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Sample records for germination test applied

  1. Germination and root elongation bioassays in six different plant species for testing Ni contamination in soil.

    PubMed

    Visioli, Giovanna; Conti, Federica D; Gardi, Ciro; Menta, Cristina

    2014-04-01

    In vitro short-term chronic phytotoxicity germination and root elongation test were applied to test the effects of nickel (Ni) in seed germination and root elongation in six plants species: Cucumis sativus (Cucurbitaceae), Lepidium sativum and Brassica nigra (Brassicaceae), Trifolium alexandrinum and Medicago sativa (Fabaceae), Phacelia tanacetifolia (Boraginaceae). A naturally Ni rich soil was used to compare the results obtained. Unlike root elongation, germination was not affected by Ni in any of the six species tested. EC50 values, calculated on the root elongation, showed that Ni toxicity decreases in the following order: P. tanacetifolia > B. nigra > C. sativus > L. sativum > M. sativa > T. alexandrinum. The test conducted using soil elutriate revealed a significantly lower effect in both seed germination and root elongation when compared to the results obtained using untreated soil. Conversely, the test performed on soil confirmed the high sensitivity of C. sativus, P. tanacetifolia and L. sativum to Ni. PMID:24288040

  2. Are cactus growth forms related to germination responses to light? A test using Echinopsis species

    NASA Astrophysics Data System (ADS)

    Ortega-Baes, Pablo; Aparicio-González, Mónica; Galíndez, Guadalupe; del Fueyo, Patricia; Sühring, Silvia; Rojas-Aréchiga, Mariana

    2010-05-01

    In this study, we investigated the effect of light regimen (white light vs. darkness) on the germination of 12 species of the Echinopsis genus (tribe Trichocereeae, Cactaceae). This genus presents a variety of growth forms and relatively small and uniform seed size. These traits allowed us to test, within the same linage and removing seed mass effect, the hypothesis that the germination response to light (indifferent to light or positive photoblastic) is related to growth form. Our results reject this hypothesis since no seeds germinated in darkness, so all of the species can be classified as being positively photoblastic. The proportion of seed germination with white light was significantly different among cactus growth forms. Columnar cacti (arborescent, creeping and short) showed a greater proportion of seed germination than barrel and globose cacti. The germination rate differed among growth forms and species. At constant temperatures, creeping columnar cacti presented a significantly higher germination rate than the other growth forms. With alternating temperatures, columnar cacti showed higher germination rates than the other growth forms. The low proportion of seeds that germinated for some species indicates that they show seed dormancy. Our results suggest that germination responses to light in the cactus family could be related to seed mass and phylogenetic constraints.

  3. Identification of irradiated wheat by germination test, DNA comet assay and electron spin resonance

    NASA Astrophysics Data System (ADS)

    Barros, Adilson C.; Freund, Maria Teresa L.; Villavicencio, Ana Lúcia C. H.; Delincée, Henry; Arthur, Valter

    2002-03-01

    In several countries, there has been an increase in the use of radiation for food processing thus improving the quality and sanitary conditions, inhibiting pathogenic microorganisms, delaying the natural aging process and so extending product lifetime. The need to develop analytical methods to detect these irradiated products is also increasing. The goal of this research was to identify wheat irradiated using different radiation doses. Seeds were irradiated with a gamma 60Co source (Gammacell 220 GC) in the Centro de Energia Nuclear na Agricultura and the Instituto de Pesquisas Energéticas e Nucleares. Dose rate used were 1.6 and 5.8kGy/h. Applied doses were 0.0, 0.10, 0.25, 0.50, 0.75, 1.0, and 2.0kGy. After irradiation, seeds were analysed over a 6 month period. Three different detection methods were employed to determine how irradiation had modified the samples. Screening methods consisted of a germination test measuring the inhibition of shooting and rooting and analysis of DNA fragmentation. The method of electron spin resonance spectroscopy allowed a better dosimetric evaluation. These techniques make the identification of irradiated wheat with different doses possible.

  4. A Quick-Test for Biochar Effects on Seed Germination

    EPA Science Inventory

    Biochar is being globally evaluated as a soil amendment to improve soil characteristics (e.g. soil water holding, nutrient exchange, microbiology, pesticides and chemical availability) to increase crop yields. Unfortunately, there are no quick tests to determine what biochar type...

  5. [Testing of germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy].

    PubMed

    Li, Yi-nian; Jiang, Dan; Liu, Ying-ying; Ding, Wei-min; Ding, Qi-shuo; Zha, Liang-yu

    2014-06-01

    Germination rate of rice seeds was measured according to technical stipulation of germination testing for agricultural crop seeds at present. There existed many faults for this technical stipulation such as long experimental period, more costing and higher professional requirement. A rapid and non-invasive method was put forward to measure the germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy. Two varieties of hybrid rice seeds were aged artificially at temperature 45 degrees C and humidity 100% condition for 0, 24, 48, 72, 96, 120 and 144 h. Spectral data of 280 samples for 2 varieties of hybrid rice seeds with different aging time were acquired individually by near-infrared spectra analyzer. Spectral data of 280 samples for 2 varieties of hybrid rice seeds were randomly divided into calibration set (168 samples) and prediction set (112 samples). Gormination rate of rice seed with different aging time was tested. Regression model was established by using partial least squares (PLS). The effect of the different spectral bands on the accuracy of models was analyzed and the effect of the different spectral preprocessing methods on the accuracy of models was also compared. Optimal model was achieved under the whole bands and by using standardization and orthogonal signal correction (OSC) preprocessing algorithms with CM2000 software for spectral data of 2 varieties of hybrid rice seeds, the coefficient of determination of the calibration set (Rc) and that of the prediction set (Rp) were 0.965 and 0.931 individually, standard error of calibration set (SEC) and that of prediction set (SEP) were 1.929 and 2.899 respectively. Relative error between tested value and predicted value for prediction set of rice seeds is below 4.2%. The experimental results show that it is feasible that rice germination rate is detected rapidly and nondestructively by using the near-infrared spectroscopy analysis technology. PMID:25358159

  6. [Testing of germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy].

    PubMed

    Li, Yi-nian; Jiang, Dan; Liu, Ying-ying; Ding, Wei-min; Ding, Qi-shuo; Zha, Liang-yu

    2014-06-01

    Germination rate of rice seeds was measured according to technical stipulation of germination testing for agricultural crop seeds at present. There existed many faults for this technical stipulation such as long experimental period, more costing and higher professional requirement. A rapid and non-invasive method was put forward to measure the germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy. Two varieties of hybrid rice seeds were aged artificially at temperature 45 degrees C and humidity 100% condition for 0, 24, 48, 72, 96, 120 and 144 h. Spectral data of 280 samples for 2 varieties of hybrid rice seeds with different aging time were acquired individually by near-infrared spectra analyzer. Spectral data of 280 samples for 2 varieties of hybrid rice seeds were randomly divided into calibration set (168 samples) and prediction set (112 samples). Gormination rate of rice seed with different aging time was tested. Regression model was established by using partial least squares (PLS). The effect of the different spectral bands on the accuracy of models was analyzed and the effect of the different spectral preprocessing methods on the accuracy of models was also compared. Optimal model was achieved under the whole bands and by using standardization and orthogonal signal correction (OSC) preprocessing algorithms with CM2000 software for spectral data of 2 varieties of hybrid rice seeds, the coefficient of determination of the calibration set (Rc) and that of the prediction set (Rp) were 0.965 and 0.931 individually, standard error of calibration set (SEC) and that of prediction set (SEP) were 1.929 and 2.899 respectively. Relative error between tested value and predicted value for prediction set of rice seeds is below 4.2%. The experimental results show that it is feasible that rice germination rate is detected rapidly and nondestructively by using the near-infrared spectroscopy analysis technology.

  7. Applying Computerized Adaptive Testing in Schools.

    ERIC Educational Resources Information Center

    Olsen, James B.

    1990-01-01

    Presents two studies applying computerized adaptive testing (CAT) in schools. Compared paper-administered, computer-administered, and CAT modes for administering school achievement and assessment tests. Then compared computerized adaptive aptitude test results with individually administered Weschler Intelligence Scale for Children-Revised. Found…

  8. Lunisolar tidal synchronism with biophoton emission during intercontinental wheat-seedling germination tests

    PubMed Central

    Gallep, Cristiano M; Moraes, Thiago A; Červinková, Kateřina; Cifra, Michal; Katsumata, Masakazu; Barlow, Peter W

    2014-01-01

    Synchronic measurements of spontaneous ultra-weak light emission from germinating wheat seedlings both in Brazil and after transportation to Japan, and with a simultaneous series of germinations with local seedlings in the Czech Republic, are presented. A series of tests was also performed with samples returned from Japan to Brazil and results compared with those from undisturbed Brazilian seedlings. Native seedlings presented semi-circadian rhythms of emission which correlated with the gravimetric tidal acceleration at their locality, as did seeds which had been transported from Brazil to Japan, and then returned to Brazil. Here, however, there were very small disturbances within the periodicity of emissions, perhaps as a result of similar tidal profiles at locations whose longitudes are 180° apart, as in this case, different from previous results obtained in Brazil–Germany tests with other longitude shift. This feature of the Brazil and Japan locations may have minimized the requirement for the acclimatization of the transported seed to their new location. PMID:24714075

  9. Applying Motion Constraints Based on Test Data

    NASA Technical Reports Server (NTRS)

    Burlone, Michael

    2014-01-01

    MSC ADAMS is a simulation software that is used to analyze multibody dynamics. Using user subroutines, it is possible to apply motion constraints to the rigid bodies so that they match the motion profile collected from test data. This presentation describes the process of taking test data and passing it to ADAMS using user subroutines, and uses the Morpheus free-flight 4 test as an example of motion data used for this purpose. Morpheus is the name of a prototype lander vehicle built by NASA that serves as a test bed for various experimental technologies (see backup slides for details) MSC.ADAMS"TM" is used to play back telemetry data (vehicle orientation and position) from each test as the inputs to a 6-DoF general motion constraint (details in backup slides) The MSC.ADAMS"TM" playback simulations allow engineers to examine and analyze flight trajectory as well as observe vehicle motion from any angle and at any playback speed. This facilitates the development of robust and stable control algorithms, increasing reliability and reducing development costs of this developmental engine The simulation also incorporates a 3D model of the artificial hazard field, allowing engineers to visualize and measure performance of the developmental autonomous landing and hazard avoidance technology ADAMS is a multibody dynamics solver. It uses forces, constraints, and mass properties to numerically integrate equations of motion. The ADAMS solver will ask the motion subroutine for position, velocity, and acceleration values at various time steps. Those values must be continuous over the whole time domain. Each degree of freedom in the telemetry data can be examined separately; however, linear interpolation of the telemetry data is invalid, since there will be discontinuities in velocity and acceleration.

  10. Reliability analysis applied to structural tests

    NASA Technical Reports Server (NTRS)

    Diamond, P.; Payne, A. O.

    1972-01-01

    The application of reliability theory to predict, from structural fatigue test data, the risk of failure of a structure under service conditions because its load-carrying capability is progressively reduced by the extension of a fatigue crack, is considered. The procedure is applicable to both safe-life and fail-safe structures and, for a prescribed safety level, it will enable an inspection procedure to be planned or, if inspection is not feasible, it will evaluate the life to replacement. The theory has been further developed to cope with the case of structures with initial cracks, such as can occur in modern high-strength materials which are susceptible to the formation of small flaws during the production process. The method has been applied to a structure of high-strength steel and the results are compared with those obtained by the current life estimation procedures. This has shown that the conventional methods can be unconservative in certain cases, depending on the characteristics of the structure and the design operating conditions. The suitability of the probabilistic approach to the interpretation of the results from full-scale fatigue testing of aircraft structures is discussed and the assumptions involved are examined.

  11. Inhibition of raffinose oligosaccharide breakdown delays germination of pea seeds.

    PubMed

    Blöchl, Andreas; Peterbauer, Thomas; Richter, Andreas

    2007-08-01

    Raffinose family oligosaccharides (RFOs) are almost ubiquitous in seeds and have been hypothesized to constitute an important energy source during germination. To test this hypothesis we applied a specific alpha-galactosidase inhibitor (1-deoxygalactonojirimycin, DGJ) to germinating pea seeds, resulting in a complete blocking of RFO breakdown. The germination rates of DGJ-treated seeds dropped drastically to about 25% of controls two days after imbibition. Similarly, the activities of the key enzymes in the galactose salvage pathway galactokinase, UDP-galactose pyrophosphorylase and UDP-galactose 4'-epimerase, were also significantly lower in seeds treated with the inhibitor. The inhibitory effect on germination could be relieved by galactose but only partially by sucrose, indicating that galactose, in addition to providing easily available energy for growth, may also be an important component of the sugar signaling pathway during germination. Taken together our study, for the first time, provides clear evidence that RFOs play an important role for early germination.

  12. Assessment of heavy metals phytotoxicity using seed germination and root elongation tests: a comparison of two growth substrates.

    PubMed

    Di Salvatore, M; Carafa, A M; Carratù, G

    2008-11-01

    Seed germination and root elongation test is used to evaluate hazardous waste sites and to assess toxicity of organic and inorganic compounds. Paper substrate, especially circular filter paper placed inside a Petri dish has long been used for this test. Same reports indicate that filter paper might interfere with the toxicity of inorganic substances, especially metal cations. This study evaluate toxicity of Cd, Pb, Ni, Cu on lettuce, broccoli, tomato and radish seed using two bed material: agar and filter paper. The results show that percent germination is not affected by substrates; vice versa, as for root elongation, the test in agar showed to be more sensible than that the one on filter paper. The radical growth inhibition depends on the metal, on the tested concentration and on the species; among the tested metals, cadmium was the one determining the highest toxic effects on different species and lettuce was the plant that suffered more. From the comparison, it is clearly evident the greater sensibility of the test in agar; on the other hand, the lower sensibility of the test on the filter paper might be caused by the partial and not homogeneous exposition of the root to metal cations.

  13. Assessment of heavy metals phytotoxicity using seed germination and root elongation tests: a comparison of two growth substrates.

    PubMed

    Di Salvatore, M; Carafa, A M; Carratù, G

    2008-11-01

    Seed germination and root elongation test is used to evaluate hazardous waste sites and to assess toxicity of organic and inorganic compounds. Paper substrate, especially circular filter paper placed inside a Petri dish has long been used for this test. Same reports indicate that filter paper might interfere with the toxicity of inorganic substances, especially metal cations. This study evaluate toxicity of Cd, Pb, Ni, Cu on lettuce, broccoli, tomato and radish seed using two bed material: agar and filter paper. The results show that percent germination is not affected by substrates; vice versa, as for root elongation, the test in agar showed to be more sensible than that the one on filter paper. The radical growth inhibition depends on the metal, on the tested concentration and on the species; among the tested metals, cadmium was the one determining the highest toxic effects on different species and lettuce was the plant that suffered more. From the comparison, it is clearly evident the greater sensibility of the test in agar; on the other hand, the lower sensibility of the test on the filter paper might be caused by the partial and not homogeneous exposition of the root to metal cations. PMID:18768198

  14. Rapid bioassessment methods for assessing vegetation toxicity at the Savannah River Site - germination tests and root elongation trials

    SciTech Connect

    Specht, W.L.; Klaine, S.J.; Hook, D.D.

    1996-01-01

    Plants form the basis of all ecosystems including wetlands. Although they are the most abundant life form and are the primary producers for all other organisms, they have received the least attention when it comes to environmental matters. Higher plants have rarely been used in ecotoxicity testing and may not respond in the same manner as algae, which have been used more frequently. The introduction of hazardous waste materials into wetland areas has the potential to alter and damage the ecological processes in these ecosystems. Measuring the impact of these contaminants on higher plants is therefore important and needs further research. Higher plants are useful for detecting both herbicidal toxicity and heavy metal toxicity. For phytotoxicity tests to be practical they must be simple, inexpensive, yet sensitive to a variety of contaminants. A difference between seed germination and root elongation tests is that seed germination tests measure toxicity associated with soils directly, while root elongation tests consider the indirect effects of water-soluble constituents that may be present in site samples.

  15. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested....

  16. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested....

  17. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested....

  18. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested....

  19. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested....

  20. Germination and elongation of flax in microgravity

    NASA Astrophysics Data System (ADS)

    Levine, H.; Anderson, K.; Boody, A.; Cox, D.; Kuznetsov, O.; Hasenstein, K.

    This experiment was conducted as part of a risk mitigation BIOTUBE Precursor hardware demonstration payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to provide a demonstration and test of the newly developed BIOTUBE water delivery subsystem, and to determine the optimal water volume and germination paper combination for the automated imbibition and germination of flax (Linum usitatissimum) seeds in space. Two different substrate treatments of standard laboratory germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. The first consisted of one layer of thick germination paper (designated "heavy"), and the second consisted of one layer of standard germination paper (designated "normal") under one layer of heavy germination paper. The germination paper strips were cut (4 X 1.6 cm) to fit snugly into seed cassettes. The seeds were attached to them by applying guar glue (1.25% w/v) drops to 8 premarked spots and the seeds orientated with the micropyle ends pointing outward. Water was delivered in 50 μL boluses which slowly traveled down the paper via capillary action (eliminating the complications caused by excess water pooling around the seed's surface). The data indicated that the 480 μL water delivery volume provided the best wetness level treatment for both percent germination (90.6%) and overall root growth (mean = 4.1 mm) during the 34 hour spaceflight experiment. The ground control experiment experienced similar results, but with slightly lower rates of germination (84.4%) and significantly shorter root lengths (2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of "Heavy" germination paper generally exhibited better overall growth than the two layered option. This in conjunction with the simplicity of using a single strip per seed cassette argues in favor of its selection. Significant seed position

  1. Test fire environmental testing operations at Mound Applied Technologies

    SciTech Connect

    1992-03-01

    This paper describes Mound Laboratory`s environmental testing operations. The function of environmental testing is to perform quality environmental (thermal, mechanical, spin, resistance, visual) testing/conditioning of inert/explosive products to assure their compliance with specified customer acceptance criteria. Capabilities, organization, equipment specifications, and test facilities are summarized.

  2. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Source of seeds for germination. 201.53 Section 201.53... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from...

  3. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Source of seeds for germination. 201.53 Section 201.53... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from...

  4. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Source of seeds for germination. 201.53 Section 201.53... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from...

  5. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Source of seeds for germination. 201.53 Section 201.53... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from...

  6. Evaluation and refinement of a continuous seed germination and early seedling growth test for the use in the ecotoxicological assessment of soils.

    PubMed

    Gong, P; Wilke, B M; Strozzi, E; Fleischmann, S

    2001-07-01

    Four higher plant species (Avena sativa L., oat; Lepidium sativum L., cress; Brassica rapa Metzg., turnip; and Phaseolus vulgaris L., bush bean) and 15 soils including five mineral oil-contaminated soils were tested to assess a soil-based continuous seed germination and early seedling growth bioassay. Seed germination was recorded and the shoot biomass of 14-day seedlings measured. An automatic self-watering system was compared with the daily hand watering. Results obtained from this study show that the self-watering system had minor effects on both seed germination and early seedling growth, and that soil nutrient status rather than soil texture significantly affected both seedling emergence and shoot biomass. Proportional dilution of suspicious samples from primary tests with an appropriate control soil is recommended for secondary tests. Shoot biomass is a more sensitive measurement endpoint than seed germination. Bush bean should not be recommended for use due to its low sensitivity to mineral oil and poor germination in soil.

  7. Assessment of the phytotoxicity of seaport sediments in the framework of a quarry-deposit scenario: germination tests of sediments aged artificially by column leaching.

    PubMed

    Bedell, J-P; Bazin, C; Sarrazin, B; Perrodin, Y

    2013-07-01

    The aim of the Sustainable Management of Sediments Dredged in Seaports (SEDIGEST) project is to assess the risks of treated port sediments for terrestrial ecosystems when deposited in quarries. We simulated the "ageing" of these sediments up to the "moment" when plants can germinate. Sediments were leached by water percolating through a laboratory column. Sediments 1 and 2, taken from the port of Toulon (France), were dried and aired. Sediment 3, taken from the port of Guilvinec (France), was stabilised with lime. Phytotoxicity was evaluated on the three artificially aged sediments using germination and early development tests (48 h to 7 days) by Phytotoxkit F(TM) bioassays. The three dilutions tested were performed with the reference "ISO substrate" and with Lolium perenne sp. (rye grass), Sinapis alba (white mustard), and Lepidium sativum (watercress). The tests performed with sediments 1 and 2 showed (1) a decrease of their toxicity to the germination of the species selected following leaching and (2) that L. perenne was the most sensitive species. The tests performed with sediment 3 showed that it was improper for colonisation even after leaching simulating 16 months of ageing. These germination tests on aged sediments identified the effects of leaching and made it possible to appreciate the capacity of the sediments to allow colonisation by plants.

  8. Does Cold Plasma Affect Breaking Dormancy and Seed Germination? A Study on Seeds of Lamb's Quarters (Chenopodium album agg.)

    NASA Astrophysics Data System (ADS)

    Božena, Šerá; Michal, Šerý; Vitězslav, Štrañák; Petr, Špatenka; Milan, tichý

    2009-12-01

    Low-pressure discharge is applied for stimulation of germination of two seed lots of Lamb's Quarters (Chenopodium album agg.) with different starting germinations (17%, 8%) and in different stages of dormancy. Different exposition durations with cold plasma treatment were applied. The variable of the ratio cumulative germination was calculated. The Richards' equation was used for curve-fitting and simulation of the growth curves. Population parameters, namely Vi - viability, Me - time, Qu - dispersion, and Sk - skewness, counted from the curves described the germination rate well. Significant differences among Qu confirmed the erratic dormancy and gradual germination of Lamb's Quarters. No difference in the Me parameter was found between two tested seed lots, and no interspecies characteristics were changed using low-pressure discharge. The results suggested that plasma treatment changed seed germination in Lamb's Quarters seeds.

  9. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Number of seeds for germination. 201.54 Section 201.54... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of...

  10. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of...

  11. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Number of seeds for germination. 201.54 Section 201.54... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of...

  12. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Number of seeds for germination. 201.54 Section 201.54... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of...

  13. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Number of seeds for germination. 201.54 Section 201.54... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of...

  14. 7 CFR 201.6 - Germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Germination. 201.6 Section 201.6 Agriculture... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered...

  15. 7 CFR 201.6 - Germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Germination. 201.6 Section 201.6 Agriculture... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered...

  16. 7 CFR 201.6 - Germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.6 Section 201.6 Agriculture... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered...

  17. 7 CFR 201.6 - Germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Germination. 201.6 Section 201.6 Agriculture... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered...

  18. 7 CFR 201.6 - Germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Germination. 201.6 Section 201.6 Agriculture... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered...

  19. Flight control system design factors for applying automated testing techniques

    NASA Technical Reports Server (NTRS)

    Sitz, Joel R.; Vernon, Todd H.

    1990-01-01

    Automated validation of flight-critical embedded systems is being done at ARC Dryden Flight Research Facility. The automated testing techniques are being used to perform closed-loop validation of man-rated flight control systems. The principal design features and operational experiences of the X-29 forward-swept-wing aircraft and F-18 High Alpha Research Vehicle (HARV) automated test systems are discussed. Operationally applying automated testing techniques has accentuated flight control system features that either help or hinder the application of these techniques. The paper also discusses flight control system features which foster the use of automated testing techniques.

  20. Toxicity test of the F-Area seep soils by laboratory lettuce seed germination and seedling growth

    SciTech Connect

    Eaton, D.; Murphy, C.E.

    1993-09-01

    This study is a follow-up of a similar study done by Loehle (1990). The objectives of the original study were to: (1) measure the toxicity of groundwater contaminated by the F-Area seepage basins where this water surfaces in a seepline along Fourmile Branch and (2) to evaluate the effectiveness of rainwater for washing contaminants from the soil. Results of seed germination tests show no significant difference between water extracted from one extraction of F-Area seepline soil, soil from a control area, the sixth consecutive extraction from F-Area soil, and a deionized water control. A root-growth assay on the same seeds shows a significant effect with the order of growth, first extraction of F-Area soil

  1. Genotoxicity testing of 3,4,5-trimethylfuran-2(5H)-one, a compound from plant-derived smoke with germination inhibitory activity.

    PubMed

    Light, Marnie E; Anthonissen, Roel; Maes, Annemarie; Verschaeve, Luc; Pošta, Martin; Van Staden, Johannes

    2015-01-15

    Plant-derived smoke and certain smoke compounds improve seed germination and enhance seedling growth of many species. Thus, smoke-infused water and the active smoke-derived compounds have the potential to be used in different agricultural and horticultural applications. However, despite these interesting and potentially practical properties, it should also be ascertained whether such compounds may pose a health risk, particularly if they are to be used in the production of food or fodder crops. Amongst some of the aspects that would be important to understand are any possible genotoxic properties that the compounds may possess due to potential carry-over effects. Here, we report on a genotoxicity study of 3,4,5-trimethylfuran-2(5H)-one, a compound from plant-derived smoke previously shown to have germination inhibitory activity. Using two in vitro tests, namely the bacterial VITOTOX® test (with/without S9 metabolic activation) and the cytome assay on human C3A cells, no genotoxicity or toxicity was found. Furthermore, these results support a previous study where a related smoke-derived compound with germination promoting properties was investigated.

  2. Integrated preclinical photosafety testing strategy for systemically applied pharmaceuticals.

    PubMed

    Schümann, Jens; Boudon, Stéphanie; Ulrich, Peter; Loll, Nathalie; Garcia, Déborah; Schaffner, René; Streich, Jeannine; Kittel, Birgit; Bauer, Daniel

    2014-05-01

    Phototoxic properties of systemically applied pharmaceuticals may be the cause of serious adverse drug reactions. Therefore, a reliable preclinical photosafety assessment strategy, combining in vitro and in vivo approaches in a quantitative manner, is important and has not been described so far. Here, we report the establishment of an optimized modified murine local lymph node assay (LLNA), adapted for phototoxicity assessment of systemically applied compounds, as well as the test results for 34 drug candidates in this in vivo photo-LLNA. The drug candidates were selected based on their ability to absorb ultraviolet/visible light and the photo irritation factors (PIFs) determined in the well-established in vitro 3T3 neutral red uptake phototoxicity test. An in vivo phototoxic potential was identified for 13 of these drug candidates. The use of multiple dose levels in the described murine in vivo phototoxicity studies enabled the establishment of no- and/or lowest-observed-adverse-effect levels (NOAELs/LOAELs), also supporting human photosafety assessment. An in vitro-in vivo correlation demonstrated that a drug candidate classified as "phototoxic" in vitro is not necessarily phototoxic in vivo. However, the probability for a drug candidate to cause phototoxicity in vivo clearly correlated with the magnitude of the phototoxicity identified in vitro.

  3. A general diagnostic model applied to language testing data.

    PubMed

    von Davier, Matthias

    2008-11-01

    Probabilistic models with one or more latent variables are designed to report on a corresponding number of skills or cognitive attributes. Multidimensional skill profiles offer additional information beyond what a single test score can provide, if the reported skills can be identified and distinguished reliably. Many recent approaches to skill profile models are limited to dichotomous data and have made use of computationally intensive estimation methods such as Markov chain Monte Carlo, since standard maximum likelihood (ML) estimation techniques were deemed infeasible. This paper presents a general diagnostic model (GDM) that can be estimated with standard ML techniques and applies to polytomous response variables as well as to skills with two or more proficiency levels. The paper uses one member of a larger class of diagnostic models, a compensatory diagnostic model for dichotomous and partial credit data. Many well-known models, such as univariate and multivariate versions of the Rasch model and the two-parameter logistic item response theory model, the generalized partial credit model, as well as a variety of skill profile models, are special cases of this GDM. In addition to an introduction to this model, the paper presents a parameter recovery study using simulated data and an application to real data from the field test for TOEFL Internet-based testing.

  4. Reliability Testing Procedure for MEMS IMUs Applied to Vibrating Environments

    PubMed Central

    De Pasquale, Giorgio; Somà, Aurelio

    2010-01-01

    The diffusion of micro electro-mechanical systems (MEMS) technology applied to navigation systems is rapidly increasing, but currently, there is a lack of knowledge about the reliability of this typology of devices, representing a serious limitation to their use in aerospace vehicles and other fields with medium and high requirements. In this paper, a reliability testing procedure for inertial sensors and inertial measurement units (IMU) based on MEMS for applications in vibrating environments is presented. The sensing performances were evaluated in terms of signal accuracy, systematic errors, and accidental errors; the actual working conditions were simulated by means of an accelerated dynamic excitation. A commercial MEMS-based IMU was analyzed to validate the proposed procedure. The main weaknesses of the system have been localized by providing important information about the relationship between the reliability levels of the system and individual components. PMID:22315550

  5. Applying the Implicit Association Test to Measure Intolerance of Uncertainty.

    PubMed

    Mosca, Oriana; Dentale, Francesco; Lauriola, Marco; Leone, Luigi

    2016-08-01

    Intolerance of Uncertainty (IU) is a key trans-diagnostic personality construct strongly associated with anxiety symptoms. Traditionally, IU is measured through self-report measures that are prone to bias effects due to impression management concerns and introspective difficulties. Moreover, self-report scales are not able to intercept the automatic associations that are assumed to be main determinants of several spontaneous responses (e.g., emotional reactions). In order to overcome these limitations, the Implicit Association Test (IAT) was applied to measure IU, with a particular focus on reliability and criterion validity issues. The IU-IAT and the Intolerance of Uncertainty Inventory (IUI) were administered to an undergraduate student sample (54 females and 10 males) with a mean age of 23 years (SD = 1.7). Successively, participants were asked to provide an individually chosen uncertain event from their own lives that may occur in the future and were requested to identify a number of potential negative consequences of it. Participants' responses in terms of cognitive thoughts (i.e., cognitive appraisal) and worry reactions toward these events were assessed using the two subscales of the Worry and Intolerance of Uncertainty Beliefs Questionnaire. The IU-IAT showed an adequate level of internal consistency and a not significant correlation with the IUI. A path analysis model, accounting for 35% of event-related worry, revealed that IUI had a significant indirect effect on the dependent variable through event-related IU thoughts. By contrast, as expected, IU-IAT predicted event-related worry independently from IU thoughts. In accordance with dual models of social cognition, these findings suggest that IU can influence event-related worry through two different processing pathways (automatic vs. deliberative), supporting the criterion and construct validity of the IU-IAT. The potential role of the IU-IAT for clinical applications was discussed. PMID:27451266

  6. Similitude requirements and scaling relationships as applied to model testing

    NASA Technical Reports Server (NTRS)

    Wolowicz, C. H.; Brown, J. S., Jr.; Gilbert, W. P.

    1979-01-01

    The similitude requirements for the most general test conditions are presented. These similitude requirements are considered in relation to the scaling relationships, test technique, test conditions (including supersonic flow), and test objectives. Particular emphasis is placed on satisfying the various similitude requirements for incompressible and compressible flow conditions. For free flying models tests, the test velocities for incompressible flow are scaled from Froude number similitude requirements and those for compressible flow are scaled from Mach number similitude requirements. The limitations of various test techniques are indicated, with emphasis on the free flying model.

  7. Effects of disturbance on germination and seedling establishment in a coastal prairie grassland: A test of the competitive release hypothesis

    USGS Publications Warehouse

    Jutila, H.M.; Grace, J.B.

    2002-01-01

    1. We evaluated the responses of native grassland sods to a variety of types of disturbance in order to assess hypotheses about the competitive effects of established vegetation on seed germination and seedling establishment. In particular, we consider whether germination is more responsive to the magnitude and duration of vegetation removal (competitive release) or to individual disturbance types (specific effects). 2. Field-collected sods of coastal tallgrass prairie were subjected to no manipulation, cutting with clippings left, cutting with clippings removed (hayed), burning, and complete destruction of established vegetation under greenhouse conditions. The emergence and fate of seedlings, as well as light penetration through the canopy, were followed for a period of 4.5 months. 3. Total seedling emergence increased from cut to control, hayed, burned and plants-removed treatments. Several periods of increased seedling emergence suggested responses to both light penetration and seasonal change. 4. Species richness was lowest in cut sods and highest in sods that had plants removed or were burned. Rarefaction analysis showed that these differences were largely those expected from differences in seedling number, except for the cut treatment, which produced fewer species per seedling than other treatments. 5. Indicator species analysis and ordination methods revealed that seedling community composition overlapped strongly across all treatments, although the area of ordination space did increase with increasing numbers of seedlings. 6. Overall, most of the effects of disturbance could be explained by cumulative light penetration to the soil surface, an indicator of total competitive release, although a few specific effects could be found (particularly for the cutting treatment). Thus, these results generally support the competitive release hypothesis.

  8. Effect of fungicide on Wyoming big sagebrush seed germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because fungal infection may complicate both the logistics and the interpretation of germination tests, seeds are sometimes treated with chemical fungicides. Fungicides may reduce the germination rate and/or germination percentage, and should be avoided unless fungal contamination is severe enough ...

  9. A Germination Simulation.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1995-01-01

    Presents an activity that involves using sponge seedlings to demonstrate the germination process without the usual waiting period. Discusses epigeous versus hypogeous germination, and cotyledon number and biodiversity. (JRH)

  10. A simple and reliable method to detect gamma irradiated lentil ( Lens culinaris Medik.) seeds by germination efficiency and seedling growth test

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Sadhan K.

    2002-05-01

    Germination efficiency and root/shoot length of germinated seedling is proposed to identify irradiated lentil seeds. Germination percentage was reduced above 0.2 kGy and lentil seeds were unable to germinate above 1.0 kGy dose. The critical dose that prevented the root elongation varied from 0.1 to 0.5 kGy. The sensitivity of lentil seeds to gamma irradiation was inversely proportional to moisture content of the seeds. Radiation effects could be detected in seeds even 12 months storage after gamma irradiation.

  11. Applying the Minimax Principle to Sequential Mastery Testing. Research Report.

    ERIC Educational Resources Information Center

    Vos, Hans J.

    This paper derives optimal rules for sequential mastery tests. In a sequential mastery test, the decision is to classify a subject as a master or a nonmaster or to continue sampling and administering another random item. The framework of minimax sequential decision theory (minimum information approach) is used; that is, optimal rules are obtained…

  12. Oxygen requirement of germinating flax seeds

    NASA Technical Reports Server (NTRS)

    Kuznetsov, Oleg A.; Hasenstein, K. H.; Hasentein, K. H. (Principal Investigator)

    2003-01-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

  13. Oxygen requirement of germinating flax seeds

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Oleg A.; Hasenstein, K. H.

    2003-05-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax ( Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume = 14 mL) and after 36 h measured the root length. At 90 μl O 2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O 2 we determined the lower limit of reliable germination to be 10 vol. % O 2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination.

  14. Multi-matrix, dual polarity, tandem mass spectrometry imaging strategy applied to a germinated maize seed: toward mass spectrometry imaging of an untargeted metabolome

    DOE PAGESBeta

    Feenstra, Adam D.; Hansen, Rebecca L.; Lee, Young Jin

    2015-08-27

    Mass spectrometry imaging (MSI) provides high spatial resolution information that is unprecedented in traditional metabolomics analyses; however, the molecular coverage is often limited to a handful of compounds and is insufficient to understand overall metabolomic changes of a biological system. Here, we propose an MSI methodology to increase the diversity of chemical compounds that can be imaged and identified, in order to eventually perform untargeted metabolomic analysis using MSI. We use the desorption/ionization bias of various matrixes for different metabolite classes along with dual polarities and a tandem MSI strategy. The use of multiple matrixes and dual polarities allows usmore » to visualize various classes of compounds, while data-dependent MS/MS spectra acquired in the same MSI scans allow us to identify the compounds directly on the tissue. In a proof of concept application to a germinated corn seed, a total of 166 unique ions were determined to have high-quality MS/MS spectra, without counting structural isomers, of which 52 were identified as unique compounds. According to an estimation based on precursor MSI datasets, we expect over five hundred metabolites could be potentially identified and visualized once all experimental conditions are optimized and an MS/MS library is available. Finally, metabolites involved in the glycolysis pathway and tricarboxylic acid cycle were imaged to demonstrate the potential of this technology to better understand metabolic biology.« less

  15. Multi-matrix, dual polarity, tandem mass spectrometry imaging strategy applied to a germinated maize seed: toward mass spectrometry imaging of an untargeted metabolome

    SciTech Connect

    Feenstra, Adam D.; Hansen, Rebecca L.; Lee, Young Jin

    2015-08-27

    Mass spectrometry imaging (MSI) provides high spatial resolution information that is unprecedented in traditional metabolomics analyses; however, the molecular coverage is often limited to a handful of compounds and is insufficient to understand overall metabolomic changes of a biological system. Here, we propose an MSI methodology to increase the diversity of chemical compounds that can be imaged and identified, in order to eventually perform untargeted metabolomic analysis using MSI. We use the desorption/ionization bias of various matrixes for different metabolite classes along with dual polarities and a tandem MSI strategy. The use of multiple matrixes and dual polarities allows us to visualize various classes of compounds, while data-dependent MS/MS spectra acquired in the same MSI scans allow us to identify the compounds directly on the tissue. In a proof of concept application to a germinated corn seed, a total of 166 unique ions were determined to have high-quality MS/MS spectra, without counting structural isomers, of which 52 were identified as unique compounds. According to an estimation based on precursor MSI datasets, we expect over five hundred metabolites could be potentially identified and visualized once all experimental conditions are optimized and an MS/MS library is available. Finally, metabolites involved in the glycolysis pathway and tricarboxylic acid cycle were imaged to demonstrate the potential of this technology to better understand metabolic biology.

  16. [Effects of seed priming on physiology of seed germination and seeding growth of Marsdenia tenacissima under NaCl stress].

    PubMed

    Xiao, Xue-feng; Liu, Li; Guo, Qiao-sheng; Li, Chao; Wang, Ping-li; Yang, Sheng-chao; Hang, Yue-yu

    2015-01-01

    To offer the reference and method for salt damage in the cultivation of Marsdenia tenacissima, the seeds of M. tenacissima collected from Maguan city ( Yunnan province) were taken as the test materials to study the effects of different priming materials on improving germination and growth under high-level salt stress condition. Four different treatments, which were GA3, KNO3-KH2PO4, PEG-6000, NaCl, combined with ANOVA were applied to test the performance of germination energy, germination percentage, germination index, MDA, SOD, and CAT. The results showed that the seed germination was obviously inhibited under salt stress and the soaked seeds with different priming materials could alleviate the damage of salt stress. Under these treatments, the activities of SOD, CAT the content of soluble protein significantly increased. While the content of MDA significantly decreased. The maximum index was obtained when treated with 1.20% KNO3-KH2PO4, the germination percentage increased from 52.67% to 87.33% and the activity of SOD increased from 138.01 to 219.44 respectively. Comparing with the treatment of 1.20% KNO3-KH2PO4, the germination percentage of treating with 300 mg x L(-1) GA3 increased from 52.67% to 80.67%, while the activity of SOD increased from 138.01 to 444.61.

  17. Aerodynamic Reconstruction Applied to Parachute Test Vehicle Flight Data Analysis

    NASA Technical Reports Server (NTRS)

    Cassady, Leonard D.; Ray, Eric S.; Truong, Tuan H.

    2013-01-01

    The aerodynamics, both static and dynamic, of a test vehicle are critical to determining the performance of the parachute cluster in a drop test and for conducting a successful test. The Capsule Parachute Assembly System (CPAS) project is conducting tests of NASA's Orion Multi-Purpose Crew Vehicle (MPCV) parachutes at the Army Yuma Proving Ground utilizing the Parachute Test Vehicle (PTV). The PTV shape is based on the MPCV, but the height has been reduced in order to fit within the C-17 aircraft for extraction. Therefore, the aerodynamics of the PTV are similar, but not the same as, the MPCV. A small series of wind tunnel tests and computational fluid dynamics cases were run to modify the MPCV aerodynamic database for the PTV, but aerodynamic reconstruction of the flights has proven an effective source for further improvements to the database. The acceleration and rotational rates measured during free flight, before parachute inflation but during deployment, were used to con rm vehicle static aerodynamics. A multibody simulation is utilized to reconstruct the parachute portions of the flight. Aerodynamic or parachute parameters are adjusted in the simulation until the prediction reasonably matches the flight trajectory. Knowledge of the static aerodynamics is critical in the CPAS project because the parachute riser load measurements are scaled based on forebody drag. PTV dynamic damping is critical because the vehicle has no reaction control system to maintain attitude - the vehicle dynamics must be understood and modeled correctly before flight. It will be shown here that aerodynamic reconstruction has successfully contributed to the CPAS project.

  18. Applying fiber optical methods for toxicological testing in vitro

    NASA Astrophysics Data System (ADS)

    Maerz, Holger K.; Buchholz, Rainer; Emmrich, Frank; Fink, Frank; Geddes, Clive L.; Pfeifer, Lutz; Raabe, Ferdinand; Scheper, Thomas-Helmut; Ulrich, Elizabeth; Marx, Uwe

    1999-04-01

    The new medical developments, e.g. immune therapy, patient oriented chemotherapy or even gene therapy, create a questionable doubt to the further requirement of animal test. Instead the call for humanitarian reproductive in vitro models becomes increasingly louder. Pharmaceutical usage of in vitro has a long proven history. In cancer research and therapy, the effect of chemostatica in vitro in the so-called oncobiogram is being tested; but the assays do not always correlate with in vivo-like drug resistance and sensitivity. We developed a drug test system in vitro, feasible for therapeutic drug monitoring by the combination of tissue cultivation in hollow fiber bioreactors and fiber optic sensors for monitoring the pharmaceutical effect. Using two fiber optic sensors - an optical oxygen sensor and a metabolism detecting Laserfluoroscope, we were able to successfully monitor the biological status of tissue culture and the drug or toxic effects of in vitro pharmaceutical testing. Furthermore, we developed and patented a system for monitoring the effect of minor toxic compounds which can induce Sick Building Syndrome.

  19. TESTING THE IDEAS GUIDELINES AS APPLIED TO PLUTONIUM INTAKES.

    PubMed

    Bull, Richard; Roberts, Gareth

    2016-09-01

    The IDEAS Guidelines [Doerfel, H., et al General Guidelines for the Estimation of Committed Effective Dose from Incorporation Monitoring Data. Report FZKA 7243, Forschungszentrum Karlsruhe, GmbH (2006); Castellani, C. M., Marsh, J. W., Hurtgen, C., Blanchardon, E., Berard, P., Giusani, A. and Lopez, M. A. IDEAS Guidelines (Version 2) for the Estimation of Committed Doses from Incorporation Monitoring Data. EURADOS Report 2013-01, Braunschweig (2013)] provide a structured approach to the assessment of intakes of radionuclides. In order to check that the guidelines, when applied to typical monitoring programmes, lead to reliable assessments, a number of numerically-generated datasets have been constructed and assessed using the guidelines. The dose and intake obtained by the assessment can be compared with the 'true' dose and intake. In this way, the accuracy of the IDEAS assessment process can be examined when applied to monitoring programmes that are typically used in the nuclear industry. The simulations focus on assessments carried out as a result of elevated (239)Pu activities in routine urine samples, which lead to follow-up urine and faecal samples being provided. Cases where the assessor makes the correct initial assumption about lung solubility can be compared with cases where this initial choice is wrong. The results of these simulations and the implication for the use of monitoring programmes are discussed. PMID:26822423

  20. Comparing Applied Literacy and Basic Skills Tests as Measures of Adult Literacy Performance.

    ERIC Educational Resources Information Center

    Sabatini, John P.; And Others

    The Tests of Adult Basic Education (TABE) is a widely used multiple-choice test battery of basic skills in reading, language, and mathematics. The Test of Applied Literacy Skills (TALS) is an applied literacy battery consisting of document, prose, and quantitative literacy tests. The central issue in this study was the relationship of the TABE and…

  1. Munsell's 100-hue test applied to color films

    NASA Astrophysics Data System (ADS)

    McCann, John J.

    1999-12-01

    The experiments described in this paper use the Munsell 100 Hue test to measure color film's ability to order chips the same as humans. The procedure is to photograph the chips in daylight and to scan the dye densities in the processed prints. If the film confuses colors, as colorblind and color anomalous humans do, then the dye density sequence will not be monotonic. Local reversals in dye density imply spectral responses different than humans. A triplet of monotonic dye curves would mimic the color response of people with much better than average color discrimination.

  2. Test Structures Applied to the Rapid Prototyping of Sensors

    NASA Technical Reports Server (NTRS)

    Buehler, M.; Chang, L-J.; Martin, D.

    1997-01-01

    Recently, test structures were used to aid in the rapid development of a gas sensor and pressure sensor. These sensors were fabricated using co-fired ceramic technology and a multiproject approach. This talk will describe results obtained from a ceramic substrate which contained 36 chips with six variants including the sensors, process control monitors, and an interconnect chip. As far as the authors know, this is the first implementation of multi-projects in co-fired ceramic substrate. The gas sensor is being developed for the Space Shuttle and the pressure gage is being developed as a Martian barometer.

  3. Advanced Background Subtraction Applied to Aeroacoustic Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    Bahr, Christopher J.; Horne, William C.

    2015-01-01

    An advanced form of background subtraction is presented and applied to aeroacoustic wind tunnel data. A variant of this method has seen use in other fields such as climatology and medical imaging. The technique, based on an eigenvalue decomposition of the background noise cross-spectral matrix, is robust against situations where isolated background auto-spectral levels are measured to be higher than levels of combined source and background signals. It also provides an alternate estimate of the cross-spectrum, which previously might have poor definition for low signal-to-noise ratio measurements. Simulated results indicate similar performance to conventional background subtraction when the subtracted spectra are weaker than the true contaminating background levels. Superior performance is observed when the subtracted spectra are stronger than the true contaminating background levels. Experimental results show limited success in recovering signal behavior for data where conventional background subtraction fails. They also demonstrate the new subtraction technique's ability to maintain a proper coherence relationship in the modified cross-spectral matrix. Beam-forming and de-convolution results indicate the method can successfully separate sources. Results also show a reduced need for the use of diagonal removal in phased array processing, at least for the limited data sets considered.

  4. When the FRAX® test is applied to controlled clinical trials

    PubMed Central

    Fiore, Carmelo Erio; Gaudio, Agostino

    2012-01-01

    Summary FRAX® is a computer-based algorithm developed by the World Health Organization Collaborating Centre for Metabolic Bone Diseases in Sheffield (UK). This algorithm calculates fracture probability from easily obtained clinical risk factors in men and women: age, sex, body mass index and dichotomized variables comprising prior fragility fracture, parental history of hip fracture, current tobacco smoking, use of long-term oral glucocorticoid, rheumatoid arthritis, other causes of secondary osteoporosis and high alcohol consumption (femoral neck bone mineral density can be optionally input to enhance fracture risk prediction). The output of FRAX® is the 10-year probability of a major osteoporotic fracture (hip, clinical spine, humerus or wrist fracture) and the 10-year probability of hip fracture. Recently various Authors have re-evaluated the effectiveness of drugs approved for postmenopausal osteoporosis to test whether they are more effective in women with higher FRAX® probabilities. PMID:23289024

  5. Evaluation of strategy for testing thyroid function applied to hypothyroidism.

    PubMed Central

    Corns, C M; Miller, A L

    1986-01-01

    A strategy for testing thyroid function with discretionary assay of thyroid stimulating hormone (TSH) following initial measurement of total plasma thyroxine (tT4) was retrospectively evaluated in relation to the diagnosis of primary hypothyroidism. Over a two year period 14 641 tT4 assays were done and 6887 TSH assays, of which 29% were initiated in the laboratory. The percentage of raised TSH values (over 5 mU/1) was similar to those for clinician and pathologist initiated requests (23.2% and 23.6%). Some TSH requests (1620) were cancelled; when 212 of these were subsequently analysed the TSH value was raised in 5.7% The incidence of raised TSH values in 188 patients with a tT4 below 100 nmol/1 (7.8 micrograms/100 ml), in whom TSH was not requested, was 5.3% Most of these raised TSH results could be readily explained by information available to the requesting clinician but not given on the request form. PMID:3082940

  6. Phytotoxic effects of sewage sludge extracts on the germination of three plant species.

    PubMed

    Ramírez, Wilson A; Domene, Xavier; Andrés, Pilar; Alcañiz, Josep M

    2008-11-01

    In order to evaluate the ability of three types of extracts to explain the ecotoxicological risk of treated municipal sewage sludges, the OECD 208A germination test was applied using three plants (Lolium perenne L., Brassica rapa L., and Trifolium pratense L.). Three equivalent batches of sludge, remained as dewatered sludge, composted with plant remains and thermally dried, from an anaerobic waste water treatment plant were separated. Samples from these three batches were extracted in water, methanol, and dichloromethane. Plant bioassays were performed and the Germination Index (GI) for the three plants was evaluated once after a period of 10 days. Germination in extracts was always lower than the respective controls. The germination in composted sludge (GI 40.9-86.2) was higher than the dewatered (GI 2.9-45.8), or thermally dried sludges (GI 24.6-64.4). A comparison of the germination between types of extracts showed differences for dewatered sludge with the three plants, where the water and methanol extracts had significantly lower germination than the dichloromethane extract. A higher half maximal effective concentration (EC50) in composted extracts was established, mainly in the water extract (EC50 431-490 g kg(-1)). On the contrary, the germination was strongly inhibited in the water extract of the dewatered sludge (EC50 14 g kg(-1)). The germination was positively correlated with the degree of organic matter stability of the parent sludge, and an inverse correlation was detected for total nitrogen, hydrolysable nitrogen and ammonium content. It is concluded that the phytotoxic effect of the water extract is more closely related to hydrophilic substances rather than lipophilic ones, and care must be taken with dewatered sludge application, especially with their aqueous eluates. Results obtained in this work show the suitability of the use of sludge extracts in ecotoxic assays and emphasize the relevance of sewage sludge stabilization by post

  7. Germination and elongation of flax in microgravity

    NASA Technical Reports Server (NTRS)

    Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

    2003-01-01

    This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax (Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 microliters) outperforming the 400 microliters and 320 microliters volumes for percent germination (90.6%) and root growth (mean=4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean=2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  8. Germination and elongation of flax in microgravity

    NASA Astrophysics Data System (ADS)

    Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

    2003-05-01

    This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax ( Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 μL) outperforming the 400 μL, and 320 μL volumes for percent germination (90.6%) and root growth (mean = 4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean = 2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions.

  9. Priming effects on seed germination in Tecoma stans (Bignoniaceae) and Cordia megalantha (Boraginaceae), two tropical deciduous tree species

    NASA Astrophysics Data System (ADS)

    Alvarado-López, Sandra; Soriano, Diana; Velázquez, Noé; Orozco-Segovia, Alma; Gamboa-deBuen, Alicia

    2014-11-01

    Successful revegetation necessarily requires the establishment of a vegetation cover and one of the challenges for this is the scarce knowledge about germination and seedling establishment of wild tree species. Priming treatments (seed hydration during a specific time followed by seed dehydration) could be an alternative germination pre-treatment to improve plant establishment. Natural priming (via seed burial) promotes rapid and synchronous germination as well as the mobilisation of storage reserves; consequently, it increases seedling vigour. These metabolic and physiological responses are similar to those occurring as a result of the laboratory seed priming treatments (osmopriming and matrix priming) applied successfully to agricultural species. In order to know if natural priming had a positive effect on germination of tropical species we tested the effects of natural priming on imbibition kinetics, germination parameters (mean germination time, lag time and germination rate and percentage) and reserve mobilisation in the seeds of two tree species from a tropical deciduous forest in south-eastern México: Tecoma stans (L Juss. Ex Kunth) and Cordia megalantha (S.F Blake). The wood of both trees are useful for furniture and T. stans is a pioneer tree that promotes soil retention in disturbed areas. We also compared the effect of natural priming with that of laboratory matrix priming (both in soil). Matrix priming improved germination of both studied species. Natural priming promoted the mobilisation of proteins and increased the amount of free amino acids and of lipid degradation in T. stans but not in C. megalantha. Our results suggest that the application of priming via the burial of seeds is an easy and inexpensive technique that can improve seed germination and seedling establishment of tropical trees with potential use in reforestation and restoration practices.

  10. The oxygen requirement of germinating flax seeds

    NASA Astrophysics Data System (ADS)

    Kuznetsov, O.; Hasenstein, K.

    Experiments for earth orbit are typically prepared on the ground and often germinated in orbit in order to study gravity effects on developing seedlings. Germination requires the breakdown of storage compounds and respiration. In orbit the formation of a water layer around the seed may further limit oxygen availability. Therefore, the oxygen content of the available gas volume is one of the limiting factors for seed germination. In preparation for an upcoming shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware. We tested per seed chamber (gas volume = 14 mL, O2 = 2.9 mL) between 4 to 32 seeds glued to germination paper by 1% (w/v) gum guar. A lexan cover and a gasket hermetically sealed each of the eight chambers. For imbibition of the seeds a previously optimized amount of distilled water was dispensed through sealed inlets. The seedlings were allowed to grow for either 32 to 48 h on a clinostat or without microgravity simulation. Then their root length was measured. With 32 seeds per chamber, four times the intended number of seeds for the flight, the germination rate decreased from 94 to 69%, and the root length was reduced by 20%. Experiments on the germination and root length in controlled atmospheres (5, 10, 15 and 21% O2 ) suggest that germination and growth for two days requires about 200 :l of O (1 mL air) per seed. Our2 experiments correlate oxygen dependency from seed mass and germination temperature, and analyze accumulation of gaseous metabolites (supported by NASA grant NAG10-0190).

  11. Variation in the amount of petrolatum preparation applied at patch testing.

    PubMed

    Bruze, Magnus; Frick-Engfeldt, Malin; Gruvberger, Birgitta; Isaksson, Marléne

    2007-01-01

    The elicitation of a positive patch test reaction in a given individual depends upon the dose of the sensitizer applied, the patch test technique and the occlusion time. The dose is determined by the concentration and volume/amount of test preparation applied. If the same amount/volume of a test preparation is applied all the time with the same test technique (same area of skin) and occlusion time, it is appropriate to use concentration as a dose parameter. Most contact sensitizers are incorporated in petrolatum (pet.). With pet. as vehicle, it is impossible to repeatedly apply an exact volume/amount. This study was performed to investigate the inter- and intra-individual variation of pet. preparation applied at patch testing by 3 technicians. Weighing demonstrated that the 3 technicians had about the same precision in their pet. application. The investigation demonstrates that there is both an inter-individual (statistically significant) and intra-individual variation in the amounts of pet. applied at patch testing for the 3 technicians. Presently, there is no recommendation on what amount of pet. preparation to apply, which merits a decision to be taken based on thorough investigations on the appropriate volumes of pet. preparation to be applied in various patch test systems.

  12. Effects of soil quality and depth on seed germination and seedling survival at the Nevada test site

    SciTech Connect

    Blomquist, K.W.; Lyon, G.E.

    1993-12-31

    The Nuclear Waste Policy Act, as amended in 1987, directs the US Department of Energy (DOE) to study Yucca Mountain, in southern Nevada, as a potential site for long-term storage of high-level nuclear waste. DOE policy mandates the restoration of all lands disturbed by site characterization activities and DOE has developed an environmental program that is to be implemented during site characterization activities at Yucca.Mountain. DOE is currently conducting reclamation feasibility trials as part of this environmental program. No topsoil was saved on disturbances during early site investigation and minimal soil remains at existing disturbances on Yucca Mountain. A study was developed to test the effects of soil quality and depth on seedling emergence and survival. A series of plots was established and two treatments were tested. The first treatment compared native topsoil to subsoil imported from a borrow pit. The second treatment compared four different depth ranges of both soil types. All plots received identical seeding treatments. Seedling density was measured after emergence. Overall seedling densities were low, averaging 10.3 {plus_minus} 8.8 (SD) plants/m{sup 2}. Statistical analysis revealed a significant interaction between the two treatment factors. The subsoil had increasing densities from the deep soil depths to the shallow depths while the topsoil had increasing densities from the shallow soil depths to the deep depths. The cause of this interaction may have resulted from the bedrock being close to the soil surface of the shallow plots.

  13. Effect of day length on germination of seeds collected in Alaska

    USGS Publications Warehouse

    Densmore, R.V.

    1997-01-01

    Day length control can effectively limit seed germination to favorable seasons, but this phenomenon has been studied in relatively few wild plants. I tested species from interior Alaska for day length control of germination under controlled conditions, and I also monitored germination phenology in natural habitats. Unstratified and cold-stratified seeds were germinated on short (13 h) and long (22 h) day length and in the dark at constant and alternating temperatures. On long day length, unstratified Ledum decumbens and Saxifraga tricuspidata seeds germinated from 5??C to 20??C, but on short day length few or no seeds germinated at 5??C and 10??C and germination was reduced at higher temperatures. Unstratified seeds of Diapensia lapponica and Chamaedaphne calyculata germinated only at 15??C and 20??C on long day length, and short day length completely inhibited germination. Cold stratification widened the temperature range for germination on both long and short day lengths, but germination was still lower on short than long day length. Germination phenology in natural habitats was consistent with germination in controlled conditions. In these species, short day length and low temperatures interact to inhibit germination in the fall. After overwintering, seeds germinate in the spring at low temperatures and on long day lengths. The inhibitory effect of short day length is not important in the spring because day length is already long at snowmelt.

  14. Seed germination of Sierra Nevada postfire chaparral species

    USGS Publications Warehouse

    Keeley, Jon E.; McGinnis, Thomas W.; Bollens, Kim A.

    2005-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Here we report further germination experiments that elucidate the response of several widespread shrub species whose germination response was not clear and include other species from the Sierra Nevada, which have not previously been included in germination studies. The shrubs Adenostoma fasciculatum and Eriodictyon crassifolium and the postfire annualMentzelia dispersa exhibited highly significant germination in response to smoke treatments, with some enhanced germination in response to heating as well. The shrubs Fremontodendron californicum and Malacothamnus fremontii were stimulated only by heat-shock treatments. Seeds buried in the soil for one year exhibited substantially higher germination for controls and most treatments. In the case of two postfire annuals, Mimulus bolanderi and M. gracilipes, germination of fresh seed was significantly greater with smoke or heating but after soil storage, over two-thirds of the control seeds germinated and treatment effects were not significant. These two annuals are generally restricted to postfire conditions and it is suggested that control germination of soil-stored seed may be a light-response (which was not tested here) as previously reported for another chaparral species in that genus.

  15. Evidence that the attentional set shifting test in rats can be applied in repeated testing paradigms.

    PubMed

    Wallace, J; Marston, H M; McQuade, R; Gartside, S E

    2014-07-01

    The attentional set shifting task (ASST) can be used to assess aspects of executive function, including reversal learning and set shifting. It has frequently been employed in between-subjects experimental designs: however, the clear advantages of within-subjects designs (reduction in variance, animal numbers, and cost) mean that investigation of the suitability of the ASST for within subjects designs is warranted. Rats were tested three times: test 1 (24 h after training), test 2 (24 h later), and test 3 (seven days later). On all three test days, animals showed the expected pattern of performance across the seven task stages with evidence of normal reversal learning (significant increase in trials to criterion when the rule was reversed) and intact set formation (significantly more trials to criterion for an extradimensional shift than for an intradimensional shift). There was a small decrease in total trials required to complete the task between test 1 and test 3 but this was not specific to any stage of the task. Latency to dig decreased on repeated testing suggesting some facilitation of associative learning. In conclusion, the rodent ASST is suitable for within-subject design longitudinal studies, increasing the utility and the translational value of this test and reducing numbers of animals needed in studies.

  16. Pre-germinated conidia of Coniothyrium minitans enhances the foliar biological control of Sclerotinia sclerotiorum.

    PubMed

    Shi, Junling; Li, Yin; Qian, Huali; Du, Guocheng; Chen, Jian

    2004-11-01

    The relatively slow germination rate of Coniothyrium minitans limits its control efficiency against Sclerotinia sclerotiorum. Pre-germinated conidia of C. minitans enhanced its efficiency significantly: in foliar experiments with oilseed rape, hyphal extension of S. sclerotiorum was inhibited by 68%, while formation of sclerotia was completely inhibited when pre-germinated conidia were applied.

  17. Pre-germinated conidia of Coniothyrium minitans enhances the foliar biological control of Sclerotinia sclerotiorum.

    PubMed

    Shi, Junling; Li, Yin; Qian, Huali; Du, Guocheng; Chen, Jian

    2004-11-01

    The relatively slow germination rate of Coniothyrium minitans limits its control efficiency against Sclerotinia sclerotiorum. Pre-germinated conidia of C. minitans enhanced its efficiency significantly: in foliar experiments with oilseed rape, hyphal extension of S. sclerotiorum was inhibited by 68%, while formation of sclerotia was completely inhibited when pre-germinated conidia were applied. PMID:15604814

  18. Effects of Seed Cryopreservation and Priming on Germination in Several Cultivars of Apium graveolens.

    PubMed

    Gonzalez-Benito, M E; Iriondo, J M; Pita, J M; Pérez-García, F

    1995-01-01

    Seed germination of seven celery cultivars was studied after storage in liquid nitrogen for 1 or 30 d. Cryopreservation was also carried out on pelleted and primed seeds. None of the treatments applied reduced germination percentages. T(50) (time for germination to reach 50%) significantly decreased in Florida, Utah and Istar cultivars when priming, alone or in combination with cryopreservation, was used.

  19. 40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... cycle statistics and compare with the established criteria as specified in 40 CFR 1065.514 to confirm... 40 Protection of Environment 34 2013-07-01 2013-07-01 false What transient duty cycles apply for... Procedures § 1048.510 What transient duty cycles apply for laboratory testing? (a) Starting with the...

  20. 40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... cycle statistics and compare with the established criteria as specified in 40 CFR 1065.514 to confirm... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What transient duty cycles apply for... Procedures § 1048.510 What transient duty cycles apply for laboratory testing? (a) Starting with the...

  1. 40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... cycle statistics and compare with the established criteria as specified in 40 CFR 1065.514 to confirm... 40 Protection of Environment 33 2014-07-01 2014-07-01 false What transient duty cycles apply for... Procedures § 1048.510 What transient duty cycles apply for laboratory testing? (a) Starting with the...

  2. 40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cycle statistics and compare with the established criteria as specified in 40 CFR 1065.514 to confirm... 40 Protection of Environment 34 2012-07-01 2012-07-01 false What transient duty cycles apply for... Procedures § 1048.510 What transient duty cycles apply for laboratory testing? (a) Starting with the...

  3. 40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cycle statistics and compare with the established criteria as specified in 40 CFR 1065.514 to confirm... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What transient duty cycles apply for... Procedures § 1048.510 What transient duty cycles apply for laboratory testing? (a) Starting with the...

  4. Applied Physics Modules: Notes, Instructions, Data Sheets, Tests, and Test Answer Keys.

    ERIC Educational Resources Information Center

    Southeast Community Coll., Lincoln, NE.

    These user instructions and related materials are designed to accompany a series of twenty-three applied physics modules which have been developed for postsecondary students in electrical, electronics, machine tool, metals, manufacturing, automotive, diesel, architecture, and civil drafting occupational programs. The instructions include an…

  5. The mechanism underlying fast germination of tomato cultivar LA2711.

    PubMed

    Yang, Rongchao; Chu, Zhuannan; Zhang, Haijun; Li, Ying; Wang, Jinfang; Li, Dianbo; Weeda, Sarah; Ren, Shuxin; Ouyang, Bo; Guo, Yang-Dong

    2015-09-01

    Seed germination is important for early plant morphogenesis as well as abiotic stress tolerance, and is mainly controlled by the phytohormones abscisic acid (ABA) and gibberellic acid (GA). Our previous studies identified a salt-tolerant tomato cultivar, LA2711, which is also a fast-germinating genotype, compared to its salt-sensitive counterpart, ZS-5. In an effort to further clarify the mechanism underlying this phenomenon, we compared the dynamic levels of ABA and GA4, the transcript abundance of genes involved in their biosynthesis and catabolism as well as signal transduction between the two cultivars. In addition, we tested seed germination sensitivity to ABA and GAs. Our results revealed that insensitivity of seed germination to exogenous ABA and low ABA content in seeds are the physiological mechanisms conferring faster germination rates of LA2711 seeds. SlCYP707A2, which encodes an ABA catabolic enzyme, may play a decisive role in the fast germination rate of LA2711, as it showed a significantly higher level of expression in LA2711 than ZS-5 at most time points tested during germination. The current results will enable us to gain insight into the mechanism(s) regarding seed germination of tomato and the role of fast germination in stress tolerance.

  6. Engineering in software testing: statistical testing based on a usage model applied to medical device development.

    PubMed

    Jones, P L; Swain, W T; Trammell, C J

    1999-01-01

    When a population is too large for exhaustive study, as is the case for all possible uses of a software system, a statistically correct sample must be drawn as a basis for inferences about the population. A Markov chain usage model is an engineering formalism that represents the population of possible uses for which a product is to be tested. In statistical testing of software based on a Markov chain usage model, the rich body of analytical results available for Markov chains provides numerous insights that can be used in both product development and test planing. A usage model is based on specifications rather than code, so insights that result from model building can inform product decisions in the early stages of a project when the opportunity to prevent problems is the greatest. Statistical testing based on a usage model provides a sound scientific basis for quantifying the reliability of software. PMID:10459417

  7. A Multivariate Randomization Text of Association Applied to Cognitive Test Results

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert; Beard, Bettina

    2009-01-01

    Randomization tests provide a conceptually simple, distribution-free way to implement significance testing. We have applied this method to the problem of evaluating the significance of the association among a number (k) of variables. The randomization method was the random re-ordering of k-1 of the variables. The criterion variable was the value of the largest eigenvalue of the correlation matrix.

  8. 77 FR 73401 - Not Applying the Mark of Inspection Pending Certain Test Results

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ..., ``Not Applying the Mark of Inspection Pending Certain Test Results'' (76 FR 19952). The notice explained... residues, such product would not need to be held from commerce pending negative test results (76 FR 19955... the lot under company seal (76 FR 19955). The commenters stated that FSIS should not prescribe...

  9. LPT. Shield test facility (TAN646) interior. Construction worker applies caulking ...

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

    LPT. Shield test facility (TAN-646) interior. Construction worker applies caulking compound to joint between stainless steel weir and concrete. Photographer: Jack L. Anderson. Date: March 6, 1959. INEEL negative no. 59-1099 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  10. Mapping Interactions between Germinants and Clostridium difficile Spores ▿

    PubMed Central

    Howerton, Amber; Ramirez, Norma; Abel-Santos, Ernesto

    2011-01-01

    Germination of Clostridium difficile spores is the first required step in establishing C. difficile-associated disease (CDAD). Taurocholate (a bile salt) and glycine (an amino acid) have been shown to be important germinants of C. difficile spores. In the present study, we tested a series of glycine and taurocholate analogs for the ability to induce or inhibit C. difficile spore germination. Testing of glycine analogs revealed that both the carboxy and amino groups are important epitopes for recognition and that the glycine binding site can accommodate compounds with more widely separated termini. The C. difficile germination machinery also recognizes other hydrophobic amino acids. In general, linear alkyl side chains are better activators of spore germination than their branched analogs. However, l-phenylalanine and l-arginine are also good germinants and are probably recognized by distinct binding sites. Testing of taurocholate analogs revealed that the 12-hydroxyl group of taurocholate is necessary, but not sufficient, to activate spore germination. In contrast, the 6- and 7-hydroxyl groups are required for inhibition of C. difficile spore germination. Similarly, C. difficile spores are able to detect taurocholate analogs with shorter, but not longer, alkyl amino sulfonic acid side chains. Furthermore, the sulfonic acid group can be partially substituted with other acidic groups. Finally, a taurocholate analog with an m-aminobenzenesulfonic acid side chain is a strong inhibitor of C. difficile spore germination. In conclusion, C. difficile spores recognize both amino acids and taurocholate through multiple interactions that are required to bind the germinants and/or activate the germination machinery. PMID:20971909

  11. Applying EVM to Satellite on Ground and In-Orbit Testing - Better Data in Less Time

    NASA Technical Reports Server (NTRS)

    Peters, Robert; Lebbink, Elizabeth-Klein; Lee, Victor; Model, Josh; Wezalis, Robert; Taylor, John

    2008-01-01

    Using Error Vector Magnitude (EVM) in satellite integration and test allows rapid verification of the Bit Error Rate (BER) performance of a satellite link and is particularly well suited to measurement of low bit rate satellite links where it can result in a major reduction in test time (about 3 weeks per satellite for the Geosynchronous Operational Environmental Satellite [GOES] satellites during ground test) and can provide diagnostic information. Empirical techniques developed to predict BER performance from EVM measurements and lessons learned about applying these techniques during GOES N, O, and P integration test and post launch testing, are discussed.

  12. Seed Dormancy and Germination

    PubMed Central

    Bentsink, Leónie; Koornneef, Maarten

    2008-01-01

    Seed dormancy allows seeds to overcome periods that are unfavourable for seedling established and is therefore important for plant ecology and agriculture. Several processes are known to be involved in the induction of dormancy and in the switch from the dormant to the germinating state. The role of plant hormones, the different tissues and genes involved, including newly identified genes in dormancy and germination are described in this chapter, as well as the use transcriptome, proteome and metabolome analyses to study these mechanistically not well understood processes. PMID:22303244

  13. Involvement of Coat Proteins in Bacillus subtilis Spore Germination in High-Salinity Environments

    PubMed Central

    Nagler, Katja; Setlow, Peter; Reineke, Kai; Driks, Adam

    2015-01-01

    The germination of spore-forming bacteria in high-salinity environments is of applied interest for food microbiology and soil ecology. It has previously been shown that high salt concentrations detrimentally affect Bacillus subtilis spore germination, rendering this process slower and less efficient. The mechanistic details of these salt effects, however, remained obscure. Since initiation of nutrient germination first requires germinant passage through the spores' protective integuments, the aim of this study was to elucidate the role of the proteinaceous spore coat in germination in high-salinity environments. Spores lacking major layers of the coat due to chemical decoating or mutation germinated much worse in the presence of NaCl than untreated wild-type spores at comparable salinities. However, the absence of the crust, the absence of some individual nonmorphogenetic proteins, and the absence of either CwlJ or SleB had no or little effect on germination in high-salinity environments. Although the germination of spores lacking GerP (which is assumed to facilitate germinant flow through the coat) was generally less efficient than the germination of wild-type spores, the presence of up to 2.4 M NaCl enhanced the germination of these mutant spores. Interestingly, nutrient-independent germination by high pressure was also inhibited by NaCl. Taken together, these results suggest that (i) the coat has a protective function during germination in high-salinity environments; (ii) germination inhibition by NaCl is probably not exerted at the level of cortex hydrolysis, germinant accessibility, or germinant-receptor binding; and (iii) the most likely germination processes to be inhibited by NaCl are ion, Ca2+-dipicolinic acid, and water fluxes. PMID:26187959

  14. Involvement of Coat Proteins in Bacillus subtilis Spore Germination in High-Salinity Environments.

    PubMed

    Nagler, Katja; Setlow, Peter; Reineke, Kai; Driks, Adam; Moeller, Ralf

    2015-10-01

    The germination of spore-forming bacteria in high-salinity environments is of applied interest for food microbiology and soil ecology. It has previously been shown that high salt concentrations detrimentally affect Bacillus subtilis spore germination, rendering this process slower and less efficient. The mechanistic details of these salt effects, however, remained obscure. Since initiation of nutrient germination first requires germinant passage through the spores' protective integuments, the aim of this study was to elucidate the role of the proteinaceous spore coat in germination in high-salinity environments. Spores lacking major layers of the coat due to chemical decoating or mutation germinated much worse in the presence of NaCl than untreated wild-type spores at comparable salinities. However, the absence of the crust, the absence of some individual nonmorphogenetic proteins, and the absence of either CwlJ or SleB had no or little effect on germination in high-salinity environments. Although the germination of spores lacking GerP (which is assumed to facilitate germinant flow through the coat) was generally less efficient than the germination of wild-type spores, the presence of up to 2.4 M NaCl enhanced the germination of these mutant spores. Interestingly, nutrient-independent germination by high pressure was also inhibited by NaCl. Taken together, these results suggest that (i) the coat has a protective function during germination in high-salinity environments; (ii) germination inhibition by NaCl is probably not exerted at the level of cortex hydrolysis, germinant accessibility, or germinant-receptor binding; and (iii) the most likely germination processes to be inhibited by NaCl are ion, Ca(2+)-dipicolinic acid, and water fluxes. PMID:26187959

  15. Cost effectiveness as applied to the Viking Lander systems-level thermal development test program

    NASA Technical Reports Server (NTRS)

    Buna, T.; Shupert, T. C.

    1974-01-01

    The economic aspects of thermal testing at the systems-level as applied to the Viking Lander Capsule thermal development program are reviewed. The unique mission profile and pioneering scientific goals of Viking imposed novel requirements on testing, including the development of a simulation technique for the Martian thermal environment. The selected approach included modifications of an existing conventional thermal vacuum facility, and improved test-operational techniques that are applicable to the simulation of the other mission phases as well, thereby contributing significantly to the cost effectiveness of the overall thermal test program.

  16. Germination of Candida albicans induced by proline.

    PubMed Central

    Dabrowa, N; Taxer, S S; Howard, D H

    1976-01-01

    Blastospores of Candida albicans germinated in proline-biotin-buffer medium incubated at 37 C. Certain other amino acids in the glatamate, asparate, and pyruvate families also fostered germinaton but generally to a lesser extent than did proline. L-Cysteine, D-proline, and certain structural analogues of L-proline inhibited proline-stimualted germination. The concentration of phosphate and glucose was crucial to amino acid-stimulated germination of C. albicans. Clinical isolates and stock cultures varied in their response to the germ tube-inducing activity of proline or other amino acids. The proline-buffer medium cannot be used in a diagnostic test for production of germ tubes by isolates of yeasts. PMID:5375

  17. Model-based testing with UML applied to a roaming algorithm for bluetooth devices.

    PubMed

    Dai, Zhen Ru; Grabowski, Jens; Neukirchen, Helmut; Pals, Holger

    2004-11-01

    In late 2001, the Object Management Group issued a Request for Proposal to develop a testing profile for UML 2.0. In June 2003, the work on the UML 2.0 Testing Profile was finally adopted by the OMG. Since March 2004, it has become an official standard of the OMG. The UML 2.0 Testing Profile provides support for UML based model-driven testing. This paper introduces a methodology on how to use the testing profile in order to modify and extend an existing UML design model for test issues. The application of the methodology will be explained by applying it to an existing UML Model for a Bluetooth device.

  18. Applying Specific Information Item Selection to a Passage-Based Test.

    ERIC Educational Resources Information Center

    Thompson, Tony D.; Davey, Tim

    This paper applies specific information item selection using a method developed by T. Davey and M. Fan (2000) to a multiple-choice passage-based reading test that is being developed for computer administration. Data used to calibrate the multidimensional item parameters for the simulation study consisted of item responses from randomly equivalent…

  19. Thermal nondestructive testing (TNDT) of adhesively bonded composite reinforcements applied to concrete civil structures

    NASA Astrophysics Data System (ADS)

    Burleigh, Douglas D.; Bohner, Richard

    1999-02-01

    Thermographic nondestructive testing was performed on composite reinforcements applied to two concrete civil structures. Information on the types of defects which occur in these structures and their locations has led to process improvements in the application of adhesively bonded laminated composites to steel reinforce concrete structures.

  20. Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes.

    PubMed

    Lone, A B; Colombo, R C; Andrade, B L G; Takahashi, L S A; Faria, R T

    2016-06-01

    The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

  1. Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes.

    PubMed

    Lone, A B; Colombo, R C; Andrade, B L G; Takahashi, L S A; Faria, R T

    2016-06-01

    The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable. PMID:26934150

  2. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... separation of the kind, variety, or type considered pure seed and shall be counted without discrimination as to size or appearance. (b) When only a germination test is required and the pure seed is estimated...

  3. Case Studies for the Statistical Design of Experiments Applied to Powered Rotor Wind Tunnel Tests

    NASA Technical Reports Server (NTRS)

    Overmeyer, Austin D.; Tanner, Philip E.; Martin, Preston B.; Commo, Sean A.

    2015-01-01

    The application of statistical Design of Experiments (DOE) to helicopter wind tunnel testing was explored during two powered rotor wind tunnel entries during the summers of 2012 and 2013. These tests were performed jointly by the U.S. Army Aviation Development Directorate Joint Research Program Office and NASA Rotary Wing Project Office, currently the Revolutionary Vertical Lift Project, at NASA Langley Research Center located in Hampton, Virginia. Both entries were conducted in the 14- by 22-Foot Subsonic Tunnel with a small portion of the overall tests devoted to developing case studies of the DOE approach as it applies to powered rotor testing. A 16-47 times reduction in the number of data points required was estimated by comparing the DOE approach to conventional testing methods. The average error for the DOE surface response model for the OH-58F test was 0.95 percent and 4.06 percent for drag and download, respectively. The DOE surface response model of the Active Flow Control test captured the drag within 4.1 percent of measured data. The operational differences between the two testing approaches are identified, but did not prevent the safe operation of the powered rotor model throughout the DOE test matrices.

  4. Pre-treating Seed to Enhance Germination of Desert Shrubs

    SciTech Connect

    W. K. Ostler; D. C. Anderson; D. J. Hansen

    2002-06-01

    Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.

  5. Microstrain-level measurement of third-order elastic constants applying dynamic acousto-elastic testing

    NASA Astrophysics Data System (ADS)

    Renaud, Guillaume; Talmant, Maryline; Marrelec, Guillaume

    2016-10-01

    The nonlinear elasticity of solids at the microstrain level has been recently studied by applying dynamic acousto-elastic testing. It is the analog of conventional quasi-static acousto-elastic experiments but the strain-dependence (or stress-dependence) of ultrasonic wave-speed is measured with an applied strain ranging from 10-7 to 10-5 and produced by a stationary elastic wave. In conventional quasi-static acousto-elastic experiments, the strain is applied in a quasi-static manner; it exceeds 10-4 and can reach 10-2. In this work, we apply dynamic acousto-elastic testing to measure the third-order elastic constants of two isotropic materials: polymethyl methacrylate and dry Berea sandstone. The peak amplitude of the dynamic applied strain is 8 × 10-6. The method is shown to be particularly suitable for materials exhibiting large elastic nonlinearity like sandstones, since the measurement is performed in the domain of validity of the third-order hyperelastic model. In contrast, conventional quasi-static acousto-elastic experiments in such materials are often performed outside the domain of validity of the third-order hyperelastic model and the stress-dependence of the ultrasonic wave-speed must be extrapolated at zero stress, leading to approximate values of the third-order elastic constants. The uncertainty of the evaluation of the third-order elastic constants is assessed by repeating multiple times the measurements and with Monte-Carlo simulations. The obtained values of the Murnaghan third-order elastic constants are l = -73 GPa ± 9%, m = -34 GPa ± 9%, and n = -61 GPa ± 10% for polymethyl methacrylate, and l = -17 000 GPa ± 20%, m = -11 000 GPa ± 10%, and n = -30 000 GPa ± 20% for dry Berea sandstone.

  6. Effects of germination season on life history traits and on transgenerational plasticity in seed dormancy in a cold desert annual.

    PubMed

    Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

    2016-01-01

    The maternal environment can influence the intensity of seed dormancy and thus seasonal germination timing and post-germination life history traits. We tested the hypotheses that germination season influences phenotypic expression of post-germination life history traits in the cold desert annual Isatis violascens and that plants from autumn- and spring-germinating seeds produce different proportions of seeds with nondeep and intermediate physiological dormancy (PD). Seeds were sown in summer and flexibility in various life history traits determined for plants that germinated in autumn and in spring. A higher percentage of spring- than of autumn-germinating plants survived the seedling stage, and all surviving plants reproduced. Number of silicles increased with plant size (autumn- > spring-germinating plants), whereas percent dry mass allocated to reproduction was higher in spring- than in autumn-germinating plants. Autumn-germinating plants produced proportionally more seeds with intermediate PD than spring-germinating plants, while spring-germinating plants produced proportionally more seeds with nondeep PD than autumn-germinating plants. Flexibility throughout the life history and transgenerational plasticity in seed dormancy are adaptations of I. violascens to its desert habitat. Our study is the first to demonstrate that autumn- and spring-germinating plants in a species population differ in proportion of seeds produced with different levels of PD.

  7. Effects of germination season on life history traits and on transgenerational plasticity in seed dormancy in a cold desert annual

    PubMed Central

    Lu, Juan J.; Tan, Dun Y.; Baskin, Carol C.; Baskin, Jerry M.

    2016-01-01

    The maternal environment can influence the intensity of seed dormancy and thus seasonal germination timing and post-germination life history traits. We tested the hypotheses that germination season influences phenotypic expression of post-germination life history traits in the cold desert annual Isatis violascens and that plants from autumn- and spring-germinating seeds produce different proportions of seeds with nondeep and intermediate physiological dormancy (PD). Seeds were sown in summer and flexibility in various life history traits determined for plants that germinated in autumn and in spring. A higher percentage of spring- than of autumn-germinating plants survived the seedling stage, and all surviving plants reproduced. Number of silicles increased with plant size (autumn- > spring-germinating plants), whereas percent dry mass allocated to reproduction was higher in spring- than in autumn-germinating plants. Autumn-germinating plants produced proportionally more seeds with intermediate PD than spring-germinating plants, while spring-germinating plants produced proportionally more seeds with nondeep PD than autumn-germinating plants. Flexibility throughout the life history and transgenerational plasticity in seed dormancy are adaptations of I. violascens to its desert habitat. Our study is the first to demonstrate that autumn- and spring-germinating plants in a species population differ in proportion of seeds produced with different levels of PD. PMID:27117090

  8. Impact of gene patents on diagnostic testing: a new patent landscaping method applied to spinocerebellar ataxia

    PubMed Central

    Berthels, Nele; Matthijs, Gert; Van Overwalle, Geertrui

    2011-01-01

    Recent reports in Europe and the United States raise concern about the potential negative impact of gene patents on the freedom to operate of diagnosticians and on the access of patients to genetic diagnostic services. Patents, historically seen as legal instruments to trigger innovation, could cause undesired side effects in the public health domain. Clear empirical evidence on the alleged hindering effect of gene patents is still scarce. We therefore developed a patent categorization method to determine which gene patents could indeed be problematic. The method is applied to patents relevant for genetic testing of spinocerebellar ataxia (SCA). The SCA test is probably the most widely used DNA test in (adult) neurology, as well as one of the most challenging due to the heterogeneity of the disease. Typically tested as a gene panel covering the five common SCA subtypes, we show that the patenting of SCA genes and testing methods and the associated licensing conditions could have far-reaching consequences on legitimate access to this gene panel. Moreover, with genetic testing being increasingly standardized, simply ignoring patents is unlikely to hold out indefinitely. This paper aims to differentiate among so-called ‘gene patents' by lifting out the truly problematic ones. In doing so, awareness is raised among all stakeholders in the genetic diagnostics field who are not necessarily familiar with the ins and outs of patenting and licensing. PMID:21811306

  9. CR-Calculus and adaptive array theory applied to MIMO random vibration control tests

    NASA Astrophysics Data System (ADS)

    Musella, U.; Manzato, S.; Peeters, B.; Guillaume, P.

    2016-09-01

    Performing Multiple-Input Multiple-Output (MIMO) tests to reproduce the vibration environment in a user-defined number of control points of a unit under test is necessary in applications where a realistic environment replication has to be achieved. MIMO tests require vibration control strategies to calculate the required drive signal vector that gives an acceptable replication of the target. This target is a (complex) vector with magnitude and phase information at the control points for MIMO Sine Control tests while in MIMO Random Control tests, in the most general case, the target is a complete spectral density matrix. The idea behind this work is to tailor a MIMO random vibration control approach that can be generalized to other MIMO tests, e.g. MIMO Sine and MIMO Time Waveform Replication. In this work the approach is to use gradient-based procedures over the complex space, applying the so called CR-Calculus and the adaptive array theory. With this approach it is possible to better control the process performances allowing the step-by-step Jacobian Matrix update. The theoretical bases behind the work are followed by an application of the developed method to a two-exciter two-axis system and by performance comparisons with standard methods.

  10. Mechanisms of glucose signaling during germination of Arabidopsis.

    PubMed

    Price, John; Li, Tsai-Chi; Kang, Shin Gene; Na, Jong Kuk; Jang, Jyan-Chyun

    2003-07-01

    Glucose (Glc) signaling, along with abscisic acid (ABA) signaling, has been implicated in regulating early plant development in Arabidopsis. It is generally believed that high levels of exogenous Glc cause ABA accumulation, which results in a delay of germination and an inhibition of seedling development-a typical stress response. To test this hypothesis and decipher the complex interactions that occur in the signaling pathways, we determined the effects of sugar and ABA on one developmental event, germination. We show that levels of exogenous Glc lower than previously cited could delay the rate of seed germination in wild-ecotype seeds. Remarkably, this effect could not be mimicked by an osmotic effect, and ABA was still involved. With higher concentrations of Glc, previously known Glc-insensitive mutants gin2 and abi4 exhibited germination kinetics similar to wild type, indicating that Glc-insensitive phenotypes are not the same for all developmental stages of growth and that the signaling properties of Glc vary with concentration. Higher concentrations of Glc were more potent in delaying seed germination. However, Glc-delayed seed germination was not caused by increased cellular ABA concentration, rather Glc appeared to slow down the decline of endogenous ABA. Except for the ABA-insensitive mutants, all tested genotypes appeared to have similar ABA perception during germination, where germination was correlated with the timing of ABA drop to a threshold level. In addition, Glc was found to modulate the transcription of genes involved in ABA biosynthesis and perception only after germination, suggesting a critical role of the developmental program in sugar sensing. On the basis of an extensive phenotypic, biochemical, and molecular analysis, we suggest that exogenous Glc application creates specific signals that vary with concentration and the developmental stage of the plant and that Glc-induced fluctuations in endogenous ABA level generate a different set of

  11. Tank Applied Testing of Load-Bearing Multilayer Insulation (LB-MLI)

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Valenzuela, Juan G.; Feller, Jerr; Plachta, Dave

    2014-01-01

    The development of long duration orbital cryogenic storage systems will require the reduction of heat loads into the storage tank. In the case of liquid hydrogen, complete elimination of the heat load at 20 K is currently impractical due to the limitations in lift available on flight cryocoolers. In order to reduce the heat load, without having to remove heat at 20 K, the concept of Reduced Boil-Off uses cooled shields within the insulation system at approximately 90 K. The development of Load-Bearing Multilayer Insulation (LB-MLI) allowed the 90 K shield with tubing and cryocooler attachments to be suspended within the MLI and still be structurally stable. Coupon testing both thermally and structurally were performed to verify that the LB-MLI should work at the tank applied level. Then tank applied thermal and structural (acoustic) testing was performed to demonstrate the functionality of the LB-MLI as a structural insulation system. The LB-MLI showed no degradation of thermal performance due to the acoustic testing and showed excellent thermal performance when integrated with a 90 K class cryocooler on a liquid hydrogen tank.

  12. Tank Applied Testing of Load-Bearing Multilayer Insulation (LB-MLI)

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Valenzuela, Juan G.; Feller, Jeffrey R.; Plachta, David W.

    2014-01-01

    The development of long duration orbital cryogenic storage systems will require the reduction of heat loads into the storage tank. In the case of liquid hydrogen, complete elimination of the heat load at 20 K is currently impractical due to the limitations in lift available on flight cryocoolers. In order to reduce the heat load, without having to remove heat at 20 K, the concept of Reduced Boil-Off uses cooled shields within the insulation system at approximately 90 K. The development of Load-Bearing Multilayer Insulation (LB-MLI) allowed the 90 K shield with tubing and cryocooler attachments to be suspended within the MLI and still be structurally stable. Coupon testing, both thermal and structural was performed to verify that the LB-MLI should work at the tank applied level. Then tank applied thermal and structural (acoustic) testing was performed to demonstrate the functionality of the LB-MLI as a structural insulation system. The LB-MLI showed no degradation of thermal performance due to the acoustic testing and showed excellent thermal performance when integrated with a 90 K class cryocooler on a liquid hydrogen tank.

  13. Treatments affecting maturation and germination of American chestnut somatic embryos.

    PubMed

    Robichaud, Rodney L; Lessard, Veronica C; Merkle, Scott A

    2004-08-01

    The effects of amino acids, abscisic acid (ABA), polyethylene glycol (PEG), and elevated sucrose were tested on the maturation and germination of American chestnut (Castanea dentata) somatic embryos. Somatic embryos from three lines were matured over an eight week period through a two-stage process. After maturation, somatic embryos were randomly divided into three groups to measure dry weight/ fresh weight ratios, starch levels, and germination rates. Prior to transfer to germination medium, somatic embryos received a four week cold treatment. While some treatments with amino acids, elevated sucrose, PEG or ABA increased either dry weight/fresh weight ratios, starch content or both, only addition of 25mM L-asparagine significantly increased germination rate and taproot length, and this response was only obtained with one of the three lines tested. Six plants survived the transfer to potting mix, acclimatization to greenhouse conditions and field planting. PMID:15384407

  14. Treatments affecting maturation and germination of American chestnut somatic embryos.

    PubMed

    Robichaud, Rodney L; Lessard, Veronica C; Merkle, Scott A

    2004-08-01

    The effects of amino acids, abscisic acid (ABA), polyethylene glycol (PEG), and elevated sucrose were tested on the maturation and germination of American chestnut (Castanea dentata) somatic embryos. Somatic embryos from three lines were matured over an eight week period through a two-stage process. After maturation, somatic embryos were randomly divided into three groups to measure dry weight/ fresh weight ratios, starch levels, and germination rates. Prior to transfer to germination medium, somatic embryos received a four week cold treatment. While some treatments with amino acids, elevated sucrose, PEG or ABA increased either dry weight/fresh weight ratios, starch content or both, only addition of 25mM L-asparagine significantly increased germination rate and taproot length, and this response was only obtained with one of the three lines tested. Six plants survived the transfer to potting mix, acclimatization to greenhouse conditions and field planting.

  15. Cortaderia selloana seed germination under different ecological conditions

    NASA Astrophysics Data System (ADS)

    Domènech, Roser; Vilà, Montserrat

    2008-01-01

    iological invasions are causing the extinction of native species and modifying ecosystem functions. Invasion success depends, among other factors, on the biological attributes of the invaders and the abiotic characteristics of the recipient community. Cortaderia selloana is a gynodioecious perennial grass native to South America which is considered invasive worldwide. It is known that seedlings of this species tolerate a wide range of environmental conditions. However, the abiotic factors that may favour its seed germination have not been studied in much detail. For this reason, we conducted an array of germination tests with different degrees of shading, soil textures and water availability. Although C. selloana usually grows in disturbed sites where light is highly available, we found that seed germination was higher under shaded conditions than under 100% light. Seed germination was higher in sandy soil textures and decreased in soils which contained increased levels of clay. Mature C. selloana plants have been reported to tolerate water stress, yet we found that the shortage of water availability constrained seed germination to approximately 60%. Overall, C. selloana seeds seem to germinate under a wide range of environmental conditions, yet germination rate can be improved under shading, high levels of sand and with high water availability.

  16. Disentangling manual muscle testing and Applied Kinesiology: critique and reinterpretation of a literature review.

    PubMed

    Haas, Mitchell; Cooperstein, Robert; Peterson, David

    2007-01-01

    Cuthbert and Goodheart recently published a narrative review on the reliability and validity of manual muscle testing (MMT) in the Journal. The authors should be recognized for their effort to synthesize this vast body of literature. However, the review contains critical errors in the search methods, inclusion criteria, quality assessment, validity definitions, study interpretation, literature synthesis, generalizability of study findings, and conclusion formulation that merit a reconsideration of the authors' findings. Most importantly, a misunderstanding of the review could easily arise because the authors did not distinguish the general use of muscle strength testing from the specific applications that distinguish the Applied Kinesiology (AK) chiropractic technique. The article makes the fundamental error of implying that the reliability and validity of manual muscle testing lends some degree of credibility to the unique diagnostic procedures of AK. The purpose of this commentary is to provide a critical appraisal of the review, suggest conclusions consistent with the literature both reviewed and omitted, and extricate conclusions that can be made about AK in particular from those that can be made about MMT. When AK is disentangled from standard orthopedic muscle testing, the few studies evaluating unique AK procedures either refute or cannot support the validity of AK procedures as diagnostic tests. The evidence to date does not support the use of MMT for the diagnosis of organic disease or pre/subclinical conditions.

  17. Clinical usefulness of the clock drawing test applying rasch analysis in predicting of cognitive impairment.

    PubMed

    Yoo, Doo Han; Lee, Jae Shin

    2016-07-01

    [Purpose] This study examined the clinical usefulness of the clock drawing test applying Rasch analysis for predicting the level of cognitive impairment. [Subjects and Methods] A total of 187 stroke patients with cognitive impairment were enrolled in this study. The 187 patients were evaluated by the clock drawing test developed through Rasch analysis along with the mini-mental state examination of cognitive evaluation tool. An analysis of the variance was performed to examine the significance of the mini-mental state examination and the clock drawing test according to the general characteristics of the subjects. Receiver operating characteristic analysis was performed to determine the cutoff point for cognitive impairment and to calculate the sensitivity and specificity values. [Results] The results of comparison of the clock drawing test with the mini-mental state showed significant differences in according to gender, age, education, and affected side. A total CDT of 10.5, which was selected as the cutoff point to identify cognitive impairement, showed a sensitivity, specificity, Youden index, positive predictive, and negative predicive values of 86.4%, 91.5%, 0.8, 95%, and 88.2%. [Conclusion] The clock drawing test is believed to be useful in assessments and interventions based on its excellent ability to identify cognitive disorders.

  18. Clinical usefulness of the clock drawing test applying rasch analysis in predicting of cognitive impairment

    PubMed Central

    Yoo, Doo Han; Lee, Jae Shin

    2016-01-01

    [Purpose] This study examined the clinical usefulness of the clock drawing test applying Rasch analysis for predicting the level of cognitive impairment. [Subjects and Methods] A total of 187 stroke patients with cognitive impairment were enrolled in this study. The 187 patients were evaluated by the clock drawing test developed through Rasch analysis along with the mini-mental state examination of cognitive evaluation tool. An analysis of the variance was performed to examine the significance of the mini-mental state examination and the clock drawing test according to the general characteristics of the subjects. Receiver operating characteristic analysis was performed to determine the cutoff point for cognitive impairment and to calculate the sensitivity and specificity values. [Results] The results of comparison of the clock drawing test with the mini-mental state showed significant differences in according to gender, age, education, and affected side. A total CDT of 10.5, which was selected as the cutoff point to identify cognitive impairement, showed a sensitivity, specificity, Youden index, positive predictive, and negative predicive values of 86.4%, 91.5%, 0.8, 95%, and 88.2%. [Conclusion] The clock drawing test is believed to be useful in assessments and interventions based on its excellent ability to identify cognitive disorders. PMID:27512283

  19. Two self-test methods applied to an inertial system problem. [estimating gyroscope and accelerometer bias

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.; Deyst, J. J.; Crawford, B. S.

    1975-01-01

    The paper describes two self-test procedures applied to the problem of estimating the biases in accelerometers and gyroscopes on an inertial platform. The first technique is the weighted sum-squared residual (WSSR) test, with which accelerator bias jumps are easily isolated, but gyro bias jumps are difficult to isolate. The WSSR method does not take full advantage of the knowledge of system dynamics. The other technique is a multiple hypothesis method developed by Buxbaum and Haddad (1969). It has the advantage of directly providing jump isolation information, but suffers from computational problems. It might be possible to use the WSSR to detect state jumps and then switch to the BH system for jump isolation and estimate compensation.

  20. Improvement of Subsonic Basic Research Tunnel Flow Quality as Applied to Wall Mounted Testing

    NASA Technical Reports Server (NTRS)

    Howerton, Brian M.

    1995-01-01

    A survey to determine the characteristics of a boundary layer that forms on the wall of the Subsonic Basic Research Tunnel has been performed. Early results showed significant differences in the velocity profiles as measured spanwise across the wall. An investigation of the flow in the upstream contraction revealed the presence of a separation bubble at the beginning of the contraction which caused much of the observed unsteadiness. Vortex generators were successfully applied to the contraction inlet to alleviate the separation. A final survey of the wall boundary layer revealed variations in the displacement and momentum thicknesses to be less than +/- 5% for all but the most upper portion of the wall. The flow quality was deemed adequate to continue the planned follow-on tests to help develop the semi-span test technique.

  1. EUCAST recommendations for antimicrobial susceptibility testing applied to the three main Campylobacter species isolated in humans.

    PubMed

    Sifré, Elodie; Salha, Ben Amor; Ducournau, Astrid; Floch, Pauline; Chardon, Hubert; Mégraud, Francis; Lehours, Philippe

    2015-12-01

    Antimicrobial susceptibility testing of Campylobacter isolates is of great importance for treatment options especially in systemic diseases. The European Committee for Antimicrobial Susceptibility Testing (EUCAST) recently proposed epidemiological cut-offs (ECOFFs) for a limited number of antimicrobial compounds and for Campylobacter jejuni and Campylobacter coli only. In the present study, the EUCAST method was used after minor modifications to define antimicrobial susceptibility patterns for, 1997 C. jejuni, 419 C. coli and 100 Campylobacter fetus strains received at the French National Reference Center for Campylobacters and Helicobacters. Our results show that the ECOFFs defined by EUCAST for tetracycline and ciprofloxacin can be used for C. jejuni and C. coli. The same ECOFF can be used for erythromycin for the three species. The C. jejuni and C. coli ECOFFs for ciprofloxacin however cannot be applied to C. fetus. We also provide data to categorise two 2 β-lactams of interest for systemic diseases, ampicillin and amoxicillin+clavulanate, for the three species.

  2. Germination of Astragalus hamosus L. and Coronilla scorpioides (L.) as influenced by temperature.

    PubMed

    Khélil, A Zoghlami; Hassen, H; Benyoussef, S

    2011-06-15

    Seed germination of two pasture legumes was tested under dark conditions at three alternating temperatures of 5-20, 15-20, 20-35 degrees C and constant 20 degrees C. Duration of the alternating temperatures was 12 h. The seedling counts were checked every day during four weeks. Species differed significantly in germination response to temperature. A. hamosus was more sensitive to temperature than C. scorpioides. The temperature of 20-35 degrees C was more favourable for the germination of A. hamosus than constant 20 degrees C which markedly reduced its germination. The interaction between accessions and temperatures for total germination was significant in both species. In A. hamosus, almost 50% of germination was achieved by all accessions by the first week at alternating 20-35 degrees C temperature while in C. scorpioides, average total germination was significantly low (4%) even by the 28th day. A total rate of 11 and 9% of germination were recorded by two accessions from Ouesslatia (210) and Agareb (19), respectively. A considerable variation for germination was observed among accessions of both species. Temperature requirements for seed germination of the studied species suggest why they are relatively easy or difficult to establish in the field. A. hamosus, with very small seeds required relatively high alternating temperature for germination than C. scorpioides which was insensitive to temperature and has relatively bigger seeds.

  3. Natural variation in germination responses of Arabidopsis to seasonal cues and their associated physiological mechanisms

    PubMed Central

    Barua, Deepak; Butler, Colleen; Tisdale, Tracy E.; Donohue, Kathleen

    2012-01-01

    Background and Aims Despite the intense interest in phenological adaptation to environmental change, the fundamental character of natural variation in germination is almost entirely unknown. Specifically, it is not known whether different genotypes within a species are germination specialists to particular conditions, nor is it known what physiological mechanisms of germination regulation vary in natural populations and how they are associated with responses to particular environmental factors. Methods We used a set of recombinant inbred genotypes of Arabidopsis thaliana, in which linkage disequilibrium has been disrupted over seven generations, to test for genetic variation and covariation in germination responses to distinct environmental factors. We then examined physiological mechanisms associated with those responses, including seed-coat permeability and sensitivity to the phytohormones gibberellic acid (GA) and abscisic acid (ABA). Key Results Genetic variation for germination was environment-dependent, but no evidence for specialization of germination to different conditions was found. Hormonal sensitivities also exhibited significant genetic variation, but seed-coat properties did not. GA sensitivity was associated with germination responses to multiple environmental factors, but seed-coat permeability and ABA sensitivity were associated with specific germination responses, suggesting that an evolutionary change in GA sensitivity could affect germination in multiple environments, but that of ABA sensitivity may affect germination under more restricted conditions. Conclusions The physiological mechanisms of germination responses to specific environmental factors therefore can influence the ability to adapt to diverse seasonal environments encountered during colonization of new habitats or with future predicted climate change. PMID:22012958

  4. Evaluation of feasibility of static tests applied to Küre VMS ore deposits

    NASA Astrophysics Data System (ADS)

    Demirel, Cansu; Çelik Balci, Nurgül; Şeref Sönmez, M.

    2015-04-01

    Küre volcanogenic massive sulfide (VMS) ore deposits have been mined for its copper content for over centuries. However, there is no published data on AMD around Küre VMS ore deposits. This study investigates the sources of acid producing mechanisms in Küre, using field and laboratorial approaches. Geochemical static tests to predict AMD generation are widely applied to mining sites for assessing potential environmental consequences. However, there are well known limitations of these methods particularly resulting from assumptions used for calculations. To test the feasibility of the methods to predict potential of AMD generation of Küre (VMS) copper deposits, for the first time, acid production and neutralization potential of various mine wastes of Küre (VMS) copper deposits were determined. To test our static test results, in situ and laboratory geochemical data were also obtained from the groundwater discharges from Bakibaba underground mining tunnels. Feasibility study showed that, despite a few inconsistencies, static tests were suitable for predicting generation of AMD around Küre copper mining site and reflected well the site conditions. The current study revealed that pulp density, defined as solid/liquid ratio and used for static tests, is an important limiting factor to predict reliable data for AMD generation. In this study, we also determined surface waters affected by AMD are predicted to have a pH value between 3 and 5, with an average of pH 4. Excessive concentrations of manganese, copper, cobalt and sulfate are also noted with considerable amounts of iron and zinc, which can reach to toxic levels. Moreover, iron and zinc were found to be the controlling the fate of metals by precipitation and co-precipitation, due to their relatively depleted concentrations at redox shifting zones. Key words: Küre pyritic copper ore, Bakibaba mining tunnels, volcanogenic massive sulfide ore deposits, acid production potential, neutralization potential

  5. Photoinhibition of germination in grass seed--implications for prairie revegetation.

    PubMed

    Mollard, Federico P O; Naeth, M Anne

    2014-09-01

    Germination photoinhibition is not a recognized cause of revegetation failure; yet prolonged sunlight exposure can inhibit germination of several grass species. This research addressed susceptibility to photoinhibition of selected native grass species used to restore Canadian prairies, and reclamation treatments to alter environmental conditions in order to release seeds from photoinhibition. Under laboratory conditions effects of photoinhibition were tested on the ability of seeds to germinate at low water potential and effects of daily alternating temperatures and nitrates to break photoinhibition. Whether surficial mulch can release seeds from photoinhibition was assessed in a field experiment. Germination photoinhibition was evident in Festuca hallii and Koeleria macrantha seeds even under very low irradiances. The prolonged exposure to light decreased germination rates and ability of seeds to germinate at low water potentials. Daily fluctuating temperatures released a fraction of Bromus carinatus and Elymus trachycaulus seeds from photoinhibition yet did not improve F. hallii or K. macrantha germinability. Nitrates failed to break seed photoinhibition in all species tested. In the field experiment, mulched F. hallii seeds (covered with an erosion control blanket) showed a tenfold increase in germination percentages relative to seeds exposed to direct sunlight, indicating the facilitative effects of mulching on attenuation of the light environment. We conclude that germination photoinhibition as a cause of emergence failures in land reclamation where seed is broadcast or shallow seeded should be recognized and germination photoinhibition included in the decision making process to select revegetation seeding techniques.

  6. Testing and Analysis Validation of a Metallic Repair Applied to a PRSEUS Tension Panel

    NASA Technical Reports Server (NTRS)

    Przekop, Adam; Jegley, Dawn C.

    2013-01-01

    A design and analysis of a repair concept applicable to a stiffened composite panel based on the Pultruded Rod Stitched Efficient Unitized Structure was recently completed. The damage scenario considered was a midbay-to-midbay saw-cut with a severed stiffener, flange and skin. Advanced modeling techniques such as mesh-independent definition of compliant fasteners and elastic-plastic material properties for metal parts were utilized in the finite element analysis supporting the design effort. A bolted metallic repair was selected so that it could be easily applied in the operational environment. The present work describes results obtained from a tension panel test conducted to validate both the repair concept and finite element analysis techniques used in the design effort. The test proved that the proposed repair concept is capable of sustaining load levels that are higher than those resulting from the current working stress allowables. This conclusion enables upward revision of the stress allowables that had been kept at an overly-conservative level due to concerns associated with repairability of the panels. Correlation of test data with finite element analysis results is also presented and assessed.

  7. Testing of evaluation methods applied to raw infiltration data measured at very heterogeneous mountain forest soils

    NASA Astrophysics Data System (ADS)

    Jacka, Lukas; Pavlasek, Jirka; Pech, Pavel

    2016-04-01

    In order to obtain infiltration parameters and analytical expressions of the cumulative infiltration and infiltration rate, raw infiltration data are often evaluated using various infiltration equations. Knowledge about the evaluation variability of these equations in the specific case of extremely heterogeneous soils provides important information for many hydrological and engineering applications. This contribution presents an evaluation of measured data using five well-established physically-based equations and empirical equations, and makes a comparison of these procedures. Evaluation procedures were applied to datasets measured on three different sites of hydrologically important mountain podzols. A total of 47 single ring infiltration experiments were evaluated using these procedures. From the quality-of-fit perspective, all of the tested equations characterized most of the raw datasets properly. In a few cases, some of the physically-based equations led to poor fits of the datasets measured on the most heterogeneous site (characterized by the lowest depth of the organic horizon, and more bleached eluvial horizon than on the other tested sites). For the parameters evaluated on this site, the sorptivity estimates and the saturated hydraulic conductivity (Ks) estimates were distinctly different between the tested procedures.

  8. Design, fabrication, and test of a graphite/epoxy metering truss. [as applied to the LST

    NASA Technical Reports Server (NTRS)

    Oken, S.; Skoumal, D. E.

    1975-01-01

    A graphite/epoxy metering truss as applied to the large space telescope was investigated. A full-scale truss was designed, fabricated and tested. Tests included static limit loadings, a modal survey and thermal-vacuum distortion evaluation. The most critical requirement was the demonstration of the dimensional stability provided by the graphite/epoxy truss concept. Crucial to the attainment of this objective was the ability to make very sophisticated thermal growth measurements which was provided by a seven beam laser interferometer. The design of the basic truss elements were tuned to provide the high degree of dimensional stability and stiffness required by the truss. The struts and spider assembly were fabricated with Fiberite's AS/934 and HMS/934 broadgoods. The rings utilized T300 graphite fabricate with the same materials. The predicted performance of the truss was developed using the NASTRAN program. These results showed conformance with the critical stiffness and thermal distortion requirements and correlated well with the test results.

  9. Does passage time through the lizard Podarcis lilfordi's guts affect germination performance in the plant Withania frutescens?

    NASA Astrophysics Data System (ADS)

    Castilla, Aurora M.

    2000-03-01

    I tested predictions of the hypothesis that a longer seed passage time through the gut of the lizard Podarcis lilfordi enhances germination performance in the plant Withania frutescens. I compared germination success and germination time between seeds that were ingested by lizards and control seeds that were not. I also explored relationships between natural variation in seed passage time and germination performance. Germination success did not differ between ingested (63 %) and non-ingested seeds (56 %); there was no significant relationship between germinability and retention time. Germination time did not differ between ingested and non-ingested seeds, and was unrelated to retention time. Hence, I found no support for the hypothesis that prolonged retention times should improve germination performance. In addition, this is a pilot study stressing the importance of reptiles as seed dispersers, at least in certain habitats.

  10. ISO 10360 verification tests applied to CMMs equipped with a laser line scanner

    NASA Astrophysics Data System (ADS)

    Boeckmans, B.; Probst, G.; Zhang, M.; Dewulf, W.; Kruth, J.-P.

    2016-05-01

    Within the field of quality control and dimensional metrology, the evolutions in the domain of production processes are triggering more use of non-contact measurement equipment to assure faster feature assessment where possible. This led to the development of for instance laser line scanners. The standardization of these new tools follows these novel evolutions. As the coordinate measuring systems (CMSs) which include coordinate measuring machines (CMMs) with its diversity in measurement probes widens its spectrum, the ISO 10360 standard series is rearranged and split up in more parts, covering specific probe groups. The previously mentioned laser line scanners, that can be equipped on a CMM, are integrated within ISO 10360-8 which applies for CMMs equipped with optical distance sensors. This paper is an example of how to interpret and apply this standard to a specific optical distance sensor. This has to be done by taking into account the sensor's characteristics. The intrinsic properties in the technique require an in-depth look at the recommended guidelines within the standard. Furthermore, the guidelines are adapted to use the same capabilities of the laser line scanner, which are used for measuring, without eliminating the uncertainties present in practical use of the sensor. The verification tests and their implementation are discussed, adapted to the sensors needs and performed on a state-of-the-art CMM. The verification parameter results are determined, presented and critically evaluated.

  11. Germination characteristics of six plant species growing on the Hanford Site. [Disturbed land revegetation feasibility studies

    SciTech Connect

    Cox, G.R.; Kirkham, R.R.; Cline, J.F.

    1980-03-01

    Six plant species (Siberian and thickspike wheatgrass, cheatgrass, sand dropseed, Indian ricegrass, and Russian thistle) found on the Hanford Site were studied as part of an investigation into the revegetation of disturbed areas. Germination response to three environmental parameters (soil moisture, soil temperature, and planting depth) were measured. Results indicated that when a polyethylene glycol solution was used to control the osmotic potential of the imbibition media, no significant decrease in germination rate occurred down to -3.0 bars. However, below -7.0 bars all species experienced a decrease in germination. When germinated in soil, all species except Russian thistle exhibited a significant decrease in germination rate at -0.3 bars. Russian thistle was the only species tested that exhibited germination at a soil temperature of 1/sup 0/C. All species gave optimum germination at temperatures between 10 and 15/sup 0/C. Thickspike wheatgrass was the only species tested which was able to germinate and emerge from a planting depth of greater than 2 inches. If supplemental moisture is provided, a shallow planting would be advisable for those species tested. If not overcome by pretreatment prior to planting, seed dormancy may be a significant factor which will reduce the germination potential of some species tested.

  12. Heat pre-treatment and the germination of soil- and canopy-stored seeds of south-western Australian species

    NASA Astrophysics Data System (ADS)

    Hanley, Mick E.; Lamont, Byron B.

    2000-12-01

    The role of heat (shock) in stimulating the germination of soil-stored hard seeds from fire-following species is well known. However, the effects of high temperatures on germination of canopy-stored (serotinous) seeds are less well understood. In this study, we examined the effect of heat shock at four temperatures (60, 80, 100 and 120 °C) applied for 10 min on the germination of ten co-occurring Western Australian fire-following species (five hardseeded, five serotinous). Unlike previous studies, we distinguished between the effects of heat shock on germination rate, as well as total seedling emergence. In comparison with unheated controls, a heat pulse at one or more temperatures increased total germination and germination rate for three of the hardseeded species ( Acacia pulchella, Daviesia cordata and Trymalium ledifolium). The precise pattern of germination response for D. cordata was influenced by whether we examined total germination or germination rate. Germination of four serotinous species ( Calothamnus quadrifidus and three Hakea species) was unaffected by pre-treatments at one or more above-ambient temperatures. Only Allocasuarina humilis displayed both increased rate and total germination at higher temperatures. Our results show that germination in some serotinous species may respond favourably to, or at least be unaffected by, the passage of fire.

  13. Steroid hormone runoff from agricultural test plots applied with municipal biosolids

    USGS Publications Warehouse

    Yang, Yun-Ya; Gray, James L.; Furlong, Edward T.; Davis, Jessica G.; ReVollo, Rhiannon C.; Borch, Thomas

    2012-01-01

    The potential presence of steroid hormones in runoff from sites where biosolids have been used as agricultural fertilizers is an environmental concern. A study was conducted to assess the potential for runoff of seventeen different hormones and two sterols, including androgens, estrogens, and progestogens from agricultural test plots. The field containing the test plots had been applied with biosolids for the first time immediately prior to this study. Target compounds were isolated by solid-phase extraction (water samples) and pressurized solvent extraction (solid samples), derivatized, and analyzed by gas chromatography–tandem mass spectrometry. Runoff samples collected prior to biosolids application had low concentrations of two hormones (estrone -1 and androstenedione -1) and cholesterol (22.5 ± 3.8 μg L-1). In contrast, significantly higher concentrations of multiple estrogens (-1), androgens (-1), and progesterone (-1) were observed in runoff samples taken 1, 8, and 35 days after biosolids application. A significant positive correlation was observed between antecedent rainfall amount and hormone mass loads (runoff). Hormones in runoff were primarily present in the dissolved phase (<0.7-μm GF filter), and, to a lesser extent bound to the suspended-particle phase. Overall, these results indicate that rainfall can mobilize hormones from biosolids-amended agricultural fields, directly to surface waters or redistributed to terrestrial sites away from the point of application via runoff. Although concentrations decrease over time, 35 days is insufficient for complete degradation of hormones in soil at this site.

  14. Phase-locked-loop interferometry applied to aspheric testing with a computer-stored compensator.

    PubMed

    Servin, M; Malacara, D; Rodriguez-Vera, R

    1994-05-01

    A recently developed technique for continuous-phase determination of interferograms with a digital phase-locked loop (PLL) is applied to the null testing of aspheres. Although this PLL demodulating scheme is also a synchronous or direct interferometric technique, the separate unwrapping process is not explicitly required. The unwrapping and the phase-detection processes are achieved simultaneously within the PLL. The proposed method uses a computer-generated holographic compensator. The holographic compensator does not need to be printed out by any means; it is calculated and used from the computer. This computer-stored compensator is used as the reference signal to phase demodulate a sample interferogram obtained from the asphere being tested. Consequently the demodulated phase contains information about the wave-front departures from the ideal computer-stored aspheric interferogram. Wave-front differences of ~ 1 λ are handled easily by the proposed PLL scheme. The maximum recorded frequency in the template's interferogram as well as in the sampled interferogram are assumed to be below the Nyquist frequency.

  15. A Monte Carlo approach applied to ultrasonic non-destructive testing

    NASA Astrophysics Data System (ADS)

    Mosca, I.; Bilgili, F.; Meier, T.; Sigloch, K.

    2012-04-01

    Non-destructive testing based on ultrasound allows us to detect, characterize and size discrete flaws in geotechnical and architectural structures and materials. This information is needed to determine whether such flaws can be tolerated in future service. In typical ultrasonic experiments, only the first-arriving P-wave is interpreted, and the remainder of the recorded waveform is neglected. Our work aims at understanding surface waves, which are strong signals in the later wave train, with the ultimate goal of full waveform tomography. At present, even the structural estimation of layered media is still challenging because material properties of the samples can vary widely, and good initial models for inversion do not often exist. The aim of the present study is to combine non-destructive testing with a theoretical data analysis and hence to contribute to conservation strategies of archaeological and architectural structures. We analyze ultrasonic waveforms measured at the surface of a variety of samples, and define the behaviour of surface waves in structures of increasing complexity. The tremendous potential of ultrasonic surface waves becomes an advantage only if numerical forward modelling tools are available to describe the waveforms accurately. We compute synthetic full seismograms as well as group and phase velocities for the data. We invert them for the elastic properties of the sample via a global search of the parameter space, using the Neighbourhood Algorithm. Such a Monte Carlo approach allows us to perform a complete uncertainty and resolution analysis, but the computational cost is high and increases quickly with the number of model parameters. Therefore it is practical only for defining the seismic properties of media with a limited number of degrees of freedom, such as layered structures. We have applied this approach to both synthetic layered structures and real samples. The former contributed to benchmark the propagation of ultrasonic surface

  16. Protein mobilization in germinating mung bean seeds involves vacuolar sorting receptors and multivesicular bodies.

    PubMed

    Wang, Junqi; Li, Yubing; Lo, Sze Wan; Hillmer, Stefan; Sun, Samuel S M; Robinson, David G; Jiang, Liwen

    2007-04-01

    Plants accumulate and store proteins in protein storage vacuoles (PSVs) during seed development and maturation. Upon seed germination, these storage proteins are mobilized to provide nutrients for seedling growth. However, little is known about the molecular mechanisms of protein degradation during seed germination. Here we test the hypothesis that vacuolar sorting receptor (VSR) proteins play a role in mediating protein degradation in germinating seeds. We demonstrate that both VSR proteins and hydrolytic enzymes are synthesized de novo during mung bean (Vigna radiata) seed germination. Immunogold electron microscopy with VSR antibodies demonstrate that VSRs mainly locate to the peripheral membrane of multivesicular bodies (MVBs), presumably as recycling receptors in day 1 germinating seeds, but become internalized to the MVB lumen, presumably for degradation at day 3 germination. Chemical cross-linking and immunoprecipitation with VSR antibodies have identified the cysteine protease aleurain as a specific VSR-interacting protein in germinating seeds. Further confocal immunofluorescence and immunogold electron microscopy studies demonstrate that VSR and aleurain colocalize to MVBs as well as PSVs in germinating seeds. Thus, MVBs in germinating seeds exercise dual functions: as a storage compartment for proteases that are physically separated from PSVs in the mature seed and as an intermediate compartment for VSR-mediated delivery of proteases from the Golgi apparatus to the PSV for protein degradation during seed germination.

  17. Factors influencing seed germination of medicinal plant Salvia aegyptiaca L. (Lamiaceae)

    PubMed Central

    Gorai, Mustapha; Gasmi, Hayet; Neffati, Mohamed

    2011-01-01

    Salvia aegyptiaca is a xerophytic perennial herb belongs to the Lamiaceae family commonly used for medicinal purposes. Laboratory experiments were carried out to assess the effects of temperature and salinity on seed germination and recovery responses after transferring to distilled water. Temperatures between 10 and 40 °C seem to be favourable for the germination of this species. Germination was inhibited by either an increase or decrease in temperature from the optimum (30 °C). The highest germination percentages were obtained at 0 mM NaCl; however, the increase of solution osmolalities progressively inhibited seed germination. The germination rate decreased with an increase in salinity for most of tested temperatures, but comparatively higher rates were obtained at 30 °C. Salt stress decreased both the percentage and the rate of germination. An interaction between salinity and temperature yielded no germination at 300 mM NaCl. By experimental transfer to distilled water, S. aegyptiaca seeds that were exposed to moderately saline conditions recovered and keep their ability to germinate mostly at low temperatures. At 300 mM NaCl, germination recovery decreased with increasing temperature and it was completely inhibited at 40 °C. PMID:23961132

  18. Microbe associated molecular patterns from rhizosphere bacteria trigger germination and Papaver somniferum metabolism under greenhouse conditions.

    PubMed

    Bonilla, A; Sarria, A L F; Algar, E; Muñoz Ledesma, F J; Ramos Solano, B; Fernandes, J B; Gutierrez Mañero, F J

    2014-01-01

    Ten PGPR from different backgrounds were assayed on Papaver somniferum var. Madrigal to evaluate their potential as biotic elicitors to increase alkaloid content under the rationale that some microbe associated molecular patterns (MAMPs) are able to trigger plant metabolism. First, the 10 strains and their culture media at two different concentrations were tested for their ability to trigger seed germination. Then, the best three strains were tested for their ability to increase seedling growth and alkaloid levels under greenhouse conditions. Only three strains and their culture media enhanced germination. Then, germination enhancing capacity of these best three strains, N5.18 Stenotrophomonas maltophilia, Aur9 Chryseobacterium balustinum and N21.4 Pseudomonas fluorescens was evaluated in soil. Finally, the three strains were applied on seedlings at two time points, by soil drench or by foliar spray. Photosynthesis was measured, plant height was recorded, capsules were weighted and alkaloids analyzed by HPLC. Only N5.18 delivered by foliar spray significantly increased plant height coupled to an increase in total alkaloids and a significant increase in opium poppy straw dry weight; these increases were supported by a better photosynthetic efficiency. The relative contents of morphine, thebaine, codeine and oripavine were affected by this treatment causing a significant increase in morphine coupled to a decrease in thebaine, demonstrating the effectivity of MAMPs from N5.18 in this plant species. Considering the increase in capsule biomass and alkaloids together with the acceleration of germination, strain N5.18 appears as a good candidate to elicit plant metabolism and consequently, to increase productivity of Papaver somniferum.

  19. Germinal Centers without T Cells

    PubMed Central

    de Vinuesa, Carola García; Cook, Matthew C.; Ball, Jennifer; Drew, Marion; Sunners, Yvonne; Cascalho, Marilia; Wabl, Matthias; Klaus, Gerry G.B.; MacLennan, Ian C.M.

    2000-01-01

    Germinal centers are critical for affinity maturation of antibody (Ab) responses. This process allows the production of high-efficiency neutralizing Ab that protects against virus infection and bacterial exotoxins. In germinal centers, responding B cells selectively mutate the genes that encode their receptors for antigen. This process can change Ab affinity and specificity. The mutated cells that produce high-affinity Ab are selected to become Ab-forming or memory B cells, whereas cells that have lost affinity or acquired autoreactivity are eliminated. Normally, T cells are critical for germinal center formation and subsequent B cell selection. Both processes involve engagement of CD40 on B cells by T cells. This report describes how high-affinity B cells can be induced to form large germinal centers in response to (4-hydroxy-3-nitrophenyl) acetyl (NP)-Ficoll in the absence of T cells or signaling through CD40 or CD28. This requires extensive cross-linking of the B cell receptors, and a frequency of antigen-specific B cells of at least 1 in 1,000. These germinal centers abort dramatically at the time when mutated high-affinity B cells are normally selected by T cells. Thus, there is a fail-safe mechanism against autoreactivity, even in the event of thymus-independent germinal center formation. PMID:10662794

  20. In vitro pollen viability and pollen germination in cherry laurel (Prunus laurocerasus L.).

    PubMed

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r(2) = 0.0614 and r(2) = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  1. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.)

    PubMed Central

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media. PMID:25405230

  2. Steroid hormone runoff from agricultural test plots applied with municipal biosolids.

    PubMed

    Yang, Yun-Ya; Gray, James L; Furlong, Edward T; Davis, Jessica G; Revello, Rhiannon C; Borch, Thomas

    2012-03-01

    The potential presence of steroid hormones in runoff from sites where biosolids have been used as agricultural fertilizers is an environmental concern. A study was conducted to assess the potential for runoff of seventeen different hormones and two sterols, including androgens, estrogens, and progestogens from agricultural test plots. The field containing the test plots had been applied with biosolids for the first time immediately prior to this study. Target compounds were isolated by solid-phase extraction (water samples) and pressurized solvent extraction (solid samples), derivatized, and analyzed by gas chromatography-tandem mass spectrometry. Runoff samples collected prior to biosolids application had low concentrations of two hormones (estrone <0.8 to 2.23 ng L(-1) and androstenedione <0.8 to 1.54 ng L(-1)) and cholesterol (22.5 ± 3.8 μg L(-1)). In contrast, significantly higher concentrations of multiple estrogens (<0.8 to 25.0 ng L(-1)), androgens (<2 to 216 ng L(-1)), and progesterone (<8 to 98.9 ng L(-1)) were observed in runoff samples taken 1, 8, and 35 days after biosolids application. A significant positive correlation was observed between antecedent rainfall amount and hormone mass loads (runoff). Hormones in runoff were primarily present in the dissolved phase (<0.7-μm GF filter), and, to a lesser extent bound to the suspended-particle phase. Overall, these results indicate that rainfall can mobilize hormones from biosolids-amended agricultural fields, directly to surface waters or redistributed to terrestrial sites away from the point of application via runoff. Although concentrations decrease over time, 35 days is insufficient for complete degradation of hormones in soil at this site.

  3. Phosphorus recycling potential assessment by a biological test applied to wastewater sludge.

    PubMed

    Braak, Etienne; Auby, Sarah; Piveteau, Simon; Guilayn, Felipe; Daumer, Marie-Line

    2016-01-01

    Phosphorus (P) recycling as mineral fertilizer from wastewater activated sludge (WAS) depends on the amount that can be dissolved and separated from the organic matter before the final crystallization step. The aim of the biological phosphorus dissolution potential (BPDP) test developed here was to assess the maximum amount of P that could be biologically released from WAS prior that the liquid phase enters the recovery process. It was first developed for sludge combining enhanced biological phosphorus removal and iron chloride. Because carbohydrates are known to induce acidification during the first stage of anaerobic digestion, sucrose was used as a co-substrate. Best results were obtained after 24-48 h, without inoculum, with a sugar/sludge ratio of 0.5 gCOD/gVS and under strict anaerobic conditions. Up to 75% of the total phosphorus in sludge from a wastewater treatment plant combining enhanced biological phosphorus removal and iron chloride phosphorus removal could be dissolved. Finally, the test was applied to assess BPDP from different sludge using alum compounds for P removal. No dissolution was observed when alum polychloride was used and less than 20% when alum sulphate was used. In all the cases, comparison to chemical acidification showed that the biological process was a major contributor to P dissolution. The possibility to crystallize struvite was discussed from the composition of the liquids obtained. The BPDP will be used not only to assess the potential for phosphorus recycling from sludge, but also to study the influence of the co-substrates available for anaerobic digestion of sludge.

  4. A Monte Carlo approach applied to ultrasonic non-destructive testing

    NASA Astrophysics Data System (ADS)

    Mosca, I.; Bilgili, F.; Meier, T. M.; Sigloch, K.

    2011-12-01

    Non-destructive testing based on ultrasound allows us to detect, characterize and size discrete flaws in geotechnical and engineering structures and materials. This information is needed to determine whether such flaws can be tolerated in future service. In typical ultrasonic experiments, only the first-arriving P-wave is interpreted, and the remainder of the recorded waveform is neglected. Our work aims at understanding surface waves, which are strong signals in the later wave train, with the ultimate goal of full waveform tomography. At present, even the structural estimation of layered media is still challenging because material properties of the samples can vary widely, and good initial models for inversion do not often exist. The aim of the present study is to analyze ultrasonic waveforms measured at the surface of Plexiglas and rock samples, and to define the behaviour of surface waves in structures of increasing complexity. The tremendous potential of ultrasonic surface waves becomes an advantage only if numerical forward modelling tools are available to describe the waveforms accurately. We compute synthetic full seismograms as well as group and phase velocities for the data. We invert them for the elastic properties of the sample via a global search of the parameter space, using the Neighbourhood Algorithm. Such a Monte Carlo approach allows us to perform a complete uncertainty and resolution analysis, but the computational cost is high and increases quickly with the number of model parameters. Therefore it is practical only for defining the seismic properties of media with a limited number of degrees of freedom, such as layered structures. We have applied this approach to both synthetic layered structures and real samples. The former contributed to benchmark the propagation of ultrasonic surface waves in typical materials tested with a non-destructive technique (e.g., marble, unweathered and weathered concrete and natural stone).

  5. Phosphorus recycling potential assessment by a biological test applied to wastewater sludge.

    PubMed

    Braak, Etienne; Auby, Sarah; Piveteau, Simon; Guilayn, Felipe; Daumer, Marie-Line

    2016-01-01

    Phosphorus (P) recycling as mineral fertilizer from wastewater activated sludge (WAS) depends on the amount that can be dissolved and separated from the organic matter before the final crystallization step. The aim of the biological phosphorus dissolution potential (BPDP) test developed here was to assess the maximum amount of P that could be biologically released from WAS prior that the liquid phase enters the recovery process. It was first developed for sludge combining enhanced biological phosphorus removal and iron chloride. Because carbohydrates are known to induce acidification during the first stage of anaerobic digestion, sucrose was used as a co-substrate. Best results were obtained after 24-48 h, without inoculum, with a sugar/sludge ratio of 0.5 gCOD/gVS and under strict anaerobic conditions. Up to 75% of the total phosphorus in sludge from a wastewater treatment plant combining enhanced biological phosphorus removal and iron chloride phosphorus removal could be dissolved. Finally, the test was applied to assess BPDP from different sludge using alum compounds for P removal. No dissolution was observed when alum polychloride was used and less than 20% when alum sulphate was used. In all the cases, comparison to chemical acidification showed that the biological process was a major contributor to P dissolution. The possibility to crystallize struvite was discussed from the composition of the liquids obtained. The BPDP will be used not only to assess the potential for phosphorus recycling from sludge, but also to study the influence of the co-substrates available for anaerobic digestion of sludge. PMID:26786893

  6. Tomato Seed Coat Permeability to Selected Carbon Nanomaterials and Enhancement of Germination and Seedling Growth.

    PubMed

    Ratnikova, Tatsiana A; Podila, Ramakrishna; Rao, Apparao M; Taylor, Alan G

    2015-01-01

    Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20 (fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth.

  7. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  8. Tomato Seed Coat Permeability to Selected Carbon Nanomaterials and Enhancement of Germination and Seedling Growth

    PubMed Central

    Ratnikova, Tatsiana A.; Podila, Ramakrishna; Rao, Apparao M.; Taylor, Alan G.

    2015-01-01

    Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20 (fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth. PMID:26495423

  9. Numerical tests for effects of various parameters in niching genetic algorithm applied to regional waveform inversion

    NASA Astrophysics Data System (ADS)

    Li, Cong; Lei, Jianshe

    2014-10-01

    In this paper, we focus on the influences of various parameters in the niching genetic algorithm inversion procedure on the results, such as various objective functions, the number of the models in each subpopulation, and the critical separation radius. The frequency-waveform integration (F-K) method is applied to synthesize three-component waveform data with noise in various epicentral distances and azimuths. Our results show that if we use a zero-th-lag cross-correlation function, then we will obtain the model with a faster convergence and a higher precision than other objective functions. The number of models in each subpopulation has a great influence on the rate of convergence and computation time, suggesting that it should be obtained through tests in practical problems. The critical separation radius should be determined carefully because it directly affects the multi-extreme values in the inversion. We also compare the inverted results from full-band waveform data and surface-wave frequency-band (0.02-0.1 Hz) data, and find that the latter is relatively poorer but still has a higher precision, suggesting that surface-wave frequency-band data can also be used to invert for the crustal structure.

  10. Numerical tests for effects of various parameters in niching genetic algorithm applied to regional waveform inversion

    NASA Astrophysics Data System (ADS)

    Li, Cong; Lei, Jianshe

    2014-09-01

    In this paper, we focus on the influences of various parameters in the niching genetic algorithm inversion procedure on the results, such as various objective functions, the number of the models in each subpopulation, and the critical separation radius. The frequency-waveform integration (F-K) method is applied to synthesize three-component waveform data with noise in various epicentral distances and azimuths. Our results show that if we use a zero-th-lag cross-correlation function, then we will obtain the model with a faster convergence and a higher precision than other objective functions. The number of models in each subpopulation has a great influence on the rate of convergence and computation time, suggesting that it should be obtained through tests in practical problems. The critical separation radius should be determined carefully because it directly affects the multi-extreme values in the inversion. We also compare the inverted results from full-band waveform data and surface-wave frequency-band (0.02-0.1 Hz) data, and find that the latter is relatively poorer but still has a higher precision, suggesting that surface-wave frequency-band data can also be used to invert for the crustal structure.

  11. Competency Test Items for Applied Principles of Agribusiness and Natural Resources Occupations. Agricultural Production Component. A Report of Research.

    ERIC Educational Resources Information Center

    Cheek, Jimmy G.; McGhee, Max B.

    An activity was undertaken to develop written criterion-referenced tests for the agricultural production component of Applied Principles of Agribusiness and Natural Resources Occupations. Intended for tenth grade students who have completed Fundamentals of Agribusiness and Natural Resources Occupations, applied principles were designed to consist…

  12. 40 CFR 80.583 - What alternative sampling and testing requirements apply to importers who transport motor vehicle...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements apply to importers who transport motor vehicle diesel fuel, NRLM diesel fuel, or ECA marine fuel... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Motor Vehicle Diesel Fuel... alternative sampling and testing requirements apply to importers who transport motor vehicle diesel fuel,...

  13. 40 CFR 1051.505 - What special provisions apply for testing snowmobiles?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for all testing you perform for that engine family. If we test your engines to confirm that they meet emission standards, we will do testing the same way. If you submit certification test data collected with... the established criteria as specified in 40 CFR 1065.514 to confirm that the test is valid. (2)...

  14. 40 CFR 1051.505 - What special provisions apply for testing snowmobiles?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for all testing you perform for that engine family. If we test your engines to confirm that they meet emission standards, we will do testing the same way. If you submit certification test data collected with... the established criteria as specified in 40 CFR 1065.514 to confirm that the test is valid. (2)...

  15. 40 CFR 1051.505 - What special provisions apply for testing snowmobiles?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for all testing you perform for that engine family. If we test your engines to confirm that they meet emission standards, we will do testing the same way. If you submit certification test data collected with... the established criteria as specified in 40 CFR 1065.514 to confirm that the test is valid. (2)...

  16. 40 CFR 1051.505 - What special provisions apply for testing snowmobiles?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for all testing you perform for that engine family. If we test your engines to confirm that they meet emission standards, we will do testing the same way. If you submit certification test data collected with... the established criteria as specified in 40 CFR 1065.514 to confirm that the test is valid. (2)...

  17. 40 CFR 1051.505 - What special provisions apply for testing snowmobiles?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for all testing you perform for that engine family. If we test your engines to confirm that they meet emission standards, we will do testing the same way. If you submit certification test data collected with... the established criteria as specified in 40 CFR 1065.514 to confirm that the test is valid. (2)...

  18. Does proximity to neighbours affect germination of spores of non-proteolytic Clostridium botulinum?

    PubMed

    Webb, Martin D; Stringer, Sandra C; Le Marc, Yvan; Baranyi, József; Peck, Michael W

    2012-10-01

    It is recognised that inoculum size affects the rate and extent of bacterial spore germination. It has been proposed that this is due to spores interacting: molecules released from germinated spores trigger germination of dormant neighbours. This study investigated whether changes to the total number of spores in a system or proximity to other spores (local spore density) had a more significant effect on interaction between spores of non-proteolytic Clostridium botulinum strain Eklund 17B attached to defined areas of microscope slides. Both the number of spores attached to the slides and local spore density (number of spores per mm(2)) were varied by a factor of nine. Germination was observed microscopically at 15 °C for 8 h and the probability of, and time to, germination calculated from image analysis measurements. Statistical analysis revealed that the effect of total spore number on the probability of germination within 8 h was more significant than that of proximity to neighbours (local spore density); its influence on germination probability was approximately four-times greater. Total spore number had an even more significant affect on time to germination; it had a nine-fold greater influence than proximity to neighbours. The applied models provide a means to characterise, quantitatively, the effect of the total spore number on spore germination relative to the effect of proximity to neighbouring spores.

  19. Characterization of the Dynamic Germination of Individual Clostridium difficile Spores Using Raman Spectroscopy and Differential Interference Contrast Microscopy

    PubMed Central

    Wang, Shiwei; Shen, Aimee; Setlow, Peter

    2015-01-01

    ABSTRACT The Gram-positive spore-forming anaerobe Clostridium difficile is a leading cause of nosocomial diarrhea. Spores of C. difficile initiate infection when triggered to germinate by bile salts in the gastrointestinal tract. We analyzed germination kinetics of individual C. difficile spores using Raman spectroscopy and differential interference contrast (DIC) microscopy. Similar to Bacillus spores, individual C. difficile spores germinating with taurocholate plus glycine began slow leakage of a ∼15% concentration of a chelate of Ca2+ and dipicolinic acid (CaDPA) at a heterogeneous time T1, rapidly released CaDPA at Tlag, completed CaDPA release at Trelease, and finished peptidoglycan cortex hydrolysis at Tlysis. T1 and Tlag values for individual spores were heterogeneous, but ΔTrelease periods (Trelease − Tlag) were relatively constant. In contrast to Bacillus spores, heat treatment did not stimulate spore germination in the two C. difficile strains tested. C. difficile spores did not germinate with taurocholate or glycine alone, and different bile salts differentially promoted spore germination, with taurocholate and taurodeoxycholate being best. Transient exposure of spores to taurocholate plus glycine was sufficient to commit individual spores to germinate. C. difficile spores did not germinate with CaDPA, in contrast to B. subtilis and C. perfringens spores. However, the detergent dodecylamine induced C. difficile spore germination, and rates were increased by spore coat removal although cortex hydrolysis did not follow Trelease, in contrast with B. subtilis. C. difficile spores lacking the cortex-lytic enzyme, SleC, germinated extremely poorly, and cortex hydrolysis was not observed in the few sleC spores that partially germinated. Overall, these findings indicate that C. difficile and B. subtilis spore germination exhibit key differences. IMPORTANCE Spores of the Gram-positive anaerobe Clostridium difficile are responsible for initiating infection

  20. 40 CFR 86.1901 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... VEHICLES AND ENGINES Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86.1901 What testing requirements apply to my engines that have gone into service? (a) If you manufacture diesel heavy... engines that have gone into service? 86.1901 Section 86.1901 Protection of Environment...

  1. 10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Random drug and alcohol testing of individuals who have applied for authorization. 26.67 Section 26.67 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.67 Random drug and alcohol testing of individuals...

  2. 29 CFR 794.108 - Scope of enterprise must be known before exemption tests can be applied.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Scope of enterprise must be known before exemption tests...)(3) of the Act The âenterpriseâ § 794.108 Scope of enterprise must be known before exemption tests can be applied. The scope of the “enterprise” as defined by section 3(r) of the Act must...

  3. 29 CFR 794.108 - Scope of enterprise must be known before exemption tests can be applied.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Scope of enterprise must be known before exemption tests...)(3) of the Act The âenterpriseâ § 794.108 Scope of enterprise must be known before exemption tests can be applied. The scope of the “enterprise” as defined by section 3(r) of the Act must...

  4. 29 CFR 794.108 - Scope of enterprise must be known before exemption tests can be applied.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Scope of enterprise must be known before exemption tests...)(3) of the Act The âenterpriseâ § 794.108 Scope of enterprise must be known before exemption tests can be applied. The scope of the “enterprise” as defined by section 3(r) of the Act must...

  5. 29 CFR 794.108 - Scope of enterprise must be known before exemption tests can be applied.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Scope of enterprise must be known before exemption tests...)(3) of the Act The âenterpriseâ § 794.108 Scope of enterprise must be known before exemption tests can be applied. The scope of the “enterprise” as defined by section 3(r) of the Act must...

  6. 29 CFR 794.108 - Scope of enterprise must be known before exemption tests can be applied.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Scope of enterprise must be known before exemption tests...)(3) of the Act The âenterpriseâ § 794.108 Scope of enterprise must be known before exemption tests can be applied. The scope of the “enterprise” as defined by section 3(r) of the Act must...

  7. 10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Random drug and alcohol testing of individuals who have applied for authorization. 26.67 Section 26.67 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.67 Random drug and alcohol testing of individuals...

  8. 10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Random drug and alcohol testing of individuals who have applied for authorization. 26.67 Section 26.67 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.67 Random drug and alcohol testing of individuals...

  9. 10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Random drug and alcohol testing of individuals who have applied for authorization. 26.67 Section 26.67 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.67 Random drug and alcohol testing of individuals...

  10. 10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Random drug and alcohol testing of individuals who have applied for authorization. 26.67 Section 26.67 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.67 Random drug and alcohol testing of individuals...

  11. Applicability of Aerospace Materials Ground Flammability Test Data to Spacecraft Environments Theory and Applied Technologies

    NASA Technical Reports Server (NTRS)

    Hirsch, David; Williams, Jim; Beeson, Harold

    2009-01-01

    This slide presentation reviews the use of ground test data in reference to flammability to spacecraft environments. It reviews the current approach to spacecraft fire safety, the challenges to fire safety that the Constellation program poses, the current trends in the evaluation of the Constellation materials flammability, and the correlation of test data from ground flammability tests with the spacecraft environment. Included is a proposal for testing and the design of experiments to test the flammability of materials under similar spacecraft conditions.

  12. Analysis of Full-Test tools and their limitations as applied to terminal junction blocks

    NASA Technical Reports Server (NTRS)

    Smith, J. L.

    1983-01-01

    Discovery of unlocked contacts in Deutsch Block terminal junctions in Solid Rocket Booster flight hardware prompted an investigation into pull test techniques to help insure against possible failures. Internal frictional forces between socket and pin and between wire and grommet were examined. Pull test force must be greater than internal friction yet less than the crimp strength of the pin or socket. For this reason, a 100 percent accurate test is impossible. Test tools were evaluated. Available tools are adequate for pull testing.

  13. Leveraging a high resolution microfluidic assay reveals insights into pathogenic fungal spore germination.

    PubMed

    Barkal, Layla J; Walsh, Naomi M; Botts, Michael R; Beebe, David J; Hull, Christina M

    2016-05-16

    Germination of spores into actively growing cells is a process essential for survival and pathogenesis of many microbes. Molecular mechanisms governing germination, however, are poorly understood in part because few tools exist for evaluating and interrogating the process. Here, we introduce an assay that leverages developments in microfluidic technology and image processing to quantitatively measure germination with unprecedented resolution, assessing both individual cells and the population as a whole. Using spores from Cryptococcus neoformans, a leading cause of fatal fungal disease in humans, we developed a platform to evaluate spores as they undergo morphological changes during differentiation into vegetatively growing yeast. The assay uses pipet-accessible microdevices that can be arrayed for efficient testing of diverse microenvironmental variables, including temperature and nutrients. We discovered that temperature influences germination rate, a carbon source alone is sufficient to induce germination, and the addition of a nitrogen source sustains it. Using this information, we optimized the assay for use with fungal growth inhibitors to pinpoint stages of germination inhibition. Unexpectedly, the clinical antifungal drugs amphotericin B and fluconazole did not significantly alter the process or timing of the transition from spore to yeast, indicating that vegetative growth and germination are distinct processes in C. neoformans. Finally, we used the high temporal resolution of the assay to determine the precise defect in a slow-germination mutant. Combining advances in microfluidics with a robust fungal molecular genetic system allowed us to identify and alter key temporal, morphological, and molecular events that occur during fungal germination. PMID:27026574

  14. Effects of ethylene and carbon dioxide on the germination of osmotically inhibited lettuce seed.

    PubMed

    Negm, F B; Smith, O E

    1978-10-01

    Lettuce seeds (Lactuca sativa L.) used in this study germinated 98% at 25 C in light or dark. Their germination was completely inhibited by 0.20 m NaCl, 0.35 m mannitol, or polyethylene glycol 6000 (-7 bars) under continuous light when germination tests were made in Petri dishes. Approximately 50% germination occurred in sealed flasks due to endogenously produced C(2)H(4) and CO(2). Removal of either or both gases prevented germination. In the presence of endogenous CO(2), addition of C(2)H(4) (0.5 to 16 microliters/liter) stimulated 95 to 100% germination (after 5 days) only in the light, but the rate of germination was dependent on C(2)H(4) concentration. At 16 microliters/liter C(2)H(4), full germination occurred within 72 hours. Addition of up to 3.2% CO(2) had no adverse effect on the C(2)H(4) action. Higher concentrations or the complete absence of CO(2) reduced both rate and total germination. CO(2) alone was ineffective.Under these osmotic conditions the promotive effect of C(2)H(4) was under the control of phytochrome.

  15. Effects of ethylene and carbon dioxide on the germination of osmotically inhibited lettuce seed.

    PubMed

    Negm, F B; Smith, O E

    1978-10-01

    Lettuce seeds (Lactuca sativa L.) used in this study germinated 98% at 25 C in light or dark. Their germination was completely inhibited by 0.20 m NaCl, 0.35 m mannitol, or polyethylene glycol 6000 (-7 bars) under continuous light when germination tests were made in Petri dishes. Approximately 50% germination occurred in sealed flasks due to endogenously produced C(2)H(4) and CO(2). Removal of either or both gases prevented germination. In the presence of endogenous CO(2), addition of C(2)H(4) (0.5 to 16 microliters/liter) stimulated 95 to 100% germination (after 5 days) only in the light, but the rate of germination was dependent on C(2)H(4) concentration. At 16 microliters/liter C(2)H(4), full germination occurred within 72 hours. Addition of up to 3.2% CO(2) had no adverse effect on the C(2)H(4) action. Higher concentrations or the complete absence of CO(2) reduced both rate and total germination. CO(2) alone was ineffective.Under these osmotic conditions the promotive effect of C(2)H(4) was under the control of phytochrome. PMID:16660541

  16. Carbon nanofibers suppress fungal inhibition of seed germination of maize (Zea mays) and barley (Hordeum vulgare L.) crop

    NASA Astrophysics Data System (ADS)

    Joshi, Anjali; Sharma, Arti; Nayyar, Harsh; Verma, Gaurav; Dharamvir, Keya

    2015-08-01

    Carbon nanofibers (CNFs) are one of allotropes of carbon, consists of graphene layers arrangement in the form of stacked cones or like a cup diameter in nanometer and several millimeters in length. Their extraordinary mechanical, chemical and electronic properties are due to their small size. CNFs have been successfully applied in field of medicine in variety of diagnostic methods. They proven to be an excellent system for drug delivery, tissue regeneration, biosensor etc. This research focuses the applications of CNFs in all fields of Agriculture. In the we treated some fungal disease seed of maize and barley using functionalised CNFs. We find that the tested seeds grow just as well as the healthy seeds whereas the untreated fungal disease seeds, by themselves show very poor germination and seedling growth. This simple experiment shows the extraordinary ability of Carbon nanofibers in carrying effectively inside the germinated seeds.

  17. Carbon nanofibers suppress fungal inhibition of seed germination of maize (Zea mays) and barley (Hordeum vulgare L.) crop

    SciTech Connect

    Joshi, Anjali Sharma, Arti; Nayyar, Harsh; Verma, Gaurav; Dharamvir, Keya

    2015-08-28

    Carbon nanofibers (CNFs) are one of allotropes of carbon, consists of graphene layers arrangement in the form of stacked cones or like a cup diameter in nanometer and several millimeters in length. Their extraordinary mechanical, chemical and electronic properties are due to their small size. CNFs have been successfully applied in field of medicine in variety of diagnostic methods. They proven to be an excellent system for drug delivery, tissue regeneration, biosensor etc. This research focuses the applications of CNFs in all fields of Agriculture. In the we treated some fungal disease seed of maize and barley using functionalised CNFs. We find that the tested seeds grow just as well as the healthy seeds whereas the untreated fungal disease seeds, by themselves show very poor germination and seedling growth. This simple experiment shows the extraordinary ability of Carbon nanofibers in carrying effectively inside the germinated seeds.

  18. Shear-Sensitive Liquid Crystal Coating Method Applied Through Transparent Test Surfaces

    NASA Technical Reports Server (NTRS)

    Reda, Daniel C.; Wilder, Michael C.

    1999-01-01

    Research conducted at NASA Ames Research Center has shown that the color-change response of a shear-sensitive liquid crystal coating (SSLCC) to aerodynamic shear depends on both the magnitude of the local shear vector and its direction relative to the observer's in-plane line of sight. In conventional applications, the surface of the SSLCC exposed to aerodynamic shear is illuminated with white light from the normal direction and observed from an oblique above-plane view angle of order 30 deg. In this top-light/top-view mode, shear vectors with components directed away from the observer cause the SSLCC to exhibit color-change responses. At any surface point, the maximum color change (measured from the no-shear red or orange color) always occurs when the local vector is aligned with, and directed away from, the observer. The magnitude of the color change at this vector-observer-aligned orientation scales directly with shear stress magnitude. Conversely, any surface point exposed to a shear vector with a component directed toward the observer exhibits a non-color-change response, always characterized by a rusty-red or brown color, independent of both shear magnitude and direction. These unique, highly directional color-change responses of SSLCCs to aerodynamic shear allow for the full-surface visualization and measurement of continuous shear stress vector distributions. The objective of the present research was to investigate application of the SSLCC method through a transparent test surface. In this new back-light/back-view mode, the exposed surface of the SSLCC would be subjected to aerodynamic shear stress while the contact surface between the SSLCC and the solid, transparent wall would be illuminated and viewed in the same geometrical arrangement as applied in conventional applications. It was unknown at the outset whether or not color-change responses would be observable from the contact surface of the SSLCC, and, if seen, how these color-change responses might

  19. Ethylene, seed germination, and epinasty.

    PubMed

    Stewart, E R; Freebairn, H T

    1969-07-01

    Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis. This procedure enabled a separation of the production of ethylene from the effect of ethylene. Ethylene was required in tomato petioles to produce the epinastic response and auxin was found to be active in producing epinasty through a stimulation of ethylene synthesis with the resulting ethylene being responsible for the epinasty. In the same manner, it was shown that gibberellic acid stimulated ethylene synthesis in lettuce seeds. The ethylene produced then in turn stimulated the seeds to germinate. It was hypothesized that ethylene was the intermediate which caused epinasty or seed germination. Auxin and gibberellin primarily induced their response by stimulating ethylene production.

  20. Prototype of a test bench for applied research on Extracted beams of the nuclotron accelerator complex

    NASA Astrophysics Data System (ADS)

    Baldin, A. A.; Berlev, A. I.; Bradnova, V.; Butenko, A. V.; Fedorov, A. N.; Kudashkin, I. V.

    2016-05-01

    The results of the development and testing of elements of a test bench for investigating the impact of accelerated particle beams on biological objects, electronics, and other targets are presented. The systems for beam monitoring and target positioning were tested on extracted argon beams in the framework of experiments on studying the radiation hardness of electronic components.

  1. A Comparison of Traditional and Non-Traditional Methods of Testing: Applied Educational Research and Evaluation.

    ERIC Educational Resources Information Center

    Box, Wilford Winston; Barrett, Anita G.

    A study involving two groups of students enrolled in two concurrent 16-week terms of a course taught at two Southwest Texas Junior College campuses compared the effects of traditional and non-traditional testing. The traditional approach consisted of typical individual testing, while the non-traditional approach involved group testing (i.e., two…

  2. Dispersal and Germination Patterns of Monterey Spineflower at Fort Ord Natural Reserve.

    NASA Astrophysics Data System (ADS)

    Chaudhry, Z.

    2014-12-01

    Some species are rare because they are restricted to certain habitats and/or have small population sizes. Monterey spineflower, a federally listed threatened annual plant, is found in open sandy regions of the California coast, in chaparral vegetation around the Monterey Bay. A model based on previous research suggests that the Monterey spineflower population at Fort Ord Natural Reserve should be rapidly increasing, but it is not. This suggests that the model may be using data that overestimates the percentage of spineflower seeds that successfully germinate. I tested three hypotheses to determine the cause of the difference in population sizes between the predicted model and the field results. First, I predicted that the spineflower seeds are blown by the wind into shrubs such as manzanita, and are unable to germinate due to the lack of a suitable environment. I tested this in two ways. A field experiment showed that seeds are easily blow by wind. Next, I took soil cores and found spineflower seeds within the manzanita shrubs. Secondly, I predicted that the germination rate used by the model (90%) was too high. However, my germination experiments did not support this hypothesis because 91% of new seeds successfully germinated. Lastly, I predicted that the newer seeds are more viable than older seeds and therefore have a higher chance of successfully germinating. After germinating seeds in a controlled environment I observed that the seeds from 2014 had a higher number of successfully germinated seeds compared to the number of successfully germinated seeds from 1995 (91% vs 33%). I conclude that the loss of seeds due to wind decreases germination expectancies and older seeds are less viable than new seeds. Therefore, Monterey spineflower is a rare plant because environmental barriers hinder seeds from dispersing to a suitable habitat and successfully germinating while seeds lose viability as they age.

  3. Campanulaceae: a family with small seeds that require light for germination

    PubMed Central

    Koutsovoulou, Katerina; Daws, Matthew I.; Thanos, Costas A.

    2014-01-01

    Background and Aims The Campanulaceae is a large cosmopolitan family, but is understudied in terms of germination, and seed biology in general. Small seed mass (usually in the range 10–200 µg) is a noteworthy trait of the family, and having small seeds is commonly associated with a light requirement. Thus, the purpose of this study was to investigate the effect of light on germination in 131 taxa of the Campanulaceae family, from all five continents of its distribution. Methods For all taxa, seed germination was tested in light (8 or 12 h photoperiod) and continuous darkness under constant and alternating temperatures. For four taxa, the effect of light on germination was examined over a wide range of temperatures on a thermogradient plate, and the possible substitution of the light requirement by gibberellic acid and nitrate was examined in ten taxa. Key Results For all 131 taxa, seed germination was higher in light than in darkness for every temperature tested. Across species, the light requirement decreased significantly with increasing seed mass. For larger seeded species, germination in the dark reached higher levels under alternating than under constant temperatures. Gibberellic acid promoted germination in darkness whereas nitrates partially substituted for a light requirement only in species showing some dark germination. Conclusions A light requirement for germination, observed in virtually all taxa examined, constitutes a collective characteristic of the family. It is postulated that smaller seeded taxa might germinate only on the soil surface or at shallow depths, while larger seeded species might additionally germinate when buried in the soil if cued to do so by fluctuating temperatures. PMID:24232382

  4. Fast Sterility Assessment by Germinable-Endospore Biodosimetry▿ †

    PubMed Central

    Yung, Pun To; Ponce, Adrian

    2008-01-01

    The increased demand for sterile products has created the need for rapid technologies capable of validating the hygiene of industrial production processes. Bacillus endospores are in standard use as biological indicators for evaluating the effectiveness of sterilization processes. Currently, culture-based methods, requiring more than 2 days before results become available, are employed to verify endospore inactivation. We describe a rapid, microscopy-based endospore viability assay (μEVA) capable of enumerating germinable endospores in less than 15 min. μEVA employs time-gated luminescence microscopy to enumerate single germinable endospores via terbium-dipicolinate (Tb-DPA) luminescence, which is triggered under UV excitation as 108 DPA molecules are released during germination on agarose containing Tb3+ and a germinant (e.g., l-alanine). Inactivation of endospore populations to sterility was monitored with μEVA as a function of thermal and UV dosage. A comparison of culturing results yielded nearly identical decimal reduction values, thus validating μEVA as a rapid biodosimetry method for monitoring sterilization processes. The simple Tb-DPA chemical test for germinability is envisioned to enable fully automated instrumentation for in-line monitoring of hygiene in industrial production processes. PMID:18836020

  5. 7 CFR 201.20 - Germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination for each kind or kind and variety or kind and type of kind and hybrid of agricultural seed...

  6. 7 CFR 201.20 - Germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination each kind, or kind and variety, or kind and type, or kind and hybrid of agricultural seed...

  7. 7 CFR 201.20 - Germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination for each kind or kind and variety or kind and type of kind and hybrid of agricultural seed...

  8. 7 CFR 201.20 - Germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination each kind, or kind and variety, or kind and type, or kind and hybrid of agricultural seed...

  9. 7 CFR 201.20 - Germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination for each kind or kind and variety or kind and type of kind and hybrid of agricultural seed...

  10. Digital Image Correlation Techniques Applied to Large Scale Rocket Engine Testing

    NASA Technical Reports Server (NTRS)

    Gradl, Paul R.

    2016-01-01

    Rocket engine hot-fire ground testing is necessary to understand component performance, reliability and engine system interactions during development. The J-2X upper stage engine completed a series of developmental hot-fire tests that derived performance of the engine and components, validated analytical models and provided the necessary data to identify where design changes, process improvements and technology development were needed. The J-2X development engines were heavily instrumented to provide the data necessary to support these activities which enabled the team to investigate any anomalies experienced during the test program. This paper describes the development of an optical digital image correlation technique to augment the data provided by traditional strain gauges which are prone to debonding at elevated temperatures and limited to localized measurements. The feasibility of this optical measurement system was demonstrated during full scale hot-fire testing of J-2X, during which a digital image correlation system, incorporating a pair of high speed cameras to measure three-dimensional, real-time displacements and strains was installed and operated under the extreme environments present on the test stand. The camera and facility setup, pre-test calibrations, data collection, hot-fire test data collection and post-test analysis and results are presented in this paper.

  11. Impact of seed germination data on genebank management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed viability data on plant genetic resource accessions in cold storage is critical information that impacts many areas of genebank management. Prior to 2002, little germination testing was conducted at the Plant Genetic Resources Conservation Unit (PGRCU), Griffin, GA. Seed was distributed from th...

  12. 76 FR 19952 - Not Applying the Mark of Inspection Pending Certain Test Results

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ... (69 FR 1892), announcing that the Agency would not apply the mark of inspection to any animal carcass... Safety of Juice and Juice Products'' (63 FR 24258; May 1, 1998). \\4\\ The annual figure of $15 million is... Flexibility Analysis of the Proposed Rules to Ensure the Safety of Juice and Juice Products'' (63 FR...

  13. Seed flotation and germination of salt marsh plants: The effects of stratification, salinity, and/or inundation regime

    USGS Publications Warehouse

    Elsey-Quirk, T.; Middleton, B.A.; Proffitt, C.E.

    2009-01-01

    We examined the effects of cold stratification and salinity on seed flotation of eight salt marsh species. Four of the eight species were tested for germination success under different stratification, salinity, and flooding conditions. Species were separated into two groups, four species received wet stratification and four dry stratification and fresh seeds of all species were tested for flotation and germination. Fresh seeds of seven out of eight species had flotation times independent of salinity, six of which had average flotation times of at least 50 d. Seeds of Spartina alterniflora and Spartina patens had the shortest flotation times, averaging 24 and 26 d, respectively. Following wet stratification, the flotation time of S. alterniflora seeds in higher salinity water (15 and 36 ppt) was reduced by over 75% and germination declined by more than 90%. Wet stratification reduced the flotation time of Distichlis spicata seeds in fresh water but increased seed germination from 2 to 16% in a fluctuating inundation regime. Fresh seeds of Iva frutescens and S. alternflora were capable of germination and therefore are non-dormant during dispersal. Fresh seeds of I. frutescens had similar germination to dry stratified seeds ranging 25-30%. Salinity reduced seed germination for all species except for S. alterniflora. A fluctuating inundation regime was important for seed germination of the low marsh species and for germination following cold stratification. The conditions that resulted in seeds sinking faster were similar to the conditions that resulted in higher germination for two of four species. ?? 2009 Elsevier B.V.

  14. Quality assurance of the Applied Knowledge Test (AKT) of the MRCGP examination - an immediate post-test questionnaire evaluation of the candidates' views.

    PubMed

    Dixon, Hilton; Blow, Carol; Milne, Paul; Siriwardena, Niroshan; Milne, Heather; Elfes, Christopher

    2015-07-01

    The Applied Knowledge Test (AKT) of the Membership of the Royal College of General Practitioners (MRCGP) examination is a computer-based assessment delivered three times a year. A computerised questionnaire, administered immediately after the test, sought candidates' views as part of the test evaluation. Of 1681 candidates taking the test 1418 (84%) responded. Most candidates believed that the test assessed their knowledge of problems relevant to general practice. Their feedback highlighted areas where improvements could be made. Candidates' views of postgraduate specialty medical examinations in the UK are rarely sought or published. We are not aware of other published evidence. The use of computer-based testing enables immediate candidate feedback and can be used routinely to evaluate the test validity and formats. The views of candidates are an important component of quality assurance in reviewing the content, format and educational experience of a high-stakes examination. PMID:26253057

  15. Infrared Thermography as Applied to Thermal Testing of Power Systems Circuit Boards.

    NASA Astrophysics Data System (ADS)

    Miles, Jonathan James

    All operational electronic equipment dissipates some amount of energy in the form of infrared radiation. Faulty electronic components on a printed circuit board can be categorized as hard (functional) or soft (latent functional). Hard faults are those which are detected during a conventional manufacturing electronic test process. Soft failures, in contrast, are those which are undetectable through conventional testing, but which manifest themselves after a product has been placed into service. Such field defective modules ultimately result in operational failure and subsequently enter a manufacturer's costly repair process. While thermal imaging systems are being used increasingly in the electronic equipment industry as a product-testing tool, applications have primarily been limited to product design or repair processes, with minimal use in a volume manufacturing environment. Use of thermal imaging systems in such an environment has mostly been limited to low-volume products or random screening of high-volume products. Thermal measurements taken in a manufacturing environment are often taken manually, thus defeating their capability of rapid data acquisition and constraining their full potential in a high-volume manufacturing process. Integration of a thermal measurement system with automated testing equipment is essential for optimal use of expensive infrared measurement tools in a high-volume manufacturing environment. However, such a marriage presents problems with respect to both existing manufacturing test processes and infrared measurement techniques. Methods are presented in this dissertation to test automatically for latent faults, those which elude detection during conventional electronic testing, on printed circuit boards. These methods are intended for implementation in a volume manufacturing environment and involve the application of infrared imaging tools. Successful incorporation of infrared testing into existing test processes requires that: PASS

  16. A high-throughput seed germination assay for root parasitic plants

    PubMed Central

    2013-01-01

    Background Some root-parasitic plants belonging to the Orobanche, Phelipanche or Striga genus represent one of the most destructive and intractable weed problems to agricultural production in both developed and developing countries. Compared with most of the other weeds, parasitic weeds are difficult to control by conventional methods because of their life style. The main difficulties that currently limit the development of successful control methods are the ability of the parasite to produce a tremendous number of tiny seeds that may remain viable in the soil for more than 15 years. Seed germination requires induction by stimulants present in root exudates of host plants. Researches performed on these minute seeds are until now tedious and time-consuming because germination rate is usually evaluated in Petri-dish by counting germinated seeds under a binocular microscope. Results We developed an easy and fast method for germination rate determination based on a standardized 96-well plate test coupled with spectrophotometric reading of tetrazolium salt (MTT) reduction. We adapted the Mosmann’s protocol for cell cultures to germinating seeds and determined the conditions of seed stimulation and germination, MTT staining and formazan salt solubilization required to obtain a linear relationship between absorbance and germination rate. Dose–response analyses were presented as applications of interest for assessing half maximal effective or inhibitory concentrations of germination stimulants (strigolactones) or inhibitors (ABA), respectively, using four parameter logistic curves. Conclusion The developed MTT system is simple and accurate. It yields reproducible results for germination bioassays of parasitic plant seeds. This method is adapted to high-throughput screenings of allelochemicals (stimulants, inhibitors) or biological extracts on parasitic plant seed germination, and strengthens the investigations of distinctive features of parasitic plant germination

  17. Facet theory applied to the construction and validation of the Aachen Aphasia Test.

    PubMed

    Willmes, K; Poeck, K; Weniger, D; Huber, W

    1983-03-01

    The linguistic performance of 120 aphasic patients of the four standard syndromes assessed by the Aachen Aphasia Test (AAT) is analyzed by a nonmetric (ordinal) multidimensional scaling procedure (Smallest Space Analysis, SSA1). The linguistic structure of the test items is characterized within the framework of L. Guttman's facet theory. Three systematic components (facets) are discerned: linguistic modality, unit, and regularity. Properties of the facets as well as their relations are assessed and tested empirically by analyzing the interrelations among different items or sets of items. The spatial configurations obtained by the scaling procedure fit only partially the expectations derived from the facet-theory model. The modality facet was found to have a strong overriding influence on the aphasic test performance. The facets unit and regularity were only found for the most rigorously designed subtests. Written Language and Comprehension. The results suggest the introduction of a new combined facet linguistic complexity which reflects the dependency of the facets regularity and unit.

  18. Exposure-driven risk assessment: applying exposure-based waiving of toxicity tests under REACH.

    PubMed

    Rowbotham, Anna L; Gibson, Rosemary M

    2011-08-01

    The REACH Regulation 1907/2006/EC aims to improve knowledge of the potential risks to humans and the environment of the large number of chemicals produced and used in the EU. The testing requirements are likely to trigger numerous toxicological studies, potentially involving millions of experimental animals, despite the professed goal of REACH to reduce vertebrate testing. It may be necessary therefore to shift emphasis away from animal studies towards more pragmatic strategies, reserving animal tests for the substances of greatest concern. One approach is to waive certain tests based on levels of exposure to the substance. This review explores application of 'Exposure-Based Waiving' (EBW) of toxicity studies, with a particular focus on inhalation where possible, considering the potential qualitative and quantitative supporting arguments that might be made, including the use of thresholds of toxicological concern. Incorporating EBW into intelligent testing strategies for substance registration could advance the goals of REACH and the 3Rs (reduction, replacement and refinement of animals in research) by reducing the usage of animals in toxicity tests, whilst maintaining appropriate protection of human health and the environment. However greater regulatory evaluation, acceptance and guidance are required for EBW to achieve its full impact.

  19. The Relationship of Deep and Surface Study Approaches on Factual and Applied Test-Bank Multiple-Choice Question Performance

    ERIC Educational Resources Information Center

    Yonker, Julie E.

    2011-01-01

    With the advent of online test banks and large introductory classes, instructors have often turned to textbook publisher-generated multiple-choice question (MCQ) exams in their courses. Multiple-choice questions are often divided into categories of factual or applied, thereby implicating levels of cognitive processing. This investigation examined…

  20. Predicting the Future: Opportunities and Challenges for the Chemical Industry to Apply 21st-Century Toxicity Testing

    PubMed Central

    Settivari, Raja S; Ball, Nicholas; Murphy, Lynea; Rasoulpour, Reza; Boverhof, Darrell R; Carney, Edward W

    2015-01-01

    Interest in applying 21st-century toxicity testing tools for safety assessment of industrial chemicals is growing. Whereas conventional toxicology uses mainly animal-based, descriptive methods, a paradigm shift is emerging in which computational approaches, systems biology, high-throughput in vitro toxicity assays, and high-throughput exposure assessments are beginning to be applied to mechanism-based risk assessments in a time- and resource-efficient fashion. Here we describe recent advances in predictive safety assessment, with a focus on their strategic application to meet the changing demands of the chemical industry and its stakeholders. The opportunities to apply these new approaches is extensive and include screening of new chemicals, informing the design of safer and more sustainable chemical alternatives, filling information gaps on data-poor chemicals already in commerce, strengthening read-across methodology for categories of chemicals sharing similar modes of action, and optimizing the design of reduced-risk product formulations. Finally, we discuss how these predictive approaches dovetail with in vivo integrated testing strategies within repeated-dose regulatory toxicity studies, which are in line with 3Rs principles to refine, reduce, and replace animal testing. Strategic application of these tools is the foundation for informed and efficient safety assessment testing strategies that can be applied at all stages of the product-development process. PMID:25836969

  1. 40 CFR 1045.401 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false What testing requirements apply to my engines that have gone into service? 1045.401 Section 1045.401 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION...

  2. 40 CFR 1045.401 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What testing requirements apply to my engines that have gone into service? 1045.401 Section 1045.401 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION...

  3. 40 CFR 1045.401 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false What testing requirements apply to my engines that have gone into service? 1045.401 Section 1045.401 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION...

  4. 40 CFR 1045.401 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What testing requirements apply to my engines that have gone into service? 1045.401 Section 1045.401 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION...

  5. 40 CFR 1045.401 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false What testing requirements apply to my engines that have gone into service? 1045.401 Section 1045.401 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION...

  6. Predicting the future: opportunities and challenges for the chemical industry to apply 21st-century toxicity testing.

    PubMed

    Settivari, Raja S; Ball, Nicholas; Murphy, Lynea; Rasoulpour, Reza; Boverhof, Darrell R; Carney, Edward W

    2015-03-01

    Interest in applying 21st-century toxicity testing tools for safety assessment of industrial chemicals is growing. Whereas conventional toxicology uses mainly animal-based, descriptive methods, a paradigm shift is emerging in which computational approaches, systems biology, high-throughput in vitro toxicity assays, and high-throughput exposure assessments are beginning to be applied to mechanism-based risk assessments in a time- and resource-efficient fashion. Here we describe recent advances in predictive safety assessment, with a focus on their strategic application to meet the changing demands of the chemical industry and its stakeholders. The opportunities to apply these new approaches is extensive and include screening of new chemicals, informing the design of safer and more sustainable chemical alternatives, filling information gaps on data-poor chemicals already in commerce, strengthening read-across methodology for categories of chemicals sharing similar modes of action, and optimizing the design of reduced-risk product formulations. Finally, we discuss how these predictive approaches dovetail with in vivo integrated testing strategies within repeated-dose regulatory toxicity studies, which are in line with 3Rs principles to refine, reduce, and replace animal testing. Strategic application of these tools is the foundation for informed and efficient safety assessment testing strategies that can be applied at all stages of the product-development process.

  7. Germination of cysts in acetabularia mediterranea.

    PubMed

    Koop, H U

    1975-01-01

    Techniques for the growth of uniformly reacting populations of cysts of Acetabularia mediterranea and for quantitative measurement of cyst germination have been developed. Cysts of A. mediterranea can be induced to germinated by exposure to the atmosphere. Germination rates are very low in young cysts. They increased during exposure to total darkness. This "maturation of cysts" is found to be completed after a period of 12-15 weeks. Germination rates of cysts that have passed the maturation period exceed 90 percent in continuous white light and 80 percent in darkness. Cysts germinate in less than two days in darkness and less than four days in light. The influence of temperature at a range of 15 degrees C to 25 degrees C on germination kinetics is studied in light and darkness. Germination is accelerated with increasing temperature up to 21 degrees C. At higher temperature germination is delayed in light but the time of germination remains constant in darknesss. Rates of germination are not altered by the influence of temperature in light while in darkness there is a dramatic decrease at temperatures higher than 21 degrees C. From these findings it is concluded that cyst germinationA. mediteranea does not need any light but is influenced by light dependent systems. The influence of light is strongest at elevated temperatures.

  8. Applying Adverse Outcome Pathways (AOPs) to support Integrated Approaches to Testing and Assessment (IATA).

    PubMed

    Tollefsen, Knut Erik; Scholz, Stefan; Cronin, Mark T; Edwards, Stephen W; de Knecht, Joop; Crofton, Kevin; Garcia-Reyero, Natalia; Hartung, Thomas; Worth, Andrew; Patlewicz, Grace

    2014-12-01

    Chemical regulation is challenged by the large number of chemicals requiring assessment for potential human health and environmental impacts. Current approaches are too resource intensive in terms of time, money and animal use to evaluate all chemicals under development or already on the market. The need for timely and robust decision making demands that regulatory toxicity testing becomes more cost-effective and efficient. One way to realize this goal is by being more strategic in directing testing resources; focusing on chemicals of highest concern, limiting testing to the most probable hazards, or targeting the most vulnerable species. Hypothesis driven Integrated Approaches to Testing and Assessment (IATA) have been proposed as practical solutions to such strategic testing. In parallel, the development of the Adverse Outcome Pathway (AOP) framework, which provides information on the causal links between a molecular initiating event (MIE), intermediate key events (KEs) and an adverse outcome (AO) of regulatory concern, offers the biological context to facilitate development of IATA for regulatory decision making. This manuscript summarizes discussions at the Workshop entitled "Advancing AOPs for Integrated Toxicology and Regulatory Applications" with particular focus on the role AOPs play in informing the development of IATA for different regulatory purposes. PMID:25261300

  9. Interrelationship of Nondestructive Evaluation Methodologies Applied to Testing of Composite Overwrapped Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Leifeste, Mark R.

    2007-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are commonly used in spacecraft for containment of pressurized gases and fluids, incorporating strength and weight savings. The energy stored is capable of extensive spacecraft damage and personal injury in the event of sudden failure. These apparently simple structures, composed of a metallic media impermeable liner and fiber/resin composite overwrap are really complex structures with numerous material and structural phenomena interacting during pressurized use which requires multiple, interrelated monitoring methodologies to monitor and understand subtle changes critical to safe use. Testing of COPVs at NASA Johnson Space Center White Sands T est Facility (WSTF) has employed multiple in-situ, real-time nondestructive evaluation (NDE) methodologies as well as pre- and post-test comparative techniques to monitor changes in material and structural parameters during advanced pressurized testing. The use of NDE methodologies and their relationship to monitoring changes is discussed based on testing of real-world spacecraft COPVs. Lessons learned are used to present recommendations for use in testing, as well as a discussion of potential applications to vessel health monitoring in future applications.

  10. Applying Choice Architecture Principles to Understand HIV Testing: Findings From Malawi and Zimbabwe.

    PubMed

    Chung, Adrienne H; Rimal, Rajiv N

    2015-08-01

    Improvements spearheaded by the World Health Organization in antenatal HIV counseling in sub-Saharan Africa from 2004 to 2011 have seen a parallel increase in HIV testing. We sought to determine the extent to which the use of choice architecture principles (one that introduces an opt-out option as the default) affect uptake of HIV testing, above and beyond individual-level attitudes and cognitions. Demographic and Health Survey data collected between 2004 and 2011 from Zimbabwe (N = 1,330) and Malawi (N = 4,043)--countries where over 10% of adults have HIV--were analyzed. We explored the influence of demographic variables, modes of knowledge about HIV, stigma against people living with HIV, attitudes about spousal abuse, and whether or not HIV testing had been offered during antenatal visits. Results demonstrated that, taking into account secular trends in higher testing rates, structural-level support was the strongest predictor of HIV testing above and beyond individual-level attitudes and cognitions. PMID:26241385

  11. Applying Adverse Outcome Pathways (AOPs) to support Integrated Approaches to Testing and Assessment (IATA).

    PubMed

    Tollefsen, Knut Erik; Scholz, Stefan; Cronin, Mark T; Edwards, Stephen W; de Knecht, Joop; Crofton, Kevin; Garcia-Reyero, Natalia; Hartung, Thomas; Worth, Andrew; Patlewicz, Grace

    2014-12-01

    Chemical regulation is challenged by the large number of chemicals requiring assessment for potential human health and environmental impacts. Current approaches are too resource intensive in terms of time, money and animal use to evaluate all chemicals under development or already on the market. The need for timely and robust decision making demands that regulatory toxicity testing becomes more cost-effective and efficient. One way to realize this goal is by being more strategic in directing testing resources; focusing on chemicals of highest concern, limiting testing to the most probable hazards, or targeting the most vulnerable species. Hypothesis driven Integrated Approaches to Testing and Assessment (IATA) have been proposed as practical solutions to such strategic testing. In parallel, the development of the Adverse Outcome Pathway (AOP) framework, which provides information on the causal links between a molecular initiating event (MIE), intermediate key events (KEs) and an adverse outcome (AO) of regulatory concern, offers the biological context to facilitate development of IATA for regulatory decision making. This manuscript summarizes discussions at the Workshop entitled "Advancing AOPs for Integrated Toxicology and Regulatory Applications" with particular focus on the role AOPs play in informing the development of IATA for different regulatory purposes.

  12. Testing the Pareto against the lognormal distributions with the uniformly most powerful unbiased test applied to the distribution of cities.

    PubMed

    Malevergne, Yannick; Pisarenko, Vladilen; Sornette, Didier

    2011-03-01

    Fat-tail distributions of sizes abound in natural, physical, economic, and social systems. The lognormal and the power laws have historically competed for recognition with sometimes closely related generating processes and hard-to-distinguish tail properties. This state-of-affair is illustrated with the debate between Eeckhout [Amer. Econ. Rev. 94, 1429 (2004)] and Levy [Amer. Econ. Rev. 99, 1672 (2009)] on the validity of Zipf's law for US city sizes. By using a uniformly most powerful unbiased (UMPU) test between the lognormal and the power-laws, we show that conclusive results can be achieved to end this debate. We advocate the UMPU test as a systematic tool to address similar controversies in the literature of many disciplines involving power laws, scaling, "fat" or "heavy" tails. In order to demonstrate that our procedure works for data sets other than the US city size distribution, we also briefly present the results obtained for the power-law tail of the distribution of personal identity (ID) losses, which constitute one of the major emergent risks at the interface between cyberspace and reality. PMID:21517562

  13. Testing the Pareto against the lognormal distributions with the uniformly most powerful unbiased test applied to the distribution of cities

    NASA Astrophysics Data System (ADS)

    Malevergne, Yannick; Pisarenko, Vladilen; Sornette, Didier

    2011-03-01

    Fat-tail distributions of sizes abound in natural, physical, economic, and social systems. The lognormal and the power laws have historically competed for recognition with sometimes closely related generating processes and hard-to-distinguish tail properties. This state-of-affair is illustrated with the debate between Eeckhout [Amer. Econ. Rev.SCIEAS0002-828210.1257/0002828043052303 94, 1429 (2004)] and Levy [Amer. Econ. Rev.SCIEAS0002-828210.1257/aer.99.4.1672 99, 1672 (2009)] on the validity of Zipf’s law for US city sizes. By using a uniformly most powerful unbiased (UMPU) test between the lognormal and the power-laws, we show that conclusive results can be achieved to end this debate. We advocate the UMPU test as a systematic tool to address similar controversies in the literature of many disciplines involving power laws, scaling, “fat” or “heavy” tails. In order to demonstrate that our procedure works for data sets other than the US city size distribution, we also briefly present the results obtained for the power-law tail of the distribution of personal identity (ID) losses, which constitute one of the major emergent risks at the interface between cyberspace and reality.

  14. Innovative vibration technique applied to polyurethane foam as a viable substitute for conventional fatigue testing

    NASA Astrophysics Data System (ADS)

    Peralta, Alexander; Just-Agosto, Frederick; Shafiq, Basir; Serrano, David

    2012-12-01

    Lifetime prediction using three-point bending (TPB) can at times be prohibitively time consuming and costly, whereas vibration testing at higher frequency may potentially save time and revenue. A vibration technique that obtains lifetimes that reasonably match those determined under flexural TPB fatigue is developed. The technique designs the specimen with a procedure based on shape optimization and finite element analysis. When the specimen is vibrated in resonance, a stress pattern that mimics the stress pattern observed under conventional TPB fatigue testing is obtained. The proposed approach was verified with polyurethane foam specimens, resulting in an average error of 4.5% when compared with TPB.

  15. Seed dormancy and germination of Ficus lundellii and tropical forest restoration.

    PubMed

    Garcia, Ximena; Hong, Tran D; Ellis, Richard H

    2006-01-01

    We investigated seed dormancy and germination in Ficus lundellii Standl. (Moraceae), a native species of Mexico's Los Tuxtlas tropical rain forest. In an 8-h photoperiod at an alternating diurnal (16/8 h) temperature of 20/30 degrees C, germination was essentially complete (96%) within 28 days, whereas in darkness, all seeds remained dormant. Neither potassium nitrate (0.05-0.2%) applied continuously nor gibberellic acid applied either continuously (10-200 ppm) or as a 24 hour pretreatment (2000 ppm) induced germination in the dark. Germination in the light was not reduced by a 24-h hydrochloric acid (0.1-1%) pretreatment, but it was reduced both by a 24-h pretreatment with either H(2)O(2) (0.1-5 M) or 5% HCl, or by more than 5 days of storage at 40 degrees C (4.5% seed water content). In a study with a 2-dimensional temperature gradient plate, seeds germinated fully and rapidly in the light at a constant temperature of 30 degrees C, and fully but less rapidly in the light at alternating temperatures with low amplitudes (< 12 degrees C) about the optimal constant temperature. The base, optimal and ceiling temperatures for rate of germination were estimated as 13.8, 30.1 and 41.1 degrees C, respectively. In all temperature regimes, light was essential for the germination of F. lundellii seeds.

  16. Germination Shifts of C3 and C4 Species under Simulated Global Warming Scenario

    PubMed Central

    Zhang, Hongxiang; Yu, Qiang; Huang, Yingxin; Zheng, Wei; Tian, Yu; Song, Yantao; Li, Guangdi; Zhou, Daowei

    2014-01-01

    Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination) of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night) and symmetric warming (+5/+5°C at day/night), simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature), maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies. PMID:25137138

  17. Germination shifts of C3 and C4 species under simulated global warming scenario.

    PubMed

    Zhang, Hongxiang; Yu, Qiang; Huang, Yingxin; Zheng, Wei; Tian, Yu; Song, Yantao; Li, Guangdi; Zhou, Daowei

    2014-01-01

    Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination) of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night) and symmetric warming (+5/+5°C at day/night), simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature), maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies.

  18. [Effect of acid rain on seed germination of rice, wheat and rape].

    PubMed

    Zeng, Qing-ling; Huang, Xiao-hua; Zhou, Qing

    2005-01-01

    Rice, wheat and rape seeds were treated with simulated acid rain at pH 2.0, 2.5, 3.0, 3.5, 4.0 and 5.0 levels for 7 days in order to understand the effects of acid rain on seed germination of various acid-fast plant. The germination test showed that seed germination was absolutely inhibited at pH 2.0 for three species. Rice and wheat seeds germinated abnormally at pH 2.5. WhenpH values above 3.0, percentage germination, germination energy, germination index, vigor index of rice, wheat and rape seeds increased in relation with decreased acidity levels. In contrast, the percentage of abnormal germination of rice and wheat decreased. The experiment data about physiological aspect demonstrated that water absorption rate, respiratory rate and storage reserve transformation rate of rice, wheat and rape seeds also increased with increased pH values. The storage loss of rice and wheat increased with increased pH values but that of rape decreased. Inhibition index of shoot and root length of three kinds of seeds decreased in relation with increased pH values. The amplitude difference of index of rice was lower than that of wheat, and wheat was lower than that of rape. The experiment data showed that rice had stronger fastness than wheat and rape, wheat had stronger fastness than rape under acid rain stress.

  19. Applying Tests of Equivalence for Multiple Group Comparisons: Demonstration of the Confidence Interval Approach

    ERIC Educational Resources Information Center

    Rusticus, Shayna A.; Lovato, Chris Y.

    2011-01-01

    Assessing the comparability of different groups is an issue facing many researchers and evaluators in a variety of settings. Commonly, null hypothesis significance testing (NHST) is incorrectly used to demonstrate comparability when a non-significant result is found. This is problematic because a failure to find a difference between groups is not…

  20. Developing and Testing an Online Tool for Teaching GIS Concepts Applied to Spatial Decision-Making

    ERIC Educational Resources Information Center

    Carver, Steve; Evans, Andy; Kingston, Richard

    2004-01-01

    The development and testing of a Web-based GIS e-learning resource is described. This focuses on the application of GIS for siting a nuclear waste disposal facility and the associated principles of spatial decision-making using Boolean and weighted overlay methods. Initial student experiences in using the system are analysed as part of a research…

  1. Investigating Content and Face Validity of English Language Placement Test Designed by Colleges of Applied Sciences

    ERIC Educational Resources Information Center

    Al-Adawi, Sharifa S. A.; Al-Balushi, Aaisha A. K.

    2016-01-01

    An English placement test (PT) is an essential component of any foundation program. It helps place students into their suitable language proficiency level so that they do not spend time learning materials below or above their levels. It also helps teachers to prepare teaching materials to students of similar levels (Brown, 2004; Illinois, 2012).…

  2. Genetic Algorithm Based Multi-Agent System Applied to Test Generation

    ERIC Educational Resources Information Center

    Meng, Anbo; Ye, Luqing; Roy, Daniel; Padilla, Pierre

    2007-01-01

    Automatic test generating system in distributed computing context is one of the most important links in on-line evaluation system. Although the issue has been argued long since, there is not a perfect solution to it so far. This paper proposed an innovative approach to successfully addressing such issue by the seamless integration of genetic…

  3. In vitro chemical and cellular tests applied to uranium trioxide with different hydration states.

    PubMed Central

    Ansoborlo, E; Chalabreysse, J; Hengé-Napoli, M H; Pujol, E

    1992-01-01

    A simple and rapid in vitro chemical solubility test applicable to industrial uranium trioxide (UO3) was developed together with two in vitro cellular tests using rat alveolar macrophages maintained either in gas phase or in alginate beads at 37 degrees C. Industrial UO3 was characterized by particle size, X-ray, and IR spectra, and chemical transformation (e.g., aging and hydration of the dust) was also studied. Solvents used for the in vitro chemical solubility study included carbonates, citrates, phosphates, water, Eagle's basal medium, and Gamble's solution (simulated lung fluid), alone, with oxygen, or with superoxide ions. Results, expressed in terms of the half-time of dissolution, according to International Commission on Radiological Protection (ICRP) classification (D,W,Y), varied for different hydration states of UO3, showing a lower solubility of hydrated UO3 in solvents compared to basic UO3 or UO3 heated at 450 degrees C. Two in vitro cellular tests on cultured rat alveolar macrophages (cells maintained in gas phase and cells immobilized in alginate beads) were used on the same UO3 samples and generally showed a lower solution transfer rate in the presence of macrophages than in the culture medium alone. The results of in vitro chemical and cellular tests were compared, with four main conclusions: a good reproducibility of the three tests in Eagle's basal medium the effect of hydration state on solubility, the classification of UO3 in terms of ICRP solubility criteria, and the ability of macrophages to decrease uranium solubility in medium. PMID:1396449

  4. Fracture toughness of bleached enamel: Effect of applying three different nanobiomaterials by nanoindentation test

    PubMed Central

    Khoroushi, Maryam; Mazaheri, Hamid; Saneie, Tahere; Samimi, Pouran

    2016-01-01

    Background: Despite the absence of dispute about the efficacy of bleaching agents, a prime concern is about their compromising effect on the enamel structure. This in vitro study investigated whether the addition of three different biomaterials, including nano-bioactive glass (n-BG)/nano-hydroxy apetite (n-HA)/nano-amorphous calcium phosphate (n-ACP), to bleaching agents can affect the fracture toughness (FT) and vickers hardness number (VHN) of bovine enamel. Materials and Methods: The crowns of the newly extracted permanent bovine incisors teeth were separated from the root and sectioned along their central line; one half serving as the control specimen and the other half as the test specimen. After mounting and polishing procedure, all the control specimens (C) were subjected to nano-indentation test to obtain the baseline values of FT. Then, the control specimens were exposed to a 38% hydrogen peroxide for four times, each time for 10 min. The test specimens were divided into three groups and treated as follows, with the same protocol used for the control specimens: Group 1; ACP + hydrogen peroxide (HP) mixed gel; Group 2 BG + HP mixed gel; and Group 3 HA + HP mixed gel. FT measurements with nano-indentation were carried out subsequent to bleaching experiments. Data were analyzed using SPSS and Kruskal–Wallis test (α = 0.05). Results: A significant difference in young's modulus (YM), VHN, and FT at baseline and subsequent to bleaching in control group was observed. However, no significant differences were found in YM, VHN, and FT between the test groups, compared to the respective baseline values. Conclusion: Under the limitations of the current study, it can be concluded that the n-HA, n-ACP, and n-BG could be potential biomaterials used to reduce the adverse effects of tooth bleaching. PMID:27307669

  5. Modulation of germination and growth of plants by meditation.

    PubMed

    Haid, M; Huprikar, S

    2001-01-01

    So called primitive peoples of the world share a philosophy that human interaction via ceremony or ritual can affect the natural world. Is it possible to affect the germination and growth of plants by imbuing them with an intent to stimulate or inhibit them? We conducted a double blind series of experiments to determine whether a process of meditation on the water (referred to as "treated") given to a controlled planting of green peas or wheat would affect their germination. Peas were given water treated with stimulating intent. Statistical analysis was done using contingency table, Fisher's test, and Mantel-Haenszel analysis. The germination rate of 504 seeds receiving treated water with stimulating intent was 60.3% compared to 51.8% for the 504 controls (p = 0.006, 0.047, 0.003 respectively). A similar experiment was conducted with wheat with the intent of inhibiting germination. The germination rate of 2970 wheat seeds receiving treated water with inhibitory intent was 70.7% versus 74.9% for 2970 controls (p < 0.001, 0.0001, 0.001 respectively). During the sixth run of the wheat (inhibition) experiment, the seedlings were harvested and individually weighed on the tenth day after planting to determine whether there was any difference in growth. The mass of the treated seedlings was statistically significantly lower (mean = 97 mg versus 106 mg for the controls) when compared by analysis of variance (p = 0.000056). We conclude that meditation upon the water supplied to green peas and wheat can affect their germination rates and growth.

  6. Habitat specialization through germination cueing: a comparative study of herbs from forests and open habitats

    PubMed Central

    ten Brink, Dirk-Jan; Hendriksma, Harmen Pieter; Bruun, Hans Henrik

    2013-01-01

    Background and Aims This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently accompanied by specialization in their regeneration niche; and (2) species are thereby adapted to utilize different windows of opportunity in time (season) and space (habitat). Methods Seed germination response to temperature, light and stratification was tested for 17 congeneric pairs, each consisting of one forest species and one open-habitat species. A factorial design was used with temperature levels and diurnal temperature variation (10 °C constant, 15–5 °C fluctuating, 20 °C constant, 25–15 °C fluctuating), and two light levels (light and darkness) and a cold stratification treatment. The congeneric species pair design took phylogenetic dependence into account. Key Results Species from open habitats germinated better at high temperatures, whereas forest species performed equally well at low and high temperatures. Forest species tended to germinate only after a period of cold stratification that could break dormancy, while species from open habitats generally germinated without cold stratification. The empirically derived germination strategies correspond quite well with establishment opportunities for forest and open-habitat plant species in nature. Conclusions Annual changes in temperature and light regime in temperate forest delimit windows of opportunity for germination and establishment. Germination strategies of forest plants are adaptations to utilize such narrow windows in time. Conversely, lack of fit between germination ecology and environment may explain why species of open habitats generally fail to establish in forests. Germination strategy should be considered an important mechanism for habitat specialization in temperate herbs

  7. Analysis of thermal dependence on the germination of braquiarão seeds using the thermal time model.

    PubMed

    Nakao, E A; Cardoso, V J M

    2016-02-01

    This paper analyzed the thermal dependence on the germination of Urochloa brizantha (Stapf) Webster seeds under constant and fluctuating temperatures through the thermal time model. Germination tests were carried out at constant temperatures ranging from 8 °C to 41.5 °C in order to determine the model parameters: base (Tb), optimal (To) and maximum temperature (Tc) for germination; and the thermal time (θT) required for individual seeds to germinate. Braquiarão seeds germinate within a temperature interval from 8 °C to 41.5 °C, with an optimum range for germination estimated at 31.5 ° ≤ T ≤ 34.5 °C. Actual and expected distributions of cumulative germination percentages of U. brizantha seeds put to germinate both under controlled and uncontrolled temperature regimes were compared, and it can be seen that the model described relatively well the germination at isothermal assays; however the model failed to predict germination at a wide range of thermal fluctuations. Possible explanations for the results are discussed.

  8. Germination conditions affect physicochemical properties of germinated brown rice flour.

    PubMed

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Piyachomkwan, Kuakoon; Tungtrakul, Patcharee; Prinyawiwatkul, Witoon

    2009-01-01

    Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA. PMID:20492098

  9. Imaging Local Chemical Microstructure of Germinated Wheat with Synchrotron Infrared Microspectroscopy

    SciTech Connect

    Koc,H.; Wetzel, D.

    2008-01-01

    The spatial resolution enabled by in situ Fourier-transform infrared (FT-IR) microspectroscopy as predicted from our earlier report in Spectroscopy (1) is applied to localized chemical analysis in this vital biological process of seed germination. Germination includes several different biochemical and structural processes. Ultimately, the entire seed is consumed in sustaining the new life that results after sprouting and growth (2-4). Alpha amylase production is the standard evidence for detection of sprouted (germinated) wheat at harvest. Moist preharvest conditions can cause devastating losses and render the harvested wheat unfit for flour production. Dormancy of dry seeds following harvest retards sprouting under proper storage.

  10. Remarks on Some Mechanical Small-Scale Tests Applied to Properties of Materials

    NASA Astrophysics Data System (ADS)

    Cardu, Marilena; Seccatore, Jacopo

    2016-06-01

    The paper presents the results of test campaigns on small-scale strength properties (particularly, micro-hardness) performed on two homogeneous materials: calcite, a very common and widespread mineral that is characterized by its relatively low Mohs hardness and its high reactivity with even weak acids; and glass, an amorphous solid characterized by the absence of the long-range order which defines crystalline materials. After a synthetic description of the principles underlying two of the three classical comminution laws, known as Kick's law and Rittinger's law, experimental results are discussed. The results of the tests performed show that both scale effect and size effect contribute to the non-constancy of mechanical properties at small scale for crystalline materials. On the other hand, for amorphous materials, a theoretical law considering size effects gives considerably different results from empirical measurements. Considerations and an extended discussion address these findings.

  11. System Integral Test by BWR Drywell Cooler Applied as Phase-II Accident Management

    SciTech Connect

    Nagasaka, Hideo; Tobimatsu, Toshimi; Tahara, Mika; Yokobori, Seiichi; Akinaga, Makoto

    2002-07-01

    This paper deals with the system interaction performance using the BWR drywell local cooler (DWC) in combination with containment spray as a Japanese Phase-II accident management (AM). By using almost full height simulation test facility (GIRAFFE-DWC) with scaling ratio of 1/600, the system integral tests simulating BWR low pressure vessel failure sequence were accomplished during about 14 hours. In case of DWC application, the containment pressure increase was found milder due to DWC heat removal performance. Initial spray timing was delayed about 3 hours and each spray period was reduced almost by half. It was concluded that the application of a BWR DWC to Phase-II AM measure is quite promising from the point of delaying or preventing the containment venting. (authors)

  12. Why Johnnie Can't Apply Neuroscience: Testing Alternative Hypotheses Using Performance-Based Assessment.

    PubMed

    Mavis, Brian E.; Lovell, Kathryn L.; Ogle, Karen S.

    1998-01-01

    When second year medical students were less successful than expected in solving an OSCE neurologic case, a subsequent performance-based assessment was modified to permit testing of four hypotheses related to knowledge application, ability decay over time, skill performance, and case complexity. Two cohorts of second year medical students were presented with neurologic cases in the context of performance-based assessment. Although many students demonstrated that they had the requisite knowledge, few were able to access the knowledge in less structured testing formats. Students had the skills necessary to conduct a physical examination but were unable to appropriately focus the examination. Case complexity also was related to some performance domains. There was evidence of knowledge and skill decay over time. In summary, it is apparent that multiple factors influence students' performance and are important considerations in designing performance assessments to evaluate competence.

  13. An empirical test of the Theory of Planned Behaviour applied to contraceptive use in rural Uganda.

    PubMed

    Kiene, Susan M; Hopwood, Sarah; Lule, Haruna; Wanyenze, Rhoda K

    2014-12-01

    There is a high unmet need for contraceptives in developing countries such as Uganda, with high population growth, where efforts are needed to promote family planning and contraceptive use. Despite this high need, little research has investigated applications of health-behaviour-change theories to contraceptive use among this population. This study tested the Theory of Planned Behaviour's ability to predict contraceptive-use-related behaviours among post-partum women in rural Uganda. Results gave modest support to the theory's application and suggest an urgent need for improved theory-based interventions to promote contraceptive use in the populations of developing countries.

  14. An applied test of the social learning theory of deviance to college alcohol use.

    PubMed

    DeMartino, Cynthia H; Rice, Ronald E; Saltz, Robert

    2015-04-01

    Several hypotheses about influences on college drinking derived from the social learning theory of deviance were tested and confirmed. The effect of ethnicity on alcohol use was completely mediated by differential association and differential reinforcement, whereas the effect of biological sex on alcohol use was partially mediated. Higher net positive reinforcements to costs for alcohol use predicted increased general use, more underage use, and more frequent binge drinking. Two unexpected finding were the negative relationship between negative expectations and negative experiences, and the substantive difference between nondrinkers and general drinkers compared with illegal or binge drinkers. The discussion considers implications for future campaigns based on Akers's deterrence theory.

  15. An applied test of the social learning theory of deviance to college alcohol use.

    PubMed

    DeMartino, Cynthia H; Rice, Ronald E; Saltz, Robert

    2015-04-01

    Several hypotheses about influences on college drinking derived from the social learning theory of deviance were tested and confirmed. The effect of ethnicity on alcohol use was completely mediated by differential association and differential reinforcement, whereas the effect of biological sex on alcohol use was partially mediated. Higher net positive reinforcements to costs for alcohol use predicted increased general use, more underage use, and more frequent binge drinking. Two unexpected finding were the negative relationship between negative expectations and negative experiences, and the substantive difference between nondrinkers and general drinkers compared with illegal or binge drinkers. The discussion considers implications for future campaigns based on Akers's deterrence theory. PMID:25630048

  16. An Empirical Test of the Theory of Planned Behaviour Applied to Contraceptive Use in Rural Uganda

    PubMed Central

    Kiene, Susan M.; Hopwood, Sarah; Lule, Haruna; Wanyenze, Rhoda K.

    2013-01-01

    There is a high unmet need for contraceptives in developing countries such as Uganda, with high population growth, where efforts are needed to promote family planning and contraceptive use. Despite this high need, little research has investigated applications of health behaviour change theories to contraceptive use amongst this population. The present study tested the Theory of Planned Behaviour’s ability to predict contraceptive use-related behaviours among postpartum women in rural Uganda. Results gave modest support to the theory’s application and suggest an urgent need for improved theory-based interventions to promote contraceptive use in the populations of developing countries. PMID:23928989

  17. An empirical test of the Theory of Planned Behaviour applied to contraceptive use in rural Uganda.

    PubMed

    Kiene, Susan M; Hopwood, Sarah; Lule, Haruna; Wanyenze, Rhoda K

    2014-12-01

    There is a high unmet need for contraceptives in developing countries such as Uganda, with high population growth, where efforts are needed to promote family planning and contraceptive use. Despite this high need, little research has investigated applications of health-behaviour-change theories to contraceptive use among this population. This study tested the Theory of Planned Behaviour's ability to predict contraceptive-use-related behaviours among post-partum women in rural Uganda. Results gave modest support to the theory's application and suggest an urgent need for improved theory-based interventions to promote contraceptive use in the populations of developing countries. PMID:23928989

  18. An eigenvector-based test for local stationarity applied to array processing.

    PubMed

    Quijano, Jorge E; Zurk, Lisa M

    2014-06-01

    In sonar array processing, a challenging problem is the estimation of the data covariance matrix in the presence of moving targets in the water column, since the time interval of data local stationarity is limited. This work describes an eigenvector-based method for proper data segmentation into intervals that exhibit local stationarity, providing data-driven higher bounds for the number of snapshots available for computation of time-varying sample covariance matrices. Application of the test is illustrated with simulated data in a horizontal array for the detection of a quiet source in the presence of a loud interferer.

  19. Homothallic sexual reproduction of Pustula helianthicola and germination of oospores.

    PubMed

    Lava, Sukanya Soonagahalli; Spring, Otmar

    2012-09-01

    Sunflower white blister rust has become an important disease in many countries with intensive cultivation of the important oil crop. The biology of the pathogen is still partly unclear, particular with respect to its sexual reproduction and primary mode of infection. Zoospores released from sporangia of Pustula helianthicola were isolated individually and used for the inoculation of sunflower in order to generate unithallic, genetically homogenous infections. Single zoospore inoculation of young seedlings resulted in mitotic sporulation within subepidermal blisters on cotyledons and true leaves after approximately 2 weeks. Three weeks postinoculation, the infected plants started forming oospores, hence indicating homothallic sexual reproduction of the pathogen. The development of oogonia and antheridia was studied using light and fluorescence microscopy. Oospores were isolated from infected plant tissue and used for infection and germination studies. Microscopic observation of isolated oospores showed germination that formed sessile vesicle-like structures, germ sporangia or only germ tubes. The rate of germination reached approximately 40 %. Germination was not dependant on a resting phase after oospore formation. Oospores applied to the above ground parts of sunflower seedlings lead to infections within a similar time frame as was achieved with mitotic sporangia. The results underline the importance of oospores for primary infection at the beginning of the season and for long-distance dispersal of the pathogen with sunflower seeds contaminated by oospores.

  20. What words and where? Applying usability testing techniques to name a new live reference service

    PubMed Central

    Duncan, Vicky; Fichter, Darlene M.

    2004-01-01

    Objective: A user-focused design approach was taken to develop a new “live reference” service at the Health Sciences Library, University of Saskatchewan. The name of the service, the placement of the links, and the design of a graphical button were seen as key elements in creating service awareness and its subsequent use. Methods: To ensure library users recognized and understood the label for the new service, selected library users were given an opportunity to choose a phrase that would best describe the service. The top two preferred phrases were then placed on the library Web pages as text and graphic images for further testing. Some pages had links in multiple locations to determine which placement worked best. Task-based usability testing was carried out with participants who were unaware of the new service. Participants were observed as they completed seven Website tasks arranged in increasing levels of difficulty to see whether they would notice the live reference service and seek assistance. Results: The high level of recognition and use of the service indicate that the label name and link placement were effective with library Website users. Conclusions: Using user-centered design methodology helped ensure that the new live reference service was visible and used and demonstrated the effectiveness of the user-centered design approach for adding new services to an existing Website. PMID:15098051

  1. Geographic profiling applied to testing models of bumble-bee foraging

    PubMed Central

    Raine, Nigel E.; Rossmo, D. Kim; Le Comber, Steven C.

    2008-01-01

    Geographic profiling (GP) was originally developed as a statistical tool to help police forces prioritize lists of suspects in investigations of serial crimes. GP uses the location of related crime sites to make inferences about where the offender is most likely to live, and has been extremely successful in criminology. Here, we show how GP is applicable to experimental studies of animal foraging, using the bumble-bee Bombus terrestris. GP techniques enable us to simplify complex patterns of spatial data down to a small number of parameters (2–3) for rigorous hypothesis testing. Combining computer model simulations and experimental observation of foraging bumble-bees, we demonstrate that GP can be used to discriminate between foraging patterns resulting from (i) different hypothetical foraging algorithms and (ii) different food item (flower) densities. We also demonstrate that combining experimental and simulated data can be used to elucidate animal foraging strategies: specifically that the foraging patterns of real bumble-bees can be reliably discriminated from three out of nine hypothetical foraging algorithms. We suggest that experimental systems, like foraging bees, could be used to test and refine GP model predictions, and that GP offers a useful technique to analyse spatial animal behaviour data in both the laboratory and field. PMID:18664426

  2. Blade Displacement Measurement Technique Applied to a Full-Scale Rotor Test

    NASA Technical Reports Server (NTRS)

    Abrego, Anita I.; Olson, Lawrence E.; Romander, Ethan A.; Barrows, Danny A.; Burner, Alpheus W.

    2012-01-01

    Blade displacement measurements using multi-camera photogrammetry were acquired during the full-scale wind tunnel test of the UH-60A Airloads rotor, conducted in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel. The objectives were to measure the blade displacement and deformation of the four rotor blades as they rotated through the entire rotor azimuth. These measurements are expected to provide a unique dataset to aid in the development and validation of rotorcraft prediction techniques. They are used to resolve the blade shape and position, including pitch, flap, lag and elastic deformation. Photogrammetric data encompass advance ratios from 0.15 to slowed rotor simulations of 1.0, thrust coefficient to rotor solidity ratios from 0.01 to 0.13, and rotor shaft angles from -10.0 to 8.0 degrees. An overview of the blade displacement measurement methodology and system development, descriptions of image processing, uncertainty considerations, preliminary results covering static and moderate advance ratio test conditions and future considerations are presented. Comparisons of experimental and computational results for a moderate advance ratio forward flight condition show good trend agreements, but also indicate significant mean discrepancies in lag and elastic twist. Blade displacement pitch measurements agree well with both the wind tunnel commanded and measured values.

  3. Bioremediation of HCH-contaminated soil: elimination of inhibitory effects of the insecticide on radish and green gram seed germination.

    PubMed

    Bidlan, Rajkumar; Afsar, Mohammed; Manonmani, H K

    2004-08-01

    The effects of technical grade hexachlorocyclohexane (tech-HCH) on the germination of different seeds were tested. Two types of seeds, radish and green gram showed marked reduction in germination percentage and seeding vigour index. The abnormalities and reduction in germination increased with increasing concentration of tech-HCH. At 100 microg HCH level the germination of radish and green gram seeds was inhibited almost completely on moist filter paper and soil. Protease and amylase activities were reduced in seeds grown in soil spiked with tech-HCH. Bioremediation of HCH-spiked soils with a HCH-degrading microbial consortium helped in eliminating the toxic effects of tech-HCH towards seed germination. The degradation of 25 microg tech-HCH g(-1) soil was complete by 120 h. The seed germination and the activities of the assayed enzymes, amylase and protease, were same as before or better in bioremediated soils.

  4. Pilot-testing an applied competency-based approach to health human resources planning.

    PubMed

    Tomblin Murphy, Gail; MacKenzie, Adrian; Alder, Rob; Langley, Joanne; Hickey, Marjorie; Cook, Amanda

    2013-10-01

    A competency-based approach to health human resources (HHR) planning is one that explicitly considers the spectrum of knowledge, skills and judgement (competencies) required for the health workforce based on the health needs of the relevant population in some specific circumstances. Such an approach is of particular benefit to planners challenged to make optimal use of limited HHR as it allows them to move beyond simply estimating numbers of certain professionals required and plan instead according to the unique mix of competencies available from the existing health workforce. This kind of flexibility is particularly valuable in contexts where healthcare providers are in short supply generally (e.g. in many developing countries) or temporarily due to a surge in need (e.g. a pandemic or other disease outbreak). A pilot application of this approach using the context of an influenza pandemic in one health district of Nova Scotia, Canada, is described, and key competency gaps identified. The approach is also being applied using other conditions in other Canadian jurisdictions and in Zambia.

  5. A bi-cistronic, reporter-encoding bovine viral diarrhea virus applied in a new, effective diagnostic test.

    PubMed

    Gebauer, Mandy; Behrens, Martina; König, Matthias; Behrens, Sven-Erik

    2014-07-01

    Infections with bovine viral diarrhea virus (BVDV) have a huge economic impact on cattle production and reproduction worldwide. A key factor for BVDV surveillance and eventual eradication is to efficiently detect infections and to monitor herd immunity. In this study, we generated a stable, bi-cistronic BVDV that encoded EGFP in addition to the viral proteins. Applying this recombinant virus, a new flow-cytometry-based virus neutralization test was established that enabled accurate and reliable detection of field-virus-infected and vaccinated animals. The test, which is simple and fast, is expected to support novel, effective screening procedures in eradication and vaccination programmes. PMID:24760759

  6. A bi-cistronic, reporter-encoding bovine viral diarrhea virus applied in a new, effective diagnostic test.

    PubMed

    Gebauer, Mandy; Behrens, Martina; König, Matthias; Behrens, Sven-Erik

    2014-07-01

    Infections with bovine viral diarrhea virus (BVDV) have a huge economic impact on cattle production and reproduction worldwide. A key factor for BVDV surveillance and eventual eradication is to efficiently detect infections and to monitor herd immunity. In this study, we generated a stable, bi-cistronic BVDV that encoded EGFP in addition to the viral proteins. Applying this recombinant virus, a new flow-cytometry-based virus neutralization test was established that enabled accurate and reliable detection of field-virus-infected and vaccinated animals. The test, which is simple and fast, is expected to support novel, effective screening procedures in eradication and vaccination programmes.

  7. Field test of infrared thermography applied to biogas controlling in landfill sites

    NASA Astrophysics Data System (ADS)

    Madruga, Francisco J.; Muñoz, Jaime M.; González, Daniel A.; Tejero, Juan I.; Cobo, Adolfo; Gil, José L.; Conde, Olga M.; López-Higuera, Jose M.

    2007-04-01

    The gases accumulated inside the landfill as result of the fermentation of Municipal Solid Waste (MSW) known as biogas, are taking into consideration all possible uses as direct transformation into electricity. The system for collecting, regulating and controlling the biogas must include all the necessary safety features where the biogas leakage presents a high impact. Infrared thermography can be use to detect gas leakages due to the differences in temperature between the gas and the immediate surroundings. This method is able to monitor a wide area of landfill sites, quickly. This technology will not be effective if the differences in temperature are not better than five degrees. This paper describes a field test conducted to study the limitations of the infrared thermography caused by weather conditions and the moment of day or/and season when the thermal images was captured. Pipelines, borders, cells, covers, slopes and leakage (hot spots) are studied and optimum conditions are defined.

  8. A Theoretical Investigation of Composite Overwrapped Pressure Vessel (COPV) Mechanics Applied to NASA Full Scale Tests

    NASA Technical Reports Server (NTRS)

    Greene, N.; Thesken, J. C.; Murthy, P. L. N.; Phoenix, S. L.; Palko, J.; Eldridge, J.; Sutter, J.; Saulsberry, R.; Beeson, H.

    2006-01-01

    A theoretical investigation of the factors controlling the stress rupture life of the National Aeronautics and Space Agency's (NASA) composite overwrapped pressure vessels (COPVs) continues. Kevlar(TradeMark) fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar(TradeMark) filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However, due to the presence of a load sharing liner, the manufacturing induced residual stresses and the complex mechanical response, the state of actual fiber stress in flight hardware and test articles is not clearly known. This paper is a companion to the experimental investigation reported in [1] and develops a theoretical framework necessary to design full-scale pathfinder experiments and accurately interpret the experimentally observed deformation and failure mechanisms leading up to static burst in COPVs. The fundamental mechanical response of COPVs is described using linear elasticity and thin shell theory and discussed in comparison to existing experimental observations. These comparisons reveal discrepancies between physical data and the current analytical results and suggest that the vessel's residual stress state and the spatial stress distribution as a function of pressure may be completely different from predictions based upon existing linear elastic analyses. The 3D elasticity of transversely isotropic spherical shells demonstrates that an overly compliant transverse stiffness relative to membrane stiffness can account for some of this by shifting a thin shell problem well into the realm of thick shell response. The use of calibration procedures are demonstrated as calibrated thin shell model results and finite element results are shown to be in good agreement with the experimental results. The successes reported here have lead to continuing work with full scale testing of larger NASA COPV

  9. A Theoretical Investigation of Composite Overwrapped Pressure Vessel (COPV) Mechanics Applied to NASA Full Scale Tests

    NASA Technical Reports Server (NTRS)

    Thesken, John C.; Murthy, Pappu L. N.; Phoenix, S. L.; Greene, N.; Palko, Joseph L.; Eldridge, Jeffrey; Sutter, James; Saulsberry, R.; Beeson, H.

    2009-01-01

    A theoretical investigation of the factors controlling the stress rupture life of the National Aeronautics and Space Administration's (NASA) composite overwrapped pressure vessels (COPVs) continues. Kevlar (DuPont) fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However due to the presence of a load sharing liner, the manufacturing induced residual stresses and the complex mechanical response, the state of actual fiber stress in flight hardware and test articles is not clearly known. This paper is a companion to a previously reported experimental investigation and develops a theoretical framework necessary to design full-scale pathfinder experiments and accurately interpret the experimentally observed deformation and failure mechanisms leading up to static burst in COPVs. The fundamental mechanical response of COPVs is described using linear elasticity and thin shell theory and discussed in comparison to existing experimental observations. These comparisons reveal discrepancies between physical data and the current analytical results and suggest that the vessel s residual stress state and the spatial stress distribution as a function of pressure may be completely different from predictions based upon existing linear elastic analyses. The 3D elasticity of transversely isotropic spherical shells demonstrates that an overly compliant transverse stiffness relative to membrane stiffness can account for some of this by shifting a thin shell problem well into the realm of thick shell response. The use of calibration procedures are demonstrated as calibrated thin shell model results and finite element results are shown to be in good agreement with the experimental results. The successes reported here have lead to continuing work with full scale testing of larger NASA COPV

  10. Advancing the vesosome, a multifunctional drug delivery platform, toward applied in vivo testing

    NASA Astrophysics Data System (ADS)

    Wong, Benjamin J.

    An optimal drug delivery vehicle should circulate long enough to reach the site of illness or disease, possess a large drug loading capacity, retain its contents over the course of treatment, and be able deliver its contents at a rate appropriate for maximum therapeutic benefit at the site of interest. The vesosome, a large lipid bilayer enclosing multiple, smaller liposomes, is our solution to addressing these needs. The external lipid bilayer offers a second barrier of protection for interior components and can also serve as the anchor for active targeting components. Furthermore, internal compartmentalization permits customization of separate environments for multiple therapeutics and release triggers. Previous work established the ability of the vesosome to retain its contents in vitro an order of magnitude longer than liposomes. To be viable in vivo, the vesosome must be functionalized for biocompatibility and tracking, and its synthetic procedure must be repeatable, reliable and result in a purified product. The vesosome was functionalized by introducing biocompatible polymers, such as poly(ethylene glycol) (PEG), and fluorescent dyes in their lipid-bound forms into the external membrane of the vesosome. The external vesosomal membrane is formed from large, flat lipid sheets in the interdigitated (L betaI) phase which, when heated, are used to encapsulate smaller drug-containing vesicles. Through X-Ray diffraction (XRD) and freeze-fracture transmission electron microscopy (FF-TEM), we established that the molar amounts of functionalized lipid required to label the vesosome for tracking and biocompatibility (˜5--7mol% total) did not prevent the formation of the interdigitated phase. Thus, functionalization of the external vesosome membrane can be achieved through functionalization of interdigitated sheets. For in vivo testing, functionalized vesosomes must be separated from unencapsulated vesicles and purification was performed using size exclusion

  11. Laboratory investigation and commercial test for rotors-assembled strand applied in smooth tube

    SciTech Connect

    Li, Feng-Xiang; Ding, Yu-Mei; Guan, Chang-Feng; Xie, Peng-Cheng; Yan, Hua; Yang, Wei-Min

    2008-10-15

    In the commercial test for smooth tube inserted with rotors-assembled strand comparing with non-inserted ones on condensers in electric power plant, using water as working fluid, the single-phase pressure drop and heat transfer were measured. It was found difficult to receive reliable and accurate enough data through commercial test. Meanwhile, the single-phase pressure drop and heat transfer in a rotors-assembled strand inserted tube were measured in laboratory, with the tube side Prandtl numbers varying from 5.67 to 5.80 and the tube side Reynolds numbers varying from 21,300 to 72,200. Before that, a validation experiment based on the same smooth tube was carried out to testify the experimental system and the data reduction method, in which fixed mounts were employed to eliminate entrance effects. The Prandtl numbers varied from 5.64 to 5.76 and the Reynolds numbers varied from 19,000 to 56,000 in the tube. The annular side Reynolds numbers remained nearly constant at the value of around 50,000 for all experiments, with the annular side Prandtl numbers varying from 8.02 to 8.22. The experimental results of smooth tube show that employment of fixed mounts leads to a visible bias of friction factor at relative low Reynolds numbers while it hardly affects the Nusselt numbers. On the other hand, experiment for the tube inserted with rotors-assembled strand show remarkable improvement for heat transfer with the Nusselt number increased by 9.764-11.87% and the overall heat transfer coefficient increased by 7.08-7.49% within the range of Reynolds number from about 21,300 to 55,500. Meanwhile, friction factor increases inevitably by 278.1-353.9% within the same range of Reynolds number. Based on through multivariant linear normal regression method, the Reynolds number and Prandtl number dependencies of the Nusselt number and friction factor were determined to be Nu = 0.0031Re{sup 0.9}Pr{sup 1.0849} and f = 0.993Re{sup -0.22}. (author)

  12. Phytotoxic activity of Ocimum tenuiflorum extracts on germination and seedling growth of different plant species.

    PubMed

    Islam, A K M Mominul; Kato-Noguchi, Hisashi

    2014-01-01

    Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae) plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), Italian ryegrass (Lolium multiflorum), barnyard grass (Echinochloa crus-galli), and timothy (Phleum pratense) at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL(-1) reduced significantly the total germination percent (GP), germination index (GI), germination energy (GE), speed of emergence (SE), seedling vigour index (SVI), and coefficient of the rate of germination (CRG) of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T 50) and mean germination time (MGT) were increased at the same or higher than this concentration. The increasing trend of T 50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL(-1). The I 50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL(-1). Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds. PMID:25032234

  13. Phytotoxic Activity of Ocimum tenuiflorum Extracts on Germination and Seedling Growth of Different Plant Species

    PubMed Central

    2014-01-01

    Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae) plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), Italian ryegrass (Lolium multiflorum), barnyard grass (Echinochloa crus-galli), and timothy (Phleum pratense) at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1 reduced significantly the total germination percent (GP), germination index (GI), germination energy (GE), speed of emergence (SE), seedling vigour index (SVI), and coefficient of the rate of germination (CRG) of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50) and mean germination time (MGT) were increased at the same or higher than this concentration. The increasing trend of T50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. The I50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds. PMID:25032234

  14. Essays in applied microeconomics: measuring the multilateral allocation of rent and dual tests of market power

    SciTech Connect

    Kerkvliet, J.

    1986-01-01

    The first essay develops a general econometric procedure for the join estimation of rents in a bilateral monopoly/oligopoly market for an intermediate good. This procedure is utilized to measure the rent-gathering success of firms involved in the extraction, transportation, and consumption of Wyoming coal. Statistical results indicate that railroads and coal producers capture 23% of potential rent, while taxing authorities and utilities capture 7 and 47%, respectively. Further statistical tests indicate that rents have shifted towards railroads since their deregulation in 1980 and that railroads and coal producers engage in price discrimination. The second essay estimates the extent to which regulated electric utilities are inefficient in the use of base-load fossil fuels. Utilities are assumed to be shadow profit maximizers acting as if they face shadow prices which may diverge from observed prices because of monopoly power in output markets, monopsony power in input markets, or distortions induced by fuel-adjustment-clause rate making. Supply, demand, and actual profit equations are derived from a behavioral profit function, and the model is estimated for a sample of utilities using Wyoming and Montana coal. Results indicate that this group of utilities uses fuel inefficiently.

  15. Testing the cleaning effectiveness of new ecological aqueous dispersions applied on old icons

    NASA Astrophysics Data System (ADS)

    Vasilache, Viorica; Sandu, Irina Crina Anca; Pruteanu, Silvea; Caldeira, Ana Teresa; Simionescu, Atena Elena; Sandu, Ion

    2016-03-01

    Adherent deposits are very aggressive towards ancient heritage paintings since they affect the varnish and the painting's layers, sometimes reaching the preparative layers. The biggest problem to the restorer is their removal without affecting the patina, the transparent varnish (well preserved) and fine colour glazes made during painting. Therefore, their removal requires preliminary cleaning tests that allow the optimization of the cleaning system composition that is going to be used. The study was focused on organic natural systems, as colourless supernatants, some of them used during ages, but insufficiently studied. The paper presents an evaluation of the effectiveness of cleaning varnished icons of the nineteenth century, with complex conservation cases using supernatants derived from aqueous dispersions extracted from vegetables and dry indigenous herbal infusions. Best results, after six consecutive cleaning steps, on tempera old icon was obtained for a mixture made of mature white onion juice + extract of Soapwort flowers + corn silk tea + acacia tea. As a best result after just one cleaning step was obtained for a quaternary mixture composed from mature white onion juice + mature carrot juice + corn silk tea + aqueous extract of Soapwort flowers.

  16. Expansion of Perturbation Theory Applied to Shim Rotation Automation of the Advanced Test Reactor

    NASA Astrophysics Data System (ADS)

    Peterson, Joshua Loren

    In 2007, the Department of Energy (DOE) declared the Advanced Test Reactor (ATR) a National Scientific User Facility (NSUF). This declaration expanded the focus of the ATR to include diversified classes of academic and industrial experiments. An essential part of the new suite of more accurate and flexible codes being deployed to support the NSUF is their ability to predict reactor behavior at startup, particularly the position of the outer shim control cylinders (OSCC). The current method used for calculating the OSCC positions during a cycle startup utilizes a heuristic trial and error approach that is impractical with the computationally intensive reactor physics tools, such as NEWT. It is therefore desirable that shim rotation prediction for startup be automated. Shim rotation prediction with perturbation theory was chosen to be investigated as one method for use with startup calculation automation. A modified form of first order perturbation theory, called phase space interpolated perturbation theory, was developed to more accurately model shim rotation prediction. Shim rotation prediction is just one application for this new modified form of perturbation theory. Phase space interpolated perturbation theory can be used on any application where the range of change to the system is known a priori, but the magnitude of change is not known. A cubic regression method was also developed to automate shim rotation prediction by using only forward solutions to the transport equation.

  17. Increasing the antioxidant activity, total phenolic and flavonoid contents by optimizing the germination conditions of amaranth seeds.

    PubMed

    Perales-Sánchez, Janitzio X K; Reyes-Moreno, Cuauhtémoc; Gómez-Favela, Mario A; Milán-Carrillo, Jorge; Cuevas-Rodríguez, Edith O; Valdez-Ortiz, Angel; Gutiérrez-Dorado, Roberto

    2014-09-01

    The aim of this study was to optimize the germination conditions of amaranth seeds that would maximize the antioxidant activity (AoxA), total phenolic (TPC), and flavonoid (TFC) contents. To optimize the germination bioprocess, response surface methodology was applied over three response variables (AoxA, TPC, TFC). A central composite rotable experimental design with two factors [germination temperature (GT), 20-45 ºC; germination time (Gt), 14-120 h] in five levels was used; 13 treatments were generated. The amaranth seeds were soaked in distilled water (25 °C/6 h) before germination. The sprouts from each treatment were dried (50 °C/8 h), cooled, and ground to obtain germinated amaranth flours (GAF). The best combination of germination bioprocess variables for producing optimized GAF with the highest AoxA [21.56 mmol trolox equivalent (TE)/100 g sample, dw], TPC [247.63 mg gallic acid equivalent (GAE)/100 g sample, dw], and TFC [81.39 mg catechin equivalent (CAE)/100 g sample, dw] was GT = 30 ºC/Gt = 78 h. The germination bioprocess increased AoxA, TPC, and TFC in 300-470, 829, and 213%, respectively. The germination is an effective strategy to increase the TPC and TFC of amaranth seeds for enhancing functionality with improved antioxidant activity.

  18. Do seed mass and family affect germination and juvenile performance in Knautia arvensis? A study using failure-time methods

    NASA Astrophysics Data System (ADS)

    Vange, Vibekke; Heuch, Ivar; Vandvik, Vigdis

    2004-05-01

    Germination and seedling establishment are vulnerable stages in the plant life cycle. We investigated how seed mass and family (progeny origin) affect germination and juvenile performance in the grassland herb Knautia arvensis. Seeds were produced by cross-pollination by hand. The fate of 15 individually weighed seeds from each of 15 plants was followed during a 3-month growth chamber experiment. Progeny origin affected germination, both through seed mass and as an independent factor. Two groups of progenies could be distinguished by having rapid or delayed germination. The two groups had similar mean seed masses, but a positive relationship between seed mass and germination rate could be established only among the rapidly germinating progenies. These biologically relevant patterns were revealed because timing of germination was taken into account in the analyses, not only frequencies. Time-to-event data were analysed with failure-time methods, which gave more stable estimates for the relation between germination and seed mass than the commonly applied logistic regression. Progeny origin and seed mass exerted less impact on later characters like juvenile survival, juvenile biomass, and rosette number. These characters were not affected by the timing of germination under the competition-free study conditions. The decrease in the effect of progeny origin from the seed and germination to the juvenile stages suggests that parental effects other than those contributing to the offspring genotype strongly influenced the offspring phenotype at the earliest life stages. Further, the division of progeny germination patterns into two fairly distinct groups indicates that there was a genetic basis for the variation in stratification requirements among parental plants. Field studies are needed to elucidate effects of different timing of germination in the seasonal grasslands that K. arvensis inhabits.

  19. Effects of water potential on spore germination and viability of Fusarium species.

    PubMed

    Palmero Llamas, D; de Cara Gonzalez, M; Iglesias Gonzalez, C; Ruíz Lopez, G; Tello Marquina, J C

    2008-11-01

    Germination of macroconidia and/or microconidia of 24 strains of Fusarium solani, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. sambucinum, F. oxysporum and F. proliferatum isolated from fluvial channels and sea beds of the south-eastern coast of Spain, and three control strains (F. oxysporum isolated from affected cultures) was studied in distilled water in response to a range of water potentials adjusted with NaCl. (0, -13.79, -41.79, -70.37, -99.56 and -144.54 bars). The viability (UFC/ml) of suspensions was also tested in three time periods (0, 24 and 48 h). Conidia always germinated in distilled water. The pattern of conidial germination observed of F. verticilloides, F. oxysporum, F. proliferatum, F. chlamydosporum and F. culmorum was similar. A great diminution of spore germination was found in -13.79 bars solutions. Spore germination percentage for F. solani isolates was maximal at 48 h and -13.79 bars with 21.33% spore germination, 16% higher than germination in distilled water. F. equiseti shows the maximum germination percentage in -144.54 bars solution in 24 h time with 12.36% germination. This results did not agree with those obtained in the viability test were maximum germination was found in distilled water. The viability analysis showed the great capacity of F. verticilloides strains to form viable colonies, even in such extreme conditions as -144.54 bars after 24 h F. proliferatum colony formation was prevented in the range of -70.37 bars. These results show the clear affectation of water potential to conidia germination of Fusaria. The ability of certain species of Fusarium to develop a saprophytic life in the salt water of the Mediterranean Sea could be certain. Successful germination, even under high salty media conditions, suggests that Fusarium spp. could have a competitive advantage over other soil fungi in crops irrigated with saline water. In the specific case of F. solani, water potential of -13.79 bars affected

  20. Combined cycle testing experience applied to on-line performance monitoring

    SciTech Connect

    DesJardins, R.R.; Chung-Sherg Liu

    1995-12-31

    Combined cycle plants account for an increasing share of new power projects in progress throughout the world today. The financial performance of many of these projects depends on the thermal performance of the plant. Further, market competition puts added pressure on these plants to operate at high levels of availability and thermal efficiency. On-line performance monitoring is one technique that has proven successful in achieving and maintaining goals for optimum performance. The combined cycle plant presents a special challenge to the performance engineer seeking to trend and assess plant condition. Seasonal and daily fluctuations in ambient conditions cause the plant to operate at varying levels of plant efficiency and capacity. Therefore, measured performance must be corrected to standard conditions before day-to-day comparisons can be made. An on-line monitoring system using a proven correction methodology has been installed at the 522-MWe combined-cycle Stony Brook Energy Center in Ludlow, Massachusetts. The correction methodology was developed and employed at General Physics Corporation for combined cycle plant acceptance testing. The on-line system is PC-based and operates on the plant`s local area network. Historical performance information and real-time graphical displays are available to all levels of plant personnel, including control room operators, shift supervisors, plant engineers, and managers. The on-line system, installed in 1994, continuously monitors five (5) General Electric Frame 7 gas turbines, three (3) heat recovery steam generators, and a single steam turbine. Equipment and overall plant performance is correct to 20 {degrees}F and 90 {degrees}F Standard Days. The system provides both short term and long term equipment condition trending, while also assisting with detection of misfiring combustion cans.

  1. Energy Smart Schools--Applied Research, Field Testing, and Technology Integration

    SciTech Connect

    Nebiat Solomon; Robin Vieira; William L. Manz; Abby Vogen; Claudia Orlando; Kimberlie A. Schryer

    2004-12-01

    The National Association of State Energy Officials (NASEO) in conjunction with the California Energy Commission, the Energy Center of Wisconsin, the Florida Solar Energy Center, the New York State Energy Research and Development Authority, and the Ohio Department of Development's Office of Energy Efficiency conducted a four-year, cost-share project with the U.S. Department of Energy (USDOE), Office of Energy Efficiency and Renewable Energy to focus on energy efficiency and high-performance technologies in our nation's schools. NASEO was the program lead for the MOU-State Schools Working group, established in conjunction with the USDOE Memorandum of Understanding process for collaboration among state and federal energy research and demonstration offices and organizations. The MOU-State Schools Working Group included State Energy Offices and other state energy research organizations from all regions of the country. Through surveys and analyses, the Working Group determined the school-related energy priorities of the states and established a set of tasks to be accomplished, including the installation and evaluation of microturbines, advanced daylighting research, testing of schools and classrooms, and integrated school building technologies. The Energy Smart Schools project resulted in the adoption of advanced energy efficiency technologies in both the renovation of existing schools and building of new ones; the education of school administrators, architects, engineers, and manufacturers nationwide about the energy-saving, economic, and environmental benefits of energy efficiency technologies; and improved the learning environment for the nation's students through use of better temperature controls, improvements in air quality, and increased daylighting in classrooms. It also provided an opportunity for states to share and replicate successful projects to increase their energy efficiency while at the same time driving down their energy costs.

  2. Intrathecally applied flurbiprofen produces an endocannabinoid-dependent antinociception in the rat formalin test.

    PubMed

    Ates, Mehmet; Hamza, May; Seidel, Kay; Kotalla, Carolin E; Ledent, Catherine; Gühring, Hans

    2003-02-01

    It is generally accepted that the phospholipase-A2-cyclooxygenase-prostanoids-cascade mediates spinal sensitization and hyperalgesia. However, some observations are not in line with this hypothesis. The aim of the present work was to investigate whether different components of this cascade exhibit nociceptive or antinociceptive effects in the rat formalin test. Intrathecal (i.th.) injection of prostaglandin E2 (PGE2) induced a dose-dependent antinociceptive effect on the formalin-induced nociception. Furthermore, thimerosal, which inhibits the reacylation of arachidonic acid thereby enhancing arachidonic acid levels, had an antinociceptive effect rather than the expected pronociceptive effect when given i.th. While the phospholipase A2 inhibitor methyl arachidonyl fluorophosphonate (MAFP; i.th.) had a significant antinociceptive effect, its analogue palmitoyl trifluoromethyl ketone (PTFMK; i.th.) had no significant effect on the formalin-induced nociception. However, MAFP, but not PTFMK, showed a cannabinoid CB1 agonistic effect as shown by the inhibition of electrically evoked contractions of the vas deferens isolated from CB1 wild-type mice but not of that from CB1 knockout mice. The antinociceptive effect of MAFP was completely reversed by the CB1 receptor antagonist AM-251 (i.th.), thus attributing such effect to its CB1 agonistic effect. Moreover, the antinociceptive effect of the cyclooxygenase inhibitor, flurbiprofen (i.th.) was reversed by the co-administration of AM-251, but not by PGE2. Finally. the combination of phenylmethylsulfonyl fluoride (PMSF; intraperitoneal), which inhibits the degradation of anandamide through the inhibition of fatty acid amidohydrolase, with thimerosal (i.th.) produced a profound CB1-dependent antinociception. The present results show that endocannabinoids play a major role in mediating flurbiprofen-induced antinociception at the spinal level.

  3. In vitro germination characteristics of maize pollen to detect biological activity of environmental pollutants

    SciTech Connect

    Pfahler, P.L.

    1981-01-01

    In vitro pollen germination in maize was evaluated as a method of assessing the mutagenic and physiological effects of environmental pollutants on higher organisms. The extent of mutations was effectively determined by testing sporophytes homozygous for the mutated allele. Physiological effects were effectively determined when chemical agents were added directly into the in vitro medium. Exposure of pollen grains during in vitro germination to ultraviolet radiation in the range 280-320 nm produced little or no change in the germination or rupture percentage but a sharp decrease in pollen tube growth after 1 hr.

  4. Intranasal Osteopontin for Rodent Germinal Matrix Hemorrhage.

    PubMed

    Malaguit, Jay; Casel, Darlene; Dixon, Brandon; Doycheva, Desislava; Tang, Jiping; Zhang, John H; Lekic, Tim

    2016-01-01

    Germinal matrix hemorrhage (GMH) is the most common and devastating neurological problem of premature infants. Current treatment is largely ineffective and GMH has been nonpreventable. Osteopontin (OPN) is an endogenous protein that has been shown to be neuroprotective, however, it has not been tested in GMH. P7 neonatal rats were subjected to stereotactic ganglionic eminence collagenase infusion. Groups were as follows: (1) sham, (2) GMH + vehicle, (3) GMH + intranasal OPN. Seventy-two hours later, the animals were evaluated using righting reflex, blood-brain barrier (BBB) permeability by Evans blue dye leakage, brain water content, and hemoglobin assay. Intranasal OPN improved outcomes after GMH by attenuation of brain swelling, BBB function, re-bleeding, and neurological outcomes. OPN may play an important role in enhancing neuroprotective brain signaling following GMH. These observed effects may offer novel possibilities for therapy in this patient population. PMID:26463952

  5. Identification of embryo proteins associated with seed germination and seedling establishment in germinating rice seeds.

    PubMed

    Liu, Shu-Jun; Xu, Heng-Heng; Wang, Wei-Qing; Li, Ni; Wang, Wei-Ping; Lu, Zhuang; Møller, Ian Max; Song, Song-Quan

    2016-06-01

    Seed germination is a critical phase in the plant life cycle, but the mechanism of seed germination is still poorly understood. In the present study, rice (Oryza sativa L. cv. Peiai 64S) seeds were sampled individually when they reached different germination stages, quiescent, germinated sensu stricto, germinated completely and seedling, and were used to study the changes in the embryo proteome. A total of 88 protein spots showed a significant change in abundance during germination in water, and the results showed an activation of metabolic processes. Cell division, cell wall synthesis, and secondary metabolism were activated at late seed germination and during preparation for subsequent seedling establishment. Cycloheximide (CHX) at 70μM inhibited seedling establishment without an apparent negative effect on seed germination, while CHX at 500μM completely blocked seed germination. We used this observation to identify the potentially important proteins involved in seed germination (coleoptile protrusion) and seedling establishment (coleoptile and radicle protrusion). Twenty-six protein spots, mainly associated with sugar/polysaccharide metabolism and energy production, showed a significant difference in abundance during seed germination. Forty-nine protein spots, mainly involved in cell wall biosynthesis, proteolysis as well as cell defense and rescue, were required for seedling establishment. The results help improve our understanding of the key events (proteins) involved in germination and seedling development.

  6. Identification of embryo proteins associated with seed germination and seedling establishment in germinating rice seeds.

    PubMed

    Liu, Shu-Jun; Xu, Heng-Heng; Wang, Wei-Qing; Li, Ni; Wang, Wei-Ping; Lu, Zhuang; Møller, Ian Max; Song, Song-Quan

    2016-06-01

    Seed germination is a critical phase in the plant life cycle, but the mechanism of seed germination is still poorly understood. In the present study, rice (Oryza sativa L. cv. Peiai 64S) seeds were sampled individually when they reached different germination stages, quiescent, germinated sensu stricto, germinated completely and seedling, and were used to study the changes in the embryo proteome. A total of 88 protein spots showed a significant change in abundance during germination in water, and the results showed an activation of metabolic processes. Cell division, cell wall synthesis, and secondary metabolism were activated at late seed germination and during preparation for subsequent seedling establishment. Cycloheximide (CHX) at 70μM inhibited seedling establishment without an apparent negative effect on seed germination, while CHX at 500μM completely blocked seed germination. We used this observation to identify the potentially important proteins involved in seed germination (coleoptile protrusion) and seedling establishment (coleoptile and radicle protrusion). Twenty-six protein spots, mainly associated with sugar/polysaccharide metabolism and energy production, showed a significant difference in abundance during seed germination. Forty-nine protein spots, mainly involved in cell wall biosynthesis, proteolysis as well as cell defense and rescue, were required for seedling establishment. The results help improve our understanding of the key events (proteins) involved in germination and seedling development. PMID:27085178

  7. Applying the theory of planned behaviour to explain HIV testing in antenatal settings in Addis Ababa - a cohort study

    PubMed Central

    2011-01-01

    Background To facilitate access to the prevention of mother-to-child HIV transmission (PMTCT) services, HIV counselling and testing are offered routinely in antenatal care settings. Focusing a cohort of pregnant women attending public and private antenatal care facilities, this study applied an extended version of the Theory of Planned Behaviour (TPB) to explain intended- and actual HIV testing. Methods A sequential exploratory mixed methods study was conducted in Addis Ababa in 2009. The study involved first time antenatal attendees from public- and private health care facilities. Three Focus Group Discussions were conducted to inform the TPB questionnaire. A total of 3033 women completed the baseline TPB interviews, including attitudes, subjective norms, perceived behavioural control and intention with respect to HIV testing, whereas 2928 completed actual HIV testing at follow up. Data were analysed using descriptive statistics, Chi-square tests, Fisher's Exact tests, Internal consistency reliability, Pearson's correlation, Linear regression, Logistic regression and using Epidemiological indices. P-values < 0.05 was considered significant and 95% Confidence Interval (CI) was used for the odds ratio. Results The TPB explained 9.2% and 16.4% of the variance in intention among public- and private health facility attendees. Intention and perceived barriers explained 2.4% and external variables explained 7% of the total variance in HIV testing. Positive and negative predictive values of intention were 96% and 6% respectively. Across both groups, subjective norm explained a substantial amount of variance in intention, followed by attitudes. Women intended to test for HIV if they perceived social support and anticipated positive consequences following test performance. Type of counselling did not modify the link between intended and actual HIV testing. Conclusion The TPB explained substantial amount of variance in intention to test but was less sufficient in explaining

  8. Endoreduplication in the germinating embryo and young seedling is related to the type of seedling establishment but is not coupled with superoxide radical accumulation.

    PubMed

    Rewers, Monika; Sliwinska, Elwira

    2014-08-01

    During germination, the embryo axis elongates and the radicle emerges through the surrounding structures of the seed. However, this elongation is not even along the axis, and it has been suggested that the region responsible for radicle protrusion is related to the type of subsequent seedling establishment. Eleven epigeal- and five hypogeal-type species were selected to study endoreduplication, a process coupled with cell elongation, in the radicle, hypocotyl-radicle transition zone, hypocotyl, and cotyledons of dry and germinating seeds, and in seedlings after radicle protrusion. Flow cytometry was used to establish the proportions of nuclei with different DNA contents, the mean C-value, and the (Σ>2C)/2C ratio. Additionally, a nitroblue tetrazolium chloride test was applied to the embryos/seedlings in the dry state and during and after germination to localize superoxide radical (O2(•-)) accumulation, which has been suggested to play a role in cell elongation. Endoreduplication intensity varied in different species, in the embryo/seedling regions, and with the type of seedling establishment. In most of the cases, it was highest in the transition zone of epigeal species and in the hypocotyl in hypogeal species. O2(•-) was invariably produced during germination in the radicle, and additionally in the transition zone at the time of radicle protrusion; thus, it was not coupled with endoreduplication, and most probably played a role in defence against biotic and abiotic environmental stresses. These results provide information to aid in the selection of the most suitable plant material for molecular research on germination and for monitoring seed priming.

  9. Allelopathic effects of weeds extracts against seed germination of some plants.

    PubMed

    Kadioglu, Izzet; Yanar, Yusuf; Asav, Unal

    2005-04-01

    This study investigated the allelopathic effects of various weeds extracts on seed germination of 11 crop species. Most of the weed extracts tested had inhibitory effects on seed germination of common bean, tomato, pepper, squash, onion, barley, wheat, and corn at different application rates as compared with the 10% acetone control. Chickpea seed germination was inhibited by extracts of Solanum nigrum L., Chenopodium album L., and Matricaria chamomilla L. (10%, 20% and 22.5%, respectively) at the end of 21 day incubation period. However, Glycyrrhiza glabra L., Sorghum halepense (L.) Pers., and Reseda lutea L. extracts stimulated chickpea seed germination at the rates of 95%, 94%, and 93%, respectively, compared to control. It was concluded that some of the weed extracts tested in this study could be used as inhibitor while others could be used as stimulator for the crops.

  10. Post-burning regeneration of the Chaco seasonally dry forest: germination response of dominant species to experimental heat shock.

    PubMed

    Jaureguiberry, Pedro; Díaz, Sandra

    2015-03-01

    Plant species of the Chaco seasonally dry forest of central Argentina have presumably been under a low evolutionary pressure to develop specialized fire-response traits, such as heat-stimulated germination. Nevertheless, other historical factors such as seasonal drought and/or endozoochorus dispersal could have led some species to develop heat-tolerant seeds. Therefore, heat-tolerant germination should be more common than heat-stimulated or heat-sensitive germination. To test this, we exposed seeds of 26 dominant species from the Chaco region to a broad range of experimental heat treatments and incubated them for 30 days at 25 °C and 12 h photoperiod. We then scored the percent germination and classified them as heat-stimulated, heat-tolerant or heat-sensitive based on their germination following heat treatments relative to control. Seventeen species showed heat-tolerant germination, including all native graminoids. Seven species showed heat-stimulated germination, under the less-intense heat treatments. Only two species showed heat-sensitive germination. Endozoochory had no influence on germination responses. We suggest that, unlike Mediterranean-climate ecosystems, fire was not a major evolutionary force in the development of Chaco forests, and our results provide greater understanding of the potential response of Chaco plant communities in the face of increasingly frequent fires.

  11. Priming and temperature limits for germination of dispersal units of Urochloa brizantha (Stapf) Webster cv. basilisk.

    PubMed

    Nakao, E A; Cardoso, V J M

    2015-01-01

    The objective of this study was to evaluate the effect of priming treatments on the upper and lower thermal limits for germination of Urochloa brizantha cv. basilisk, and testing the hypothesis that pré-imbibition affect thermal parameters of the germination. Pre-imbibed seeds both in distilled water (0 MPa) and PEG 6000 solution (-0.5 MPa) were put to germinate in different temperatures. It is suggested that U. brizantha seeds have low response to priming when they were placed to germinate in medium where water is not limiting. The response of U. brizantha seeds to priming is dependent on the temperature and water potential conditions at which the seeds are pre-imbibed, as well as on the germination temperature. The optimum temperature for germination of U. brizantha shift toward warmer temperatures in primed seeds. Priming effect was more pronounced at temperatures closer to the upper and lower limit for germination, but probably that response cannot be accounted for changes in the thermal time constant (θT(g)) and ceiling temperature (Tc(g)). Otherwise, a decrease in the base temperature (Tb) was observed in primed seeds, suggesting that the Tb distribution in U. brizantha seeds is influenced by priming.

  12. Effect of phytohormones on seed germination and seedling growth of Coriandrum sativum L.

    PubMed

    Kumar, Mahender; Agnihotri, R K; Vamil, R; Sharma, R

    2014-04-01

    Coriander commonly known as Dhania or Chinese parsley is generally grown for its use in soups, salads, dressing vegetables, seasoning and chutney. Effect of two phytohormones viz. GA3 and 2,4-D on seed germination, seedling growth and various physiological and biochemical parameters were studied. The hormones were applied individually in different concentrations (10, 50 and 100 μM concentrations). Both the hormones enhanced the germination percentage, seedling growth (root and shoot length), leaf area, chlorophyll and carotenoid content. The application of these hormones also decreased the germination time. Maximum germination, shoot length, leaf area and carotenoid content was observed in 100 μm concentration of GA3. Root length, chl. a and chl. b was maximum in 50 μM of 2,4-D and 100 μm GA3, respectively. The application of two hormones exhibited a marked increase on all the parameters studied as compared to the control.

  13. Effect of phytohormones on seed germination and seedling growth of Coriandrum sativum L.

    PubMed

    Kumar, Mahender; Agnihotri, R K; Vamil, R; Sharma, R

    2014-04-01

    Coriander commonly known as Dhania or Chinese parsley is generally grown for its use in soups, salads, dressing vegetables, seasoning and chutney. Effect of two phytohormones viz. GA3 and 2,4-D on seed germination, seedling growth and various physiological and biochemical parameters were studied. The hormones were applied individually in different concentrations (10, 50 and 100 μM concentrations). Both the hormones enhanced the germination percentage, seedling growth (root and shoot length), leaf area, chlorophyll and carotenoid content. The application of these hormones also decreased the germination time. Maximum germination, shoot length, leaf area and carotenoid content was observed in 100 μm concentration of GA3. Root length, chl. a and chl. b was maximum in 50 μM of 2,4-D and 100 μm GA3, respectively. The application of two hormones exhibited a marked increase on all the parameters studied as compared to the control. PMID:25911855

  14. Hoarding decisions by Edward's long-tailed rats (Leopoldamys edwardsi) and South China field mice (Apodemus draco): the responses to seed size and germination schedule in acorns.

    PubMed

    Chang, Gang; Xiao, Zhishu; Zhang, Zhibin

    2009-09-01

    Co-varying traits in acorns such as seed size and germination schedule are important to influence the behavioural decisions of hoarding rodents. Using acorn pairs from cork oak (Quercus variabilis) (large size and short germination schedules) serrate oak (Q. serrata) (small size and short germination schedule) and qinggang (Cyclobalanopsis glauca) (small size and long germination schedule) with contrasting seed size and germination schedule, we conducted a series of experiments to investigate hoarding preferences in response to seed size and germination schedule by Edward's long-tailed rats (Leopoldamys edwardsi) and South China field mice (Apodemus draco) in semi-natural enclosures. We found that the seed size hypothesis was consistently supported: both rodent species ate more small acorns but hoarded more large ones regardless of germination schedules. However, the germination schedule hypothesis was also supported when similar sized acorns were simultaneously provided, e.g. Q. serrata versus C. glauca or germinating versus non-germinating Q. variabilis. Our results, contrary to the studies from North America, indicate that seed size is more important than germination schedules in determining whether the tested animals eat or hoard a given seed.

  15. Levels of germination proteins in Bacillus subtilis dormant, superdormant, and germinating spores.

    PubMed

    Chen, Yan; Ray, W Keith; Helm, Richard F; Melville, Stephen B; Popham, David L

    2014-01-01

    Bacterial endospores exhibit extreme resistance to most conditions that rapidly kill other life forms, remaining viable in this dormant state for centuries or longer. While the majority of Bacillus subtilis dormant spores germinate rapidly in response to nutrient germinants, a small subpopulation termed superdormant spores are resistant to germination, potentially evading antibiotic and/or decontamination strategies. In an effort to better understand the underlying mechanisms of superdormancy, membrane-associated proteins were isolated from populations of B. subtilis dormant, superdormant, and germinated spores, and the relative abundance of 11 germination-related proteins was determined using multiple-reaction-monitoring liquid chromatography-mass spectrometry assays. GerAC, GerKC, and GerD were significantly less abundant in the membrane fractions obtained from superdormant spores than those derived from dormant spores. The amounts of YpeB, GerD, PrkC, GerAC, and GerKC recovered in membrane fractions decreased significantly during germination. Lipoproteins, as a protein class, decreased during spore germination, while YpeB appeared to be specifically degraded. Some protein abundance differences between membrane fractions of dormant and superdormant spores resemble protein changes that take place during germination, suggesting that the superdormant spore isolation procedure may have resulted in early, non-committal germination-associated changes. In addition to low levels of germinant receptor proteins, a deficiency in the GerD lipoprotein may contribute to heterogeneity of spore germination rates. Understanding the reasons for superdormancy may allow for better spore decontamination procedures.

  16. A Study of Germination Inhibition in Fruits.

    ERIC Educational Resources Information Center

    Gill, John

    1982-01-01

    Describes a method for the extraction and bioassay of natural germination inhibitors, requiring only inexpensive equipment and minimal experimental skill. The method has been used to demonstrate qualitative/quantitative differences in germination inhibitor levels in a variety of different fruits or in different tissues within a single fruit.…

  17. Germinated wheat: Phytochemical composition and mixing characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Germinated grain recently attracts interest due to its beneficial effect on human health. In this research, whole wheat flour samples obtained after three days and five days of germination were analyzed for biochemical components, mixing quality, and effects on human breast cancer cells. Germinati...

  18. A methodology for community-level hypothesis testing applied to detect trends in phytoplankton and fish communities in Irish waters

    NASA Astrophysics Data System (ADS)

    Lynam, Christopher P.; Cusack, Caroline; Stokes, David

    2010-04-01

    Many simple (univariate, bivariate) and complex (multivariate) statistical techniques are used to investigate trends in biological communities and to test hypotheses about potential relationships between ecosystem components. However, the simple methods that are commonly used (regression and correlation) are prone to Type I error (rejecting a true null hypothesis) when applied repeatedly. Although multivariate methods are preferable for community analysis, their computations are mathematically demanding and the interpretation of their outputs can be challenging. We present simple community analysis (SCA), an intuitive methodology with which to test for trend and correlation at the community-level. We demonstrate SCA using fish survey and phytoplankton count data: the non-parametric test statistic, Kendall's tau, is used to determine the strength of trends in abundance in 65 species of fish sampled during the Irish groundfish survey (maximal length of sampling periods were 1999-2007 in ICES division VIIg and 2002-2007 in divisions VIa, VIIb and VIIj, however catches of numerous species were not recorded prior to 2003) and in 77 genera of phytoplankton sampled at Irish aquaculture sites (1991-2002). The sample distribution of the test statistic (tau is used here, but other measures may be used) is compared to the expected distribution using distributional tests (Kolmogorov-Smirnov) to evaluate the significance of community-level trends. The phytoplankton community has been increasing in abundance on Irish western and southwestern coasts (Kolmogorov-Smirnov test D > 0.5, p < 0.001). Similarly, and in agreement with previously published long-term studies, Lusitanian fish have been increasing on the shelf to the north and west of Ireland ( D ≥ 0.35, p < 0.001), while the boreal community has been declining to the south (southeast, D = 0.47, p < 0.001; southwest, D = 0.32, p = 0.03). Although SCA cannot identify causality, the trends in fish communities are as expected

  19. Increase in Testing Efficiency through the Development of an IT-Based Adaptive Testing Tool for Competency Measurement Applied to a Health Worker Training Test Case

    ERIC Educational Resources Information Center

    Kleinhans, Janne; Schumann, Matthias

    2015-01-01

    In the context of education and training, competency measurement (CM) is a central challenge in competency management. For complex CMs, a compromise must be addressed between the time available and the number of dimensions to be measured or the quality of the measurements. Increasing the efficiency of existing tests for CMs therefore poses a key…

  20. Effect of seed stimulation on germination and sugar beet yield

    NASA Astrophysics Data System (ADS)

    Prośba-Białczyk, U.; Szajsner, H.; Grzyś, E.; Demczuk, A.; Sacała, E.; Bąk, K.

    2013-03-01

    Germination and sugar beet yield after seed stimulation were investigated. The seeds came from the energ'hill technology and were subject to laser irradiation. The experiments were conducted in the laboratory and field conditions. Lengthening of germinal roots and hypocotyls was observed. A positive effect of the stimulation on the morphological features was observed for the Eh seeds and laser irradiation applied in a three-fold dose. The energ'hill seeds exhibited a significantly higher content of carotenoids in seedlings and an increase in the content of chlorophylls. Laser light irradiation favourably modified the ratio of chlorophyll a to b. The leaves and roots of plants developed from the energ'hill and irradiated seeds were characterized by higher dry matter content thanin non-stimulated seeds. Seed stimulation had a positive influence on yielding and the saccharose content.

  1. [Metabolic control of seed germination].

    PubMed

    Catusse, Julie; Strub, Jean-Marc; Job, Claudette; Van Dorsselaer, Alain; Job, Dominique

    2008-01-01

    We have used proteomics to better characterize germination and early seedling vigor in sugarbeet. Our strategy includes (1) construction of proteome reference maps for dry and germinating seeds of a high-vigor reference seed lot; (2) investigation of the specific tissue accumulation of proteins (root, cotyledon, perisperm); (3) investigation of changes in protein expression profiles detected in the reference seed lot subjected to different vigor-modifying treatments, e.g. aging and/or priming. More than 1 000 sugarbeet seed proteins have been identified by LC/MS-MS mass spectrometry (albumins, globulins and glutelins have been analyzed separately). Due to the conservation of protein sequences and the quality of MS sequencing (more than 10 000 peptide sequences have been obtained), the success rate of protein identification was on the average of 80%. This is to our knowledge the best detailed proteome analysis ever carried out in seeds. The data allowed us to build a detailed metabolic chart of the sugarbeet seed, generating new insights into the molecular mechanisms determining the development of a new seedling. Also, the proteome of a seed-storage tissue as the perisperm is described for the first time.

  2. Genotyping of endosperms to determine seed dormancy genes regulating germination through embryonic, endospermic, or maternal tissues in rice.

    PubMed

    Gu, Xing-You; Zhang, Jinfeng; Ye, Heng; Zhang, Lihua; Feng, Jiuhuan

    2014-12-04

    Seed dormancy is imposed by one or more of the embryo, endosperm, and maternal tissues that belong to two generations and represent two ploidy levels. Many quantitative trait loci (QTL) have been identified for seed dormancy as measured by gross effects on reduced germination rate or delayed germination in crop or model plants. This research developed an endosperm genotype-based genetic approach to determine specific tissues through which a mapped QTL regulates germination using rice as a model. This approach involves testing germination velocity for partially after-ripened seeds harvested from single plants heterozygous for a tested QTL and genotyping endosperms from individual germinated and nongerminated seeds with a codominant DNA marker located on the QTL peak region. Information collected about the QTL includes genotypic frequencies in germinated and/or nongerminated subpopulations; allelic frequency distributions during a germination period; endosperm or embryo genotypic differences in germination velocity; and genotypic frequencies for gametes involved in the double fertilization to form the sampled seeds. Using this approach, the seed dormancy loci SD12, SD1-2, and SD7-1 were determined to regulate germination through the embryo, endosperm, and maternal tissues, respectively; SD12 and SD1-2 acted additively on germination velocity in the offspring tissues; and SD12 also was associated with the preferential fertilization of male gametes in rice. This new genetic approach can be used to characterize mapped genes/QTL for tissue-specific functions in endospermic seeds and for marker-assisted selection of QTL alleles before or immediately after germination in crop breeding.

  3. Genotyping of Endosperms to Determine Seed Dormancy Genes Regulating Germination Through Embryonic, Endospermic, or Maternal Tissues in Rice

    PubMed Central

    Gu, Xing-You; Zhang, Jinfeng; Ye, Heng; Zhang, Lihua; Feng, Jiuhuan

    2014-01-01

    Seed dormancy is imposed by one or more of the embryo, endosperm, and maternal tissues that belong to two generations and represent two ploidy levels. Many quantitative trait loci (QTL) have been identified for seed dormancy as measured by gross effects on reduced germination rate or delayed germination in crop or model plants. This research developed an endosperm genotype−based genetic approach to determine specific tissues through which a mapped QTL regulates germination using rice as a model. This approach involves testing germination velocity for partially after-ripened seeds harvested from single plants heterozygous for a tested QTL and genotyping endosperms from individual germinated and nongerminated seeds with a codominant DNA marker located on the QTL peak region. Information collected about the QTL includes genotypic frequencies in germinated and/or nongerminated subpopulations; allelic frequency distributions during a germination period; endosperm or embryo genotypic differences in germination velocity; and genotypic frequencies for gametes involved in the double fertilization to form the sampled seeds. Using this approach, the seed dormancy loci SD12, SD1-2, and SD7-1 were determined to regulate germination through the embryo, endosperm, and maternal tissues, respectively; SD12 and SD1-2 acted additively on germination velocity in the offspring tissues; and SD12 also was associated with the preferential fertilization of male gametes in rice. This new genetic approach can be used to characterize mapped genes/QTL for tissue-specific functions in endospermic seeds and for marker-assisted selection of QTL alleles before or immediately after germination in crop breeding. PMID:25480961

  4. Small RNA mediated regulation of seed germination

    PubMed Central

    Das, Shabari Sarkar; Karmakar, Prakash; Nandi, Asis Kumar; Sanan-Mishra, Neeti

    2015-01-01

    Mature seeds of most of the higher plants harbor dormant embryos and go through the complex process of germination under favorable environmental conditions. The germination process involves dynamic physiological, cellular and metabolic events that are controlled by the interplay of several gene products and different phytohormones. The small non-coding RNAs comprise key regulatory modules in the process of seed dormancy and germination. Recent studies have implicated the small RNAs in plant growth in correlation with various plant physiological processes including hormone signaling and stress response. In this review we provide a brief overview of the regulation of seed germination or dormancy while emphasizing on the current understanding of the role of small RNAs in this regard. We have also highlighted specific examples of stress responsive small RNAs in seed germination and discussed their future potential. PMID:26528301

  5. Butenolides from plant-derived smoke: natural plant-growth regulators with antagonistic actions on seed germination.

    PubMed

    Light, Marnie E; Burger, Ben V; Staerk, Dan; Kohout, Ladislav; Van Staden, Johannes

    2010-02-26

    Smoke plays an intriguing role in promoting the germination of seeds of many species following a fire. Recently, a bicyclic compound containing a condensed butenolide moiety, 3-methyl-2H-furo[2,3-c]pyran-2-one (1), was reported as a potent germination promoter from plant-derived smoke. In this study, a related butenolide, 3,4,5-trimethylfuran-2(5H)-one (2), which inhibits germination and significantly reduces the effect of 1 when applied simultaneously, was also isolated from plant-derived smoke. The interaction of these compounds with opposing actions on seed germination may have important ecological implications in a post-fire environment and could be useful molecules for understanding the events involved in breaking seed dormancy and promoting seed germination.

  6. In mouse oocytes the mitochondrion-originated germinal body-like structures accumulate mouse Vasa homologue (MVH) protein.

    PubMed

    Reunov, Arkadiy A; Reunova, Yulia A

    2015-08-01

    Mouse Vasa homologue (MVH) antibodies were applied to mouse Graafian oocytes to clarify if mitochondrion-originated germinal body-like structures, described previously by conventional electron microscopy, were associated with the germ plasm. It was found that both the mitochondrion-like structures with cristae and the germinal body-like structures that lacked any signs of cristae were labelled specifically by the anti-MVH antibody. Moreover, some granules were MVH-positive ultrastructural hybrids of the mitochondria and germinal body-like structures, the presence of which clearly supported the idea of a mitochondrial origin for the germinal body-like structures. This finding is the first evidence that mitochondrion-originated germinal body-like granules represent mouse germ plasm.

  7. Carbon Dioxide and Ethylene Control of Spore Germination in Onoclea sensibilis L.

    PubMed

    Edwards, M E

    1977-04-01

    Regulation of spore germination in the fern Onoclea sensibilis L. was investigated by applying CO(2) alone and in combination with ethylene. Sterile spores were sown aseptically on Knops solution in loosely capped culture tubes, enclosed individually in 2-liter chambers, and grown under continuous white light. When maintained in enclosed containers with the ethylene-absorbent mercuric perchlorate and with atmospheres enriched up to 2% CO(2) (v/v), spores germinated without any inhibition. Higher levels of applied CO(2) were progressively inhibitory. Inhibition by CO(2) was reversible. When CO(2) was permitted to escape and spores were exposed subsequently to ambient laboratory air, recovery from inhibition occurred within 48 hours. Also, inhibition by CO(2) was specific, since the same degree of inhibition resulted regardless of whether spores were treated with exogenous CO(2) for 48, 72, or 96 hours. The effect on germination of 1 mul/l added ethylene depended upon the amount of applied CO(2). When containers of KOH were enclosed and ambient CO(2) was absorbed, inhibition of germination by 1 mul/l exogenous ethylene was 90%. When CO(2) was applied in concentrations from 0.25 to 1.0% (v/v), CO(2) increasingly antagonized the inhibitory action of 1 mul/l added ethylene. Thus, photoinduced germination of spores was regulated by competitively interacting levels of CO(2) and ethylene.

  8. In vitro OECD test methods applied to screen the estrogenic effect of chemicals, used in Korea.

    PubMed

    Lee, Hee-Seok; Park, Eun-Jung; Han, Songyi; Oh, Gyeong-Yong; Kim, Min-Hee; Kang, Hui-Seung; Suh, Jin-Hyang; Oh, Jae-Ho; Lee, Kwang-Soo; Hwang, Myung-Sil; Moon, Guiim; Hong, Jin-Hwan; Hwang, In-Gyun

    2016-09-01

    In this study, 27 chemicals found in household products, which became an issue in Korea were screened for the agonistoc and antagonistic effects against human estrogen receptor using official Organization for Economic Cooperation and Development (OECD) in vitro assays, STTA assay using ERα-HeLa-9903 cell line and BG1Luc ER TA assay. In the case of human ER agonist screening by two assays, all tested chemicals did not show agonist effect against ER. In ER antagonist test by BG1Luc ER TA assay, five surfactants α-dodecyl-ω-hydroxypoly(oxyethylene), alcohols C16-18 ethoxylated, nonylphenol, ethoxylated, 3,6,9,12,15,18,21-heptaoxatritriacontan-1-ol, and α-dodecyl-ω-hydroxypoly(oxy-1,2-ethanediyl)) were found to exhibit weak antagonistic activities. The agonist/antagonist effects against human estrogen receptor of various chemicals, used in Korea by OECD test guideline are reported in this study. These results indicated that two OECD in vitro assays will can be applied in Korea by screening of agonistic/antagonistic effects against human ER of various chemicals. PMID:27317829

  9. High Salinity Alters the Germination Behavior of Bacillus subtilis Spores with Nutrient and Nonnutrient Germinants

    PubMed Central

    Nagler, Katja; Setlow, Peter; Li, Yong-Qing

    2014-01-01

    The effect of high NaCl concentrations on nutrient and nonnutrient germination of Bacillus subtilis spores was systematically investigated. Under all conditions, increasing NaCl concentrations caused increasing, albeit reversible, inhibition of germination. High salinity delayed and increased the heterogeneity of germination initiation, slowed the germination kinetics of individual spores and the whole spore population, and decreased the overall germination efficiency, as observed by a variety of different analytical techniques. Germination triggered by nutrients which interact with different germinant receptors (GRs) was affected differently by NaCl, suggesting that GRs are targets of NaCl inhibition. However, NaCl also inhibited GR-independent germination, suggesting that there is at least one additional target for NaCl inhibition. Strikingly, a portion of the spore population could initiate germination with l-alanine even at NaCl concentrations near saturation (∼5.4 M), suggesting that spores lack a salt-sensing system preventing them from germinating in a hostile high-salinity environment. Spores that initiated germination at very high NaCl concentrations excreted their large depot of Ca2+-pyridine-2,6-dicarboxylic acid and lost their heat resistance, but they remained in a phase-gray state in the phase-contrast microscope, suggesting that there was incomplete germination. However, some metabolic activity could be detected at up to 4.8 M NaCl. Overall, high salinity seems to exert complex effects on spore germination and outgrowth whose detailed elucidation in future investigations could give valuable insights on these processes in general. PMID:24317076

  10. In situ seed baiting to isolate germination-enhancing fungi for an epiphytic orchid, Dendrobium aphyllum (Orchidaceae).

    PubMed

    Zi, Xiao-Meng; Sheng, Chun-Ling; Goodale, Uromi Manage; Shao, Shi-Cheng; Gao, Jiang-Yun

    2014-10-01

    Orchid conservation efforts, using seeds and species-specific fungi that support seed germination, require the isolation, identification, and germination enhancement testing of symbiotic fungi. However, few studies have focused on developing such techniques for the epiphytes that constitute the majority of orchids. In this study, conducted in Xishuangbanna Tropical Botanical Garden, Yunnan, China, we used seeds of Dendrobium aphyllum, a locally endangered and medicinally valuable epiphytic orchid, to attract germination promoting fungi. Of the two fungi isolated from seed baiting, Tulasnella spp. and Trichoderma spp., Tulasnella, enhanced seed germination by 13.6 %, protocorm formation by 85.7 %, and seedling development by 45.2 % (all P < 0.0001). Epulorhiza, another seed germination promoting fungi isolated from Cymbidium mannii, also enhanced seed germination (6.5 %; P < 0.05) and protocorm formation (20.3 %; P < 0.0001), but Trichoderma suppressed seed germination by 26.4 % (P < 0.0001). Tulasnella was the only treatment that produced seedlings. Light increased seed imbibition, protocorm formation, and two-leaved seed development of Tulasnella inoculated seeds (P < 0.0001). Because the germination stage success was not dependent on fungi, we recommend that Tulasnella be introduced for facilitating D. aphyllum seed germination at the protocorm formation stage and that light be provided for increasing germination as well as further seedling development. Our findings suggest that in situ seed baiting can be used to isolate seed germination-enhancing fungi for the development of seedling production for conservation and reintroduction efforts of epiphytic orchids such as D. aphyllum.

  11. Effect of high pressure on green pea seeds germination and plantlets development

    NASA Astrophysics Data System (ADS)

    Alexandre, Elisabete M. C.; Carvalho, Andreia M.; Saraiva, Jorge A.

    2014-01-01

    The aim of this work was to study the impact of high pressure (50 MPa, 10 min) on germination of pea seeds with different imbibition times (0, 12 and 36 h). The parameters analysed were the percentage of germinated seeds, length of roots and stems, number of leaves developed and the weight of young plantlets. Peroxidase (POD), polyphenol oxidase (PPO), pectin methylesterase (PME) and total proteolytic activity were analysed in seeds after the pressure treatment and in leaves after the germination period. Results showed that 50 MPa applied during 10 min retarded the germination onset and inhibited seeds to germinate. The pressure treatment increased and decreased the length of roots and stems, respectively. The number of leaves per germinated seed decreased with the pressure treatment. Enzymatic activities of seeds showed that only total proteolytic activity was significantly reduced by pressure and only for 0 h of imbibition. POD and PPO activities determined in leaves of the plantlets increased with the pressure treatment, while PME activity also increased but only for 12 h of imbibition and total proteolytic activity decreased.

  12. Acid rain and pollen germination in corn.

    PubMed

    Wertheim, F S; Craker, L E

    1987-01-01

    The properties of an acid rain episode that could influence the germination of pollen in corn, Zea mays L., were evaluated by treating silks with a simulated acid rain and measuring the subsequent germination of pollen on the silks. The data indicated that acid rain creates an inhospitable environment for pollen germination on the silk surface. Reduced germination appeared directly related to the acidity of the rain, but not the sulphate concentration. Rinsing silks with a pH 5.6 rain after treatment with a pH 2.6 rain did not increase pollen germination above that on silks treated only with a pH 2.6 rain, suggesting the reduced germination was due to physical and/or chemical modifications of the silk surface and not to residual acid on the tissue. Pollen germination on silks was inhibited even when silk tissue was exposed to a simulated rain of pH 2.6 for <1.5min.

  13. Algebraic determination of the evolutionary stable germination fraction.

    PubMed

    Valleriani, Angelo

    2005-11-01

    In this article, we consider a bet-hedging model with density dependence for germination behavior of dormant seeds. We show how to compute accurate values of the evolutionary stable germination fraction using a method based on expansion around the average seed bank size. The expansion is made up to the fourth order and is expressed in terms of the first four moments of the distribution of the year-to-year variation in the average yield per adult plant. This method leads to a simple algebraic equation, which can be solved without recurring to simulations of the seed bank dynamics. We first show the analytical derivation under general assumptions about the effect of density dependence. We then test our results with a numerical analysis where an explicit form of the density dependence has been taken.

  14. 7 CFR 201.30a - Date of test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... REGULATIONS Labeling Vegetable Seeds § 201.30a Date of test. When the percentage of germination is required to be shown, the label shall show the month and year in which the germination test was completed. No... germination test was completed and the date of transportation or delivery for transportation in...

  15. 7 CFR 201.22 - Date of test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... which the germination test was completed. No more than 5 calendar months shall have elapsed between the last day of the month in which the germination test was completed and the date of transportation or... of the month in which the germination test was completed prior to packaging and the date...

  16. 7 CFR 201.30a - Date of test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS Labeling Vegetable Seeds § 201.30a Date of test. When the percentage of germination is required to be shown, the label shall show the month and year in which the germination test was completed. No... germination test was completed and the date of transportation or delivery for transportation in...

  17. 7 CFR 201.30a - Date of test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... REGULATIONS Labeling Vegetable Seeds § 201.30a Date of test. When the percentage of germination is required to be shown, the label shall show the month and year in which the germination test was completed. No... germination test was completed and the date of transportation or delivery for transportation in...

  18. 7 CFR 201.22 - Date of test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... which the germination test was completed. No more than 5 calendar months shall have elapsed between the last day of the month in which the germination test was completed and the date of transportation or... of the month in which the germination test was completed prior to packaging and the date...

  19. 7 CFR 201.30a - Date of test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS Labeling Vegetable Seeds § 201.30a Date of test. When the percentage of germination is required to be shown, the label shall show the month and year in which the germination test was completed. No... germination test was completed and the date of transportation or delivery for transportation in...

  20. 7 CFR 201.22 - Date of test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... which the germination test was completed. No more than 5 calendar months shall have elapsed between the last day of the month in which the germination test was completed and the date of transportation or... of the month in which the germination test was completed prior to packaging and the date...

  1. 7 CFR 201.22 - Date of test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... which the germination test was completed. No more than 5 calendar months shall have elapsed between the last day of the month in which the germination test was completed and the date of transportation or... of the month in which the germination test was completed prior to packaging and the date...

  2. 7 CFR 201.22 - Date of test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... which the germination test was completed. No more than 5 calendar months shall have elapsed between the last day of the month in which the germination test was completed and the date of transportation or... of the month in which the germination test was completed prior to packaging and the date...

  3. 7 CFR 201.30a - Date of test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... REGULATIONS Labeling Vegetable Seeds § 201.30a Date of test. When the percentage of germination is required to be shown, the label shall show the month and year in which the germination test was completed. No... germination test was completed and the date of transportation or delivery for transportation in...

  4. Study of factors influencing the germination of Apera spica-venti(L.) P. Beauv. in controlled conditions.

    PubMed

    Morales, W R Meza; Vanbellinghen, C; Bodson, B; Henriet, F

    2013-01-01

    Apera spica-venti (L.) P. Beauv. is a common weed of cereal crops widely spread in Northern and Eastern Europe, Northern Asia, Siberia and Canada. Given the ability of Apera spica-venti to grow and develop in Wallonia and lack of scientific knowledge of its biology, germination tests were performed on four populations. These laboratory tests were carried on according to the standards of the International Seed Testing Association (ISTA) in order to study three key factors (composition of water solution, presence/absence of pre-chilling and temperature) influencing the germination of the seeds. Germination tests showed that a solution containing 2 g/L of KNO3 and alternating night/day temperatures between 10 degrees C and 30 degrees C favorably influence the germination of Apera spica-venti. These results in controlled conditions are a premise for greenhouse and field tests.

  5. Stimulation of lettuce seed germination by ethylene.

    PubMed

    Abeles, F B; Lonski, J

    1969-02-01

    Ethylene increased the germination of freshly imbibed lettuce (Lactuca sativa L. var. Grand Rapids) seeds. Seeds receiving either red or far-red light or darkness all showed a positive response to the gas. However, ethylene was apparently without effect on dormant seeds, those which failed to germinate after an initial red or far-red treatment. Carbon dioxide, which often acts as a competitive inhibitor of ethylene, failed to clearly reverse ethylene-enhanced seed germination. While light doubled ethylene production from the lettuce seeds, its effect was not mediated by the phytochrome system since both red and far-red light had a similar effect.

  6. Germination under Extreme Hypobaric and Hypoxic Environment

    NASA Astrophysics Data System (ADS)

    Hashimoto, Hirofumi

    Is the agriculture on Mars without a pressured greenhouse dome possible? In order to inves-tigate a possibility of plant cultivation for the space agriculture on Mars, germination rate for six species of plant, Jute, Chrysanthemum, Komatsuna, Cucumber, Okra, and Eggplant under extreme hypobaric and hypoxic condition was measured. Oxygen partial pressure was 1kPa which was equal to 1/100 of normal earth atmosphere. Seeds of Jute and Cucumber were able to germinate in six species. In the case of Jute, germination rate under the oxygen partial pressure of 1kPa was very high, 70

  7. Applying User Input to the Design and Testing of an Electronic Behavioral Health Information System for Wraparound Care Coordination

    PubMed Central

    Bruns, Eric J.; Hyde, Kelly L.; Sather, April; Hook, Alyssa; Lyon, Aaron R.

    2015-01-01

    Health information technology (HIT) and care coordination for individuals with complex needs are high priorities for quality improvement in health care. However, there is little empirical guidance about how best to design electronic health record systems and related technologies to facilitate implementation of care coordination models in behavioral health, or how best to apply user input to the design and testing process. In this paper, we describe an iterative development process that incorporated user/stakeholder perspectives at multiple points and resulted in an electronic behavioral health information system (EBHIS) specific to the wraparound care coordination model for youth with serious emotional and behavioral disorders. First, we review foundational HIT research on how EBHIS can enhance efficiency and outcomes of wraparound that was used to inform development. After describing the rationale for and functions of a prototype EBHIS for wraparound, we describe methods and results for a series of six small studies that informed system development across four phases of effort – predevelopment, development, initial user testing, and commercialization – and discuss how these results informed system design and refinement. Finally, we present next steps, challenges to dissemination, and guidance for others aiming to develop specialized behavioral health HIT. The research team's experiences reinforce the opportunity presented by EBHIS to improve care coordination for populations with complex needs, while also pointing to a litany of barriers and challenges to be overcome to implement such technologies. PMID:26060099

  8. Applying User Input to the Design and Testing of an Electronic Behavioral Health Information System for Wraparound Care Coordination.

    PubMed

    Bruns, Eric J; Hyde, Kelly L; Sather, April; Hook, Alyssa N; Lyon, Aaron R

    2016-05-01

    Health information technology (HIT) and care coordination for individuals with complex needs are high priorities for quality improvement in health care. However, there is little empirical guidance about how best to design electronic health record systems and related technologies to facilitate implementation of care coordination models in behavioral health, or how best to apply user input to the design and testing process. In this paper, we describe an iterative development process that incorporated user/stakeholder perspectives at multiple points and resulted in an electronic behavioral health information system (EBHIS) specific to the wraparound care coordination model for youth with serious emotional and behavioral disorders. First, we review foundational HIT research on how EBHIS can enhance efficiency and outcomes of wraparound that was used to inform development. After describing the rationale for and functions of a prototype EBHIS for wraparound, we describe methods and results for a series of six small studies that informed system development across four phases of effort-predevelopment, development, initial user testing, and commercialization-and discuss how these results informed system design and refinement. Finally, we present next steps, challenges to dissemination, and guidance for others aiming to develop specialized behavioral health HIT. The research team's experiences reinforce the opportunity presented by EBHIS to improve care coordination for populations with complex needs, while also pointing to a litany of barriers and challenges to be overcome to implement such technologies. PMID:26060099

  9. Applying User Input to the Design and Testing of an Electronic Behavioral Health Information System for Wraparound Care Coordination.

    PubMed

    Bruns, Eric J; Hyde, Kelly L; Sather, April; Hook, Alyssa N; Lyon, Aaron R

    2016-05-01

    Health information technology (HIT) and care coordination for individuals with complex needs are high priorities for quality improvement in health care. However, there is little empirical guidance about how best to design electronic health record systems and related technologies to facilitate implementation of care coordination models in behavioral health, or how best to apply user input to the design and testing process. In this paper, we describe an iterative development process that incorporated user/stakeholder perspectives at multiple points and resulted in an electronic behavioral health information system (EBHIS) specific to the wraparound care coordination model for youth with serious emotional and behavioral disorders. First, we review foundational HIT research on how EBHIS can enhance efficiency and outcomes of wraparound that was used to inform development. After describing the rationale for and functions of a prototype EBHIS for wraparound, we describe methods and results for a series of six small studies that informed system development across four phases of effort-predevelopment, development, initial user testing, and commercialization-and discuss how these results informed system design and refinement. Finally, we present next steps, challenges to dissemination, and guidance for others aiming to develop specialized behavioral health HIT. The research team's experiences reinforce the opportunity presented by EBHIS to improve care coordination for populations with complex needs, while also pointing to a litany of barriers and challenges to be overcome to implement such technologies.

  10. Genome-Wide Association Study Identifies Loci for Salt Tolerance during Germination in Autotetraploid Alfalfa (Medicargo sativa L.) using Genotyping by Sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : In this study, we used a diverse panel of alfalfa accessions to identify molecular markers associated with salt tolerance during germination by genome-wide association (GWA) mapping and genotyping-by-sequencing (GBS). Three levels of salt treatments were applied during seed germination. Phenotypic...

  11. Effect of marble industry effluent on seed germination, post germinative growth and productivity of Zea mays L.

    PubMed

    Akbar, Fazal; Hadi, Fazal; Ullah, Zakir; Zia, Muhammad Amir

    2007-11-15

    A green house study was conducted at the University of Malakand, NWFP, Pakistan to evaluate the effect of marble industry effluent on soil pH, germination, post germinative growth and productivity of maize. The experiment was conducted in triplicate form for each treatment and tape water was used as control (T0). Effluents were diluted with tap water at concentration of 20% (T1), 40% (T2), 60% (T3), 80% (T4) and also used 100% (T5) concentration in 4 kg soil pot(-1) and plants were grown for 90 days. Results showed that there was a linear increase in pH of soil with increase in effluent concentration while germination, root length and stem girth was enhanced and found maximum at 40% concentration of effluent applied. The shoot length and root dry biomass was depressed as compared to control. It is concluded from the present study that marble industry effluent can be used as a fertilizer in low concentration especially for highly acidic soil but there is still need to carry out series of greenhouse and field trials to ascertain the fertilizer potentials of this effluent for maize crop. PMID:19090297

  12. Seedling survival of Handroanthus impetiginosus (Mart ex DC) Mattos in a semi-arid environment through modified germination speed and post-germination desiccation tolerance.

    PubMed

    Martins, J R; Edvaldo, A A S; Alvarenga, A A; Rodrigues, A C; Ribeiro, D E; Toorop, P E

    2015-11-01

    Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone), but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.

  13. Seedling survival of Handroanthus impetiginosus (Mart ex DC) Mattos in a semi-arid environment through modified germination speed and post-germination desiccation tolerance.

    PubMed

    Martins, J R; Edvaldo, A A S; Alvarenga, A A; Rodrigues, A C; Ribeiro, D E; Toorop, P E

    2015-11-01

    Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone), but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse. PMID:26675900

  14. Using hyperspectral imaging to determine germination of native Australian plant seeds.

    PubMed

    Nansen, Christian; Zhao, Genpin; Dakin, Nicole; Zhao, Chunhui; Turner, Shane R

    2015-04-01

    We investigated the ability to accurately and non-destructively determine the germination of three native Australian tree species, Acacia cowleana Tate (Fabaceae), Banksia prionotes L.F. (Proteaceae), and Corymbia calophylla (Lindl.) K.D. Hill & L.A.S. Johnson (Myrtaceae) based on hyperspectral imaging data. While similar studies have been conducted on agricultural and horticultural seeds, we are unaware of any published studies involving reflectance-based assessments of the germination of tree seeds. Hyperspectral imaging data (110 narrow spectral bands from 423.6nm to 878.9nm) were acquired of individual seeds after 0, 1, 2, 5, 10, 20, 30, and 50days of standardized rapid ageing. At each time point, seeds were subjected to hyperspectral imaging to obtain reflectance profiles from individual seeds. A standard germination test was performed, and we predicted that loss of germination was associated with a significant change in seed coat reflectance profiles. Forward linear discriminant analysis (LDA) was used to select the 10 spectral bands with the highest contribution to classifications of the three species. In all species, germination decreased from over 90% to below 20% in about 10-30days of experimental ageing. P50 values (equal to 50% germination) for each species were 19.3 (A. cowleana), 7.0 (B. prionotes) and 22.9 (C. calophylla) days. Based on independent validation of classifications of hyperspectral imaging data, we found that germination of Acacia and Corymbia seeds could be classified with over 85% accuracy, while it was about 80% for Banksia seeds. The selected spectral bands in each LDA-based classification were located near known pigment peaks involved in photosynthesis and/or near spectral bands used in published indices to predict chlorophyll or nitrogen content in leaves. The results suggested that seed germination may be successfully classified (predicted) based on reflectance in narrow spectral bands associated with the primary metabolism

  15. Germination Responses to Water Potential in Neotropical Pioneers Suggest Large-seeded Species Take More Risks

    PubMed Central

    Daws, Matthew I.; Crabtree, Lora M.; Dalling, James W.; Mullins, Christopher E.; Burslem, David F. R. P.

    2008-01-01

    Background and Aims In neotropical forests, very small-seeded pioneer species (<0·1 mg seed mass) recruit preferentially in small tree fall gaps and at gap edges, but large-seeded pioneers do not. Since water availability is related to gap size, these differences in microsite preference may reflect in part species-specific differences in germination at reduced water potentials. Methods For 14 neotropical pioneer species, the hypothesis is tested that small-seeded species, with shallow initial rooting depths, reduce the risks associated with desiccation by germinating more slowly and at higher water potentials than large-seeded species. Key Results Germination occurred both more quickly and at lower water potentials with increasing seed mass. For example, Ochroma pyramidale (seed mass 5·5 mg) had a time to 50 % germination (T50) of 2·8 d and a median base potential for germination (ψb50) of −1·8 MPa while Clidemia quinquenervia (seed mass 0·017 mg) had a T50 of 17·6 d and ψb50 of −1·1 MPa. Conclusions These data suggest that small-seeded species germinate only in comparatively moist microsites, such as small canopy gaps, which may reduce the risk of drought-induced mortality. Conversely, large-seeded species are able to germinate in the drier environment of large gaps, where they benefit by enhanced seedling growth in a high irradiance environment. The positive association of seed size and canopy gap size for optimal seedling establishment is maintained by differential germination responses to soil water availability coupled with the scaling of radicle growth rate and seed size, which collectively confer greater drought tolerance on large-seeded species. PMID:18840874

  16. Does thermal time for germination vary among populations of a tree legume (Peltophorum dubium)?

    PubMed

    Andrade, L F D; Cardoso, V J M

    2016-04-19

    Few works report the use of degree-days (DD) - used in crops to predict events and schedule management activities - to describe the germination of tropical trees. The cardinal temperatures (base, optimum and ceiling temperature) for germination of the species may vary depending on the seed provenance. Peltophorum dubium (Spreng.) Taub. is an early successional leguminous tree widely distributed in South America, often occurring as cultivated or naturalized trees, thus considered to be a good example for testing DD model in tree species. The main objective of this study was to describe the seed germination response of different populations of P. dubium as function of DD accumulation during germination assays in semi-controlled (fluctuating temperatures) conditions. Germination assays with manually scarified seeds sown in aluminum sheet trays filled with a composed substrate were performed under greenhouse conditions at different times. Three methods were employed in order to describe the accumulation of thermal time throughout the assays and, considering the seed lot and sowing time, a trapezoid area method was relatively more effective in describing the germination. The germination curves of P. dubium seeds from different populations, expressed in degree-days estimated directly from temperature records schedules, tend to be more clustered suggesting little variation among thermal time requirements in different seed provenances. Otherwise, the thermal time requirement can vary depending on the time of sowing, and any increase in DD requirement when the assays were performed under higher mean temperatures can be related to a thermal effect on the germination of scarified seeds. PMID:27097080

  17. Germination and Plantlet Regeneration of Encapsulated Microshoots of Aromatic Rice (Oryza sativa L. Cv. MRQ 74)

    PubMed Central

    Taha, Rosna Mat; Saleh, Azani; Mahmad, Noraini; Hasbullah, Nor Azlina; Mohajer, Sadegh

    2012-01-01

    Plant tissues such as somatic embryos, apical shoot tips, axillary shoot buds, embryogenic calli, and protocom-like bodies are potential micropropagules that have been considered for creating synthetic seeds. In the present study, 3–5 mm microshoots of Oryza sativa L. Cv. MRQ 74 were used as explant sources for obtaining synthetic seeds. Microshoots were induced from stem explants on Murashige and Skoog (MS) medium supplemented with 1.5 mg/L benzylaminopurine (BAP). They were encapsulated in 3% (w/v) sodium alginate, 3% sucrose, 0.1 mg/L BAP, and 0.1 mg/L α-Naphthalene acetic acid (NAA). Germination and plantlet regeneration of the encapsulated seeds were tested by culturing them on various germination media. The effect of storage period (15–30 days) was also investigated. The maximum germination and plantlet regeneration (100.0%) were recorded on MS media containing 3% sucrose and 0.8% agar with and without 0.1 mg/L BAP. However, a low germination rate (6.67%) was obtained using top soil as a sowing substrate. The germination rate of the encapsulated microshoots decreased from 93.33% to 3.33% after 30 days of storage at 4°C in the dark. Therefore, further research is being done to improve the germination rate of the synthetic seeds. PMID:22919338

  18. Factors Affecting Germination of Puccinia jaceae var. solstitialis Teliospores from Yellow Starthistle.

    PubMed

    Bruckart, William L; Eskandari, Farivar

    2002-04-01

    ABSTRACT The rust fungus Puccinia jaceae var. solstitialis is a candidate for biological control of yellow starthistle (YST). Part of the risk assessment includes determining if safflower seedlings are susceptible to infection by teliospores of P. jaceae. A protocol for germination of P. jaceae teliospores is needed to verify that teliospores used in comparative studies are viable. The protocol developed from this research has two steps: first, priming teliospores on water agar at 4 degrees C in the dark, and second, incubating them at warmer temperatures for 1 week in the presence of an exogenous stimulator. Priming longer than 4 weeks resulted in significantly greater germination than priming for shorter periods. Sources of effective stimulator included seeds and seedlings of YST or safflower. The greatest germination occurred during incubation at 18 degrees C in the dark. Teliospore germination was reduced after incubation with a 12- or 14-h photoperiod. A low percentage (<20%) of teliospores of two isolates germinated after 44 and 96 weeks of dry storage at room temperature; samples of each isolate tested after that did not germinate. Data indicate teliospores of several isolates of P. jaceae are viable, and the protocol will be used to prepare teliospores of P. jaceae for comparative studies with P. carthami on safflower seedlings.

  19. Inhibition of DNA polymerase λ and associated inflammatory activities of extracts from steamed germinated soybeans.

    PubMed

    Mizushina, Yoshiyuki; Kuriyama, Isoko; Yoshida, Hiromi

    2014-04-01

    During the screening of selective DNA polymerase (pol) inhibitors from more than 50 plant food materials, we found that the extract from steamed germinated soybeans (Glycine max L.) inhibited human pol λ activity. Among the three processed soybean samples tested (boiled soybeans, steamed soybeans, and steamed germinated soybeans), both the hot water extract and organic solvent extract from the steamed germinated soybeans had the strongest pol λ inhibition. We previously isolated two glucosyl compounds, a cerebroside (glucosyl ceramide, AS-1-4, compound ) and a steroidal glycoside (eleutheroside A, compound ), from dried soybean, and these compounds were prevalent in the extracts of the steamed germinated soybeans as pol inhibitors. The hot water and organic solvent extracts of the steamed germinated soybeans and compounds and selectively inhibited the activity of eukaryotic pol λ in vitro but did not influence the activities of other eukaryotic pols, including those from the A-family (pol γ), B-family (pols α, δ, and ε), and Y-family (pols η, ι, and κ), and also showed no effect on the activity of pol β, which is of the same family (X) as pol λ. The tendency for in vitro pol λ inhibition by these extracts and compounds showed a positive correlation with the in vivo suppression of TPA (12-O-tetradecanoylphorbol-13-acetate)-induced inflammation in mouse ear. These results suggest that steamed germinated soybeans, especially the glucosyl compound components, may be useful for their anti-inflammatory properties.

  20. The Role of Water in Germination.

    ERIC Educational Resources Information Center

    Bicak, Charles J.

    1986-01-01

    Describes a laboratory experiment which focuses on the importance of water in germination and seedling emergence. Discusses the activity's design, expected results, and possible application. Offers suggestions for extending the experiment. (ML)

  1. A Role for Brassinosteroids in Germination in Arabidopsis1

    PubMed Central

    Steber, Camille M.; McCourt, Peter

    2001-01-01

    This paper presents evidence that plant brassinosteroid (BR) hormones play a role in promoting germination. It has long been recognized that seed dormancy and germination are regulated by the plant hormones abscisic acid (ABA) and gibberellin (GA). These two hormones act antagonistically with each other. ABA induces seed dormancy in maturing embryos and inhibits germination of seeds. GA breaks seed dormancy and promotes germination. Severe mutations in GA biosynthetic genes in Arabidopsis, such as ga1-3, result in a requirement for GA application to germinate. Whereas previous work has shown that BRs play a critical role in controlling cell elongation, cell division, and skotomorphogenesis, no germination phenotypes have been reported in BR mutants. We show that BR rescues the germination phenotype of severe GA biosynthetic mutants and of the GA-insensitive mutant sleepy1. This result shows that BR stimulates germination and raises the possibility that BR is needed for normal germination. If true, we would expect to detect a germination phenotype in BR mutants. We found that BR mutants exhibit a germination phenotype in the presence of ABA. Germination of both the BR biosynthetic mutant det2-1 and the BR-insensitive mutant bri1-1 is more strongly inhibited by ABA than is germination of wild type. Thus, the BR signal is needed to overcome inhibition of germination by ABA. Taken together, these results point to a role for BRs in stimulating germination. PMID:11161033

  2. Oxygen dependency of germinating Brassica seeds.

    PubMed

    Park, Myoung Ryoul; Hasenstein, Karl H

    2016-02-01

    Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

  3. Oxygen dependency of germinating Brassica seeds

    NASA Astrophysics Data System (ADS)

    Park, Myoung Ryoul; Hasenstein, Karl H.

    2016-02-01

    Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

  4. Oxygen dependency of germinating Brassica seeds.

    PubMed

    Park, Myoung Ryoul; Hasenstein, Karl H

    2016-02-01

    Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions. PMID:26948011

  5. [Screening antihydatid drugs using cultivated germinal cells of Echinococcus granulosus].

    PubMed

    Feng, J J; Xiao, S H; Guo, H F; Shen, B G; Jiao, W

    1993-01-01

    Germinal cells isolated from Echinococcus granulosus cysts harbored in mice have been maintained in an in vitro culture system containing RPMI 1640 supplemented by 20% calf serum, and used as a model for screening anti-hydatid drugs. When the germinal cells were maintained in the medium for 6 days, the cell proliferation rate was rather high in the first four days but declined in the last two days. In screening drugs, 1.4 x 10(6) germinal cells were exposed to known effective drugs against metacestodes of E. granulosus in mice, such as mebendazole (Meb), albendazole (Alb) or praziquantel (Pra) at various concentrations. One to three days after exposure, cell counts were made daily in 3 samples of each drug concentration. The mean cell number of each group was compared with that of the control and the inhibition rate of the cell was then calculated. The results showed that the minimal effective concentrations of Meb, Alb and Pra, were 1.0 (48 h), 2.5 (24 h) and 10.0 (72 h) micrograms/ml, respectively, while the inhibition rates of the cell were 34.1, 55.7 and 18.5%. Interestingly, the in vitro effects of Meb, Alb and Pra were consistent to those obtained from the in vivo tests, ie Meb > Alb > Pra. Nevertheless, after exposure of germinal cells to Meb at 2.5 micrograms/ml for 24 h, the cells appeared in roughness, indistinction, shrunk or swelling, collapse, deformation and hole-like feature detected by light microscopy and scanning electron-microscopy, while the ultrastructure alterations of the cells noted by transmission electron-microscopy were lysis in cytoplasm, disruption or disappearance of nucleus and even darkness of the whole cell.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Comparison of germination and seed vigor of sunflower in two contaminated soils of different texture

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Han, Jaemaro; Lee, Jong Keun; Kim, Jae Young

    2014-05-01

    Phytoremediation as an emerging low-cost and ecologically friendly alternative to the conventional soil remediation technologies has gained a great deal of attention and into lots of research. As a kind of the methods that use of green plants to remediate heavy metals contaminated soils, the early growth status of plant seeds in the contaminated environmental directly affects the effect of phytoremediation. Germination test in the water (aqueous solution of heavy metal) is generally used for assessing heavy metal phytotoxicity and possibility of plant growth, but there is a limit. Because soil is commonly main target of phytoremediation, not the water. The bioavailability of heavy metals in the soil also depends on the texture. So soil texture is an important factor of phytoremediation effect. Sunflower is the representative species which have good tolerance to various heavy metals; furthermore, the seeds of sunflower can be used as the raw-material for producing bio-diesel. The objectives of this research were to investigate germination rate of sunflowers in various heavy metal contaminated soils and to compare the seedling vigor index (SVI) of sunflower in two contaminated soils of different texture. Sunflower (Helianthusannuus L.) seeds were obtained from a commercial market. In order to prove the soil texture effect on heavy metal contaminated soil, germination tests in soil were conducted with two different types of soil texture (i.e., loam soil and sandy loam soil) classified by soil textural triangle (defined by USDA) including representative soil texture of Korea. Germination tests in soil were conducted using KS I ISO 11260-1 (2005) for reference that sunflower seeds were incubated for 7 days in dark at 25 ± 1 Celsius degree. The target heavy metals are Nickel (Ni) and Zinc (Zn). The Ni and Zn concentrations were 0, 10, 50, 100, 200, 300, 500 mg-Ni/kg-dry soil, and 0, 10, 50, 100, 300, 500, 900 mg-Zn/kg-dry soil, respectively. After germination test for 7

  7. 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.

  8. 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

  9. Aminopeptidase activity from germinated jojoba cotyledons.

    PubMed

    Johnson, R; Storey, R

    1985-11-01

    One major and two minor aminopeptidase activities from germinated jojoba (Simmondsia chinensis) cotyledon extracts were separated by ammonium sulfate precipitation and chromatofocusing. None of the activities were inhibited by 1,10 phenanthroline.The major aminopeptidase, purified 260-fold, showed a pH optimum of 6.9 with leucine-p-nitroanilide as substrate, a molecular weight estimated at 14,200 by electrophoretic analysis, and an isoelectric point of 4.5 according to the chromatofocusing pattern. Activity was inhibited by p-chloromercuribenzoate, slightly stimulated by 1,10 phenanthroline and 2-mercaptoethanol, and not influenced by Mg(2+) or diethyl pyrocarbonate. Inhibition by p-chloromercuribenzoate was prevented by the presence of cysteine in the assay. Leucine-p-nitroanilide and leucine-beta-naphthylamide were the most rapidly hydrolyzed of 11 carboxy-terminal end blocked synthetic substrates tested. No activity on endopeptidase or carboxypeptidase specific substrates was detected. The major aminopeptidase showed activity on a saline soluble, jojoba seed protein preparation and we suggest a possible physiological role for the enzyme in the concerted degradation of globulin reserve proteins during cotyledon senescence.

  10. NDT testing by holographic interferometry applied to the structural diagnostic of artwork conservations by means of sound wave excitation

    NASA Astrophysics Data System (ADS)

    Vincitorio, Fabio; Ramil, Alberto; López, Ana J.; Saavedra, Emilio; Yáñez, Armando

    2008-06-01

    Techniques based on holographic interferometry have achieved a mature state of non destructive testing applications in industry and nowadays they are rising as interesting and promising tools in the field of conservation practices; giving information about the condition of structural integration of artworks. In the practice of these techniques it is necessary to generate a relative deformation in the object under study. Depending of the characteristics of the artwork, different methods may be used to achieve the desired displacement; being thermal excitation by means of filament lamps and wave sounds generated by speakers the most common. By applying these methods the deformation process usually involves a large area of the object, which limits the information obtained of a finite region. However, the use of a wave sound emitter of small dimensions, like a low power monotone buzzer, allows to decrease the affected area and to obtain information about the structural integrity of localized points of the surface. In the present study conventional double exposure double way holographic technique based on holographic films was used to obtain an out of plain deformation pattern caused by a sound emitter in an oil painting which has suffered heavy structural damage. Optimization of the excitation sound wave characteristics (frequency and amplitude) and the adjustment and calibration of the experimental set up, in order to obtain precise information about the physical and mechanical integrity of localized points of the painting are reported.

  11. Test-retest reliability of a new technique with pressure algometry applied to teeth in healthy Chinese individuals.

    PubMed

    Liu, Ran; Gu, Xinyu; Zhang, Jinglu; Yu, Linfeng; Chen, Wenjing; Wang, Kelun; Svensson, Peter

    2016-06-01

    Pressure pain thresholds (PPTs) have been shown to be useful measures of mechanical pain sensitivity in deep tissues. However, clinical methods for measuring mechanical allodynia or hyperalgesia in teeth have not been reported. The aim of this study was to assess the reliability of PPTs in periodontal ligament of healthy Chinese participants. Twenty healthy young adults participated. Pressure pain thresholds were measured at six teeth and in two directions. The tests included three consecutive trials, in two separate sessions, which were performed on the first day by one examiner. After 1-3 wk, an identical protocol was carried out by two examiners, also in two separate sessions. There were no significant differences between repeated measures for all teeth. The PPTs had excellent reliability with high intraclass coefficients (ICCs) across different sessions (ICC: 0.871-0.956), days (ICC: 0.879-0.951), and examiners (ICC: 0.845-0.950). Pressure pain thresholds applied to the teeth have excellent intra- and inter-examiner agreement in healthy participants. This method may be proposed as an easy and reliable technique to assess mechanical pain sensitivity (e.g. mechanical allodynia and hyperalgesia) in the periodontal ligament, which is associated with endodontic or periodontal conditions. PMID:27017942

  12. Changes in biogenic amines in mature and germinating legume seeds and their behavior during cooking.

    PubMed

    Shalaby, A R

    2000-02-01

    Ungerminated legume seeds (broad bean, chick pea and lupine) were contained all tested biogenic amines. Tryptamine (TRY) was the main biogenic amine detected, and its concentration considerably increased during the germination. beta-Phenylethylamine (PHE) was detected in small amounts and its concentration slowly increased during germination. The concentration of tyramine (TYR) showed a fluctuation pattern of changes during germination in all tested legumes. The concentrations of cadaverine (CAD) and putrescine (PUT) increased during the germination period in all tested grains. However, histamine (HIS) showed a fluctuated pattern of changes in both broad bean and lupine, and a gradual increase in chick pea. Spermidine (SPD) and spermine (SPM) contents of broad bean and chick pea showed a fluctuation pattern of change, while, a decrement trend of change was recorded for lupine along the germination period. By cooking, legume samples became free of biogenic amines which appeared in the boiling water. Heat treatment seems to have little effect on the concentration of biogenic amines in legume sprouts. The amounts of biogenic amines detected in the boiling water are less than the initial amounts of the sprouts (expected amounts).

  13. [Effects of bryophytes in dark coniferous forest of Changbai Mountains on three conifers seed germination and seedling growth].

    PubMed

    Lin, Fei; Hao, Zhanqing; Ye, Ji; Jiang, Ping

    2006-08-01

    This paper studied the effects of Hylocomium splendens and Rhytidiadelphus triquetrus, the main bryophytes in dark coniferous forests of Changbai Mountains, on the seed germination and seedling growth of Pinus koraiensis, Picea koraiensis and Larix olgensis. The results indicated that at definite concentrations, the water extract of H. splendens inhibited Picea koraiensis seed germination, while that of R. triquetrus promoted it. Although the water extracts of the two bryophytes had no obvious effects on the seed germination of Picea koraiensis and Larix olgensis, they expedited the occurrence of the tree species' daily germination peak. The water extracts of test bryophytes inhibited the seedling growth of P. koraiensis and Picea koraiensis, but promoted that of Larix olgensis. The living shoots of the two bryophytes had no obvious effects on the seed germination of Picea koraiensis and Larix olgensis, but delayed the daily germination peak of Picea koraiensis while promoted that of Larix olgensis, andthe killed shoots inhibited the seed germination of all test tree species. Living shoots in larger amounts promoted the seedling growth of Picea koraiensis and Larix olgensis, but killed shoots were inadverse.

  14. [Seed germination of four tree species from the tropical dry forest of Valle del Cauca, Colombia].

    PubMed

    Vargas Figueroa, Jhon Alexander; Duque Palacio, Olga Lucía; Torres González, Alba Marina

    2015-03-01

    The ecological restoration strategies for highly threatened ecosystems such as the tropical dry forest, depend on the knowledge of limiting factors of biological processes for the different species. Some of these include aspects such as germination and seed longevity of typical species present in those forests. In this study, we evaluated the effect of light and temperature on seed germination of two Fabaceae (Samanea saman and Jacaranda caucana) and two Bignoniaceae (Pithecellobium dulce and Tabebuia rosea) species having potential use in restoration, and we analyzed the seed storage behavior of these species for a three months period. To study the light effect, four levels of light quality on seeds were used (photoperiod of 12 hours of white light, darkness and light enriched in red and far-red, both for an hour each day), and we combined them with three levels of alternated temperatures (20/25, 20/30 and 25/30*C-16/8h). For the storage behavior, two levels of seed moisture content particular for each species were used (low: 3.5-6.1% and high: 8.3-13.8%), with three storage temperatures (20, 5 and -20 degrees C) and two storage times (one and three months). The criterion for germination was radicle emergence which was measured in four replicates per treatment, and was expressed as percentage of germination (PG). There were significant differences in germination of Samanea saman and Jacaranda caucana among light and temperature treatments, with the lowest value in darkness treatments, whereas germination of Pithecellobium dulce and Tabebuia rosea did not differ between treatments (PG>90%). The most suitable temperature regime to promote germination in all species was 25/30 degrees C. These four species showed an orthodox seed storage behavior. We concluded that seeds of R dulce, J. caucana and T. rosea did not have an apparent influence of all light conditions tested in their germination response, which might confer advantages in colonization and establishment

  15. Effect of Fungicides and Plant Extracts on the Conidial Germination of Colletotrichum gloeosporioides Causing Mango Anthracnose

    PubMed Central

    Imtiaj, Ahmed; Rahman, Syed Ajijur; Alam, Shahidul; Parvin, Rehana; Farhana, Khandaker Mursheda; Kim, Sang-Beom

    2005-01-01

    In Northern Bangladesh, generally mango trees are planted as agroforest that gives higher Net Present Value (NPV) than traditional agriculture. Mango anthracnose caused by Colletotrichum gloeosporioides Penz. is seen as a very destructive and widely distributed disease, which results in poor market value. Five fungicides such as Cupravit, Bavistin, Dithane M-45, Thiovit and Redomil were tested against conidial germination of C. gloeosporioides. Dithane M-45 and Redomil were the most effective when the conidia were immersed for 10~20 minutes at 500~1000 ppm concentrations. Antifungal activities of 13 plant extracts were tested against conidial germination of C. gloeosporioides. Conidial germination of C. gloeosporioides was completely inhibited in Curcuma longa (leaf and rhizome), Tagetes erecta (leaf) and Zingiber officinales (rhizome) after 15 minutes of incubation respectively. PMID:24049501

  16. Effect of Fungicides and Plant Extracts on the Conidial Germination of Colletotrichum gloeosporioides Causing Mango Anthracnose.

    PubMed

    Imtiaj, Ahmed; Rahman, Syed Ajijur; Alam, Shahidul; Parvin, Rehana; Farhana, Khandaker Mursheda; Kim, Sang-Beom; Lee, Tae-Soo

    2005-12-01

    In Northern Bangladesh, generally mango trees are planted as agroforest that gives higher Net Present Value (NPV) than traditional agriculture. Mango anthracnose caused by Colletotrichum gloeosporioides Penz. is seen as a very destructive and widely distributed disease, which results in poor market value. Five fungicides such as Cupravit, Bavistin, Dithane M-45, Thiovit and Redomil were tested against conidial germination of C. gloeosporioides. Dithane M-45 and Redomil were the most effective when the conidia were immersed for 10~20 minutes at 500~1000 ppm concentrations. Antifungal activities of 13 plant extracts were tested against conidial germination of C. gloeosporioides. Conidial germination of C. gloeosporioides was completely inhibited in Curcuma longa (leaf and rhizome), Tagetes erecta (leaf) and Zingiber officinales (rhizome) after 15 minutes of incubation respectively. PMID:24049501

  17. Germination characteristics of Andropogon virginicus L

    SciTech Connect

    Farmer, R.E. Jr.; Cunningham, M.; Brown, J.E.

    1980-12-01

    The natural occurrence of broomsedge (Andropogon virginicus L.) as a pioneer species on orphan strip mines with acid soils (pH 3.0-4.0) and other areas of low fertility suggests that it may have value in revegetation systems for disturbed sites. This study was conducted to delineate seed dormancy and germination characteristics important to developing seeding procedures. Freshly collected seed from east Tennessee germinated to about 50 percent under light at 20-30/sup 0/C, but did not germinate at lower temperatures. If stored in a low-humidity, low-temperature environment, seed developed a deeper dormancy, which was broken by moist chilling. This chilling first enabled germination at high temperatures and in light; as chilling time increased, seed developed a capability for germination in the dark and at low temperatures. In a preliminary seeding trial on an acid (pH 4.0) minesoil, broomsedge survived and grew better than commonly used species such as Festuca arundinacea and Eragrostis curvula.

  18. Effect of abscisic and gibberellic acids on malate synthase transcripts in germinating castor bean seeds.

    PubMed

    Rodriguez, D; Dommes, J; Northcote, D H

    1987-05-01

    Several clones complementary to malate synthase mRNA have been identified in a complementary-DNA library to mRNA from castor bean endosperm. One of these clones has been used as a probe to measure levels of transcripts during seed germination and the effects of gibberellic acid and abscisic acid on these levels have been examined.Malate synthase transcripts increased during germination and GA3 advanced their appearance in the endosperm. Exogenously applied ABA inhibited the accumulation of transcripts over a time course of germination but the addition of GA3 counteracted its inhibitory effects. The data confirmed previous reports which indicated that the action of both growth regulators was on transcript accumulation and that there is a coordinated induction of the enzymes involved in the lipid metabolism in oil seeds.

  19. Seed Germination Ecology of the Cold Desert Annual Isatis violascens (Brassicaceae): Two Levels of Physiological Dormancy and Role of the Pericarp.

    PubMed

    Zhou, Yuan M; Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

    2015-01-01

    The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA3) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in an experimental garden. The pericarp has a role in mechanically inhibiting germination of fresh seeds and promotes germination of nondormant seeds, but it does not facilitate formation of a persistent seed bank. Seeds in silicles in watered soil began to germinate earlier in autumn and germinated to higher percentages than isolated seeds. Sixty-two percent of seeds in the buried silicles germinated by the end of the first spring, and only 3% remained nongerminated and viable. Twenty to twenty-five percent of the seeds have nondeep physiological dormancy (PD) and 75-80% intermediate PD. Seeds with nondeep PD afterripen in summer and germinate inside the silicles in autumn if the soil is moist. Afterripening during summer significantly decreased the amount of cold stratification required to break intermediate PD. The presence of both nondeep and intermediate PD in the seed cohort may be a bet-hedging strategy.

  20. Seed Germination Ecology of the Cold Desert Annual Isatis violascens (Brassicaceae): Two Levels of Physiological Dormancy and Role of the Pericarp.

    PubMed

    Zhou, Yuan M; Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

    2015-01-01

    The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA3) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in an experimental garden. The pericarp has a role in mechanically inhibiting germination of fresh seeds and promotes germination of nondormant seeds, but it does not facilitate formation of a persistent seed bank. Seeds in silicles in watered soil began to germinate earlier in autumn and germinated to higher percentages than isolated seeds. Sixty-two percent of seeds in the buried silicles germinated by the end of the first spring, and only 3% remained nongerminated and viable. Twenty to twenty-five percent of the seeds have nondeep physiological dormancy (PD) and 75-80% intermediate PD. Seeds with nondeep PD afterripen in summer and germinate inside the silicles in autumn if the soil is moist. Afterripening during summer significantly decreased the amount of cold stratification required to break intermediate PD. The presence of both nondeep and intermediate PD in the seed cohort may be a bet-hedging strategy. PMID:26513241

  1. The community-level effect of light on germination timing in relation to seed mass: a source of regeneration niche differentiation.

    PubMed

    Zhang, Chunhui; Willis, Charles G; Burghardt, Liana T; Qi, Wei; Liu, Kun; Souza-Filho, Paulo Roberto de Moura; Ma, Zhen; Du, Guozhen

    2014-11-01

    Within a community, species may germinate at different times so as to mitigate competition and to take advantage of different aspects of the seasonal environment (temporal niche differentiation). We illustrated a hypothesis of the combined effects of abiotic and biotic competitive factors on germination timing and the subsequent upscale effects on community assembly. We estimated the germination timing (GT) for 476 angiosperm species of the eastern Tibetan Plateau grasslands under two light treatments in the field: high (i.e. natural) light and low light. We also measured the shift in germination timing (SGT) across treatments for all species. Furthermore, we used phylogenetic comparative methods to test if GT and SGT were associated with seed mass, an important factor in competitive interactions. We found a significant positive correlation between GT and seed mass in both light treatments. Additionally, small seeds (early germinating seeds) tended to germinate later and large seeds (late germinating seeds) tended to germinate earlier under low light vs high light conditions. Low light availability can reduce temporal niche differentiation by increasing the overlap in germination time between small and large seeds. In turn, reduced temporal niche differentiation may increase competition in the process of community assembly.

  2. Seed Germination Ecology of the Cold Desert Annual Isatis violascens (Brassicaceae): Two Levels of Physiological Dormancy and Role of the Pericarp

    PubMed Central

    Tan, Dun Y.; Baskin, Carol C.; Baskin, Jerry M.

    2015-01-01

    The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA3) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in an experimental garden. The pericarp has a role in mechanically inhibiting germination of fresh seeds and promotes germination of nondormant seeds, but it does not facilitate formation of a persistent seed bank. Seeds in silicles in watered soil began to germinate earlier in autumn and germinated to higher percentages than isolated seeds. Sixty-two percent of seeds in the buried silicles germinated by the end of the first spring, and only 3% remained nongerminated and viable. Twenty to twenty-five percent of the seeds have nondeep physiological dormancy (PD) and 75–80% intermediate PD. Seeds with nondeep PD afterripen in summer and germinate inside the silicles in autumn if the soil is moist. Afterripening during summer significantly decreased the amount of cold stratification required to break intermediate PD. The presence of both nondeep and intermediate PD in the seed cohort may be a bet-hedging strategy. PMID:26513241

  3. Reexamining the Germination Phenotypes of Several Clostridium difficile Strains Suggests Another Role for the CspC Germinant Receptor

    PubMed Central

    Bhattacharjee, Disha; Francis, Michael B.; Ding, Xicheng; McAllister, Kathleen N.; Shrestha, Ritu

    2015-01-01

    ABSTRACT Clostridium difficile spore germination is essential for colonization and disease. The signals that initiate C. difficile spore germination are a combination of taurocholic acid (a bile acid) and glycine. Interestingly, the chenodeoxycholic acid class (CDCA) bile acids competitively inhibit taurocholic acid-mediated germination, suggesting that compounds that inhibit spore germination could be developed into drugs that prophylactically prevent C. difficile infection or reduce recurring disease. However, a recent report called into question the utility of such a strategy to prevent infection by describing C. difficile strains that germinated in the apparent absence of bile acids or germinated in the presence of the CDCA inhibitor. Because the mechanisms of C. difficile spore germination are beginning to be elucidated, the mechanism of germination in these particular strains could yield important information on how C. difficile spores initiate germination. Therefore, we quantified the interaction of these strains with taurocholic acid and CDCA, the rates of spore germination, the release of DPA from the spore core, and the abundance of the germinant receptor complex (CspC, CspB, and SleC). We found that strains previously observed to germinate in the absence of taurocholic acid correspond to more potent 50% effective concentrations (EC50 values; the concentrations that achieve a half-maximum germination rate) of the germinant and are still inhibited by CDCA, possibly explaining the previous observations. By comparing the germination kinetics and the abundance of proteins in the germinant receptor complex, we revised our original model for CspC-mediated activation of spore germination and propose that CspC may activate spore germination and then inhibit downstream processes. IMPORTANCE Clostridium difficile forms metabolically dormant spores that persist in the health care environment. In susceptible hosts, C. difficile spores germinate in response to certain

  4. Complexes of D-type cyclins with CDKs during maize germination.

    PubMed

    Godínez-Palma, Silvia K; García, Elpidio; Sánchez, María de la Paz; Rosas, Fernando; Vázquez-Ramos, Jorge M

    2013-12-01

    The importance of cell proliferation in plant growth and development has been well documented. The majority of studies on basic cell cycle mechanisms in plants have been at the level of gene expression and much less knowledge has accumulated in terms of protein interactions and activation. Two key proteins, cyclins and cyclin-dependent kinases (CDKs) are fundamental for cell cycle regulation and advancement. Our aim has been to understand the role of D-type cyclins and type A and B CDKs in the cell cycle taking place during a developmental process such as maize seed germination. Results indicate that three maize D-type cyclins-D2;2, D4;2, and D5;3-(G1-S cyclins by definition) bind and activate two different types of CDK-A and B1;1-in a differential way during germination. Whereas CDKA-D-type cyclin complexes are more active at early germination times than at later times, it was surprising to observe that CDKB1;1, a supposedly G2-M kinase, bound in a differential way to all D-type cyclins tested during germination. Binding to cyclin D2;2 was detectable at all germination times, forming a complex with kinase activity, whereas binding to D4;2 and D5;3 was more variable; in particular, D5;3 was only detected at late germination times. Results are discussed in terms of cell cycle advancement and its importance for seed germination.

  5. Morphology, ecophysiology and germination of seeds of the neotropical tree Alibertia patinoi (Rubiaceae).

    PubMed

    Escobar Escobar, Diego Fernando; Torres, Alba Marina

    2013-06-01

    Alibertia patinoi (Rubiaceae) is of economic and cultural importance for communities in the Colombian Pacific and Amazon regions, where it is cultivated and mature fruits are highly appreciated and consumed. Since there is a lack of knowledge of the seed physiology of this species, we describe here the germination behavior and morphometry of seeds of Alibertia patinoi, and relate them to its habitat. Fruits were collected from a mixed food crop and a commercial plantation in Guaimía village, Buenaventura, Colombia, a tropical rain forest area. We measured length, width, thickness, mass (n = 1 400), and moisture content of seeds (n = 252). Primary dormancy tests were conducted (n = 200), followed by imbibition (n=252) and germination dynamics, under different conditions of light and temperature specific to understory and forest clearings (n = 300 seeds). Finally, seed storage behavior was established (n = 100 seeds). We observed that size and mass of seeds had a narrow range of values that did not differ within or among fruits and that the species did not exhibit primary dormancy. The seeds are recalcitrant, and recently harvested seeds exhibited higher seed moisture content (ca. 44%) and continuous metabolism. The seed germination percentage was observed to be higher under the specific dense canopy forest light and temperature conditions; furthermore, neither enriched far-red light nor darkness conditions inhibited germination. We concluded that rapid germination could be the establishment strategy of this species. Also, the physiological traits (i.e., rapid germination rate, low germination requirements, absence of primary dormancy, and recalcitrant behavior) and seed size and mass, suggest that A. patinoi is adapted to conditions of mature tropical rain forests.

  6. 21 CFR 212.60 - What requirements apply to the laboratories where I test components, in-process materials, and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... I test components, in-process materials, and finished PET drug products? 212.60 Section 212.60 Food... materials, and finished PET drug products? (a) Testing procedures. Each laboratory used to conduct testing of components, in-process materials, and finished PET drug products must have and follow...

  7. 21 CFR 212.60 - What requirements apply to the laboratories where I test components, in-process materials, and...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Materials. The identity, purity, and quality of reagents, solutions, and supplies used in testing procedures... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS... finished PET drug products? (a) Testing procedures. Each laboratory used to conduct testing of...

  8. 75 FR 47592 - Final Test Guideline; Product Performance of Skin-applied Insect Repellents of Insect and Other...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ..., 2007 (72 FR 32647) (FRL-8135-9), of national experts in which the revisions made in June 2006, were... products in any formulation--such as lotion, liquid, or spray--intended to be applied directly to...

  9. Interaction of microwaves and germinating seeds

    SciTech Connect

    Shafer, F.L.

    1987-01-01

    The preliminary investigation measured the internal metabolic process by ATP production. Leakage of ions and organic material from germinating seeds indicated that membranes are a target of microwaves and heat. Electron photo-micrographs showed an increase in damage to membranes as heat and microwave treatments were increased. The second phase of this investigation was concerned with determining some of the biological activity at the initiation of germination of wheat seed, Triticum aestivum L., using a resonating microwave cavity oscillating at 9.3 GHz as a probe. Direct current conductivity measurements were also made on the seeds as a means of confirming the observations made with the microwave cavity.

  10. Measuring Total and Germinable Spore Populations

    NASA Technical Reports Server (NTRS)

    Noell, A.C.; Yung, P.T.; Yang, W.; Lee, C.; Ponce, A.

    2011-01-01

    It has been shown that bacterial endospores can be enumerated using a microscopy based assay that images the luminescent halos from terbium ions bound to dipicolinic acid, a spore specific chemical marker released upon spore germination. Further development of the instrument has simplified it towards automation while at the same time improving image quality. Enumeration of total spore populations has also been developed allowing measurement of the percentage of viable spores in any population by comparing the germinable/culturable spores to the total. Percentage viability will allow a more quantitative comparison of the ability of spores to survive across a wide range of extreme environments.

  11. Germination of Acacia harpophylla (Brigalow) seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem.

    PubMed

    Arnold, Sven; Kailichova, Yolana; Baumgartl, Thomas

    2014-01-01

    Initial soil water conditions play a critical role when seeding is the primary approach to revegetate post-mining areas. In some semi-arid climates, such as the Brigalow Belt Bioregion in eastern Australia, extensive areas are affected by open-cut mining. Together with erratic rainfall patterns and clayey soils, the Brigalow Belt denotes a unique biome which is representative of other water-limited ecosystems worldwide. Apart from other environmental stressors, germination is governed by the water potential of the surrounding soil material. While previous studies have confirmed the high tolerance of Brigalow (Acacia harpophylla) seeds to a broad range of temperature and salinity, the question of how soil water potential triggers seed germination remains. In this study, we used three replicates of 50 seeds of Brigalow to investigate germination in relation to water potential as an environmental stressor. Solutions of Polyethylene Glycol (PEG 6000) were applied to expose seeds to nine osmotic water potentials ranging from soil water saturation (0 MPa) and field capacity (-.01 to -.03 MPa) to the permanent wilting point (-1.5 MPa). We measured germinability (number of germinated seeds relative to total number of seeds per lot) and mean germination time (mean time required for maximum germination of a seed lot) to quantify germination. Based on the empirical data of the germination we estimated the parameters of the hydrotime model which simulates timing and success of seed emergence. Our findings indicate that Brigalow seeds are remarkably tolerant to water stress, with germination being observed at a water potential as low as -1.5 MPa. Likewise, the average base water potential of a seed population (hydrotime model) was very low and ranged between -1.533 and -1.451 MPa. In general, Brigalow seeds germinate opportunistically over a broad range of abiotic conditions related to temperature, salinity, and water availability. Direct seeding and germination of native

  12. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice.

    PubMed

    Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

    2015-07-01

    Mature dry seeds contain translatable mRNAs called long-lived mRNAs. Early studies have shown that protein synthesis during the initial phase of seed germination occurs from long-lived mRNAs, without de novo transcription. However, the gene expression systems that generate long-lived mRNAs in seeds are not well understood. To examine the accumulation of long-lived mRNAs in developing rice embryos, germination tests using the transcriptional inhibitor actinomycin D (Act D) were performed with the Japonica rice cultivar Nipponbare. Although over 70% of embryos at 10 days after flowering (DAF) germinated in the absence of the inhibitor, germination was remarkably impaired in embryos treated with Act D. In contrast, more than 70% of embryos at 20, 25, 30 and 40 DAF germinated in the presence of Act D. The same results were obtained when another cultivar, Koshihikari, was used, indicating that the long-lived mRNAs required for germination predominantly accumulate in embryos between 10 and 20 DAF during seed development. RNA-Seq identified 529 long-lived mRNA candidates, encoding proteins such as ABA, calcium ion and phospholipid signalling-related proteins, and HSP DNA J, increased from 10 to 20 DAF and were highly abundant in 40 DAF embryos of Nipponbare and Koshihikari. We also revealed that these long-lived mRNA candidates are clearly up-regulated in 10 DAF germinating embryos after imbibition, suggesting that the accumulation of these mRNAs in embryos is indispensable for the induction of germination. The findings presented here may facilitate in overcoming irregular seed germination or producing more vigorous seedlings.

  13. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice

    PubMed Central

    Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

    2015-01-01

    Mature dry seeds contain translatable mRNAs called long-lived mRNAs. Early studies have shown that protein synthesis during the initial phase of seed germination occurs from long-lived mRNAs, without de novo transcription. However, the gene expression systems that generate long-lived mRNAs in seeds are not well understood. To examine the accumulation of long-lived mRNAs in developing rice embryos, germination tests using the transcriptional inhibitor actinomycin D (Act D) were performed with the Japonica rice cultivar Nipponbare. Although over 70% of embryos at 10 days after flowering (DAF) germinated in the absence of the inhibitor, germination was remarkably impaired in embryos treated with Act D. In contrast, more than 70% of embryos at 20, 25, 30 and 40 DAF germinated in the presence of Act D. The same results were obtained when another cultivar, Koshihikari, was used, indicating that the long-lived mRNAs required for germination predominantly accumulate in embryos between 10 and 20 DAF during seed development. RNA-Seq identified 529 long-lived mRNA candidates, encoding proteins such as ABA, calcium ion and phospholipid signalling-related proteins, and HSP DNA J, increased from 10 to 20 DAF and were highly abundant in 40 DAF embryos of Nipponbare and Koshihikari. We also revealed that these long-lived mRNA candidates are clearly up-regulated in 10 DAF germinating embryos after imbibition, suggesting that the accumulation of these mRNAs in embryos is indispensable for the induction of germination. The findings presented here may facilitate in overcoming irregular seed germination or producing more vigorous seedlings. PMID:25941326

  14. Allium cepa chromosome aberration and micronucleus tests applied to study genotoxicity of extracts from pesticide-treated vegetables and grapes.

    PubMed

    Feretti, D; Zerbini, I; Zani, C; Ceretti, E; Moretti, M; Monarca, S

    2007-06-01

    The Allium cepa assay is an efficient test for chemical screening and in situ monitoring for genotoxicity of environmental contaminants. The test has been used widely to study genotoxicity of many pesticides revealing that these compounds can induce chromosomal aberrations in root meristems of A. cepa. Pesticide residues can be present in fruit and vegetables and represent a risk for human health. The mutagenic and carcinogenic action of herbicides, insecticides and fungicides on experimental animals is well known. Several studies have shown that chronic exposure to low levels of pesticides can cause birth defects and that prenatal exposure is associated with carcinogenicity. This study evaluated the potential application of plant genotoxicity tests for monitoring mutagens in edible vegetables. The presence of pesticides and genotoxic compounds extracted from 21 treated vegetables and eight types of grapes sampled from several markets in Campania, a region in Southern Italy, was monitored concurrently. The extracts were analysed for pesticides by gas chromatography and high-performance liquid chromatography, and for genotoxicity using two plant tests: the micronucleus test and the chromosomal aberration test in A. cepa roots. Thirty-three pesticides were detected, some of which are not approved. Genotoxicity was found in some of the vegetables and grapes tested. Allium cepa tests proved to be sensitive in monitoring genotoxicity in food extracts. The micronucleus test in interphase cells gave a much higher mutagenicity than the chromosomal aberration test in anaphase-telophase cells. PMID:17487597

  15. [Ecotoxicity of synthetical musks on wheat (Triticum aestivum) based on seed germination].

    PubMed

    Chen, Su; Sun, Li-na; Sun, Tie-heng; Chao, Lei; Sun, Wei-ke; Lou, Yang

    2011-05-01

    With soil culture the ecotoxicological effects of galaxolide (HHCB) and tonalide (AHTN) on the germination of wheat (Triticum aestivum) seeds were investigated. And the influence of these two synthetical musks on the wheat germination rate, inhibition rate of root elongation and inhibition rate of shoot elongation were studied. The results showed that there were no obvious dose-effect relationship between wheat germination rate and concentrations of these two synthetical musks. Lower dose (HHCB < or = 150 mg x kg(-1), AHTN < or = 200 mg x kg(-1)) could accelerate the germination of wheat. Under the test concentrations of synthetical musks, the wheat germination rates treated with HHCB and AHTN were 77.78%-95.56% and 84.44%-97.78%, respectively. There were good dose-effect relationship between inhibition rate of root elongation (or inhibition rate of shoot elongation) and synthetical musks concentrations. The EC50 of HHCB and AHTN based on shoot were 155.84 mg x kg(-1) and 290.58 mg x kg(-1), and were 215.66 mg x kg(-1) and 323.10 mg x kg(-1) based on root from linear model. The EC50 of wheat sensitive positions showed that the toxicity of HHCB was stronger than AHTN.

  16. Bet-hedging germination of desert annuals: variation among populations and maternal effects in Lepidium lasiocarpum.

    PubMed

    Philippi, T

    1993-09-01

    Prolonged seed dormancy in desert annuals has been modeled as a bet-hedging adaptation to environmental uncertainty. Several aspects of that theory were tested in the preceding article; further results using Lepidium lasiocarpum are reported here. Seeds from different populations of Lepidium differed in their germination behavior. These differences were weakly correlated with differences in the mean winter rainfall among the collection sites: as predicted, sites with greater mean precipitation had less dormancy. Precipitation in the year of seed production was a strong predictor of germination behavior: sites with greater precipitation produced seeds with more dormancy. In a second set of experiments, maternal plant size had a strong effect on germination: plants that produced many seeds had a smaller proportion germinate in the first year. While these results support the general theories of bet-hedging germination in desert annuals, they indicate that selection due to year-to-year variation in population size and sibling competition may be more important in the evolution of seed dormancy than previously thought.

  17. Importance of woody debris in seed germination of Tipularia discolor (Orchidaceae).

    PubMed

    Rasmussen, H; Whigham, D

    1998-06-01

    Concerns about declining populations of terrestrial orchids make it important to identify the environmental factors crucial to seedling recruitment. This study shows that seedlings of Tipularia discolor (cranefly orchid) primarily occur on decomposing wood. Extensive searches of decomposing logs and stumps in mature and successional forests revealed seedlings at 24 sites, of which 15 could be identified as originating from seven different deciduous trees and one conifer. Seeds were planted in natural habitats to test the hypothesis that germination requires decomposing wood. In one experiment, seeds were placed into soil at sites where adult plants were abundant; no germination resulted. In a second experiment, germination of seeds sown in ambient soil was compared with sowings in plots amended with decomposing wood collected from a stump where spontaneous seedlings grew. Germination was much more frequent in plots amended with decomposing wood. We conclude that germination of T. discolor is stimulated in substrates that contain decomposing wood; judging from the occurrence of spontaneous seedlings, wood from at variety of tree species offer a suitable substrate.

  18. Effect of germination on bioactive compounds of soybean (Glycine max)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Germination is the practice of soaking, draining, and keeping seeds until they produce sprouts. The increasing interest in functional and healthy food products has promoted the use of germinated soybean flour in the manufacture of foods for human consumption. It is well known that germination induce...

  19. Phytochemical composition and anticancer activity of germinated wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed germination is a natural method to increase bioactive components that have beneficial effects on human health. Germinated wheat flour samples of a hard red wheat cultivar (Rampart) were prepared after germination of three and five days and investigated for phytochemical composition and anticanc...

  20. Biotransformation of constituents of essential oils by germinating wheat seed.

    PubMed

    Dudai, N; Larkov, O; Putievsky, E; Lerner, H R; Ravid, U; Lewinsohn, E; Mayer, A M

    2000-11-01

    Wheat seeds, when exposed to essential oils, are able to metabolise certain monoterpenes. The actual amounts of the compounds and their derivatives in the endosperm and embryo of wheat seeds, after exposure to the monoterpenes were determined. Neral and geranial, which are the constituents of citral, are reduced and oxidised to the corresponding alcohols and acids. Similarly citronellal, pulegone and carvacrol are converted partly to the corresponding reduction and oxidation products. The aromatic compound vanillin is partly reduced to vanillyl alcohol or oxidised to vanillic acid. In all cases it seems that part of the compounds applied are degraded, as indicated by the inability to account for all the compounds, which were supplied to the germinated seeds. In most cases the derivatives of the essential oil applied were less toxic than the parent compound. The possible role of non-specific enzymes by which the compounds are oxidised or reduced is discussed. PMID:11140596

  1. Development of a superconductor magnetic suspension and balance prototype facility for studying the feasibility of applying this technique to large scale aerodynamic testing

    NASA Technical Reports Server (NTRS)

    Zapata, R. N.; Humphris, R. R.; Henderson, K. C.

    1975-01-01

    The basic research and development work towards proving the feasibility of operating an all-superconductor magnetic suspension and balance device for aerodynamic testing is presented. The feasibility of applying a quasi-six-degree-of freedom free support technique to dynamic stability research was studied along with the design concepts and parameters for applying magnetic suspension techniques to large-scale aerodynamic facilities. A prototype aerodynamic test facility was implemented. Relevant aspects of the development of the prototype facility are described in three sections: (1) design characteristics; (2) operational characteristics; and (3) scaling to larger facilities.

  2. Histochemical studies on protease formation in the cotyledons of germinating bean seeds.

    PubMed

    Yomo, H; Taylor, M P

    1973-03-01

    Protease formation in Phaseolus vulgaris L. cotyledons during seed germination was studied histochemically using a gelatin-film-substrate method. Protease activity can be detected by this method on the 5th day of germination, at approximately the same time that a rapid increase of activity was observed by a test-tube assay with casein as a substrate. At the early stage of germination, protease activity was observed throughout the cotyledon except in two or three cell layers below the cotyledon surface and in several cell layers around the vascular bundles. A highly active cell layer surrounding the protease-inactive cells near the vascular bundles is suggested to be a source of the protease.

  3. Applying Multidimensional Item Response Theory Models in Validating Test Dimensionality: An Example of K-12 Large-Scale Science Assessment

    ERIC Educational Resources Information Center

    Li, Ying; Jiao, Hong; Lissitz, Robert W.

    2012-01-01

    This study investigated the application of multidimensional item response theory (IRT) models to validate test structure and dimensionality. Multiple content areas or domains within a single subject often exist in large-scale achievement tests. Such areas or domains may cause multidimensionality or local item dependence, which both violate the…

  4. The HyPRP gene EARLI1 has an auxiliary role for germinability and early seedling development under low temperature and salt stress conditions in Arabidopsis thaliana.

    PubMed

    Xu, Dan; Huang, Xuan; Xu, Zi-Qin; Schläppi, Michael

    2011-09-01

    The effect of the hybrid proline-rich protein (HyPRP) gene EARLI1 on the rate of germination (germinability) of Arabidopsis seeds and seedling growth under low temperature and salt stress conditions was investigated. EARLI1 was induced during germination in embryonic tissues, and was strongly expressed in certain parts of young seedlings. Comparisons of control, overexpressing (OX), and knockout (KO) lines indicated that higher than wild type levels of EARLI1 improved germinability, root elongation, and reduction of sodium accumulation in leaves under salt stress, as well as germinability under low-temperature stress. Abscisic acid (ABA) contents were relatively low after prolonged salt stress, suggesting that EARLI1 has an ABA-independent effect on germinability under these conditions. Overexpression of EARLI1 during germination enhanced the sensitivity of seeds to exogenously applied ABA, suggesting that EARLI1 has an ABA-dependent negative effect on seed germinability under high ABA stress conditions. Well-known stress response marker genes such as COR15a, KIN1, P5SC1, and RD29 were unaffected whereas P5SC2, RD22, or RAB18 were only slightly affected in OX and KO plants. The pleiotropic effects of EARLI1 during stress and an absence of strong regulatory effects on stress marker genes suggest that this HyPRP gene has an auxiliary role for various stress protection responses in Arabidopsis.

  5. Hydration, sporoderm breaking and germination of Cupressus arizonica pollen.

    PubMed

    Chichiriccò, G; Spanò, L; Torraca, G; Tartarini, A

    2009-05-01

    In vitro and in vivo rehydration and germination in Cupressus arizonica pollen were examined using light and scanning electron microscopy. Shed pollen has 12.6% water content, which reduced to 8.2% after dispersal, and this latter pollen survived for some months at room temperature and for years at -10 degrees C. Rehydration requires breaking of the sporoderm walls and depends on the composition and pH of the rehydration medium. Acidity restrains the breakage, while alkalinity promotes it. Pollen division follows exine shedding and requires the persistence of the mucilaginous layer; hence, pH values countering these outcomes prevent division. Division results in a large and a small cell separated by a callosic wall. A pollen tube develops from the innermost intine of the large cell, which is callosic, and extends into the mucilaginous middle intine. The percentage germination never exceeded 17% in all tested media. In vivo, pollen rehydrates and casts off the exine in the micropylar drop. Drop withdrawal brings pollen to the apical nucellar cells that degenerate in the meantime, and it leaves a deposit on the surface of the micropylar canal. After contaction of the nucellar cells, the pollen flattens and its mucilaginous layer shrinks and disappears. This occurs simultaneously with sealing of the micropylar canal. During this time, pollen divides asymmetrically without the callosic wall, and the larger cell develops a tube in the interface with the nucellus. Only some pollen grains accomplish adhesion to the nucellus and germinate. The in vitro and in vivo developmental stages are discussed. PMID:19470107

  6. Magnetic Test Performance Capabilities at the Goddard Space Flight Center as Applied to the Global Geospace Science Initiative

    NASA Technical Reports Server (NTRS)

    Mitchell, Darryl R.

    1997-01-01

    Goddard Space Flight Center's (GSFC) Spacecraft Magnetic Test Facility (SMTF) is a historic test facility that has set the standard for all subsequent magnetic test facilities. The SMTF was constructed in the early 1960's for the purpose of simulating geomagnetic and interplanetary magnetic fields. Additionally, the facility provides the capability for measuring spacecraft generated magnetic fields as well as calibrating magnetic attitude control systems and science magnetometers. The SMTF was designed for large, spacecraft level tests and is currently the second largest spherical coil system in the world. The SMTF is a three-axis Braunbek system composed of four coils on each of three orthogonal axes. The largest coils are 12.7 meters (41.6 feet) in diameter. The three-axis Braunbek configuration provides a highly uniform cancellation of the geomagnetic field over the central 1.8 meter (6 foot) diameter primary test volume. Cancellation of the local geomagnetic field is to within +/-0.2 nanotesla with a uniformity of up to 0.001% within the 1.8 meter (6 foot) diameter primary test volume. Artificial magnetic field vectors from 0-60,000 nanotesla can be generated along any axis with a 0.1 nanotesla resolution. Oscillating or rotating field vectors can also be produced about any axis with a frequency of up to 100 radians/second. Since becoming fully operational in July of 1967, the SMTF has been the site of numerous spacecraft magnetics tests. Spacecraft tested at the SMTF include: the Solar Maximum Mission (SMM), Magsat, LANDSAT-D, the Fast Aurora] Snapshot (FAST) Explorer and the Sub-millimeter-Wave-Astronomy Satellite (SWAS) among others. This paper describes the methodology and sequencing used for the Global Geospace Science (GGS) initiative magnetic testing program in the Goddard Space Flight Center's SMTF. The GGS initiative provides an exemplary model of a strict and comprehensive magnetic control program.

  7. Temperature Regulation of Germination in Crimson Clover Seeds 1

    PubMed Central

    Ching, Te May

    1975-01-01

    Seeds of Dixie crimson clover (Trifolium incarnatum cv. Dixie) completed germination in 36 hours at 20 C. At 10 C germination was delayed by 24 hours. At 30 C only 20% germinated and the rest remained viable for a long time but not germinable. Different patterns of adenylate energy state and zymograms of acid phosphatase and esterase were observed from seeds grown under the three temperatures for 24 hours. Varied specific activities of protease, α-amylase, ATPase, RNase, acid phosphatase, glutamine synthetase, and fumarase were also found. Protein-synthesizing ability was proportional to temperature. These data indicate that temperature regulates seed germination at multiple sites. PMID:16659391

  8. Smoke-induced seed germination in California chaparral

    USGS Publications Warehouse

    Keeley, J.E.; Fotheringham, C.J.

    1998-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here we report that smoke also induces germination in these same species. Smoke is highly effective, often inducing 100% germination in deeply dormant seed populations with 0% control germination. Smoke induces germination both directly and indirectly by aqueous or gaseous transfer from soil to seeds. Neither nitrate nor ammonium ions were effective in stimulating germination of smoke-stimulated species, nor were most of the quantitatively important gases generated by biomass smoke. Nitrogen dioxide, however, was very effective at inducing germination in Caulanthus heterophyllus (Brassicaceae), Emmenanthe penduliflora (Hydrophyllaceae), Phacelia grandiflora (Hydrophyllaceae), and Silene multinervia (Caryophyllaceae). Three species, Dendromecon rigida (Papaveraceae), Dicentra chrysantha, and Trichostema lanatum (Lamiaceae), failed to germinate unless smoke treatment was coupled with prior treatment of 1 yr soil storage. Smoke-stimulated germination was found in 25 chaparral species, representing 11 families, none of which were families known for heat-shock-stimulated germination. Seeds of smoke-stimulated species have many analogous characteristics that separate them from most heat-shock-stimulated seeds, including: (1) outer seed coats that are highly textured, (2) a poorly developed outer cuticle, (3) absence of a dense palisade tissue in the seed coat, and (4) a subdermal membrane that is semipermeable, allowing water passage but blocking entry of large (molecular mass > 500) solutes. Tentative evidence suggests that permeability characteristics of this subdermal layer are altered by

  9. [Salt tolerance evaluation of cotton (Gossypium hirsutum) at its germinating and seedling stages and selection of related indices].

    PubMed

    Zhang, Guo-wei; Lu, Hai-ling; Zhang, Lei; Chen, Bing-lin; Zhou, Zhi-guo

    2011-08-01

    A sand culture experiment was conducted to study the salt tolerance of 13 cotton cultivars at their germinating and seedling stages under the stress of different concentration NaCl, and a cluster analysis was made on the salt tolerance, according to the subjection values of salt toxicity coefficients of multi-indices and the sum subjection value. It was observed that the appropriate concentration of NaCl for the evaluation of salt tolerance was 150 mmol x L(-1). The salt tolerance differed with cultivar and growth stage. Among the 13 cultivars, the CCRI-44 and CCRI-177 were steadily salt-tolerant at both germinating and seedling stages, the CCRI-103, Dexiamian 1, and NuCOTN 33B were steadily and moderately salt-tolerant, while the CCRI-102, Sumian 12, and Simian 3 were steadily salt-sensitive. Germination rate, germination potential, germination index, vigor index, and fresh mass could be served as the indicators to evaluate the salt tolerance of the cultivars at germinating stage, while plant height, leaf expansion rate, shoot dry mass, root dry mass, root vigor, and net photosynthetic rate could be applied to assess the salt tolerance at seedling stage.

  10. Applying Flammability Limit Probabilities and the Normoxic Upward Limiting Pressure Concept to NASA STD-6001 Test 1

    NASA Technical Reports Server (NTRS)

    Olson, Sandra L.; Beeson, Harold; Fernandez-Pello, A. Carlos

    2014-01-01

    Repeated Test 1 extinction tests near the upward flammability limit are expected to follow a Poisson process trend. This Poisson process trend suggests that rather than define a ULOI and MOC (which requires two limits to be determined), it might be better to define a single upward limit as being where 1/e (where e (approx. equal to 2.7183) is the characteristic time of the normalized Poisson process) of the materials burn, or, rounding, where approximately 1/3 of the samples fail the test (and burn). Recognizing that spacecraft atmospheres will not bound the entire oxygen-pressure parameter space, but actually lie along the normoxic atmosphere control band, we can focus the materials flammability testing along this normoxic band. A Normoxic Upward Limiting Pressure (NULP) is defined that determines the minimum safe total pressure for a material within the constant partial pressure control band. Then, increasing this pressure limit by a factor of safety, we can define the material as being safe to use at the NULP + SF (where SF is on the order of 10 kilopascal, based on existing flammability data). It is recommended that the thickest material to be tested with the current Test 1 igniter should be 3 mm thick (1/8 inches) to avoid the problem of differentiating between an ignition limit and a true flammability limit.

  11. Paper-and-Pencil and Web-Based Testing: The Measurement Invariance of the Big Five Personality Tests in Applied Settings

    ERIC Educational Resources Information Center

    Vecchione, Michele; Alessandri, Guido; Barbaranelli, Claudio

    2012-01-01

    This study investigates the measurement equivalence of a five-factor measure of personality across two groups applying for jobs, who completed the same questionnaire using either a paper-and-pencil (n = 429) or a web online answer format (n = 651). The data were collected using the Big Five Questionnaire-2 (BFQ-2; which is a measure of the Five…

  12. [Germination strategy and ecological adaptability of Eragrostis pilosa].

    PubMed

    Li, Xuehua; Li, Xiaola; Jiang, Deming; Liu, Zhimin

    2006-04-01

    The study on the germination strategy of Eragrostis pilosa under different storage and environmental conditions showed that freshly collected E. pilosa seeds had a stronger innate dormancy. Chilling and dry storage for 4 months had no obvious effect on releasing from dormancy, while longer time storage could facilitate seed maturation. The seeds could germinate either in light or in darkness, and stronger light was in favor of germination. The optimal temperature for germination was 28 degrees C, while higher or lower temperature could result in the decrease of germination. The germination percentage of seeds under changed temperature (16 to 28 degrees C) was higher than that under constant temperature (28 degrees C), but with no significant difference. The critical amount of rain for seed germination was about 10 mm, and the germination percentage and duration all increased with increasing rainfall. E. pilosa had two germination strategies, i. e., quick germination and dormancy for more than one year. Based on the seed morphological characters and germination strategies, it could be concluded that E. pilosa had a persistent soil seed bank.

  13. Requirements for In Vitro Germination of Paenibacillus larvae Spores

    PubMed Central

    Alvarado, Israel; Phui, Andy; Elekonich, Michelle M.

    2013-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a disease affecting honey bee larvae. First- and second-instar larvae become infected when they ingest food contaminated with P. larvae spores. The spores then germinate into vegetative cells that proliferate in the midgut of the honey bee. Although AFB affects honey bees only in the larval stage, P. larvae spores can be distributed throughout the hive. Because spore germination is critical for AFB establishment, we analyzed the requirements for P. larvae spore germination in vitro. We found that P. larvae spores germinated only in response to l-tyrosine plus uric acid under physiologic pH and temperature conditions. This suggests that the simultaneous presence of these signals is necessary for spore germination in vivo. Furthermore, the germination profiles of environmentally derived spores were identical to those of spores from a biochemically typed strain. Because l-tyrosine and uric acid are the only required germinants in vitro, we screened amino acid and purine analogs for their ability to act as antagonists of P. larvae spore germination. Indole and phenol, the side chains of tyrosine and tryptophan, strongly inhibited P. larvae spore germination. Methylation of the N-1 (but not the C-3) position of indole eliminated its ability to inhibit germination. Identification of the activators and inhibitors of P. larvae spore germination provides a basis for developing new tools to control AFB. PMID:23264573

  14. Similarity analysis applied to the design of scaled tests of hydraulic mitigation methods for Tank 241-SY-101

    SciTech Connect

    Liljegren, L.M.

    1993-02-01

    The episodic gas releases from Tank 241-SY-101 (SY-101) pose a potential safety hazard. It is thought that gas releases occur because gases are generated and trapped in layers of settled solids located at the bottom of the tank. This document focuses on issues associated with testing of hydraulic mitigation technologies proposed for SY-101. The basic assumption underlying the concept of hydraulic mitigation is that mobilization or maintained suspension of the solids settled in the bottom of the tank wig prevent gas accumulation. Engineering of hydraulic technologies will require testing to determine the operating parameters required to mobilize the solids and to maintain these solids in suspension. Because full scale testing is extremely expensive (even when possible), scaled tests are needed to assess the merit of the proposed technologies and to provide data for numerical or analytical modeling. This research is conducted to support testing and evaluation of proposed hydraulic mitigation concepts only. The work here is oriented towards determining the jet velocities, nozzle sizes, and other operating parameters required to mobilize the settled solids in SY- 101 and maintain them in suspension.

  15. An experimental and analytical investigation of the rail shear-test method as applied to composite materials

    NASA Technical Reports Server (NTRS)

    Garcia, R.; Mcwithey, R. R.; Weisshaar, T. A.

    1979-01-01

    This report presents the results from an experimental and analytical investigation of the stress distributions occurring in a rail shear test. The effects of non-uniform stresses induced by differential thermal expansion, rail flexibility and specimen aspect ratio on measured shear modulus and ultimate strength of composite laminates are shown. A two-dimensional linearly elastic finite element model was used to analytically determine how various geometric parameters influenced the magnitude and distribution of inplane normal and shear stresses in a tensile rail shear specimen. Rail shear tests were conducted at room temperature and 589 K (600 F) on selected graphite-polyimide composite laminates using two titanium rail configurations. The analysis and test methods are discussed, and the results of the effects of the various parameters on shear modulus and ultimate strength are presented.

  16. Bayesian meta-analysis of test accuracy in the absence of a perfect reference test applied to bone scintigraphy for the diagnosis of complex regional pain syndrome.

    PubMed

    Held, Ulrike; Brunner, Florian; Steurer, Johann; Wertli, Maria M

    2015-11-01

    There is conflicting evidence about the accuracy of bone scintigraphy (BS) for the diagnosis of complex regional pain syndrome 1 (CRPS 1). In a meta-analysis of diagnostic studies, the evaluation of test accuracy is impeded by the use of different imperfect reference tests. The aim of our study is to summarize sensitivity and specificity of BS for CRPS 1 and to identify factors to explain heterogeneity. We use a hierarchical Bayesian approach to model test accuracy and threshold, and we present different models accounting for the imperfect nature of the reference tests, and assuming conditional dependence between BS and the reference test results. Further, we include disease duration as explanatory variable in the model. The models are compared using summary ROC curves and the deviance information criterion (DIC). Our results show that those models which account for different imperfect reference tests with conditional dependence and inclusion of the covariate are the ones with the smallest DIC. The sensitivity of BS was 0.87 (95% credible interval 0.73-0.97) and the overall specificity was 0.87 (0.73-0.95) in the model with the smallest DIC, in which missing values of the covariate are imputed within the Bayesian framework. The estimated effect of duration of symptoms on the threshold parameter was 0.17 (-0.25 to 0.57). We demonstrate that the Bayesian models presented in this paper are useful to address typical problems occurring in meta-analysis of diagnostic studies, including conditional dependence between index test and reference test, as well as missing values in the study-specific covariates. PMID:26479506

  17. New error calibration tests for gravity models using subset solutions and independent data - Applied to GEM-T3

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Nerem, R. S.; Chinn, D. S.; Chan, J. C.; Patel, G. B.; Klosko, S. M.

    1993-01-01

    A new method has been developed to provide a direct test of the error calibrations of gravity models based on actual satellite observations. The basic approach projects the error estimates of the gravity model parameters onto satellite observations, and the results of these projections are then compared with data residual computed from the orbital fits. To allow specific testing of the gravity error calibrations, subset solutions are computed based on the data set and data weighting of the gravity model. The approach is demonstrated using GEM-T3 to show that the gravity error estimates are well calibrated and that reliable predictions of orbit accuracies can be achieved for independent orbits.

  18. Differential activity of Striga hermonthica seed germination stimulants and Gigaspora rosea hyphal branching factors in rice and their contribution to underground communication.

    PubMed

    Cardoso, Catarina; Charnikhova, Tatsiana; Jamil, Muhammad; Delaux, Pierre-Marc; Verstappen, Francel; Amini, Maryam; Lauressergues, Dominique; Ruyter-Spira, Carolien; Bouwmeester, Harro

    2014-01-01

    Strigolactones (SLs) trigger germination of parasitic plant seeds and hyphal branching of symbiotic arbuscular mycorrhizal (AM) fungi. There is extensive structural variation in SLs and plants usually produce blends of different SLs. The structural variation among natural SLs has been shown to impact their biological activity as hyphal branching and parasitic plant seed germination stimulants. In this study, rice root exudates were fractioned by HPLC. The resulting fractions were analyzed by MRM-LC-MS to investigate the presence of SLs and tested using bioassays to assess their Striga hermonthica seed germination and Gigaspora rosea hyphal branching stimulatory activities. A substantial number of active fractions were revealed often with very different effect on seed germination and hyphal branching. Fractions containing (-)-orobanchol and ent-2'-epi-5-deoxystrigol contributed little to the induction of S. hermonthica seed germination but strongly stimulated AM fungal hyphal branching. Three SLs in one fraction, putative methoxy-5-deoxystrigol isomers, had moderate seed germination and hyphal branching inducing activity. Two fractions contained strong germination stimulants but displayed only modest hyphal branching activity. We provide evidence that these stimulants are likely SLs although no SL-representative masses could be detected using MRM-LC-MS. Our results show that seed germination and hyphal branching are induced to very different extents by the various SLs (or other stimulants) present in rice root exudates. We propose that the development of rice varieties with different SL composition is a promising strategy to reduce parasitic plant infestation while maintaining symbiosis with AM fungi.

  19. Applied Cognition: Testing the Effects of Independent Silent Reading on Secondary Students' Achievement and Attribution

    ERIC Educational Resources Information Center

    Cuevas, Joshua A.; Irving, Miles A.; Russell, L. Roxanne

    2014-01-01

    This study implemented an independent silent reading (ISR) program with 145 10th grade students. Students were measured on total reading ability, vocabulary, reading comprehension, a state-mandated high stakes end-of-course test (EOCT), and reading attribution. After controlling for initial skill and disposition levels, the results indicated that…

  20. Controlling Guessing Bias in the Dichotomous Rasch Model Applied to a Large-Scale, Vertically Scaled Testing Program

    ERIC Educational Resources Information Center

    Andrich, David; Marais, Ida; Humphry, Stephen Mark

    2016-01-01

    Recent research has shown how the statistical bias in Rasch model difficulty estimates induced by guessing in multiple-choice items can be eliminated. Using vertical scaling of a high-profile national reading test, it is shown that the dominant effect of removing such bias is a nonlinear change in the unit of scale across the continuum. The…

  1. 40 CFR 86.1901 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86... diesel heavy-duty engines above 8,500 lbs. GVWR that are subject to engine-based exhaust emission... engines that have gone into service? 86.1901 Section 86.1901 Protection of Environment...

  2. 40 CFR 86.1901 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86... diesel heavy-duty engines above 8,500 lbs. GVWR that are subject to engine-based exhaust emission... engines that have gone into service? 86.1901 Section 86.1901 Protection of Environment...

  3. 40 CFR 86.1901 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86... diesel heavy-duty engines above 8,500 lbs. GVWR that are subject to engine-based exhaust emission... engines that have gone into service? 86.1901 Section 86.1901 Protection of Environment...

  4. 40 CFR 86.1901 - What testing requirements apply to my engines that have gone into service?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86... diesel heavy-duty engines above 8500 lbs. GVWR that are subject to engine-based exhaust emission... engines that have gone into service? 86.1901 Section 86.1901 Protection of Environment...

  5. 21 CFR 212.60 - What requirements apply to the laboratories where I test components, in-process materials, and...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., strength, quality, and purity. (c) Analytical methods. Laboratory analytical methods must be suitable for...) Materials. The identity, purity, and quality of reagents, solutions, and supplies used in testing procedures must be adequately controlled. All solutions that you prepare must be properly labeled to show...

  6. 21 CFR 212.60 - What requirements apply to the laboratories where I test components, in-process materials, and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., strength, quality, and purity. (c) Analytical methods. Laboratory analytical methods must be suitable for...) Materials. The identity, purity, and quality of reagents, solutions, and supplies used in testing procedures must be adequately controlled. All solutions that you prepare must be properly labeled to show...

  7. 21 CFR 212.60 - What requirements apply to the laboratories where I test components, in-process materials, and...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., strength, quality, and purity. (c) Analytical methods. Laboratory analytical methods must be suitable for...) Materials. The identity, purity, and quality of reagents, solutions, and supplies used in testing procedures must be adequately controlled. All solutions that you prepare must be properly labeled to show...

  8. 40 CFR 80.583 - What alternative sampling and testing requirements apply to importers who transport motor vehicle...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diesel fuel, or ECA marine fuel by truck or rail car? Importers who import diesel fuel subject to the 15... rail car for import to the U.S., the importer must obtain a copy of the terminal test result that... diesel fuel samples and perform audits. These inspections or audits may be either announced...

  9. Evaluation of constraint methodologies applied to a shallow-flaw cruciform bend specimen tested under biaxial loading conditions

    SciTech Connect

    Bass, B.R.; McAfee, W.J.; Williams, P.T.; Pennell, W.E.

    1998-01-01

    A technology to determine shallow-flaw fracture toughness of reactor pressure vessel (RPV) steels is being developed for application to the safety assessment of RPVs containing postulated shallow surface flaws. Matrices of cruciform beam tests were developed to investigate and quantify the effects of temperature, biaxial loading, and specimen size on fracture initiation toughness of two-dimensional (constant depth), shallow surface flaws. The cruciform beam specimens were developed at Oak Ridge National Laboratory (ORNL) to introduce a prototypic, far-field. out-of-plane biaxial stress component in the test section that approximates the nonlinear stresses resulting from pressurized-thermal-shock or pressure-temperature loading of an RPV. Tests were conducted under biaxial load ratios ranging from uniaxial to equibiaxial. These tests demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower transition temperature region for RPV materials. The cruciform fracture toughness data were used to evaluate fracture methodologies for predicting the observed effects of biaxial loading on shallow-flaw fracture toughness. Initial emphasis was placed on assessment of stress-based methodologies. namely, the J-Q formulation, the Dodds-Anderson toughness scaling model, and the Weibull approach. Applications of these methodologies based on the hydrostatic stress fracture criterion indicated an effect of loading-biaxiality on fracture toughness, the conventional maximum principal stress criterion indicated no effect.

  10. A psychometric analysis of the reading the mind in the eyes test: toward a brief form for research and applied settings

    PubMed Central

    Olderbak, Sally; Wilhelm, Oliver; Olaru, Gabriel; Geiger, Mattis; Brenneman, Meghan W.; Roberts, Richard D.

    2015-01-01

    The Reading the Mind in the Eyes Test is a popular measure of individual differences in Theory of Mind that is often applied in the assessment of particular clinical populations (primarily, individuals on the autism spectrum). However, little is known about the test's psychometric properties, including factor structure, internal consistency, and convergent validity evidence. We present a psychometric analysis of the test followed by an evaluation of other empirically proposed and statistically identified structures. We identified, and cross-validated in a second sample, an adequate short-form solution that is homogeneous with adequate internal consistency, and is moderately related to Cognitive Empathy, Emotion Perception, and strongly related to Vocabulary. We recommend the use of this short-form solution in normal adults as a more precise measure over the original version. Future revisions of the test should seek to reduce the test's reliance on one's vocabulary and evaluate the short-form structure in clinical populations. PMID:26500578

  11. Morpho-anatomy, imbibition, viability and germination of the seed of Anadenanthera colubrina var. cebil (Fabaceae).

    PubMed

    Varela, Rodolfo Omar; Albornoz, Patricia Liliana

    2013-09-01

    Seed biology is a relevant aspect of tropical forests because it is central to the understanding of processes of plant establishment, succession and natural regeneration. Anadenanthera colubrina var. cebil is a timber tree from South America that produces large seeds with thin weak teguments, which is uncommon among legumes. This study describes the morphology and anatomy of the seed coat, the viability, imbibition, and germination in this species. Seeds used during the essays came from 10 trees that grow naturally in Horco Molle, province of Tucumán, Argentina. Seed morphology was described from a sample of 20 units. The seed coat surface was examined with a scanning electron microscope. Transverse sections of hydrated and non-hydrated seeds were employed to describe the histological structure of the seed coat. Hydration, viability and germination experiments were performed under laboratory controlled conditions; and the experimental design consisted of 10 replicas of 10 seeds each. Viability and germination tests were conducted using freshly fallen seeds and seeds stored for five months. Morphologically the seeds of A. colubrina var. cebil are circular to subcircular, laterally compressed, smooth, bright brown and have a horseshoe fissure line (= pleurogram) on both sides. The seed coat comprises five tissue layers and a double (external and internal) cuticle. The outer cuticle (on the epidermis) is smooth and interrupted by microcracks and pores of variable depth. The epidermis consists of macroesclereids with non-lignified secondary walls. This layer is separated from the underlying ones during seed hydration. The other layers of internal tissues are comprised of osteosclereids, parenchyma, osteosclereids, and macrosclereids. The percentage of viable seeds was 93%, decreasing to 75% in seeds with five months old. Seed mass increased 76% after the first eight hours of hydration. Germination percentage was 75% after 76 hours. Germination of seeds stored for five

  12. Effect of Pb, Cd, Hg, As, and Cr on germination and root growth of Sinapis alba seeds

    SciTech Connect

    Fargasova, A. )

    1994-03-01

    Heavy metals have been widely recognized as highly toxic and dangerous. Plants, algae and bacteria respond to heavy metal toxicity by inducing different enzymes, creating ion influx/efflux for ionic balance and synthesizing small peptides. These peptides bind metal ions and reduce toxicity. Metals come from the natural weathering processes of the earth's crust, industrial discharge, pest or disease control agents applied to plants, urban run-off, mining, soil erosion, sewage effluents, air pollution fallout and other sources. Plants can be affected directly by air pollutants, as well as indirectly through the contamination of soil and water. At the same time, plant is a member of the food chain and may create a risk for man and animals through contamination of food supplies. In recent years a considerable progress has been made in the assay of trace elements in environmental plant samples. For higher plants, the accumulation of metals, especially cadmium, was tested when plants grew on sewage sludge-amended soils or in soils of cadmium residues from phosphate fertilizers. No reports were accessible to us on the direct effect of tested metals (Pb, Hg, Cr, As, Cd) on seed germination and root growth. The paucity of literature initiated our present work. In this study, an attempt has been made to investigate the acute toxicity of five metals (Cr[sup 6+], Cd[sup 2+], Hg[sup 2+], Pb[sup 2+], As[sup 5+]) which are widely spread in the environment and are widely recognized as highly toxic and dangerous. As the testing subject, mustard seeds (Sinapis alba) were used and their germination and root growth were observed. 12 refs., 1 tab.

  13. Phytotoxicity of nanoparticles: inhibition of seed germination and root growth.

    PubMed

    Lin, Daohui; Xing, Baoshan

    2007-11-01

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC50) of nano-Zn and nano-ZnO were estimated to be near 50mg/L for radish, and about 20mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles.

  14. Sensitivity of spore germination and germ tube elongation of Saccharina japonica to metal exposure.

    PubMed

    Han, Taejun; Kong, Jeong-Ae; Kang, Hee-Gyu; Kim, Seon-Jin; Jin, Gyo-Sun; Choi, Hoon; Brown, Murray T

    2011-11-01

    The sensitivity of early life stages of the brown seaweed Saccharina japonica to six metals (Cd, Cu, Hg, Ni, Pb, Zn) and two waste-water samples were investigated and a new toxicity bioassay developed. The two endpoints used were spore germination and germ tube elongation with an exposure time of 24 h. Optimal test conditions determined for photon irradiance, pH, salinity and temperature were darkness, pH 8, 35‰ and 15°C, respectively. The toxicity ranking of five metals was: Hg (EC(50) of 41 and 42 μg l(-1)) > Cu (120 and 81 μg l(-1)) > Ni (2,009 and 1,360 μg l(-1)) > Zn (3,024 and 3,897 μg l(-1)) > Pb (4,760 and 4,429 μg l(-1)) > Cd (15,052 and 7,541 μg l(-1)) for germination and germ tube elongation, respectively. The sensitivities to Cd, Cu and Ni were greater in germ tube elongation than in germination process. When tested against two different waste-water samples (processed animal and printed circuit board waste-water) values of EC(50) were between 21.29 and 32.02% for germination and between 5.33 and 8.98% for germ tube elongation. Despite differences in their chemical composition, the toxic effects of waste-water samples, as indicated by EC(50) values, did not differ significantly for the same endpoints. The CV range for both germination and germ tube elongation was between 4.61 and 37.69%, indicating high levels of precision of the tests. The results compare favourably with those from more established test procedures employing micro- and macroalgae. The advantages and potential limitations of the bioassay for the assessment of anthropogenic impacts on coastal ecosystems and commercial cultivation areas in near-shore environments are discussed.

  15. [Effects of simulated acid rain on seed germination and seedling growth of different type corn Zea mays].

    PubMed

    Zhang, Hai-Yan

    2013-06-01

    Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.

  16. Seed viability and germination success of Acacia tortilis along land-use and aridity gradients in the Eastern Sahara.

    PubMed

    Andersen, Gidske Leknæs; Krzywinski, Knut; Gjessing, Håkon K; Pierce, Richard Holton

    2016-01-01

    Our study focuses on the keystone species Acacia tortilis and is the first to investigate the effect of domestic ungulates and aridity on seed viability and germination over an extensive part of the Eastern Sahara. Bruchids infest its seeds and reduce their viability and germination, but ingestion by ruminant herbivores diminishes infestation levels and enhances/promotes seed viability and germination. The degree of these effects seems to be correlated with animal body mass. Significantly reduced numbers of wild ruminant ungulates have increased the potential importance of domestic animals and pastoral nomadism for the functionality of arid North African and Middle Eastern ecosystems. We sampled seeds (16,543) from A. tortilis in eight areas in three regions with different aridity and land use. We tested the effect of geography and sampling context on seed infestation using random effects logistic regressions. We did a randomized and balanced germination experiment including 1193 seeds, treated with different manure. Germination time and rates across geography, sampling context, and infestation status were analyzed using time-to-event analyses, Kaplan-Meier curves and proportional hazards Cox regressions. Bruchid infestation is very high (80%), and the effects of context are significant. Neither partial infestation nor adding manure had a positive effect on germination. There is a strong indication that intact, uningested seeds from acacia populations in the extremely arid Western Desert germinate more slowly and have a higher fraction of hard seeds than in the Eastern Desert and the Red Sea Hills. For ingested seeds in the pastoralist areas we find that intact seeds from goat dung germinate significantly better than those from camel dung. This is contrary to the expected body-mass effect. There is no effect of site or variation in tribal management.

  17. [Effects of simulated acid rain on seed germination and seedling growth of different type corn Zea mays].

    PubMed

    Zhang, Hai-Yan

    2013-06-01

    Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area. PMID:24066549

  18. Seed viability and germination success of Acacia tortilis along land-use and aridity gradients in the Eastern Sahara.

    PubMed

    Andersen, Gidske Leknæs; Krzywinski, Knut; Gjessing, Håkon K; Pierce, Richard Holton

    2016-01-01

    Our study focuses on the keystone species Acacia tortilis and is the first to investigate the effect of domestic ungulates and aridity on seed viability and germination over an extensive part of the Eastern Sahara. Bruchids infest its seeds and reduce their viability and germination, but ingestion by ruminant herbivores diminishes infestation levels and enhances/promotes seed viability and germination. The degree of these effects seems to be correlated with animal body mass. Significantly reduced numbers of wild ruminant ungulates have increased the potential importance of domestic animals and pastoral nomadism for the functionality of arid North African and Middle Eastern ecosystems. We sampled seeds (16,543) from A. tortilis in eight areas in three regions with different aridity and land use. We tested the effect of geography and sampling context on seed infestation using random effects logistic regressions. We did a randomized and balanced germination experiment including 1193 seeds, treated with different manure. Germination time and rates across geography, sampling context, and infestation status were analyzed using time-to-event analyses, Kaplan-Meier curves and proportional hazards Cox regressions. Bruchid infestation is very high (80%), and the effects of context are significant. Neither partial infestation nor adding manure had a positive effect on germination. There is a strong indication that intact, uningested seeds from acacia populations in the extremely arid Western Desert germinate more slowly and have a higher fraction of hard seeds than in the Eastern Desert and the Red Sea Hills. For ingested seeds in the pastoralist areas we find that intact seeds from goat dung germinate significantly better than those from camel dung. This is contrary to the expected body-mass effect. There is no effect of site or variation in tribal management. PMID:26811790

  19. A combination of a SEM technique and X-ray microanalysis for studying the spore germination process of Clostridium tyrobutyricum.

    PubMed

    Bassi, Daniela; Cappa, Fabrizio; Cocconcelli, Pier Sandro

    2009-06-01

    Clostridium tyrobutyricum is an anaerobic bacterium responsible for late blowing defects during cheese ripening and it is of scientific interest for biological hydrogen production. A scanning electron microscopy (SEM) coating technique and X-ray microanalysis were developed to analyze the architecture and chemical composition of spores upon germination in response to environmental changes. In addition, we investigated the effects of different compounds on this process. Agents and environmental conditions inducing germination were characterized monitoring changes in optical density (OD). Among all tested conditions, the greatest drop in OD(625) (57.4%) was obtained when spores were incubated in l-alanine/l-lactate buffer, pH 4.6. In addition, a carbon-coating SEM technique and X-ray microanalysis were used to observe the architecture of spores and to examine calcium dipicolinate release. Conditions inducing C. tyrobutyricum spore germination were identified and SEM X-ray microanalysis clearly distinguished germinating from dormant spores. We confirmed that calcium dipicolinate release is one of the first events occurring. These microscopy methods could be considered sensitive tools for evaluating morphological and chemical changes in spores of C. tyrobutyricum during the initial phase of germination. Information gathered from this work may provide new data for further research on germination.

  20. Role of charred wood, heat-shock, and light in germination of postfire phrygana species from the Eastern Mediterranean Basin

    USGS Publications Warehouse

    Keeley, J.E.; Baer-Keeley, M.

    1999-01-01

    Seeds of 22 species collected from recently burned phrygana were tested for their response to fire-type cues of charred wood and heat-shock. All Cistus species were stimulated by brief heat-shock, as shown in previous studies; however, none responded to charred wood. Only one of the 22 species was stimulated by charred wood, and only in dark-inhibited seeds, and this response did not occur in the light. The lack of charred-wood-induced germination is in contrast to the substantial proportion of species with this germination response reported for mediterranean-type vegetation in California, the Cape region of South Africa, and Western Australia. Phrygana has many species with heat-shock-stimulated germination, primarily in the Fabaceae and Cistaceae. This germination cue is widespread in these two families, thus, the presence of heat-shock-stimulated germination is a result of homologous, rather than covergent, adaptations in mediterranean-climate ecosystems. Germination response to light was not randomly distributed with respect to fire-type response. Heat-shock-stimulated species were almost uniformly light neutral, in contrast to more opportunistic colonizing species with non-refractory seeds, in which half of the species responded positively or negatively to light.

  1. Effects of simulated acid rain on the pollen germination and pollen tube growth of apple (Malus sylvestris Miller cv. Golden).

    PubMed

    Munzuroglu, O; Obek, E; Geckil, H

    2003-01-01

    The pollens of apple flowers have been treated with simulated acid rain solutions in range of pHs 2.9 to 5.0 in order to determine the threshold proportion values that lead the observed symptoms of detriments of acid rain. Compared to controls (pH 6.5), pollen germination decreased by 41.75% at pH 3.3 and pollen tube elongation decreased by 24.3% at pH 3.4. Acid rain threshold proportion value was around pH 3.3 and 3.4 for apple pollen germination and pollen tube elongation, respectively. Furthermore, pollen tube elongation was determined to be more sensitive to acid rain than pollen germination. The pH values below 3.1 resulted in complete destruction of pollen tubes. Pollen germination entirely stopped at around pH 3.0. Finally, it has been shown that the acid rain has a blocking effect on pollen germination and pollen tube elongation in apple. The conclusion is that not only pH value but also the quantity of acid rain is important factor in germination. The results were found statistically significant through the LSD test at levels of p < 0.05 and p < 0.01.

  2. Effect of cadmium on germination, coleoptile and root growth of barley seeds in the presence of gibberellic acid and kinetin.

    PubMed

    Munzuroglu, Omer; Zengin, Fikriye Kirbag

    2006-10-01

    Effect of cadmium on barley seeds treated with kinetin and gibberellic acid was investigated. As usual, cadmium has inhibited seed germination, and showed important inhibitory effects on roots and coleoptile growth after germination. In general, increase in cadmium concentration caused a greater inhibition of germination, root and coleoptile growth. The adverse effect of cadmium on root and coleoptile growth was more pronounced than that on germination. While testa was pierced by radicle (an indication of germination), no root or coleoptile development was observed above at concentration of 3-9.5 mM CdCl2xH2O. Low concentrations of cadmium have inhibited the root growth more than it did on coleoptile growth. Treatment of seeds with gibberellic acid and kinetin did not show any significant difference on the effect of cadmium in germination. However, inhibition of coleoptile elongation by cadmium has decreased a very much after kinetin application. The same result, although with lower rates when compared to kinetin, has been obtained for GA3 as well. In addition, the inhibitory effect of cadmium on root growth increased even more after kinetin application. The results have been found statistically significant through the least significant different (LSD) test at levels ofp < 0.05 and p < 0.01.

  3. Role of charred wood, heat-shock and light in germination of postfire phrygana species from the eastern Mediterranean Basin

    USGS Publications Warehouse

    Keeley, Jon E.; Babr-Keeley, Melanie

    1999-01-01

    Seeds of 22 species collected from recently burned phrygana were tested for their response to fire-type cues of charred wood and heat-shock. All Cistus species were stimulated by brief heat-shock, as shown in previous studies; however, none responded to charred wood. Only one of the 22 species was stimulated by charred wood, and only in dark-inhibited seeds, and this response did not occur in the light. The lack of charred-wood-induced germination is in contrast to the substantial proportion of species with this germination response reported for mediterranean-type vegetation in California, the Cape region of South Africa, and Western Australia. Phrygana has many species with heat-shock-stimulated germination, primarily in the Fabaceae and Cistaceae. This germination cue is widespread in these two families, thus, the presence of heat-shock-stimulated germination is a result of homologous, rather than covergent, adaptations in mediterranean-climate ecosystems. Germination response to light was not randomly distributed with respect to fire-type response. Heat-shock-stimulated species were almost uniformly light neutral, in contrast to more opportunistic colonizing species with non-refractory seeds, in which half of the species responded positively or negatively to light.

  4. Some effects of applied stress on early stages of cavitation damage. [test facilities for analyzing cavitation flow damage

    NASA Technical Reports Server (NTRS)

    Kemppainen, D. J.; Hammitt, F. G.

    1974-01-01

    The phenomenon of cavitation flow damage is discussed. The initial phases of damage and the effect of external stresses on the extent to which damage is incurred are analyzed. Three experimental facilities were used to procure the data required: (1) a water loop with venturi, (2) a mercury loop with venturi, and (3) a vibratory facility (stationary specimen, nonflow system). A description of each system is provided for the clarification of test conditions. Photographs of typical cavitation damage instances are included.

  5. Generation of recombinant rabies Virus CVS-11 expressing eGFP applied to the rapid virus neutralization test.

    PubMed

    Xue, Xianghong; Zheng, Xuexing; Liang, Hongru; Feng, Na; Zhao, Yongkun; Gao, Yuwei; Wang, Hualei; Yang, Songtao; Xia, Xianzhu

    2014-04-01

    The determination of levels of rabies virus-neutralizing antibody (VNA) provides the foundation for the quantitative evaluation of immunity effects. The traditional fluorescent antibody virus neutralization test (FAVN) using a challenge virus standard (CVS)-11 strain as a detection antigen and staining infected cells with a fluorescein isothiocyanate (FITC)-labeled monoclonal antibody, is expensive and high-quality reagents are often difficult to obtain in developing countries. Indeed, it is essential to establish a rapid, economical, and specific rabies virus neutralization test (VNT). Here, we describe a recombinant virus rCVS-11-eGFP strain that stably expresses enhanced green fluorescent protein (eGFP) based on a reverse genetic system of the CVS-11 strain. Compared to the rCVS-11 strain, the rCVS-11-eGFP strain showed a similar growth property with passaging stability in vitro and pathogenicity in vivo. The rCVS-11-eGFP strain was utilized as a detection antigen to determine the levels of rabies VNAs in 23 human and 29 canine sera; this technique was termed the FAVN-eGFP method. The good reproducibility of FAVN-eGFP was tested with partial serum samples. Neutralization titers obtained from FAVN and FAVN-eGFP were not significantly different. The FAVN-eGFP method allows rapid economical, specific, and high-throughput assessment for the titration of rabies VNAs.

  6. Experimental test program for evaluation of solid lubricant coating as applied to compliant foil gas bearings to 315 deg C

    NASA Technical Reports Server (NTRS)

    Wagner, R. C.

    1985-01-01

    An experimental apparatus and test procedure was developed to compare the performance of two solid lubricant coatings for air lubricated compliant foil gas bearings in the temperature range of 25 to 315 C. Polyimide bonded additive (SBGC) were tested extensively for durability and frictional characteristics. A partial arc bearing constructed of Inconel X-750 was coated on the bore with one of these coatings. The foil was subjected to repeated start/stop cycles. Performance comparisons reveal that although both coatings survive thousands of start/stop cycles, only the PBGF coated bearing achieves the specified 9000 start/stops. There is enough wear on the SBGC coated bearing to warrant termination of the test prior to 9000 start/stop cycles due to coating failure. The frictional characteristics of the PBGF are better at the elevated temperatures than at lower temperatures; a marked increase in sliding friction occurs as the temperature decreases. The SBGC maintains relatively constant frictional characteristics independent of operating temperature.

  7. Mass Spectrometry Applied to Bottom-Up Proteomics: Entering the High-Throughput Era for Hypothesis Testing

    NASA Astrophysics Data System (ADS)

    Gillet, Ludovic C.; Leitner, Alexander; Aebersold, Ruedi

    2016-06-01

    Proteins constitute a key class of molecular components that perform essential biochemical reactions in living cells. Whether the aim is to extensively characterize a given protein or to perform high-throughput qualitative and quantitative analysis of the proteome content of a sample, liquid chromatography coupled to tandem mass spectrometry has become the technology of choice. In this review, we summarize the current state of mass spectrometry applied to bottom-up proteomics, the approach that focuses on analyzing peptides obtained from proteolytic digestion of proteins. With the recent advances in instrumentation and methodology, we show that the field is moving away from providing qualitative identification of long lists of proteins to delivering highly consistent and accurate quantification values for large numbers of proteins across large numbers of samples. We believe that this shift will have a profound impact for the field of proteomics and life science research in general.

  8. An overview of tests for animal tissues in feeds applied in response to public health concerns regarding bovine spongiform encephalopathy.

    PubMed

    Gizzi, G; van Raamsdonk, L W D; Baeten, V; Murray, I; Berben, G; Brambilla, G; von Holst, C

    2003-04-01

    Enforcing the ban on meat-and-bone meal in feed for farmed animals, and especially ruminants, is considered an important measure to prevent the spread of bovine spongiform encephalopathy. The authors describe current analytical methods for the detection and identification of animal tissues in feed. In addition, recently approved requirements, such as the ban of intra-species recycling (practice of feeding an animal species with proteins derived from the bodies, or parts of bodies, of the same species) are described. In principle, four different approaches are currently applied, i.e. microscopic analysis, polymerase chain reaction, immunoassay analysis and near infrared spectroscopy or microscopy. The principal performance characteristics of these methods are presented and compared, and their specific advantages and disadvantages described. Special emphasis is also placed on the impact of rendering conditions, particularly high temperatures and on the use of molecular biology techniques.

  9. Suppression of Pythium spp. by Trichoderma spp. during germination of tomato seeds in soilless growing media.

    PubMed

    Aerts, R; De Schutter, B; Rombouts, L

    2002-01-01

    In the Flemish horticulture Pythium spp. is an important pathogen of tomato plants (Lycopersicon esculenthum) in soilless growing media. Therefore some experiments were conducted to evaluate the possibility of decreasing the damage caused by Pythium spp. by Trichoderma spp. In a tray with several growing media, a suspension of Trichoderma conidia (10(6)/ml growing medium) was applied two weeks before sowing. On some objects, a compost extract (Biostimulus) was added. The growing media used in the experiment were rockwool, recycled rockwool and recycled coconut fibre. After sowing, the trays were covered with perlite. Three isolates of Trichoderma spp.: T. asperellum (Biofungus), T. harzianum (Tri 003) and Trichoderma sp. (KHK) and two isolates of Pythium spp.: P. ultimum (MUCL) en P. aphanidermatum (HRI, UK) were used. Propamocarb was used as a chemical standard. The use of coconut fibre growing medium resulted in a higher percentage (36%) of germination than the rockwool media when only Pythium spp. was used. The presence of the spontaneous developing microflora in the coconut fibre medium gave probably also a suppression of Pythium spp. For that reason the results of the suppression by Trichoderma spp. are not easy to explain and very variable on the different objects. Pythium ultimum was more suppressed than P. aphanidermatum on all the growing media and the application of all the Trichoderma isolates increased the germination percentage of tomato seeds. T. asperellum (Biofungus) gave on rockwool also a good result for the suppression of P. aphanidermatum (increasing of germination with 48%). This effect was comparable with the propamocarb treatment (48%). T. harzianum (Tri 003) gave a small suppression (22%) and Trichoderma sp. (KHK) gave almost no suppression of P. aphanidermatum (7%). When less Trichoderma conidia were applied the germination percentage decreased. The adding of a compost extract (Biostimulus) had no influence on the results. This experiment

  10. Applying Principles of Universal Design to Test Delivery: The Effect of Computer-Based Read-Aloud on Test Performance of High School Students with Learning Disabilities

    ERIC Educational Resources Information Center

    Dolan, Robert P.; Hall, Tracey E.; Banerjee, Manju; Chun, Euljung; Strangman, Nicole

    2005-01-01

    Standards-based reform efforts are highly dependent on accurate assessment of all students, including those with disabilities. The accuracy of current large-scale assessments is undermined by construct-irrelevant factors including access barriers, a particular problem for students with disabilities. Testing accommodations such as the read-aloud…

  11. Germination of vegetable seeds exposed to very high pressure

    NASA Astrophysics Data System (ADS)

    Mori, Y.; Yokota, S.; Ono, F.

    2012-07-01

    Effects of high hydrostatic pressure were investigated on vegetable seeds in the GPa range to examine the potentialities of breed improvement by high-pressure processing. Specimens of several seeds of broccoli (Brassica oleracea var. italica), Turnip leaf (Brassica rapa var. perviridis) and Potherb Mustard (Brassica rapa var. nipposinica) were put in a teflon capsule with liquid high pressure medium, fluorinate, and inserted into a pyrophillite cube. By using a cubic anvil press a hydrostatic pressure of 5.5 GP a was applied to these seeds for 15 minutes. After being brought back to ambient pressure, they were seeded on humid soil in a plant pot. Many of these vegetable seeds began to germinate within 6 days after seeded.

  12. Effects of Three Fire-Suppressant Foams on the Germination and Physiological Responses of Plants

    NASA Astrophysics Data System (ADS)

    Song, Uhram; Mun, Saeromi; Waldman, Bruce; Lee, Eun Ju

    2014-10-01

    Suppressant foams used to fight forest fires may leave residual effects on surviving biota that managers need to consider prior to using them. We examined how three fire-suppressant foams (FSFs) (Forexpan S, Phos-Chek-WD881, and Silv-ex) affected seed germination and physiological responses of three plant species. Exposure to FSFs, whether in diluted concentrations or those typical in the field, reduced final germination percentages of seeds grown in petri dishes and within growth chambers. However, the FSFs did not cause total germination failure in any treatment. Inhibition of germination increased with longer exposure times, but only to diluted FSF solutions. Unlike in the laboratory experiments, none of the three FSFs affected seedling emergence when tested in field conditions. Further, we found no evidence of long-term phytotoxic effects on antioxidant enzyme activity nor chlorophyll content of the plant saplings. Therefore, although the three FSFs showed evidence of phytotoxicity to plants in laboratory tests, their actual impact on terrestrial ecosystems may be minimal. We suggest that the benefits of using these FSFs to protect plants in threatened forest ecosystems outweigh their minor risks.

  13. Oxidative signaling in seed germination and dormancy

    PubMed Central

    El-Maarouf-Bouteau, Hayat

    2008-01-01

    Reactive Oxygen Species (ROS) play a key role in various events of seed life. In orthodox seeds, ROS are produced from embryogenesis to germination, i.e., in metabolically active cells, but also in quiescent dry tissues during after ripening and storage, owing various mechanisms depending on the seed moisture content. Although ROS have been up to now widely considered as detrimental to seeds, recent advances in plant physiology signaling pathways has lead to reconsider their role. ROS accumulation can therefore be also beneficial for seed germination and seedling growth by regulating cellular growth, ensuring a protection against pathogens or controlling the cell redox status. ROS probably also act as a positive signal in seed dormancy release. They interact with abscisic acid and gibberellins transduction pathway and are likely to control numerous transcription factors and properties of specific protein through their carbonylation. PMID:19513212

  14. Microbe-Mediated Germination of Ascospores of Monosporascus cannonballus.

    PubMed

    Stanghellini, M E; Kim, D H; Waugh, M

    2000-03-01

    ABSTRACT Ascospores of Monosporascus cannonballus germinated readily in the rhizosphere of cantaloupe plants growing in field soil. However, little or no germination occurred in the rhizosphere of melon plants growing in field soil that was autoclaved prior to infestation with ascospores. The latter data suggested that root exudates alone do not stimulate ascospore germination and that the soil microflora may be involved in the induction of ascospore germination. Amending field soil with streptomycin (which inhibits gram-negative microorganisms) did not suppress ascospore germination in the rhizosphere of cantaloupe plants. However, amending the soil with penicillin (which inhibits gram-positive microorganisms) did suppress ascospore germination. Pentachloronitrobenzene (PCNB), which inhibits the gram-positive actinomycetes but does not inhibit gram-positive or gram-negative bacteria, also suppressed ascospore germination. These results suggest that actinomycetes, either directly or indirectly, are involved in the induction of ascospore germination in field soil in the presence of exudates from cantaloupe roots. Optimum germination occurred at temperatures ranging from 25 to 35 degrees C, and data indicate that a high percentage (>/=72%) of the ascospore population within 500 mum of a root are capable of germination and subsequent penetration of cantaloupe roots. PMID:18944615

  15. Response of Bacillus Spores to Combinations of Germinative Compounds

    PubMed Central

    Foerster, Harold F.; Foster, J. W.

    1966-01-01

    Foerster, Harold F. (University of Texas, Austin), and J. W. Foster. Response of Bacillus spores to combinations of germinative compounds. J. Bacteriol. 91:1168–1177. 1966.—Spores of 21 strains of Bacillus megaterium and 25 other strains representing 13 species of Bacillus were produced under standardized conditions. The germination of a washed spore suspension of each strain was measured as a response to various combinations of 30 different germinative compounds. The strains were first typed with respect to their response to “primary” germination compounds, i.e., glucose, l-alanine, inosine, and l-alanine-inosine mixture, and also Na+ and K+. The second stage was the determination of the response to various organic and inorganic anions and cations, each strain being supplied with the “primary” compounds best for it. Marked differences in germination patterns were observed among species and strains of the same species. No relation to established taxonomic lines was evident. A nonspecific requirement for ions was found for all strains, but not all ions were effective. A striking degree of interchangeability of germinative chemicals was found. “Fractional germination” was very common. A mixture of l-alanine and inosine and various ions was the best germinative solution for most strains. Some anomalous germination patterns were encountered. Those studied included a strain whose cells lysed spontaneously upon germination and other strains for which l-leucine had striking germinative powers. PMID:4956331

  16. Elucidating the germination transcriptional program using small molecules.

    PubMed

    Bassel, George W; Fung, Pauline; Chow, Tsz-fung Freeman; Foong, Justin A; Provart, Nicholas J; Cutler, Sean R

    2008-05-01

    The transition from seed to seedling is mediated by germination, a complex process that starts with imbibition and completes with radicle emergence. To gain insight into the transcriptional program mediating germination, previous studies have compared the transcript profiles of dry, dormant, and germinating after-ripened Arabidopsis (Arabidopsis thaliana) seeds. While informative, these approaches did not distinguish the transcriptional responses due to imbibition, shifts in metabolism, or breaking of dormancy from those triggered by the initiation of germination. In this study, three mechanistically distinct small molecules that inhibit Arabidopsis seed germination (methotrexate, 2, 4-dinitrophenol, and cycloheximide) were identified using a small-molecule screen and used to probe the germination transcriptome. Germination-responsive transcripts were defined as those with significantly altered transcript abundance across all inhibitory treatments with respect to control germinating seeds, using data from ATH1 microarrays. This analysis identified numerous germination regulators as germination responsive, including the DELLA proteins GAI, RGA, and RGL3, the abscisic acid-insensitive proteins ABI4, ABI5, ABI8, and FRY1, and the gibberellin receptor GID1A. To help visualize these and other publicly available seed microarray data, we designed a seed mRNA expression browser using the electronic Fluorescent Pictograph platform. An overall decrease in gene expression and a 5-fold greater number of transcripts identified as statistically down-regulated in drug-inhibited seeds point to a role for mRNA degradation or turnover during seed germination. The genes identified in our study as responsive to germination define potential uncharacterized regulators of this process and provide a refined transcriptional signature for germinating Arabidopsis seeds.

  17. Germination and seedling vigor in Beta vulgaris

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One former commercial variety, EL-A012206 (ACH185), and the pollen parent for the commercial variety USH20, EL-A015030 (SP7622) were germinated in H2O and 0.3% H2O2. Samples were collected at 0, 3, 6, 12, 18 and 24 hours of treatment for both varieties. RNA was extracted from the tissue and RT-PCR w...

  18. Effects of pre-treatments and temperature on seed viability and germination of Juniperus macrocarpa Sm.

    PubMed

    Pinna, Maria Silvia; Mattana, Efisio; Cañadas, Eva Maria; Bacchetta, Gianluigi

    2014-05-01

    The effects of collecting season, collection site, laboratory pre-treatments and temperatures on seed viability and germination of Juniperus macrocarpa were investigated. Ripe cones were collected in four Sardinian dune systems, in two seasons, from plant and soil. Warm (W) and cold (C) stratifications, two combinations of them (W+C, C+W), and no pre-treatment (0) were applied. Seeds were incubated in a range of constant (10-25°C) and an alternating (25/10°C) temperature regime. Seed viability was low (ca. 40%) and varied significantly according to the collecting season. Seed germination was also low (ca. 10%), the 0 and W were the most effective pre-treatments on stimulating germination. The best germination temperature, without any pre-treatment, was 15°C (ca. 20%). J. macrocarpa seeds are dormant and the achieved results suggested that the presence of secondary dormancy is induced by cold stratification. Spring appeared to be the best season for seed collecting, whereas autumn was the best for sowing. These results give new findings for restoration activities on this species.

  19. In situ investigation of Geobacillus stearothermophilus spore germination and inactivation mechanisms under moderate high pressure.

    PubMed

    Georget, Erika; Kapoor, Shobhna; Winter, Roland; Reineke, Kai; Song, Youye; Callanan, Michael; Ananta, Edwin; Heinz, Volker; Mathys, Alexander

    2014-08-01

    Bacterial spores are a major concern for food safety due to their high resistance to conventional preservation hurdles. Innovative hurdles can trigger bacterial spore germination or inactivate them. In this work, Geobacillus stearothermophilus spore high pressure (HP) germination and inactivation mechanisms were investigated by in situ infrared spectroscopy (FT-IR) and fluorometry. G. stearothermophilus spores' inner membrane (IM) was stained with Laurdan fluorescent dye. Time-dependent FT-IR and fluorescence spectra were recorded in situ under pressure at different temperatures. The Laurdan spectrum is affected by the lipid packing and level of hydration, and provided information on the IM state through the Laurdan generalized polarization. Changes in the -CH2 and -CH3 asymmetric stretching bands, characteristic of lipids, and in the amide I' band region, characteristic of proteins' secondary structure elements, enabled evaluation of the impact of HP on endospores lipid and protein structures. These studies were complemented by ex situ analyses (plate counts and microscopy). The methods applied showed high potential to identify germination mechanisms, particularly associated to the IM. Germination up to 3 log10 was achieved at 200 MPa and 55 °C. A molecular-level understanding of these mechanisms is important for the development and validation of multi-hurdle approaches to achieve commercial sterility.

  20. Seed Germination in Chenopodium album L: Relationships between Nitrate and the Effects of Plant Hormones.

    PubMed

    Saini, H S; Bassi, P K; Spencer, M S

    1985-04-01

    Effects of ethylene, gibberellins, and kinetin on the germination of two lots of Chenopodium album L. seeds, collected from the field in 1982 and 1983, were studied in relation to the availability of nitrate. The experiments were conducted in darkness and at temperatures ranging from 12 to 32 degrees C. Ethylene induced over 75% germination in the 1983 seed but had little effect on the 1982 seed. Nitrate was only slightly promotive in either of the two seed lots. A combination of ethylene and nitrate, however, acted synergistically on 1982 seed, resulting in as much germination as that induced in 1983 seed by ethylene alone. In 1983 seed, a combination of ethylene and nitrate was only marginally more effective than ethylene. A similar relationship was observed in the effects of gibberellic acid(4+7) (GA(4+7)) and nitrate on seeds from the two lots. The 1982 seed, which responded synergistically to combinations of nitrate with ethylene or GA(4+7) was found to contain an extremely low endogenous level of nitrate as compared to 1983 seed. Thus, high levels of either endogenous or applied nitrate appeared to enhance the germination response to ethylene or GA(4+7).Kinetin had no effect on 1982 seed and only a small promotive effect on 1983 seed. There was no synergism between kinetin and nitrate in either of the seed lots.

  1. In situ investigation of Geobacillus stearothermophilus spore germination and inactivation mechanisms under moderate high pressure.

    PubMed

    Georget, Erika; Kapoor, Shobhna; Winter, Roland; Reineke, Kai; Song, Youye; Callanan, Michael; Ananta, Edwin; Heinz, Volker; Mathys, Alexander

    2014-08-01

    Bacterial spores are a major concern for food safety due to their high resistance to conventional preservation hurdles. Innovative hurdles can trigger bacterial spore germination or inactivate them. In this work, Geobacillus stearothermophilus spore high pressure (HP) germination and inactivation mechanisms were investigated by in situ infrared spectroscopy (FT-IR) and fluorometry. G. stearothermophilus spores' inner membrane (IM) was stained with Laurdan fluorescent dye. Time-dependent FT-IR and fluorescence spectra were recorded in situ under pressure at different temperatures. The Laurdan spectrum is affected by the lipid packing and level of hydration, and provided information on the IM state through the Laurdan generalized polarization. Changes in the -CH2 and -CH3 asymmetric stretching bands, characteristic of lipids, and in the amide I' band region, characteristic of proteins' secondary structure elements, enabled evaluation of the impact of HP on endospores lipid and protein structures. These studies were complemented by ex situ analyses (plate counts and microscopy). The methods applied showed high potential to identify germination mechanisms, particularly associated to the IM. Germination up to 3 log10 was achieved at 200 MPa and 55 °C. A molecular-level understanding of these mechanisms is important for the development and validation of multi-hurdle approaches to achieve commercial sterility. PMID:24750808

  2. Applying Disruptive Preference Test Protocols to Increase the Number of "No Preference" Responses in the Placebo Pair, Using Chinese Consumers.

    PubMed

    Xia, Yixun; Zhong, Fang; O'Mahony, Michael

    2016-09-01

    One form of paired preference test protocol requires consumers to assess 2 pairs of products. One is the target pair under consideration, while the other is a putatively identical pair named the "placebo pair" which is also presented as a control. Counterintuitively, the majority of consumers report preferences when presented with the placebo pair. Their response frequencies are hypothesized to be those of consumers having "no preference" and are compared with the response frequencies elicited by a target pair, to determine whether the target pair elicits significant preferences. The primary goal of this paper was to study the robustness of 2 new so called disruptive protocols that reduced the proportion of consumers, who reported preferences when assessing a putatively identical pair of products. For this task, the tests were performed in a different language, in a different country, using different products from before. The results showed that the proportion of consumers reporting preferences for the placebo pair was reduced, confirming earlier work. Also, comparison of d' values showed a lack of significant overall differences between the placebo and target pairs, while chi-squared analyses indicated significant differences in the response frequencies. This indicated that the sample was segmented into 2 balanced groups with opposing preferences.

  3. Applying Disruptive Preference Test Protocols to Increase the Number of "No Preference" Responses in the Placebo Pair, Using Chinese Consumers.

    PubMed

    Xia, Yixun; Zhong, Fang; O'Mahony, Michael

    2016-09-01

    One form of paired preference test protocol requires consumers to assess 2 pairs of products. One is the target pair under consideration, while the other is a putatively identical pair named the "placebo pair" which is also presented as a control. Counterintuitively, the majority of consumers report preferences when presented with the placebo pair. Their response frequencies are hypothesized to be those of consumers having "no preference" and are compared with the response frequencies elicited by a target pair, to determine whether the target pair elicits significant preferences. The primary goal of this paper was to study the robustness of 2 new so called disruptive protocols that reduced the proportion of consumers, who reported preferences when assessing a putatively identical pair of products. For this task, the tests were performed in a different language, in a different country, using different products from before. The results showed that the proportion of consumers reporting preferences for the placebo pair was reduced, confirming earlier work. Also, comparison of d' values showed a lack of significant overall differences between the placebo and target pairs, while chi-squared analyses indicated significant differences in the response frequencies. This indicated that the sample was segmented into 2 balanced groups with opposing preferences. PMID:27526947

  4. Brassinosteroids promote Arabidopsis pollen germination and growth.

    PubMed

    Vogler, Frank; Schmalzl, Christina; Englhart, Maria; Bircheneder, Martin; Sprunck, Stefanie

    2014-09-01

    Pollen tubes are among the fastest tip-growing plant cells and represent an excellent experimental system for studying the dynamics and spatiotemporal control of polarized cell growth. However, investigating pollen tube tip growth in the model plant Arabidopsis remains difficult because in vitro pollen germination and pollen tube growth rates are highly variable and largely different from those observed in pistils, most likely due to growth-promoting properties of the female reproductive tract. We found that in vitro grown Arabidopsis pollen respond to brassinosteroid (BR) in a dose-dependent manner. Pollen germination and pollen tube growth increased nine- and fivefold, respectively, when media were supplemented with 10 µM epibrassinolide (epiBL), resulting in growth kinetics more similar to growth in vivo. Expression analyses show that the promoter of one of the key enzymes in BR biosynthesis, CYP90A1/CPD, is highly active in the cells of the reproductive tract that form the pathway for pollen tubes from the stigma to the ovules. Pollen tubes grew significantly shorter through the reproductive tract of a cyp90a1 mutant compared to the wild type, or to a BR perception mutant. Our results show that epiBL promotes pollen germination and tube growth in vitro and suggest that the cells of the reproductive tract provide BR compounds to stimulate pollen tube growth.

  5. Direct simulation of heterogeneous diffusion and inversion procedure applied to an out-diffusion experiment. Test case of Palmottu granite.

    PubMed

    Sardini, P; Robinet, J C; Siitari-Kauppi, M; Delay, F; Hellmuth, K H

    2007-08-15

    An out-diffusion laboratory experiment using a non-reactive tracer was fitted using the Time Domain Diffusion (TDD) method. This rapid particle tracking method allows simulation of the heterogeneous diffusion based on pore-scale images and local values of diffusivities. The superimposed porosity and mineral 2D maps act as computation grids to condition diffusion pathways. We focused on a Palmottu granite sample, in which the connected pore space has a composite microstructure with cracks linking microporous minerals and is above the percolation threshold. Three main results were achieved: (i) When compared to the fitting obtained with one coefficient (best mean square residual R = 1.6 x 10(-2)), diffusion is shown to be suitably characterised with two coefficients related to cracks and microporous minerals (best R = 6.5 x 10(-4)), (ii) rather than imposing a local apparent diffusion coefficient D(a) independent of the local porosity Phi, a best fit is obtained by applying Archie's relationship D(a) = D(0) x G with G = Phi(m) to each pixel of the calculation grids (G is the geometry factor, D(0) is the diffusion coefficient in free fluid, and m is Archie's exponent), and (iii) the order of magnitude of the fitted diffusion coefficient or Archie's exponents (m=0 for microcracks and m=1.82 for microporous minerals) is physically realistic.

  6. Applying the Triangle Taste Test to Assess Differences between Low Sodium Salts and Common Salt: Evidence from Peru

    PubMed Central

    Saavedra-Garcia, Lorena; Bernabe-Ortiz, Antonio; Gilman, Robert H.; Diez-Canseco, Francisco; Cárdenas, María Kathia; Sacksteder, Katherine A.; Miranda, J. Jaime

    2015-01-01

    Background In resourced-constrained settings, daily cooking practices are still the norm. Replacing sodium in regular salt to produce potassium-enriched salts are potential alternative routes to reduce sodium intake, paired with the benefit associated with potassium intake. This change would likely have effects on palatability and taste of prepared foods, yet a threshold to discriminate sensorial changes can be determined. The main goal of this study was to assess if the use of potassium-enriched salt substitutes lead to perceived differences in taste utilizing a sensory discrimination test. Methods and Results A triangle taste test was conducted and participants were offered samples of cooked rice prepared with different salts. The only ingredient that differed in the preparation was the salt used: 100%NaCl (regular salt) and salts where sodium was replaced by 50%, 33% or 25% KCl (potassium-enriched salt). Comparisons were carried out according to the minimum number of correct judgments. A total of 156 subjects, 49% males, mean age 41.0 years (SD±15.5) years, participated in the study. Samples using 25% potassium-enrichment were indistinguishable in terms of taste from regular salt, whereas samples with 33% and 50% potassium-enrichment were distinguishable. Results were consistent when stratified by sex and age. Less than 10% of participants attributed the differences to bitterness or metallic flavor. Conclusions The 25% potassium-enriched salt is indistinguishable from regular salt. These findings suggest a potential to achieve sodium intake reduction strategies in cooking practices by substituting regular salt with potassium-enriched salt without affecting palatability. PMID:26225848

  7. Plant Viability as a Function of Temperature Stress (The Richards Function Applied to Data from Freezing Tests of Growing Shoots).

    PubMed Central

    Von Fircks, H. A.; Verwijst, T.

    1993-01-01

    Frost resistance of growing Salix viminalis L. shoots was determined by rating mortality percentage under two commonly used freezing conditions: a condition in which plants were encased in crushed ice and another in which plants were moistened with tap water prior to freezing. The mortality-temperature data were fitted with a logistic function (having a fixed inflection point halfway between the asymptotes) and with a Richards function, which is a double asymptotic sigmoid function with a variable inflection point. Different frost resistance curves were obtained, depending on the freezing conditions used. However, conditions were inadequate for efficient ice nucleation under either condition. This implies that the applied freezing conditions are not suitable when the purpose is to induce and duplicate early ice crystal formation conditions. The Richards derivatives were negatively skewed in the one case and positively skewed in the other case, giving inflection points, as a function of the upper asymptote, situated at 0.37 when shoots were frosted in the presence of ice and at 0.81 when shoots were frozen in the presence of added moisture. These values differed significantly from 0.50, through which the logistic function would have forced the curves. Because of the significant asymmetry in these frost-resistance curves, the Richards function led to a more accurate reflection of the temperature-mortality course of growing Salix stems than the logistic function. The Richards function possesses the flexibility needed to describe plant injury response in terms of physical and plant physiological mechanisms. Therefore, the Richards function is recommended rather than the logistic function for the assessment of frost resistance. PMID:12231919

  8. Applying a gender lens on human papillomavirus infection: cervical cancer screening, HPV DNA testing, and HPV vaccination

    PubMed Central

    2013-01-01

    Background Our aim is to provide a state-of-the-art overview of knowledge on sex (biological) and gender (sociocultural) aspects of Human papillomavirus (HPV) and cervical cancer for educational purposes. Considerable disparities exist in cervical cancer incidences between different subgroups of women. We provide an outline on the crucial issues and debates based on the recent literature published in leading gender medicine journals. Intersectionality was applied in order to help categorise the knowledge. Methods Key terms (HPV, cervical cancer) were screened in Gender Medicine, Journal of Women’s Health and Women & Health from January 2005-June 2012. Additional searches were conducted for topics insufficiently mentioned, such as HPV vaccination of boys. In total, 71 publications were included (56 original papers, four reviews, six reports, three commentaries, one editorial and one policy statement). Results Research reveals complexity in the way various subgroups of women adhere to cervical screening. Less educated women, older women, uninsured women, homeless women, migrant women facing language barriers, women who have sex with women and obese women participate in Pap smears less frequently. A series of barriers can act to impede decisions to vaccinate against HPV. Conclusions Both male and female controlled preventive methods and treatment measures should be developed in order to tackle HPV infection and different strategies are needed for different subgroups. A substantial discussion and research on alternative methods of prevention was and is lacking. In future research, sex and gender aspects of HPV-related diseases of boys and men as well as subgroup differences in HPV risk need to be addressed. PMID:23394214

  9. Delta distributary dynamics in the Skagit River Delta (Washington, USA): Extending, testing, and applying avulsion theory in a tidal system

    NASA Astrophysics Data System (ADS)

    Hood, W. Gregory

    2010-11-01

    Analysis of historical aerial photos shows that Skagit Delta (Washington, USA) distributary dynamics are consistent with the Slingerland and Smith model of avulsion dynamics where the ratio of the water surface slopes of the two branches of a bifurcation predicts avulsion stability. This model was extended to predict distributary inlet (upstream) width and bankfull cross-sectional area. The water surface gradient ratio for a bifurcation pair predicted distributary width well; the lowest R2 was 0.61 for the 1937 data points, but R2 ranged from 0.83 to 0.90 for other year-specific regression lines. Gradient ratios were not constant over the historical record; from 1937 to 1972 the mainstem river channel lengthened by 1250 m in the course of marsh progradation, while distributary lengthening was comparatively negligible. Consequently, the gradient advantage of the distributaries increased and their channels widened. After the mainstem river terminus stabilized from 1972 to the present, the distributaries continued to lengthen with marsh progradation, so that distributary gradient advantage steadily declined and the distributaries narrowed. While distributary cross sections were not available for the historical period, they were surveyed in 2007 near the distributary inlets. Gradient ratio was more closely related to distributary inlet bankfull cross-sectional area ( R2 = 0.95) than to minimum distributary width for any photo year examined. Applying this form of analysis to Skagit Delta distributaries that have been dammed in the course of agricultural development suggests that their restoration to stabilize eroding marshes at their outlets and recover salmon migration pathways would be feasible without significant risk of full river avulsion.

  10. Plant Viability as a Function of Temperature Stress (The Richards Function Applied to Data from Freezing Tests of Growing Shoots).

    PubMed

    Von Fircks, H. A.; Verwijst, T.

    1993-09-01

    Frost resistance of growing Salix viminalis L. shoots was determined by rating mortality percentage under two commonly used freezing conditions: a condition in which plants were encased in crushed ice and another in which plants were moistened with tap water prior to freezing. The mortality-temperature data were fitted with a logistic function (having a fixed inflection point halfway between the asymptotes) and with a Richards function, which is a double asymptotic sigmoid function with a variable inflection point. Different frost resistance curves were obtained, depending on the freezing conditions used. However, conditions were inadequate for efficient ice nucleation under either condition. This implies that the applied freezing conditions are not suitable when the purpose is to induce and duplicate early ice crystal formation conditions. The Richards derivatives were negatively skewed in the one case and positively skewed in the other case, giving inflection points, as a function of the upper asymptote, situated at 0.37 when shoots were frosted in the presence of ice and at 0.81 when shoots were frozen in the presence of added moisture. These values differed significantly from 0.50, through which the logistic function would have forced the curves. Because of the significant asymmetry in these frost-resistance curves, the Richards function led to a more accurate reflection of the temperature-mortality course of growing Salix stems than the logistic function. The Richards function possesses the flexibility needed to describe plant injury response in terms of physical and plant physiological mechanisms. Therefore, the Richards function is recommended rather than the logistic function for the assessment of frost resistance. PMID:12231919

  11. Up in smoke: I. Smoke-derived germination cues for postfire annual,Nicotiana attenuata torr. Ex. Watson.

    PubMed

    Baldwin, I T; Staszak-Kozinski, L; Davidson, R

    1994-09-01

    Some postfire annuals with dormant seeds use heat or chemical cues from charred wood to synchronize their germination with the postfire environment. We report that wood smoke and polar extracts of wood smoke, but not the ash of burned wood, contain potent cue(s) that stimulate germination in the postfire annual plant,Nicotiana attenuata. We examined the responses of seeds from six populations of plants from southwest Utah to extracts of smoke and found the proportion of viable seeds that germinated in the presence of smoke cues to vary between populations but to be consistent between generations. With the most dormant genotypes, we examine three mechanisms by which smoke-derived chemical cues may stimulate germination (chemical scarification of the seed coat and nutritive- and signal-mediated stimulation of germination) and report that the response is consistent with the signal-mediated mechanism. The germination cue(s) found in smoke are produced by the burning of hay, hardwood branches, leaves, and, to a lesser degree, cellulose. Moreover, the cues are found in the common food condiment, "liquid smoke," and we find no significant differences between brands. With a bioassay-driven fractionation of liquid smoke, we identified 71 compounds in active fractions by GC-MS and AA spectrometry. However, when these compounds were tested in pure form or in combinations that mimicked the composition of active fractions over a range of concentrations, they failed to stimulate germination to the same degree that smoke fractions did. Moreover, enzymatic oxidation of some of these compounds also failed to stimulate germination. In addition, we tested 43 additional compounds also reported from smoke, 85 compounds that were structurally similar to those reported from smoke and 34 compounds reported to influence germination in other species. Of the 233 compounds tested, 16 proved to inhibit germination at the concentrations tested, and none reproduced the activity of wood smoke. By

  12. Ecophysiology of seed germination of wild Dahlia coccinea (Asteraceae) in a spatially heterogeneous fire-prone habitat

    NASA Astrophysics Data System (ADS)

    Vivar-Evans, Susana; Barradas, Víctor L.; Sánchez-Coronado, María E.; Gamboa de Buen, Alicia; Orozco-Segovia, Alma

    2006-03-01

    Dahlia coccinea grows on fire-prone xerophilous shrubland, on a lava field located in Mexico City. Two kinds of experiments were performed to test the role of fire and environmental heterogeneity on germination. The first experiment tested the effect of environmental conditions (constant and alternating temperatures, cold stratification and light). The second one tested the effects of fire and high temperatures (dry and moist heat) on germination. Seeds of Dahlia were indifferent to light. The seeds showed physiological dormancy, which was lost by after-ripening or by gibberellins. During simulated fires, dry seeds tolerated high temperatures of short duration and also withstood prolonged exposure to 60 °C. Dry heat treatment reduced the mechanical restriction for embryo growth in dormant seeds. Ash and prolonged exposure to moist heat inhibited germination. Exogenous gibberellins reversed the deleterious effects of prolonged exposure to moist heat. The effect of cold stratification was related to the seeds' physiological stage and to light conditions; stratification in the dark reduced germination. Seeds of D. coccinea could tolerate, evade, or be slightly favored by the effects of low intensity fires occurring in their habitat. Seed responses to treatments suggest that the spatially heterogeneous lava field could provide a wide variety of micro-sites where physiological dormancy could be broken and during fires seeds could maintain their viability and subsequently germinate and/or develop a seed bank.

  13. Some physicochemical properties of flour from germinated sorghum grain.

    PubMed

    Elkhalifa, Abd Elmoneim O; Bernhardt, Rita

    2013-02-01

    A Sudanese sorghum cultivar (Fetarita) was germinated for 3 days. Stability and clarity of sorghum pastes, freeze-thaw stability, gel consistency, and swelling power were measured every 24 h. There is no substantial difference in stability and clarity between flour samples from germinated and ungerminated sorghum, but a different behavior was observed between samples stored at room temperature and at 4 °C. Cooked paste derived from germinated sorghum flour presented higher syneresis than that derived from ungerminated sorghum flour over the first three cycles but when the cycle number increased, both flours showed zero syneresis value. For the gel consistency the flours derived from germinated sorghum produced thinnest gels. The neutral and acid gel consistency increased when the germination time increased. Germination had not much effect on the swelling power of sorghum flour.

  14. Numbers of individual nutrient germinant receptors and other germination proteins in spores of Bacillus subtilis.

    PubMed

    Stewart, Kerry-Ann V; Setlow, Peter

    2013-08-01

    Germination of dormant Bacillus subtilis spores with specific nutrient germinants is dependent on a number of inner membrane (IM) proteins, including (i) the GerA, GerB, and GerK germinant receptors (GRs) that respond to nutrient germinants; (ii) the GerD protein, essential for optimal GR function; and (iii) SpoVA proteins, essential for the release of the spore-specific molecule dipicolinic acid (DPA) during spore germination. Levels of GR A and C subunit proteins, GerD, and SpoVAD in wild-type spores were determined by Western blot analysis of spore fractions or total disrupted spores by comparison with known amounts of purified proteins. Surprisingly, after disruption of decoated B. subtilis spores with lysozyme and fractionation, ∼90% of IM fatty acids and GR subunits remained with the spores' insoluble integument fraction, indicating that yields of purified IM are low. The total lysate from disrupted wild-type spores contained ∼2,500 total GRs/spore: GerAA and GerAC subunits each at ∼1,100 molecules/spore and GerBC and GerKA subunits each at ∼700 molecules/spore. Levels of the GerBA subunit determined previously were also predicted to be ∼700 molecules/spore. These results indicate that the A/C subunit stoichiometry in GRs is most likely 1:1, with GerA being the most abundant GR. GerD and SpoVAD levels were ∼3,500 and ∼6,500 molecules/spore, respectively. These values will be helpful in formulating mathematic models of spore germination kinetics as well as setting lower limits on the size of the GR-GerD complex in the spores' IM, termed the germinosome.

  15. Seed germination characteristics of Chrysothamnus nauseosus ssp. viridulus (Astereae, Asteraceae)

    SciTech Connect

    Khan, M.A.; Sankhla, N.; Weber, D.J.; McArthur, E.D.

    1987-04-30

    Rubber rabbitbrush (Chrysothamnus nauseosus (Pallas) Britt. ssp. viridulus) may prove to be a source of high-quality cis-isoprene rubber, but its establishment is limited by a lack of information on seed germination. Consequently, seeds were germinated at alternating temperatures (5-15, 5-25, 15-25, and 20-30 C) in light and dark as well as constant temperatures (15-40 C with 5-C increments) to determine temperature response. Seeds were also germinated in solutions of polyethylene glycol 6000, salinity regimes at all the above-mentioned temperatures to determine salinity and temperature interaction. The hormones GA/sub 3/ and kinetin were used to study their effect on overcoming salt- and temperature-induced germination inhibition. Seeds of C. nauseosus ssp. viridulus were very sensitive to low temperature. Best germination was achieved at 25 and 30 C, but these seeds also germinated at a higher temperature (35 C). The seeds of rabbit brush germinated at both constant and alternating temperatures. Light appears to play little or no role in controlling germination of the seeds of rubber rabbitbrush. However, seeds of rabbitbrush were sensitive to salinity, and seed germination was progressively inhibited by increase in salt concentration, although a few seeds still germinated at the highest saline level. Progressively higher concentrations of polyethylene glycol also progressively inhibited germination. Suppression of seed germination induced by high salt concentrations and high temperatures can be partially alleviated by the application of either GA/sub 3/ or kinetin. 34 references, 5 figures, 3 tables.

  16. Expression of genes related to tolerance to low temperature for maize seed germination.

    PubMed

    Silva-Neta, I C; Pinho, E V; Veiga, A D; Pìnho, R G; Guimarães, R M; Caixeta, F; Santos, H O; Marques, T L

    2015-01-01

    The aim of this study was to characterize maize lines tolerant to cold temperatures during the germination process. Seeds from lines with different levels of tolerance to low temperatures were used; 3 lines were classified as tolerant and 3 as susceptible to low germination temperatures. A field was set up to multiply seeds from selected lines. After the seeds were harvested and classified, we conducted physiological tests and analyzed fatty acid content of palmitic, stearic, oleic, linoleic, linolenic, and eicosenoic acids. In proteomic analysis, the expression of heat-resistant proteins, including catalase, peroxidase, esterase, superoxide dismutase, and α-amylase, were evaluated. Transcript analysis was used to measure the expression of the genes AOX1, AOX2, ZmMPK-17, and ZmAN-13. The material showing the highest susceptibility to low germination temperatures contained high saturated fatty acid content. Expression of α-amylase in seeds soaked for 72 h at a temperature of 10°C was lower than expression of α-amylase when soaked at 25°C for the same amount of time. We observed variation in the expression of heat-resistant proteins in seeds of the lines evaluated. The genes AOX and Zm-AN13 were promising for use in identifying maize materials that are tolerant to low germination temperatures.

  17. Effects of indole amides on lettuce and onion germination and growth.

    PubMed

    Borgati, Thiago F; Boaventura, Maria Amelia D

    2011-01-01

    Auxins, such as indole-3-acetic acid (IAA), are important in plant germination and growth, while physiological polyamines, such as putrescine, are involved in cell proliferation and differentiation, and their concentrations increase during germination. In this work, novel indole amides were synthesized in good yields by monoacylation of morpholine and unprotected symmetrical diamines with indole-3-carboxylic acid, a putative metabolite of IAA, possessing no auxin-like activity. These amides were tested for their effects on seed germination and growth of the radicles and shoots of Lactuca sativa (lettuce) and Allium cepa (onion) seedlings, at 100.0, 1.0, and 0.01 microM concentrations. Germination was generally stimulated, with the exception of amide 3, derived from morpholine, at 100 microM. On radicle and shoot growth, the effect of these compounds was predominantly inhibitory. Compound 3 was the best inhibitor of growth of lettuce and onion, at the highest concentration. Amides, such as propanil, among others, are described as having herbicidal activity.

  18. Expression of genes related to tolerance to low temperature for maize seed germination.

    PubMed

    Silva-Neta, I C; Pinho, E V; Veiga, A D; Pìnho, R G; Guimarães, R M; Caixeta, F; Santos, H O; Marques, T L

    2015-01-01

    The aim of this study was to characterize maize lines tolerant to cold temperatures during the germination process. Seeds from lines with different levels of tolerance to low temperatures were used; 3 lines were classified as tolerant and 3 as susceptible to low germination temperatures. A field was set up to multiply seeds from selected lines. After the seeds were harvested and classified, we conducted physiological tests and analyzed fatty acid content of palmitic, stearic, oleic, linoleic, linolenic, and eicosenoic acids. In proteomic analysis, the expression of heat-resistant proteins, including catalase, peroxidase, esterase, superoxide dismutase, and α-amylase, were evaluated. Transcript analysis was used to measure the expression of the genes AOX1, AOX2, ZmMPK-17, and ZmAN-13. The material showing the highest susceptibility to low germination temperatures contained high saturated fatty acid content. Expression of α-amylase in seeds soaked for 72 h at a temperature of 10°C was lower than expression of α-amylase when soaked at 25°C for the same amount of time. We observed variation in the expression of heat-resistant proteins in seeds of the lines evaluated. The genes AOX and Zm-AN13 were promising for use in identifying maize materials that are tolerant to low germination temperatures. PMID:25867416

  19. Development of a test system to apply virus-containing particles to filtering facepiece respirators for the evaluation of decontamination procedures.

    PubMed

    Fisher, Edward; Rengasamy, Samy; Viscusi, Dennis; Vo, Evanly; Shaffer, Ronald

    2009-03-01

    A chamber to apply aerosolized virus-containing particles to air-permeable substrates (coupons) was constructed and validated as part of a method to assess the virucidal efficacy of decontamination procedures for filtering facepiece respirators. Coliphage MS2 was used as a surrogate for pathogenic viruses for confirmation of the efficacy of the bioaerosol respirator test system. The distribution of virus applied onto and within the coupons was characterized, and the repeatability of applying a targeted virus load was examined. The average viable virus loaded onto 90 coupons over the course of 5 days was found to be 5.09 +/- 0.19 log(10) PFU/coupon (relative standard deviation, 4%). To determine the ability to differentiate the effectiveness of disinfecting procedures with different levels of performance, sodium hypochlorite and steam treatments were tested in experiments by varying the dose and time, respectively. The role of protective factors was assessed by aerosolizing the virus with various concentrations of the aerosol-generating medium. A sodium hypochlorite (bleach) concentration of 0.6% and steam treatments of 45 s and longer resulted in log reductions (>4 logs) which reached the detection limits for both levels of protective factors. Organic matter (ATCC medium 271) as a protective factor afforded some protection to the virus in the sodium hypochlorite experiments but was not a factor in the steam experiments. The evaluation of the bioaerosol respirator test system demonstrated a repeatable method for applying a targeted viral load onto respirator coupons and provided insight into the properties of aerosols that are of importance to the development of disinfection assays for air-permeable materials. PMID:19139225

  20. Development of a Test System To Apply Virus-Containing Particles to Filtering Facepiece Respirators for the Evaluation of Decontamination Procedures▿

    PubMed Central

    Fisher, Edward; Rengasamy, Samy; Viscusi, Dennis; Vo, Evanly; Shaffer, Ronald

    2009-01-01

    A chamber to apply aerosolized virus-containing particles to air-permeable substrates (coupons) was constructed and validated as part of a method to assess the virucidal efficacy of decontamination procedures for filtering facepiece respirators. Coliphage MS2 was used as a surrogate for pathogenic viruses for confirmation of the efficacy of the bioaerosol respirator test system. The distribution of virus applied onto and within the coupons was characterized, and the repeatability of applying a targeted virus load was examined. The average viable virus loaded onto 90 coupons over the course of 5 days was found to be 5.09 ± 0.19 log10 PFU/coupon (relative standard deviation, 4%). To determine the ability to differentiate the effectiveness of disinfecting procedures with different levels of performance, sodium hypochlorite and steam treatments were tested in experiments by varying the dose and time, respectively. The role of protective factors was assessed by aerosolizing the virus with various concentrations of the aerosol-generating medium. A sodium hypochlorite (bleach) concentration of 0.6% and steam treatments of 45 s and longer resulted in log reductions (>4 logs) which reached the detection limits for both levels of protective factors. Organic matter (ATCC medium 271) as a protective factor afforded some protection to the virus in the sodium hypochlorite experiments but was not a factor in the steam experiments. The evaluation of the bioaerosol respirator test system demonstrated a repeatable method for applying a targeted viral load onto respirator coupons and provided insight into the properties of aerosols that are of importance to the development of disinfection assays for air-permeable materials. PMID:19139225

  1. Effect of sonic stimulation on Bacillus endospore germination.

    PubMed

    Liu, Si Li; Wu, Wen Jie; Yung, Pun To

    2016-01-01

    This study investigates the effect of sonic stimulation on Bacillus endospore germination. Germinating endospores in a microtiter plate were exposed to audible sound wave generated by an array of piezoelectric transducers. In situ germination kinetics was measured by terbium-dipicolinate fluorescence assay, optical density measurement and phase contrast microscopy. Fluorescence results revealed that sonic stimulation (5 kHz at 90 dB) promoted the germination speed by 43.7% ± 11.3% and final germination level by 61.7% ± 11.9% of Bacillus atrophaeus. This acoustic energy absorbed by endospores is postulated to change membrane permeability and increase enzyme activities; thereby, expediting the germination process. This also raises the likelihood of dormant endospores undergoing germination because of a rapid release of unidentified chemical mediators for quorum sensing. On the other hand, acoustic effect was not observed in B. subtilis endospores. This may be attributed to the different spore aspect ratio, 1.43 ± 0.05 for B. atrophaeus and 2.02 ± 0.08 for B. subtilis, which results in a difference in specific absorption rates towards audible sound waves. Our results demonstrate the modulation of endospore germination by an external field to shed light on germination mechanism and cell-wave interaction. PMID:26607285

  2. Evolution of 'smoke' induced seed germination in pyroendemic plants

    USGS Publications Warehouse

    Keeley, J. E.; Pausas, J.G.

    2016-01-01

    Pyroendemics are plants in which seedling germination and successful seedling recruitment are restricted to immediate postfire environments. In many fire-prone ecosystems species cue their germination to immediate postfire conditions. Here we address how species have evolved one very specific mechanism, which is using the signal of combustion products from biomass. This is often termed ‘smoke’ stimulated germination although it was first discovered in studies of charred wood effects on germination of species strictly tied to postfire conditions (pyroendemics). Smoke stimulated germination has been reported from a huge diversity of plant species. The fact that the organic compound karrikin (a product of the degradation of cellulose) is a powerful germination cue in many species has led to the assumption that this compound is the only chemical responsible for smoke-stimulated germination. Here we show that smoke-stimulated germination is a complex trait with different compounds involved. We propose that convergent evolution is a more parsimonious model for smoke stimulated germination, suggesting that this trait evolved multiple times in response to a variety of organic and inorganic chemical triggers in smoke. The convergent model is congruent with the evolution of many other fire-related traits.

  3. An analysis of B cell selection mechanisms in germinal centers.

    PubMed

    Meyer-Hermann, Michael E; Maini, Philip K; Iber, Dagmar

    2006-09-01

    Affinity maturation of antibodies during immune responses is achieved by multiple rounds of somatic hypermutation and subsequent preferential selection of those B cells that express B cell receptors with improved binding characteristics for the antigen. The mechanism underlying B cell selection has not yet been defined. By employing an agent-based model, we show that for physiologically reasonable parameter values affinity maturation can be driven by competition for neither binding sites nor antigen--even in the presence of competing secreted antibodies. Within the tested mechanisms, only clonal competition for T cell help or a refractory time for the interaction of centrocytes with follicular dendritic cells is found to enable affinity maturation while generating the experimentally observed germinal centre characteristics and tolerating large variations in the initial antigen density. PMID:16707510

  4. Seed germination ecology of Echinochloa glabrescens and its implication for management in rice (Oryza sativa L.).

    PubMed

    Opeña, Jhoana L; Chauhan, Bhagirath S; Baltazar, Aurora M

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE) and Los Baños (IR)] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88%) from light stimulation than did the IR population (34%). The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and -0.24 MPa, respectively, for the NE population and 254 mM and -0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha(-1) of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing) at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha(-1) followed by shallow flooding (2-cm depth) reduced seedling emergence by 94-96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85-100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses.

  5. Seed germination ecology of Echinochloa glabrescens and its implication for management in rice (Oryza sativa L.).

    PubMed

    Opeña, Jhoana L; Chauhan, Bhagirath S; Baltazar, Aurora M

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE) and Los Baños (IR)] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88%) from light stimulation than did the IR population (34%). The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and -0.24 MPa, respectively, for the NE population and 254 mM and -0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha(-1) of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing) at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha(-1) followed by shallow flooding (2-cm depth) reduced seedling emergence by 94-96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85-100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses. PMID:24642568

  6. Seed Germination Ecology of Echinochloa glabrescens and Its Implication for Management in Rice (Oryza sativa L.)

    PubMed Central

    Opeña, Jhoana L.; Chauhan, Bhagirath S.; Baltazar, Aurora M.

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE) and Los Baños (IR)] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88%) from light stimulation than did the IR population (34%). The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and −0.24 MPa, respectively, for the NE population and 254 mM and −0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha−1 of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing) at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha−1 followed by shallow flooding (2-cm depth) reduced seedling emergence by 94−96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85−100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses. PMID:24642568

  7. Does nitrogen saturation theory apply to unpolluted temperate forests? A test along a forest soil nitrogen gradient in Oregon

    NASA Astrophysics Data System (ADS)

    Perakis, S. S.; Sinkhorn, E. R.

    2011-12-01

    Natural gradients of soil nitrogen (N) can be used to evaluate the consequences of long-term ecosystem N enrichment, and to test the applicability of N saturation theory as a general framework for understanding ecosystem N dynamics. Temperate forest soils of the Oregon Coast Range experience low rates of atmospheric N deposition, yet display among the highest soil N accumulations ever reported worldwide. We measured plant and soil (0-1m) N stocks and natural abundance delta15N, plant production, N uptake and return in litterfall, soil gross and net N mineralization rates, and hydrologic N losses of nine Douglas-fir forests growing across an exceptionally wide soil N gradient in the Oregon Coast Range. Ecosystem N content ranged from 8,788 to 22,667 kg N/ha across sites, with highest N accumulations near the coast, and 96-98% of total ecosystem N residing in mineral soil. Ecosystem delta15N displayed a curvilinear relationship with ecosystem N content that reflected competing influences of N input from biological fixation at low-N sites and fractionating N losses at high-N sites. Simulation modeling of ecosystem N and delta15N mass balance suggest that cycles of wildfire can promote unusually high natural N accumulation by fostering early successional biological nitrogen fixation. Surface mineral soil (0 - 10 cm) N concentrations were tightly correlated to total soil N stocks to 1 m depth, and in contrast to predictions of N saturation theory, were linearly related to 10-fold variation in net N mineralization from 8 - 82 kg N/ha-yr. Net N mineralization was unrelated to soil C:N, soil texture, precipitation and temperature differences among sites. Net nitrification accounted for < 20% of net N mineralization at low N sites, increasing to 85 - 100% of net N mineralization at intermediate and high N sites, and was associated with soil pH decline from 5.8 to 4.1 across sites. The ratio of net:gross N mineralization and nitrification increased along the gradient

  8. Uptake of proline by the scutellum of germinating barley grain

    SciTech Connect

    Vaeisaenen, E.; Sopanen, T.

    1986-04-01

    Scutella separated from germinating grains of barley (Hordeum vulgare L. cv Himalaya) took up 1 millimolar L-(/sup 14/C)proline at an initial rate of about 6.5 micromoles gram/sup -1/ fresh weight hour/sup -1/ (pH 5, 30/sup 0/C). The uptake had a pH optimum at 5. The bulk of the uptake (93%) was via carrier-mediated active transport. All of the 19 L-amino acids tested at 10 millimolar concentration inhibited the mediated uptake of 1 millimolar proline, the inhibitions varying from 18 to 76%. By studying how large a fraction of the mediated uptake was inhibitable by asparagine, alanine, glutamine, and leucine, the mediated uptake was shown to be due to three components. Two of these are most probably attributable to the two nonspecific uptake systems proposed earlier to act in the uptake of glutamine and leucine. The third component was not inhibited by glutamine, asparagine, or alanine, but was inhibited by unlabeled proline and leucine. The uptake by this system was apparently carrier-mediated active transport. D-Proline inhibited this system as strongly as L-proline. Nine of the 16 L-amino tested at 50 millimolar concentrations did not inhibit the uptake of 1 millimolar proline by this system. Valine, leucine, isoleucine, and the basic amino acids were inhibitory, but in spite of this, they did not appear to be taken up by this system. It seems therefore that in addition to two nonspecific amino acid uptake systems the scutella have an uptake system which is specific for proline. It is likely that this proline-specific system accounts for the bulk of proline uptake in a germinating grain.

  9. Seed germination and root elongation as indicators of exposure of wetland seedlings to metals

    SciTech Connect

    Sutton, H.D.; Stokes, S.L.; Hook, D.D.; Klaine, S.J.

    1995-12-31

    Wetland ecosystems have often been impacted by the addition of hazardous waste materials. Methods are needed to evaluate the effect of these substances on wetland ecosystems and the organisms within them. This study evaluates the response of various wetland plant species to representative contaminants (cadmium, nickel, atrazine, anthracene, and tetrachloroethylene). Species tested include Caphalanthus occidentalis (buttonbush), Saururus cernuus (lizard`s tail), Liquidambar styraciflua (sweetgum), Sparganium americanum (bur-reed), and Fraxinus pennsylvanica (green ash). To the authors` knowledge these species have rarely if ever been used in toxicological assays. The endpoints used are germination and root elongation. Preliminary studies using a petri dish system have shown decreased germination at the highest metal concentration (50mg/L) and decreased root elongation in the higher metal concentrations (10, 25, and 50mg/L). Interference from the carrier was observed in the organic tests. Root elongation studies using the metals are being continued using tubes with various sand and vermiculite mixes into which freshly germinated seeds are placed. Species with the best responses will be tested in the field at the Savannah River Site, SC, and also with fuel oil. Lettuce (Lactuca saliva) and radish (Raphanus sativus) are being tested alongside the wetland species as reference organisms for which tests are well established.

  10. [Effects of exogenous Ca2+ on the seed germination of Koelreuteria paniculata in limestone area of Southwest China under drought stress].

    PubMed

    Cai, Xi-Yue; Chen, Xiao-De; Li, Chao-Zheng; Liu, Cheng

    2013-05-01

    In this paper, different arid environments in the limestone area of Southwest China were simulated by using different concentrations (0%, 5%, 15%, 25%, and 30%) of PEG6000 (polyethylene glycol), and a gradient of exogenous Ca2+ (0, 15, 20, 25, and 30 mmol x L(-1) of CaCl2) was installed to simulate the high calcium soil environments, aimed to study the effects of different concentration PEG6000, CaCl2, and their interactions on the seed germination characteristics of Koelreuteria bipinnata, one of the preferred species in the ecological restoration in limestone area. Under the action of CaCl2 alone, medium or low concentration exogenous Ca2+ had lesser effect on the seed germination parameters, but high concentration exogenous Ca2+ had inhibition effect on the seed germination. Medium or low concentration CaC12 could increase the seedling fresh biomass. When the PEG6000 concentration increased from 0% to 25%, the seed germination rate, germination potential, germination index, and vigor index showed a significant decreasing trend, and the seedling fresh biomass decreased remarkably. When certain concentration of exogenous Ca2+ was exerted to the drought treatment groups, medium or low concentration CaCl2 improved the seed germination characteristics, which compensated the loss from drought stress to a certain degree. When the CaCl2 concentration was up to 30 mmol x L(-1), the seeds were hard to germinate. Additionally, no seeds germinated under the condition of PEG with the concentration of 30%. It was suggested that applying definite concentration of exogenous Ca2+ could increase the seedling fresh biomass under PEG6000 stress, and make the seedlings more adapt to arid environment.

  11. Effect of different fertilizers on the germination and growth of velvetleaf (Abutilon theohrasti Medic.).

    PubMed

    Nagy, V; Nádasy, E

    2011-01-01

    Velvetleaf (Abutilon theophrasti Medic.) is one of the most important and invasive weed species in Hungary and also in Europe. Its dangerousness derives from its germination biology characteristics and its strong competitive and allelopathic ability. In wide line space crops such as corn, sunflower and soybean it may reduce the yield significantly, According to some authors, this yield reducing ability is lower with bigger nutrient supplies. Our experiment was carried in Keszthely, Hungary (46 degrees 45'35.53"; 17 degrees 14'26.9") at the Institute of Plant Protection, Georgikon Faculty, University of Pannonia in 2009 and 2010. We studied the separate and combined effect of different fertilizers on the germination and growth of velvetleaf in greenhouse pot experiments. The applied fertilizers were Linzer NAC (27% N) in doses of 200 kg N ha(-1) (2,325 g Linzer NAC/pot), Patent Káli (30% K2O) in 100 kg K2O ha(-1) (1,05g Patent Káli/pot) and DC Szuperfoszfát (20.5% P2O5) in 100 kg P2O5 ha(-1) (1,05g DC Szuperfoszfát/pot). Our study was carried out in 1.5-litre pots with Ramman brown-forest soil in four replications, with 25 seeds of velvetleaf per pots. Five velvetleaf plants were removed four and six weeks after planting from the pots and the lenght, the fresh- and the air dried weight and the leaf area of the plants was measured. The data were analyzed by ANOVA. We observed that nitrogen which was applied alone or with other nutrients can reduce the germination and growth of Abutilon with 200kg N ha(-1) doses. Potassium and phosphorus stimulate germination and growth. The biggest stimulating effect was produced by potassium when it was applied alone. PMID:22696961

  12. Germination and ROS detoxification in bell pepper (Capsicum annuum L.) under NaCl stress and treatment with microalgae extracts.

    PubMed

    Guzmán-Murillo, María A; Ascencio, Felipe; Larrinaga-Mayoral, Juan A

    2013-02-01

    We evaluated the salt tolerance of hybrids of pepper (Capsicum annuum L.) during germination. Treatments were applied at 0, 25, and 50 mM NaCl with preparations of supplemental extracts of the microalgae Dunaliella salina and Phaeodactylum tricornutum to determine the percentage germination rate as well as measured indicators of oxidative stress caused by the salt treatments during seed germination. We found that root growth was favorably influenced by the microalgae leading to increased germination rate. Tissues were analyzed in terms of superoxide radical production, lipid peroxidation, and activity of antioxidant enzymes viz. superoxide dismutase, catalase, and glutathione peroxidase. Our results suggest that application of microalgae extracts significantly reduced (p < 0.05) superoxide radical production, as well as lower lipid peroxidation in comparison to plants without extracts of microalgae. The antioxidant enzymes increased in the presence of microalgae showing a significant difference (p < 0.05). The results suggest differences in oxidative metabolism in response to the magnitude of salt stress and concentrations of microalgae help mitigate salt stress in plants during the germination process.

  13. Early quantitative method for measuring germination in non-green spores of Dryopteris paleacea using an epifluorescence-microscope technique

    NASA Technical Reports Server (NTRS)

    Scheuerlein, R.; Wayne, R.; Roux, S. J.

    1988-01-01

    A method is described to determine germination by blue-light excited red fluorescence in the positively photoblastic spores of Dryopteris paleacea Sw. This fluorescence is due to chlorophyll as evidenced from 1) a fluorescence-emission spectrum in vivo, where a bright fluorescence around 675 nm is obtained only in red light (R)-irradiated spores and 2) in vitro measurements with acetone extracts prepared from homogenized spores. Significant amounts of chlorophyll can be found only in R-treated spores; this chlorophyll exhibits an emission band around 668 nm, when irradiated with 430 nm light at 21 degrees C. Compared to other criteria for germination, such as swelling of the cell, coat splitting, greening, and rhizoid formation, which require longer periods after induction for their expression, chlorophyll fluorescence can be used to quantify germination after two days. This result is confirmed by fluence-response curves for R-induced spore germination; the same relationship between applied R and germination is obtained by the evaluation with the epifluorescence method 2 days after the light treatment as compared with the evaluation with bright-field microscopy 5 days after the inducing R. Using this technique we show for the first time that Ca2+ contributes to the signal-transduction chain in phytochrome-mediated chlorophyll synthesis in spores of Dryopteris paleacea.

  14. Up in smoke: II. Germination ofNicotiana attenuata in response to smoke-derived cues and nutrients in burned and unburned soils.

    PubMed

    Baldwin, I T; Morse, L

    1994-09-01

    Nicotiana attenuata is a native tobacco that is commonly found usually one growing season after fires in the blackbrush, sagebrush and pinyon-juniper forests of the Great Basin desert of North America. This plant also occurs in isolated dry washes and roadsides for many consecutive seasons. Postfire annuals are thought to synchronize their germination from the seed bank with the postfire environment in response to increases in (1) fire-related cues or (2) nutrient supply rates resulting from the mineralization of nutrients by fire, or (3) the removal of allelochemicals produced by the dominant vegetation occupying the sites before the burn or the microbial community associated with the dominant vegetation. We examine the effect of these three changes on the germination ofN. attenuata seed from artificial seed banks made with burned and unburned soil taken in 1993 from under four dominant shrub species (Coleogyne ramosissima, Yucca baccata, Lycium andersonnii, Purshia tridentata) of an area that burned in 1992 and from two dry washes in whichN. attenuata populations have persisted since at least 1988. We utilize our recent discovery that aqueous extracts of wood smoke contain potent germination cue(s) for this species and the established observation that nitrate stimulates germination in manyNicotiana species. In two experiments, we added smoke-derived germination cues and nutrients separately and in combinations to the artificial seed banks, measured germination rates, and inferred the effect of burning by the response of the seed banks to these additions. Germination rates of seed in burned soil were consistently higher than those in unburned soil collected from under all species tested; concentrations of nitrate, P, Mn, and Ca were also higher in burned than unburned soils. Because the addition of more cue and nitrate to burned soil increased germination rates, these soil components may not be at concentrations sufficient to saturate the germination response one

  15. Up in smoke: II. Germination ofNicotiana attenuata in response to smoke-derived cues and nutrients in burned and unburned soils.

    PubMed

    Baldwin, I T; Morse, L

    1994-09-01

    Nicotiana attenuata is a native tobacco that is commonly found usually one growing season after fires in the blackbrush, sagebrush and pinyon-juniper forests of the Great Basin desert of North America. This plant also occurs in isolated dry washes and roadsides for many consecutive seasons. Postfire annuals are thought to synchronize their germination from the seed bank with the postfire environment in response to increases in (1) fire-related cues or (2) nutrient supply rates resulting from the mineralization of nutrients by fire, or (3) the removal of allelochemicals produced by the dominant vegetation occupying the sites before the burn or the microbial community associated with the dominant vegetation. We examine the effect of these three changes on the germination ofN. attenuata seed from artificial seed banks made with burned and unburned soil taken in 1993 from under four dominant shrub species (Coleogyne ramosissima, Yucca baccata, Lycium andersonnii, Purshia tridentata) of an area that burned in 1992 and from two dry washes in whichN. attenuata populations have persisted since at least 1988. We utilize our recent discovery that aqueous extracts of wood smoke contain potent germination cue(s) for this species and the established observation that nitrate stimulates germination in manyNicotiana species. In two experiments, we added smoke-derived germination cues and nutrients separately and in combinations to the artificial seed banks, measured germination rates, and inferred the effect of burning by the response of the seed banks to these additions. Germination rates of seed in burned soil were consistently higher than those in unburned soil collected from under all species tested; concentrations of nitrate, P, Mn, and Ca were also higher in burned than unburned soils. Because the addition of more cue and nitrate to burned soil increased germination rates, these soil components may not be at concentrations sufficient to saturate the germination response one

  16. Conserved transcriptional regulatory programs underlying rice and barley germination.

    PubMed

    Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang Charles

    2014-01-01

    Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

  17. Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

    PubMed Central

    Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

    2014-01-01

    Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

  18. Photocontrol of the Germination of Onoclea Spores

    PubMed Central

    Towill, Leslie R.; Ikuma, Hiroshi

    1975-01-01

    The changes in levels of metabolites during photoinduced germination of Onoclea sensibilis L. spores are described. Proteins and lipids, which constitute 25 and 20%, respectively, of the unimbibed spores on a dry weight basis, are hydrolyzed at the time of differentiation and elongation of the germling cells and may be utilized for these processes. Sucrose degradation, starch synthesis, and active respiration occur during dark imbibition, but these processes are accelerated by red or far red irradiation. Endogenous sucrose is the probable source of the carbon skeleton for starch synthesis. PMID:16659327

  19. Factors affecting spore germination in algae - review.

    PubMed

    Agrawal, S C

    2009-01-01

    This review surveys whatever little is known on the influence of different environmental factors like light, temperature, nutrients, chemicals (such as plant hormones, vitamins, etc.), pH of the medium, biotic factors (such as algal extracellular substances, algal concentration, bacterial extracellular products, animal grazing and animal extracellular products), water movement, water stress, antibiotics, UV light, X-rays, gamma-rays, and pollution on the spore germination in algae. The work done on the dormancy of algal spores and on the role of vegetative cells in tolerating environmental stress is also incorporated. PMID:19826917

  20. Effect of Essential Oils on Germination and Growth of Some Pathogenic and Spoilage Spore-Forming Bacteria.

    PubMed

    Voundi, Stève Olugu; Nyegue, Maximilienne; Lazar, Iuliana; Raducanu, Dumitra; Ndoye, Florentine Foe; Marius, Stamate; Etoa, François-Xavier

    2015-06-01

    The use of essential oils as a food preservative has increased due to their capacity to inhibit vegetative growth of some bacteria. However, only limited data are available on their effect on bacterial spores. The aim of the present study was to evaluate the effect of some essential oils on the growth and germination of three Bacillus species and Geobacillus stearothermophilus. Essential oils were chemically analyzed using gas chromatography and gas chromatography coupled to mass spectrometry. The minimal inhibitory and bactericidal concentrations of vegetative growth and spore germination were assessed using the macrodilution method. Germination inhibitory effect of treated spores with essential oils was evaluated on solid medium, while kinetic growth was followed using spectrophotometry in the presence of essential oils. Essential oil from Drypetes gossweileri mainly composed of benzyl isothiocyanate (86.7%) was the most potent, with minimal inhibitory concentrations ranging from 0.0048 to 0.0097 mg/mL on vegetative cells and 0.001 to 0.002 mg/mL on spore germination. Furthermore, essential oil from D. gossweileri reduced 50% of spore germination after treatment at 1.25 mg/mL, and its combination with other oils improved both bacteriostatic and bactericidal activities with additive or synergistic effects. Concerning the other essential oils, the minimal inhibitory concentration ranged from 5 to 0.63 mg/mL on vegetative growth and from 0.75 to 0.09 mg/mL on the germination of spores. Spectrophotometric evaluation showed an inhibitory effect of essential oils on both germination and outgrowth. From these results, it is concluded that some of the essential oils tested might be a valuable tool for bacteriological control in food industries. Therefore, further research regarding their use as food preservatives should be carried out.

  1. Effect of Essential Oils on Germination and Growth of Some Pathogenic and Spoilage Spore-Forming Bacteria.

    PubMed

    Voundi, Stève Olugu; Nyegue, Maximilienne; Lazar, Iuliana; Raducanu, Dumitra; Ndoye, Florentine Foe; Marius, Stamate; Etoa, François-Xavier

    2015-06-01

    The use of essential oils as a food preservative has increased due to their capacity to inhibit vegetative growth of some bacteria. However, only limited data are available on their effect on bacterial spores. The aim of the present study was to evaluate the effect of some essential oils on the growth and germination of three Bacillus species and Geobacillus stearothermophilus. Essential oils were chemically analyzed using gas chromatography and gas chromatography coupled to mass spectrometry. The minimal inhibitory and bactericidal concentrations of vegetative growth and spore germination were assessed using the macrodilution method. Germination inhibitory effect of treated spores with essential oils was evaluated on solid medium, while kinetic growth was followed using spectrophotometry in the presence of essential oils. Essential oil from Drypetes gossweileri mainly composed of benzyl isothiocyanate (86.7%) was the most potent, with minimal inhibitory concentrations ranging from 0.0048 to 0.0097 mg/mL on vegetative cells and 0.001 to 0.002 mg/mL on spore germination. Furthermore, essential oil from D. gossweileri reduced 50% of spore germination after treatment at 1.25 mg/mL, and its combination with other oils improved both bacteriostatic and bactericidal activities with additive or synergistic effects. Concerning the other essential oils, the minimal inhibitory concentration ranged from 5 to 0.63 mg/mL on vegetative growth and from 0.75 to 0.09 mg/mL on the germination of spores. Spectrophotometric evaluation showed an inhibitory effect of essential oils on both germination and outgrowth. From these results, it is concluded that some of the essential oils tested might be a valuable tool for bacteriological control in food industries. Therefore, further research regarding their use as food preservatives should be carried out. PMID:25884442

  2. Effects of soil contamination by trace elements on white poplar progeny: seed germination and seedling vigour.

    PubMed

    Madejón, Paula; Cantos, Manuel; Jiménez-Ramos, María C; Marañón, Teodoro; Murillo, José M

    2015-11-01

    Seed germination is considered a critical phase in plant development and relatively sensitive to heavy metals. White poplar (Populus alba) trees tend to accumulate Cd and Zn in their tissues. We tested if soil contamination can affect P. alba progeny, reduced seed germination and explored the distribution of mineral elements in the seed. For this purpose, fruits and seeds from female P. alba trees were selected from two contaminated and one non-contaminated areas. Seeds from all the sites were germinated using only water or a nutritive solution (in vitro). Concentrations of nutrients and trace elements in the fruits and seeds were analysed. Seedling growth in vitro was also analysed. Finally, a mapping of different elements within the poplar seed was obtained by particle-induced X-ray emission (PIXE). Germination was similar between different progenies, refuting our hypothesis that seeds from a contaminated origin would have reduced germination capacity compared to those from a non-contaminated site. Seedling growth was not affected by the contaminated origin. Cadmium and Zn concentrations in fruits produced by P. alba trees in the contaminated sites were higher than by those from the non-contaminated site. However, the nutritional status of the trees was adequate in both cases. Cd in seedlings was higher in those from contaminated soils although lower than in fruits, indicating a certain exclusion from seeds. Preliminary results of the PIXE technique showed that Al and Zn were distributed uniformly in the seeds (Cd was not detected with this technique), while the nutrients P and S were concentrated in the cotyledons.

  3. Mycorrhizal fungi of Vanilla: diversity, specificity and effects on seed germination and plant growth.

    PubMed

    Porras-Alfaro, Andrea; Bayman, Paul

    2007-01-01

    Mycorrhizal fungi are essential for the germination of orchid seeds. However, the specificity of orchids for their mycorrhizal fungi and the effects of the fungi on orchid growth are controversial. Mycorrhizal fungi have been studied in some temperate and tropical, epiphytic orchids, but the symbionts of tropical, terrestrial orchids are still unknown. Here we study diversity, specificity and function of mycorrhizal fungi in Vanilla, a pantropical genus that is both terrestrial and epiphytic. Mycorrhizal roots were collected from four Vanilla species in Puerto Rico, Costa Rica and Cuba. Cultured and uncultured mycorrhizal fungi were identified by sequencing the internal transcribed spacer region of nuclear rDNA (nrITS) and part of the mitochondrial ribosomal large subunit (mtLSU), and by counting number of nuclei in hyphae. Vanilla spp. were associated with a wide range of mycorrhizal fungi: Ceratobasidium, Thanatephorus and Tulasnella. Related fungi were found in different species of Vanilla, although at different relative frequencies. Ceratobasidium was more common in roots in soil and Tulasnella was more common in roots on tree bark, but several clades of fungi included strains from both substrates. Relative frequencies of genera of mycorrhizal fungi differed significantly between cultured fungi and those detected by direct amplification. Ceratobasidium and Tulasnella were tested for effects on seed germination of Vanilla and effects on growth of Vanilla and Dendrobium plants. We found significant differences among fungi in effects on seed germination and plant growth. Effects of mycorrhizal fungi on Vanilla and Dendrobium were similar: a clade of Ceratobasidium had a consistently positive effect on plant growth and seed germination. This clade has potential use in germination and propagation of orchids. Results confirmed that a single orchid species can be associated with several mycorrhizal fungi with different functional consequences for the plant.

  4. Incorporating Cache Management Behavior into Seed Dispersal: The Effect of Pericarp Removal on Acorn Germination

    PubMed Central

    Yi, Xianfeng; Zhang, Mingming; Bartlow, Andrew W.; Dong, Zhong

    2014-01-01

    Selecting seeds for long-term storage is a key factor for food hoarding animals. Siberian chipmunks (Tamias sibiricus) remove the pericarp and scatter hoard sound acorns of Quercus mongolica over those that are insect-infested to maximize returns from caches. We have no knowledge of whether these chipmunks remove the pericarp from acorns of other species of oaks and if this behavior benefits seedling establishment. In this study, we tested whether Siberian chipmunks engage in this behavior with acorns of three other Chinese oak species, Q. variabilis, Q. aliena and Q. serrata var. brevipetiolata, and how the dispersal and germination of these acorns are affected. Our results show that when chipmunks were provided with sound and infested acorns of Quercus variabilis, Q. aliena and Q. serrata var. brevipetiolata, the two types were equally harvested and dispersed. This preference suggests that Siberian chipmunks are incapable of distinguishing between sound and insect-infested acorns. However, Siberian chipmunks removed the pericarp from acorns of these three oak species prior to dispersing and caching them. Consequently, significantly more sound acorns were scatter hoarded and more infested acorns were immediately consumed. Additionally, indoor germination experiments showed that pericarp removal by chipmunks promoted acorn germination while artificial removal showed no significant effect. Our results show that pericarp removal allows Siberian chipmunks to effectively discriminate against insect-infested acorns and may represent an adaptive behavior for cache management. Because of the germination patterns of pericarp-removed acorns, we argue that the foraging behavior of Siberian chipmunks could have potential impacts on the dispersal and germination of acorns from various oak species. PMID:24647670

  5. Effects of soil contamination by trace elements on white poplar progeny: seed germination and seedling vigour.

    PubMed

    Madejón, Paula; Cantos, Manuel; Jiménez-Ramos, María C; Marañón, Teodoro; Murillo, José M

    2015-11-01

    Seed germination is considered a critical phase in plant development and relatively sensitive to heavy metals. White poplar (Populus alba) trees tend to accumulate Cd and Zn in their tissues. We tested if soil contamination can affect P. alba progeny, reduced seed germination and explored the distribution of mineral elements in the seed. For this purpose, fruits and seeds from female P. alba trees were selected from two contaminated and one non-contaminated areas. Seeds from all the sites were germinated using only water or a nutritive solution (in vitro). Concentrations of nutrients and trace elements in the fruits and seeds were analysed. Seedling growth in vitro was also analysed. Finally, a mapping of different elements within the poplar seed was obtained by particle-induced X-ray emission (PIXE). Germination was similar between different progenies, refuting our hypothesis that seeds from a contaminated origin would have reduced germination capacity compared to those from a non-contaminated site. Seedling growth was not affected by the contaminated origin. Cadmium and Zn concentrations in fruits produced by P. alba trees in the contaminated sites were higher than by those from the non-contaminated site. However, the nutritional status of the trees was adequate in both cases. Cd in seedlings was higher in those from contaminated soils although lower than in fruits, indicating a certain exclusion from seeds. Preliminary results of the PIXE technique showed that Al and Zn were distributed uniformly in the seeds (Cd was not detected with this technique), while the nutrients P and S were concentrated in the cotyledons. PMID:26433900

  6. In Situ Histochemical Localisation of Alkaloids and Acetogenins in the Endosperm and Embryonic Axis of Annona Macroprophyllata Donn. Sm. Seeds During Germination

    PubMed Central

    Brechú-Franco, A.E.; Laguna-Hernández, G.; De la Cruz-Chacón, I.; González-Esquinca, A.R.

    2016-01-01

    Currently, the Annonaceae family is characterised by the production of acetogenins (ACGs), and also by the biosynthesis of alkaloids, primarily benzylisoquinolines derived from tyrosine. The objective of this study was to confirm the presence of alkaloids and acetogenins in the idioblasts of the endosperm and the embryonic axis of A. macroprophyllata seeds in germination. The Dragendorff, Dittmar, Ellram, and Lugol reagents were used to test for alkaloids, and Kedde’s reagent was used to determine the presence of acetogenins in fresh sections of the endosperm and embryonic axis of seeds after twelve days of germination. A positive reaction was observed for all the reagents, and the presence of alkaloids and acetogenins was confirmed in the idioblasts of the endosperm and those involved in the differentiation of the embryonic axis of the developing seedling. We concluded that the idioblasts store both metabolites, acetogenins and alkaloids. Beginning at differentiation, the idioblasts of the embryonic axis simultaneously biosynthesise acetogenins and alkaloids that are characteristic of the species during the development of the seedling. The method used here can be applied to histochemically confirm the presence of acetogenins and alkaloids in tissues and structures of the plant in different stages of its life cycle. PMID:26972713

  7. Effect of some commonly used pesticides on seed germination, biomass production and photosynthetic pigments in tomato (Lycopersicon esculentum).

    PubMed

    Shakir, Shakirullah Khan; Kanwal, Memoona; Murad, Waheed; Zia ur Rehman; Shafiq ur Rehman; Daud, M K; Azizullah, Azizullah

    2016-03-01

    Pesticides are highly toxic substances. Their toxicity may not be absolutely specific to the target organisms but can adversely affect different processes in the non-target host plants. In the present study, the effect of over application of four commonly used pesticides (emamectin benzoate, alpha-cypermethrin, lambda-cyhalothrin and imidacloprid) was evaluated on the germination, seedling vigor and photosynthetic pigments in tomato. The obtained results revealed that seed germination was decreased by the pesticides and this effect was more prominent at early stages of exposure. All the tested pesticides reduced the growth of tomato when applied in higher concentration than the recommended dose, but at lower doses the pesticides had some stimulatory effects on growth as compared to the control. A similar effect of pesticides was observed on the photosynthetic pigments, i.e. a decrease in pigments concentrations was caused at higher doses but an increase was observed at lower doses of pesticides. The calculation of EC50 values for different parameters revealed the lowest EC50 values for emamectin (ranged as 51-181 mg/L) followed by alpha-cypermethrin (191.74-374.39), lambda-cyhalothrin (102.43-354.28) and imidacloprid (430.29-1979.66 mg/L). A comparison of the obtained EC50 values for different parameters of tomato with the recommended doses revealed that over application of these pesticides can be harmful to tomato crop. In a few cases these pesticides were found toxic even at the recommended doses. However, a field based study in this regard should be conducted to further verify these results.

  8. Rice (Oryza sativa L.) Seed Sterilization and Germination Enhancement via Atmospheric Hybrid Nonthermal Discharge Plasma.

    PubMed

    Khamsen, Natthaporn; Onwimol, Damrongvudhi; Teerakawanich, Nithiphat; Dechanupaprittha, Sanchai; Kanokbannakorn, Weerawoot; Hongesombut, Komsan; Srisonphan, Siwapon

    2016-08-01

    We designed a system to produce atmospheric hybrid cold-discharge plasma (HCP) based on microcorona discharge on a single dielectric barrier and applied it to inactivate microorganisms that commonly attach the rice seed husk. The cold-plasma treatment modified the surface of the rice seeds, resulting in accelerated germination and enhanced water imbibition. The treatment can operate under air-based ambient conditions without the need for a vacuum. The cold-plasma treatment completely inactivated pathogenic fungi and other microorganisms, enhancing the germination percentage and seedling quality. The final germination percentage of the treated rice seeds was ∼98%, whereas that of the nontreated seeds was ∼90%. Microcorona discharge on a single dielectric barrier provides a nonaggressive cold plasma that can be applied to organic materials without causing thermal and electrical damage. The hybrid nonthermal plasma is cost effective and consumes relatively little power, making it suitable for the surface sterilization and disinfection of organic and biological materials with large-scale compatibility. PMID:27404121

  9. Rice (Oryza sativa L.) Seed Sterilization and Germination Enhancement via Atmospheric Hybrid Nonthermal Discharge Plasma.

    PubMed

    Khamsen, Natthaporn; Onwimol, Damrongvudhi; Teerakawanich, Nithiphat; Dechanupaprittha, Sanchai; Kanokbannakorn, Weerawoot; Hongesombut, Komsan; Srisonphan, Siwapon

    2016-08-01

    We designed a system to produce atmospheric hybrid cold-discharge plasma (HCP) based on microcorona discharge on a single dielectric barrier and applied it to inactivate microorganisms that commonly attach the rice seed husk. The cold-plasma treatment modified the surface of the rice seeds, resulting in accelerated germination and enhanced water imbibition. The treatment can operate under air-based ambient conditions without the need for a vacuum. The cold-plasma treatment completely inactivated pathogenic fungi and other microorganisms, enhancing the germination percentage and seedling quality. The final germination percentage of the treated rice seeds was ∼98%, whereas that of the nontreated seeds was ∼90%. Microcorona discharge on a single dielectric barrier provides a nonaggressive cold plasma that can be applied to organic materials without causing thermal and electrical damage. The hybrid nonthermal plasma is cost effective and consumes relatively little power, making it suitable for the surface sterilization and disinfection of organic and biological materials with large-scale compatibility.

  10. Investigating the Influence of Karrikins on Seed Germination

    ERIC Educational Resources Information Center

    de Beer, Josef

    2012-01-01

    Recent research has identified a karrikin (a butenolide derative) known as 3-methyl-2H-furo[2,3-c]pyran-2-one, formed from burning cellulose, that stimulates seed germination. Here, I present ideas on how to investigate the influence of karrikins on seed germination in the laboratory.

  11. The importance of seed germination in rangeland research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA, Agricultural Research Service (ARS)/ Great Basin Rangelands Research Unit, Wildland Seed Laboratory, located in Reno, NV, has been studying seed germination for the past 40 years. The wildland seed laboratory has collected, processed, and quantified germination characteristics of hundreds...

  12. Radish (Raphanus sativus) seed size affects germination response to coumarin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inhibition of seed germination by an allelochemical is generally greater in small seeds than in large seeds. Studies reporting these results used a large number of plant species that varied in seed size, which might have introduced differences in germination characteristics or various parameter...

  13. Seed germination of five Poa species at negative water potentials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under field conditions water is often inadequate for satisfactory seed germination. An experiment was conducted to determine the effects of simulated dry conditions on germination and seedling growth of five bluegrass (Poa) species including: Texas, P. arachnifera Torr.; annual, P. annua L.; mutto...

  14. Lipids stimulate spore germination in the entomopathogenic ascomycete Ascosphaera aggregata.

    PubMed

    James, R R; Buckner, J S

    2004-10-01

    The alfalfa leafcutting bee (Megachile rotundata) is solitary and managed on a large scale for pollination of alfalfa seed crops. The bees nest in holes drilled in wood or polystyrene blocks, and their larvae are highly prone to a fungal disease called chalkbrood. The most prevalent form of chalkbrood is caused by Ascosphaera aggregata, but this ascomycete is difficult to culture. Hyphae will grow on standard fungal media, but spore germination is difficult to achieve and highly variable. We found that germination can be enhanced with oils. Lipids derived from plants and bee larvae increased germination from 50% (without oil) to 75-85% (with oil). Percent germination was significantly greater in the presence of lipids but germination was not significantly different when different oils, including mineral oil, were used. A. aggregata spores oriented along the oil-aqueous interface in the broth in a polar fashion, with swelling and germ tube formation always occurring into the aqueous portion of the broth. The other half of the spore tended to attach to a lipid droplet, where it remained, without swelling, during germ tube formation. The physical attachment of spores to the oil-aqueous interface is what most probably stimulates spore germination, as opposed to some nutritional stimulation. However, further research is needed to determine if and where the spores encounter such an interface when germinating in the host gut, where germination normally occurs. PMID:15645171

  15. Role of ethylene in the germination metabolism of ricinus communis

    NASA Astrophysics Data System (ADS)

    Cristescu, Simona; Dumitras, Dan C.; Godeanu, Adriana

    1999-03-01

    A CO2 laser-based photoacoustic method has been used to monitor the ethylene (C2H4) released by castor bean (Ricinus communis) seeds during germination. The relationship between the evolution of the C2H4 germinating seeds and the respiration intensity is presented.

  16. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination

    PubMed Central

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions. PMID:27446159

  17. The pleiotropic effects of the seed germination inhibitor germostatin.

    PubMed

    Ye, Yajin; Zhao, Yang

    2016-01-01

    Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phytohormone that induces seed dormancy. We have recently shown that germonstatin (GS), a small synthetic molecule identified by high through-put chemical genetic screenings, inhibits seed germination through up-regulating auxin signaling and inducing auxin biosynthesis. GERMOSTATIN RESISTANCE LOCUS 1 (GSR1) encodes a plant homeodomain (PHD) finger protein and is responsible for GS seed germination inhibition. Its knockdown mutant gsr1 displays decreased dormancy. In this report, we show that GS is not an ABA analog and provided 2 other GS-resistant mutants related to the chemical's function in seed germination inhibition other than gsr1, suggesting that GS may have pleiotropic effects through targeting different pathway governing seed germination.

  18. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination.

    PubMed

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions.

  19. Study for Germination Under Extreme Hypobaric and Hypoxic Condition

    NASA Astrophysics Data System (ADS)

    Hashimoto, H.

    2010-04-01

    In order to investigate a possibility of plant cultivation for the space agriculture on Mars, germination rate for six species of plant under extreme hypobaric and hypoxic condition was measured. As a result, seeds of Jute and Cucumber were able to germinate in six species.

  20. The pleiotropic effects of the seed germination inhibitor germostatin.

    PubMed

    Ye, Yajin; Zhao, Yang

    2016-01-01

    Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phytohormone that induces seed dormancy. We have recently shown that germonstatin (GS), a small synthetic molecule identified by high through-put chemical genetic screenings, inhibits seed germination through up-regulating auxin signaling and inducing auxin biosynthesis. GERMOSTATIN RESISTANCE LOCUS 1 (GSR1) encodes a plant homeodomain (PHD) finger protein and is responsible for GS seed germination inhibition. Its knockdown mutant gsr1 displays decreased dormancy. In this report, we show that GS is not an ABA analog and provided 2 other GS-resistant mutants related to the chemical's function in seed germination inhibition other than gsr1, suggesting that GS may have pleiotropic effects through targeting different pathway governing seed germination. PMID:26918467

  1. The pleiotropic effects of the seed germination inhibitor germostatin

    PubMed Central

    Ye, Yajin; Zhao, Yang

    2016-01-01

    ABSTRACT Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phytohormone that induces seed dormancy. We have recently shown that germonstatin (GS), a small synthetic molecule identified by high through-put chemical genetic screenings, inhibits seed germination through up-regulating auxin signaling and inducing auxin biosynthesis. GERMOSTATIN RESISTANCE LOCUS 1 (GSR1) encodes a plant homeodomain (PHD) finger protein and is responsible for GS seed germination inhibition. Its knockdown mutant gsr1 displays decreased dormancy. In this report, we show that GS is not an ABA analog and provided 2 other GS-resistant mutants related to the chemical's function in seed germination inhibition other than gsr1, suggesting that GS may have pleiotropic effects through targeting different pathway governing seed germination. PMID:26918467

  2. Mitochondrial biogenesis in plants during seed germination.

    PubMed

    Law, Simon R; Narsai, Reena; Whelan, James

    2014-11-01

    Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination. PMID:24727594

  3. Impact of hydrocarbons from a diesel fuel on the germination and early growth of subantarctic plants.

    PubMed

    Macoustra, Gabriella K; King, Catherine K; Wasley, Jane; Robinson, Sharon A; Jolley, Dianne F

    2015-07-01

    Special Antarctic Blend (SAB) is a diesel fuel dominated by aliphatic hydrocarbons that is commonly used in Antarctic and subantarctic regions. The past and present use of SAB fuel at Australia's scientific research stations has resulted in multiple spills, contaminating soils in these pristine areas. Despite this, no soil quality guidelines or remediation targets have been developed for the region, primarily due to the lack of established indigenous test species and subsequent biological effects data. In this study, twelve plant species native to subantarctic regions were collected from Macquarie Island and evaluated to determine their suitably for use in laboratory-based toxicity testing, using germination success and seedling growth (shoot and root length) as endpoints. Two soil types (low and high organic carbon (OC)) were investigated to reflect the variable OC content found in soils on Macquarie Island. These soils were spiked with SAB fuel and aged for 14 days to generate a concentration series of SAB-contaminated soils. Exposure doses were quantified as the concentration of total petroleum hydrocarbons (TPH, nC9-nC18) on a soil dry mass basis. Seven species successfully germinated on control soils under laboratory conditions, and four of these species (Colobanthus muscoides Hook.f., Deschampsia chapmanii Petrie, Epilobium pendunculare A.Cunn. and Luzula crinita Hook.f.) showed a dose-dependent inhibition of germination when exposed to SAB-contaminated soils. Contaminated soils with low OC were generally more toxic to plants than high organic carbon soils. Increasing soil-TPH concentrations significantly inhibited shoot and root growth, and root length was identified as the most sensitive endpoint. Although the test species were tolerant to SAB-contaminated soils in germination assays, development of early life stages (up to 28 days) were generally more sensitive indicator of exposure effects, and may be more useful endpoints for future testing.

  4. Coordination of seed dormancy and germination processes by MYB96.

    PubMed

    Lee, Kyounghee; Seo, Pil Joon

    2015-01-01

    The transition between seed dormancy and germination is an important stage that initiates plant life cycle. Hormonal balances of abscisic acid (ABA) and gibberellin (GA) contribute to determining the proper timing to germinate. Here, we demonstrate that the R2R3-type MYB96 transcription factor, a key ABA signaling mediator, coordinates seed dormancy and germination processes through distinct downstream events. This transcription factor controls ABA-INSENSITIVE 4 (ABI4) expression to inhibit seed germination by suppressing breakdown of lipid reserves in embryo. In addition, it also induces seed dormancy by stimulating ABA biosynthesis in an ABI4-independent manner. We propose that MYB96 integrates a multitude of environmental stress signals and acts as a master regulator in the determination of timing for seed germination.

  5. Trace gas emissions and smoke-induced seed germination

    SciTech Connect

    Keeley, J.E.; Fotheringham, C.J.

    1997-05-23

    Dormant seeds of a California chaparral annual were induced to germinate by smoke or paper. Nitrogen oxides induced 100 percent vapors emitted from smoke-treated sand or treated water samples inducing. Smoke germination in a manner similar to smoke germination were comparable in acidity and concentration of nitrate and nitrite to nitrogen dioxide (NO{sub 2})-treated samples. Vapors from smoke-treated and NO{sub 2}-treated filter paper had comparable NO{sub 2} flux rates. Chaparral wildfires generate sufficient nitrogen oxides from combustion of organic matter or from postfire biogenic nitrification to trigger germination of Emmerianthe penduliflora. Nitrogen oxide-triggered germination is not the result of changes in imbibition, as is the case with heat stimulated seeds.

  6. Photoperiodic control of germination in the unicell Chlamydomonas

    NASA Astrophysics Data System (ADS)

    Suzuki, Lena; Johnson, Carl Hirschie

    2002-03-01

    Photoperiodic time measurement is a well-documented adaptation of multicellular plants and animals to seasonal changes in the environment, but it is unclear whether unicellular organisms can exhibit bona fide photoperiodic responses. We demonstrate that the occurrence of zygospore germination of the unicellular alga Chlamydomonas is a genuine photoperiodic response. Germination efficiency is enhanced in long days as compared with short days. While the total amount of light exposure influences the efficiency of germination, the photoperiod is a significant cue for germination. The developmental stage that senses the photoperiod is just prior to mating and during the first days of zygospore development, so there may be a critical window of zygospore maturation that is regulated by photoperiod. Because zygospores are resistant to freezing injury, whereas vegetative cells are not, it is likely that the suppression of germination by short days is an adaptive response for overwintering of Chlamydomonas. Therefore, Chlamydomonas is a single-celled organism that is capable of photoperiodic responses.

  7. Enhancement of germination rate of aged seeds by ethylene.

    PubMed

    Takayanagi, K; Harrington, J F

    1971-04-01

    Naturally and artificially aged seeds of rape, Brassica napus L., produced less ethylene than freshly harvested seed during the early stage of germination. With freshly harvested seeds one peak of ethylene production was observed during germination, which coincided with the emergence and elongation of root and cotyledon, accompanied by splitting of the seed coat. Application of exogenous ethylene was effective in accelerating germination in aged seeds but did not significantly improve the percentage of germination. Ethylene as a hormone was considered to serve as a stimulator of germination and growth. One of the factors causing seed aging might be the degeneration of an ethylene-producing system in the seed. Exogenous ethylene may be effective only for the seeds in which the ethylene-producing system is weakened but the following responding systems are still functional.

  8. Development of a cell line from Echinococcus granulosus germinal layer.

    PubMed

    Albani, Clara María; Cumino, Andrea Carina; Elissondo, María Celina; Denegri, Guillermo María

    2013-10-01

    In vitro culture of parasitic helminths provides an important tool to study cell regeneration and physiology, as well as for molecular biology and genetic engineering studies. In the present study, we established in vitro propagation of cells from Echinococcus granulosus germinal cyst layer. E. granulosus germinal cells grew beyond 100 passages and showed no signs of reduced proliferation capacity. Microscopic analysis revealed that cells grew both attached to the substrate and in suspension, forming three-dimensional structures like mammalian stem cell aggregates. Examination of the chromosome number of attached germinal cells showed a high degree of heteroploidy, suggesting the occurrence of transformation during culture. Monolayer cells survived cryopreservation and were able to proliferate after thawing. Based on the characteristics displayed by E. granulosus germinal cells, we establish a cell line from the E. granulosus germinal layer. Furthermore, we propose that this cell line could be useful for drug screening and for obtaining parasite material.

  9. Coordination of seed dormancy and germination processes by MYB96

    PubMed Central

    Lee, Kyounghee; Seo, Pil Joon

    2015-01-01

    The transition between seed dormancy and germination is an important stage that initiates plant life cycle. Hormonal balances of abscisic acid (ABA) and gibberellin (GA) contribute to determining the proper timing to germinate. Here, we demonstrate that the R2R3-type MYB96 transcription factor, a key ABA signaling mediator, coordinates seed dormancy and germination processes through distinct downstream events. This transcription factor controls ABA-INSENSITIVE 4 (ABI4) expression to inhibit seed germination by suppressing breakdown of lipid reserves in embryo. In addition, it also induces seed dormancy by stimulating ABA biosynthesis in an ABI4-independent manner. We propose that MYB96 integrates a multitude of environmental stress signals and acts as a master regulator in the determination of timing for seed germination. PMID:26313409

  10. Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.)

    PubMed Central

    Tian, Yu; Guan, Bo; Zhou, Daowei; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method. PMID:25093210

  11. Rapid Germination of a Barley Mutant Is Correlated with a Rapid Turnover of Abscisic Acid Outside the Embryo.

    PubMed

    Visser, K.; Vissers, APA.; Cagirgan, M. I.; Kijne, J. W.; Wang, M.

    1996-08-01

    In our study of the role of abscisic acid (ABA) in controlling the germination of barley grains, we tested a barley mutant line with a gigantum appearance (Hordeum distichum cv Quantum) for an ABA-insensitive phenotype by assaying germination in the presence of 10-4 M ABA. Dissected embryos of the mutant germinated at least 10 h earlier than did those of the wild type. The half-maximal concentrations of ABA inhibitory for germination were determined to be 5 x 10-4 M for the mutant and 10-6 M for the wild type. Expression of an ABA-induced Rab gene was studied to determine ABA responsiveness. The ABA concentration required for a half-maximal induction of Rab gene expression was 4 x 10-6 M in isolated embryos of both the mutant and wild type. This result suggests that ABA signal transduction pathways were not affected in the mutant. When isolated embryos were allowed to imbibe in water, ABA was released from the mutant and wild-type embryos at the same rate. However, the free ABA level in the incubation medium of the mutant showed a much faster decrease than that of the wild type, as demonstrated by two independent ABA assay methods (high-performance liquid chromatography and enzyme-linked immunosorbent assay). Our results suggest that turnover of ABA outside the embryo is a determining factor in the germination of barley seeds.

  12. Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

    PubMed

    Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

  13. Association mapping of soybean seed germination under salt stress.

    PubMed

    Kan, Guizhen; Zhang, Wei; Yang, Wenming; Ma, Deyuan; Zhang, Dan; Hao, Derong; Hu, Zhenbin; Yu, Deyue

    2015-12-01

    Soil salinity is a serious threat to agriculture sustainability worldwide. Seed germination is a critical phase that ensures the successful establishment and productivity of soybeans in saline soils. However, little information is available regarding soybean salt tolerance at the germination stage. The objective of this study was to identify the genetic mechanisms of soybean seed germination under salt stress. One natural population consisting of 191 soybean landraces was used in this study. Soybean seeds produced in four environments were used to evaluate the salt tolerance at their germination stage. Using 1142 single-nucleotide polymorphisms (SNPs), the molecular markers associated with salt tolerance were detected by genome-wide association analysis. Eight SNP-trait associations and 13 suggestive SNP-trait associations were identified using a mixed linear model and the TASSEL 4.0 software. Eight SNPs or suggestive SNPs were co-associated with two salt tolerance indices, namely (1) the ratio of the germination index under salt conditions to the germination index under no-salt conditions (ST-GI) and (2) the ratio of the germination rate under salt conditions to the germination rate under no-salt conditions (ST-GR). One SNP (BARC-021347-04042) was significantly associated with these two traits (ST-GI and ST-GR). In addition, nine possible candidate genes were located in or near the genetic region where the above markers were mapped. Of these, five genes, Glyma08g12400.1, Glyma08g09730.1, Glyma18g47140.1, Glyma09g00460.1, and Glyma09g00490.3, were verified in response to salt stress at the germination stage. The SNPs detected could facilitate a better understanding of the genetic basis of soybean salt tolerance at the germination stage, and the marker BARC-021347-04042 could contribute to future breeding for soybean salt tolerance by marker-assisted selection.

  14. Chemical investigation of Cyperus distans L. and inhibitory activity of scabequinone in seed germination and seedling growth bioassays.

    PubMed

    Vilhena, Karyme S S; Guilhon, Giselle Maria Skelding Pinheiro; Zoghbi, Maria das Graças B; Santos, Lourivaldo Silva; Souza Filho, Antonio Pedro Silva

    2014-01-01

    Chemical investigation of the rhizomes of Cyperus distans (Cyperaceae) led to the identification of α-ciperone, cyperotundone and scabequinone, besides other common constituents. Complete assignment of the (13)C NMR data of scabequinone is being published for the first time. The inhibitory effects of C. distans extracts and scabequinone on the seed germination and seedling growth of Mimosa pudica, Senna obtusifolia and Pueraria phaseoloides were evaluated. Seed germination inhibition bioassay revealed that S. obtusifolia (52-53%) was more sensitive to the hexane and the methanol extracts at 1% than M. pudica (0-10%). Scabequinone at 250 mg L⁻¹ displayed seed germination inhibitions more than 50% and radicle growth reduction of more than 35% of the test species S. obtusifolia and P. phaseoloides, while the hypocotyl growth of M. pudica was significantly affected (>50%) by the quinone at the same concentration. These results demonstrate that scabequinone contributes to the overall inhibitory activities of C. distans.

  15. Chemical investigation of Cyperus distans L. and inhibitory activity of scabequinone in seed germination and seedling growth bioassays.

    PubMed

    Vilhena, Karyme S S; Guilhon, Giselle Maria Skelding Pinheiro; Zoghbi, Maria das Graças B; Santos, Lourivaldo Silva; Souza Filho, Antonio Pedro Silva

    2014-01-01

    Chemical investigation of the rhizomes of Cyperus distans (Cyperaceae) led to the identification of α-ciperone, cyperotundone and scabequinone, besides other common constituents. Complete assignment of the (13)C NMR data of scabequinone is being published for the first time. The inhibitory effects of C. distans extracts and scabequinone on the seed germination and seedling growth of Mimosa pudica, Senna obtusifolia and Pueraria phaseoloides were evaluated. Seed germination inhibition bioassay revealed that S. obtusifolia (52-53%) was more sensitive to the hexane and the methanol extracts at 1% than M. pudica (0-10%). Scabequinone at 250 mg L⁻¹ displayed seed germination inhibitions more than 50% and radicle growth reduction of more than 35% of the test species S. obtusifolia and P. phaseoloides, while the hypocotyl growth of M. pudica was significantly affected (>50%) by the quinone at the same concentration. These results demonstrate that scabequinone contributes to the overall inhibitory activities of C. distans. PMID:24941231

  16. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    PubMed

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic.

  17. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    PubMed

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic. PMID:23978671

  18. Evaluation of phytotoxicity effect of olive mill wastewater treated by different technologies on seed germination of barley (Hordeum vulgare L.).

    PubMed

    Rusan, Munir J M; Albalasmeh, Ammar A; Zuraiqi, Said; Bashabsheh, Mohammad

    2015-06-01

    Olive-mill wastewater (OMW) is a by-product effluent of olive oil extraction process that is produced in large amount in the Mediterranean region. OMW is believed to induce phytotoxic effect on organisms including seed germination and plant growth. The objective of this study was to evaluate the impact of untreated and treated OMW with different techniques on seed germination of barley (Hordeum vulgare L.). The following treatments were investigated: (1) tap water (control); (2) OMW treated by aerobic biological technology in a Jacto Reactor (JR); (3) OMW treated by solar fenton oxidation (SFO); (4) OMW treated by microfiltration followed by nanofiltration (MF+NF); (5) OMW treated by microfiltration followed by reverse osmosis (MF+RO) process; (6) diluted OMW with tap water (25 % OMW); (7) diluted OMW with tap water (50 % OMW); (8) diluted OMW with tap water (75 % OMW); and (9) untreated OMW (100 % OMW). A germination test was conducted in an incubator at temperature of 23 (∘)C. In each petri dish, a filter paper was mounted and ten seeds of barley were placed on the filter paper. Five milliliter of water were added to each petri dish. The seed germination was determined by counting the number of germinated seeds to calculate the percentage of germination (G %). Germination rate index (GRI), seed vigor index (SVI), and phytotoxicity index (PI) were also calculated. Then, the dry weights and lengths of the shoots and the roots of the germinated seeds were measured. The results show that 100, 75, and 50 %OMW were very phytotoxic and completely prohibited seed germination. However, phytotoxicity decreased significantly following treatments of OMW with all techniques investigated and by the 25 % OMW dilution, as results of removing the phenols and other phytotoxic organic compounds from the OMW or by diluting it. This was evidenced by relative enhancement of the dry weights and lengths of shoot and root as well as the G %, GRI, SVG, and PI. It was concluded that if

  19. Evaluation of phytotoxicity effect of olive mill wastewater treated by different technologies on seed germination of barley (Hordeum vulgare L.).

    PubMed

    Rusan, Munir J M; Albalasmeh, Ammar A; Zuraiqi, Said; Bashabsheh, Mohammad

    2015-06-01

    Olive-mill wastewater (OMW) is a by-product effluent of olive oil extraction process that is produced in large amount in the Mediterranean region. OMW is believed to induce phytotoxic effect on organisms including seed germination and plant growth. The objective of this study was to evaluate the impact of untreated and treated OMW with different techniques on seed germination of barley (Hordeum vulgare L.). The following treatments were investigated: (1) tap water (control); (2) OMW treated by aerobic biological technology in a Jacto Reactor (JR); (3) OMW treated by solar fenton oxidation (SFO); (4) OMW treated by microfiltration followed by nanofiltration (MF+NF); (5) OMW treated by microfiltration followed by reverse osmosis (MF+RO) process; (6) diluted OMW with tap water (25 % OMW); (7) diluted OMW with tap water (50 % OMW); (8) diluted OMW with tap water (75 % OMW); and (9) untreated OMW (100 % OMW). A germination test was conducted in an incubator at temperature of 23 (∘)C. In each petri dish, a filter paper was mounted and ten seeds of barley were placed on the filter paper. Five milliliter of water were added to each petri dish. The seed germination was determined by counting the number of germinated seeds to calculate the percentage of germination (G %). Germination rate index (GRI), seed vigor index (SVI), and phytotoxicity index (PI) were also calculated. Then, the dry weights and lengths of the shoots and the roots of the germinated seeds were measured. The results show that 100, 75, and 50 %OMW were very phytotoxic and completely prohibited seed germination. However, phytotoxicity decreased significantly following treatments of OMW with all techniques investigated and by the 25 % OMW dilution, as results of removing the phenols and other phytotoxic organic compounds from the OMW or by diluting it. This was evidenced by relative enhancement of the dry weights and lengths of shoot and root as well as the G %, GRI, SVG, and PI. It was concluded that if

  20. Adjuvant and refined corn oil formulation effects on conidial germination, appressorial formation and virulence of the bioherbicide, Colletotrichum truncatum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several surfactants, plant extracts, and fatty acids were tested for stimulation of conidial germination and appressorial formation of Colletotrichum truncatum, a bioherbicide of the weed, hemp sesbania (Sesbania exaltata). The commercial surfactants (Tweens® 40, 60, 80, 85 and Myvatex® 60) at conc...