF; ROSEA1 (ROS1)] that up-regulates flavonoid biosynthesis in Antirrhinum majus. The petunia lines were also crossed with previously produced MP lines containing a Zea mays flavonoid-related basic helix-loop-helix TF transgene (LEAF COLOR, LC), which induces strong vegetative pigmentation when these 35S:LC plants are exposed to high-light levels. 35S:ROS1 lisianthus transgenics had limited changes in anthocyanin pigmentation, specifically, precocious pigmentation of flower petals and increased pigmentation of sepals. RNA transcript levels for two anthocyanin biosynthetic genes, chalcone synthase and anthocyanidin synthase, were increased in the 35S:ROS1 lisianthus petals compared to those of control lines. With MP, the 35S:ROS1 calli showed novel red pigmentation in culture, but this was generally not seen in tissue culture plantlets regenerated from the calli or young plants transferred to soil in the greenhouse. Anthocyanin pigmentation was enhanced in the stems of mature 35S:ROS1 MP plants, but the MP white-flower phenotype was not complemented. Progeny from a 35S:ROS1 × 35S:LC cross had novel pigmentation phenotypes that were not present in either parental line or MP. In particular, there was increased pigment in the petal throat region, and the anthers changed from yellow to purple pigmentation. An outdoor field trial was conducted with the 35S:ROS1, 35S:LC, 35S:ROS1 × 35S:LC and control MP lines. Field conditions rapidly induced intense foliage pigmentation in 35S:LC plants, a phenotype not observed in control MP or equivalent 35S:LC plants maintained in a greenhouse. No difference in plant stature, seed germination, or plant survival was observed between transgenic and control plants.

  6. Influence of Tunisian aromatic plants on the prevention of oxidation in soybean oil under heating and frying conditions.

    PubMed

    Saoudi, Salma; Chammem, Nadia; Sifaoui, Ines; Bouassida-Beji, Maha; Jiménez, Ignacio A; Bazzocchi, Isabel L; Silva, Sandra Diniz; Hamdi, Moktar; Bronze, Maria Rosário

    2016-12-01

    The aim of this study was to improve the oxidative stability of soybean oil by using aromatic plants. Soybean oil flavored with rosemary (ROS) and soybean oil flavored with thyme (THY) were subjected to heating for 24h at 180°C. The samples were analyzed every 6h for their total polar compounds, anisidine values, oxidative stability and polyphenols content. The tocopherols content was determined and volatile compounds were also analyzed. After 24h of heating, the incorporation of these plants using a maceration process reduced the polar compounds by 69% and 71% respectively, in ROS and THY compared to the control. Until 6h of heating, the ROS kept the greatest oxidative stability. The use of the two extracts preserves approximately 50% of the total tocopherols content until 18h for the rosemary and 24h for the thyme flavored oils. Volatile compounds known for their antioxidant activity were also detected in the formulated oils. Aromatic plants added to the soybean oil improved the overall acceptability of potato crisps (p<0.05) until the fifteenth frying. PMID:27374561

  7. Optimization Studies of Conditions for Biological Synthesis of AuNPs in Various Shapes Using Plant Extract (Ocimum sanctum).

    PubMed

    Sneha, Krishnamurthy; Yn, Lee Shi; Yeoung-Sang, Yun

    2015-01-01

    We demonstrate the effects extract amount, pH and temperature on the formation of gold nanoparticles (AuNP) using Ocimum santum plant extract. The average AuNP size, shape, and particle number can be controlled by simply varying the pH, temperature and amount of plant extract in the reaction medium. Acidic pH was found to be ideal for the formation of AuNPs. UV-visible spectra for the reaction of the plant extract with 1 mM HAuCl4 solution showed that the highest intensity of surface plasmon resonance (SPR) occurred at pH 3. Transmission electron microscopy (TEM) showed that temperature can be used to control the aspect ratio and the relative amount of gold nanoplatelets (triangular and hexagonal). Increasing the temperature decreased the population of gold nanoplatelets and increased the number of spherical NPs, and nanoplatelet population was found to be highest at 20 degrees C and 30 degrees C. PMID:26328353

  8. Root-shoot interactions explain the reduction of leaf mineral content in Arabidopsis plants grown under elevated [CO2 ] conditions.

    PubMed

    Jauregui, Ivan; Aparicio-Tejo, Pedro M; Avila, Concepción; Cañas, Rafael; Sakalauskiene, Sandra; Aranjuelo, Iker

    2016-09-01

    Although shoot N depletion in plants exposed to elevated [CO2 ] has already been reported on several occasions, some uncertainty remains about the mechanisms involved. This study illustrates (1) the importance of characterizing root-shoot interactions and (2) the physiological, biochemical and gene expression mechanisms adopted by nitrate-fed Arabidopsis thaliana plants grown under elevated [CO2 ]. Elevated [CO2 ] increases biomass and photosynthetic rates; nevertheless, the decline in total soluble protein, Rubisco and leaf N concentrations revealed a general decrease in leaf N availability. A transcriptomic approach (conducted at the root and shoot level) revealed that exposure to 800 ppm [CO2 ] induced the expression of genes involved in the transport of nitrate and mineral elements. Leaf N and mineral status revealed that N assimilation into proteins was constrained under elevated [CO2 ]. Moreover, this study also highlights how elevated [CO2 ] induced the reorganization of nitrate assimilation between tissues; root nitrogen assimilation was favored over leaf assimilation to offset the decline in nitrogen metabolism in the leaves of plants exposed to elevated [CO2 ].

  9. Influence of Tunisian aromatic plants on the prevention of oxidation in soybean oil under heating and frying conditions.

    PubMed

    Saoudi, Salma; Chammem, Nadia; Sifaoui, Ines; Bouassida-Beji, Maha; Jiménez, Ignacio A; Bazzocchi, Isabel L; Silva, Sandra Diniz; Hamdi, Moktar; Bronze, Maria Rosário

    2016-12-01

    The aim of this study was to improve the oxidative stability of soybean oil by using aromatic plants. Soybean oil flavored with rosemary (ROS) and soybean oil flavored with thyme (THY) were subjected to heating for 24h at 180°C. The samples were analyzed every 6h for their total polar compounds, anisidine values, oxidative stability and polyphenols content. The tocopherols content was determined and volatile compounds were also analyzed. After 24h of heating, the incorporation of these plants using a maceration process reduced the polar compounds by 69% and 71% respectively, in ROS and THY compared to the control. Until 6h of heating, the ROS kept the greatest oxidative stability. The use of the two extracts preserves approximately 50% of the total tocopherols content until 18h for the rosemary and 24h for the thyme flavored oils. Volatile compounds known for their antioxidant activity were also detected in the formulated oils. Aromatic plants added to the soybean oil improved the overall acceptability of potato crisps (p<0.05) until the fifteenth frying.

  10. Root-shoot interactions explain the reduction of leaf mineral content in Arabidopsis plants grown under elevated [CO2 ] conditions.

    PubMed

    Jauregui, Ivan; Aparicio-Tejo, Pedro M; Avila, Concepción; Cañas, Rafael; Sakalauskiene, Sandra; Aranjuelo, Iker

    2016-09-01

    Although shoot N depletion in plants exposed to elevated [CO2 ] has already been reported on several occasions, some uncertainty remains about the mechanisms involved. This study illustrates (1) the importance of characterizing root-shoot interactions and (2) the physiological, biochemical and gene expression mechanisms adopted by nitrate-fed Arabidopsis thaliana plants grown under elevated [CO2 ]. Elevated [CO2 ] increases biomass and photosynthetic rates; nevertheless, the decline in total soluble protein, Rubisco and leaf N concentrations revealed a general decrease in leaf N availability. A transcriptomic approach (conducted at the root and shoot level) revealed that exposure to 800 ppm [CO2 ] induced the expression of genes involved in the transport of nitrate and mineral elements. Leaf N and mineral status revealed that N assimilation into proteins was constrained under elevated [CO2 ]. Moreover, this study also highlights how elevated [CO2 ] induced the reorganization of nitrate assimilation between tissues; root nitrogen assimilation was favored over leaf assimilation to offset the decline in nitrogen metabolism in the leaves of plants exposed to elevated [CO2 ]. PMID:26801348

  11. [A protector effect of cytokinin preparations on the photosynthetic apparatus of wheat plants under water deficiency conditions].

    PubMed

    Monakhova, O F; Cherniad'ev, I I

    2007-01-01

    The protective effects of the cytokinin 6-benzylaminopurine and the compounds thidiazuron and kartolin, displaying a cytokinin activity, on the photosynthetic apparatus of young seedlings and leaves of adult plants of two wheat (Triticum aestivum L.) cultivars, Mironovskaya 808 (more drought tolerant) and Lutescens 758 (less tolerant to water stress), were compared on the background of an increasing water deficiency. At the stages of drought and subsequent rehydration, cartolin preparations were the most efficient protectors, enhancing a less pronounced decrease in the intensity of photosynthesis, carboxylating activity of the key enzyme of carbon metabolism--ribulose bisphosphate carboxylase/oxygenase (EC 4.1.1.39)-and the activity of NADP-glyceraldehyde phosphate dehydrogenase--the enzyme complex comprising phosphoglycerate kinase (EC 2.7.2.3) and glyceraldehyde phosphate dehydrogenase (EC 1.2.1.13). This effect also included an increase in the leaf specific density and plant productivity. The negative influence of water stress on the photosynthetic apparatus was more pronounced in a less tolerant cultivar Lutescens 758 and in the seedlings as compared with the adult plants. PMID:18173117

  12. CONDITIONING TECHNOLOGY FOR RADIOACTIVE WASTE RESULTED FROM THE TREATMENT OF LIQUID WASTE FROM THE ROMANIAN NUCLEAR POWER PLANT

    SciTech Connect

    ARSENE, CARMEN; ANDREI, VERONICA; NEGOIU, DUMITRU

    2003-02-27

    For the conditioning of spent resins contaminated with radionuclides, such as: 137Cs, 134Cs, 60Co, 58Co, 57Co, 54Mn, etc., techniques of direct immobilization in cement, bitumen and organic polymers have been tested. The selected process was the bituminization using industrial bitumen, I 60-70, made in Romania, which had very good characteristics. The paper presents stages of the research project, technical conditions for the process and advantages of the bituminization of spent resins.

  13. Near-field krypton-85 measurements in stable meteorological conditions around the AREVA NC La Hague reprocessing plant: estimation of atmospheric transfer coefficients.

    PubMed

    Connan, O; Solier, L; Hébert, D; Maro, D; Lamotte, M; Voiseux, C; Laguionie, P; Cazimajou, O; Le Cavelier, S; Godinot, C; Morillon, M; Thomas, L; Percot, S

    2014-11-01

    The aim of this work was to study the near-field dispersion of (85)Kr around the nuclear fuel reprocessing plant at La Hague (AREVA NC La Hague - France) under stable meteorological conditions. Twenty-two (85)Kr night-time experimental campaigns were carried out at distances of up to 4 km from the release source. Although the operational Gaussian models predict for these meteorological conditions a distance to plume touchdown of several kilometers, we almost systematically observed a marked ground signal at distances of 0.5-4 km. The calculated atmospheric transfer coefficients (ATC) show values (1) higher than those observed under neutral conditions, (2) much higher than those proposed by the operational models, and (3) higher than those used in the impact assessments.

  14. Near-field krypton-85 measurements in stable meteorological conditions around the AREVA NC La Hague reprocessing plant: estimation of atmospheric transfer coefficients.

    PubMed

    Connan, O; Solier, L; Hébert, D; Maro, D; Lamotte, M; Voiseux, C; Laguionie, P; Cazimajou, O; Le Cavelier, S; Godinot, C; Morillon, M; Thomas, L; Percot, S

    2014-11-01

    The aim of this work was to study the near-field dispersion of (85)Kr around the nuclear fuel reprocessing plant at La Hague (AREVA NC La Hague - France) under stable meteorological conditions. Twenty-two (85)Kr night-time experimental campaigns were carried out at distances of up to 4 km from the release source. Although the operational Gaussian models predict for these meteorological conditions a distance to plume touchdown of several kilometers, we almost systematically observed a marked ground signal at distances of 0.5-4 km. The calculated atmospheric transfer coefficients (ATC) show values (1) higher than those observed under neutral conditions, (2) much higher than those proposed by the operational models, and (3) higher than those used in the impact assessments. PMID:25078471

  15. A greenhouse trial to investigate the ameliorative properties of biosolids and plants on physicochemical conditions of iron ore tailings: Implications for an iron ore mine site remediation.

    PubMed

    Cele, Emmanuel Nkosinathi; Maboeta, Mark

    2016-01-01

    An iron ore mine site in Swaziland is currently (2015) in a derelict state as a consequence of past (1964-1988) and present (2011 - current) iron ore mining operations. In order to control problems associated with mine wastes, the Swaziland Water Services Corporation (SWSC) recently (2013) proposed the application of biosolids in sites degraded by mining operations. It is thought that this practice could generally improve soil conditions and enhance plant reestablishment. More importantly, the SWSC foresees this as a potential solution to the biosolids disposal problems. In order to investigate the effects of biosolids and plants in soil physicochemical conditions of iron mine soils, we conducted two plant growth trials. Trial 1 consisted of tailings that received biosolids and topsoil (TUSB mix) while in trial 2, tailings received biosolids only (TB mix). In the two trials, the application rates of 0 (control), 10, 25, 50, 75 and 100 t ha(-1) were used. After 30 days of equilibration, 25 seeds of Cynodon dactylon were sown in each pot and thinned to 10 plants after 4 weeks. Plants were watered twice weekly and remained under greenhouse conditions for 12 weeks, subsequent to which soils were subjected to chemical analysis. According to the results obtained, there were significant improvements in soil parameters related to fertility such as organic matter (OM), water holding capacity (WHC), cation exchange capacity (CEC), ammonium [Formula: see text] , magnesium (Mg(2+)), calcium (Ca(2+)) and phosphorus ( [Formula: see text] ). With regard to heavy metals, biosolids led to significant increases in soil total concentrations of Cu, Zn, Cd, Hg and Pb. The higher concentrations of Zn and Cu in treated tailings compared to undisturbed adjacent soils are a cause for concern because in the field, this might work against the broader objectives of mine soil remediation, which include the recolonization of reclaimed sites by soil-dwelling organisms. Therefore, while

  16. A greenhouse trial to investigate the ameliorative properties of biosolids and plants on physicochemical conditions of iron ore tailings: Implications for an iron ore mine site remediation.

    PubMed

    Cele, Emmanuel Nkosinathi; Maboeta, Mark

    2016-01-01

    An iron ore mine site in Swaziland is currently (2015) in a derelict state as a consequence of past (1964-1988) and present (2011 - current) iron ore mining operations. In order to control problems associated with mine wastes, the Swaziland Water Services Corporation (SWSC) recently (2013) proposed the application of biosolids in sites degraded by mining operations. It is thought that this practice could generally improve soil conditions and enhance plant reestablishment. More importantly, the SWSC foresees this as a potential solution to the biosolids disposal problems. In order to investigate the effects of biosolids and plants in soil physicochemical conditions of iron mine soils, we conducted two plant growth trials. Trial 1 consisted of tailings that received biosolids and topsoil (TUSB mix) while in trial 2, tailings received biosolids only (TB mix). In the two trials, the application rates of 0 (control), 10, 25, 50, 75 and 100 t ha(-1) were used. After 30 days of equilibration, 25 seeds of Cynodon dactylon were sown in each pot and thinned to 10 plants after 4 weeks. Plants were watered twice weekly and remained under greenhouse conditions for 12 weeks, subsequent to which soils were subjected to chemical analysis. According to the results obtained, there were significant improvements in soil parameters related to fertility such as organic matter (OM), water holding capacity (WHC), cation exchange capacity (CEC), ammonium [Formula: see text] , magnesium (Mg(2+)), calcium (Ca(2+)) and phosphorus ( [Formula: see text] ). With regard to heavy metals, biosolids led to significant increases in soil total concentrations of Cu, Zn, Cd, Hg and Pb. The higher concentrations of Zn and Cu in treated tailings compared to undisturbed adjacent soils are a cause for concern because in the field, this might work against the broader objectives of mine soil remediation, which include the recolonization of reclaimed sites by soil-dwelling organisms. Therefore, while

  17. Citricoccus zhacaiensis B-4 (MTCC 12119) a novel osmotolerant plant growth promoting actinobacterium enhances onion (Allium cepa L.) seed germination under osmotic stress conditions.

    PubMed

    Selvakumar, Govindan; Bhatt, Ravindra M; Upreti, Kaushal K; Bindu, Gurupadam Hema; Shweta, Kademani

    2015-05-01

    The water potential of rhizospheric soil is a key parameter that determines the availability of water, oxygen, and nutrients to plants and microbes. Recent global warming trends and erratic precipitation patterns have resulted in the emergence of drought as a major constraint of agricultural productivity. Though several strategies are being evaluated to address this issue, a novel approach is the utilization of microbes for alleviation of drought stress effects in crops. Citricoccus zhacaiensis B-4 is an osmotolerant actinobacterium isolated from banana rhizosphere on mannitol supplemented medium (-2.92 MPa osmotic potential). This isolate expressed plant growth promotion traits viz, IAA, GA3 production, phosphate, zinc solubilization, ACC deaminase activity and ammonia production under PEG induced osmotic stress and non-stress conditions. Under in vitro osmotic conditions, biopriming with the actinobacterium improved the percent germination, seedling vigour and germination rate of onion seeds (cv. Arka Kalyan) at osmotic potentials up to -0.8 MPa. Considering its novelty, osmotolerance and plant growth promoting traits, biopriming with C. zhacaiensis is suggested as a viable option for the promotion of onion seed germination under drought stressed environments.

  18. Proposed criteria for identifying GE crop plants that pose a low or negligible risk to the environment under conditions of low-level presence in seed.

    PubMed

    Roberts, Andrew; Finardi-Filho, Flavio; Hegde, Subray; Kiekebusch, Juan; Klimpel, Gonzalo; Krieger, Mark; Lema, Martin A; Macdonald, Philip; Nari, Claudia; Rubinstein, Clara; Slutsky, Bernice; Vicien, Carmen

    2015-10-01

    The low-level presence (LLP) of genetically engineered (GE) seeds that have been approved in the country of origin but not the country of import presents challenges for regulators in both seed importing and exporting countries, as well as for the international seed trade and the farmers who rely on it. In addition to legal, financial and regulatory challenges, such LLP situations in seed may also require an environmental risk assessment by the country of import. Such assessments have typically been informed by the national framework established to support decisions related to wide scale cultivation, and frequently do not take into account the low environmental exposure and prior regulatory history of the GE plant. In addition, such assessment processes may not be well suited to the decision-making timeframe that is necessary when dealing with an LLP situation in imported seed. In order to facilitate regulatory decision making, this paper proposes a set of scientific criteria for identifying GE crop plants that are expected to pose a low or negligible risk to the environment under LLP conditions in seed. Regulatory decision makers in some importing countries may decide to use these criteria to assist in risk analysis associated with LLP situations they are experiencing or could experience in the future, and might choose to proactively apply the criteria to identify existing GE plants with regulatory approvals in other countries that would be expected to pose low risk under conditions of LLP in seed. PMID:26264890

  19. Effect of 1-naphthaleneacetic acid on organic acid exudation by the roots of white lupin plants grown under phosphorus-deficient conditions.

    PubMed

    Gómez, Diego A; Carpena, Ramón O

    2014-09-15

    The effect of NAA (1-naphthaleneacetic acid) on organic acid exudation in white lupin plants grown under phosphorus deficiency was investigated. Plants were sampled periodically for collecting of organic acids (citrate, malate, succinate), and also were used to study the effect on proton extrusion and release of Na(+), K(+), Ca(2+) and Mg(2+). The tissues were later processed to quantify the organic acids in tissues, the phosphorus content and the effects on plant biomass. The exogenous addition of NAA led to an increase in organic acid exudation, but this response was not proportional to the concentration of the dose applied, noticing the largest increments with NAA 10(-8)M. In contrast the increase in root weight was proportional to the dose applied, which shows that with higher doses the roots produced are not of proteoid type. Proton extrusion and the release of cations were related to the NAA dose, the first was proportional to the dose applied and the second inversely proportional. Regarding the analysis of tissues, the results of citrate and phosphorus content in shoots show that the overall status of these parts are the main responsible of the organic acids exuded. NAA served as an enhancer of the organic acid exudation that occurs under phosphorus deficient conditions, with a response that depends on the dose applied, not only in its magnitude, but also in the mechanism of action of the plant hormone. PMID:25046756

  20. On the role of plant mitochondrial metabolism and its impact on photosynthesis in both optimal and sub-optimal growth conditions.

    PubMed

    Araújo, Wagner L; Nunes-Nesi, Adriano; Fernie, Alisdair R

    2014-02-01

    Given that the pathways of photosynthesis and respiration catalyze partially opposing processes, it follows that their relative activities must be carefully regulated within plant cells. Recent evidence has shown that the components of the mitochondrial electron transport chain are essential for the proper maintenance of intracellular redox gradients, to allow considerable rates of photorespiration and in turn efficient photosynthesis. Thus considerable advances have been made in understanding the interaction between respiration and photosynthesis during the last decades and the potential mechanisms linking mitochondrial function and photosynthetic efficiency will be reviewed. Despite the fact that manipulation of various steps of mitochondrial metabolism has been demonstrated to alter photosynthesis under optimal growth conditions, it is likely that these changes will, by and large, not be maintained under sub-optimal situations. Therefore producing plants to meet this aim remains a critical challenge. It is clear, however, that although there have been a range of studies analysing changes in respiratory and photosynthetic rates in response to light, temperature and CO2, our knowledge of the environmental impact on these processes and its linkage still remains fragmented. We will also discuss the metabolic changes associated to plant respiration and photosynthesis as important components of the survival strategy as they considerably extend the period that a plant can withstand to a stress situation.

  1. Effect of 1-naphthaleneacetic acid on organic acid exudation by the roots of white lupin plants grown under phosphorus-deficient conditions.

    PubMed

    Gómez, Diego A; Carpena, Ramón O

    2014-09-15

    The effect of NAA (1-naphthaleneacetic acid) on organic acid exudation in white lupin plants grown under phosphorus deficiency was investigated. Plants were sampled periodically for collecting of organic acids (citrate, malate, succinate), and also were used to study the effect on proton extrusion and release of Na(+), K(+), Ca(2+) and Mg(2+). The tissues were later processed to quantify the organic acids in tissues, the phosphorus content and the effects on plant biomass. The exogenous addition of NAA led to an increase in organic acid exudation, but this response was not proportional to the concentration of the dose applied, noticing the largest increments with NAA 10(-8)M. In contrast the increase in root weight was proportional to the dose applied, which shows that with higher doses the roots produced are not of proteoid type. Proton extrusion and the release of cations were related to the NAA dose, the first was proportional to the dose applied and the second inversely proportional. Regarding the analysis of tissues, the results of citrate and phosphorus content in shoots show that the overall status of these parts are the main responsible of the organic acids exuded. NAA served as an enhancer of the organic acid exudation that occurs under phosphorus deficient conditions, with a response that depends on the dose applied, not only in its magnitude, but also in the mechanism of action of the plant hormone.

  2. Variation of glycyrrhizin and liquiritin contents within a population of 5-year-old licorice (Glycyrrhiza uralensis) plants cultivated under the same conditions.

    PubMed

    Kojoma, Mareshige; Hayashi, Shigeki; Shibata, Toshiro; Yamamoto, Yutaka; Sekizaki, Haruo

    2011-01-01

    Cultivated licorice plants (Glycyrrhiza uralensis FISCH.) contain smaller amounts of the triterpene saponin glycyrrhizin than wild licorice plants. To resolve this problem and to breed strains with high-glycyrrhizin content we determined the glycyrrhizin content of 100 samples of G. uralensis that were propagated from seed and grown under the same conditions in the field for 5 years. There was a 10.2-fold variation in glycyrrhizin content among these plants, ranging from 0.46 to 4.67% (average 2.11±0.90%). There was also a wide variation in liquiritin content, ranging from 0.11 to 2.65% (average 1.00±0.49%). The glycyrrhizin content was positively correlated with that of liquiritin in the taproots (r(2)=0.5525). Our results indicate that there are various genetic strains for glycyrrhizin and liquiritin synthesis within a population of plants propagated from seed. The selected high-glycyrrhizin and liquiritin strains will be useful for licorice production and studies on biosynthetic analysis of glycyrrhizin and liquiritin.

  3. Exchange of atmospheric formic and acetic acids with trees and crop plants under controlled chamber and purified air conditions

    NASA Astrophysics Data System (ADS)

    Kesselmeier, J.; Bode, K.; Gerlach, C.; Jork, E.-M.

    We investigated the exchange of formic and acetic acids between the atmosphere and various tree species such as beech ( Fagus sylvatica L.), ash ( Fraxinus excelsior L.), spruce ( Picea abies L.) Karst, holm oak ( Quercus ilex L.), and birch ( Betula pendula L.). and some crop-plant species such as corn ( Zea mays, var. Banjo), pea ( Pisum sativum, var. Solara), barley ( Hordeum vulgare, var. Igri) and oat (Avena sativa, var. Wiesel). All experiments were done with dynamic enclosures flushed with purified oxidant-free air, containing only low or controlled amounts of the two acids. Significant and light-triggered emission of both acids from all tree species was observed. For one tree species (ash) a seasonal large increase in fall due to early leaf decomposition was found. The standard emission factors (30°C and PAR=1000 μmol m 2 s -1) given as (nmol m -2 min -1) for acetic and formic acids, respectively, were 8.1 and 29.7 (ash, autumn), 1.0 and 3.3 (ash, summer), 0.9 and 1.4 (beech), 0.7 and 1.45 (spruce), 1.9 and 2.4 (Holm oak) and 1.7 and 6.7 (birch). Rough estimation of global annual emissions range between 20 and 130 Gmol formic acid and 10 and 33 Gmol acetic acid. These numbers reflect a 15-30% contribution by forest emissions to the continental organic acid budget. As compared to the global total NMHC emissions low molecular weight organic acids are of minor importance. In contrast to the trees, none of the crop-plant species investigated showed an emission, but always a clear deposition of both acids. Both emission from trees as well as uptake by the agricultural plants could be related to transpiration rates and leaf conductances.

  4. Transcriptome Profiling of the Potato (Solanum tuberosum L.) Plant under Drought Stress and Water-Stimulus Conditions

    PubMed Central

    Gong, Lei; Zhang, Hongxia; Gan, Xiaoyan; Zhang, Li; Chen, Yuchao; Nie, Fengjie; Shi, Lei; Li, Miao; Guo, Zhiqian; Zhang, Guohui; Song, Yuxia

    2015-01-01

    Drought stress can seriously affect tuberization, yield and quality of potato plant. However, the precise molecular mechanisms governing potato stolon’s response to drought stress and water supply are not very well understood. In this work, a potato (Solanum tuberosum L.) variant, Ningshu 4, was subjected to severe drought stress treatment (DT) and re-watering treatment (RWT) at tuber bulking stage. Strand-specific cDNA libraries of stolon materials were constructed for paired-end transcriptome sequencing analyses and differentially expressed gene (DEG) examination. In comparison to untreated-control (CT) plants, 3189 and 1797 DEGs were identified in DT and RWT plants and 4154 solely expressed DEGs were screened out from these two comparison groups. Interestingly, 263 genes showed opposite expression patterns in DT and RWT plants. Among them, genes homologous to Protein Phosphatase 2C (PP2C), Aspartic protease in guard cell 1 (ASPG1), auxin-responsive protein, Arabidopsis pseudo response regualtor 2 (APRR2), GA stimulated transcripts in Arabidopsis 6 (GASA6), Calmodulin-like protein 19 (CML19), abscisic acid 8'-hydroxylases and calcium-transporting ATPase, et al. were related with drought-stress and water stimulus response. Sixteen DEGs involved in starch synthesis, accumulation and tuber formation exhibited significantly different expression upon re-watering. In addition, 1630, 1527 and 1596 transcription factor encoding genes were detected in CT, DT and RWT. DEGs of ERF, bHLH, MYB, NAC, WRKY, C2H2, bZIP and HD-ZIP families accounted for 50% in three comparison groups, respectively. Furthermore, characteristics of 565 gene ontology (GO) and 108 Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) were analyzed with the 4154 DEGs. All these results suggest that the drought- and water-stimulus response could be implemented by the regulated expression of metabolic pathway DEGs, and these genes were involved in the endogenous hormone biosynthesis and signal

  5. Transcriptome Profiling of the Potato (Solanum tuberosum L.) Plant under Drought Stress and Water-Stimulus Conditions.

    PubMed

    Gong, Lei; Zhang, Hongxia; Gan, Xiaoyan; Zhang, Li; Chen, Yuchao; Nie, Fengjie; Shi, Lei; Li, Miao; Guo, Zhiqian; Zhang, Guohui; Song, Yuxia

    2015-01-01

    Drought stress can seriously affect tuberization, yield and quality of potato plant. However, the precise molecular mechanisms governing potato stolon's response to drought stress and water supply are not very well understood. In this work, a potato (Solanum tuberosum L.) variant, Ningshu 4, was subjected to severe drought stress treatment (DT) and re-watering treatment (RWT) at tuber bulking stage. Strand-specific cDNA libraries of stolon materials were constructed for paired-end transcriptome sequencing analyses and differentially expressed gene (DEG) examination. In comparison to untreated-control (CT) plants, 3189 and 1797 DEGs were identified in DT and RWT plants and 4154 solely expressed DEGs were screened out from these two comparison groups. Interestingly, 263 genes showed opposite expression patterns in DT and RWT plants. Among them, genes homologous to Protein Phosphatase 2C (PP2C), Aspartic protease in guard cell 1 (ASPG1), auxin-responsive protein, Arabidopsis pseudo response regualtor 2 (APRR2), GA stimulated transcripts in Arabidopsis 6 (GASA6), Calmodulin-like protein 19 (CML19), abscisic acid 8'-hydroxylases and calcium-transporting ATPase, et al. were related with drought-stress and water stimulus response. Sixteen DEGs involved in starch synthesis, accumulation and tuber formation exhibited significantly different expression upon re-watering. In addition, 1630, 1527 and 1596 transcription factor encoding genes were detected in CT, DT and RWT. DEGs of ERF, bHLH, MYB, NAC, WRKY, C2H2, bZIP and HD-ZIP families accounted for 50% in three comparison groups, respectively. Furthermore, characteristics of 565 gene ontology (GO) and 108 Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) were analyzed with the 4154 DEGs. All these results suggest that the drought- and water-stimulus response could be implemented by the regulated expression of metabolic pathway DEGs, and these genes were involved in the endogenous hormone biosynthesis and signal

  6. Caustic-Side Solvent Extraction: Prediction of Cesium Extraction for Actual Wastes and Actual Waste Simulants

    SciTech Connect

    Delmau, L.H.; Haverlock, T.J.; Sloop, F.V., Jr.; Moyer, B.A.

    2003-02-01

    This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. It was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios.

  7. A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions

    PubMed Central

    Rosenberg, Yvonne J.; Walker, Jeremy; Jiang, Xiaoming; Donahue, Scott; Robosky, Jason; Sack, Markus; Lees, Jonathan; Urban, Lori

    2015-01-01

    Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1–2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product. PMID:26268538

  8. D-Root: a system for cultivating plants with the roots in darkness or under different light conditions.

    PubMed

    Silva-Navas, Javier; Moreno-Risueno, Miguel A; Manzano, Concepción; Pallero-Baena, Mercedes; Navarro-Neila, Sara; Téllez-Robledo, Bárbara; Garcia-Mina, Jose M; Baigorri, Roberto; Gallego, Francisco Javier; del Pozo, Juan C

    2015-10-01

    In nature roots grow in the dark and away from light (negative phototropism). However, most current research in root biology has been carried out with the root system grown in the presence of light. Here, we have engineered a device, called Dark-Root (D-Root), to grow plants in vitro with the aerial part exposed to the normal light/dark photoperiod while the roots are in the dark or exposed to specific wavelengths or light intensities. D-Root provides an efficient system for cultivating a large number of seedlings and easily characterizing root architecture in the dark. At the morphological level, root illumination shortens root length and promotes early emergence of lateral roots, therefore inducing expansion of the root system. Surprisingly, root illumination also affects shoot development, including flowering time. Our analyses also show that root illumination alters the proper response to hormones or abiotic stress (e.g. salt or osmotic stress) and nutrient starvation, enhancing inhibition of root growth. In conclusion, D-Root provides a growing system closer to the natural one for assaying Arabidopsis plants, and therefore its use will contribute to a better understanding of the mechanisms involved in root development, hormonal signaling and stress responses.

  9. Anther culture in Helianthus annuus L., influence of genotype and culture conditions on embryo induction and plant regeneration.

    PubMed

    Thengane, S R; Joshi, M S; Khuspe, S S; Mascarenhas, A F

    1994-01-01

    Production of microspore-derived embryos from cultured anthers is now a well established technique for the isolation of homozygous lines in many crop plants. We describe here a culture method for embryo induction and plant regeneration from anthers of four sunflower genotypes. For preliminary experiments, anthers of uninucleate microspores were cultured on four types of basal media viz., Murashige and Skoog's MS, Gamborg's B5, Nitsch and Nitsch, and White's W, supplemented with 1.0 mg/l 2,4 dichlorophenoxy acetic acid and 0.5 mg/l 6-benzylaminopurine and 40 g/l sucrose. MS basal medium, being more responsive for embryo induction, was used for further experimentation. To optimise the culture requirement MS basal medium was supplemented with 0.2-2.0 mg/l 2,4 dichlorophenoxy acetic acid and 0.5 and 1.0 mg/l 6-benzylaminopurine. The effect of cold pretreatment, hormone regime and sucrose concentration were tested for embryogenic efficiency. Genotype had a significant effect on the capacity of embryo induction. Addition of silver nitrate (2.5 mg/l), an ethylene inhibitor, stimulated embryo germination. Plantlets were obtained (10-15%) from embryos of only one genotype.

  10. A nightly conditioning method to reduce parasitic power consumption in molten-salt central-receiver solar-power plants

    SciTech Connect

    Pacheco, J.E.

    1995-06-01

    A method to reduce nightly parasitic power consumption in a molten salt central receiver is discussed where salt is drained from the piping and heat tracing is turned off to allow the piping to cool to ambient overnight, then in the morning the pipes are filled while they are cold. Since the piping and areas of the receiver in a molten-nitrate salt central-receiver solar power plant must be electrically heated to maintain their temperatures above the nitrate salt freezing point (430{degrees}F, 221{degrees}C), considerable energy could be used to maintain such temperatures during nightly shut down and bad weather. Experiments and analyses have been conducted to investigate cold filling receiver panels and piping as a way of reducing parasitic electrical power consumption and increasing the availability of the plant. The two major concerns with cold filling are: (1) how far can the molten salt penetrate cold piping before freezing closed and (2) what thermal stresses develop during the associated thermal shock. Experiments and analysis are discussed.

  11. D-Root: a system for cultivating plants with the roots in darkness or under different light conditions.

    PubMed

    Silva-Navas, Javier; Moreno-Risueno, Miguel A; Manzano, Concepción; Pallero-Baena, Mercedes; Navarro-Neila, Sara; Téllez-Robledo, Bárbara; Garcia-Mina, Jose M; Baigorri, Roberto; Gallego, Francisco Javier; del Pozo, Juan C

    2015-10-01

    In nature roots grow in the dark and away from light (negative phototropism). However, most current research in root biology has been carried out with the root system grown in the presence of light. Here, we have engineered a device, called Dark-Root (D-Root), to grow plants in vitro with the aerial part exposed to the normal light/dark photoperiod while the roots are in the dark or exposed to specific wavelengths or light intensities. D-Root provides an efficient system for cultivating a large number of seedlings and easily characterizing root architecture in the dark. At the morphological level, root illumination shortens root length and promotes early emergence of lateral roots, therefore inducing expansion of the root system. Surprisingly, root illumination also affects shoot development, including flowering time. Our analyses also show that root illumination alters the proper response to hormones or abiotic stress (e.g. salt or osmotic stress) and nutrient starvation, enhancing inhibition of root growth. In conclusion, D-Root provides a growing system closer to the natural one for assaying Arabidopsis plants, and therefore its use will contribute to a better understanding of the mechanisms involved in root development, hormonal signaling and stress responses. PMID:26312572

  12. Growth and development, and auxin polar transport in higher plants under microgravity conditions in space: BRIC-AUX on STS-95 space experiment.

    PubMed

    Ueda, J; Miyamoto, K; Yuda, T; Hoshino, T; Fujii, S; Mukai, C; Kamigaichi, S; Aizawa, S; Yoshizaki, I; Shimazu, T; Fukui, K

    1999-12-01

    The principal objectives of the space experiment, BRIC-AUX on STS 95, were the integrated analysis of the growth and development of etiolated pea and maize seedlings in space and a study of the effects of microgravity conditions in space on auxin polar transport in these segments. Microgravity significantly affected the growth and development of etiolated pea and maize seedlings. Epicotyls of etiolated pea seedlings were the most oriented toward about 40 to 60 degrees from the vertical. Mesocotyls of etiolated maize seedlings were curved at random during space flight but coleoptiles were almost straight. Finally the growth inhibition of these seedlings in space was also observed. Roots of some pea seedlings grew toward to the aerial space of Plant Growth Chamber. Extensibilities of cell walls of the third internode of etiolated pea epicotyls and the top region of etiolated maize coleoptiles, which were germinated and grown under microgravity conditions in space, were significantly low as compared with those grown on the ground of the earth. Activities of auxin polar transport in the second internode segments of etiolated pea seedlings and coleoptile segments of etiolated maize seedlings were significantly inhibited and promoted, respectively, under microgravity conditions in space. These results strongly suggest that auxin polar transport as well as the growth and development of plants is controlled under gravity on the earth.

  13. Contribution of arbuscular mycorrhizal fungi and/or bacteria to enhancing plant drought tolerance under natural soil conditions: effectiveness of autochthonous or allochthonous strains.

    PubMed

    Ortiz, N; Armada, E; Duque, E; Roldán, A; Azcón, R

    2015-02-01

    Autochthonous microorganisms [a consortium of arbuscular-mycorrhizal (AM) fungi and Bacillus thuringiensis (Bt)] were assayed and compared to Rhizophagus intraradices (Ri), Bacillus megaterium (Bm) or Pseudomonas putida (Psp) and non-inoculation on Trifolium repens in a natural arid soil under drought conditions. The autochthonous bacteria Bt and the allochthonous bacteria Psp increased nutrients and the relative water content and decreased stomatal conductance, electrolyte leakage, proline and APX activity, indicating their abilities to alleviate the drought stress. Mycorrhizal inoculation significantly enhanced plant growth, nutrient uptake and the relative water content, particularly when associated with specific bacteria minimizing drought stress-imposed effects. Specific combinations of autochthonous or allochthonous inoculants also contributed to plant drought tolerance by changing proline and antioxidative activities. However, non-inoculated plants had low relative water and nutrients contents, shoot proline accumulation and glutathione reductase activity, but the highest superoxide dismutase activity, stomatal conductance and electrolyte leakage. Microbial activities irrespective of the microbial origin seem to be coordinately functioning in the plant as an adaptive response to modulated water stress tolerance and minimizing the stress damage. The autochthonous AM fungi with Bt or Psp and those allochthonous Ri with Bm or Psp inoculants increased water stress alleviation. The autochthonous Bt showed the greatest ability to survive under high osmotic stress compared to the allochthonous strains, but when single inoculated or associated with Ri or AM fungi were similarly efficient in terms of physiological and nutritional status and in increasing plant drought tolerance, attenuating and compensating for the detrimental effect of water limitation.

  14. Contribution of arbuscular mycorrhizal fungi and/or bacteria to enhancing plant drought tolerance under natural soil conditions: effectiveness of autochthonous or allochthonous strains.

    PubMed

    Ortiz, N; Armada, E; Duque, E; Roldán, A; Azcón, R

    2015-02-01

    Autochthonous microorganisms [a consortium of arbuscular-mycorrhizal (AM) fungi and Bacillus thuringiensis (Bt)] were assayed and compared to Rhizophagus intraradices (Ri), Bacillus megaterium (Bm) or Pseudomonas putida (Psp) and non-inoculation on Trifolium repens in a natural arid soil under drought conditions. The autochthonous bacteria Bt and the allochthonous bacteria Psp increased nutrients and the relative water content and decreased stomatal conductance, electrolyte leakage, proline and APX activity, indicating their abilities to alleviate the drought stress. Mycorrhizal inoculation significantly enhanced plant growth, nutrient uptake and the relative water content, particularly when associated with specific bacteria minimizing drought stress-imposed effects. Specific combinations of autochthonous or allochthonous inoculants also contributed to plant drought tolerance by changing proline and antioxidative activities. However, non-inoculated plants had low relative water and nutrients contents, shoot proline accumulation and glutathione reductase activity, but the highest superoxide dismutase activity, stomatal conductance and electrolyte leakage. Microbial activities irrespective of the microbial origin seem to be coordinately functioning in the plant as an adaptive response to modulated water stress tolerance and minimizing the stress damage. The autochthonous AM fungi with Bt or Psp and those allochthonous Ri with Bm or Psp inoculants increased water stress alleviation. The autochthonous Bt showed the greatest ability to survive under high osmotic stress compared to the allochthonous strains, but when single inoculated or associated with Ri or AM fungi were similarly efficient in terms of physiological and nutritional status and in increasing plant drought tolerance, attenuating and compensating for the detrimental effect of water limitation. PMID:25462971

  15. Autochthonous arbuscular mycorrhizal fungi and Bacillus thuringiensis from a degraded Mediterranean area can be used to improve physiological traits and performance of a plant of agronomic interest under drought conditions.

    PubMed

    Armada, Elisabeth; Azcón, Rosario; López-Castillo, Olga M; Calvo-Polanco, Mónica; Ruiz-Lozano, Juan Manuel

    2015-05-01

    Studies have shown that some microorganisms autochthonous from stressful environments are beneficial when used with autochthonous plants, but these microorganisms rarely have been tested with allochthonous plants of agronomic interest. This study investigates the effectiveness of drought-adapted autochthonous microorganisms [Bacillus thuringiensis (Bt) and a consortium of arbuscular mycorrhizal (AM) fungi] from a degraded Mediterranean area to improve plant growth and physiology in Zea mays under drought stress. Maize plants were inoculated or not with B. thuringiensis, a consortium of AM fungi or a combination of both microorganisms. Plants were cultivated under well-watered conditions or subjected to drought stress. Several physiological parameters were measured, including among others, plant growth, photosynthetic efficiency, nutrients content, oxidative damage to lipids, accumulation of proline and antioxidant compounds, root hydraulic conductivity and the expression of plant aquaporin genes. Under drought conditions, the inoculation of Bt increased significantly the accumulation of nutrients. The combined inoculation of both microorganisms decreased the oxidative damage to lipids and accumulation of proline induced by drought. Several maize aquaporins able to transport water, CO2 and other compounds were regulated by the microbial inoculants. The impact of these microorganisms on plant drought tolerance was complementary, since Bt increased mainly plant nutrition and AM fungi were more active improving stress tolerance/homeostatic mechanisms, including regulation of plant aquaporins with several putative physiological functions. Thus, the use of autochthonous beneficial microorganisms from a degraded Mediterranean area is useful to protect not only native plants against drought, but also an agronomically important plant such as maize.

  16. An efficient method of propagation of Podophyllum hexandrum: an endangered medicinal plant of the Western Himalayas under ex situ conditions.

    PubMed

    Kharkwal, Amit C; Kushwaha, Rekha; Prakash, Om; Ogra, R K; Bhattacharya, Amita; Nagar, P K; Ahuja, Paramvir Singh

    2008-04-01

    This study shows an effective but simple method of conserving characterized populations and elite clones through vegetative propagation and genetic diversity through seeds in Podophyllum hexandrum (family Berberidaceae). Seed dormancy has been considered to be a major constraint in these seeds and most of the earlier reports recommended dormancy-breaking pretreatments such as chilling, gibberellic acid (GA(3)), etc. However, seeds of the 14 accessions that we tested exhibited no dormancy and hence did not require any pretreatments. Besides accession, collection of seeds with high moisture content could be one of the reasons for lack of dormancy. Thus, we propose germination of seeds (while they still retained moisture) in sand at 25 degrees C for high and reproducible results within a shorter period of time compared with earlier reports. Hypocotyl dormancy is known to considerably delay plant establishment and hence en masse propagation by preventing the emergence of functional leaves for up to 11-12 months. Manual removal of cotyledonary leaves, being labor and time intensive, is not a feasible method for large-scale seedling establishment. However, in this study, we showed that GA(3) at 200 ppm can alleviate hypocotyl dormancy besides reducing the time taken for true or functional leaf emergence. Treatment of cotyledonary leaves of 1 week-old-seedlings with 200 ppm GA(3 )resulted in true or functional leaf emergence within 7 days, and the resultant plants were also more vigorous than the ones obtained from manual removal of cotyledonary leaves. The study helped advance the establishment of seedlings by one growing season (almost 1 year).

  17. Chemical characterization of biogenic secondary organic aerosol generated from plant emissions under baseline and stressed conditions: inter- and intra-species variability for six coniferous species

    NASA Astrophysics Data System (ADS)

    Faiola, C. L.; Wen, M.; VanReken, T. M.

    2015-04-01

    The largest global source of secondary organic aerosol (SOA) in the atmosphere is derived from the oxidation of biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. Alterations to the biogenic volatile organic compound (BVOC) profile could impact the characteristics of the SOA formed from those emissions. This study investigated the impacts of one global change stressor, increased herbivory, on the composition of SOA derived from real plant emissions. Herbivory was simulated via application of methyl jasmonate (MeJA), a proxy compound. Experiments were repeated under pre- and post-treatment conditions for six different coniferous plant types. Volatile organic compounds (VOCs) emitted from the plants were oxidized to form SOA via dark ozone-initiated chemistry. The SOA chemical composition was measured using a Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS). The aerosol mass spectra of pre-treatment biogenic SOA from all plant types tended to be similar with correlations usually greater than or equal to 0.90. The presence of a stressor produced characteristic differences in the SOA mass spectra. Specifically, the following m/z were identified as a possible biogenic stress AMS marker with the corresponding HR ion(s) shown in parentheses: m/z 31 (CH3O+), m/z 58 (C2H2O2+, C3H6O+), m/z 29 (C2H5+), m/z 57 (C3H5O+), m/z 59 (C2H3O2+, C3H7O+), m/z 71 (C3H3O2+, C4H7O+), and m/z 83 (C5H7O+). The first aerosol mass spectrum of SOA generated from the oxidation of the plant stress hormone, MeJA, is also presented. Elemental analysis results demonstrated an O : C range of baseline biogenic SOA between 0.3 and 0.47. The O : C of standard MeJA SOA was 0.52. Results presented here could be used to help identify a biogenic plant stress marker in ambient data sets collected in forest environments.

  18. Chemical characterization of biogenic SOA generated from plant emissions under baseline and stressed conditions: inter- and intra-species variability for six coniferous species

    NASA Astrophysics Data System (ADS)

    Faiola, C. L.; Wen, M.; VanReken, T. M.

    2014-10-01

    The largest global source of secondary organic aerosol in the atmosphere is derived from the oxidation of biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. Alterations to the biogenic VOC profile could impact the characteristics of the SOA formed from those emissions. This study investigated the impacts of one global change stressor, increased herbivory, on the composition of SOA derived from real plant emissions. Herbivory was simulated via application of methyl jasmonate, a proxy compound. Experiments were repeated under pre- and post-treatment conditions for six different coniferous plant types. VOCs emitted from the plants were oxidized to form SOA via dark ozone-initiated chemistry. The SOA particle size distribution and chemical composition were measured using a scanning mobility particle sizer (SMPS) and Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS), respectively. The aerosol mass spectra of pre-treatment biogenic SOA from all plant types tended to be similar with correlations usually greater than or equal to 0.90. The presence of a stressor produced characteristic differences in the SOA mass spectra. Specifically, the following m/z were identified as a possible biogenic stress AMS marker with the corresponding HR ion(s) shown in parentheses: m/z 31 (CH3O+), m/z 58 (C2H2O2+, C3H6O+) m/z 29 (C2H5+), m/z 57 (C3H5O+), m/z 59 (C2H3O2+, C3H7O+), m/z 71 (C3H3O2+, C4H7O+), and m/z 83 (C5H7O+). The first aerosol mass spectrum of SOA generated from the oxidation of the plant stress hormone, methyl jasmonate, is also presented. Elemental analysis results demonstrated an O:C range of baseline biogenic SOA between 0.3-0.47. The O:C of standard methyl jasmonate SOA was 0.52. Results presented here could be used to help identify a biogenic plant stress marker in ambient datasets collected in forest environments.

  19. Chemical characterization of biogenic secondary organic aerosol generated from plant emissions under baseline and stressed conditions: inter- and intra-species variability for six coniferous species

    DOE PAGES

    Faiola, C. L.; Wen, M.; VanReken, T. M.

    2015-04-01

    The largest global source of secondary organic aerosol (SOA) in the atmosphere is derived from the oxidation of biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. Alterations to the biogenic volatile organic compound (BVOC) profile could impact the characteristics of the SOA formed from those emissions. This study investigated the impacts of one global change stressor, increased herbivory, on the composition of SOA derived from real plant emissions. Herbivory was simulated via application of methyl jasmonate (MeJA), a proxy compound. Experiments were repeated under pre- andmore » post-treatment conditions for six different coniferous plant types. Volatile organic compounds (VOCs) emitted from the plants were oxidized to form SOA via dark ozone-initiated chemistry. The SOA chemical composition was measured using a Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS). The aerosol mass spectra of pre-treatment biogenic SOA from all plant types tended to be similar with correlations usually greater than or equal to 0.90. The presence of a stressor produced characteristic differences in the SOA mass spectra. Specifically, the following m/z were identified as a possible biogenic stress AMS marker with the corresponding HR ion(s) shown in parentheses: m/z 31 (CH3O+), m/z 58 (C2H2O2+, C3H6O+), m/z 29 (C2H5+), m/z 57 (C3H5O+), m/z 59 (C2H3O2+, C3H7O+), m/z 71 (C3H3O2+, C4H7O+), and m/z 83 (C5H7O+). The first aerosol mass spectrum of SOA generated from the oxidation of the plant stress hormone, MeJA, is also presented. Elemental analysis results demonstrated an O : C range of baseline biogenic SOA between 0.3 and 0.47. The O : C of standard MeJA SOA was 0.52. Results presented here could be used to help identify a biogenic plant stress marker in ambient data sets collected in forest environments.« less

  20. Chemical characterization of biogenic SOA generated from plant emissions under baseline and stressed conditions: inter- and intra-species variability for six coniferous species

    DOE PAGES

    Faiola, C. L.; Wen, M.; VanReken, T. M.

    2014-10-01

    The largest global source of secondary organic aerosol in the atmosphere is derived from the oxidation of biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. Alterations to the biogenic VOC profile could impact the characteristics of the SOA formed from those emissions. This study investigated the impacts of one global change stressor, increased herbivory, on the composition of SOA derived from real plant emissions. Herbivory was simulated via application of methyl jasmonate, a proxy compound. Experiments were repeated under pre- and post-treatment conditions for six differentmore » coniferous plant types. VOCs emitted from the plants were oxidized to form SOA via dark ozone-initiated chemistry. The SOA particle size distribution and chemical composition were measured using a scanning mobility particle sizer (SMPS) and Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS), respectively. The aerosol mass spectra of pre-treatment biogenic SOA from all plant types tended to be similar with correlations usually greater than or equal to 0.90. The presence of a stressor produced characteristic differences in the SOA mass spectra. Specifically, the following m/z were identified as a possible biogenic stress AMS marker with the corresponding HR ion(s) shown in parentheses: m/z 31 (CH3O+), m/z 58 (C2H2O2+, C3H6O+) m/z 29 (C2H5+), m/z 57 (C3H5O+), m/z 59 (C2H3O2+, C3H7O+), m/z 71 (C3H3O2+, C4H7O+), and m/z 83 (C5H7O+). The first aerosol mass spectrum of SOA generated from the oxidation of the plant stress hormone, methyl jasmonate, is also presented. Elemental analysis results demonstrated an O:C range of baseline biogenic SOA between 0.3–0.47. The O:C of standard methyl jasmonate SOA was 0.52. Results presented here could be used to help identify a biogenic plant stress marker in ambient datasets collected in forest environments.« less

  1. Consequences of Predicted or Actual Asteroid Impacts

    NASA Astrophysics Data System (ADS)

    Chapman, C. R.

    2003-12-01

    Earth impact by an asteroid could have enormous physical and environmental consequences. Impactors larger than 2 km diameter could be so destructive as to threaten civilization. Since such events greatly exceed any other natural or man-made catastrophe, much extrapolation is necessary just to understand environmental implications (e.g. sudden global cooling, tsunami magnitude, toxic effects). Responses of vital elements of the ecosystem (e.g. agriculture) and of human society to such an impact are conjectural. For instance, response to the Blackout of 2003 was restrained, but response to 9/11 terrorism was arguably exaggerated and dysfunctional; would society be fragile or robust in the face of global catastrophe? Even small impacts, or predictions of impacts (accurate or faulty), could generate disproportionate responses, especially if news media reports are hyped or inaccurate or if responsible entities (e.g. military organizations in regions of conflict) are inadequately aware of the phenomenology of small impacts. Asteroid impact is the one geophysical hazard of high potential consequence with which we, fortunately, have essentially no historical experience. It is thus important that decision makers familiarize themselves with the hazard and that society (perhaps using a formal procedure, like a National Academy of Sciences study) evaluate the priority of addressing the hazard by (a) further telescopic searches for dangerous but still-undiscovered asteroids and (b) development of mitigation strategies (including deflection of an oncoming asteroid and on- Earth civil defense). I exemplify these issues by discussing several representative cases that span the range of parameters. Many of the specific physical consequences of impact involve effects like those of other geophysical disasters (flood, fire, earthquake, etc.), but the psychological and sociological aspects of predicted and actual impacts are distinctive. Standard economic cost/benefit analyses may not

  2. [Glass fibre HEPA filters. II. Communication: Microbiological and physico-chemical researchs on used and unusued, hydrophilic and hydrophobic filter materials in an air conditioning plant (author's transl)].

    PubMed

    Rüden, H; Mihm, U; Schoemann, D; Botzenhart, K; Thofern, E

    1975-07-01

    Hydrophobic and hydrophilic, used and unused HEPA filters from various manufacturers, inoculated with vegetative bacteria, bacterial and fungal spores, were exposed to clean outside air for up to 17 weeks in an air conditioning plant. With relative humidities up to 60%, an increase in germ count could not be found. The rate of killing the micro-organisms inoculated were different and were generally higher on used filters. The low water content of the filter material was apparently not sufficient for microbial growth. In addition, the increase in electric conductivity and reduction of pH value resulting from deposition of substances from the outside air with an acid reaction ascertained in the aqueous filter extracts had a negative effect on the living conditions of the microorganisms.

  3. PII Overexpression in Lotus japonicus Affects Nodule Activity in Permissive Low-Nitrogen Conditions and Increases Nodule Numbers in High Nitrogen Treated Plants.

    PubMed

    D'Apuzzo, Enrica; Valkov, Vladimir Totev; Parlati, Aurora; Omrane, Selim; Barbulova, Ani; Sainz, Maria Martha; Lentini, Marco; Esposito, Sergio; Rogato, Alessandra; Chiurazzi, Maurizio

    2015-04-01

    We report here the first characterization of a GLNB1 gene coding for the PII protein in leguminous plants. The main purpose of this work was the investigation of the possible roles played by this multifunctional protein in nodulation pathways. The Lotus japonicus LjGLB1 gene shows a significant transcriptional regulation during the light-dark cycle and different nitrogen availability, conditions that strongly affect nodule formation, development, and functioning. We also report analysis of the spatial profile of expression of LjGLB1 in root and nodule tissues and of the protein's subcellular localization. Transgenic L. japonicus lines overexpressing the PII protein were obtained and tested for the analysis of the symbiotic responses in different conditions. The uncoupling of PII from its native regulation affects nitrogenase activity and nodule polyamine content. Furthermore, our results suggest the involvement of PII in the signaling of the nitrogen nutritional status affecting the legumes' predisposition for nodule formation.

  4. Influence of operating conditions for volatile fatty acids enrichment as a first step for polyhydroxyalkanoate production on a municipal waste water treatment plant.

    PubMed

    Pittmann, Timo; Steinmetz, Heidrun

    2013-11-01

    This work describes the generation of volatile fatty acids (VFAs) as the first step of the polyhydroxyalkanoate (PHA) production cycle. Therefore four different substrates from a municipal waste water treatment plant (WWTP) were investigated regarding high VFA production and stable VFA composition. Due to its highest VFA yield primary sludge was used as substrate to test a series of operating conditions (temperature, pH, retention time (RT) and withdrawal (WD)) in order to find suitable conditions for a stable VFA production. The results demonstrated that although the substrate primary sludge differs in its consistence a stable composition of VFA could be achieved. Experiments with a semi-continuous reactor operation showed that a short RT of 4d and a small WD of 25% at pH=6 and around 30°C is preferable for high VFA mass flow (MF=1913 mg VFA/(Ld)) and a stable VFA composition.

  5. Potential use of presumptive enterococci and staphylococci as indicators of sanitary condition in plants making hard Italian-type cheese.

    PubMed

    Ingham, S C; Reyes, J C; Schoeller, N P; Lang, M M

    2000-12-01

    Raw milk, pasteurized milk, unripened cheese (1 day old), and partially ripened cheese (3 months) from 42 milk lots at a plant making hard Italian-type cheese were analyzed for presumptive enterococci using kanamycin esculin azide agar pour plates. Fully ripened (> or =10 months) cheeses, derived from other milk lots, were also tested. Numbers of presumptive staphylococci (Baird-Parker agar [B-P]) were determined in the partially and fully ripened cheeses. Presumptive enterococci were ubiquitous in raw milk, usually at levels of 2.1 to 3.0 log CFU/ml. Enterococci were detected in 11 (26%) of 42 pasteurized milk samples. Enterococci and staphylococci were detected in 39 (93%) and 6 (14%) of unripened cheeses and in 33 (80%) and 4 (10%) of partially ripened cheeses, respectively. Only eight and five samples of enterococci-positive unripened and partially ripened cheese, respectively, were made from pasteurized milk in which presumptive enterococci were detected. Of 42 samples of fully ripened cheese, 35 (83%) and 8 (19%), respectively, contained presumptive enterococci and staphylococci. Results suggest either that low numbers of presumptive enterococci survive pasteurization and cheese ripening or that contamination of cheese by enterococci occurs after pasteurization. Biochemical testing confirmed 63% of presumptive enterococci isolates. None of the 20 presumptive staphylococci isolates produced colonies typical of Staphylococcus aureus on B-P agar; the isolates were identified as 1 Staphylococcus epidermidis, 1 Staphylococcus xylosus, 2 Staphylococcus saprophyticus, 1 Staphylococcus warneri, 5 Kocuria spp., and 10 unidentified gram-positive, catalase-positive cocci. Three staphylococci isolates decreased in numbers by more than 3.0 log CFU/ml in 9.9 ml of skim milk heated 30 min in a 62.8 degrees C water bath. This finding suggests that most presumptive staphylococci detected may have been prepasteurization contaminants. Unless specificity of the kanamycin esculin

  6. Uniformity of environmental conditions and plant growth in a hydroponic culture system for use in a growth room with aerial CO2 control

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; York, E. K.; Henry, L. T.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1988-01-01

    A portable system of hydroponic culture was developed that maintained temperature, pH, and nutrient concentrations of circulating nutrient solutions. The hydroponic system is used within a controlled-environment room (CER) for control of aerial environment. The CER was equipped with an auto-calibrating system for atmospheric CO2 control. The control systems for the hydroponic chambers were able to maintain acidity within +/- 0.2 pH units and the temperature with +/- 0.5 degree C. Mixing time for the 200-liter volume of solution within a hydroponic chamber was less than 12 min. The CO2 control system was able to maintain aerial concentrations within +/- 10 ppm CO2 during the light period. The only gradient found to occur within the hydroponic chambers or CER was a slight gradient in aerial temperature along the length of hydroponic chambers. Growth of soybeans [Glycine max (L.) Merr.] was characterized during a 3-week period of vegetative development by leaf number and area, plant dry weight, total N content of plants, and N depletion from the nutrient solution. The growth characteristics among populations for three hydroponic chambers within the CER were not significantly different, and the percent standard errors of means of the measurements within populations from each chamber were nearly all less than 10%. Thus, the uniformity of plant growth reflected the uniformity of environmental conditions.

  7. Influence of habitat and climate variables on arbuscular mycorrhizal fungus community distribution, as revealed by a case study of facultative plant epiphytism under semiarid conditions.

    PubMed

    Torrecillas, E; Torres, P; Alguacil, M M; Querejeta, J I; Roldán, A

    2013-12-01

    In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats.

  8. Influence of Habitat and Climate Variables on Arbuscular Mycorrhizal Fungus Community Distribution, as Revealed by a Case Study of Facultative Plant Epiphytism under Semiarid Conditions

    PubMed Central

    Torrecillas, E.; Torres, P.; Querejeta, J. I.; Roldán, A.

    2013-01-01

    In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats. PMID:24038687

  9. The use of a halophytic plant species and organic amendments for the remediation of a trace elements-contaminated soil under semi-arid conditions.

    PubMed

    Clemente, Rafael; Walker, David J; Pardo, Tania; Martínez-Fernández, Domingo; Bernal, M Pilar

    2012-07-15

    The halophytic shrub Atriplex halimus L. was used in a field phytoremediation experiment in a semi-arid area highly contaminated by trace elements (As, Cd, Cu, Mn, Pb and Zn) within the Sierra Minera of La Unión-Cartagena (SE Spain). The effects of compost and pig slurry on soil conditions and plant growth were determined. The amendments (particularly compost) only slightly affected trace element concentrations in soil pore water or their availability to the plants, increased soil nutrient and organic matter levels and favoured the development of a sustainable soil microbial biomass (effects that were enhanced by the presence of A. halimus) as well as, especially for slurry, increasing A. halimus biomass and ground cover. With regard to the minimisation of trace elements concentrations in the above-ground plant parts, the effectiveness of both amendments was greatest 12-16 months after their incorporation. The findings demonstrate the potential of A. halimus, particularly in combination with an organic amendment, for the challenging task of the phytostabilisation of contaminated soils in (semi-)arid areas and suggest the need for an ecotoxicological evaluation of the remediated soils. However, the ability of A. halimus to accumulate Zn and Cd in the shoot may limit its use to moderately-contaminated sites.

  10. Uranium immobilization in an iron-rich rhizosphere of a native wetland plant from the Savannah River Site under reducing conditions.

    PubMed

    Chang, Hyun-shik; Buettner, Shea W; Seaman, John C; Jaffé, Peter R; van Groos, Paul G Koster; Li, Dien; Peacock, Aaron D; Scheckel, Kirk G; Kaplan, Daniel I

    2014-08-19

    The hypothesis of this study was that iron plaques formed on the roots of wetland plants and their rhizospheres create environmental conditions favorable for iron reducing bacteria that promote the in situ immobilization of uranium. Greenhouse microcosm studies were conducted using native plants (Sparganium americanum) from a wetland located on the Savannah River Site, Aiken, SC. After iron plaques were established during a 73-day period by using an anoxic Fe(II)-rich nutrient solution, a U(VI) amended nutrient solution was added to the system for an additional two months. Compared to plant-free control microcosms, microcosms containing iron plaques successfully stimulated the growth of targeted iron reducing bacteria, Geobacter spp. Their population continuously increased after the introduction of the U(VI) nutrient solution. The reduction of some of the U(VI) to U(IV) by iron reducing bacteria was deduced based on the observations that the aqueous Fe(II) concentrations increased while the U(VI) concentrations decreased. The Fe(II) produced by the iron reducing bacteria was assumed to be reoxidized by the oxygen released from the roots. Advanced spectroscopic analyses revealed that a significant fraction of the U(VI) had been reduced to U(IV) and they were commonly deposited in association with phosphorus on the iron plaque.

  11. The use of a halophytic plant species and organic amendments for the remediation of a trace elements-contaminated soil under semi-arid conditions.

    PubMed

    Clemente, Rafael; Walker, David J; Pardo, Tania; Martínez-Fernández, Domingo; Bernal, M Pilar

    2012-07-15

    The halophytic shrub Atriplex halimus L. was used in a field phytoremediation experiment in a semi-arid area highly contaminated by trace elements (As, Cd, Cu, Mn, Pb and Zn) within the Sierra Minera of La Unión-Cartagena (SE Spain). The effects of compost and pig slurry on soil conditions and plant growth were determined. The amendments (particularly compost) only slightly affected trace element concentrations in soil pore water or their availability to the plants, increased soil nutrient and organic matter levels and favoured the development of a sustainable soil microbial biomass (effects that were enhanced by the presence of A. halimus) as well as, especially for slurry, increasing A. halimus biomass and ground cover. With regard to the minimisation of trace elements concentrations in the above-ground plant parts, the effectiveness of both amendments was greatest 12-16 months after their incorporation. The findings demonstrate the potential of A. halimus, particularly in combination with an organic amendment, for the challenging task of the phytostabilisation of contaminated soils in (semi-)arid areas and suggest the need for an ecotoxicological evaluation of the remediated soils. However, the ability of A. halimus to accumulate Zn and Cd in the shoot may limit its use to moderately-contaminated sites. PMID:22595543

  12. Influence of habitat and climate variables on arbuscular mycorrhizal fungus community distribution, as revealed by a case study of facultative plant epiphytism under semiarid conditions.

    PubMed

    Torrecillas, E; Torres, P; Alguacil, M M; Querejeta, J I; Roldán, A

    2013-12-01

    In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats. PMID:24038687

  13. Using Mesoscale Weather Model Output as Boundary Conditions for Atmospheric Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)

    SciTech Connect

    Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.

    2013-10-01

    Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale atmospheric large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.

  14. Relative Importance of Current and Past Landscape Structure and Local Habitat Conditions for Plant Species Richness in Dry Grassland-Like Forest Openings

    PubMed Central

    Husáková, Iveta; Münzbergová, Zuzana

    2014-01-01

    In fragmented landscapes, plant species richness may depend not only on local habitat conditions but also on landscape structure. In addition, both present and past landscape structure may be important for species richness. There are, however, only a few studies that have investigated the relative importance of all of these factors. The aim of this study was to examine the effect of current and past landscape structures and habitat conditions on species richness at dry grassland-like forest openings in a forested landscape and to assess their relative importance for species richness. We analyzed information on past and present landscape structures using aerial photographs from 1938, 1973, 1988, 2000 and 2007. We calculated the area of each locality and its isolation in the present and in the past and the continuity of localities in GIS. At each locality, we recorded all vascular plant species (296 species in 110 forest openings) and information on abiotic conditions of the localities. We found that the current species richness of the forest openings was significantly determined by local habitat conditions as well as by landscape structure in the present and in the past. The highest species richness was observed on larger and more heterogeneous localities with rocks and shallow soils, which were already large and well connected to other localities in 1938. The changes in the landscape structure in the past can thus have strong effects on current species richness. Future studies attempting to understand determinants of species diversity in fragmented landscapes should also include data on past landscape structure, as it may in fact be more important than the present structure. PMID:24809474

  15. Relative importance of current and past landscape structure and local habitat conditions for plant species richness in dry grassland-like forest openings.

    PubMed

    Husáková, Iveta; Münzbergová, Zuzana

    2014-01-01

    In fragmented landscapes, plant species richness may depend not only on local habitat conditions but also on landscape structure. In addition, both present and past landscape structure may be important for species richness. There are, however, only a few studies that have investigated the relative importance of all of these factors. The aim of this study was to examine the effect of current and past landscape structures and habitat conditions on species richness at dry grassland-like forest openings in a forested landscape and to assess their relative importance for species richness. We analyzed information on past and present landscape structures using aerial photographs from 1938, 1973, 1988, 2000 and 2007. We calculated the area of each locality and its isolation in the present and in the past and the continuity of localities in GIS. At each locality, we recorded all vascular plant species (296 species in 110 forest openings) and information on abiotic conditions of the localities. We found that the current species richness of the forest openings was significantly determined by local habitat conditions as well as by landscape structure in the present and in the past. The highest species richness was observed on larger and more heterogeneous localities with rocks and shallow soils, which were already large and well connected to other localities in 1938. The changes in the landscape structure in the past can thus have strong effects on current species richness. Future studies attempting to understand determinants of species diversity in fragmented landscapes should also include data on past landscape structure, as it may in fact be more important than the present structure.

  16. [Genetic base of Arabidopsis thaliana (L.) Heynh: fitness of plants for extreme conditions in northern margins of species range].

    PubMed

    Kurbidaeva, A S; Zaretskaia, M V; Soltabaeva, A D; Novokreshchenova, M G; Kupriianova, E V; Fedorenko, O M; Ezhova, T A

    2013-08-01

    Flowering time and vernalization requirement were studied in eight natural Karelian populations (KPs) of Arabidopsis thaliana. These KPs consisted of late-flowering plants with elevated expression of flowering repressor FLC and a reduced expression level of flowering activator SOC1 compared to the early-flowering ecotypes Dijon-M and Cvi-0. Despite variations in flowering time and the vernalization requirement among the KPs, two-week-old seedlings showed no changes in either the nucleotide sequence of the FRI gene or the relative expression levels of FRI and its target gene FLC that would be responsible for this variation. An analysis of abscisic acid (ABA) biosynthesis and catabolism genes (NCED3 and CYP707A2) did not show significant differences between late-flowering KPs and the early-flowering ecotypes Dijon-M and Cvi-0. Cold treatment (4 degrees C for 24 h) induced the expression of not only NCED3, but also RD29B, a gene involved in the ABA-dependent cold-response pathway. The relative levels of cold activation of these genes were nearly equal in all genotypes under study. Thus, the ABA-dependent cold response pathway does not depend on FLC expression. The lack of significant differences between northern populations, as well as the ecotypes Dijon-M (Europe) and Cvi-0 (Cape Verde Islands), indicates that this pathway is not crucial for fitness to the northern environment. PMID:25474881

  17. [Genetic base of Arabidopsis thaliana (L.) Heynh: fitness of plants for extreme conditions in northern margins of species range].

    PubMed

    2013-08-01

    Flowering time and vernalization requirement were studied in eight natural Karelian populations (KPs) of Arabidopsis thaliana. These KPs consisted of late-flowering plants with elevated expression of flowering repressor FLC and a reduced expression level of flowering activator SOC1 compared to the early-flowering ecotypes Dijon-M and Cvi-0. Despite variations in flowering time and the vernalization requirement among the KPs, two-week-old seedlings showed no changes in either the nucleotide sequence of the FRI gene or the relative expression levels of FRI and its target gene FLC that would be responsible for this variation. An analysis of abscisic acid (ABA) biosynthesis and catabolism genes (NCED3 and CYP707A2) did not show significant differences between late-flowering KPs and the early-flowering ecotypes Dijon-M and Cvi-0. Cold treatment (4 degrees C for 24 h) induced the expression of not only NCED3, but also RD29B, a gene involved in the ABA-dependent cold-response pathway. The relative levels of cold activation of these genes were nearly equal in all genotypes under study. Thus, the ABA-dependent cold response pathway does not depend on FLC expression. The lack of significant differences between northern populations, as well as the ecotypes Dijon-M (Europe) and Cvi-0 (Cape Verde Islands), indicates that this pathway is not crucial for fitness to the northern environment. PMID:25508660

  18. Power conditioning subsystems for photovoltaic central-station power plants - State-of-the-art and advanced technology

    NASA Technical Reports Server (NTRS)

    Bulawka, A.; Krauthamer, S.; Das, R.

    1986-01-01

    An overview is given of the technical and near-term cost requirements that must be met to develop economically viable power conditioning subsystems (PCS) for large-scale, central photovoltaic power stations. Various commercially available PCS hardware suitable for use in today's central photovoltaic power stations are also surveyed. Federal and industrial activities in the research and development of advanced PCSs that will contribute to the attainment of fully competitive, large-scale photovoltaic power stations are reviewed. The status of the DOE central station PCS program is discussed.

  19. Land use and habitat conditions across the southwestern Wyoming sagebrush steppe: development impacts, management effectiveness and the distribution of invasive plants

    USGS Publications Warehouse

    Manier, Daniel J.; Aldridge, Cameron L.; Anderson, Patrick; Chong, Geneva; Homer, Collin G.; O'Donnell, Michael S.; Schell, Spencer

    2011-01-01

    For the past several years, USGS has taken a multi-faceted approach to investigating the condition and trends in sagebrush steppe ecosystems. This recent effort builds upon decades of work in semi-arid ecosystems providing a specific, applied focus on the cumulative impacts of expanding human activities across these landscapes. Here, we discuss several on-going projects contributing to these efforts: (1) mapping and monitoring the distribution and condition of shrub steppe communities with local detail at a regional scale, (2) assessing the relationships between specific, land-use features (for example, roads, transmission lines, industrial pads) and invasive plants, including their potential (environmentally defined) distribution across the region, and (3) monitoring the effects of habitat treatments on the ecosystem, including wildlife use and invasive plant abundance. This research is focused on the northern sagebrush steppe, primarily in Wyoming, but also extending into Montana, Colorado, Utah and Idaho. The study area includes a range of sagebrush types (including, Artemisia tridentata ssp. tridentata, Artemisia tridentata ssp. wyomingensis, Artemisia tridentata ssp. vaseyana, Artemisia nova) and other semi-arid shrubland types (for example, Sarcobatus vermiculatus, Atriplex confertifolia, Atriplex gardneri), impacted by extensive interface between steppe ecosystems and industrial energy activities resulting in a revealing multiple-variable analysis. We use a combination of remote sensing (AWiFS (1 Any reference to platforms, data sources, equipment, software, patented or trade-marked methods is for information purposes only. It does not represent endorsement of the U.S.D.I., U.S.G.S. or the authors), Landsat and Quickbird platforms), Geographic Information System (GIS) design and data management, and field-based, replicated sampling to generate multiple scales of data representing the distribution of shrub communities for the habitat inventory. Invasive plant

  20. Effects of plant growth promoting bacteria and mycorrhizal on Capsicum annuum L. var. aviculare ([Dierbach] D'Arcy and Eshbaugh) germination under stressing abiotic conditions.

    PubMed

    Rueda-Puente, Edgar Omar; Murillo-Amador, Bernardo; Castellanos-Cervantes, T; García-Hernández, José Luís; Tarazòn-Herrera, Mario Antonio; Moreno Medina, Salomòn; Gerlach Barrera, Luis Ernesto

    2010-08-01

    Capsicum annuum var. aviculare to Tarahumara and Papago Indians and farmers of Sonora desert is a promising biological and commercial value as a natural resource from arid and semiarid coastal zones. Traditionally, apply synthetic fertilizers to compensate for soil nitrogen deficiency. However, indiscriminate use of these fertilizers might increase salinity. The inoculation by plant growth promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) represents an alternative as potential bio fertilizer resources for salty areas. Seeds ecotypes from four areas of Sonora desert (Mazocahui, Baviacora, Arizpe, La Tortuga), in order to inoculate them with one species of PGPB and AMF. Two germination tests were carried out to study the effect of salinity, temperature regime (night/day) and inoculation with PGPB and AMF growth factors measured on germination (percentage and rate), plant height, root length, and produced biomass (fresh and dry matter). The results indicated that from four studied ecotypes, Mazocahui was the most outstanding of all, showing the highest germination under saline and non-saline conditions. However, the PGPB and AMF influenced the others variables evaluated. This study is the first step to obtain an ideal ecotype of C. a. var. aviculare, which grows in the northwest of México and promoting this type of microorganisms as an efficient and reliable biological product. Studies of the association of PGPB and AMF with the C. a. var. aviculare-Mazocahui ecotype are recommended to determine the extent to which these observations can be reproduced under field conditions.

  1. Effects of plant growth promoting bacteria and mycorrhizal on Capsicum annuum L. var. aviculare ([Dierbach] D'Arcy and Eshbaugh) germination under stressing abiotic conditions.

    PubMed

    Rueda-Puente, Edgar Omar; Murillo-Amador, Bernardo; Castellanos-Cervantes, T; García-Hernández, José Luís; Tarazòn-Herrera, Mario Antonio; Moreno Medina, Salomòn; Gerlach Barrera, Luis Ernesto

    2010-08-01

    Capsicum annuum var. aviculare to Tarahumara and Papago Indians and farmers of Sonora desert is a promising biological and commercial value as a natural resource from arid and semiarid coastal zones. Traditionally, apply synthetic fertilizers to compensate for soil nitrogen deficiency. However, indiscriminate use of these fertilizers might increase salinity. The inoculation by plant growth promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) represents an alternative as potential bio fertilizer resources for salty areas. Seeds ecotypes from four areas of Sonora desert (Mazocahui, Baviacora, Arizpe, La Tortuga), in order to inoculate them with one species of PGPB and AMF. Two germination tests were carried out to study the effect of salinity, temperature regime (night/day) and inoculation with PGPB and AMF growth factors measured on germination (percentage and rate), plant height, root length, and produced biomass (fresh and dry matter). The results indicated that from four studied ecotypes, Mazocahui was the most outstanding of all, showing the highest germination under saline and non-saline conditions. However, the PGPB and AMF influenced the others variables evaluated. This study is the first step to obtain an ideal ecotype of C. a. var. aviculare, which grows in the northwest of México and promoting this type of microorganisms as an efficient and reliable biological product. Studies of the association of PGPB and AMF with the C. a. var. aviculare-Mazocahui ecotype are recommended to determine the extent to which these observations can be reproduced under field conditions. PMID:20447830

  2. Mathematical simulation of the operating emergency conditions for the purpose of energy efficiency increase of thermal power plants management

    NASA Astrophysics Data System (ADS)

    Gazizova, O. V.; Malafeyev, A. V.; Kondrashova, Y. N.

    2016-04-01

    The regulations of the energy saving policy, being implemented at present, require an enhanced reliability of the power supply systems and operations of the motive loading, actuating machines and mechanisms, for the purpose of reduction of power inputs under operating emergency conditions. The development of industrial units of the distributed generation enables putting the generators, equipped with motors of the comparable power, into the operation, which is non-parallel to a power system. To provide static stability under such conditions the complex approach is required since it allows estimating the stability of the generators and the load during parallel and non-parallel operations with the power system and a complex circuit configuration. The mathematical models of units of the distributed generation and motive loading considering the character of the given mechanism are developed. They are implemented in the software package allowing the operative-dispatch personnel of the industrial power stations to forecast similar modes and develop special measures to provide a stable operation of electrical machines.

  3. Real-time condition monitoring of thermal power plants feed-pumps by rolling bearings supports vibration

    NASA Astrophysics Data System (ADS)

    Kostyukov, V. N.; Tarasov, E. V.

    2012-05-01

    The report addresses the real-time condition monitoring of technical state and automatic diagnosis of auxiliary equipment for bearings supports vibration, for example, control of the feed-pump operating modes of thermal power stations. The causes that lead to premature birth and development of defects in rolling bearings are identified and the development of activities ensuring safe and continuous operation of the auxiliary equipment of thermal power stations is carried out. Collection and analysis of vibration parameters of pumping units during their operation at the operating modes of the technological process are realized by means of real-time technical condition monitoring. Spectral analysis of vibration parameters of one of the pumps showed the presence of frequency components, which mark violations in the operating practices of the pump, the imbalance development and, as a consequence, the development of defects in the bearings by long-term operation of the unit. Timely warning of the personnel on the operation of the unit with the "INTOLERABLE" technical state and automatic warning issuance of the need to change the technological process allowed to recover the estimated pump operation mode in due time and prevent further development of defects in equipment.

  4. Impact of the addition of different plant residues on nitrogen mineralization-immobilization turnover and carbon content of a soil incubated under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kaleeem Abbasi, M.; Tahir, M. Mahmood; Sabir, N.; Khurshid, M.

    2015-02-01

    Application of plant residues as soil amendment may represent a valuable recycling strategy that affects carbon (C) and nitrogen (N) cycling in soil-plant systems. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water-filled pore space) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues, i.e., the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Populus euramericana, Robinia pseudoacacia and Elaeagnus umbellata, incorporated into the soil at the rate of 200 mg residue N kg-1 soil. The diverse plant residues showed a wide variation in total N, C, lignin, polyphenols and C / N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of Glycine max and the shoot and root of Trifolium repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg-1 and representing a 55, 37 and 36% recovery of N that had been released from these added resources. The roots of Glycine max and Zea mays and the shoot of Zea mays showed continuous negative values throughout the incubation. After an initial immobilization, leaves of Populus euramericana, Robinia pseudoacacia and Elaeagnus umbellata exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg-1, respectively, and representing a 16, 32 and 33% N recovery, respectively. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01) and negatively correlated with lignin content (r = -0.84; p ≤ 0.01), C / N ratio (r = -0.69; p ≤ 0.05), lignin / N ratio (r = -0.68; p ≤ 0.05), polyphenol / N ratio (r = -0.73; p ≤ 0.05) and (lignin + polyphenol) : N ratio (r = -0.70; p ≤ 0.05) indicating a

  5. Impact of the addition of different plant residues on carbon-nitrogen content and nitrogen mineralization-immobilization turnover in a soil incubated under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Abbasi, M. K.; Tahir, M. M.; Sabir, N.; Khurshid, M.

    2014-10-01

    Application of plant residues as soil amendment may represent a valuable recycling strategy that affects on carbon (C) and nitrogen (N) cycling, soil properties improvement and plant growth promotion. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water filled pore space (WFPS)) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues i.e. the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Poplus euramericana, Rubinia pseudoacacia and Elagnus umbellate incorporated into the soil at the rate of 200 mg residue N kg-1 soil. The diverse plant residues showed wide variation in total N, carbon, lignin, polyphenols and C/N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of G. max and the shoot and root of T. repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg-1 and representing a 55, 37 and 36% of added N being released from these resources. The roots of G. max and Z. mays and the shoot of Z. mays showed continuous negative values throughout the incubation showing net immobilization. After an initial immobilization, leaves of P. euramericana, R. pseudoacacia and E. umbellate exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg-1, respectively and representing a 16, 32 and 33% of added N being released. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01), and negatively correlated with lignin content (r = -0.84; p ≤ 0.01), C/N ratio (r = -0.69; p ≤ 0.05), lignin/N ratio (r = -0.68; p ≤ 0.05), polyphenol/N ratio (r = -0.73; p ≤ 0.05) and ligin + polyphenol/N ratio (r = -0.70; p ≤ 0.05) indicating

  6. AMT1;1 transgenic rice plants with enhanced NH4(+) permeability show superior growth and higher yield under optimal and suboptimal NH4(+) conditions.

    PubMed

    Ranathunge, Kosala; El-Kereamy, Ashraf; Gidda, Satinder; Bi, Yong-Mei; Rothstein, Steven J

    2014-03-01

    The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4(+)). The NH4(+) uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4(+) transport in rice plants. However, little is known about its involvement in NH4(+) uptake in rice roots and subsequent effects on NH4(+) assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4(+) permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4(+) content in the shoots and roots than the WT. Direct NH4(+) fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4(+) contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4(+) levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions.

  7. Effects of selenite and selenate application on growth and shoot selenium accumulation of pak choi (Brassica chinensis L.) during successive planting conditions.

    PubMed

    Li, Jun; Liang, Dongli; Qin, Siyue; Feng, Puyang; Wu, Xiongping

    2015-07-01

    Selenate and selenite are two main kinds of inorganic selenium (Se) sources in soil, but these substances can pose threats to the environment. Phytoextraction is an emerging technology to remove Se from polluted soils by using a hyper-accumulator. In this study, a pot experiment was conducted to investigate Se phytoextraction potential of pak choi (Brassica chinensis L.) and to determine the effects of Se on growth and Se accumulation of pak choi under successive planting conditions (four crops). Results showed that Se concentration in pak choi shoots significantly increased as selenate and selenite rates increased. Se concentration increased in successive crops on soil treated with selenite; by contrast, Se concentration decreased in crops on soil treated with selenate. Se concentrations of pak choi on soil treated with selenate were higher than those on soil treated with selenite. The maximum Se accumulations amount in crops on selenite