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Sample records for seed imbibition curve

  1. Imbibition and germination in the seeds of Heliotropium supinum L.

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    Ramesh C. Bhatia

    2014-01-01

    Full Text Available Imbibition in the seeds of Heliotropium supinum L. varies under different temperatures. The optimum temperatures for imbibition and germination are also different. For germination 39% imbibition is essential, and this capability is achieved by 12-week-old seeds. With duration of dry storage imbibition increases. The imbibition and germination percentages decline on re-dry storage of seeds after embeding in mud. A soil moisture of 44% is optimal for germination. A correlation exists between imbibition and germination.

  2. Imbibition of wheat seeds: Application of image analysis

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    Lev, Jakub; Blahovec, Jiří

    2017-10-01

    Image analysis is widely used for monitoring seeds during germination, and it is often the final phase of germination that is subjected to the greatest attention. However, the initial phase of germination (the so-called imbibition) also exhibits interesting behaviour. This work shows that image analysis has significant potential in the imbibition. Herein, a total of 120 seeds were analysed during germination tests, and information about seed size and shape was stored and analysed. It was found that the imbibition can be divided into two newly defined parts. The first one (`abrupt imbibition') consists mainly of the swelling of the seed embryo part and lasts approximately one hour. The second one, referred to as `main imbibition', consists mainly of spatial expansion caused by imbibition in the other parts of the seed. The results presented are supported by the development of seed cross area and shape parameters, and by direct observation.

  3. Solar-Terrestrial Effects on Bean Seed Imbibition

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    Minorsky, P. V.

    2012-12-01

    Forty years ago, a lively debate ensued amongst biologists concerning the nature of biological rhythms. The "endogenous" school argued that biological rhythms that occur in the absence of any obvious environmental oscillation arise endogenously from within the organism itself. The "exogenous" school on the other hand proposed that subtle and pervasive exogenous factors (e.g., geomagnetic variations or cosmic radiation) underlie most biological rhythms. Much of the debate between the endogenous vs. exogenous schools focused on circadian (circa-24 h) rhythms in particular. The demonstration that circadian rhythms continue in orbiting spacecraft was widely regarded as the final nail in the coffin of the "exogenous" school, and the entire school sank into obscurity. Regrettably, the demise of the "exogenous" school also caused some interesting findings concerning non-circadian rhythms to fall into oblivion as well. Three different research groups, for example, reported that bean (Phaseolus vulgaris) seeds display rhythms in imbibition that have ~7- or ~14-day periodicities. Consistent with the idea of an exogenous synchronizer, these rhythms often occurred synchronously in bean seed populations located 1500 km apart. The present experiment was initiated with the intention of examining whether these ~7 and ~14 d oscillations in imbibition corresponded to oscillations in solar-terrestrial parameters. Three replicates of ~25 g of bean seeds (Phaseolus vulgaris cv. Provider) were weighed daily and placed into beakers containing 200 ml of distilled water at 25° C. This temperature was maintained by nesting the beakers inside larger, temperature-jacketed beakers through which water from a temperature-regulated water bath was circulated. Four hours later the experiments were terminated: the bean seeds were blotted and weighed. Experiments were conducted almost every day between 3 and 7 AM UT from Jan 18, 2007 to Feb 26, 2008. A major difference between the present study and

  4. Ageing increases the sensitivity of neem (Azadirachta indica) seeds to imbibitional stress

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    Neya, O.; Golovina, E.A.; Nijsse, J.; Hoekstra, F.A.

    2004-01-01

    Imbibitional stress was imposed on neem (Azadirachta indica) seeds by letting them soak for 1 h in water at unfavourable, low temperatures before further incubation at 30degreesC. Sensitivity to low imbibition temperatures increased with a decrease in seed moisture content (MC). To investigate a

  5. Scaling of counter-current imbibition recovery curves using artificial neural networks

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    Jafari, Iman; Masihi, Mohsen; Nasiri Zarandi, Masoud

    2018-06-01

    Scaling imbibition curves are of great importance in the characterization and simulation of oil production from naturally fractured reservoirs. Different parameters such as matrix porosity and permeability, oil and water viscosities, matrix dimensions, and oil/water interfacial tensions have an effective on the imbibition process. Studies on the scaling imbibition curves along with the consideration of different assumptions have resulted in various scaling equations. In this work, using an artificial neural network (ANN) method, a novel technique is presented for scaling imbibition recovery curves, which can be used for scaling the experimental and field-scale imbibition cases. The imbibition recovery curves for training and testing the neural network were gathered through the simulation of different scenarios using a commercial reservoir simulator. In this ANN-based method, six parameters were assumed to have an effect on the imbibition process and were considered as the inputs for training the network. Using the ‘Bayesian regularization’ training algorithm, the network was trained and tested. Training and testing phases showed superior results in comparison with the other scaling methods. It is concluded that using the new technique is useful for scaling imbibition recovery curves, especially for complex cases, for which the common scaling methods are not designed.

  6. Roles of mucilage in Emilia fosbergii, a myxocarpic Asteraceae: Efficient seed imbibition and diaspore adhesion.

    Science.gov (United States)

    De-Paula, Orlando C; Marzinek, Juliana; Oliveira, Denise M T; Paiva, Élder A S

    2015-09-01

    Several angiosperm families have myxodiaspory, such as the Asteraceae in which cypselae are frequently wind-dispersed. The roles of mucilage in cypselae remain misunderstood, and the route of water uptake from substrate to embryo remains unknown. In this work, we analyze the fruits of Emilia fosbergii aiming to clarify how the water is absorbed and how the structure of the pericarp can be related to the processes of diaspore adhesion and seed imbibition. The anatomy and ultrastructure of the cypselae of Emilia fosbergii were analyzed with histochemical tests and light, scanning and transmission electron microscopy. We assessed the roles of mucilage in seed imbibition using apoplasmic tracing with Lucifer yellow and epifluorescence microscopy and in adhesion with a sand assay. We describe structural and ultrastructural aspects of the exocarpic cells, especially the mucilaginous twin hairs. Lucifer yellow was absorbed only by the twin hairs, the cells where water primarily enters the seed during seed imbibition. In the sand assay, the mucilage was adhesive. The twin hairs on the surface of the cypselae can play a dual role in the establishment of new plants of this species. First, these trichomes constitute the main passage for water intake, which is essential for seed imbibition and germination, and after imbibition, they release mucilage that can adhere the diaspore. Therefore, the presence of myxocarpy in Asteraceae could be important in anemochoric species to avoid secondary dispersal. © 2015 Botanical Society of America.

  7. Studies on the Vigour of Soybean Seeds : II. Varietal Differences in Seed Coat Quality and Swelling Components of Seed during Moisture Imbibition

    OpenAIRE

    Mugnisjah, Wahju Qamara; Shimano, Itaru; Matsumoto, Shigeo; 島野, 至; 松本, 重男

    1987-01-01

    Laboratory experiment was conducted to elucidate the physiological factor determining the association of seed size and seed coat quality with varietal differences in seed vigour, and to pursue an alternative on the mechanism of varietal differences in seed resistance to field weathering. Results of this study revealed that seed polymer change (seed volume change minus seed weight change during moisture imbibition) was the physiological factor determining the association of seed size and seed ...

  8. Control of seed dormancy in Nicotiana plumbaginifolia: post-imbibition abscisic acid synthesis imposes dormancy maintenance.

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    Grappin, P; Bouinot, D; Sotta, B; Miginiac, E; Jullien, M

    2000-01-01

    The physiological characteristics of seed dormancy in Nicotiana plumbaginifolia Viv. are described. The level of seed dormancy is defined by the delay in seed germination (i.e the time required prior to germination) under favourable environmental conditions. A wild-type line shows a clear primary dormancy, which is suppressed by afterripening, whereas an abscisic acid (ABA)-deficient mutant shows a non-dormant phenotype. We have investigated the role of ABA and gibberellic acid (GA(3)) in the control of dormancy maintenance or breakage during imbibition in suitable conditions. It was found that fluridone, a carotenoid biosynthesis inhibitor, is almost as efficient as GA(3) in breaking dormancy. Dry dormant seeds contained more ABA than dry afterripened seeds and, during early imbibition, there was an accumulation of ABA in dormant seeds, but not in afterripened seeds. In addition, fluridone and exogenous GA(3) inhibited the accumulation of ABA in imbibed dormant seeds. This reveals an important role for ABA synthesis in dormancy maintenance in imbibed seeds.

  9. Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature

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    Nascimento Warley Marcos

    2003-01-01

    Full Text Available Lettuce (Lactuca sativa L. seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB were incubated at temperatures ranging from 15degrees to 35degreesC at light and dark conditions. Other seeds were imbibed in dark at 20degrees; 25degrees; 30degrees; and 35degreesC for 8 and 16 hours and then transferred to 20 or 35degreesC, in dark. Seeds were also incubated at constant temperature of 20degrees and 35 degreesC, in the dark, as control. In another treatment, seeds were primed for 3 days at 15degreesC with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25degreesC. Seeds incubated at 20degreesC had 97% germination, whereas seeds incubated at 35degreesC did not germinate. Seeds imbibed at 20degreesC for 8 and 16 hours had germination. At 35degreesC, seeds imbibed initially at 20degreesC for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25degreesC for 16 hours, germinated satisfactory at 35degreesC. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20degreesC. Primed seeds had 100% germination at 35degreesC, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.

  10. Morpho-anatomy, imbibition, viability and germination of the seed of Anadenanthera colubrina var. cebil (Fabaceae).

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    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

  11. Metabolite profiling of the oilseed crop Ricinus communis during early seed imbibition reveals a specific metabolic signature in response to temperature

    NARCIS (Netherlands)

    Ribeiro de Jesus, P.R.; Willems, L.A.J.; Mudde, E.; Fernandez, L.G.; Castro, de R.D.; Ligterink, W.; Hilhorst, H.W.M.

    2015-01-01

    Seed imbibition is an important process in the plant life cycle and determines whether seed germination and plant growth will be successful or not. Ricinus communis is becoming an important crop for oil production, and therefore, studying the physiological and biochemical aspects of seed imbibition

  12. Improvements in scaling of counter-current imbibition recovery curves using a shape factor including permeability anisotropy

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    Abbasi, Jassem; Sarafrazi, Shiva; Riazi, Masoud; Ghaedi, Mojtaba

    2018-02-01

    Spontaneous imbibition is the main oil production mechanism in the water invaded zone of a naturally fractured reservoir (NFR). Different scaling equations have been presented in the literature for upscaling of core scale imbibition recovery curves to field scale matrix blocks. Various scale dependent parameters such as gravity effects and boundary influences are required to be considered in the upscaling process. Fluid flow from matrix blocks to the fracture system is highly dependent on the permeability value in the horizontal and vertical directions. The purpose of this study is to include permeability anisotropy in the available scaling equations to improve the prediction of imbibition assisted oil production in NFRs. In this paper, a commercial reservoir simulator was used to obtain imbibition recovery curves for different scenarios. Then, the effect of permeability anisotropy on imbibition recovery curves was investigated, and the weakness of the existing scaling equations for anisotropic rocks was demonstrated. Consequently, an analytical shape factor was introduced that can better scale all the curves related to anisotropic matrix blocks.

  13. Imbibition and percentage of germination of cape gooseberry (Physalis peruviana L. seeds under NaCl stress

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    Miranda Diego

    2010-04-01

    Full Text Available

    In Colombia cape gooseberry is often grown on salt affected soils. The present study evaluated the effect of increasing NaCl concentrations on imbibition and percentage of germination of ‘Colombia’ ecotype cape gooseberry seeds. Under controlled laboratory conditions (25/20°C day/night temperature, 80% relative humidity, and a 12 hour photoperiod, the seeds were subjected to 0, 30, 60, 90 and 120 mM NaCl concentrations (corresponding to respective electrical conductivity levels of 0.8, 3.0, 6.0, 9.0, and 12.2 dS m-1, during an evaluation period of 299 hours. A significantly lower imbibition level, expressed as 35% of the fresh weight accumulated by the control seeds, was observed in the 120 mM NaCl treatment. At the end of the experiment, respective germination percentages of 97.6% and 96.4% were recorded in the salt-free seeds and in those exposed to 30 mM NaCl. In contrast, only 62.5% of those seeds treated with 120 mM NaCl germinated. Root malformations such as lack of elongation were observed in the highest NaCl concentration treatment. Regarding its germination process, cape gooseberry can be classified as moderately tolerant to sodium. In effect, after 299 h of treatment, there was no statistical difference in imbibition level or percentage of germination between the 0, 30 and 60 mM NaCl treatments.

  14. FRUIT AND SEED BIOMETRY AND DETERMINATION OF THE WATER ABSORPTION CURVE OF SESBANIA VIRGATA (CAV. PERS.

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    S Acchile

    2017-10-01

    Full Text Available The species Sesbania virgata (Cav. Pers., Fabaceae popularly known as Sesbania or Feijão do Mato, presents potential in the use in areas of afforestation and reforestation forests riparian and degraded areas. The aim of this study was to characterize the biometric of fruits and seeds and determine the germination pattern of the sesbânia seeds. The biometry of the seeds and fruits were established through the characterization of 250 fruits and 500 seeds, which were distributed in frequency classes through position, dispersion and normality measurements. The weight of one thousand seeds (PMS was determined using eight sub samples of the 100 seeds. For to study of the water absorption curve of the seeds were used two replicates of 100 seeds, it weighed in 32 intervals. In this sense, the biometric fruits aspects of S. virgata presented average values for length, width, thickness, weight and number of seeds per fruit of 5.87 cm, 0.78 cm, 0.58 cm, 0.85 g and 5 units, respectively. In relation to the seeds, the average length, width, thickness and seed weight were 0.623 cm; 0.439 cm; 0.316 cm and 0.075 g, respectively. The water absorption of S. virgata seed imbibition presented triphasic pattern, resembling several species of the same family.

  15. Expression patterns of ABA and GA metabolism genes and hormone levels during rice seed development and imbibition: a comparison of dormant and non-dormant rice cultivars.

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    Liu, Yang; Fang, Jun; Xu, Fan; Chu, Jinfang; Yan, Cunyu; Schläppi, Michael R; Wang, Youping; Chu, Chengcai

    2014-06-20

    Seed dormancy is an important agronomic trait in cereals. Using deep dormant (N22), medium dormant (ZH11), and non-dormant (G46B) rice cultivars, we correlated seed dormancy phenotypes with abscisic acid (ABA) and gibberellin (GA) metabolism gene expression profiles and phytohormone levels during seed development and imbibition. A time course analysis of ABA and GA content during seed development showed that N22 had a high ABA level at early and middle seed developmental stages, while at late developmental stage it declined to the level of ZH11; however, its ABA/GA ratio maintained at a high level throughout seed development. By contrast, G46B had the lowest ABA content during seed development though at early developmental stage its ABA level was close to that of ZH11, and its ABA/GA ratio peaked at late developmental stage that was at the same level of ZH11. Compared with N22 and G46B, ZH11 had an even and medium ABA level during seed development and its ABA/GA ratio peaked at the middle developmental stage. Moreover, the seed development time-point having high ABA/GA ratio also had relatively high transcript levels for key genes in ABA and GA metabolism pathways across three cultivars. These indicated that the embryo-imposed dormancy has been induced before the late developmental stage and is determined by ABA/GA ratio. A similar analysis during seed imbibition showed that ABA was synthesized in different degrees for the three cultivars. In addition, water uptake assay for intact mature seeds suggested that water could permeate through husk barrier into seed embryo for all three cultivars; however, all three cultivars showed distinct colors by vanillin-staining indicative of the existence of flavans in their husks, which are dormancy inhibition compounds responsible for the husk-imposed dormancy. Copyright © 2014. Published by Elsevier Ltd.

  16. Embebição e germinação de sementes de camu-camu = Imbibition and germination of camu-camu seeds

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    Antonio Baldo Geraldo Martins

    2006-10-01

    Full Text Available Objetivando verificar o comportamento das sementes de camu-camu, quanto à germinação, em função da embebição, realizou-se o presente trabalho, utilizando-se sementes extraídas de frutos maduros, provenientes de plantas adultas. Os tratamentos consistiram em seis tempos de pré-embebição: 0 (testemunha, 4, 8, 12, 24 e 36 horas. Após cada período, as sementes foram colocadas em caixas tipo gerbox, tendo como substrato vermiculita textura fina, e mantidas em germinadores BOD à temperatura constante de 25ºC. Para cada tratamento foram realizadas 4 repetições com 25 sementes cada. Realizaram-se avaliações diárias do número de sementes germinadas, sendo os dados agrupados semanalmente e transformados em arc sen x / 100 para fins de análise estatística. As médias foram comparadas pelo teste de Tukey, a 5% de probabilidade. Pelos resultados obtidos, pode-se concluir que a germinação das sementes de camu-camu não é influenciada pela embebição, bem como pelo período deste tratamento.This research was carried out aiming to verify the behavior of camu-camu seeds in their germination, according to imbibition periods. The seeds were extracted from ripe fruits of old plants. The treatments consisted of six preimbibition periods: 0, 4, 8, 12, 24 and 36 hours. After each period, the seeds were placed in gerbox, having vermiculite as substrate. They were maintained in a temperature of 25oC, in a germination chamber (BOD type. For each treatment, 4 replications with 25 seeds in each one were accomplished. Daily evaluations of the number of germinated seeds were done. The data were grouped weekly and they were transformed in arc sen x / 100 . The means were compared by the Tukey test (5% probability. Results showed that the germination of camu-camu seeds is not influenced by the imbibition, as well as by the period of this treatment.

  17. Differentially expressed genes during the imbibition of dormant and after-ripened seeds - a reverse genetics approach

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    Yazdanpanah, Farzaneh; Hanson, Johannes; Hilhorst, Henk W.M.; Bentsink, Leónie

    2017-01-01

    Background: Seed dormancy, defined as the incapability of a viable seed to germinate under favourable conditions, is an important trait in nature and agriculture. Despite extensive research on dormancy and germination, many questions about the molecular mechanisms controlling these traits remain

  18. Molecular analysis of endo-β-mannanase genes upon seed imbibition suggest a cross-talk between radicle and micropylar endosperm during germination of Arabidopsis thaliana

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    Iglesias-Fernández, Raquel; del Carmen Rodríguez-Gacio, María; Barrero-Sicilia, Cristina; Carbonero, Pilar

    2011-01-01

    The endo-β-mannanase (MAN) family is represented in the Arabidopsis genome by eight members, all with canonical signal peptides and only half of them being expressed in germinating seeds. The transcripts of these genes were localized in the radicle and micropylar endosperm (ME) before radicle protrusion and this expression disappears as soon as the endosperm is broken by the emerging radicle tip. However, only three of these MAN genes, AtMAN5, AtMAN7 and especially AtMAN6 influence the germination time (t50) as assessed by the analysis of the corresponding knock-out lines. The data suggest a possible interaction between embryo and ME regarding the role of MAN during the Arabidopsis germination process. PMID:21301215

  19. Validity of accessible critical nitrogen dilution curves in perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Gislum, René; Boelt, Birte

    2009-01-01

    The objectives were to test if accessible critical nitrogen dilution curves (NDCs) in rapeseed, pea, alfalfa, tall fescue, wheat, annual ryegrass and linseed could be used in grass species for seed production and to develop a critical NDC especially in grass species for seed production. The criti......The objectives were to test if accessible critical nitrogen dilution curves (NDCs) in rapeseed, pea, alfalfa, tall fescue, wheat, annual ryegrass and linseed could be used in grass species for seed production and to develop a critical NDC especially in grass species for seed production...... the NDCs in tall fescue, alfalfa, pea and rapeseed. These findings should be used to continue the interesting and necessary work on developing a NDC in grass species for seed production....

  20. DNA fingerprinting validates seed dispersal curves from observational studies in the neotropical legume parkia.

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    Heymann, Eckhard W; Lüttmann, Kathrin; Michalczyk, Inga M; Saboya, Pedro Pablo Pinedo; Ziegenhagen, Birgit; Bialozyt, Ronald

    2012-01-01

    Determining the distances over which seeds are dispersed is a crucial component for examining spatial patterns of seed dispersal and their consequences for plant reproductive success and population structure. However, following the fate of individual seeds after removal from the source tree till deposition at a distant place is generally extremely difficult. Here we provide a comparison of observationally and genetically determined seed dispersal distances and dispersal curves in a Neotropical animal-plant system. In a field study on the dispersal of seeds of three Parkia (Fabaceae) species by two Neotropical primate species, Saguinus fuscicollis and Saguinus mystax, in Peruvian Amazonia, we observationally determined dispersal distances. These dispersal distances were then validated through DNA fingerprinting, by matching DNA from the maternally derived seed coat to DNA from potential source trees. We found that dispersal distances are strongly right-skewed, and that distributions obtained through observational and genetic methods and fitted distributions do not differ significantly from each other. Our study showed that seed dispersal distances can be reliably estimated through observational methods when a strict criterion for inclusion of seeds is observed. Furthermore, dispersal distances produced by the two primate species indicated that these primates fulfil one of the criteria for efficient seed dispersers. Finally, our study demonstrated that DNA extraction methods so far employed for temperate plant species can be successfully used for hard-seeded tropical plants.

  1. DNA Fingerprinting Validates Seed Dispersal Curves from Observational Studies in the Neotropical Legume Parkia

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    Heymann, Eckhard W.; Lüttmann, Kathrin; Michalczyk, Inga M.; Saboya, Pedro Pablo Pinedo; Ziegenhagen, Birgit; Bialozyt, Ronald

    2012-01-01

    Background Determining the distances over which seeds are dispersed is a crucial component for examining spatial patterns of seed dispersal and their consequences for plant reproductive success and population structure. However, following the fate of individual seeds after removal from the source tree till deposition at a distant place is generally extremely difficult. Here we provide a comparison of observationally and genetically determined seed dispersal distances and dispersal curves in a Neotropical animal-plant system. Methodology/Principal Findings In a field study on the dispersal of seeds of three Parkia (Fabaceae) species by two Neotropical primate species, Saguinus fuscicollis and Saguinus mystax, in Peruvian Amazonia, we observationally determined dispersal distances. These dispersal distances were then validated through DNA fingerprinting, by matching DNA from the maternally derived seed coat to DNA from potential source trees. We found that dispersal distances are strongly right-skewed, and that distributions obtained through observational and genetic methods and fitted distributions do not differ significantly from each other. Conclusions/Significance Our study showed that seed dispersal distances can be reliably estimated through observational methods when a strict criterion for inclusion of seeds is observed. Furthermore, dispersal distances produced by the two primate species indicated that these primates fulfil one of the criteria for efficient seed dispersers. Finally, our study demonstrated that DNA extraction methods so far employed for temperate plant species can be successfully used for hard-seeded tropical plants. PMID:22514748

  2. Isodose curves recorded in radiochromic film of an iodine seed array

    International Nuclear Information System (INIS)

    Mourao, Arnaldo Prata; Tomaz, Lucas Crusoe; Grynberg, Suely Epzstein

    2015-01-01

    Brachytherapy seeds are frequently used in cancer treatment. Iodine seeds are ranked among the top choices when it comes to the treatment of prostate cancer. Iodine-125 emits X and gamma photons with an average energy of 28 keV and a half-life of 59.4 days. A set of four iodine-125 seeds, model 6711 produced by Amersham Health, were used in this work. The dosimetric characteristics for a seed were obtained taking into account the recommendations of TG-43 protocol, developed by the AAPM (American Association of Physicists in Medicine). To realize the experiment three plates of Standard Grade Solid Water, model 457 ® Gammex were used. One solid water plate was machined for accommodate the seed set. The set of seeds was placed in a symmetrical configuration trying to simulate an arrangement which may occur in vivo during treatment. A radiochromic film sheet was placed on the plate machined after the seed charge. The machined plate charged and with the film sheet was placed between two others solid water plate to recorder the radiation dose. The machined plate was placed between the other two plates for better reliability in measurements. The radio chromic film was irradiated by an equivalent X-ray beam using the reference radiation RQR 3 IEC (International Electrotechnical Commission) with different doses (0.5 to 1.0 Gy) to obtain the calibration curve in the dose region measured. After validation of the methodology, the study of the interaction between the radiation fields of the set of seeds became possible and the survey of isodose curves of these setting was conducted. (author)

  3. Temperatura óptima de germinación y patrones de imbibición de las semillas de Albizia lebbeck, Gliricidia sepium y Bauhinia purpurea Optimum germination temperature and imbibition patterns of the seeds from Albizia lebbeck, Gliricidia sepium and Bauhinia purpurea

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    J Reino

    2008-09-01

    substratum (constant 25ºC and three alternate ones: 25/30ºC, 25/35ºC and 25/40ºC. Before seeding the seeds of A. lebbeck were scarified (water at 80ºC/2'. For the imbibition pattern the seeds were put on filter paper moist with purified water according to the optimum germination temperature, under white fluorescent light and at different imbibition times. In the fresh seeds of all the species the highest percentages of final germination were obtained at alternate temperature of 25/35ºC and in the aged ones at 25/30ºC. With regards to the imbibition pattern they all followed a three-phase pattern of water absorption. The fresh and aged seeds of G. sepium showed a very similar imbibition pattern, however the fresh seeds of the other species presented higher hydration rate than the aged ones and consequently they reached faster the start of phase III of the imbibition pattern (i.e. visible germination. The range of optimum temperature for the germination of aged seeds was concluded to be 25/30 ºC and for the fresh ones it was 25/35 ºC and both showed a three-phase pattern of water absorption when the seeding was carried out at optimum germination temperature.

  4. ELECTRICAL CONDUCTIVITY OF SOYBEAN SEED CULTIVARS AND ADJUSTED MODELS OF LEAKAGE CURVES ALONG THE TIME

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    ADRIANA RITA SALINAS

    2010-01-01

    Full Text Available The objective of this work was to study the behavior of ten soybean [Glycine max (L. Merr.] cultivars using the electrical conductivity (EC test by the comparison of curves of the accumulative electrolyte leakage along the time and to establish the statistical model that allow the best adjust of the curves. Ten soybean cultivars were used and they were mechanically harvested in 2004 in the EEA Oliveros, Santa Fe, Argentina. Measurements of EC were made for 100 individual seeds of each cultivar during 20 hours of immersion at intervals of 1 hour using an equipment that permit an individual seed analysis (Seed Automatic Analyzer SAD 9000S. There were proposed two statistical models to study the EC along the time of the 10 cultivars studied using SAS Statistics Program, to select the model that better allow us to understand the EC behavior along the time. Model 1 allowed to make comparisons of EC along the time between cultivars and to study the influence of the production environment on the physiological quality of soybean seeds. The time to reach the stabilization of the EC must not be lower than 19 hours for the different cultivars.

  5. Water absorption curve among two size physic nut (Jatropha curcas L. seeds. = Curva de absorção de água em sementes de Jatropha curcas L. com dois tamanhos.

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    Oscar José Smiderle

    2013-08-01

    Full Text Available Knowledge of water absorption patterns among seeds is important as it allows us to know the appropriate conditions for the rapid seedling emergence. The present study characterized water absorption curve among physic nut (Jatropha curcas L seeds. Seeds were classified as small and large according to the mass of a thousand seeds placed in gerbox, between sheets of germitest paper moistened with destilled water 2.5 times their weight and kept in a germination chamber maintained at 25°C. The experimental design was completely randomized in a 2 x 17 factorial scheme, namely 2 seed sizes (large and small and 17 imbibitions periods (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 16, 24, 32, 48, 72, 96, 120 and 144 hours with four replicates of 10 seeds per plot. Small seeds of physic nut weighed 715.4 g as a thousand seed mass while large seeds weighed 800 grams. Seeds of physic nutexhibit a triphasic pattern of water absorption. Small and large physic nut seeds exhibit the three physiological phases similarly,where phase II begins next to 32 hours of imbibition and extends up to 116 hours, when phase III starts. = O conhecimento do padrão de absorção de água em sementes é importante na medida em que sepermite avaliar as condições adequadas para a rápida emergência das plântulas. Objetivou-se com o presente trabalho caracterizar a curva de absorção de água em sementes de pinhão manso (Jatropha curcas L.. Sementes classificadas por meio da massa de mil sementes em pequenas e grandes foram dispostas entre folhas de papel germitest umedecido 2,5 vezes seu peso, com água destilada, no interior de gerbox, mantidos em câmara de germinação a 25ºC. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2 x 17, sendo 2 tamanhos de sementes (grandes e pequenas, com 17 períodos de embebição (0; 0,5; 1; 2; 3; 4; 6; 8; 10; 16; 24; 32; 48; 72; 96; 120 e 144 horas e quatro repetições de 10 sementes por parcela. As sementes pequenas

  6. Curva de absorção de água em sementes de atemóia (Annona cherimola Mill. x Annona squamosa L. cv. Gefner Water absorption curve in seeds of atemoya (Annona cherimola Mill. x Annona squamosa L. cv. Gefner

    Directory of Open Access Journals (Sweden)

    Gisela Ferreira

    2006-04-01

    Full Text Available O presente trabalho teve o objetivo de caracterizar a curva de absorção de água em sementes de atemóia (Annona cherimola Mill x Annona squamosa L. cv. Gefner, submetidas a três métodos de embebição: sementes submersas em água destilada (MSSA, sementes entre papel de filtro embebido em água destilada acondicionada em caixa tipo gerbox (MPEA e teste-padrão (MTP, com sementes mantidas em rolo de papel de filtro umedecido em água destilada. O delineamento experimental foi o inteiramente casualizado, com 6 tratamentos e 4 repetições de 25 sementes por parcela, constituídos por três métodos de embebição, empregando-se sementes vivas e mortas. O tempo de embebição entre 27; 34 e 47 horas, nos métodos MTP, MPEA e MSSA, representam indicativo para tratamento de sementes, podendo funcionar como tempo mínimo necessário para embebição em solução com reguladores vegetais. Conclui-se que os métodos que caracterizaram as três fases de absorção de água em sementes de atemóia foram o MTP e MPEA com mudança entre as fases I e II após 27 e 34 horas, respectivamente, atingindo a fase III com 234 horas, o que permite determinar o tempo de imersão para tratamentos pré-germinativos.The present study aimed to characterize the water absorption curve in atemoya seeds (Annona cherimola Mill x Annona squamosa L. cv. Gefner, submitted to three imbibitions methods: seeds submerged in distilled water (MSSA, seed placed betwen paper filter imbibed with distilled water inside a gerbox box (MPEA and standard test, with seeds kept in roll of filter paper moistened with water (MTP. The experimental delineation was entirely randomized, with 6 treatments and 4 repetitions of 25 seeds per parcel. The treatments were submitted to three imbibitions methods, with live and deth seeds. The imbibition time among 27, 34 and 47 hours, in the MTP, MPEA and MSSA methods represented an indicative for seeds treatment, which could possibly function as a

  7. GERMINATOR: a software package for high-throughput scoring and curve fitting of Arabidopsis seed germination.

    Science.gov (United States)

    Joosen, Ronny V L; Kodde, Jan; Willems, Leo A J; Ligterink, Wilco; van der Plas, Linus H W; Hilhorst, Henk W M

    2010-04-01

    Over the past few decades seed physiology research has contributed to many important scientific discoveries and has provided valuable tools for the production of high quality seeds. An important instrument for this type of research is the accurate quantification of germination; however gathering cumulative germination data is a very laborious task that is often prohibitive to the execution of large experiments. In this paper we present the germinator package: a simple, highly cost-efficient and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The germinator package contains three modules: (i) design of experimental setup with various options to replicate and randomize samples; (ii) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (iii) curve fitting of cumulative germination data and the extraction, recap and visualization of the various germination parameters. The curve-fitting module enables analysis of general cumulative germination data and can be used for all plant species. We show that the automatic scoring system works for Arabidopsis thaliana and Brassica spp. seeds, but is likely to be applicable to other species, as well. In this paper we show the accuracy, reproducibility and flexibility of the germinator package. We have successfully applied it to evaluate natural variation for salt tolerance in a large population of recombinant inbred lines and were able to identify several quantitative trait loci for salt tolerance. Germinator is a low-cost package that allows the monitoring of several thousands of germination tests, several times a day by a single person.

  8. Effect of lead on imbibition, germination, and growth of Phaseolus vulgaris L. and Zea mays L.

    Directory of Open Access Journals (Sweden)

    Gustavo Isaza Guzmán Isaza Guzmán

    2013-07-01

    Full Text Available Lead is highly reactive and it can be consequently toxic to living cells to both plants and humans. This heavy metal is a source of contamination to the environment and it disrupts natural cycles. The present study was aimed to evaluate the effect of lead on the imbibition process, germination and growth in the bean (Phaseolus vulgaris L. and maize (Zea mays L.. It was developed a system consisting of receptacles to expose flooded plants at different concentrations of the metal. Results showed that at concentrations of 5 g l-1 lead imbibition process was affected, but was more evident in bean. Germination percentage was not affected in maize seeds, while viability was affected in bean seeds. We observed statistically that there is an effect on organ growth of root, stem and leaf in both species in the presence of solution whose effect is most noticeable in bean plants. Key words: heavy metals,phytoremediation, stress, toxic substances

  9. Pepper seed germination assessed by combined X-radiography and computer-aided imaging analysis

    International Nuclear Information System (INIS)

    Dell'Aquila, A.

    2007-01-01

    A lot of pepper seeds having 87% germination were subjected to X-ray inspection using a non lethal dose of radiation. Seeds with less than 2.7% (on the basis of total seed area) of free space area, i.e. the spaces between embryo and endosperm, were classified as highly viable seeds (97-100% germination) with the lowest level of abnormal seedlings. Seeds X-ray classified as good were subjected to a computerised image analysis to study seed imbibition and radicle elongation. The patterns of seed area increase, chosen as the most accurate indicator of seed swelling, resembled the triphasic curve of water uptake. The first phase was completed at 9 h followed by a second phase that varied widely in time until completion of germination between 52 and 96 h. The proportion of seeds with radicle protrusion between 52-56 h and 64-72 h assessed with the image analysis was significantly higher than that recorded using a conventional germination test. In addition, the rate of increase of seed area during the third phase of imbibition, mostly due to protrusion of the radicle tip and its growth, was highly correlated with the corresponding radicle elongation rate

  10. Biphasic Fluence-Response Curves for Phytochrome-Mediated Kalanchoë Seed Germination 1

    Science.gov (United States)

    Rethy, Roger; Dedonder, Andrée; De Petter, Edwin; Van Wiemeersch, Luc; Fredericq, Henri; De Greef, Jan; Steyaert, Herman; Stevens, Hilde

    1987-01-01

    The fluence-response curves for the effect of two red pulses separated by 24 hours on the germination of Kalanchoe blossfeldiana Poelln. cv Vesuv seeds, incubated on gibberellic acid (GA3) are biphasic for suboptimal concentrations. The response in the low fluence range corresponds with a classical red/far-red reversible phytochrome mediated reaction. GA3 induces an additional response in the very low fluence range, which is also phytochrome mediated. The sensitivity to phytochrome-far-red absorbing form (Pfr), however, is increased about 20,000-fold, so that even far-red fluences become saturating. Both in the very low and low fluence response range, the maximal responses induced by saturating fluences are modulated by the GA3 concentration. GA3 having no direct influence on the phytochrome phototransformations, alters the Pfr requirement and determines the responding seed population fraction in the very low and low fluence range. The effet of GA3 appears to be on the transduction chain of the phytochrome signal. PMID:16665187

  11. Development of computational models for the simulation of isodose curves on dosimetry films generated by iodine-125 brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Adriano M.; Meira-Belo, Luiz C.; Reis, Sergio C.; Grynberg, Suely E., E-mail: amsantos@cdtn.b [Center for Development of Nuclear Technology (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The interstitial brachytherapy is one modality of radiotherapy in which radioactive sources are placed directly in the region to be treated or close to it. The seeds that are used in the treatment of prostate cancer are generally cylindrical radioactive sources, consisting of a ceramic or metal matrix, which acts as the carrier of the radionuclide and as the X-ray marker, encapsulated in a sealed titanium tube. This study aimed to develop a computational model to reproduce the film-seed geometry, in order to obtain the spatial regions of the isodose curves produced by the seed when it is put over the film surface. The seed modeled in this work was the OncoSeed 6711, a sealed source of iodine-125, which its isodose curves were obtained experimentally in previous work with the use of dosimetric films. For the films modeling, compositions and densities of the two types of dosimetric films were used: Agfa Personal Monitoring photographic film 2/10, manufactured by Agfa-Geavaert; and the model EBT radiochromic film, by International Specialty Products. The film-seed models were coupled to the Monte Carlo code MCNP5. The results obtained by simulations showed to be in good agreement with experimental results performed in a previous work. This indicates that the computational model can be used in future studies for other seeds models. (author)

  12. Development of computational models for the simulation of isodose curves on dosimetry films generated by iodine-125 brachytherapy seeds

    International Nuclear Information System (INIS)

    Santos, Adriano M.; Meira-Belo, Luiz C.; Reis, Sergio C.; Grynberg, Suely E.

    2011-01-01

    The interstitial brachytherapy is one modality of radiotherapy in which radioactive sources are placed directly in the region to be treated or close to it. The seeds that are used in the treatment of prostate cancer are generally cylindrical radioactive sources, consisting of a ceramic or metal matrix, which acts as the carrier of the radionuclide and as the X-ray marker, encapsulated in a sealed titanium tube. This study aimed to develop a computational model to reproduce the film-seed geometry, in order to obtain the spatial regions of the isodose curves produced by the seed when it is put over the film surface. The seed modeled in this work was the OncoSeed 6711, a sealed source of iodine-125, which its isodose curves were obtained experimentally in previous work with the use of dosimetric films. For the films modeling, compositions and densities of the two types of dosimetric films were used: Agfa Personal Monitoring photographic film 2/10, manufactured by Agfa-Geavaert; and the model EBT radiochromic film, by International Specialty Products. The film-seed models were coupled to the Monte Carlo code MCNP5. The results obtained by simulations showed to be in good agreement with experimental results performed in a previous work. This indicates that the computational model can be used in future studies for other seeds models. (author)

  13. Bypassing the learning curve in permanent seed implants using state-of-the-art technology

    International Nuclear Information System (INIS)

    Beaulieu, Luc; Evans, Dee-Ann Radford; Aubin, Sylviane; Angyalfi, Steven; Husain, Siraj; Kay, Ian; Martin, Andre-Guy; Varfalvy, Nicolas; Vigneault, Eric; Dunscombe, Peter

    2007-01-01

    Purpose: The aim of this study was to demonstrate, based on clinical postplan dose distributions, that technology can be used efficiently to eliminate the learning curve associated with permanent seed implant planning and delivery. Methods and Materials: Dose distributions evaluated 30 days after the implant of the initial 22 consecutive patients treated with permanent seed implants at two institutions were studied. Institution 1 (I1) consisted of a new team, whereas institution 2 (I2) had performed more than 740 preplanned implantations over a 9-year period before the study. Both teams had adopted similar integrated systems based on three-dimensional (3D) transrectal ultrasonography, intraoperative dosimetry, and an automated seed delivery and needle retraction system (FIRST, Nucletron). Procedure time and dose volume histogram parameters such as D90, V100, V150, V200, and others were collected in the operating room and at 30 days postplan. Results: The average target coverage from the intraoperative plan (V100) was 99.4% for I1 and 99.9% for I2. D90, V150, and V200 were 191.4 Gy (196.3 Gy), 75.3% (73.0%), and 37.5% (34.1%) for I1 (I2) respectively. None of these parameters shows a significant difference between institutions. The postplan D90 was 151.2 Gy for I1 and 167.3 Gy for I2, well above the 140 Gy from the Stock et al. analysis, taking into account differences at planning, results in a p value of 0.0676. The procedure time required on average 174.4 min for I1 and 89 min for I2. The time was found to decrease with the increasing number of patients. Conclusion: State-of-the-art technology enables a new brachytherapy team to obtain excellent postplan dose distributions, similar to those achieved by an experienced team with proven long-term clinical results. The cost for bypassing the usual dosimetry learning curve is time, with increasing team experience resulting in shorter treatment times

  14. Imbibition Triggered by Capillary Condensation in Nanopores.

    Science.gov (United States)

    Vincent, Olivier; Marguet, Bastien; Stroock, Abraham D

    2017-02-21

    We study the spatiotemporal dynamics of water uptake by capillary condensation from unsaturated vapor in mesoporous silicon layers (pore radius r p ≃ 2 nm), taking advantage of the local changes in optical reflectance as a function of water saturation. Our experiments elucidate two qualitatively different regimes as a function of the imposed external vapor pressure: at low vapor pressures, equilibration occurs via a diffusion-like process; at high vapor pressures, an imbibition-like wetting front results in fast equilibration toward a fully saturated sample. We show that the imbibition dynamics can be described by a modified Lucas-Washburn equation that takes into account the liquid stresses implied by Kelvin equation.

  15. Imbibition of ``Open Capillary'': Fundamentals and Applications

    Science.gov (United States)

    Tani, Marie; Kawano, Ryuji; Kamiya, Koki; Okumura, Ko

    2015-11-01

    Control or transportation of small amount of liquid is one of the most important issues in various contexts including medical sciences or pharmaceutical industries to fuel delivery. We studied imbibition of ``open capillary'' both experimentally and theoretically, and found simple scaling laws for both statics and dynamics of the imbibition, similarly as that of imbibition of capillary tubes. Furthermore, we revealed the existence of ``precursor film,'' which developed ahead of the imbibing front, and the dynamics of it is described well by another scaling law for capillary rise in a corner. Then, to show capabilities of open capillaries, we demonstrated two experiments by fabricating micro mixing devices to achieve (1) simultaneous multi-color change of the Bromothymol blue (BTB) solution and (2) expression of the green florescent protein (GFP). This research was partly supported by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan). M. T. is supported by the Japan Society for the Promotion of Science Research Fellowships for Young Scientists.

  16. Seed anatomy, moisture content and scarification influence on ...

    African Journals Online (AJOL)

    Low and erratic germination in wild banana seed is caused by dormancy due to physical, anatomical or physiological reasons. Imbibition activates germination process and the rate of water uptake during imbibition is influenced by seed molecular composition and internal and external morphological structures. The present ...

  17. Imbibition, germination and lipid mobilization response by sunflower subjected to salt stress

    International Nuclear Information System (INIS)

    Achakzai, A.K.K.

    2014-01-01

    Salinity is one of the most important abiotic stresses in arid and semi-arid regions that substantially reduce the germination, growth and average yield of major crops. The study was mainly aimed to select the most salt tolerant cultivar of sunflower. Therefore, a pot culture experiment was conducted to study the effects of four different salinity levels having electrical conductivity viz., 1.19, 9.54, 16.48 and 22.38 mS/cm on the imbibition (water uptake), germination and lipid mobilization of seedlings of 4 varieties of sunflower (Helianthus annuus L.) i.e., DO-728, DO-730, Hysun-33 and Suncross-843. Salinity levels were prepared by dissolving calculated amount of NaCl, Na/sub 2/SO/sub 4/, CaCl/sub 2/ and MgCl/sub 2/ (4:10:5:1) in half strength Hoagland culture solution. Imbibition was studied using plastic glasses at an interval of 12 and 24 hours. While germination studies were separately carried out in plastic pots and noted after every 12 hours till 20 days. Whereas, lipid contents of the salt stress germinating seeds were determined at three time intervals viz., 48, 96 and 144 hours of germination. Results showed that there was a linear decrease in imbibition, germination and lipid mobilization as the level of salinity progressively intensifies. Maximum significant reduction in imbibition (12.88%), germination (31.03%) and lipid mobilization (38.62%) is recorded in highest dose of applied salts (22.38 mS/cm). Results further exhibited that maximum significant reduction in imbibition (17.95%) and germination (43.05%) is recorded for variety Suncross-843. While minimum for the same attributes is recorded for variety DO-728. Therefore, in term of imbibitions and germination, DO-728 could be ranked as salt tolerant. Similarly maximum reduction (14.85%) in mobilized lipids is noted for DO-728 and minimum (40.89%) for DO-730. Therefore, in term of lipid mobilization, variety DO-730 could be ranked as salt tolerant and DO-728 as salt sensitive. While remaining 2

  18. Site Index Curves for Direct-Seeded Loblolly and Longleaf Pines in Louisiana

    Science.gov (United States)

    Quang V. Cao; V. Clark Baldwin; Richard E. Lohrey

    1995-01-01

    Site index equations were developed for direct-seeded loblollypine (Pinus taeda L.) and longleaf pine (Pinus palustris Mill.) based on data from 148 and 75 permanent plots, respectively. These plots varied from 0.053 to 0.119 ac in size, and were established in broadcast, row, and spot seeded stands throughout Louisiana. The Bailey and Clutter (1974) model was...

  19. Microgravity Investigation of Capillary Driven Imbibition

    Science.gov (United States)

    Dushin, V. R.; Nikitin, V. F.; Smirnov, N. N.; Skryleva, E. I.; Tyurenkova, V. V.

    2018-05-01

    The goal of the present paper is to investigate the capillary driven filtration in porous media under microgravity conditions. New mathematical model that allows taking into account the blurring of the front due to the instability of the displacement that is developing at the front is proposed. The constants in the mathematical model were selected on the basis of the experimental data on imbibition into unsaturated porous media under microgravity conditions. The flow under the action of a combination of capillary forces and a constant pressure drop or a constant flux is considered. The effect of capillary forces and the type of wettability of the medium on the displacement process is studied. A criterion in which case the capillary effects are insignificant and can be neglected is established.

  20. Effects of different depth of grain colour on antioxidant capacity during water imbibition in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Shin, Oon Ha; Kim, Dae Yeon; Seo, Yong Weon

    2017-07-01

    The importance of the effect of phytochemical accumulation in wheat grain on grain physiology has been recognised. In this study, we tracked phytochemical concentration in the seed coat of purple wheat during the water-imbibition phase and also hypothesised that the speed of germination was only relevant to its initial phytochemical concentration. The results indicate that the speed of germination was significantly reduced in the darker grain groups within the purple wheat. Total phenol content was slightly increased in all groups compared to their initial state, but the levels of other phytochemicals varied among groups. It is revealed that anthocyanin was significantly degraded during the water imbibition stage. Also, the activities of peroxidase, ascorbate peroxidase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase in each grain colour group did not correlated with germination speed. Overall antioxidant activity was reduced as imbibition progressed in each group. Generally, darker grain groups showed higher total antioxidant activities than did lighter grain groups. These findings suggested that the reduced activity of reactive oxygen species, as controlled by internal antioxidant enzymes and phytochemicals, related with germination speed during the water imbibition stage in grains with greater depth of purple colouring. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. Seed research for improved technologies

    OpenAIRE

    Bino,R.J.; Jalink,H.; Oluoch,M.O.; Groot,S.P.C.

    1998-01-01

    The production of high-quality seed is the basis for a durable a profitable agriculture. After production, seed is processed, conditioned, stored, shipped and germinated. For quality assurance, seed quality has to be controlled at all steps of the production chain. Seed functioning is accompanied by programmed transitions from cell proliferation to quiescence upon maturation and from quiescence to reinitiation of cellular metabolism upon imbibition. Despite the obvious importance of these con...

  2. Measuring and modeling water imbibition into tuff

    International Nuclear Information System (INIS)

    Peters, R.R.; Klavetter, E.A.; George, J.T.; Gauthier, J.H.

    1986-01-01

    Yucca Mountain (Nevada) is being investigated as a potential site for a high-level-radioactive-waste repository. The site combines a partially saturated hydrologic system and a stratigraphy of fractured, welded and nonwelded tuffs. The long time scale for site hydrologic phenomena makes their direct measurement prohibitive. Also, modeling is difficult because the tuffs exhibit widely varying, and often highly nonlinear hydrologic properties. To increase a basic understanding of both the hydrologic properties of tuffs and the modeling of flow in partially saturated regimes, the following tasks were performed, and the results are reported: (1) Laboratory Experiment: Water imbibition into a cylinder of tuff (taken from Yucca Mountain drill core) was measured by immersing one end of a dry sample in water and noting its weight at various times. The flow of water was approximately one-dimensional, filling the sample from bottom to top. (2) Computer Simulation: The experiment was modeled using TOSPAC (a one-dimensional, finite-difference computer program for simulating water flow in partially saturated, fractured, layered media) with data currently considered for use in site-scale modeling of a repository in Yucca Mountain. The measurements and the results of the modeling are compared. Conclusions are drawn with respect to the accuracy of modeling transient flow in a partially saturated, porous medium using a one-dimensional model and currently available hydrologic-property data

  3. Proteolytic and Trypsin Inhibitor Activity in Germinating Jojoba Seeds (Simmondsia chinensis) 1

    Science.gov (United States)

    Samac, Deborah; Storey, Richard

    1981-01-01

    Changes in proteolytic activity (aminopeptidase, carboxypeptidase, endopeptidase) were followed during germination (imbibition through seedling development) in extracts from cotyledons of jojoba seeds (Simmondsia chinensis). After imbibition, the cotyledons contained high levels of sulfhydryl aminopeptidase activity (APA) but low levels of serine carboxypeptidase activity (CPA). CPA increased with germination through the apparent loss of a CPA inhibitor substance in the seed. Curves showing changes in endopeptidase activity (EPA) assayed at pH 4, 5, 6, 7, and 8 during germination were distinctly different. EPA at pH 4, 5, 6, and 7 showed characteristics of sulfhydryl enzymes while activity at pH 8 was probably due to a serine type enzyme. EPA at pH 6 was inhibited early in germination by one or more substances in the seed. Activities at pH 5 and later at pH 6 were the highest of all EPA throughout germination and increases in these activities were associated with a rapid loss of protein from the cotyledons of the developing seedling. Jojoba cotyledonary extracts were found to inhibit the enzymic activity of trypsin, chymotrypsin, and pepsin but not the protease from Aspergillus saotoi. The heat-labile trypsin inhibitor substance(s) was found in commercially processed jojoba seed meal and the albumin fraction of seed proteins. Trypsin inhibitor activity decreased with germination. PMID:16662104

  4. Proteolytic and Trypsin Inhibitor Activity in Germinating Jojoba Seeds (Simmondsia chinensis).

    Science.gov (United States)

    Samac, D; Storey, R

    1981-12-01

    Changes in proteolytic activity (aminopeptidase, carboxypeptidase, endopeptidase) were followed during germination (imbibition through seedling development) in extracts from cotyledons of jojoba seeds (Simmondsia chinensis). After imbibition, the cotyledons contained high levels of sulfhydryl aminopeptidase activity (APA) but low levels of serine carboxypeptidase activity (CPA). CPA increased with germination through the apparent loss of a CPA inhibitor substance in the seed. Curves showing changes in endopeptidase activity (EPA) assayed at pH 4, 5, 6, 7, and 8 during germination were distinctly different. EPA at pH 4, 5, 6, and 7 showed characteristics of sulfhydryl enzymes while activity at pH 8 was probably due to a serine type enzyme. EPA at pH 6 was inhibited early in germination by one or more substances in the seed. Activities at pH 5 and later at pH 6 were the highest of all EPA throughout germination and increases in these activities were associated with a rapid loss of protein from the cotyledons of the developing seedling.Jojoba cotyledonary extracts were found to inhibit the enzymic activity of trypsin, chymotrypsin, and pepsin but not the protease from Aspergillus saotoi. The heat-labile trypsin inhibitor substance(s) was found in commercially processed jojoba seed meal and the albumin fraction of seed proteins. Trypsin inhibitor activity decreased with germination.

  5. Is seed conditioning essential for Orobanche germination?

    Science.gov (United States)

    Plakhine, Dina; Ziadna, Hammam; Joel, Daniel M

    2009-05-01

    Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity. Non-conditioned seeds of both Orobanche cumana Wallr. and O. aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] were able to germinate in response to chemical stimulation by GR24 even without prior conditioning. Stimulated seeds reached maximal germination rates about 2 weeks after the onset of imbibition, no matter whether the seeds had or had not been conditioned before stimulation. Whereas the lag time between stimulation and germination response of non-conditioned seeds was longer than for conditioned seeds, the total time between imbibition and germination was shorter for the non-conditioned seeds. Unlike the above two species, O. crenata Forsk. was found to require conditioning prior to stimulation. Seeds of O. cumana and O. aegyptiaca are already receptive before conditioning. Thus, conditioning is not involved in stimulant receptivity. A hypothesis is put forward, suggesting that conditioning includes (a) a parasite-specific early phase that allows the imbibed seeds to overcome the stress caused by failing to receive an immediate germination stimulus, and (b) a non-specific later phase that is identical to the pregermination phase between seed imbibition and actual germination that is typical for all higher plants.

  6. Biphasic fluence-response curves for phytochrome-mediated kalanchoë seed germination : sensitization by gibberellic Acid.

    Science.gov (United States)

    Rethy, R; Dedonder, A; De Petter, E; Van Wiemeersch, L; Fredericq, H; De Greef, J; Steyaert, H; Stevens, H

    1987-01-01

    The fluence-response curves for the effect of two red pulses separated by 24 hours on the germination of Kalanchoe blossfeldiana Poelln. cv Vesuv seeds, incubated on gibberellic acid (GA(3)) are biphasic for suboptimal concentrations. The response in the low fluence range corresponds with a classical red/far-red reversible phytochrome mediated reaction. GA(3) induces an additional response in the very low fluence range, which is also phytochrome mediated. The sensitivity to phytochrome-far-red absorbing form (Pfr), however, is increased about 20,000-fold, so that even far-red fluences become saturating. Both in the very low and low fluence response range, the maximal responses induced by saturating fluences are modulated by the GA(3) concentration. GA(3) having no direct influence on the phytochrome phototransformations, alters the Pfr requirement and determines the responding seed population fraction in the very low and low fluence range. The effet of GA(3) appears to be on the transduction chain of the phytochrome signal.

  7. Kinetics of solute leachate from imbibing Caesalpinia echinata Lam. (Brazilwood seeds

    Directory of Open Access Journals (Sweden)

    Nestor Martini Neto

    2014-02-01

    Full Text Available The electrical conductivity of leachates from imbibing seeds has been used as a vigor test for several species. The adaptation of this methodology to different species requires knowledge on the leaching kinetics of electrolytes. For Brazilwood seeds, the classic method was not satisfactory and rapid tests are essential because they have low storage capacity at room temperature. Leaching kinetics during seed imbibition is a function of physiological quality, presence or absence of seed coat, imbibing temperature and the initial moisture content of seed. In this study, the electrolyte leaching rate of six different categories of seeds, from two regions, was evaluated in seeds with and without seed coat and incubated with different moisture contents and at different temperatures. The results showed that the electrolyte leaching rate in Brazilwood seeds is independent of the physiological quality, the presence or absence of seed coat and imbibition temperature, but these factors changed the total amount of electrolytes leached. The leaching rate increased in the first few minutes of imbibition, suggesting that the adjustment of the methodology must consider the reduction in imbibition time, reduction in temperature, use of a controlled and slower pre-imbibition, and replacement of the imbibition solution after the first few minutes.

  8. Hormones and tomato seed germination

    NARCIS (Netherlands)

    Liu, Y.

    1996-01-01

    Using GA- and ABA-deficient mutants, exogenous gibberellins (GAs), abscisic acid (ABA) and osmoticum, we studied the roles of GAs and ABA in the induction of cell cycle activities, internal free space formation and changes in water relations during seed development and imbibition in tomato. First of

  9. Simulation of counter-current imbibition in water-wet fractured reservoirs based on discrete-fracture model

    Directory of Open Access Journals (Sweden)

    Wang Yueying

    2017-08-01

    Full Text Available Isolated fractures usually exist in fractured media systems, where the capillary pressure in the fracture is lower than that of the matrix, causing the discrepancy in oil recoveries between fractured and non-fractured porous media. Experiments, analytical solutions and conventional simulation methods based on the continuum model approach are incompetent or insufficient in describing media containing isolated fractures. In this paper, the simulation of the counter-current imbibition in fractured media is based on the discrete-fracture model (DFM. The interlocking or arrangement of matrix and fracture system within the model resembles the traditional discrete fracture network model and the hybrid-mixed-finite-element method is employed to solve the associated equations. The Behbahani experimental data validates our simulation solution for consistency. The simulation results of the fractured media show that the isolated-fractures affect the imbibition in the matrix block. Moreover, the isolated fracture parameters such as fracture length and fracture location influence the trend of the recovery curves. Thus, the counter-current imbibition behavior of media with isolated fractures can be predicted using this method based on the discrete-fracture model.

  10. seeds

    African Journals Online (AJOL)

    Owner

    peptidohydrolase (8.0%) from mung bean seedlings. (Baumgartner and Chrispeels, 1977), EP-HG (4.5%) from horse gram seedlings ( Rajeswari, 1997), acidic protease (15%) from germinating winged-bean seeds. (Usha and Singh, 1996) and EP-1 (1.6%) from barley seedlings and GA3-induced cysteine protease (3.38%).

  11. Direct Numerical Simulations of Dynamic Drainage and Imbibition to Investigate Capillary Pressure-Saturation-Interfacial Area Relation

    Science.gov (United States)

    Konangi, S.; Palakurthi, N. K.; Karadimitriou, N.; Comer, K.; Ghia, U.

    2017-12-01

    We present results of pore-scale direct numerical simulations (DNS) of drainage and imbibition in a quasi-two-dimensional (40µm thickness) porous medium with a randomly distributed packing of cylindrical obstructions. The Navier-Stokes (NS) equations are solved in the pore space on an Eulerian mesh using the open-source finite-volume computational fluid dynamics (CFD) code, OpenFOAM. The Volume-of-Fluid (VOF) method is employed to track the evolution of the fluid-fluid interface; a static contact angle is used to account for wall adhesion. From the DNS data, we focus on the macroscopic capillary pressure-saturation (Pc-Sw) relation, which is known to be hysteretic, i.e., this relation is flow process (such as drainage, imbibition and scanning curves) and history dependent. In order to overcome the problem of hysteresis, extended theories of multiphase flow hypothesized that the inclusion of specific interfacial area as a state variable will result in a unique relation between capillary pressure, saturation and interfacial area (Pc-Sw-awn). We study the role of specific interfacial area on hysteresis in the macroscopic Pc-Sw relation under non-equilibrium (dynamic) conditions. Under dynamic conditions, capillary pressure depends on the rate of change of the wetting phase saturation, and the dynamic Pc-Sw relation includes the changes caused by viscous effects. Simulations of drainage and imbibition are performed for two capillary numbers by controlling the flow rate of the non-wetting (polydimenthlysiloxane oil) and wetting (water) fluids. From these simulations, the Pc-Sw curves will be estimated; the Pc-S-awn surface will be constructed to determine whether the data points from drainage and imbibition processes fall on a unique surface under transient conditions. Different macroscopic capillary pressure definitions based on phase-averaged pressures and interfacial area will be evaluated. Understanding macroscopic capillary pressure definitions and the uniqueness

  12. (Cicer arietinum L.) seeds during germination by NMR spectroscopy

    African Journals Online (AJOL)

    Experiments were conducted to characterize the changes in water status during imbibition by nuclear magnetic resonance (NMR) spectroscopy in chickpea seeds exposed to static magnetic fields of 100 mT for 1 h. Water uptake during seed germination showed three phases with rapid initial hydration phase I, followed by ...

  13. Modeling of gravity-imbibition and gravity-drainage processes: Analytic and numerical solutions

    DEFF Research Database (Denmark)

    Bech, N.; Jensen, O.K.; Nielsen, B.

    1991-01-01

    A matrix/fracture exchange model for a fractured reservoir simulator is described. Oil/water imbibition is obtained from a diffusion equation with water saturation as the dependent variable. Gas/oil gravity drainage and imbibition are calculated by taking into account the vertical saturation...... distribution in the matrix blocks....

  14. Imbibitional damage in conidia of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Metarhizium acridum

    Science.gov (United States)

    When dried organisms are immersed in water, rapid imbibition may cause severe damage to plasma membranes; in unicellular organisms, such damage is usually lethal. This study investigated effects of pre-immersion moisture levels and immersion temperature on imbibitional damage in three insect pathoge...

  15. Seed reserve composition and mobilization during germination and early seedling establishment of Cereus jamacaru D.C. ssp. jamacaru (Cactaceae).

    Science.gov (United States)

    Alencar, Nara L M; Innecco, Renato; Gomes-Filho, Enéas; Gallão, Maria Izabel; Alvarez-Pizarro, Juan C; Prisco, José T; Oliveira, Alexandre B De

    2012-09-01

    Cereus jamacaru, a Cactaceae found throughout northeast Brazil, is widely used as cattle food and as an ornamental and medicinal plant. However, there has been little information about the physiological and biochemical aspects involved in its germination. The aim of this study was to investigate its reserve mobilization during germination and early seedling growth. For this, C. jamacaru seeds were germinated in a growth chamber and collected at 0, 2, 4, 5, 6, 8 and 12 days after imbibition for morphological and biochemical analyses. Dry seeds had wrinkled seed coats and large, curved embryos. Lipids were the most abundant reserve, comprising approximately 55% and 65% of the dry mass for cotyledons and the hypocotylradicle axis, respectively. Soluble sugars and starch were the minor reserves, corresponding to approximately 2.2% of the cotyledons' dry mass, although their levels showed significant changes during germination. Soluble proteins corresponded to 40% of the cotyledons' dry mass, which was reduced by 81% at the final period of germination compared to dry seeds. C. jamacaru seed can be classified as an oil seed due to its high lipid content. Moreover, lipids were the main reserve mobilized during germination because their levels were strongly reduced after seed germination, while proteins were the second most utilized reserve in this process.

  16. Effects of Gravity and Inlet/Outlet Location on a Two-Phase Cocurrent Imbibition in Porous Media

    Directory of Open Access Journals (Sweden)

    M. F. El-Amin

    2011-01-01

    Full Text Available We introduce 2D numerical investigations of the problem of gravity and inlet/outlet location effects of water-oil two-phase cocurrent imbibition in a porous medium. Three different cases of side-, top-, and bottom-inlet location are considered. Two-dimensional computations are carried out using the finite element method. Intensive comparisons are done between considering and neglecting gravity effect on water saturation, pressures of water and oil as well as water velocity. Results are introduced either in curves or as 2D visualization graphs. The results indicate that the buoyancy effects due to gravity force take place depending on inlet location. So, the buoyancy force in the momentum equations of the co-current imbibition model cannot be neglected as done by several previous studies. Also, we note that the 2D zero gravity model has a uniform flow and may be represented as 1D flow unlike the 2D nonzero gravity model showing a nonuniform flow.

  17. Effects of gravity and inlet/outlet location on a two-phase cocurrent imbibition in porous media

    KAUST Repository

    El-Amin, Mohamed

    2011-01-01

    We introduce 2D numerical investigations of the problem of gravity and inlet/outlet location effects of water-oil two-phase cocurrent imbibition in a porous medium. Three different cases of side-, top-, and bottom-inlet location are considered. Two-dimensional computations are carried out using the finite element method. Intensive comparisons are done between considering and neglecting gravity effect on water saturation, pressures of water and oil as well as water velocity. Results are introduced either in curves or as 2D visualization graphs. The results indicate that the buoyancy effects due to gravity force take place depending on inlet location. So, the buoyancy force in the momentum equations of the co-current imbibition model cannot be neglected as done by several previous studies. Also, we note that the 2D zero gravity model has a uniform flow and may be represented as 1D flow unlike the 2D nonzero gravity model showing a nonuniform flow. Copyright 2011 M. F. El-Amin and Shuyu Sun.

  18. A Dynamic Pore-Scale Model of Imbibition

    DEFF Research Database (Denmark)

    Mogensen, Kristian; Stenby, Erling Halfdan

    1998-01-01

    We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis...... of the above-mentioned parameters, except the viscosity ratio. We find that contact angle, aspect ratio and capillary number all have a significant influence on the competition between piston-like advance, leading to high recovery, and snap-off, causing oil entrapment. Due to enormous CPU-time requirements we...... been entirely inhibited, in agreement with results obtained by Blunt using a quasi-static model. For higher aspect ratios, the effect of rate and contact angle is more pronounced. Many core floods are conducted at capillary numbers in the range 10 to10.6. We believe that the excellent recoveries...

  19. GERMINATION STUDIES ON Tabebuia impetiginosa Mart. SEEDS

    Directory of Open Access Journals (Sweden)

    Edvaldo Aparecido Amaral da Silva

    2004-06-01

    Full Text Available Seed germination and seedling production of native forest tree species are an important step in ex situ conservation programs and in the reforestation with ecological purposes. Therefore, understanding seed germination and its regulation is mandatory for the complete success of the conservation programs and revegetation techniques. Thus, morphological studies, temperature requirements for seed germination and its control by gibberellins (GAs were studied in Tabebuia impetiginosa (“ipê-roxo” seeds. The best temperature for germination under constant light was 30oC. The imbibition of T. impetiginosa seeds followed the common triphasic pattern, with most of the seeds attaining phase II at 24 hours and phase III at 72 hours of imbibition. Visible germination, as radicle elongation, started at 30 hours in water-imbibed seeds and at 24 hours in GA-imbibed seeds. Seeds imbibed in Paclobutrazol, an inhibitor of GA biosynthesis, failed to germinate. However, application of exogenous gibberellins overcame inhibition and allowed germination, suggesting that GAs are regulators of Tabebuia impetiginosa seed germination. The results suggested that germination in Tabebuia impetiginosa seeds is controlled by elongation of the radicle and gibberellins may play an important role in regulating it. The possible role of gibberellins is discussed.

  20. Local evolution of seed flotation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Susana Saez-Aguayo

    2014-03-01

    Full Text Available Arabidopsis seeds rapidly release hydrophilic polysaccharides from the seed coat on imbibition. These form a heavy mucilage layer around the seed that makes it sink in water. Fourteen natural Arabidopsis variants from central Asia and Scandinavia were identified with seeds that have modified mucilage release and float. Four of these have a novel mucilage phenotype with almost none of the released mucilage adhering to the seed and the absence of cellulose microfibrils. Mucilage release was modified in the variants by ten independent causal mutations in four different loci. Seven distinct mutations affected one locus, coding the MUM2 β-D-galactosidase, and represent a striking example of allelic heterogeneity. The modification of mucilage release has thus evolved a number of times independently in two restricted geographical zones. All the natural mutants identified still accumulated mucilage polysaccharides in seed coat epidermal cells. Using nuclear magnetic resonance (NMR relaxometry their production and retention was shown to reduce water mobility into internal seed tissues during imbibition, which would help to maintain seed buoyancy. Surprisingly, despite released mucilage being an excellent hydrogel it did not increase the rate of water uptake by internal seed tissues and is more likely to play a role in retaining water around the seed.

  1. Mycoflora in Exhumed Seeds of Opuntia tomentosa and Its Possible Role in Seed Germination

    Directory of Open Access Journals (Sweden)

    María Esther Sánchez-Coronado

    2011-01-01

    Full Text Available The funicular cover of the Opuntia tomentosa seed limits imbibition; germination occurs only when the funicle is weakened or the funicular valve is removed. We investigated the role of fungi in funicular weakening and seed germination. Seeds that had been either buried in one of two sites or stored in the laboratory were germinated with and without a valve. Disinfected or nondisinfected seeds and their naked embryos were cultivated on agar or PDA. None of the 11 identified fungal genera grew on the disinfected control seeds or the embryos. The mycoflora present on disinfected and nondisinfected exhumed seeds suggest that the fungal colonization occurred in the soil and differed between the burial sites. Exhumed seeds with and without a valve germinated in high percentages, whereas only the control seeds without a valve germinated. Scanning electron micrographs showed that the hyphae penetrated, cracked, and eroded the funicular envelope of exhumed seeds.

  2. Radiation effects on Brassica seeds and seedlings

    Science.gov (United States)

    Deoli, Naresh; Hasenstein, Karl H.

    2016-07-01

    Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue

  3. Overcoming dormancy and enhancing germination of Sphaeralcea munroana seeds

    Science.gov (United States)

    Olga A. Kildisheva; R. Kasten Dumroese; Anthony S. Davis

    2011-01-01

    The results of a series of experiments involving a variety of dormancy-breaking treatments indicate that Munro's globemallow [Sphaeralcea munroana (Douglas) Spach] seeds are physically dormant, possess a cap-like structure in the occlusion of the water gap, which inhibits imbibition, and can be artificially dislodged through boiling water scarification. The...

  4. Fractal analysis of fracture increasing spontaneous imbibition in porous media with gas-saturated

    KAUST Repository

    Cai, Jianchao; Sun, Shuyu

    2013-01-01

    Spontaneous imbibition (SI) of wetting liquid into matrix blocks due to capillary pressure is regarded as an important recovery mechanism in low permeability fractured reservoir. In this paper, an analytical model is proposed for characterizing SI horizontally from a single plane fracture into gas-saturated matrix blocks. The presented model is based on the fractal character of pores in porous matrix, with gravity force included in the entire imbibition process. The accumulated mass of wetting liquid imbibed into matrix blocks is related to a number of factors such as contact area, pore fractal dimension, tortuosity, maximum pore size, porosity, liquid density and viscosity, surface tension, contact angle, as well as height and tilt angle of the fracture. The mechanism of fracture-enhanced SI is analyzed accordingly. Because of the effect of fracture, the gravity force is positive to imbibition process. Additionally, the farther away from the fracture top of the pore, the more influential the hydrostatic pressure is upon the imbibition action. The presented fractal analysis of horizontal spontaneous imbibition from a single fracture could also shed light on the scaling study of the mass transfer function between matrix and fracture system of fractured reservoirs. © 2013 World Scientific Publishing Company.

  5. Fractal analysis of fracture increasing spontaneous imbibition in porous media with gas-saturated

    KAUST Repository

    Cai, Jianchao

    2013-08-01

    Spontaneous imbibition (SI) of wetting liquid into matrix blocks due to capillary pressure is regarded as an important recovery mechanism in low permeability fractured reservoir. In this paper, an analytical model is proposed for characterizing SI horizontally from a single plane fracture into gas-saturated matrix blocks. The presented model is based on the fractal character of pores in porous matrix, with gravity force included in the entire imbibition process. The accumulated mass of wetting liquid imbibed into matrix blocks is related to a number of factors such as contact area, pore fractal dimension, tortuosity, maximum pore size, porosity, liquid density and viscosity, surface tension, contact angle, as well as height and tilt angle of the fracture. The mechanism of fracture-enhanced SI is analyzed accordingly. Because of the effect of fracture, the gravity force is positive to imbibition process. Additionally, the farther away from the fracture top of the pore, the more influential the hydrostatic pressure is upon the imbibition action. The presented fractal analysis of horizontal spontaneous imbibition from a single fracture could also shed light on the scaling study of the mass transfer function between matrix and fracture system of fractured reservoirs. © 2013 World Scientific Publishing Company.

  6. Improved Oil Recovery in Chalk. Spontaneous Imbibition affected by Wettability, Rock Framework and Interfacial Tension

    Energy Technology Data Exchange (ETDEWEB)

    Milter, J.

    1996-12-31

    The author of this doctoral thesis aims to improve the oil recovery from fractured chalk reservoirs, i.e., maximize the area of swept zones and their displacement efficiencies. In order to identify an improved oil recovery method in chalk, it is necessary to study wettability of calcium carbonate and spontaneous imbibition potential. The thesis contains an investigation of thin films and wettability of single calcite surfaces. The results of thin film experiments are used to evaluate spontaneous imbibition experiments in different chalk types. The chalk types were described detailed enough to permit considering the influence of texture, pore size and pore throat size distributions, pore geometry, and surface roughness on wettability and spontaneous imbibition. Finally, impacts of interfacial tension by adding anionic and cationic surfactants to the imbibing water phase are studied at different wettabilities of a well known chalk material. 232 refs., 97 figs., 13 tabs.

  7. Depth of dormancy in tomato seeds is related to the progression of the cell cycle prior to its induction

    NARCIS (Netherlands)

    Castro, de R.D.; Lammeren, van A.A.M.; Groot, S.P.C.; Bino, R.J.; Hilhorst, H.W.M.

    2001-01-01

    Cell cycle activities are initiated following imbibition of non-dormant seeds. However, it is not known whether cell cycle related events other than DNA replication also remain suppressed in imbibed dormant seeds. The objective of this study was to demonstrate that the transitions between the

  8. Changes in DNa and microtubules during loss and re-establishment of desiccation tolerance in germinating Medicago truncatula seeds

    NARCIS (Netherlands)

    Faria, J.M.R.; Buitink, J.; Lammeren, van A.A.M.; Hilhorst, H.W.M.

    2005-01-01

    Desiccation tolerance (DT) in orthodox seeds is acquired during seed development and lost upon imbibition/germination, purportedly upon the resumption of DNA synthesis in the radicle cells. In the present study, flow cytometric analyses and visualization of microtubules (MTs) in radicle cells of

  9. Effects of gravity and inlet location on a two-phase countercurrent imbibition in porous media

    KAUST Repository

    El-Amin, Mohamed; Salama, Amgad; Sun, S.

    2012-01-01

    We introduce a numerical investigation of the effect of gravity on the problem of two-phase countercurrent imbibition in porous media. We consider three cases of inlet location, namely, from, side, top, and bottom. A 2D rectangular domain is considered for numerical simulation. The results indicate that gravity has a significant effect depending on open-boundary location.

  10. The Seed Proteome Web Portal

    Directory of Open Access Journals (Sweden)

    Marc eGalland

    2012-06-01

    Full Text Available The Seed Proteome Web Portal (SPWP; http://www.seedproteome.com/ gives access to information both on quantitative seed proteomic data and on seed-related protocols. Firstly, the SPWP provides access to the 475 different Arabidopsis seed proteins annotated from 2 dimensional electrophoresis (2DE maps. Quantitative data are available for each protein according to their accumulation profile during the germination process. These proteins can be retrieved either in list format or directly on scanned 2DE maps. These proteomic data reveal that 40% of seed proteins maintain a stable abundance over germination, up to radicle protrusion. During sensu stricto germination (24 h upon imbibition about 50% of the proteins display quantitative variations, exhibiting an increased abundance (35% or a decreasing abundance (15%. Moreover, during radicle protrusion (24 h to 48 h upon imbibition, 41% proteins display quantitative variations with an increased (23% or a decreasing abundance (18%. In addition, an analysis of the seed proteome revealed the importance of protein post-translational modifications as demonstrated by the poor correlation (r2 = 0.29 between the theoretical (predicted from Arabidopsis genome and the observed protein isoelectric points. Secondly, the SPWP is a relevant technical resource for protocols specifically dedicated to Arabidopsis seed proteome studies. Concerning 2D electrophoresis, the user can find efficient procedures for sample preparation, electrophoresis coupled with gel analysis and protein identification by mass spectrometry, which we have routinely used during the last 12 years. Particular applications such as the detection of oxidized proteins or de novo synthetized proteins radiolabeled by [35S]-methionine are also given in great details. Future developments of this portal will include proteomic data from studies such as dormancy release and protein turnover through de novo protein synthesis analyses during germination.

  11. Dynamic pore-scale network model (PNM) of water imbibition in porous media

    Science.gov (United States)

    Li, J.; McDougall, S. R.; Sorbie, K. S.

    2017-09-01

    A dynamic pore-scale network model is presented which simulates 2-phase oil/water displacement during water imbibition by explicitly modelling intra-pore dynamic bulk and film flows using a simple local model. A new dynamic switching parameter, λ, is proposed within this model which is able to simulate the competition between local capillary forces and viscous forces over a very wide range of flow conditions. This quantity (λ) determines the primary pore filling mechanism during imbibition; i.e. whether the dominant force is (i) piston-like displacement under viscous forces, (ii) film swelling/collapse and snap-off due to capillary forces, or (iii) some intermediate local combination of both mechanisms. A series of 2D dynamic pore network simulations is presented which shows that the λ-model can satisfactorily reproduce and explain different filling regimes of water imbibition over a wide range of capillary numbers (Ca) and viscosity ratios (M). These imbibition regimes are more complex than those presented under drainage by (Lenormand et al. (1983)), since they are determined by a wider group of control parameters. Our simulations show that there is a coupling between viscous and capillary forces that is much less important in drainage. The effects of viscosity ratio during imbibition are apparent even under conditions of very slow flow (low Ca)-displacements that would normally be expected to be completely capillary dominated. This occurs as a result of the wetting films having a much greater relative mobility in the higher M cases (e.g. M = 10) thus leading to a higher level of film swelling/snap-off, resulting in local oil cluster bypassing and trapping, and hence a poorer oil recovery. This deeper coupled viscous mechanism is the underlying reason why the microscopic displacement efficiency is lower for higher M cases in water imbibition processes. Additional results are presented from the dynamic model on the corresponding effluent fractional flows (fw

  12. Hidrocondicionamento de Parkia pendula [Benth ex Walp]: sementes com dormência física de árvore da Amazônia Hydropriming of Parkia pendula [Penth. ex Walp.]: seeds with physical dormancy from Amazon tree

    Directory of Open Access Journals (Sweden)

    Gina Janet Vargas Pinedo

    2008-02-01

    4 to 28 hours to reach the desired imbibition degrees (20, 40, 60, 80 and 90%. Seeds were then sown immediately in washed sand in the nursery (4 x 25 seeds / treatment or dried for 7 days (24±2°C and 68±3% R.H.. Unstored and unprimed (control seeds showed 59±8.9% germination, which was less than that of stored unprimed seeds (76±11.3 %. Submersion periods exceeding 13 hours reduced germination relative to unprimed seeds. After 4 hours of submersion (seed moisture 26-31%, both unstored and stored seeds increased their performance. Even higher improvement was verified when drying followed submersion. Thus, the positive effects of priming occurred in phase I of the imbibition curve. Hydropriming of 4 hours at 15 ºC was found to be a simple and inexpensive method for P. pendula seeds since it increased seedling development velocity, brought the germination percentage of unstored seeds to a level similar to that of stored seeds and increased germination synchronization of stored seeds.

  13. Depth of dormancy in tomato (Lycopersicon esculentum Mill.) seeds is related to the progression of the cell cycle prior to the induction of dormancy

    NARCIS (Netherlands)

    Castro, de R.D.; Bino, R.J.; Jing, H.C.; Hilhorst, H.W.M.

    2001-01-01

    Cell cycle activities are initiated following imbibition of non-dormant seeds. However, it is not known whether cell cycle related events other than DNA replication also remain suppressed in imbibed dormant seeds. The objective of this study was to demonstrate that the transitions between the

  14. Mobilization and Role of Starch, Protein, and Fat Reserves during Seed Germination of Six Wild Grassland Species.

    Science.gov (United States)

    Zhao, Ming; Zhang, Hongxiang; Yan, Hong; Qiu, Lu; Baskin, Carol C

    2018-01-01

    Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species ( Chloris virgata , Kochia scoparia , Lespedeza hedysaroides , Astragalus adsurgens , Leonurus artemisia , and Dracocephalum moldavica ) and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed), but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species.

  15. Mobilization and Role of Starch, Protein, and Fat Reserves during Seed Germination of Six Wild Grassland Species

    Directory of Open Access Journals (Sweden)

    Ming Zhao

    2018-02-01

    Full Text Available Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species (Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed, but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species.

  16. Optimization of seed germination in an Iranian serpentine endemic, Fortuynia garcinii

    NARCIS (Netherlands)

    Salehi Eskandari, Behrooz; Ghaderian, Seyed Majid; Ghasemi, Rasoul; Schat, Henk

    2017-01-01

    Fortuynia garcinii (Brassicaceae) is endemic to serpentine soils in central Iran. It has indehiscent silicles. The effects of its fruit pericarp on seed imbibition and germination were determined. The effects of moist chilling (15 days) and gibberellic acid (GA3, four levels), both alone and

  17. Spontaneous imbibition in fractal tortuous micro-nano pores considering dynamic contact angle and slip effect: phase portrait analysis and analytical solutions.

    Science.gov (United States)

    Li, Caoxiong; Shen, Yinghao; Ge, Hongkui; Zhang, Yanjun; Liu, Tao

    2018-03-02

    Shales have abundant micro-nano pores. Meanwhile, a considerable amount of fracturing liquid is imbibed spontaneously in the hydraulic fracturing process. The spontaneous imbibition in tortuous micro-nano pores is special to shale, and dynamic contact angle and slippage are two important characteristics. In this work, we mainly investigate spontaneous imbibition considering dynamic contact angle and slip effect in fractal tortuous capillaries. We introduce phase portrait analysis to analyse the dynamic state and stability of imbibition. Moreover, analytical solutions to the imbibition equation are derived under special situations, and the solutions are verified by published data. Finally, we discuss the influences of slip length, dynamic contact angle and gravity on spontaneous imbibition. The analysis shows that phase portrait is an ideal tool for analysing spontaneous imbibition because it can evaluate the process without solving the complex governing ordinary differential equations. Moreover, dynamic contact angle and slip effect play an important role in fluid imbibition in fractal tortuous capillaries. Neglecting slip effect in micro-nano pores apparently underestimates imbibition capability, and ignoring variations in contact angle causes inaccuracy in predicting imbibition speed at the initial stage of the process. Finally, gravity is one of the factors that control the stabilisation of the imbibition process.

  18. Response of Physiological Growth Indices and Bulb Dry Yield of Onion (Allium cepa L. Genotypes to Priming and Seed Size

    Directory of Open Access Journals (Sweden)

    M. Izadkhah

    2016-02-01

    Full Text Available Introduction Priming is one of the most common methods of improving seed quality, which significantly affects their storability. Seed priming is a seed treatment that allows imbibition and activation of the initial metabolic events associated with seed germination, but prevents radicle emergence and growth. In other words, phase one and two of seed water imbibition curve are passed, but seeds do not enter the third phase of water uptake. Then seeds are dried back to their original water content. Seed priming is a pre-sowing strategy for influencing seed germination and seedling development by modulating pre-germination metabolic activity prior to emergence of the radicle and generally enhances germination rate and plant performance. Naturally, when speed and percentage emergence of germinating seeds are being high, growing sources like light, water and nutrient will be more used. Another factor that can affect the seed germination and seedling establishment is the seed size. As generally known, among producing factors, seed as the first consumer store, plays an important role in the transfer of genetic characters and improvement of qualitative and quantitative traits of production. One of the most important factors in maximizing crop yield is planting high quality seed. Seed size is an important physical indicator of seed quality that affects vegetative growth and is frequently related to yield, market grade factors and harvest efficiency. In the present paper, effects of different pre-sowing treatments and seed size on physiological growth indices and bulb dry yield of onion cultivars were investigated. Materials and Methods In order to determine the response of physiological growth indices and bulb dry yield of onion to priming and seed size, a field experiment was conducted in 2012-2013 cropping season at Agriculture and Natural Resources Research Center of East, Azarbayjan, Iran. This experiment was a factorial experiment based on a

  19. A generalized power-law scaling law for a two-phase imbibition in a porous medium

    KAUST Repository

    El-Amin, Mohamed

    2013-11-01

    Dimensionless time is a universal parameter that may be used to predict real field behavior from scaled laboratory experiments in relation to imbibition processes in porous media. Researchers work to nondimensionalize the time has been through the use of parameters that are inherited to the properties of the moving fluids and the porous matrix, which may be applicable to spontaneous imbibition. However, in forced imbibition, the dynamics of the process depends, in addition, on injection velocity. Therefore, we propose the use of scaling velocity in the form of a combination of two velocities, the first of which (the characteristic velocity) is defined by the fluid and the porous medium parameters and the second is the injection velocity, which is a characteristic of the process. A power-law formula is suggested for the scaling velocity such that it may be used as a parameter to nondimensionalize time. This may reduce the complexities in characterizing two-phase imbibition through porous media and works well in both the cases of spontaneous and forced imbibition. The proposed scaling-law is tested against some oil recovery experimental data from the literature. In addition, the governing partial differential equations are nondimensionalized so that the governing dimensionless groups are manifested. An example of a one-dimensional countercurrent imbibition is considered numerically. The calculations are carried out for a wide range of Ca and Da to illustrate their influences on water saturation as well as relative water/oil permeabilities. © 2013 Elsevier B.V.

  20. Spontaneous imbibition of water and determination of effective contact angles in the Eagle Ford Shale Formation using neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    DiStefano, Victoria H.; Cheshire, Michael C.; McFarlane, Joanna; Kolbus, Lindsay M.; Hale, Richard E.; Perfect, Edmund; Bilheux, Hassina Z.; Santodonato, Louis J.; Hussey, Daniel S.; Jacobson, David L.; LaManna, Jacob M.; Bingham, Philip R.; Starchenko, Vitaliy; Anovitz, Lawrence M.

    2017-10-01

    Understanding of fundamental processes and prediction of optimal parameters during the horizontal drilling and hydraulic fracturing process results in economically effective improvement of oil and natural gas extraction. Although, the modern analytical and computational models can capture fracture growth, there is a lack of experimental data on spontaneous imbibition and wettability in oil and gas reservoirs for the validation of further model development. In this work, we used neutron imaging to measure the spontaneous imbibition of water into fractures of Eagle Ford Shale with known geometries and fracture orientations. An analytical solution for a set of nonlinear second-order differential equations was applied to the measured imbibition data to determine effective contact angles. The analytical solution fit the measured imbibition data reasonably well and determined effective contact angles were slightly higher than static contact angles due to effects of in-situ changes in velocity, surface roughness, and heterogeneity of mineral surfaces on the fracture surface. Additionally, small fracture widths may have retarded imbibition and affected model fits, which suggests that average fracture widths are not satisfactory for modeling imbibition in natural systems.

  1. A generalized power-law scaling law for a two-phase imbibition in a porous medium

    KAUST Repository

    El-Amin, Mohamed; Salama, Amgad; Sun, Shuyu

    2013-01-01

    Dimensionless time is a universal parameter that may be used to predict real field behavior from scaled laboratory experiments in relation to imbibition processes in porous media. Researchers work to nondimensionalize the time has been through the use of parameters that are inherited to the properties of the moving fluids and the porous matrix, which may be applicable to spontaneous imbibition. However, in forced imbibition, the dynamics of the process depends, in addition, on injection velocity. Therefore, we propose the use of scaling velocity in the form of a combination of two velocities, the first of which (the characteristic velocity) is defined by the fluid and the porous medium parameters and the second is the injection velocity, which is a characteristic of the process. A power-law formula is suggested for the scaling velocity such that it may be used as a parameter to nondimensionalize time. This may reduce the complexities in characterizing two-phase imbibition through porous media and works well in both the cases of spontaneous and forced imbibition. The proposed scaling-law is tested against some oil recovery experimental data from the literature. In addition, the governing partial differential equations are nondimensionalized so that the governing dimensionless groups are manifested. An example of a one-dimensional countercurrent imbibition is considered numerically. The calculations are carried out for a wide range of Ca and Da to illustrate their influences on water saturation as well as relative water/oil permeabilities. © 2013 Elsevier B.V.

  2. Effect of the meniscus contact angle during early regimes of spontaneous imbibition in nanochannels.

    Science.gov (United States)

    Karna, Nabin Kumar; Oyarzua, Elton; Walther, Jens H; Zambrano, Harvey A

    2016-11-30

    Nanoscale capillarity has been extensively investigated; nevertheless, many fundamental questions remain open. In spontaneous imbibition, the classical Lucas-Washburn equation predicts a singularity as the fluid enters the channel consisting of an anomalous infinite velocity of the capillary meniscus. Bosanquet's equation overcomes this problem by taking into account fluid inertia predicting an initial imbibition regime with constant velocity. Nevertheless, the initial constant velocity as predicted by Bosanquet's equation is much greater than those observed experimentally. In the present study, large scale atomistic simulations are conducted to investigate capillary imbibition of water in slit silica nanochannels with heights between 4 and 18 nm. We find that the meniscus contact angle remains constant during the inertial regime and its value depends on the height of the channel. We also find that the meniscus velocity computed at the channel entrance is related to the particular value of the meniscus contact angle. Moreover, during the subsequent visco-inertial regime, as the influence of viscosity increases, the meniscus contact angle is found to be time dependent for all the channels under study. Furthermore, we propose an expression for the time evolution of the dynamic contact angle in nanochannels which, when incorporated into Bosanquet's equation, satisfactorily explains the initial capillary rise.

  3. Soaking curve and effect of temperature on the germination of daisy seeds Curva de embebição e efeito da temperatura na germinação de sementes de margarida

    Directory of Open Access Journals (Sweden)

    Rogério G Pêgo

    2012-06-01

    Full Text Available The soaking curve and the effect of temperature on the germination of daisy seeds (Chrysanthemum leucanthemum were characterized in this study. To determine the soaking curve, four samples of 0.5 g of seeds were soaked in germitest paper moistened with distilled water and maintained in germinator at 25ºC. The seeds were weighed in periods of 0, 3, 6, 9, 12, 24, 36, 48, 60, 72, 84 and 96 hours using a precision digital balance of 0.0001 g. A triphasic pattern germination curve was adjusted, allowing the determination of the beginning and duration of the phase II of the germination process. The germination test was carried out with four replications of 50 seeds disposed in "Gerbox" boxes and placed in germinators at the temperatures of 20, 25, 30 or 20-30ºC. A completely randomized experimental design was used with four replications of 50 seeds. The data were submitted to the analysis of variance and the averages were compared by the Tukey test, at 5% of probability. For analysis of accumulated seed germination, regressions were adjusted based on period of experiment. The seeds presented a triphasic pattern of germination and the phases I and II lasted 12 and 48 hours, respectively. The best temperature for the germination of the seeds is 25ºC. The temperature of 30ºC promoted the thermoinhibition of germination and increased the dead and dormant seeds and abnormal seedlings.A curva de embebição e o efeito da temperatura sobre a germinação de sementes de margarida (Chrysanthemum leucanthemum foram caracterizados. Para determinar a curva de embebição, quatro amostras de 0,5 g de sementes foram embebidas em papel germitest umedecido com água destilada e mantidas em germinador a 25ºC. As sementes foram pesadas em períodos de 0, 3, 6, 9, 12, 24, 36, 48, 60, 72, 84 e 96 horas, com auxílio de balança de precisão digital de 0,0001 g. Foi ajustada uma curva trifásica padrão de germinação, permitindo a determinação do início e a dura

  4. Proteome analysis of dissected barley seed tissue during germination and radicle elongation

    DEFF Research Database (Denmark)

    Bønsager, Birgit Christine

    2007-01-01

    at the protein or the DNA level. In addition, germination of barley seeds is of interest for the brewing industry since this process corresponds to the steeping process that starts the industrial malting. In the present study a proteomics approach was employed to understand the initial changes in the water...... soluble protein composition of the barley seed upon imbibition and the following events that occur until to 72 h post imbibition (PI). 2D gel electrophoresis of proteins extracted from dissected barley seeds tissues during germination (0-24 h) and the subsequent radicle elongation (24-72 h) describes...... spatio-temporal variations in the protein patterns. Seeds from 8 time points (0, 4, 12, 24, 36, 52, 60, and 72 h PI) were dissected into embryo, aleurone layer and endosperm and small scale protein extractions enabled us to obtain good resolution 2D gels. The 2D gels were compared between the time points...

  5. Protein synthesis in the embryo of Pinus thunbergii seed, 2

    International Nuclear Information System (INIS)

    Yamamoto, Naoaki; Sasaki, Satohiko.

    1977-01-01

    14 C-Amino acid incorporating activity in the absence of exogenous mRNA was found in a cell-free system from embryos of light-germinated Pinus thunbergii seeds, but not in that from dark-imbibed seed embryos. Template activity in the cell-free system from the light-germinated seed embryos was observed in the ribosome fraction, especially the polyribosome fraction, but not in the 100,000 x g supernatant fraction (s100). These facts suggest that the nature of the block in protein synthesis during the imbibition of seeds in the dark is due to the lack or inactivity of mRNA. The s100 from light-germinated seed embryos was found to be less active in amino acid incorporation than that from dark-imbibed seed embryos. (auth.)

  6. Seed germination, seedling traits, and seed bank of the tree Moringa peregrina (Moringaceae) in a hyper-arid environment.

    Science.gov (United States)

    Gomaa, Nasr H; Picó, F Xavier

    2011-06-01

    Water-limited hot environments are good examples of hyper-aridity. Trees are scarce in these environments but some manage to survive, such as the tree Moringa peregrina. Understanding how trees maintain viable populations in extremely arid environments may provide insight into the adaptive mechanisms by which trees cope with extremely arid weather conditions. This understanding is relevant to the current increasing aridity in several regions of the world. Seed germination experiments were conducted to assess variation in seed mass, seed germination, and seedling traits of Moringa peregrina plants and the correlations among these traits. A seed burial experiment was also designed to study the fate of M. peregrina seeds buried at two depths in the soil for two time periods. On average, seeds germinated in three days and seedling shoots grew 0.7 cm per day over three weeks. Larger seeds decreased germination time and increased seedling growth rates relative to smaller seeds. Seeds remained quiescent in the soil and germination was very high at both depths and burial times. The after-ripening time of Moringa peregrina seeds is short and seeds germinate quickly after imbibition. Plants of M. peregrina may increase in hyper-arid environments from seeds with larger mass, shorter germination times, and faster seedling growth rates. The results also illustrate the adjustment in allocation to seed biomass and correlations among seed and seedling traits that allows M. peregrina to be successful in coping with aridity in its environment.

  7. Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Standnes, Dag Chun

    2001-09-01

    The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

  8. Estimation of relative permeability and capillary pressure from mass imbibition experiments

    Science.gov (United States)

    Alyafei, Nayef; Blunt, Martin J.

    2018-05-01

    We perform spontaneous imbibition experiments on three carbonates - Estaillades, Ketton, and Portland - which are three quarry limestones that have very different pore structures and span wide range of permeability. We measure the mass of water imbibed in air saturated cores as a function of time under strongly water-wet conditions. Specifically, we perform co-current spontaneous experiments using a highly sensitive balance to measure the mass imbibed as a function of time for the three rocks. We use cores measuring 37 mm in diameter and three lengths of approximately 76 mm, 204 mm, and 290 mm. We show that the amount imbibed scales as the square root of time and find the parameter C, where the volume imbibed per unit cross-sectional area at time t is Ct1/2. We find higher C values for higher permeability rocks. Employing semi-analytical solutions for one-dimensional flow and using reasonable estimates of relative permeability and capillary pressure, we can match the experimental data. We finally discuss how, in combination with conventional measurements, we can use theoretical solutions and imbibition measurements to find or constrain relative permeability and capillary pressure.

  9. Induction of 9-cis-epoxycarotenoid dioxygenase in Arabidopsis thaliana seeds enhances seed dormancy.

    Science.gov (United States)

    Martínez-Andújar, Cristina; Ordiz, M Isabel; Huang, Zhonglian; Nonogaki, Mariko; Beachy, Roger N; Nonogaki, Hiroyuki

    2011-10-11

    Full understanding of mechanisms that control seed dormancy and germination remains elusive. Whereas it has been proposed that translational control plays a predominant role in germination, other studies suggest the importance of specific gene expression patterns in imbibed seeds. Transgenic plants were developed to permit conditional expression of a gene encoding 9-cis-epoxycarotenoid dioxygenase 6 (NCED6), a rate-limiting enzyme in abscisic acid (ABA) biosynthesis, using the ecdysone receptor-based plant gene switch system and the ligand methoxyfenozide. Induction of NCED6 during imbibition increased ABA levels more than 20-fold and was sufficient to prevent seed germination. Germination suppression was prevented by fluridone, an inhibitor of ABA biosynthesis. In another study, induction of the NCED6 gene in transgenic seeds of nondormant mutants tt3 and tt4 reestablished seed dormancy. Furthermore, inducing expression of NCED6 during seed development suppressed vivipary, precocious germination of developing seeds. These results indicate that expression of a hormone metabolism gene in seeds can be a sole determinant of dormancy. This study opens the possibility of developing a robust technology to suppress or promote seed germination through engineering pathways of hormone metabolism.

  10. Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Yu Tian

    2014-01-01

    Full Text Available 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.

  11. Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

    Science.gov (United States)

    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 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.

  12. Seeds and plantlets of Myrciaria dubia “camu-camu”: biometry, germination, and initial growth

    Directory of Open Access Journals (Sweden)

    Anderson E. Medina Bardales

    2014-06-01

    Full Text Available The objectives were to determine seed biometrics, recording cellular respiration in the imbibition process, evaluate the effect of inducing chemicals in germination and early growth analysis. Cellular respiration during imbibition was measured by reduction of methylene blue and Janus Green B. The inductor effect of five chemical compounds in germination was evaluated. Initial growth was recorded by stereoscopic. Results showed that the seeds have an average weight of 520 ± 172 mg, length of 13.50 ± 1.76 mm, width of 10.61 ± 1.14 mm, and thickness of 4.68 ± 0 62 mm. These variables showed significant correlations (r of 0.494 to 0.897 and p 90% and 65% respectively. Seedling initial growth consisted of six stages and occurred over a period of 22 days after radicle emergence. In conclusion, M. dubia seeds show wide variation in their biometrics (weight, length, width and thickness, but show significant correlations with each other. Likewise, seeds are metabolically active in imbibition process, and germination is induced by sodium nitrite and potassium cyanide. Furthermore, seedling initial growth to occur over a period of 22 days after emergence of the radicle and consists of six distinct stages.

  13. A Dynamic Two-Phase Pore-Scale Model of Imbibition

    DEFF Research Database (Denmark)

    Mogensen, Kristian; Stenby, Erling Halfdan

    1998-01-01

    We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle, and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis...... of the above-mentioned parameters, except from the viscosity ratio. We find that contact angle, aspect ratio, and capillary number all have a significant influence on the competition between piston-lice advance, leading to high recovery, and snap-off, causing oil entrapment. Due to significant CPU......-off has been entirely inhibited, in agreement with results obtained by Blunt (1997) who used a quasi-static model. For higher aspect ratios, the effect of rate and contact angle is more pronounced....

  14. Effect of the meniscus contact angle during early regimes of spontaneous imbibition in nanochannels

    DEFF Research Database (Denmark)

    Karna, Nabin Kumar; Oyarzua, Elton; Walther, Jens Honore

    2016-01-01

    study, large scale atomistic simulations are conducted to investigate capillary imbibition of water in slit silica nanochannels with heights between 4 and 18 nm. We find that the meniscus contact angle remains constant during the inertial regime and its value depends on the height of the channel. We...... also find that the meniscus velocity computed at the channel entrance is related to the particular value of the meniscus contact angle. Moreover, during the subsequent visco-inertial regime, as the influence of viscosity increases, the meniscus contact angle is found to be time dependent for all...... the channels under study. Furthermore, we propose an expression for the time evolution of the dynamic contact angle in nanochannels which, when incorporated into Bosanquet's equation, satisfactorily explains the initial capillary rise....

  15. A Neutron Radiology Application to Natural Absorption (Imbibition) of Water into Porous Rocks

    International Nuclear Information System (INIS)

    Middleton, M.F.; de Beer, Frikkie

    2005-01-01

    Full text: Dynamic neutron radiology provides a method of evaluating the concentration of water in porous media. A study of water imbibition (absorption of a wetting liquid into a porous medium with a non-wetting fluid, air), which is imaged by dynamic neutron radiology , provides an excellent method of determining the fluid diffusivity parameter, D. This parameter enables one to model water-air regimes in surface hydrological systems and aquifers; analogies can also be made for deeper petroleum systems. A methodology of pixel-by-pixel analysis for the estimation of water concentration, as a function of time under natural absorption conditions, is proposed which provides a good mapping of D within a rock sample. The proposed method entails the discrete mapping of the differential equation for horizontal flow of a partial water concentration, c, in an air-filled rock/soil. (authors)

  16. Oxygen dependency of germinating Brassica seeds

    Science.gov (United States)

    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.

  17. Abscisic acid regulates seed germination of Vellozia species in response to temperature.

    Science.gov (United States)

    Vieira, B C; Bicalho, E M; Munné-Bosch, S; Garcia, Q S

    2017-03-01

    The relationship between the phytohormones, gibberellin (GA) and abscisic acid (ABA) and light and temperature on seed germination is still not well understood. We aimed to investigate the role of the ABA and GA on seed germination of Vellozia caruncularis, V. intermedia and V. alutacea in response to light/dark conditions on different temperature. Seeds were incubated in GA (GA 3 or GA 4 ) or ABA and their respective biosynthesis inhibitors (paclobutrazol - PAC, and fluridone - FLU) solutions at two contrasting temperatures (25 and 40 °C). Furthermore, endogenous concentrations of active GAs and those of ABA were measured in seeds of V. intermedia and V. alutacea during imbibition/germination. Exogenous ABA inhibited the germination of Vellozia species under all conditions tested. GA, FLU and FLU + GA 3 stimulated germination in the dark at 25 °C (GA 4 being more effective than GA 3 ). PAC reduced seed germination in V. caruncularis and V. alutacea, but did not affect germination of V. intermedia at 40 °C either under light or dark conditions. During imbibition in the dark, levels of active GAs decreased in the seeds of V. intermedia, but were not altered in those of V. alutacea. Incubation at 40 °C decreased ABA levels during imbibition in both V. caruncularis and V. alutacea. We conclude that the seeds of Vellozia species studied here require light or high temperature to germinate and ABA has a major role in the regulation of Vellozia seed germination in response to light and temperature. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. Molecular Dynamics Simulation of Spontaneous Imbibition in Nanopores and Recovery of Asphaltenic Crude Oils Using Surfactants for EOR Applications Simulations de dynamique moléculaire d’imbibition spontanée dans des nanopores et pour la récupération d’huiles brutes asphalténiques en utilisant des agents tensioactifs pour des applications d’EOR

    Directory of Open Access Journals (Sweden)

    Stukan M.R.

    2012-12-01

    Full Text Available We present Molecular Dynamics (MD simulations of the imbibition process in nanopores in case of two different mechanisms of the wettability modification. We compare the imbibition of an aqueous surfactant solution into an oil-wet pore driven by surfactant adsorption onto the oil-wet rock surface (coating mechanism and the imbibition of an aqueous surfactants solution driven by surfactants removing the contaminant molecules from the originally water-wet surface (cleaning mechanism. Our results show qualitative difference in the imbibition dynamics in these two cases and indicate that MD simulation is a useful tool to investigate details of the imbibition mechanisms at the pore scale with direct implications for Enhanced Oil Recovery (EOR operations. Nous presentons des simulations de Dynamique Moleculaire (DM du processus d’imbibition dans des nanopores dans le cas de deux mecanismes differents de modification de mouillabilite. Nous comparons l’imbibition d’une solution aqueuse d’agent tensioactif dans un pore mouille d’huile entrainee par une adsorption d’agent tensioactif sur la surface de roche mouillee d’huile (mecanisme de revetement et l’imbibition d’une solution aqueuse d’agent tensioactif entrainee par des agents tensioactifs eliminant les molecules contaminantes de la surface originellement mouillee d’eau (mecanisme de nettoyage. Nos resultats montrent une difference qualitative en matiere de dynamique d’imbibition dans ces deux cas et indiquent que la simulation de DM constitue un outil utile pour etudier les mecanismes d’imbibition a l’echelle des pores avec des implications directes pour des operations de recuperation renforcee d’huile (EOR, Enhanced Oil Recovery.

  19. WETTABILITY AND IMBIBITION: MICROSCOPIC DISTRIBUTION OF WETTING AND ITS CONSEQUENCES AT THE CORE AND FIELD SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Jill S. Buckley; Norman R. Morrow; Chris Palmer; Purnendu K. Dasgupta

    2003-02-01

    The questions of reservoir wettability have been approached in this project from three directions. First, we have studied the properties of crude oils that contribute to wetting alteration in a reservoir. A database of more than 150 different crude oil samples has been established to facilitate examination of the relationships between crude oil chemical and physical properties and their influence on reservoir wetting. In the course of this work an improved SARA analysis technique was developed and major advances were made in understanding asphaltene stability including development of a thermodynamic Asphaltene Solubility Model (ASM) and empirical methods for predicting the onset of instability. The CO-Wet database is a resource that will be used to guide wettability research in the future. The second approach is to study crude oil/brine/rock interactions on smooth surfaces. Contact angle measurements were made under controlled conditions on mica surfaces that had been exposed to many of the oils in the CO-Wet database. With this wealth of data, statistical tests can now be used to examine the relationships between crude oil properties and the tendencies of those oils to alter wetting. Traditionally, contact angles have been used as the primary wetting assessment tool on smooth surfaces. A new technique has been developed using an atomic forces microscope that adds a new dimension to the ability to characterize oil-treated surfaces. Ultimately we aim to understand wetting in porous media, the focus of the third approach taken in this project. Using oils from the CO-Wet database, experimental advances have been made in scaling the rate of imbibition, a sensitive measure of core wetting. Application of the scaling group to mixed-wet systems has been demonstrated for a range of core conditions. Investigations of imbibition in gas/liquid systems provided the motivation for theoretical advances as well. As a result of this project we have many new tools for studying

  20. Control of DNA synthesis in inhibited and activated Agrostemma githago seeds

    Energy Technology Data Exchange (ETDEWEB)

    Hecker, M [Sektion Biologie, FG Algemeine Botanik und Pflanzenphysiologie, Universitaet Greifswald (German Democratic Republic)

    1975-01-01

    The relationships between DNA synthesis and germination capacity of Agrostemma seeds had been studied. Protein synthesis and RNA synthesis were activated at the very beginning of imbibition, whereas DNA synthesis started in the second part of the imbibition phase. Agrostemma seeds inhibited by higher temperature (30 degC), or aged seeds with a low germination capacity were characterized by a significantly reduced protein synthesis. DNA synthesis was also reduced. The inhibition of the protein synthesis of Agrostemma embryos fed with cycloheximide or actinomycin D caused a depression of DNA synthesis. The results indicated that the initiation of DNA synthesis of imbibing Agrostemma seeds depended on the synthesis of special proteins. Abscisic acid inhibited the growth as well as DNA synthesis of isolated Agrostemma embryos. Nitomycin inhibited germination and DNA synthesis to the same extent. Dormant seeds with an undiminished intensity of protein synthesis also showed a reduced incorporation of /sup 3/H-thymidine by DNA. It is suggested that DNA synthesis of imbibed seeds, which is a necessary prerequisite for the radicle protrusion, was involved in the mechanism of ripening of the Agrostemma seeds.

  1. Control of DNA synthesis in inhibited and activated Agrostemma githago seeds

    International Nuclear Information System (INIS)

    Hecker, M.

    1975-01-01

    The relationships between DNA synthesis and germination capacity of Agrostemma seeds had been studied. Protein synthesis and RNA synthesis were activated at the very beginning of imbibition, whereas DNA synthesis started in the second part of the imbibition phase. Agrostemma seeds inhibited by higher temperature (30 degC), or aged seeds with a low germination capacity were characterized by a significantly reduced protein synthesis. DNA synthesis was also reduced. The inhibition of the protein synthesis of Agrostemma embryos fed with cycloheximide or actinomycin D caused a depression of DNA synthesis. The results indicated that the initiation of DNA synthesis of imbibing Agrostemma seeds depended on the synthesis of special proteins. Abscisic acid inhibited the growth as well as DNA synthesis of isolated Agrostemma embryos. Nitomycin inhibited germination and DNA synthesis to the same extent. Dormant seeds with an undiminished intensity of protein synthesis also showed a reduced incorporation of 3 H-thymidine by DNA. It is suggested that DNA synthesis of imbibed seeds, which is a necessary prerequisite for the radicle protrusion, was involved in the mechanism of ripening of the Agrostemma seeds. (author)

  2. The role of the persistent fruit wall in seed water regulation in Raphanus raphanistrum (Brassicaceae).

    Science.gov (United States)

    Cousens, Roger D; Young, Kenneth R; Tadayyon, Ali

    2010-01-01

    Dry fruits remain around the seeds at dispersal in a number of species, especially the Brassicaceae. Explanations for this vary, but usually involve mechanisms of innate dormancy. We speculate that, instead, a persistent fruit may give additional protection through control of dehydration, to species growing in arid or Mediterranean environments where water is sporadic. X-rays and weight measurements were used to determine the extent to which Raphanus raphanistrum seeds within mature fruits imbibe water, and germination tests determined the roles of the fruit and seed coat in seed dormancy. Rates of water uptake and desiccation, and seedling emergence were compared with and without the fruit. Finally, germinability of seeds extracted from fruits was determined after various periods of moist conditions followed by a range of dry conditions. Most seeds rapidly take up water within the fruit, but they do not fully imbibe when compared with naked seeds. The seed coat is more important than the dry fruit wall in maintaining seed dormancy. The presence of a dry fruit slows emergence from the soil by up to 6-8 weeks. The fruit slows the rate of desiccation of the seed to a limited extent. The presence of the fruit for a few days during imbibition somehow primes more seeds to germinate than if the fruit is absent; longer moist periods within the pod appear to induce dormancy. The fruit certainly modifies the seed environment as external conditions change between wet and dry, but not to a great extent. The major role seems to be: (a) the physical restriction of imbibition and germination; and (b) the release and then re-imposition of dormancy within the seed. The ecological significance of the results requires more research under field conditions.

  3. Imaging of forced-imbibition in carbonate rocks using synchrotron X-ray micro-tomography

    Science.gov (United States)

    Singh, K.; Menke, H. P.; Andrew, M. G.; Lin, Q.; Saif, T.; Al-Khulaifi, Y.; Reynolds, C. A.; Bijeljic, B.; Rau, C.; Blunt, M. J.

    2016-12-01

    We have investigated the pore-scale behavior of brine-oil systems and oil trapping during forced-imbibition in a water-wet carbonate rock in a capillary-dominated flow regime at reservoir pressure conditions. To capture the dynamics of the brine-oil front progression and snap-off process, real-time tomograms with a time resolution of 38 s (24 s for imaging and 14 s for recording the data) and a spatial resolution of 3.28 µm were acquired at Diamond Light Source (UK). The data were first analyzed at global scale (complete imaged rock) for overall front behavior. From the saturation profiles, we obtain the location of the tail of the desaturation front that progresses with a velocity of 13 µm/min. This velocity is smaller than average flow velocity 16.88 µm/min, which explains why it needs slightly more than 1 pore volume of brine injection to reach the residual saturation of oil in a water-wet rock. The data were further analyzed at local scale to investigate the pore-scale mechanisms of oil trapping during brine flooding. We isolated various trapping events which resulted in the creation of discrete oil ganglia occupying one to several pore bodies. We perform pore-scale curvature analysis of brine-oil interfaces to obtain local capillary pressure that will be related to the shape and the size of throats in which ganglia were trapped.

  4. Recovery by imbibition from the lower Tamaulipas reservoir section A, Tamaulipas-Constituciones field

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, O D; Teyssier S, J

    1967-08-01

    The Tamaulipas-Constituciones Field is situated about 27 km from the city and port of Tampico, Mex., and is a part of the N. district, of the N. Development Zone of Petroleos Mexicanos. This article describes a method designed to calculate the recovery of oil by means of the application of a secondary recovery process based on the phenomenon of imbibition. The flow in the reservoir follows a system of fractures which are interconnected both in series, parallel, and randomly distributed. A more adequate method of development was determined than that which was enforced when the area wells started their initial production. Applying this method, 2 programs were developed; the first for an operation pressure of 125 kg per sq cm and the second for an operation pressure of 100 kg per cm. The production history is graphically represented. The characteristics of the reservoir are described, including the rock properties and the reservoir fluids. Complete information is furnished on the entire operation by means of tabular data. (15 refs.)

  5. Ethylene synthesis in lettuce seeds: its physiological significance.

    Science.gov (United States)

    Burdett, A N

    1972-12-01

    The germination and pregermination ethylene production of Grand Rapids lettuce seeds (Lactuca sativa L.) incubated at 20 C after a red light treatment are inhibited if the seeds are first imbibed at 30 C for 36 hours. In this study, low concentrations of ethylene were found to enhance the germination of seeds pretreated at 30 C more than that of untreated controls. In the presence of high concentrations of ethylene, pretreated seeds and controls germinated at a similar rate. These results are consistent with the view that a prolonged imbibition at 30 C inhibits germination at a lower temperature through its effect on the ethylene production of the seeds. As a further test of the hypothesis, estimates were made of the pregermination ethylene content of untreated seeds and pretreated seeds incubated in the presence of sufficient ethylene to make them germinate as rapidly as untreated seeds. The values obtained were 0.65 and 0.74 nanoliter of ethylene per gram (dry weight) of seeds, respectively.

  6. The oxygen requirement of germinating flax seeds

    Science.gov (United States)

    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).

  7. Physiological, cellular and molecular aspects of the desiccation tolerance in Anadenanthera colubrina seeds during germination

    Directory of Open Access Journals (Sweden)

    L. E. Castro

    2017-05-01

    Full Text Available Abstract During germination, orthodox seeds become gradually intolerant to desiccation, and for this reason, they are a good model for recalcitrance studies. In the present work, physiological, biochemical, and ultrastructural aspects of the desiccation tolerance were characterized during the germination process of Anadenanthera colubrina seeds. The seeds were imbibed during zero (control, 2, 8, 12 (no germinated seeds, and 18 hours (germinated seeds with 1 mm protruded radicle; then they were dried for 72 hours, rehydrated and evaluated for survivorship. Along the imbibition, cytometric and ultrastructural analysis were performed, besides the extraction of the heat-stable proteins. Posteriorly to imbibition and drying, the evaluation of ultrastructural damages was performed. Desiccation tolerance was fully lost after root protrusion. There was no increase in 4C DNA content after the loss of desiccation tolerance. Ultrastructural characteristics of cells from 1mm roots resembled those found in the recalcitrant seeds, in both hydrated and dehydrated states. The loss of desiccation tolerance coincided with the reduction of heat-stable proteins.

  8. Role of thioproline on seed germination: interaction ROS-ABA and effects on antioxidative metabolism.

    Science.gov (United States)

    Barba-Espin, Gregorio; Nicolas, Eduardo; Almansa, Maria Soledad; Cantero-Navarro, Elena; Albacete, Alfonso; Hernández, José Antonio; Díaz-Vivancos, Pedro

    2012-10-01

    In this work we investigate the effect of the imbibition of pea seeds with different thioproline (TP) concentrations on the germination percentage and the early growth of the seedlings. The interaction between TP and hydrogen peroxide (H₂O₂) treatments is also analysed in order to test if any synergy in germination and growth occurs. Although the imbibition of pea seeds in the presence of TP did not significantly improve the germination percentage, TP and/or H₂O₂ pre-treatments increased seedlings growth. This increase in seedling growth was reduced by abscisic acid (ABA) addition. Imbibition of pea seeds in the presence of ABA also reduced the endogenous H₂O₂ contents of pea seedlings in control and TP-treated seeds. The incubation of pea seeds with TP and/or H₂O₂ in presence or absence of ABA decreased the activity of H₂O₂-scavenging enzymes. The increase of the endogenous H₂O₂ contents observed in TP and/or H₂O₂ treatments in absence of ABA could be correlated with the decrease in these activities. Finally, the hormone profile of pea seedlings was investigated. The results show that the increase in seedling growth is correlated with a decrease in ABA in samples pre-treated with H₂O₂ and TP + H₂O₂. Nevertheless, no significant differences in endogenous ABA concentration were observed with the TP pre-treatment. This paper suggests a relationship between endogenous H₂O₂ contents and plant growth, so reinforcing the intricate crosstalk between reactive oxygen species (ROS) and plant hormones in seed germination signalling and early seedling development. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  9. (Heckel) seeds

    African Journals Online (AJOL)

    UTILISATEUR

    Garcinia kola seeds to six different hormonal pre-germination treatments. This consisted of ... Thus, seed dormancy in this case is not a coat- imposed .... development of the cultivation of the species. The cause .... Hormonal regulation of seed ...

  10. Drying and osmotic conditioning in Hancornia speciosa Gomes seeds

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    Full Text Available Hancornia speciosa is a native tree species of the Brazilian Cerrado whose seeds are desiccation sensitive. In this study, we aimed to evaluate drying and osmotic conditioning in H. speciosa seeds. We used fresh seeds with 48% moisture content, which were slowly dried until they attained contents of 20%, 15%, 10% and 5%. To evaluate osmotic conditioning, the seeds were imbibed in 12 mL osmotic solutions at 0.0; -0.2; -0.4 and -0.6 MPa for two days. After that, they were dehydrated until their original moisture content. The experiments were carried out in a completely randomized design with four repetitions with 50 seeds each. Reduction in moisture content from 20% to 5% decreased the physiological potential of seeds. H. speciosa seeds do not require osmotic priming with PEG solutions, because imbibition of seeds in osmotic solutions of up to -0.6 MPa results in reduction of germination rate and seedling length.

  11. The role of seed coat phenolics on water uptake and early protein synthesis during germination of dimorphic seeds of halopyrum mucronatum (L.) staph

    International Nuclear Information System (INIS)

    Siddiqui, Z. S.; Khan, M.A.

    2010-01-01

    Role of seed coat phenolics on water uptake and early protein synthesis of Halopyrum mucronatum dimorphic seeds during germination were tested. Scanning electron micrographs (SEM) showed seed texture with differential deposition of secondary metabolites in both morphs. Ability of both seed morphs to retain secondary deposition was dependent on exposure to either saline or non-saline conditions. More phenols leached from the brown seed during the initial hours of soaking when compared to black seeds. Water uptake pattern was slightly different in both seed type particularly during initial hours when imbibition in black seeds showed little water uptake while in brown seeds absorption was quick in the first hour under both saline and non saline condition. Change in total protein was somewhat similar in both seeds morphs showing early increase (4 and 8 h), reaching to the maximum (12 h) and decreasing (24 and 48 h) afterward. The results are discussed in relation to seed coat phenolics, water uptake and early protein synthesis during germination. (author)

  12. Physiological characteristics and related gene expression of after-ripening on seed dormancy release in rice.

    Science.gov (United States)

    Du, W; Cheng, J; Cheng, Y; Wang, L; He, Y; Wang, Z; Zhang, H

    2015-11-01

    After-ripening is a common method used for dormancy release in rice. In this study, the rice variety Jiucaiqing (Oryza sativa L. subsp. japonica) was used to determine dormancy release following different after-ripening times (1, 2 and 3 months). Germination speed, germination percentage and seedling emergence increased with after-ripening; more than 95% germination and 85% seedling emergence were observed following 1 month of after-ripening within 10 days of imbibition, compared with rice dormancy release. Dormancy release by after-ripening is mainly correlated with a rapid decline in ABA content and increase in IAA content during imbibition. Subsequently, GA(1)/ABA, GA(7)/ABA, GA(12)/ABA, GA(20)/ABA and IAA/ABA ratios significantly increased, while GA(3)/ABA, GA(4)/ABA and GAs/IAA ratio significantly decreased in imbibed seeds following 3 months of after-ripening, thereby altering α-amylase activity during seed germination. Peak α-amylase activity occurred at an earlier germination stage in after-ripened seeds than in freshly harvested seeds. Expression of ABA, GA and IAA metabolism genes and dormancy-related genes was regulated by after-ripening time upon imbibition. Expression of OsCYP707A5, OsGA2ox1, OsGA2ox2, OsGA2ox3, OsILR1, OsGH3-2, qLTG3-1 and OsVP1 increased, while expression of Sdr4 decreased in imbibed seeds following 3 months of after-ripening. Dormancy release through after-ripening might be involved in weakening tissues covering the embryo via qLTG3-1 and decreased ABA signalling and sensitivity via Sdr4 and OsVP1. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Enzyme activity and reserve mobilization during Macaw palm ( Acrocomia aculeata seed germination

    Directory of Open Access Journals (Sweden)

    Elisa Monteze Bicalho

    2016-01-01

    Full Text Available ABSTRACT Reserve mobilization in seeds occurs after visible germination, which is marked by the protrusion of the radicle or cotyledonary petiole, as in species of Arecaceae. Acrocomia aculeata (macaw palm, usually produces hard seeds whose endosperm has mannan-rich cell walls. We investigated the composition of storage compounds in macaw palm seed and the roles of two enzymes (endo-β-mannanase, α-galactosidase during and after germination. The seeds were firstly submitted to pre-established protocol to overcome dormancy and promote germination. Enzyme activity in both embryo and endosperm were assayed from the initiation of germinative activities until leaf sheath appearance, and the status of seed structures and reserve compounds were evaluated. Protein content of the embryo decreased with the initiation of imbibition while the lipid content began decreasing six days after removal of the operculum. Increases in enzyme activity and starch content were both observed after visible germination. We suggest that endo-β-mannanase and α-galactosidase become active immediately at germination, facilitating haustorium expansion and providing carbohydrates for initial seedling development. Protein is the first storage compound mobilized during early imbibition, and the observed increase in the starch content of the haustorium was related to lipid degradation in that organ and mannan degradation in the adjacent endosperm.

  14. The influence of temperature in a capillary imbibition salt weathering simulation test on Mokattam limestone

    Directory of Open Access Journals (Sweden)

    Aly, N.

    2015-03-01

    Full Text Available Limestone is one of the most frequent building stones used in monuments in Egypt from ancient Egyptian times and salt weathering is one of the main threats to these monuments. During this work, cylindrical limestone samples (2 cm diameter and approx. 4 cm length from Mokattam group, one of the most frequent materials in historic Cairo, were subjected, in a purpose-made simulation chamber, to laboratory salt weathering tests with a 10% weight NaCl solution at different temperatures (20, 30, 40 °C. During each test, temperature was kept constant and salt solutions flowed continuously imbibing samples by capillary rise resembling the way they get into building stone in many real cases. Air temperature, relative humidity inside the simulation chamber and also samples weight were digitally monitored and recorded. Results show the influence of temperature and the ratio between imbibitions and evaporation on the dynamics of salt crystallization in the samples.Los monumentos egipcios se construyeron frecuentemente con caliza desde la antigüedad y uno de sus principales agentes de deterioro son las sales. Por ejemplo, en la zona histórica de El Cairo son frecuentes las calizas del grupo Mokattam. Cilindros (2 cm de diámetro y aproximadamente 4 cm de altura de esta caliza se sometieron a ensayos de deterioro por sales en una cámara experimental específicamente diseñada. Se utilizó una solución salina (10% en peso de NaCl a diferentes temperaturas (20 °C, 30 °C, 40 °C que se mantuvieron constantes en cada ensayo. La solución fluía constantemente embebiendo las muestras por capilaridad, simulando lo que ocurre en casos reales. La temperatura del aire, humedad relativa en la cámara y peso de las muestras se monitorizaron con sensores digitales. Los resultados muestran la influencia de la temperatura y del balance entre imbibición y evaporación en la dinámica de la cristalización de sales en las muestras.

  15. Osmoconditioning prevents the onset of microtubular cytoskeleton and activation of cell cycle and is detrimental for germination of Jatropha curcas L. seeds.

    Science.gov (United States)

    de Brito, C D; Loureiro, M B; Ribeiro, P R; Vasconcelos, P C T; Fernandez, L G; de Castro, R D

    2016-11-01

    Jatropha curcas is an oilseed crop renowned for its tolerance to a diverse range of environmental stresses. In Brazil, this species is grown in semiarid regions where crop establishment requires a better understanding of the mechanisms underlying appropriate seed, seedling and plant behaviour under water restriction conditions. In this context, the objective of this study was to investigate the physiological and cytological profiles of J. curcas seeds in response to imbibition in water (control) and in polyethylene glycol solution (osmoticum). Seed germinability and reactivation of cell cycle events were assessed by means of different germination parameters and immunohistochemical detection of tubulin and microtubules, i.e. tubulin accumulation and microtubular cytoskeleton configurations in water imbibed seeds (control) and in seeds imbibed in the osmoticum. Immunohistochemical analysis revealed increasing accumulation of tubulin and appearance of microtubular cytoskeleton in seed embryo radicles imbibed in water from 48 h onwards. Mitotic microtubules were only visible in seeds imbibed in water, after radicle protrusion, as an indication of cell cycle reactivation and cell proliferation, with subsequent root development. Imbibition in osmoticum prevented accumulation of microtubules, i.e. activation of cell cycle, therefore germination could not be resumed. Osmoconditioned seeds were able to survive re-drying and could resume germination after re-imbibition in water, however, with lower germination performance, possibly due to acquisition of secondary dormancy. This study provides important insights into understanding of the physiological aspects of J. curcas seed germination in response to water restriction conditions. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery from Fractured Reservoirs by Spontaneous Imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Zhengxin Tong; Evren Unsal; Siluni Wickramathilaka; Shaochang Wo; Peigui Yin

    2008-06-30

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the non-wetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed

  17. FUNDAMENTALS OF RESERVOIR SURFACE ENERGY AS RELATED TO SURFACE PROPERTIES, WETTABILITY, CAPILLARY ACTION, AND OIL RECOVERY FROM FRACTURED RESERVOIRS BY SPONTANEOUS IMBIBITION

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow

    2004-05-01

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the nonwetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed

  18. FUNDAMENTALS OF RESERVOIR SURFACE ENERGY AS RELATED TO SURFACE PROPERTIES, WETTABILITY, CAPILLARY ACTION, AND OIL RECOVERY FROM FRACTURED RESERVOIRS BY SPONTANEOUS IMBIBITION

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow

    2004-07-01

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the nonwetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed

  19. Roles of gibberellins and abscisic acid in regulating germination of Suaeda salsa dimorphic seeds under salt stress

    Directory of Open Access Journals (Sweden)

    Weiqiang eLi

    2016-01-01

    Full Text Available Seed heteromorphism observed in many halophytes is an adaptive phenomenon toward high salinity. However, the relationship between heteromorphic seed germination and germination-related hormones under salt stress remains elusive. To gain an insight into this relationship, the roles of gibberellins (GAs and abscisic acid (ABA in regulating germination of Suaeda salsa dimorphic brown and black seeds under salinity were elucidated by studying the kinetics of the two hormones during germination of the two seed types with or without salinity treatment. Morphological analysis suggested that brown and black are in different development stage. The content of ABA was higher in dry brown than in black seeds, which gradually decreased after imbibition in water and salt solutions. Salt stress induced ABA accumulation in both germinating seed types, with higher induction effect on black than brown seeds. Black seeds showed lower germination percentage than brown seeds under both water and salt stress, which might be attributed to their higher ABA sensitivity rather than the difference in ABA content between black and brown seeds. Bioactive GA4 and its biosynthetic precursors showed higher levels in brown than in black seeds, whereas deactivated GAs showed higher content in black than brown seeds in dry or in germinating water or salt solutions. High salinity inhibited seed germination through decreasing the levels of GA4 in both seeds, and the inhibited effect of salt stress on GA4 level of black seeds was more profound than that of brown seeds. Taken together higher GA4 content, and lower ABA sensitivity contributed to the higher germination percentage of brown seeds than black seeds in water and salinity; increased ABA content and sensitivity, and decreased GA4 content by salinity were more profound in black than brown seeds, which contributed to lower germination of black seeds than brown seeds in salinity. The differential regulation of ABA and GA

  20. Approximating the imbibition and absorption behavior of a distribution of matrix blocks by an equivalent spherical block

    International Nuclear Information System (INIS)

    Zimmerman, R.W.; Bodvarsson, G.S.

    1994-03-01

    A theoretical study is presented of the effect of matrix block shape and matrix block size distribution on liquid imbibition and solute absorption in a fractured rock mass. It is shown that the behavior of an individual irregularly-shaped matrix block can be modeled with reasonable accuracy by using the results for a spherical matrix block, if one uses an effective radius a = 3V/A, where V is the volume of the block and A is its surface area. In the early-time regime of matrix imbibition, it is shown that a collection of blocks of different sizes can be modeled by a single equivalent block, with an equivalent radius of -1 > -1 , where the average is taken on a volumetrically-weighted basis. In an intermediate time regime, it is shown for the case where the radii are normally distributed that the equivalent radius is reasonably well approximated by the mean radius . In the long-time limit, where no equivalent radius can be rigorously defined, an asymptotic expression is derived for the cumulative diffusion as a function of the mean and the standard deviation of the radius distribution function

  1. Freezing tolerance of conifer seeds and germinants.

    Science.gov (United States)

    Hawkins, B J; Guest, H J; Kolotelo, D

    2003-12-01

    Survival after freezing was measured for seeds and germinants of four seedlots each of interior spruce (Picea glauca x engelmannii complex), lodgepole pine (Pinus contorta Dougl. ex Loud.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western red cedar (Thuja plicata Donn ex D. Donn). Effects of eight seed treatments on post-freezing survival of seeds and germinants were tested: dry, imbibed and stratified seed, and seed placed in a growth chamber for 2, 5, 10, 15, 20 or 30 days in a 16-h photoperiod and a 22/17 degrees C thermoperiod. Survival was related to the water content of seeds and germinants, germination rate and seedlot origin. After freezing for 3 h at -196 degrees C, dry seed of most seedlots of interior spruce, Douglas-fir and western red cedar had 84-96% germination, whereas lodgepole pine seedlots had 53-82% germination. Freezing tolerance declined significantly after imbibition in lodgepole pine, Douglas-fir and interior spruce seed (western red cedar was not tested), and mean LT50 of imbibed seed of these species was -30, -24.5 and -20 degrees C, respectively. Freezing tolerance continued to decline to a minimum LT50 of -4 to -7 degrees C after 10 days in a growth chamber for interior spruce, Douglas-fir and lodgepole pine, or after 15 days for western red cedar. Minimum freezing tolerance was reached at the stage of rapid hypocotyl elongation. In all species, a slight increase in freezing tolerance of germinants was observed once cotyledons emerged from the seed coat. The decrease in freezing tolerance during the transition from dry to germinating seed correlated with increases in seed water content. Changes in freezing tolerance between 10 and 30 days in the growth chamber were not correlated with seedling water content. Within a species, seedlots differed significantly in freezing tolerance after 2 or 5 days in the growth chamber. Because all seedlots of interior spruce and lodgepole pine germinated quickly, there was no correlation

  2. Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.

    Science.gov (United States)

    Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-04-01

    Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (Pseeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. © 2015 American Society of Plant Biologists. All Rights Reserved.

  3. Relationship between seed moisture content and acquisition of impermeability in Nelumbo nucifera (Nelumbonaceae

    Directory of Open Access Journals (Sweden)

    Ganesh K. Jaganathan

    Full Text Available ABSTRACT Seeds of Nelumbo nucifera do not imbibe water, and thus have physical dormancy (PY. However, a proportion of seeds are permeable to water, and so we hypothesized that variation in moisture content is a reason for the development of both permeable and impermeable seeds. The permeable proportion of seeds present in a lot collected from Suzhou, China, was separated using an imbibition test. The permeable proportion had an average moisture content of 15.6 %, compared with 8.5 % for impermeable seeds. Drying permeable seeds above silica gel to 10 % and 8 % f. wb., resulted in 77 and 100 % impermeable seeds, respectively, compared with no impermeable seeds at 15 % moisture content. Dried to 10 % moisture content, and incubated above water in an airtight container, 46 % of the seeds reverse impermeability. Permeable seeds with 15 % moisture content maintained above LiCl2 (RH=70 % did not develop impermeability after three months of storage. The seeds dried to 6 % moisture content and stored above water in an airtight container showed no increase in moisture. Based on these results, we conclude that there is a strong relationship between moisture content and the onset of impermeability in this species.

  4. Fatty acids and physiological quality of tomatillo (Physalis philadelphica Lam. seed during natural ageing

    Directory of Open Access Journals (Sweden)

    Juan M Pichardo-González

    2014-12-01

    Full Text Available In México, 44 thousand hectares are planted with tomatillo or husk tomato (Physalis philadelphica Lam., which occupies fourth place among the country's vegetable species. However, research on this species is scarce, especially that related to the process of seed deterioration. We studied the effects of deterioration in tomatillo seed, var. CHF1-Chapingo, stored from 2-mo up to 7 yr with no climate control, 18.2 ± 5 °C and 41 ± 10% relative humidity, on physiological and biochemical variables during germination. It was found that germination, vigor, and respiratory activity decrease significantly from the first year of storage; thus, after 7 yr, germination and vigor decreased 99%, and respiratory activity of seed after 48 h imbibition decreased 78%. Linoleic acid (unsaturated content correlated positively with germination (R = 0.78** and with speed of radicle emergence (R = 0.79**. Germination correlated with speed of radicle emergence (R = 0.99** and with respiratory activity after 48 h of imbibition (R = 0.79**. Both respiratory activity and fatty acid content are involved in natural deterioration of tomatillo seed.

  5. Proteomic Analysis of Lettuce Seed Germination and Thermoinhibition by Sampling of Individual Seeds at Germination and Removal of Storage Proteins by Polyethylene Glycol Fractionation1

    Science.gov (United States)

    Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Germination and thermoinhibition in lettuce (Lactuca sativa ‘Jianyexianfeng No. 1’) seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. PMID:25736209

  6. Mannans and endo-β-mannanase transcripts are located in different seed compartments during Brassicaceae germination.

    Science.gov (United States)

    Carrillo-Barral, Néstor; Matilla, Angel J; Rodríguez-Gacio, María Del Carmen; Iglesias-Fernández, Raquel

    2018-03-01

    Mannans but not endo-β-mannanases are mainly found in the mucilage layer of two Brassicaceae seeds. Nonetheless, mannanase mobilization from inner to outer seed layers cannot be ruled out. The contribution of endo-β-mannanase (MAN) genes to the germination of the wild-type Sisymbrium officinale and cultivated Brassica rapa (Brassicaceae) species has been explored. In both species, mannans have been localized to the imbibed external seed coat layer (mucilage) by fluorescence immunolocalization and MAN enzymatic activity increases in seeds as imbibition progresses, reaching a peak before 100% germination is achieved. The MAN gene families have been annotated and the expression of their members analyzed in vegetative and reproductive organs. In S. officinale and B. rapa, MAN2, MAN5, MAN6, and MAN7 transcripts accumulate upon seed imbibition. SoMAN7 is the most expressed MAN gene in S. officinale germinating seeds, as occurs with its ortholog in Arabidopsis thaliana, but in B. rapa, the most abundant transcripts are BrMAN2 and BrMAN5. These genes (MAN2, MAN5, MAN6, and MAN7) are localized, by mRNA in situ hybridization, to the micropylar at the endosperm layer and to the radicle in S. officinale, but in B. rapa, these mRNAs are faintly found to the micropylar living seed coat layer and are mainly present at the radicle tip and the vascular bundles. If the domestication process undergone by B. rapa is responsible for these different MAN expression patterns, upon germination remains to be elucidated. Since mannans and MAN genes are not spatially distributed in the same seed tissues, a movement of MAN enzymes that are synthesized with typical signal peptides from the embryo tissues to the mucilage layer (via apoplastic space) is necessary for the mannans to be hydrolyzed.

  7. Antagonism between abscisic acid and gibberellins is partially mediated by ascorbic acid during seed germination in rice.

    Science.gov (United States)

    Ye, Nenghui; Zhang, Jianhua

    2012-05-01

    The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. In the associated study, we investigated the relationship among ABA, reactive oxygen species (ROS), ascorbic acid (ASC) and GA during rice seed germination. ROS production is reduced by ABA, which hence results in decreasing ASC accumulation during imbibition. GA accumulation was also suppressed by a reduced ROS and ASC level, whereas application of exogenous ASC can partially rescue seed germination from ABA treatment. Further results show that production of ASC, which acts as a substrate in GA biosynthesis, was significantly inhibited by lycorine which thus suppressed the accumulation of GA. Consequently, expression of GA biosynthesis genes was suppressed by the low levels of ROS and ASC in ABA-treated seeds. These studies reveal a new role for ASC in mediating the antagonism between ABA and GA during seed germination in rice.

  8. Antagonistic effects of high and low temperature pretreatments on the germination and pregermination ethylene synthesis of lettuce seeds.

    Science.gov (United States)

    Burdett, A N

    1972-08-01

    Red light-induced germination of Grand Rapids lettuce seeds (Lactuca sativa L.) incubated at 20 C was inhibited if the seeds were first imbibed at 30 C for 36 hours. This effect was counteracted by exogenous ethylene and associated with a reduction in the rate at which the seeds produced ethylene throughout the pregermination period. A chilling treatment reversed the effect of a prior imbibition at 30 C on both germination and ethylene production. The possibility that the pretreatments influence germination through their effects on ethylene production is discussed.Other evidence presented indicates that the inability of seeds to germinate at supraoptimal temperature is not due either to a rapid loss of far red-absorbing phytochrome or to an inadequate capacity for ethylene synthesis. It was also shown that a chilling treatment potentiated germination at high temperature without affecting the ethylene synthetic capacity of the seeds.

  9. Interaction of cold radiofrequency plasma with seeds of beans (Phaseolus vulgaris)

    Science.gov (United States)

    Bormashenko, Edward; Shapira, Yekaterina; Grynyov, Roman; Whyman, Gene; Bormashenko, Yelena; Drori, Elyashiv

    2015-01-01

    The impact of cold radiofrequency air plasma on the wetting properties and water imbibition of beans (Phaseolus vulgaris) was studied. The influence of plasma on wetting of a cotyledon and seed coat (testa) was elucidated. It was established that cold plasma treatment leads to hydrophilization of the cotyledon and tissues constituting the testa when they are separately exposed to plasma. By contrast, when the entire bean is exposed to plasma treatment, only the external surface of the bean is hydrophilized by the cold plasma. Water imbibition by plasma-treated beans was studied. Plasma treatment markedly accelerates the water absorption. The crucial role of a micropyle in the process of water imbibition was established. It was established that the final percentage of germination was almost the same in the cases of plasma-treated, untreated, and vacuum-pumped samples. However, the speed of germination was markedly higher for the plasma-treated samples. The influence of the vacuum pumping involved in the cold plasma treatment on the germination was also clarified. PMID:25948708

  10. Dynamic Proteomics Emphasizes the Importance of Selective mRNA Translation and Protein Turnover during Arabidopsis Seed Germination*

    Science.gov (United States)

    Galland, Marc; Huguet, Romain; Arc, Erwann; Cueff, Gwendal; Job, Dominique; Rajjou, Loïc

    2014-01-01

    During seed germination, the transition from a quiescent metabolic state in a dry mature seed to a proliferative metabolic state in a vigorous seedling is crucial for plant propagation as well as for optimizing crop yield. This work provides a detailed description of the dynamics of protein synthesis during the time course of germination, demonstrating that mRNA translation is both sequential and selective during this process. The complete inhibition of the germination process in the presence of the translation inhibitor cycloheximide established that mRNA translation is critical for Arabidopsis seed germination. However, the dynamics of protein turnover and the selectivity of protein synthesis (mRNA translation) during Arabidopsis seed germination have not been addressed yet. Based on our detailed knowledge of the Arabidopsis seed proteome, we have deepened our understanding of seed mRNA translation during germination by combining two-dimensional gel-based proteomics with dynamic radiolabeled proteomics using a radiolabeled amino acid precursor, namely [35S]-methionine, in order to highlight de novo protein synthesis, stability, and turnover. Our data confirm that during early imbibition, the Arabidopsis translatome keeps reflecting an embryonic maturation program until a certain developmental checkpoint. Furthermore, by dividing the seed germination time lapse into discrete time windows, we highlight precise and specific patterns of protein synthesis. These data refine and deepen our knowledge of the three classical phases of seed germination based on seed water uptake during imbibition and reveal that selective mRNA translation is a key feature of seed germination. Beyond the quantitative control of translational activity, both the selectivity of mRNA translation and protein turnover appear as specific regulatory systems, critical for timing the molecular events leading to successful germination and seedling establishment. PMID:24198433

  11. Modelling critical NDVI curves in perennial ryegrass

    DEFF Research Database (Denmark)

    Gislum, R; Boelt, B

    2010-01-01

      The use of optical sensors to measure canopy reflectance and calculate crop index as e.g. normalized difference vegetation index (NDVI) is widely used in agricultural crops, but has so far not been implemented in herbage seed production. The present study has the purpose to develop a critical...... NDVI curve where the critical NDVI, defined as the minimum NDVI obtained to achieve a high seed yield, will be modelled during the growing season. NDVI measurements were made at different growing degree days (GDD) in a three year field experiment where different N application rates were applied....... There was a clear maximum in the correlation coefficient between seed yield and NDVI in the period from approximately 700 to 900 GDD. At this time there was an exponential relationship between NDVI and seed yield where highest seed yield were at NDVI ~0.9. Theoretically the farmers should aim for an NDVI of 0...

  12. Magnetic-seeding filtration

    International Nuclear Information System (INIS)

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab

  13. Seed quality in informal seed systems

    NARCIS (Netherlands)

    Biemond, P.C.

    2013-01-01

    Keywords: informal seed systems, seed recycling, seed quality, germination, seed pathology, seed health, seed-borne diseases, mycotoxigenic fungi, Fusarium verticillioides, mycotoxins, Vigna unguiculata, Zea mays, Nigeria.

    Seed is a crucial input for agricultural production.

  14. Cell signaling mechanisms and metabolic regulation of germination and dormancy in barley seeds

    Directory of Open Access Journals (Sweden)

    Zhenguo Ma

    2017-12-01

    Full Text Available During germination of barley (Hordeum vulgare L. seeds, important morphological and physiological changes take place, including development of organs and tissues and activation of metabolic pathways. Germination and dormancy of seeds are regulated by abscisic acid, gibberellins, reactive oxygen species (ROS, reactive nitrogen species (RNS and several other factors. Activities of ascorbate–glutathione cycle enzymes, responsible for scavenging ROS, strongly increase. Catalase and superoxide dismutase activities, also scavenging ROS, decrease at the onset of seed germination and then increase. With the increase in aerobic metabolism after radicle protrusion, the activities of the fermentation enzymes lactate and alcohol dehydrogenase decline rapidly. The RNS-scavenging activity of S-nitrosoglutathione reductase decreases in the course of seed germination, in concert with elevation of nitric oxide production and protein nitrosylation. This activity supports the role of RNS in regulating seed germination. Transcription of various genes at different phases of seed germination exhibits phase-specific changes. During imbibition, genes involved in cell wall metabolism are highly expressed; in the middle phase of seed germination before radicle protrusion, genes involved in amino acid synthesis, protein synthesis, and transport and nucleic acid synthesis are upregulated significantly, and after radicle protrusion, genes involved in photosynthetic metabolism are induced. In summary, signal transduction and metabolic regulation of seed germination involve diverse reactions and complex regulation at different levels of metabolic organization. Keywords: Seed germination, Reactive oxygen species, Reactive nitrogen species, Signal transduction, Gene expression

  15. Seed Hydropriming and Smoke Water Significantly Improve Low-Temperature Germination of Lupinus angustifolius L.

    Directory of Open Access Journals (Sweden)

    Agnieszka Płażek

    2018-03-01

    Full Text Available Seed imbibition under cold temperature is dangerous when dry seeds have relatively low water content. The aim of this study was to investigate germination of 20 lines/cultivars of narrow-leaf lupine at 7 °C (cold and 13 °C (control under the influence of smoke water and following seed hydropriming for 3 h at 20 °C. The efficacy of individual treatments was examined with regard to seed protection during low-temperature germination. Based on seed germination, vigour at cold was evaluated four days after sowing by means of hypocotyl length, the studied lines/cultivars were divided into three groups with low, high and very high germination rates. Germination vigour correlated with cell membrane permeability, dehydrogenase activity and abscisic acid (ABA content and was analysed in the seeds one day after sowing. Gibberellin content did not correlate with germination vigour. The seeds of weakly germinating lines/cultivars had the highest cell permeability and ABA content as well as the lowest amylolytic activity at both studied temperatures. Additionally, the vigour of weakly germinating seeds at 7 °C correlated with dehydrogenase activity. Three-hour hydropriming was the most effective for seed germination under cold due to reduced cell membrane permeability and ABA level. Stimulating effects of smoke water on germination under cold could be explained by enhanced dehydrogenase activity.

  16. Initial characterisation of low and high seed dormancy populations of Lolium rigidum produced by repeated selection.

    Science.gov (United States)

    Goggin, Danica E; Emery, R J Neil; Powles, Stephen B; Steadman, Kathryn J

    2010-10-15

    The physiological and biochemical bases of seed dormancy in Lolium rigidum (annual ryegrass) are largely unknown, and study of this process is complicated by the outcrossing nature of the species and the strong influence of environment on seed dormancy. In order to identify heritable biochemical factors contributing to seed dormancy in L. rigidum, seeds from a field-collected population were used to select sub-populations with consistently low or high seed dormancy over four generations. Low-dormancy seeds showed constitutive alpha-amylase activity prior to imbibition, higher concentrations of polyphenols and cis-zeatin, and lower abscisic acid and cis-zeatin riboside concentrations than high-dormancy seeds. Selection for high dormancy was associated with a reduction in response to dark-stratification for 21d at 20 degrees C (an effective means of releasing dormancy in the original, unselected population) over successive generations, but fluridone remained effective in breaking dormancy. Crossing of low- and high-dormancy populations indicated that dormancy level was not dependent upon the maternal genotype of the seed, and that the constitutive alpha-amylase activity and high seed anthocyanin concentrations characteristic of the low-dormancy populations were not correlated to high basal germination ability. Copyright (c) 2010 Elsevier GmbH. All rights reserved.

  17. Unraveling Key Metabolomic Alterations in Wheat Embryos Derived from Freshly Harvested and Water-Imbibed Seeds of Two Wheat Cultivars with Contrasting Dormancy Status

    Directory of Open Access Journals (Sweden)

    Aayudh Das

    2017-07-01

    Full Text Available Untimely rains in wheat fields during harvest season can cause pre-harvest sprouting (PHS, which deteriorates the yield and quality of wheat crop. Metabolic homeostasis of the embryo plays a role in seed dormancy, determining the status of the maturing grains either as dormant (PHS-tolerant or non-dormant (PHS-susceptible. Very little is known for direct measurements of global metabolites in embryonic tissues of dormant and non-dormant wheat seeds. In this study, physiologically matured and freshly harvested wheat seeds of PHS-tolerant (cv. Sukang, dormant and PHS-susceptible (cv. Baegjoong, non-dormant cultivars were water-imbibed, and the isolated embryos were subjected to high-throughput, global non-targeted metabolomic profiling. A careful comparison of identified metabolites between Sukang and Baegjoong embryos at 0 and 48 h after imbibition revealed that several key metabolic pathways [such as: lipids, fatty acids, oxalate, hormones, the raffinose family of oligosaccharides (RFOs, and amino acids] and phytochemicals were differentially regulated between dormant and non-dormant varieties. Most of the membrane lipids were highly reduced in Baegjoong compared to Sukang, which indicates that the cell membrane instability in response to imbibition could also be a key factor in non-dormant wheat varieties for their untimely germination. This study revealed that several key marker metabolites (e.g., RFOs: glucose, fructose, maltose, and verbascose, were highly expressed in Baegjoong after imbibition. Furthermore, the data showed that the key secondary metabolites and phytochemicals (vitexin, chrysoeriol, ferulate, salidroside and gentisic acid, with known antioxidant properties, were comparatively low at basal levels in PHS-susceptible, non-dormant cultivar, Baegjoong. In conclusion, the results of this investigation revealed that after imbibition the metabolic homeostasis of dormant wheat is significantly less affected compared to non

  18. NUTRIENT COMPOSITION OF NIGER SEED (GUIZOTIA ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    fiber. Niger oil has a fatty acid composition typical for seed oils of the .... system using external calibration curve after optimizing the parameters in to .... physical and chemical properties of the soil, application of natural (manure) and artificial.

  19. Capillary filling rules and displacement mechanisms for spontaneous imbibition of CO2 for carbon storage and EOR using micro-model experiments and pore scale simulation

    Science.gov (United States)

    Chapman, E.; Yang, J.; Crawshaw, J.; Boek, E. S.

    2012-04-01

    In the 1980s, Lenormand et al. carried out their pioneering work on displacement mechanisms of fluids in etched networks [1]. Here we further examine displacement mechanisms in relation to capillary filling rules for spontaneous imbibition. Understanding the role of spontaneous imbibition in fluid displacement is essential for refining pore network models. Generally, pore network models use simple capillary filling rules and here we examine the validity of these rules for spontaneous imbibition. Improvement of pore network models is vital for the process of 'up-scaling' to the field scale for both enhanced oil recovery (EOR) and carbon sequestration. In this work, we present our experimental microfluidic research into the displacement of both supercritical CO2/deionised water (DI) systems and analogous n-decane/air - where supercritical CO2 and n-decane are the respective wetting fluids - controlled by imbibition at the pore scale. We conducted our experiments in etched PMMA and silicon/glass micro-fluidic hydrophobic chips. We first investigate displacement in single etched pore junctions, followed by displacement in complex network designs representing actual rock thin sections, i.e. Berea sandstone and Sucrosic dolomite. The n-decane/air experiments were conducted under ambient conditions, whereas the supercritical CO2/DI water experiments were conducted under high temperature and pressure in order to replicate reservoir conditions. Fluid displacement in all experiments was captured via a high speed video microscope. The direction and type of displacement the imbibing fluid takes when it enters a junction is dependent on the number of possible channels in which the wetting fluid can imbibe, i.e. I1, I2 and I3 [1]. Depending on the experiment conducted, the micro-models were initially filled with either DI water or air before the wetting fluid was injected. We found that the imbibition of the wetting fluid through a single pore is primarily controlled by the

  20. Membrane damage and solute leakage from germinating pea seed under cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Rahoui, Sondes, E-mail: rahoui.sondes@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Chaoui, Abdelilah, E-mail: cabdelilah1@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); El Ferjani, Ezzeddine, E-mail: ezzferjani2002@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia)

    2010-06-15

    Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

  1. Membrane damage and solute leakage from germinating pea seed under cadmium stress

    International Nuclear Information System (INIS)

    Rahoui, Sondes; Chaoui, Abdelilah; El Ferjani, Ezzeddine

    2010-01-01

    Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

  2. seed oils

    African Journals Online (AJOL)

    Timothy Ademakinwa

    processes, production of biodiesel, as lubricant and in deep-frying purposes. They could ... for its juice, nectars and fruit while its seeds are ... Malaysia. The fine seed powder was stored in a plastic container inside a refrigerator at between 4 o.

  3. seed flour

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... and with a nice taste, used for cooking or as lamp oil. The fatty acid ... Pra seeds were obtained from a local market in Nakhon Si Thammarat. Page 2. Table 1. Proximate composition of pra seed flour. Constituent. Percentage ...

  4. Sugars and Desiccation Tolerance in Seeds 1

    Science.gov (United States)

    Koster, Karen L.; Leopold, A. Carl

    1988-01-01

    Soluble sugars have been shown to protect liposomes and lobster microsomes from desiccation damage, and a protective role has been proposed for them in several anhydrous systems. We have studied the relationship between soluble sugar content and the loss of desiccation tolerance in the axes of germinating soybean (Glycine max L. Merr. cv Williams), pea (Pisum sativum L. cv Alaska), and corn (Zea mays L. cv Merit) axes. The loss of desiccation tolerance during imbibition was monitored by following the ability of seeds to germinate after desiccation following various periods of preimbibition and by following the rates of electrolyte leakage from dried, then rehydrated axes. Finally, we analyzed the soluble sugar contents of the axes throughout the transition from desiccation tolerance to intolerance. These analyses show that sucrose and larger oligosaccharides were consistently present during the tolerant stage, and that desiccation tolerance disappeared as the oligosaccharides were lost. The results support the idea that sucrose may serve as the principal agent of desiccation tolerance in these seeds, with the larger oligosaccharides serving to keep the sucrose from crystallizing. PMID:16666392

  5. Robotic seeding

    DEFF Research Database (Denmark)

    Pedersen, Søren Marcus; Fountas, Spyros; Sørensen, Claus Aage Grøn

    2017-01-01

    Agricultural robotics has received attention for approximately 20 years, but today there are only a few examples of the application of robots in agricultural practice. The lack of uptake may be (at least partly) because in many cases there is either no compelling economic benefit......, or there is a benefit but it is not recognized. The aim of this chapter is to quantify the economic benefits from the application of agricultural robots under a specific condition where such a benefit is assumed to exist, namely the case of early seeding and re-seeding in sugar beet. With some predefined assumptions...... with regard to speed, capacity and seed mapping, we found that among these two technical systems both early seeding with a small robot and re-seeding using a robot for a smaller part of the field appear to be financially viable solutions in sugar beet production....

  6. Changes in endogenous abscisic acid levels during dormancy release and maintenance of mature seeds: studies with the Cape Verde Islands ecotype, the dormant model of Arabidopsis thaliana.

    Science.gov (United States)

    Ali-Rachedi, Sonia; Bouinot, Denise; Wagner, Marie-Hélène; Bonnet, Magda; Sotta, Bruno; Grappin, Philippe; Jullien, Marc

    2004-07-01

    Mature seeds of the Cape Verde Islands (Cvi) ecotype of Arabidopsis thaliana (L.) Heynh. show a very marked dormancy. Dormant (D) seeds completely fail to germinate in conditions that are favourable for germination whereas non-dormant (ND) seeds germinate easily. Cvi seed dormancy is alleviated by after-ripening, stratification, and also by nitrate or fluridone treatment. Addition of gibberellins to D seeds does not suppress dormancy efficiently, suggesting that gibberellins are not directly involved in the breaking of dormancy. Dormancy expression of Cvi seeds is strongly dependent on temperature: D seeds do not germinate at warm temperatures (20-27 degrees C) but do so easily at a low temperature (13 degrees C) or when a fluridone treatment is given to D seeds sown at high temperature. To investigate the role of abscisic acid (ABA) in dormancy release and maintenance, we measured the ABA content in both ND and D seeds imbibed using various dormancy-breaking conditions. It was found that dry D seeds contained higher amounts of ABA than dry ND after-ripened seeds. During early imbibition in standard conditions, there was a decrease in ABA content in both seeds, the rate of which was slower in D seeds. Three days after sowing, the ABA content in D seeds increased specifically and then remained at a high level. When imbibed with fluridone, nitrate or stratified, the ABA content of D seeds decreased and reached a level very near to that of ND seeds. In contrast, gibberellic acid (GA3) treatment caused a transient increase in ABA content. When D seeds were sown at low optimal temperature their ABA content also decreased to the level observed in ND seeds. The present study indicates that Cvi D and ND seeds can be easily distinguished by their ability to synthesize ABA following imbibition. Treatments used here to break dormancy reduced the ABA level in imbibed D seeds to the level observed in ND seeds, with the exception of GA3 treatment, which was active in promoting

  7. Exogenous melatonin improves corn (Zea mays L.) embryo proteome in seeds subjected to chilling stress.

    Science.gov (United States)

    Kołodziejczyk, Izabela; Dzitko, Katarzyna; Szewczyk, Rafał; Posmyk, Małgorzata M

    2016-04-01

    Melatonin (MEL; N-acetyl-5-methoxytryptamine) plays an important role in plant stress defense. Various plant species rich in this indoleamine have shown a higher capacity for stress tolerance. Moreover, it has great potential for plant biostimulation, is biodegradable and non-toxic for the environment. All this indicates that our concept of seed enrichment with exogenous MEL is justified. This work concerns the effects of corn (Zea mays L.) seed pre-sowing treatments supplemented with MEL. Non-treated seeds (nt), and those hydroprimed with water (H) or with MEL solutions 50 and 500 μM (HMel50, HMel500) were compared. Positive effects of seed priming are particularly apparent during germination under suboptimal conditions. The impact of MEL applied by priming on seed protein profiles during imbibition/germination at low temperature has not been investigated to date. In order to identify changes in the corn seed proteome after applying hydropriming techniques, purified protein extracts of chilling stressed seed embryos (14 days, 5°C) were separated by two-dimensional electrophoresis. Then proteome maps were graphically and statistically compared and selected protein spots were qualitatively analyzed using mass spectrometry techniques and identified. This study aimed to analyze the priming-induced changes in maize embryo proteome and at identifying priming-associated and MEL-associated proteins in maize seeds subjected to chilling. We attempt to explain how MEL expands plant capacity for stress tolerance. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Behavior of Jatropha curcas L. seeds under osmotic stress: germination and cell cycle activity

    Directory of Open Access Journals (Sweden)

    Cristiane Dantas de Brito

    2015-08-01

    Full Text Available Jatropha curcas is an oil-rich Euphorbiaceae seed species renowned for its apparent tolerance to environmental stresses. It is considered a promising source of renewable feedstock for biodiesel production in the Brazilian semiarid region where crop establishment requires a better understanding of the mechanisms leading to proper seed and plant behavior under water restrictive conditions. This study describes physiological and cytological profiles of J. curcas seeds imbibed in water restriction conditions by means of osmotic stress or osmoconditioning. Seeds were characterized by size, weight, moisture content and dry mass, germinability, and cell cycle activation by means of tubulin and microtubule cytoskeleton accumulation. Osmoconditioning at -0.8 MPa did not induce priming effects as it did not improve the physiological quality of the seed lots. Western blotting and immunocytochemical analysis revealed an increasing accumulation of tubulin and microtubule cytoskeleton in seeds imbibed in water for 48h onwards, culminating in the onset of mitotic configurations after germination. Only cortical microtubules were observed during seed osmoconditioning, whereas mitotic microtubules only occurred after re-imbibition of osmoconditioned seeds in water and subsequent germination.

  9. Seed regulations and local seed systems

    NARCIS (Netherlands)

    Louwaars, N.

    2000-01-01

    Seed regulations have been introduced in most countries based on the development of formal seed production. Concerns about seed quality and about the varietal identity of the seeds have commonly led to seed laws. However, formal regulations are often inappropriate for informal seed systems, which

  10. Small heat shock proteins can release light dependence of tobacco seed during germination.

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia; Hong, Choo Bong

    2015-03-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. © 2015 American Society of Plant Biologists. All Rights Reserved.

  11. Small Heat Shock Proteins Can Release Light Dependence of Tobacco Seed during Germination1[OPEN

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia

    2015-01-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. PMID:25604531

  12. Viability of Macrotyloma axillare cv. Guatá seeds under chemical scarification

    Directory of Open Access Journals (Sweden)

    Suleize Rocha Terra

    2012-12-01

    Full Text Available The use of the associacion of grasses and legumes results in a good forage yield as well as a good animal performance due to maintenance of adequate levels of crude protein (CP in the animal diet, both the direct effect of the ingestion of legumes, or even through indirect effect of the introduction of nitrogen by legumes in the pasture, thereby increasing the production of forage mass. However, the seeds of legumines have the so-called hardness seeds or dormant according to their coats impermeable to water. The hardness of the seed prevents the germination of the same since these seeds have a hard shell impervious to water and gas exchange, not allowing the imbibition of water by the seed, or embryo oxygenation. This dormancy may be broken by various known methods such as scarification, promoting cracks in the seed coat allowing the entry of water therein. In the case of Macrotyloma axillare exposure of seeds to scarification method has proven to be an efficient way to break dormancy and promoting seed germination. The aim of the present work was to evaluate the viability of seeds after suffering dormancy by immersion seeds in sulfuric acid. The experiment to break dormancy Macrotyloma axillares cv. Guatá was conducted in the laboratory of Plant Physiology at the Intituto de Zootecnia in Nova Odessa, São Paulo State, using the seeds that were stored in a cold room with temperatures between 10-12 ºC, relative humidity (RH 30-33% and no light. The treatments studied were: control, chemical scarification with sulfuric acid for 5, 10, 15, 20, 30 and 40 minutes. We used a completely randomized design with two replications, being 100 seeds each repetition. After treatment the seeds were under to tetrazolium test resulting in viable seeds and seed viability. So the result of the tetrazolium test was obtained by average percentage of viable seeds, found in the repeats tested, respecting the maximum tolerances set out in Brazilian Rules for Seed

  13. Lagrangian Curves on Spectral Curves of Monopoles

    International Nuclear Information System (INIS)

    Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.

    2010-01-01

    We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.

  14. A non-invasive and rapid seed vigor biosensor based on quantitative measurement of superoxide generated by aleurone cell in intact seeds.

    Science.gov (United States)

    Liu, Xuejun; Gao, Caiji; Xing, Da

    2009-02-15

    Superoxide generated during the early imbibition is an excellent marker for evaluating seed vigor. In this paper, a new principle biosensor for non-invasive detection of seed vigor based on quantitative measurement of superoxide via selective probe 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo [1,2alpha] pyrazin-3-one (MCLA)-mediated chemiluminescence (CL) was developed. The biosensor, which used a compact single-photon counting module (SPCM) to collect the CL signal, could evaluate seed vigor in vivo. Benefiting from the high CL efficiency of MCLA reacting with superoxide and high sensitivity of the SPCM technique, the trace superoxide generated by dry seeds under storage state can be detected to achieve rapid and non-invasive determination of the seed vigor. In comparison with the traditional methods for fast measuring seed vigor based on measurement of physiological and biochemical properties, our proposed technique has significant advantages such as low cost, simplicity, convenient operation and short time consuming. To demonstrate the utility of the system, it was applied to evaluate MCLA-mediated CL of three different plant species wheat (Ze Yu No. 2), maize (Tai Gu No. 1 and 2) and rice (Jing Dao No. 21) seeds with different degrees of aging. The experimental results suggested that there was an excellent positive correlation between the seed vigor assessment from quantitative TTC-test and the detection based on MCLA-mediated CL of superoxide measurement. The new principle of seed vigor measurement is a challenge and breakthrough to conventional method of seed vigor determination and may be a potential technique of the next generation seed vigor detection.

  15. Comparação de modelos matemáticos para descrição das curvas de dessorção de sementes de milho-doce Comparison of mathematical models for description of desorption curves of sweet corn seeds

    Directory of Open Access Journals (Sweden)

    Eduardo Fontes Araújo

    2001-07-01

    Full Text Available Este trabalho teve como objetivo determinar as curvas de dessorção das sementes de milho-doce (Zea mays L., cultivares Superdoce e Doce Cristal, e ajustar diferentes modelos matemáticos aos dados obtidos. As sementes das duas cultivares foram submetidas à dessorção em diversos níveis de temperatura (30, 40, 50 e 60°C, combinados com diferentes umidades relativas do ar (30, 40, 50 e 60%, até atingirem a umidade de equilíbrio. Os seguintes modelos matemáticos foram ajustados por análise de regressão: Henderson-Thompson, Chung-Pfost, Copace, Sigma-Copace, Sabbah e Smith. As sementes das duas cultivares apresentaram umidades de equilíbrio higroscópico semelhantes. Os valores da variância explicada e do desvio-padrão, bem como a distribuição dos resíduos, das duas cultivares, indicam que as equações de Chung-Pfost, Sabbah e Smith foram as que melhor se ajustaram aos dados experimentais, com pequena superioridade da primeira.This work had the goal to determine the desorption curves of seeds of sweet corn cultivars Superdoce and Doce Cristal, and to adjust mathematical models to obtained data. Corn seeds were submitted to desorption under different temperature conditions (30, 40, 50 and 60°C, associated with different relative humidity (30, 40, 50 and 60% until reaching the equilibrium humidity. The following models of regression analysis were adjusted to the experimental data: Henderson-Thompson, Chung-Pfost, Copace, Sigma-Copace, Sabbah and Smith. Seeds of both cultivars showed similar hygroscopic equilibrium. For both cultivars, the equations of Chung-Pfost, Sabbah and Smith, showed the best adjustments to the experimental data, with slight superiority of the first one.

  16. Morphology, ecophysiology and germination of seeds of the Neotropical tree Alibertia patinoi (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Diego Fernando Escobar Escobar

    2013-06-01

    Full Text Available Alibertia patinoi (Rubiaceae. 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.

  17. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions

    Science.gov (United States)

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-01-01

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis. PMID:26902640

  18. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions.

    Science.gov (United States)

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-02-23

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis.

  19. Osmotic Effect of Conditioning on Seeds of Tomato (Solanum Lycopersicum L. Santa Clara Variety

    Directory of Open Access Journals (Sweden)

    Brigitte Liliana Moreno Medina

    2013-12-01

    Full Text Available The tomato (Solanum lycopersicum L. is one of the most important vegetables in the world, taking into account its nutritional potential and high economic value. In this crop the quality of seed depends on various factors, one of which is its physiology, which is determined by a germination and viability test. Osmotic seed conditioning is reported to be a technique for improving the physiological quality through the uniformity of the germination percentage. For this reason, the objective of this research was to evaluate the osmotic conditioning on tomato seeds of the Santa Clara variety. Using treatments of four doses of potassium nitrate (0, 100, 200 and 400 mg L-1 , the seeds were imbibitioned for 24 hours in solution and then washed with distilled water. They were placed in petri dishes in random order with three replications for a total of 12 experimental units, consisting of 35 seeds. The method seeks to hydrate the seeds with a solution of given concentration and for a period of time, in order to activate the seed metabolism. The best result was obtained with the treatment of 200 mg L-1 of potassium nitrate, followed by 400 mg L-1 , represented by a lower TMG , lower and higher PG VMG.

  20. Cadmium and chromium effects on seed germination and root elongation in lettuce, spinach and Swiss chard

    Directory of Open Access Journals (Sweden)

    Oscar V Bautista

    2013-04-01

    Full Text Available The La Ramada district and the Bogota River are the principal water resources used for horticultural crop production on the Bogota Plateau, which contain channel pollutant materials, including heavy metals due to domestic and industrial activities on the Plateau. These materials have effects on crop production in this zone. The present research, under laboratory conditions, aimed to evaluate the effect of three concentrations (25, 35 and 50 µM L-1 of cadmium (Cd and chromium (Cr on imbibition, seed germination and root elongation in lettuce (Lactuca sativa var. Batavia, Swiss chard (Beta vulgaris var. cicla "White Ribbed", and spinach (Spinacia oleracea Hib. 424, three species widely cultivated on the Plateau. The three species used for evaluation showed a differential susceptibility response to Cd and Cr. In lettuce, fresh weight increase (imbibition was lower with all Cd concentrations at the last day of observation and at 25 µM L-1 of Cd in Swiss chard. Cadmium reduced seed germination by up to 46%, 97% and 8% in Swiss chard, lettuce and spinach, respectively. Also, root elongation decreased in Cd treatments by up to 57%, 89% and 56%, for Swiss chard, lettuce and spinach, respectively. Chromium, which showed fewer negative effects, decreased germination by up to 29% in Swiss chard, 6% in lettuce and 34% in spinach, as compared to the control

  1. The role of the Arabidopsis FUSCA3 transcription factor during inhibition of seed germination at high temperature.

    Science.gov (United States)

    Chiu, Rex S; Nahal, Hardeep; Provart, Nicholas J; Gazzarrini, Sonia

    2012-01-27

    Imbibed seeds integrate environmental and endogenous signals to break dormancy and initiate growth under optimal conditions. Seed maturation plays an important role in determining the survival of germinating seeds, for example one of the roles of dormancy is to stagger germination to prevent mass growth under suboptimal conditions. The B3-domain transcription factor FUSCA3 (FUS3) is a master regulator of seed development and an important node in hormonal interaction networks in Arabidopsis thaliana. Its function has been mainly characterized during embryonic development, where FUS3 is highly expressed to promote seed maturation and dormancy by regulating ABA/GA levels. In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP) during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes. In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying germination at supraoptimal temperature. Physiologically, this is

  2. The role of the Arabidopsis FUSCA3 transcription factor during inhibition of seed germination at high temperature

    Directory of Open Access Journals (Sweden)

    Chiu Rex S

    2012-01-01

    Full Text Available Abstract Background Imbibed seeds integrate environmental and endogenous signals to break dormancy and initiate growth under optimal conditions. Seed maturation plays an important role in determining the survival of germinating seeds, for example one of the roles of dormancy is to stagger germination to prevent mass growth under suboptimal conditions. The B3-domain transcription factor FUSCA3 (FUS3 is a master regulator of seed development and an important node in hormonal interaction networks in Arabidopsis thaliana. Its function has been mainly characterized during embryonic development, where FUS3 is highly expressed to promote seed maturation and dormancy by regulating ABA/GA levels. Results In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes. Conclusion In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying

  3. Droplet spreading and capillary imbibition in a porous medium: A coupled IB-VOF method based numerical study

    Science.gov (United States)

    Das, Saurish; Patel, H. V.; Milacic, E.; Deen, N. G.; Kuipers, J. A. M.

    2018-01-01

    We investigate the dynamics of a liquid droplet in contact with a surface of a porous structure by means of the pore-scale level, fully resolved numerical simulations. The geometrical details of the solid porous matrix are resolved by a sharp interface immersed boundary method on a Cartesian computational grid, whereas the motion of the gas-liquid interface is tracked by a mass conservative volume of fluid method. The numerical simulations are performed considering a model porous structure that is approximated by a 3D cubical scaffold with cylindrical struts. The effect of the porosity and the equilibrium contact angle (between the gas-liquid interface and the solid struts) on the spreading behavior, liquid imbibition, and apparent contact angle (between the gas-liquid interface and the porous base) are studied. We also perform several simulations for droplet spreading on a flat surface as a reference case. Gas-liquid systems of the Laplace number, La = 45 and La = 144 × 103 are considered neglecting the effect of gravity. We report the time exponent (n) and pre-factor (C) of the power law describing the evolution of the spreading diameter (S = Ctn) for different equilibrium contact angles and porosity. Our simulations reveal that the apparent or macroscopic contact angle varies linearly with the equilibrium contact angle and increases with porosity. Not necessarily for all the wetting porous structures, a continuous capillary drainage occurs, and we find that the rate of the capillary drainage very much depends on the fluid inertia. At La = 144 × 103, numerically we capture the capillary wave induced pinch-off and daughter droplet ejection. We observe that on the porous structure the pinch-off is weak compared to that on a flat plate.

  4. ECM using Edwards curves

    DEFF Research Database (Denmark)

    Bernstein, Daniel J.; Birkner, Peter; Lange, Tanja

    2013-01-01

    -arithmetic level are as follows: (1) use Edwards curves instead of Montgomery curves; (2) use extended Edwards coordinates; (3) use signed-sliding-window addition-subtraction chains; (4) batch primes to increase the window size; (5) choose curves with small parameters and base points; (6) choose curves with large...

  5. An Endosperm-Associated Cuticle Is Required for Arabidopsis Seed Viability, Dormancy and Early Control of Germination.

    Directory of Open Access Journals (Sweden)

    Julien De Giorgi

    2015-12-01

    Full Text Available Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared early and late during plant evolution, respectively. The cuticle is a waterproof film covering plant aerial organs preventing excessive water loss and protecting against biotic and abiotic stresses. Cutin, consisting of crosslinked fatty acid monomers, is the most abundant and studied cuticular component. Seeds are dry, metabolically inert structures promoting plant dispersal by keeping the plant embryo in an arrested protected state. In Arabidopsis thaliana seeds, the embryo is surrounded by a single cell endosperm layer itself surrounded by a seed coat layer, the testa. Whole genome analyses lead us to identify cutin biosynthesis genes as regulatory targets of the phytohormones gibberellins (GA and abscisic acid (ABA signaling pathways that control seed germination. Cutin-containing layers are present in seed coats of numerous species, including Arabidopsis, where they regulate permeability to outer compounds. However, the role of cutin in mature seed physiology and germination remains poorly understood. Here we identify in mature seeds a thick cuticular film covering the entire outer surface of the endosperm. This seed cuticle is defective in cutin-deficient bodyguard1 seeds, which is associated with alterations in endospermic permeability. Furthermore, mutants affected in cutin biosynthesis display low seed dormancy and viability levels, which correlates with higher levels of seed lipid oxidative stress. Upon seed imbibition cutin biosynthesis genes are essential to prevent endosperm cellular expansion and testa rupture in response to low GA synthesis. Taken together, our findings suggest that in the course of land plant evolution cuticular structures were co-opted to achieve key physiological seed properties.

  6. The role of the testa during development and in establishment of dormancy of the legume seed

    Science.gov (United States)

    Smýkal, Petr; Vernoud, Vanessa; Blair, Matthew W.; Soukup, Aleš; Thompson, Richard D.

    2014-01-01

    Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the “domestication syndrome.” Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy classes exist among plant species. Physical dormancy (often called hardseededness), as found in legumes, involves the development of a water-impermeable seed coat, caused by the presence of phenolics- and suberin-impregnated layers of palisade cells. The dormancy release mechanism primarily involves seed responses to temperature changes in the habitat, resulting in testa permeability to water. The underlying genetic controls in legumes have not been identified yet. However, positive correlation was shown between phenolics content (e.g., pigmentation), the requirement for oxidation and the activity of catechol oxidase in relation to pea seed dormancy, while epicatechin levels showed a significant positive correlation with soybean hardseededness. myeloblastosis family of transcription factors, WD40 proteins and enzymes of the anthocyanin biosynthesis pathway were involved in seed testa color in soybean, pea and Medicago, but were not tested directly in relation to seed dormancy. These phenolic compounds play important roles in defense against pathogens, as well as affecting the nutritional quality of products, and because of their health benefits, they are of industrial and medicinal interest. In this review, we discuss the role of the testa in mediating legume seed germination, with a focus on

  7. seed oil

    African Journals Online (AJOL)

    Wara

    Neem seed oil from the neem tree (Azadiracta indica) finds wide usage one of which is its utilization for cosmetics particularly .... obtained which is higher than that of olive oil 17. mgKOH/g (Davine ... The skin tolerance of shea fat employed as ...

  8. IMPACT OF LIQUID NITROGEN EXPOSURE ON SELECTED BIOCHEMICAL AND STRUCTURAL PARAMETERS OF HYDRATED Phaseolus vulgaris L. SEEDS.

    Science.gov (United States)

    Cejas, Inaudis; Rivas, Maribel; Nápoles, Lelurlys; Marrero, Pedro; Yabor, Lourdes; Aragón, Carlos; Pérez, Aurora; Engelmann, Florent; Martínez-Montero, Marcos Edel; Lorenzo, José Carlos

    2015-01-01

    It is well known that cryopreserving seeds with high water content is detrimental to survival, but biochemical and structural parameters of cryostored hydrated common bean seeds have not been published. The objective of this work was to study the effect of liquid nitrogen exposure on selected biochemical and structural parameters of hydrated Phaseolus vulgaris seeds. We cryopreserved seeds at various moisture contents and evaluated: germination; electrolyte leakage; fresh seed weight; levels of chlorophyll pigments, malondialdehyde, other aldehydes, phenolics and proteins; thickness of cotyledon epidermis, parenchyma, and starch storage parenchyma; and radicle and plumule lengths. Germination was totally inhibited when seeds were immersed in water for 50 min (moisture content of 38%, FW basis) before cryopreservation. The combined effects of seed water imbibition and cryostorage decreased phenolics (free, cell wall-linked, total), chlorophyll a and protein content. By contrast, electrolyte leakage and levels of chlorophyll b and other aldehydes increased as a result of the combination of these two experimental factors. These were the most significant effects observed during exposure of humid seed to liquid nitrogen. Further studies are still required to clarify the molecular events taking place in plant cells during cryostorage.

  9. The nuclear protein Poly(ADP-ribose) polymerase 3 (AtPARP3) is required for seed storability in Arabidopsis thaliana.

    Science.gov (United States)

    Rissel, D; Losch, J; Peiter, E

    2014-11-01

    The deterioration of seeds during prolonged storage results in a reduction of viability and germination rate. DNA damage is one of the major cellular defects associated with seed deterioration. It is provoked by the formation of reactive oxygen species (ROS) even in the quiescent state of the desiccated seed. In contrast to other stages of seed life, DNA repair during storage is hindered through the low seed water content; thereby DNA lesions can accumulate. To allow subsequent seedling development, DNA repair has thus to be initiated immediately upon imbibition. Poly(ADP-ribose) polymerases (PARPs) are important components in the DNA damage response in humans. Arabidopsis thaliana contains three homologues to the human HsPARP1 protein. Of these three, only AtPARP3 was very highly expressed in seeds. Histochemical GUS staining of embryos and endosperm layers revealed strong promoter activity of AtPARP3 during all steps of germination. This coincided with high ROS activity and indicated a role of the nuclear-localised AtPARP3 in DNA repair during germination. Accordingly, stored parp3-1 mutant seeds lacking AtPARP3 expression displayed a delay in germination as compared to Col-0 wild-type seeds. A controlled deterioration test showed that the mutant seeds were hypersensitive to unfavourable storage conditions. The results demonstrate that AtPARP3 is an important component of seed storability and viability. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. ABA crosstalk with ethylene and nitric oxide in seed dormancy and germination

    Directory of Open Access Journals (Sweden)

    Erwann eArc

    2013-03-01

    Full Text Available Dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. It has been clearly demonstrated that dormancy is induced by abscisic acid (ABA during seed development on the mother plant. After seed dispersal, germination is preceded by a decline in ABA in imbibed seeds, which results from ABA catabolism through 8’-hydroxylation. The hormonal balance between ABA and gibberellins (GAs has been shown to act as an integrator of environmental cues to maintain dormancy or activate germination. The interplay of ABA with other endogenous signals is however less documented. In numerous species, ethylene counteracts ABA signaling pathways and induces germination. In Brassicaceae seeds, ethylene prevents the inhibitory effects of ABA on endosperm cap weakening, thereby facilitating endosperm rupture and radicle emergence. Moreover, enhanced seed dormancy in Arabidopsis ethylene-insensitive mutants results from greater ABA sensitivity. Conversely, ABA limits ethylene action by down-regulating its biosynthesis. Nitric oxide (NO has been proposed as a common actor in the ABA and ethylene crosstalk in seed. Indeed, convergent evidence indicates that NO is produced rapidly after seed imbibition and promotes germination by inducing the expression of the ABA 8’-hydroxylase gene, CYP707A2, and stimulating ethylene production. The role of NO and other nitrogen-containing compounds, such as nitrate, in seed dormancy breakage and germination stimulation has been reported in several species. This review will describe our current knowledge of ABA crosstalk with ethylene and NO, both volatile compounds that have been shown to counteract ABA action in seeds and to improve dormancy release and germination.

  11. The effect of ZnO nanoparticles on improved oil recovery in spontaneous imbibition mechanism of heavy oil production

    Science.gov (United States)

    Tajmiri, M.; Ehsani, M. R.; Mousavi, S. M.; Roayaei, E.; Emadi, A.

    2015-07-01

    Spontaneous imbibition (SI) gets a controversial subject in oil- wet carbonate reservoirs. The new concept of nanoparticles applications in an EOR area have been recently raised by researches about oil viscosity reduction and generate emulsion without surfactant. But a lot of questions have been remained about which nanoparticles can alter wettability from oil- wet to water- wet to improve oil recovery. This study introduces the new idea of adding ZnO nanoparticles (0.2%wt concentration) by experimental work on oil recovery. The main goals of this research were to prove that ZnO nanoparticles have the ability to reduce viscosity and also alter wettability. The ultimate objective was to determine the potential of these nanoparticles to imbibe into and displace oil. Through the use of Amott- cell, laboratory tests were conducted in two experiments on four cylindrical core samples (three sandstones and one carbonate) were taken from real Iranian heavy oil reservoir. In the first experiment, core samples were saturated by crude oil and in the second experiment, nanoparticles were flooding into core samples and then saturated by crude oil for about two weeks and after that they were immersed in distilled water and the amount of recovery was monitored during 30 days for both tests. We expected that ZnO nanoparticles decreased the surface tension which reduced the capillary forces through SI and wettability alteration took place towards a more water-wet system and caused the oil relative permeability to increase which dominated the gravitational forces to pull out the oil. Our results proved this expectation from ZnO nanoparticles clearly because carbonate core was oil- wet and the capillary pressure was high and negative to push water into the core so the original oil in place (OOIP) was zero whereas by adding ZnO nanoparticles OOIP was increased to 8.89%. SI yielded recovery values from 17.3, 2 and 15 without nanoparticles to 20.68, 17.57 and 36.2 % OOIP with

  12. Contractibility of curves

    Directory of Open Access Journals (Sweden)

    Janusz Charatonik

    1991-11-01

    Full Text Available Results concerning contractibility of curves (equivalently: of dendroids are collected and discussed in the paper. Interrelations tetween various conditions which are either sufficient or necessary for a curve to be contractible are studied.

  13. New design of experiment combined with UV-Vis spectroscopy for extraction and estimation of polyphenols from Basil seeds, Red seeds, Sesame seeds and Ajwan seeds

    Science.gov (United States)

    Mabood, Fazal; Gilani, Syed Abdullah; Hussain, Javid; Alshidani, Sulaiman; Alghawi, Said; Albroumi, Mohammed; Alameri, Saif; Jabeen, Farah; Hussain, Zahid; Al-Harrasi, Ahmed; Al Abri, Zahra K. M.; Farooq, Saima; Naureen, Zakira; Hamaed, Ahmad; Rasul Jan, M.; Shah, Jasmin

    2017-05-01

    New experimental designs for the extraction of polyphenols from different seeds including Basil seed, Red seed, Sesame seeds and Ajwan seeds were investigated. Four variables the concentration and volume of methanol and NaOH solutions as well as the temperature and time of extraction were varied to see their effect on total phenol extraction. The temperature was varied in the range from 25 °C to 200 °C while the time in the range from 30 to 200 minutes. Response surface methodology was used to optimize the extraction parameters. The estimation of polyphenols was measured through phenols reduction UV-Vis spectroscopic method of phosphotungstic-phosphomolybdic acids (Folin-Ciocalteu's reagent). Calibration curve was made by using tannic acid as a polyphenols standard in the concentration range from 0.1 to 10 ppm. The regression line obtained shows the value of correlation coefficient i.e. R = 0.930 and Root mean square error of cross validation (RMSEC) value of 0.0654. The Basil seeds were found containing the highest amount of total phenols i.e. 785.76 mg/100 g. While the Sesame seeds having the least amount i.e. 33.08 mg/100 g. The Ajwan seeds and the Red seeds are containing the medium amounts i.e. 379 mg/100 g and 220.54 mg/100 g respectively.

  14. New design of experiment combined with UV-Vis spectroscopy for extraction and estimation of polyphenols from Basil seeds, Red seeds, Sesame seeds and Ajwan seeds.

    Science.gov (United States)

    Mabood, Fazal; Gilani, Syed Abdullah; Hussain, Javid; Alshidani, Sulaiman; Alghawi, Said; Albroumi, Mohammed; Alameri, Saif; Jabeen, Farah; Hussain, Zahid; Al-Harrasi, Ahmed; Al Abri, Zahra K M; Farooq, Saima; Naureen, Zakira; Hamaed, Ahmad; Rasul Jan, M; Shah, Jasmin

    2017-05-05

    New experimental designs for the extraction of polyphenols from different seeds including Basil seed, Red seed, Sesame seeds and Ajwan seeds were investigated. Four variables the concentration and volume of methanol and NaOH solutions as well as the temperature and time of extraction were varied to see their effect on total phenol extraction. The temperature was varied in the range from 25°C to 200°C while the time in the range from 30 to 200minutes. Response surface methodology was used to optimize the extraction parameters. The estimation of polyphenols was measured through phenols reduction UV-Vis spectroscopic method of phosphotungstic-phosphomolybdic acids (Folin-Ciocalteu's reagent). Calibration curve was made by using tannic acid as a polyphenols standard in the concentration range from 0.1 to 10ppm. The regression line obtained shows the value of correlation coefficient i.e. R=0.930 and Root mean square error of cross validation (RMSEC) value of 0.0654. The Basil seeds were found containing the highest amount of total phenols i.e. 785.76mg/100g. While the Sesame seeds having the least amount i.e. 33.08mg/100g. The Ajwan seeds and the Red seeds are containing the medium amounts i.e. 379mg/100g and 220.54mg/100g respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Translatome profiling in dormant and nondormant sunflower (Helianthus annuus) seeds highlights post-transcriptional regulation of germination.

    Science.gov (United States)

    Layat, Elodie; Leymarie, Juliette; El-Maarouf-Bouteau, Hayat; Caius, José; Langlade, Nicolas; Bailly, Christophe

    2014-12-01

    Seed dormancy, which blocks germination in apparently favourable conditions, is a key regulatory control point of plant population establishment. As germination requires de novo translation, its regulation by dormancy is likely to be related to the association of individual transcripts to polysomes. Here, the polysome-associated mRNAs, that is, the translatome, were fractionated and characterized with microarrays in dormant and nondormant sunflower (Helianthus annuus) embryos during their imbibition at 10°C, a temperature preventing germination of dormant embryos. Profiling of mRNAs in polysomal complexes revealed that the translatome differs between germinating and nongerminating embryos. Association of transcripts with polysomes reached a maximum after 15 h of imbibition; at this time-point 194 polysome-associated transcripts were specifically found in nondormant embryos and 47 in dormant embryos only. The proteins corresponding to the polysomal mRNAs in nondormant embryos appeared to be very pertinent for germination and were involved mainly in transport, regulation of transcription or cell wall modifications. This work demonstrates that seed germination results from a timely regulated and selective recruitment of mRNAs to polysomes, thus opening novel fields of investigation for the understanding of this developmental process. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  16. Identification of HDA15-PIF1 as a key repression module directing the transcriptional network of seed germination in the dark.

    Science.gov (United States)

    Gu, Dachuan; Chen, Chia-Yang; Zhao, Minglei; Zhao, Linmao; Duan, Xuewu; Duan, Jun; Wu, Keqiang; Liu, Xuncheng

    2017-07-07

    Light is a major external factor in regulating seed germination. Photoreceptor phytochrome B (PHYB) plays a predominant role in promoting seed germination in the initial phase after imbibition, partially by repressing phytochrome-interacting factor1 (PIF1). However, the mechanism underlying the PHYB-PIF1-mediated transcription regulation remains largely unclear. Here, we identified that histone deacetylase15 (HDA15) is a negative component of PHYB-dependent seed germination. Overexpression of HDA15 in Arabidopsis inhibits PHYB-dependent seed germination, whereas loss of function of HDA15 increases PHYB-dependent seed germination. Genetic evidence indicated that HDA15 acts downstream of PHYB and represses seed germination dependent on PIF1. Furthermore, HDA15 interacts with PIF1 both in vitro and in vivo. Genome-wide transcriptome analysis revealed that HDA15 and PIF1 co-regulate the transcription of the light-responsive genes involved in multiple hormonal signaling pathways and cellular processes in germinating seeds in the dark. In addition, PIF1 recruits HDA15 to the promoter regions of target genes and represses their expression by decreasing the histone H3 acetylation levels in the dark. Taken together, our analysis uncovered the role of histone deacetylation in the light-regulated seed germination process and identified that HDA15-PIF1 acts as a key repression module directing the transcription network of seed germination. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Organic leek seed production - securing seed quality

    DEFF Research Database (Denmark)

    Deleuran, Lise Christina; Boelt, Birte

    2011-01-01

    To maintain integrity in organic farming, availability of organically produced GM-free seed of varieties adapted to organic production systems is of vital impor-tance. Despite recent achievements, organic seed supply for a number of vegetable species is insufficient. Still, in many countries...... seeds. Tunnel production is a means of securing seed of high genetic purity and quality, and organic leek (Allium porrum L.) seed production was tested in tunnels in Denmark. The present trial focused on steckling size and in all years large stecklings had a positive effect on both seed yield...

  18. Organic Leek Seed Production - Securing Seed Quality

    DEFF Research Database (Denmark)

    Deleuran, L C; Boelt, B

    2011-01-01

    To maintain integrity in organic farming, availability of organically produced GM-free seed of varieties adapted to organic production systems is of vital impor-tance. Despite recent achievements, organic seed supply for a number of vegetable species is insufficient. Still, in many countries...... seeds. Tunnel production is a means of securing seed of high genetic purity and quality, and organic leek (Allium porrum L.) seed production was tested in tunnels in Denmark. The present trial focused on steckling size and in all years large stecklings had a positive effect on both seed yield...

  19. Seed germination in relation to the invasiveness in spiny amaranth and edible amaranth in Xishuangbanna, SW China.

    Science.gov (United States)

    Ye, Juan; Wen, Bin

    2017-01-01

    Both spiny and edible amaranths (Amaranthus spinosus and A. tricolor) are exotic annuals in China that produce numerous small seeds every year. Spiny amaranth has become a successful invader and a troublesome weed in Xishuangbanna, but edible amaranth has not, although it is widely grown as a vegetable there. As seed germination is one of the most important life-stages contributing to the ability of a plant to become invasive, we conducted experiments to compare the effects of high temperature and water stress on seed germination in two varieties each of spiny amaranth and edible amaranth. Overall, the seeds of both amaranth species exhibited adaptation to high temperature and water stress, including tolerance to ground temperatures of 70°C for air-dried seeds, which is consistent with their behavior in their native ranges in the tropics. As expected, the invasive spiny amaranth seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 45°C, and to imbibition-desiccation treatment, compared to edible amaranth seeds. Unexpectedly, edible amaranth seeds exhibited higher germination at extreme temperatures (10°C, 15°C, and 40°C), and at lower water potential (below -0.6 MPa). It is likely that cultivation of edible amaranth has selected seed traits that include rapid germination and germination under stressful conditions, either of which, under natural conditions, may result in the death of most germinating edible amaranth seeds and prevent them from becoming invasive weeds in Xishuangbanna. This study suggests that rapid germination and high germination under stress conditions-excellent seed traits for crops and for many invasive species-might be a disadvantage under natural conditions if these traits are asynchronous with natural local conditions that support successful germination.

  20. Seed germination in relation to the invasiveness in spiny amaranth and edible amaranth in Xishuangbanna, SW China.

    Directory of Open Access Journals (Sweden)

    Juan Ye

    Full Text Available Both spiny and edible amaranths (Amaranthus spinosus and A. tricolor are exotic annuals in China that produce numerous small seeds every year. Spiny amaranth has become a successful invader and a troublesome weed in Xishuangbanna, but edible amaranth has not, although it is widely grown as a vegetable there. As seed germination is one of the most important life-stages contributing to the ability of a plant to become invasive, we conducted experiments to compare the effects of high temperature and water stress on seed germination in two varieties each of spiny amaranth and edible amaranth. Overall, the seeds of both amaranth species exhibited adaptation to high temperature and water stress, including tolerance to ground temperatures of 70°C for air-dried seeds, which is consistent with their behavior in their native ranges in the tropics. As expected, the invasive spiny amaranth seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 45°C, and to imbibition-desiccation treatment, compared to edible amaranth seeds. Unexpectedly, edible amaranth seeds exhibited higher germination at extreme temperatures (10°C, 15°C, and 40°C, and at lower water potential (below -0.6 MPa. It is likely that cultivation of edible amaranth has selected seed traits that include rapid germination and germination under stressful conditions, either of which, under natural conditions, may result in the death of most germinating edible amaranth seeds and prevent them from becoming invasive weeds in Xishuangbanna. This study suggests that rapid germination and high germination under stress conditions-excellent seed traits for crops and for many invasive species-might be a disadvantage under natural conditions if these traits are asynchronous with natural local conditions that support successful germination.

  1. Gene expression analysis by cDNA-AFLP highlights a set of new signaling networks and translational control during seed dormancy breaking in Nicotiana plumbaginifolia.

    Science.gov (United States)

    Bove, Jérôme; Lucas, Philippe; Godin, Béatrice; Ogé, Laurent; Jullien, Marc; Grappin, Philippe

    2005-03-01

    Seed dormancy in Nicotiana plumbaginifolia is characterized by an abscisic acid accumulation linked to a pronounced germination delay. Dormancy can be released by 1 year after-ripening treatment. Using a cDNA-amplified fragment length polymorphism (cDNA-AFLP) approach we compared the gene expression patterns of dormant and after-ripened seeds, air-dry or during one day imbibition and analyzed 15,000 cDNA fragments. Among them 1020 were found to be differentially regulated by dormancy. Of 412 sequenced cDNA fragments, 83 were assigned to a known function by search similarities to public databases. The functional categories of the identified dormancy maintenance and breaking responsive genes, give evidence that after-ripening turns in the air-dry seed to a new developmental program that modulates, at the RNA level, components of translational control, signaling networks, transcriptional control and regulated proteolysis.

  2. JUMPING THE CURVE

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-01-01

    Full Text Available This paper explores the notion ofjump ing the curve,following from Handy 's S-curve onto a new curve with new rules policies and procedures. . It claims that the curve does not generally lie in wait but has to be invented by leadership. The focus of this paper is the identification (mathematically and inferentially ofthat point in time, known as the cusp in catastrophe theory, when it is time to change - pro-actively, pre-actively or reactively. These three scenarios are addressed separately and discussed in terms ofthe relevance ofeach.

  3. Overcoming dormancy in seeds of cotton-silk tree

    Directory of Open Access Journals (Sweden)

    Irinaldo Lima do Nascimento

    2012-06-01

    Full Text Available Cotton-silk tree Ceiba glaziovii (kuntze k. Schu belongs to family Bombacaceas and is locally known as barriguda. It is widely used in landscaping and reforestation, neverdeless seed dormancy affects reproduction in this species. The objective of this study was to evaluate the effectiveness of different methods to overcome dormancy in the germination process. Treatments included mechanical scarification with 85-grit sandpaper, chemical scarification with concentrated sulfuric acid for 5, 10, 15 and 20 minutes, physical scarification with hot water at 60°, 70°, 80°and 90° C for one minute, imbibition in distilled water for 24, 48 and 72 hours, oven heating at 65° C for 1, 2, 3 and 4 hours, and a control treatment. Each treatment included four replicates of 25 seeds, using a completely randomized experimental design, and means were compared by the Scott-Knott test at the 5% probability level. Assessed parameters included emergence percentage, emergence rate index, dry matter and length of plants. The most recommended treatments were mechanical scarification, immersion in sulfuric acid for 5, 10 and 15 minutes and immersion in distilled water for 48 hours.

  4. Etude fondamentale de l'imbibition dans un réservoir fissuré Basic Research on Inbibition in a Fractured Reservoir

    Directory of Open Access Journals (Sweden)

    Iffly R.

    2006-11-01

    Full Text Available L'efficacité du balayage d'un gisement fissuré par de l'eau d'injection dépend étroitement de l'importance et de la vitesse d'imbibition de l'eau par les blocs matriciels. De nombreuses expériences de laboratoire, réalisées sur des échantillons de roche et avec les fluides provenant d'un gisement exploité par Elf, ont permis de préciser l'influence, sur la récupération de l'huile, de la hauteur et de la perméabilité des blocs, ainsi que des conditions régnant à leurs limites (certaines fissures peuvent contenir, soit de l'eau, soit de l'huile, soit encore être étanches. Les résultats mettent en évidence le rôle essentiel des liaisons physico-chimiques entre l'eau de gisement, l'eau injectée, l'huile et la roche, à tout moment de l'imbibition. De légers écarts dans la composition lithologique de la roche peuvent modifier considérablement les lois de récupération. Par ailleurs, la présence dans les fluides de certaines molécules organiques peut influencer la récupération de l'huile beaucoup plus que ce que l'on pourrait attendre a priori des seules variations du terme a cos 6,. Comme ces liaisons physico-chimiques sont encore mal connues, donc non modélisables, il n'est en général pas légitime de procéder à des expériences d'imbibition avec des fluides et/ou des échantillons de roche ne provenant pas du gisement étudié. Dans ces conditions, les résultats de cette étude sont nécessairement spécifiques du champ considéré. Toutefois, les méthodes utilisées, l'analyse des résultats qui est faite, ainsi que l'influence des principaux paramètres sur ces résultats, présentent un degré de généralité évident. Les mesures de laboratoire, complétées par des simulations numériques, ont conduit à un ensemble cohérent de résultats permettant de comprendre le rôle respectif de la gravité, de la capillarité, des conditions aux limites et des effets d'extrémité, entre autres. Waterflood

  5. Tornado-Shaped Curves

    Science.gov (United States)

    Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio

    2017-01-01

    In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.

  6. Simulating Supernova Light Curves

    International Nuclear Information System (INIS)

    Even, Wesley Paul; Dolence, Joshua C.

    2016-01-01

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth's atmosphere.

  7. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  8. Image scaling curve generation

    NARCIS (Netherlands)

    2012-01-01

    The present invention relates to a method of generating an image scaling curve, where local saliency is detected in a received image. The detected local saliency is then accumulated in the first direction. A final scaling curve is derived from the detected local saliency and the image is then

  9. Image scaling curve generation.

    NARCIS (Netherlands)

    2011-01-01

    The present invention relates to a method of generating an image scaling curve, where local saliency is detected in a received image. The detected local saliency is then accumulated in the first direction. A final scaling curve is derived from the detected local saliency and the image is then

  10. Tempo curves considered harmful

    NARCIS (Netherlands)

    Desain, P.; Honing, H.

    1993-01-01

    In the literature of musicology, computer music research and the psychology of music, timing or tempo measurements are mostly presented in the form of continuous curves. The notion of these tempo curves is dangerous, despite its widespread use, because it lulls its users into the false impression

  11. Comparative metabolome analysis of wheat embryo and endosperm reveals the dynamic changes of metabolites during seed germination.

    Science.gov (United States)

    Han, Caixia; Zhen, Shoumin; Zhu, Gengrui; Bian, Yanwei; Yan, Yueming

    2017-06-01

    In this study, we performed the first comparative metabolomic analysis of the wheat embryo and endosperm during seed germination using GC-MS/MS. In total, 82 metabolites were identified in the embryo and endosperm. Principal component analysis (PCA), metabolite-metabolite correlation and hierarchical cluster analysis (HCA) revealed distinct dynamic changes in metabolites between the embryo and endosperm during seed germination. Generally, the metabolite changes in the embryo were much greater than those in the endosperm, suggesting that the embryo is more active than the endosperm during seed germination. Most amino acids were upregulated in both embryo and endosperm, while polysaccharides and organic acids associated with sugars were mainly downregulated in the embryo. Most of the sugars showed an upregulated trend in the endosperm, but significant changes in lipids occurred only in the embryo. Our results suggest that the embryo mobilises mainly protein and lipid metabolism, while the endosperm mobilises storage starch and minor protein metabolism during seed germination. The primary energy was generated mainly in the embryo by glycolysis during seed imbibition. The embryo containing most of the genetic information showed increased nucleotides during seed germination process, indicating more active transcription and translation metabolisms. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  13. Seed improvement by selection and invigoration Seleção e envigoramento como técnicas para o aprimoramento do desempenho de sementes

    Directory of Open Access Journals (Sweden)

    A.A. Powell

    1998-01-01

    Full Text Available The basis of differences in seed quality are described for two groups of crops, grain legumes and vegetables and approaches to the improvement of quality are proposed. In grain legumes the major factors affecting seed quality are imbibition damage, seed ageing and their interaction. It is proposed that use of seed vigour tests, specifically the electrical conductivity test, to identify the incidence of imbibition damage and ageing allows the selection of seed lots for sale and for use under different field conditions. Alternatively in grain legume species in which there is a genotypic influence on predisposition to imbibition damage the approach to seed improvement may lie through selection in breeding programmes. Thus identification of testa characteristics that favour slow imbibition would enable selection for these characteristics. Seed ageing is also the major cause of reduced seed quality in vegetable species, leading to slow and asynchronous germination. An approach to their seed improvement has been the development of seed invigoration treatments based on seed hydration. The principle of these treatments is described and several treatments outlined, with emphasis being given to aerated hydration, a treatment completed within 36h. The physiological basis of improvement by invigoration is discussed.Neste trabalho, são descritas diferenças básicas na qualidade de sementes de leguminosas e hortaliças, e propostos procedimentos para a melhoria de seu desempenho. Os principais fatores que afetam a qualidade de sementes de leguminosas são as injurias durante a embebição, o envelhecimento e a interação entre esses fatores. Considera-se que a utilização de testes de vigor, principalmente o de condutividade elétrica, para a identificação de injurias durante a embebição e o grau de envelhecimento, permite a seleção de lotes para a comercialização e uso sob diferentes condições de campo. A alternativa, em leguminosas, onde h

  14. A Classification Method for Seed Viability Assessment with Infrared Thermography

    Directory of Open Access Journals (Sweden)

    Sen Men

    2017-04-01

    Full Text Available This paper presents a viability assessment method for Pisum sativum L. seeds based on the infrared thermography technique. In this work, different artificial treatments were conducted to prepare seeds samples with different viability. Thermal images and visible images were recorded every five minutes during the standard five day germination test. After the test, the root length of each sample was measured, which can be used as the viability index of that seed. Each individual seed area in the visible images was segmented with an edge detection method, and the average temperature of the corresponding area in the infrared images was calculated as the representative temperature for this seed at that time. The temperature curve of each seed during germination was plotted. Thirteen characteristic parameters extracted from the temperature curve were analyzed to show the difference of the temperature fluctuations between the seeds samples with different viability. With above parameters, support vector machine (SVM was used to classify the seed samples into three categories: viable, aged and dead according to the root length, the classification accuracy rate was 95%. On this basis, with the temperature data of only the first three hours during the germination, another SVM model was proposed to classify the seed samples, and the accuracy rate was about 91.67%. From these experimental results, it can be seen that infrared thermography can be applied for the prediction of seed viability, based on the SVM algorithm.

  15. Learning Curve? Which One?

    Directory of Open Access Journals (Sweden)

    Paulo Prochno

    2004-07-01

    Full Text Available Learning curves have been studied for a long time. These studies provided strong support to the hypothesis that, as organizations produce more of a product, unit costs of production decrease at a decreasing rate (see Argote, 1999 for a comprehensive review of learning curve studies. But the organizational mechanisms that lead to these results are still underexplored. We know some drivers of learning curves (ADLER; CLARK, 1991; LAPRE et al., 2000, but we still lack a more detailed view of the organizational processes behind those curves. Through an ethnographic study, I bring a comprehensive account of the first year of operations of a new automotive plant, describing what was taking place on in the assembly area during the most relevant shifts of the learning curve. The emphasis is then on how learning occurs in that setting. My analysis suggests that the overall learning curve is in fact the result of an integration process that puts together several individual ongoing learning curves in different areas throughout the organization. In the end, I propose a model to understand the evolution of these learning processes and their supporting organizational mechanisms.

  16. Genotype x year interaction for cooking time and its correlation with mass and imbibition percentage on food type soybean/ Interação genótipo x ano para tempo de cozimento e sua correlação com a massa e percentagem de embebição em soja tipo alimento

    Directory of Open Access Journals (Sweden)

    Anderson Paranzini Faria

    2005-06-01

    Full Text Available Brazil is second in soybean world production and it is responsable for 26.8% of the global production. Soybean grains have 40% of protein and 20% of oil. Soybean grains are rich in isoflavones, which prevent degenerative cronic diseases. With the increasing use of soybean for human consumption, there is necessity to study how the environment effects the grain technological characteristics. Many technological processes in soybean industrialization involve imbibition and cooking. The objective of this work was to select soybean genotypes for human consumption, by determining cooking time and its correlation with mass and grain imbibition percentages, taking into consideration genotype, agricultural year and their interaction. The following traits were determined: weight of one hundred seeds, imbibition percentage and cooking time. Cooking time was measured by a modified Mattson Machine. Significant differences (O Brasil é o segundo produtor mundial de soja (Glycine Max (L. Merrill, sendo responsável por 26,8% da safra global. A soja possuí 40% de proteína e 20% de óleo. A soja é rica em isoflavonas, as quais atuam na prevenção de doenças crônicas degenerativas. Com o crescente uso da soja na alimentação humana, há necessidade de se estudar como o ambiente influencia nas características tecnológicas do grão. Muitos dos processos tecnológicos de industrialização da soja possuem como ponto inicial a hidratação e posterior cozimento da soja. O objetivo deste trabalho foi selecionar genótipos de soja para o consumo humano, através da determinação do tempo de cozimento e sua correlação com a massa e percentagem de embebição dos grãos, levando-se em consideração genótipo, ano agrícola e sua interação. Foram determinados os seguintes caracteres: massa de cem grãos, percentagem de embebição e tempo de cozimento. O tempo de cozimento foi determinado por meio da Máquina de Mattson adaptada. Foram encontradas diferen

  17. Role of protein and mRNA oxidation in seed dormancy and germination

    Directory of Open Access Journals (Sweden)

    hayat eel-maarouf-bouteau

    2013-04-01

    Full Text Available Reactive oxygen species (ROS are key players in the regulation of seed germination and dormancy. Although their regulated accumulation is a prerequisite for germination, the cellular basis of their action remains unknown, but very challenging to elucidate due to the lack of specificity of these compounds that can potentially react with all biomolecules. Among these, nucleic acids and proteins are very prone to oxidative damage. RNA is highly sensitive to oxidation because of its single-stranded structure and the absence of a repair system. Oxidation of mRNAs induces their decay through processing bodies or results in the synthesis of aberrant proteins through altered translation. Depending on the oxidized amino acid, ROS damage of proteins can be irreversible (i.e. carbonylation thus triggering the degradation of the oxidized proteins by the cytosolic 20S proteasome or can be reversed through the action of thioredoxins, peroxiredoxins or glutaredoxins (cysteine oxidation or by methionine sulfoxide reductase (methionine oxidation. Seed dormancy alleviation in the dry state, referred to as after-ripening, requires both selective mRNA oxidation and protein carbonylation. Similarly, seed imbibition of non-dormant seeds is associated with targeted oxidation of a subset of proteins. Altogether, these specific features testify that such oxidative modifications play important role in commitment of the cellular functioning toward germination completion.

  18. Quantitative trait loci associated with seed and seedling traits in Lactuca.

    Science.gov (United States)

    Argyris, Jason; Truco, María José; Ochoa, Oswaldo; Knapp, Steven J; Still, David W; Lenssen, Ger M; Schut, Johan W; Michelmore, Richard W; Bradford, Kent J

    2005-11-01

    Seed and seedling traits related to germination and stand establishment are important in the production of cultivated lettuce (Lactuca sativa L.). Six seed and seedling traits segregating in a L. sativa cv. Salinas x L. serriola recombinant inbred line population consisting of 103 F8 families revealed a total of 17 significant quantitative trait loci (QTL) resulting from three seed production environments. Significant QTL were identified for germination in darkness, germination at 25 and 35 degrees C, median maximum temperature of germination, hypocotyl length at 72 h post-imbibition, and plant (seedling) quality. Some QTL for germination and early seedling growth characteristics were co-located, suggestive of pleiotropic loci regulating these traits. A single QTL (Htg6.1) described 25 and 23% of the total phenotypic variation for high temperature germination in California- and Netherlands-grown populations, respectively, and was significant between 33 and 37 degrees C. Additionally, Htg6.1 showed significant epistatic interactions with other Htg QTL and a consistent effect across all the three seed production environments. L. serriola alleles increased germination at these QTL. The estimate of narrow-sense heritability (h2) of Htg6.1 was 0.84, indicating potential for L. serriola as a source of germination thermotolerance for lettuce introgression programs.

  19. The crime kuznets curve

    OpenAIRE

    Buonanno, Paolo; Fergusson, Leopoldo; Vargas, Juan Fernando

    2014-01-01

    We document the existence of a Crime Kuznets Curve in US states since the 1970s. As income levels have risen, crime has followed an inverted U-shaped pattern, first increasing and then dropping. The Crime Kuznets Curve is not explained by income inequality. In fact, we show that during the sample period inequality has risen monotonically with income, ruling out the traditional Kuznets Curve. Our finding is robust to adding a large set of controls that are used in the literature to explain the...

  20. Bond yield curve construction

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available In the broadest sense, yield curve indicates the market's view of the evolution of interest rates over time. However, given that cost of borrowing it closely linked to creditworthiness (ability to repay, different yield curves will apply to different currencies, market sectors, or even individual issuers. As government borrowing is indicative of interest rate levels available to other market players in a particular country, and considering that bond issuance still remains the dominant form of sovereign debt, this paper describes yield curve construction using bonds. The relationship between zero-coupon yield, par yield and yield to maturity is given and their usage in determining curve discount factors is described. Their usage in deriving forward rates and pricing related derivative instruments is also discussed.

  1. SRHA calibration curve

    Data.gov (United States)

    U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation. This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...

  2. Bragg Curve Spectroscopy

    International Nuclear Information System (INIS)

    Gruhn, C.R.

    1981-05-01

    An alternative utilization is presented for the gaseous ionization chamber in the detection of energetic heavy ions, which is called Bragg Curve Spectroscopy (BCS). Conceptually, BCS involves using the maximum data available from the Bragg curve of the stopping heavy ion (HI) for purposes of identifying the particle and measuring its energy. A detector has been designed that measures the Bragg curve with high precision. From the Bragg curve the range from the length of the track, the total energy from the integral of the specific ionization over the track, the dE/dx from the specific ionization at the beginning of the track, and the Bragg peak from the maximum of the specific ionization of the HI are determined. This last signal measures the atomic number, Z, of the HI unambiguously

  3. ROBUST DECLINE CURVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sutawanir Darwis

    2012-05-01

    Full Text Available Empirical decline curve analysis of oil production data gives reasonable answer in hyperbolic type curves situations; however the methodology has limitations in fitting real historical production data in present of unusual observations due to the effect of the treatment to the well in order to increase production capacity. The development ofrobust least squares offers new possibilities in better fitting production data using declinecurve analysis by down weighting the unusual observations. This paper proposes a robustleast squares fitting lmRobMM approach to estimate the decline rate of daily production data and compares the results with reservoir simulation results. For case study, we usethe oil production data at TBA Field West Java. The results demonstrated that theapproach is suitable for decline curve fitting and offers a new insight in decline curve analysis in the present of unusual observations.

  4. Power Curve Measurements FGW

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Federici, Paolo

    This report describes power curve measurements carried out on a given turbine in a chosen period. The measurements are carried out in accordance to IEC 61400-12-1 Ed. 1 and FGW Teil 2.......This report describes power curve measurements carried out on a given turbine in a chosen period. The measurements are carried out in accordance to IEC 61400-12-1 Ed. 1 and FGW Teil 2....

  5. Curves and Abelian varieties

    CERN Document Server

    Alexeev, Valery; Clemens, C Herbert; Beauville, Arnaud

    2008-01-01

    This book is devoted to recent progress in the study of curves and abelian varieties. It discusses both classical aspects of this deep and beautiful subject as well as two important new developments, tropical geometry and the theory of log schemes. In addition to original research articles, this book contains three surveys devoted to singularities of theta divisors, of compactified Jacobians of singular curves, and of "strange duality" among moduli spaces of vector bundles on algebraic varieties.

  6. Genotypic variability and mutant identification in cicer arietinum L. by seed storage protein profiling

    International Nuclear Information System (INIS)

    Hameed, A.; Iqbal, N.; Shah, T.M.

    2012-01-01

    A collection of thirty-four chickpea genotypes, including five kabuli and twenty-nine desi, were analyzed by SDS-PAGE for seed storage protein profiling. Total soluble seed proteins were resolved on 12% gels. A low level of variability was observed in desi as compared to kabuli genotypes. Dendrogram based on electrophoretic data clustered the thirty-four genotypes in four major groups. As large number of desi genotypes illustrated identical profiles, therefore could not be differentiated on the basis of seed storage protein profiles. One kabuli genotype ILC-195 found to be the most divergent showing 86% similarity with all other genotypes. ILC-195 can be distinguished from its mutant i.e., CM-2000 and other kabuli genotypes on the basis of three peptides i.e. SSP-66, SSP-43 and SSP-39. Some proteins peptides were found to be genotype specific like SSP-26 for ICCV-92311. Uniprot and NCBI protein databases were searched for already reported and characterized seed storage proteins in chickpea. Among 33 observed peptides, only six seed storages proteins from chickpea source were available in databases. On the basis of molecular weight similarity, identified peptides were SSP-64 as Serine/Threonine dehydratase, SSP-56 as Alpha-amylase inhibitor, SSP-50 as Provicillin, SSP-39 as seed imbibition protein, SSP-35 as Isoflavane reductase and SSP-19 as lipid transport protein. Highest variability was observed in vicillin subunits and beta subunits of legumins and its polymorphic forms. In conclusion, seed storage profiling can be economically used to asses the genetic variation, phylogenetic relationship and as markers to differentiate mutants from their parents. (author)

  7. Método para determinar la cantidad de agua de imbibición a utilizar en la caña // Methodology to determine the amount of imbibition water to use in the sugar cane industry.

    Directory of Open Access Journals (Sweden)

    Félix González-Pérez

    2010-01-01

    Full Text Available ResumenSe hizo un estudio del uso del agua de imbibición en la industria del azúcar de caña de Cuba y, serevisaron más de 200 fuentes bibliográficas llegándose a conclusiones importantes en cuanto a lacantidad y temperatura del agua de imbibición, así como la revisión del esquema de imbibición másutilizado.A partir de aquí se obtiene un procedimiento para determinar la cantidad óptima de agua deimbibición teniendo en cuenta los precios actualizados del azúcar y el bagazo como combustible ypara otros usos, Es utilizado para su validación en dos empresas azucareras de la provincia deCienfuegos, se obtuvo que en las condiciones económicas actuales, es recomendable utilizar entre10,4 – 15,4 % caña en dependencia del uso que se le dé al bagazo y no entre 18-22 % caña como seviene haciendo históricamente, lo que permitió lograr un ahorro de agua de 66670,1 t, esto haceque se ahorren 9531.77 kWh de energía eléctrica por bombeo, permitiendo un efecto económicototal entre 22939,92 – 218505,47 USD.Palabras claves: imbibición, ingenios azucareros, energía______________________________________________________________AbstractA study was performed of the use of the water of imbibition in the industry of the sugar cane ofCuba and internationally. More than 200 bibliographical sources were reviewed reaching importantconclusions as far as the amount and temperature from the imbibition water, as well as the schemeused of imbibition water most commonly used.A very simple procedure is obtained to determine the optimal amount of imbibition waterconsidering the updated prices of the sugar and the bagasse as fuel and for other uses. It is appliedfor his validation in two sugar companies of the province of Cienfuegos. In the present economicconditions the results showed that it is advisable to use an amount of imbibition water between10.4 -15,4 % of the amount of cane processed based on the use of the bagasse and not between18-22% as it

  8. Aqueous pathways dominate permeation of solutes across Pisum sativum seed coats and mediate solute transport via diffusion and bulk flow of water.

    Science.gov (United States)

    Niemann, Sylvia; Burghardt, Markus; Popp, Christian; Riederer, Markus

    2013-05-01

    The permeability of seed coats to solutes either of biological or anthropogenic origin plays a major role in germination, seedling growth and seed treatment by pesticides. An experimental set-up was designed for investigating the mechanisms of seed coat permeation, which allows steady-state experiments with isolated seed coats of Pisum sativum. Permeances were measured for a set of organic model compounds with different physicochemical properties and sizes. The results show that narrow aqueous pathways dominate the diffusion of solutes across pea seed coats, as indicated by a correlation of permeances with the molecular sizes of the compounds instead of their lipophilicity. Further indicators for an aqueous pathway are small size selectivity and a small effect of temperature on permeation. The application of an osmotic water potential gradient across isolated seed coats leads to an increase in solute transfer, indicating that the aqueous pathways form a water-filled continuum across the seed coat allowing the bulk flow of water. Thus, the uptake of organic solutes across pea testae has two components: (1) by diffusion and (2) by bulk water inflow, which, however, is relevant only during imbibition. © 2012 Blackwell Publishing Ltd.

  9. Understanding the role of H(2)O(2) during pea seed germination: a combined proteomic and hormone profiling approach.

    Science.gov (United States)

    Barba-Espín, Gregorio; Diaz-Vivancos, Pedro; Job, Dominique; Belghazi, Maya; Job, Claudette; Hernández, José Antonio

    2011-11-01

    In a previous publication, we showed that the treatment of pea seeds in the presence of hydrogen peroxide (H(2)O(2)) increased germination performance as well as seedling growth. To gain insight into the mechanisms responsible for this behaviour, we have analysed the effect of treating mature pea seeds in the presence of 20 mm H(2)O(2) on several oxidative features such as protein carbonylation, endogenous H(2)O(2) and lipid peroxidation levels. We report that H(2)O(2) treatment of the pea seeds increased their endogenous H(2)O(2) content and caused carbonylation of storage proteins and of several metabolic enzymes. Under the same conditions, we also monitored the expression of two MAPK genes known to be activated by H(2)O(2) in adult pea plants. The expression of one of them, PsMAPK2, largely increased upon pea seed imbibition in H(2)O(2) , whereas no change could be observed in expression of the other, PsMAPK3. The levels of several phytohormones such as 1-aminocyclopropane carboxylic acid, indole-3-acetic acid and zeatin appeared to correlate with the measured oxidative indicators and with the expression of PsMAPK2. Globally, our results suggest a key role of H(2)O(2) in the coordination of pea seed germination, acting as a priming factor that involves specific changes at the proteome, transcriptome and hormonal levels. © 2011 Blackwell Publishing Ltd.

  10. Approximation by planar elastic curves

    DEFF Research Database (Denmark)

    Brander, David; Gravesen, Jens; Nørbjerg, Toke Bjerge

    2016-01-01

    We give an algorithm for approximating a given plane curve segment by a planar elastic curve. The method depends on an analytic representation of the space of elastic curve segments, together with a geometric method for obtaining a good initial guess for the approximating curve. A gradient......-driven optimization is then used to find the approximating elastic curve....

  11. Power Curve Measurements REWS

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here, the refere......This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here......, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...

  12. Benefit and cost curves for typical pollination mutualisms.

    Science.gov (United States)

    Morris, William F; Vázquez, Diego P; Chacoff, Natacha P

    2010-05-01

    Mutualisms provide benefits to interacting species, but they also involve costs. If costs come to exceed benefits as population density or the frequency of encounters between species increases, the interaction will no longer be mutualistic. Thus curves that represent benefits and costs as functions of interaction frequency are important tools for predicting when a mutualism will tip over into antagonism. Currently, most of what we know about benefit and cost curves in pollination mutualisms comes from highly specialized pollinating seed-consumer mutualisms, such as the yucca moth-yucca interaction. There, benefits to female reproduction saturate as the number of visits to a flower increases (because the amount of pollen needed to fertilize all the flower's ovules is finite), but costs continue to increase (because pollinator offspring consume developing seeds), leading to a peak in seed production at an intermediate number of visits. But for most plant-pollinator mutualisms, costs to the plant are more subtle than consumption of seeds, and how such costs scale with interaction frequency remains largely unknown. Here, we present reasonable benefit and cost curves that are appropriate for typical pollinator-plant interactions, and we show how they can result in a wide diversity of relationships between net benefit (benefit minus cost) and interaction frequency. We then use maximum-likelihood methods to fit net-benefit curves to measures of female reproductive success for three typical pollination mutualisms from two continents, and for each system we chose the most parsimonious model using information-criterion statistics. We discuss the implications of the shape of the net-benefit curve for the ecology and evolution of plant-pollinator mutualisms, as well as the challenges that lie ahead for disentangling the underlying benefit and cost curves for typical pollination mutualisms.

  13. Curved electromagnetic missiles

    International Nuclear Information System (INIS)

    Myers, J.M.; Shen, H.M.; Wu, T.T.

    1989-01-01

    Transient electromagnetic fields can exhibit interesting behavior in the limit of great distances from their sources. In situations of finite total radiated energy, the energy reaching a distant receiver can decrease with distance much more slowly than the usual r - 2 . Cases of such slow decrease have been referred to as electromagnetic missiles. All of the wide variety of known missiles propagate in essentially straight lines. A sketch is presented here of a missile that can follow a path that is strongly curved. An example of a curved electromagnetic missile is explicitly constructed and some of its properties are discussed. References to details available elsewhere are given

  14. Algebraic curves and cryptography

    CERN Document Server

    Murty, V Kumar

    2010-01-01

    It is by now a well-known paradigm that public-key cryptosystems can be built using finite Abelian groups and that algebraic geometry provides a supply of such groups through Abelian varieties over finite fields. Of special interest are the Abelian varieties that are Jacobians of algebraic curves. All of the articles in this volume are centered on the theme of point counting and explicit arithmetic on the Jacobians of curves over finite fields. The topics covered include Schoof's \\ell-adic point counting algorithm, the p-adic algorithms of Kedlaya and Denef-Vercauteren, explicit arithmetic on

  15. IGMtransmission: Transmission curve computation

    Science.gov (United States)

    Harrison, Christopher M.; Meiksin, Avery; Stock, David

    2015-04-01

    IGMtransmission is a Java graphical user interface that implements Monte Carlo simulations to compute the corrections to colors of high-redshift galaxies due to intergalactic attenuation based on current models of the Intergalactic Medium. The effects of absorption due to neutral hydrogen are considered, with particular attention to the stochastic effects of Lyman Limit Systems. Attenuation curves are produced, as well as colors for a wide range of filter responses and model galaxy spectra. Photometric filters are included for the Hubble Space Telescope, the Keck telescope, the Mt. Palomar 200-inch, the SUBARU telescope and UKIRT; alternative filter response curves and spectra may be readily uploaded.

  16. What Are Chia Seeds?

    Science.gov (United States)

    ... your diet? Chia seeds come from the desert plant Salvia hispanica , a member of the mint family. ... ancient Aztec diet. The seeds of a related plant, Salvia columbariae (golden chia), were used primarily by ...

  17. Seeds and Synergies

    International Development Research Centre (IDRC) Digital Library (Canada)

    'Seeds and Synergies presents inspiring evidence of change in practice and policy ... Seeds of inspiration: breathing new life into the formal agricultural research .... and Urban Development and Poverty Alleviation and Agricultural Commodity ...

  18. Seeds as biosocial commons

    NARCIS (Netherlands)

    Patnaik, Archana

    2016-01-01

    This research investigates and describes the conservation and use of Plant Genetic Resources (PGRs), especially seeds through processes of commonisation. Seeds form an important element for sustaining human life (through food production) and social relations (by maintaining agricultural

  19. Seed dispersal in fens

    NARCIS (Netherlands)

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and

  20. Learning from uncertain curves

    DEFF Research Database (Denmark)

    Mallasto, Anton; Feragen, Aasa

    2017-01-01

    We introduce a novel framework for statistical analysis of populations of nondegenerate Gaussian processes (GPs), which are natural representations of uncertain curves. This allows inherent variation or uncertainty in function-valued data to be properly incorporated in the population analysis. Us...

  1. Power Curve Measurements

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  2. Power Curve Measurements, FGW

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....

  3. Power Curve Measurements

    DEFF Research Database (Denmark)

    Federici, Paolo; Vesth, Allan

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....

  4. Power Curve Measurements

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine...

  5. Carbon Lorenz Curves

    NARCIS (Netherlands)

    Groot, L.F.M.|info:eu-repo/dai/nl/073642398

    2008-01-01

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across

  6. The Axial Curve Rotator.

    Science.gov (United States)

    Hunter, Walter M.

    This document contains detailed directions for constructing a device that mechanically produces the three-dimensional shape resulting from the rotation of any algebraic line or curve around either axis on the coordinate plant. The device was developed in response to student difficulty in visualizing, and thus grasping the mathematical principles…

  7. Nacelle lidar power curve

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  8. Power curve report

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  9. Textbook Factor Demand Curves.

    Science.gov (United States)

    Davis, Joe C.

    1994-01-01

    Maintains that teachers and textbook graphics follow the same basic pattern in illustrating changes in demand curves when product prices increase. Asserts that the use of computer graphics will enable teachers to be more precise in their graphic presentation of price elasticity. (CFR)

  10. ECM using Edwards curves

    NARCIS (Netherlands)

    Bernstein, D.J.; Birkner, P.; Lange, T.; Peters, C.P.

    2013-01-01

    This paper introduces EECM-MPFQ, a fast implementation of the elliptic-curve method of factoring integers. EECM-MPFQ uses fewer modular multiplications than the well-known GMP-ECM software, takes less time than GMP-ECM, and finds more primes than GMP-ECM. The main improvements above the

  11. Power Curve Measurements FGW

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine...

  12. Seed development and carbohydrates

    NARCIS (Netherlands)

    Wittich, P.E.

    1998-01-01

    Seeds assure the plant the onset of a next generation and a way of dispersal. They consist of endosperm and an embryo (originating from gametophytic tissue), enveloped by a seed coat (sporophytic tissue). Plants generate different types of seeds. For instance, the endosperm may either be

  13. The Effect of Seed Priming and Accelerated Aging on Germination and Physiochemical Changes in Milk Thistle (Silybum marianum

    Directory of Open Access Journals (Sweden)

    Ghasem PARMOON

    2013-05-01

    Full Text Available Effects of seed priming and aging on some physiological characteristics of Milk thistle was studied in a factoral experiment based on Complete Randomized Design (CRD. Tratments were included hydro priming (using distilled water, halo priming (0, 1.5, 3, 4.5 and 6% KNO3 and accelerated aging (0, 2, 4 and 6 days under 45°C and 95% humidity in three replications. Determined parameters were germination charactristics including germination percentage, daily germination speed, mean time of germination, seed vigor index, hypocutile length and hypocutile dry weight. Activity of catalase, peroxidase and polyphenol oxidase were determined at 12 hours after imbibition and seedling stage. According to results of this experiment, germination percentage, seed vigor and seedling growth of seeds were increased under all priming treatments. Improving the catalase and peroxidase activity led to decrease the aging damages. Germination characteristics were improved under both priming treatments at the beginning of germination as well as seedling growth. Polyphenol oxidase activity was increased in the pre-treated seeds but decreased in seedling growth stage. Aging treatments led to reduce the germination percentage, daily germination speed, seed vigor and seedling growth while the germination time was increased. Accelerated aging caused to reduce the germination rate and seedling growth of milk thistle that is probably due to increasing the lipid peroxidation, free radical increment and decreasing the antioxidants activity. The greatest and lowest antioxidants activity, the germination percentage, germination speed and seed vigor were respectively observed under priming using 3% KNO3 concentration and control seeds.

  14. Vacuolar biogenesis and aquaporin expression at early germination of broad bean seeds.

    Science.gov (United States)

    Novikova, Galina V; Tournaire-Roux, Colette; Sinkevich, Irina A; Lityagina, Snejana V; Maurel, Christophe; Obroucheva, Natalie

    2014-09-01

    A key event in seed germination is water uptake-mediated growth initiation in embryonic axes. Vicia faba var. minor (broad bean) seeds were used for studying cell growth, vacuolar biogenesis, expression and function of tonoplast water channel proteins (aquaporins) in embryonic axes during seed imbibition, radicle emergence and growth. Hypocotyl and radicle basal cells showed vacuole restoration from protein storage vacuoles, whereas de novo vacuole formation from provacuoles was observed in cells newly produced by root meristem. cDNA fragments of seven novel aquaporin isoforms including five Tonoplast Intrinsic Proteins (TIP) from three sub-types were amplified by PCR. The expression was probed using q-RT-PCR and when possible with isoform-specific antibodies. Decreased expression of TIP3s was associated to the transformation of protein storage vacuoles to vacuoles, whereas enhanced expression of a TIP2 homologue was closely linked to the fast cell elongation. Water channel functioning checked by inhibitory test with mercuric chloride showed closed water channels prior to growth initiation and active water transport into elongating cells. The data point to a crucial role of tonoplast aquaporins during germination, especially during growth of embryonic axes, due to accelerated water uptake and vacuole enlargement resulting in rapid cell elongation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  15. Codes and curves

    CERN Document Server

    Walker, Judy L

    2000-01-01

    When information is transmitted, errors are likely to occur. Coding theory examines efficient ways of packaging data so that these errors can be detected, or even corrected. The traditional tools of coding theory have come from combinatorics and group theory. Lately, however, coding theorists have added techniques from algebraic geometry to their toolboxes. In particular, by re-interpreting the Reed-Solomon codes, one can see how to define new codes based on divisors on algebraic curves. For instance, using modular curves over finite fields, Tsfasman, Vladut, and Zink showed that one can define a sequence of codes with asymptotically better parameters than any previously known codes. This monograph is based on a series of lectures the author gave as part of the IAS/PCMI program on arithmetic algebraic geometry. Here, the reader is introduced to the exciting field of algebraic geometric coding theory. Presenting the material in the same conversational tone of the lectures, the author covers linear codes, inclu...

  16. Carbon Lorenz Curves

    Energy Technology Data Exchange (ETDEWEB)

    Groot, L. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)

    2008-11-15

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across countries. These tools allow policy-makers and the general public to grasp at a single glance the impact of conventional distribution rules such as equal caps or grandfathering, or more sophisticated ones, on the distribution of greenhouse gas emissions. Second, using the Samuelson rule for the optimal provision of a public good, the Pareto-optimal distribution of carbon emissions is compared with the distribution that follows if countries follow Nash-Cournot abatement strategies. It is shown that the Pareto-optimal distribution under the Samuelson rule can be approximated by the equal cap division, represented by the diagonal in the Lorenz curve diagram.

  17. Dynamics of curved fronts

    CERN Document Server

    Pelce, Pierre

    1989-01-01

    In recent years, much progress has been made in the understanding of interface dynamics of various systems: hydrodynamics, crystal growth, chemical reactions, and combustion. Dynamics of Curved Fronts is an important contribution to this field and will be an indispensable reference work for researchers and graduate students in physics, applied mathematics, and chemical engineering. The book consist of a 100 page introduction by the editor and 33 seminal articles from various disciplines.

  18. International Wage Curves

    OpenAIRE

    David G. Blanchflower; Andrew J. Oswald

    1992-01-01

    The paper provides evidence for the existence of a negatively sloped locus linking the level of pay to the rate of regional (or industry) unemployment. This "wage curve" is estimated using microeconomic data for Britain, the US, Canada, Korea, Austria, Italy, Holland, Switzerland, Norway, and Germany, The average unemployment elasticity of pay is approximately -0.1. The paper sets out a multi-region efficiency wage model and argues that its predictions are consistent with the data.

  19. Anatomical curve identification

    Science.gov (United States)

    Bowman, Adrian W.; Katina, Stanislav; Smith, Joanna; Brown, Denise

    2015-01-01

    Methods for capturing images in three dimensions are now widely available, with stereo-photogrammetry and laser scanning being two common approaches. In anatomical studies, a number of landmarks are usually identified manually from each of these images and these form the basis of subsequent statistical analysis. However, landmarks express only a very small proportion of the information available from the images. Anatomically defined curves have the advantage of providing a much richer expression of shape. This is explored in the context of identifying the boundary of breasts from an image of the female torso and the boundary of the lips from a facial image. The curves of interest are characterised by ridges or valleys. Key issues in estimation are the ability to navigate across the anatomical surface in three-dimensions, the ability to recognise the relevant boundary and the need to assess the evidence for the presence of the surface feature of interest. The first issue is addressed by the use of principal curves, as an extension of principal components, the second by suitable assessment of curvature and the third by change-point detection. P-spline smoothing is used as an integral part of the methods but adaptations are made to the specific anatomical features of interest. After estimation of the boundary curves, the intermediate surfaces of the anatomical feature of interest can be characterised by surface interpolation. This allows shape variation to be explored using standard methods such as principal components. These tools are applied to a collection of images of women where one breast has been reconstructed after mastectomy and where interest lies in shape differences between the reconstructed and unreconstructed breasts. They are also applied to a collection of lip images where possible differences in shape between males and females are of interest. PMID:26041943

  20. Estimating Corporate Yield Curves

    OpenAIRE

    Antionio Diaz; Frank Skinner

    2001-01-01

    This paper represents the first study of retail deposit spreads of UK financial institutions using stochastic interest rate modelling and the market comparable approach. By replicating quoted fixed deposit rates using the Black Derman and Toy (1990) stochastic interest rate model, we find that the spread between fixed and variable rates of interest can be modeled (and priced) using an interest rate swap analogy. We also find that we can estimate an individual bank deposit yield curve as a spr...

  1. LCC: Light Curves Classifier

    Science.gov (United States)

    Vo, Martin

    2017-08-01

    Light Curves Classifier uses data mining and machine learning to obtain and classify desired objects. This task can be accomplished by attributes of light curves or any time series, including shapes, histograms, or variograms, or by other available information about the inspected objects, such as color indices, temperatures, and abundances. After specifying features which describe the objects to be searched, the software trains on a given training sample, and can then be used for unsupervised clustering for visualizing the natural separation of the sample. The package can be also used for automatic tuning parameters of used methods (for example, number of hidden neurons or binning ratio). Trained classifiers can be used for filtering outputs from astronomical databases or data stored locally. The Light Curve Classifier can also be used for simple downloading of light curves and all available information of queried stars. It natively can connect to OgleII, OgleIII, ASAS, CoRoT, Kepler, Catalina and MACHO, and new connectors or descriptors can be implemented. In addition to direct usage of the package and command line UI, the program can be used through a web interface. Users can create jobs for ”training” methods on given objects, querying databases and filtering outputs by trained filters. Preimplemented descriptors, classifier and connectors can be picked by simple clicks and their parameters can be tuned by giving ranges of these values. All combinations are then calculated and the best one is used for creating the filter. Natural separation of the data can be visualized by unsupervised clustering.

  2. After-ripening induced transcriptional changes of hormonal genes in wheat seeds: the cases of brassinosteroids, ethylene, cytokinin and salicylic acid.

    Directory of Open Access Journals (Sweden)

    Vijaya R Chitnis

    Full Text Available Maintenance and release of seed dormancy is regulated by plant hormones; their levels and seed sensitivity being the critical factors. This study reports transcriptional regulation of brassinosteroids (BR, ethylene (ET, cytokinin (CK and salicylic acid (SA related wheat genes by after-ripening, a period of dry storage that decays dormancy. Changes in the expression of hormonal genes due to seed after-ripening did not occur in the anhydrobiotic state but rather in the hydrated state. After-ripening induced dormancy decay appears to be associated with imbibition mediated increase in the synthesis and signalling of BR, via transcriptional activation of de-etiolated2, dwarf4 and brassinosteroid signaling kinase, and repression of brassinosteroid insensitive 2. Our analysis is also suggestive of the significance of increased ET production, as reflected by enhanced transcription of 1-aminocyclopropane-1-carboxylic acid oxidase in after-ripened seeds, and tight regulation of seed response to ET in regulating dormancy decay. Differential transcriptions of lonely guy, zeatin O-glucosyltransferases and cytokinin oxidases, and pseudo-response regulator between dormant and after-ripened seeds implicate CK in the regulation of seed dormancy in wheat. Our analysis also reflects the association of dormancy decay in wheat with seed SA level and NPR independent SA signaling that appear to be regulated transcriptionally by phenylalanine ammonia lyase, and whirly and suppressor of npr1 inducible1 genes, respectively. Co-expression clustering of the hormonal genes implies the significance of synergistic and antagonistic interaction between the different plant hormones in regulating wheat seed dormancy. These results contribute to further our understanding of the molecular features controlling seed dormancy in wheat.

  3. A direct method for determining complete positive and negative capillary pressure curves for reservoir rock using the centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Spinler, E.A.; Baldwin, B.A. [Phillips Petroleum Co., Bartlesville, OK (United States)

    1997-08-01

    A method is being developed for direct experimental determination of capillary pressure curves from saturation distributions produced during centrifuging fluids in a rock plug. A free water level is positioned along the length of the plugs to enable simultaneous determination of both positive and negative capillary pressures. Octadecane as the oil phase is solidified by temperature reduction while centrifuging to prevent fluid redistribution upon removal from the centrifuge. The water saturation is then measured via magnetic resonance imaging. The saturation profile within the plug and the calculation of pressures for each point of the saturation profile allows for a complete capillary pressure curve to be determined from one experiment. Centrifuging under oil with a free water level into a 100 percent water saturated plug results in the development of a primary drainage capillary pressure curve. Centrifuging similarly at an initial water saturation in the plug results in the development of an imbibition capillary pressure curve. Examples of these measurements are presented for Berea sandstone and chalk rocks.

  4. Hot seeding using large Y-123 seeds

    International Nuclear Information System (INIS)

    Scruggs, S J; Putman, P T; Zhou, Y X; Fang, H; Salama, K

    2006-01-01

    There are several motivations for increasing the diameter of melt textured single domain discs. The maximum magnetic field produced by a trapped field magnet is proportional to the radius of the sample. Furthermore, the availability of trapped field magnets with large diameter could enable their use in applications that have traditionally been considered to require wound electromagnets, such as beam bending magnets for particle accelerators and electric propulsion. We have investigated the possibility of using large area epitaxial growth instead of the conventional point nucleation growth mechanism. This process involves the use of large Y123 seeds for the purpose of increasing the maximum achievable Y123 single domain size. The hot seeding technique using large Y-123 seeds was employed to seed Y-123 samples. Trapped field measurements indicate that single domain samples were indeed grown by this technique. Microstructural evaluation indicates that growth can be characterized by a rapid nucleation followed by the usual peritectic grain growth which occurs when large seeds are used. Critical temperature measurements show that no local T c suppression occurs in the vicinity of the seed. This work supports the suggestion of using an iterative method for increasing the size of Y-123 single domains that can be grown

  5. Oil palm seed distribution

    Directory of Open Access Journals (Sweden)

    Durand-Gasselin Tristan

    2005-03-01

    Full Text Available For a tropical plant, the oil palm commodity chain has the peculiarity of possessing a major seed production sector for reasons that are primarily genetic. This seed sector has numerous original aspects. Breeders are also propagators and usually also distribute their seeds. Oil palm seeds are semi-recalcitrant: they display pseudo-dormancy. Achieving seed germination is difficult and requires lengthy treatments and special installations. This restriction greatly influences seed distribution and the role of the different stakeholders in the commodity chain. It was only once it had been discovered how the “sh” gene functioned, which controls shell thickness, and when it became necessary to produce “tenera” seeds derived from exclusively “dura x pisifera” crosses, that a true seed market developed. In addition it is difficult to organize seed distribution to smallholders. This is partly due to difficulties that the profession, or a State-run organization, has in controlling middlemen networks, and partly to the absence of any protective systems (UPOV, plant breeder certificate, etc. that generally oblige breeders to preserve and propagate parents in their own installations. In fact there are major inequalities in the access to seeds between agroindustry and smallholders. Another peculiarity of the oil palm seed market is the virtually total absence of guarantees for buyers: the quality of the research conducted by breeders, the seed production strategies necessary for transferring genetic progress, and the technical quality of production. The only guarantee today comes from the relations of confidence established year after year between breeders/distributors and growers. In this fields, research can lead to some proposals: molecular biology offers some interesting prospects for certifying seed quality and social science develop effective communication methods.

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

    Science.gov (United States)

    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.

  7. Uniformization of elliptic curves

    OpenAIRE

    Ülkem, Özge; Ulkem, Ozge

    2015-01-01

    Every elliptic curve E defined over C is analytically isomorphic to C*=qZ for some q ∊ C*. Similarly, Tate has shown that if E is defined over a p-adic field K, then E is analytically isomorphic to K*=qZ for some q ∊ K . Further the isomorphism E(K) ≅ K*/qZ respects the action of the Galois group GK/K, where K is the algebraic closure of K. I will explain the construction of this isomorphism.

  8. Peanut Seed Vigor Evaluation Using a Thermal Gradient

    Directory of Open Access Journals (Sweden)

    Timothy L. Grey

    2011-01-01

    Full Text Available Experiments conducted from 2007 to 2009 evaluated germination of 11 peanut runner-type cultivars. Germination was evaluated in Petridishes incubated over a thermal gradient ranging from 14 to 30°C at 1.0 C increments. Beginning 24 hr after seeding, peanut was counted as germinated when radicles were greater than 5 mm long, with removal each day. Germination was counted daily for seven days after seeding. Growing-degree day (GDD accumulation for each temperature increment was calculated based on daily mean temperature for that Petri dish. Two indices were obtained from a logistic growth curve used to elucidate seed germination by cultivar: (1 maximum indices of germination and (2 GDD value at 80% germination (Germ80, an indication of seed vigor the lower the Germ80 value, the greater the seed lot vigor. Based on the two indices, seed lots “AT 3081R”, “AP-3”, “GA-06G”, and “Carver” had the strongest seed vigor (Germ80 26 to 47 GDD and a high maximum incidence of germination rate (80 to 94%. Seed lots of “C99-R”, “Georgia-01R”, “Georgia-02C”, and “Georgia-03L” had inconsistent seed performance, failing to achieve 80% germination in at least two of three years.

  9. Does the informal seed system threaten cowpea seed health?

    NARCIS (Netherlands)

    Biemond, P.C.; Oguntade, O.; Lava Kumar, P.; Stomph, T.J.; Termorshuizen, A.J.; Struik, P.C.

    2013-01-01

    Most smallholder farmers in developing countries depend on an informal Seed System (SS) for their seed. The informal SS is often criticized because farmer-produced seed samples are not tested for seed health, thus accepting the risk of planting infected seeds. Here we aimed at assessing the quality

  10. Roc curves for continuous data

    CERN Document Server

    Krzanowski, Wojtek J

    2009-01-01

    Since ROC curves have become ubiquitous in many application areas, the various advances have been scattered across disparate articles and texts. ROC Curves for Continuous Data is the first book solely devoted to the subject, bringing together all the relevant material to provide a clear understanding of how to analyze ROC curves.The fundamental theory of ROC curvesThe book first discusses the relationship between the ROC curve and numerous performance measures and then extends the theory into practice by describing how ROC curves are estimated. Further building on the theory, the authors prese

  11. The effects of free amino acids profiles on seeds germination/dormancy and seedlings development of two genetically different cultivars of Yemeni Pomegranates

    Directory of Open Access Journals (Sweden)

    Alhadi Fatima A.

    2012-04-01

    seeds germination in plant, therefore Khazemi germination capacity was assumed to be regulated more or less by these AAs. In addition, changes in amino acid composition in the germinated Khazemi cultivar during various stages of seeds germination including imbibition, germination, and sprouts stages have been noticed to change in response with germination demands. This suggests that amino acids reserves in dry seeds are major determinant for germination capacity and germination behavior in the following steps of germination. The noticed particular AAs increase/decrease along the time course of Khazemi pomegranate germination till establishment of heterotrophic seedlings were used as cornerstones for elucidation and deduction of putative function and relevant biochemical pathways controlling initiation of seeds germination and seedlings developments. Based on publicly available databases of model plants and literatures surveys, we established correlations between prevailing AAs factors as biochemical parameters actively involved in seeds dormancy-breaking and germination process.

  12. combining high seed number and weight to improve seed yield

    African Journals Online (AJOL)

    ACSS

    ABSTRACT. Increasing seed size and seed weight is an important trait for trade, yield component and adaptation of chickpea ... determining yield or quality, and the development of rapid and ..... C.G. 1981. Control of seed growth in soybeans.

  13. Producing the target seed: Seed collection, treatment, and storage

    Science.gov (United States)

    Robert P. Karrfalt

    2011-01-01

    The role of high quality seeds in producing target seedlings is reviewed. Basic seed handling and upgrading techniques are summarized. Current advances in seed science and technology as well as those on the horizon are discussed.

  14. Curved Josephson junction

    International Nuclear Information System (INIS)

    Dobrowolski, Tomasz

    2012-01-01

    The constant curvature one and quasi-one dimensional Josephson junction is considered. On the base of Maxwell equations, the sine–Gordon equation that describes an influence of curvature on the kink motion was obtained. It is showed that the method of geometrical reduction of the sine–Gordon model from three to lower dimensional manifold leads to an identical form of the sine–Gordon equation. - Highlights: ► The research on dynamics of the phase in a curved Josephson junction is performed. ► The geometrical reduction is applied to the sine–Gordon model. ► The results of geometrical reduction and the fundamental research are compared.

  15. Curved-Duct

    Directory of Open Access Journals (Sweden)

    Je Hyun Baekt

    2000-01-01

    Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.

  16. Elliptic curves for applications (Tutorial)

    NARCIS (Netherlands)

    Lange, T.; Bernstein, D.J.; Chatterjee, S.

    2011-01-01

    More than 25 years ago, elliptic curves over finite fields were suggested as a group in which the Discrete Logarithm Problem (DLP) can be hard. Since then many researchers have scrutinized the security of the DLP on elliptic curves with the result that for suitably chosen curves only exponential

  17. Titration Curves: Fact and Fiction.

    Science.gov (United States)

    Chamberlain, John

    1997-01-01

    Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…

  18. Efficiency of alfalfa seed processing with different seed purity

    OpenAIRE

    Đokić, Dragoslav; Stanisavljević, Rade; Terzić, Dragan; Milenković, Jasmina; Radivojević, Gordana; Koprivica, Ranko; Štrbanović, Ratibor

    2015-01-01

    The work was carried out analysis of the impact of the initial purity of raw alfalfa seed on the resulting amount of processed seed in the processing. Alfalfa is very important perennial forage legume which is used for fodder and seed production. Alfalfa seed is possible to achieve high yields and very good financial effects. To obtain the seed material with good characteristics complex machines for cleaning and sorting seeds are used. In the processing center of the Institute for forage crop...

  19. Paper (essay on seed

    Directory of Open Access Journals (Sweden)

    Mirić Mladen

    2013-01-01

    Full Text Available Based on detailed studies of the past of the agrarian thought of the world (evolution of agro-innovation, and within it, the relationship of man and seed, the author has selected key data for Table 1. In addition, more or less known folk sayings, proverbs, curses and allegories in which the seed is the key word have been collected. Then, religious books, folk art and literature works (sayings of prominent individuals and experts and observations of the author himself have been studied. According to the collected opus, it can be concluded that the vast importance of seed meaningfully entwined into all spheres of folk life and cultural heritage. Seed is directly tied to the following eight key (revolutionary milestones in the food and economic life of mankind: 1. the first and for the longest time, the seed used to be the main food of the people and the first food reserve; 2. Neolithic Revolution was simply caused by the sowing of seeds; 3. for the sake of sowing man began to develop more complex processing techniques; 4. everywhere and forever, especially since the late 15th century, the seed has been a carrier of (rescuing plants between Europe and the New World, that is, between continents; 5. seed was the first product that has been chemically treated since the mid-18th century; 6. standard operation procedures and quality are promoted on seed by which it became the first product to have prescribed (compulsory methods, but it also became a good whose quality has to be tested before sale; 7. hybrid seed is a 'perpetrator' of the green revolution in the mid-20th century and at last there is disputable seed of genetically modified organisms that are spreading with certain reactions. The author proposes that the United Nations Standard International Trade Classification includes a special section (division which would classify the seed for sowing, while beyond this Classification terms such as seed, plant seed should be replaced with non-seed

  20. Seed dormancy and germination.

    Science.gov (United States)

    Penfield, Steven

    2017-09-11

    Reproduction is a critical time in plant life history. Therefore, genes affecting seed dormancy and germination are among those under strongest selection in natural plant populations. Germination terminates seed dispersal and thus influences the location and timing of plant growth. After seed shedding, germination can be prevented by a property known as seed dormancy. In practise, seeds are rarely either dormant or non-dormant, but seeds whose dormancy-inducing pathways are activated to higher levels will germinate in an ever-narrower range of environments. Thus, measurements of dormancy must always be accompanied by analysis of environmental contexts in which phenotypes or behaviours are described. At its simplest, dormancy can be imposed by the formation of a simple physical barrier around the seed through which gas exchange and the passage of water are prevented. Seeds featuring this so-called 'physical dormancy' often require either scarification or passage through an animal gut (replete with its associated digestive enzymes) to disrupt the barrier and permit germination. In other types of seeds with 'morphological dormancy' the embryo remains under-developed at maturity and a dormant phase exists as the embryo continues its growth post-shedding, eventually breaking through the surrounding tissues. By far, the majority of seeds exhibit 'physiological dormancy' - a quiescence program initiated by either the embryo or the surrounding endosperm tissues. Physiological dormancy uses germination-inhibiting hormones to prevent germination in the absence of the specific environmental triggers that promote germination. During and after germination, early seedling growth is supported by catabolism of stored reserves of protein, oil or starch accumulated during seed maturation. These reserves support cell expansion, chloroplast development and root growth until photoauxotrophic growth can be resumed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  1. Artificial Seeds and their Applications

    Indian Academy of Sciences (India)

    currently working on ... heterozygosity of seed, minute seed size, presence of reduced ... Advantages of Artificial or Synthetic Seeds over Somatic Embryos for Propagation .... hour gives optimum bead hardness and rigidity for the produc-.

  2. A Journey Between Two Curves

    Directory of Open Access Journals (Sweden)

    Sergey A. Cherkis

    2007-03-01

    Full Text Available A typical solution of an integrable system is described in terms of a holomorphic curve and a line bundle over it. The curve provides the action variables while the time evolution is a linear flow on the curve's Jacobian. Even though the system of Nahm equations is closely related to the Hitchin system, the curves appearing in these two cases have very different nature. The former can be described in terms of some classical scattering problem while the latter provides a solution to some Seiberg-Witten gauge theory. This note identifies the setup in which one can formulate the question of relating the two curves.

  3. Seed thioredoxin h

    DEFF Research Database (Denmark)

    Hägglund, Per; Finnie, Christine; Yano, Hiroyuki

    2016-01-01

    , for example chloroplastic f- and m-type thioredoxins involved in regulation of the Calvin-Benson cycle. The cytosolic h-type thioredoxins act as key regulators of seed germination and are recycled by NADPH-dependent thioredoxin reductase. The present review on thioredoxin h systems in plant seeds focuses...

  4. Saving Seed Microbiomes

    NARCIS (Netherlands)

    Berg, Gabriele; Raaijmakers, J.M.

    2018-01-01

    Plant seeds are home to diverse microbial communities whose composition is determined by plant genotype, environment, and management practices. Plant domestication is now recognized as an important driver of plant-associated microbial diversity. To what extent and how domestication affects seed

  5. Sugar apple (Annona squamosa L., Annonaceae seed germination: morphological and anatomical changes

    Directory of Open Access Journals (Sweden)

    Fabio Ernesto Martínez-Maldonado

    2013-08-01

    Full Text Available The anon or sugar apple is a species of the Annona genus, widely distributed in the world and in Colombia and a fruit with great potential in domestic and international markets. However, the technical information related to the aspects of propagation and production is limited. In the present study, the morphological and anatomical changes during seed germination of the sugar apple were determined using histological techniques and photographic records. The results show that seed germination is a process that takes place in two stages: testa rupture and endosperm rupture-radicle protrusion. In the post-germination stages, the induction and formation of lateral roots that were endogenously produced from the primary root from the pericycle were seen. The endosperm underwent morphological changes that increased its volume during imbibition and degraded in the final stages of germination, which could be indicative of endosperm weakening and reduction of mechanical strength imposed by embryo growth, which was required to complete germination in A. squamosa

  6. Soil Water Retention Curve

    Science.gov (United States)

    Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

    2016-12-01

    Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

  7. Iodine-125 thin seeds decrease prostate swelling during transperineal interstitial permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Beydoun, Nadine; Bucci, Joseph A.; Chin, Yaw S.; Malouf, David

    2014-01-01

    Prostate swelling following seed implantation is a well-recognised phenomenon. The purpose of this intervention was to assess whether using thinner seeds reduces post-implant swelling with permanent prostate brachytherapy. Eighteen consecutive patients eligible for prostate seed brachytherapy underwent seed implantation using iodine-125 (I-125) thin seeds. Operative time, dosimetry, prostate swelling and toxicity were assessed and compared with standard I-125 stranded seed controls, sourced from the department's brachytherapy database. A learning curve was noted with the thin seeds in terms of greater bending and deviation of needles from their intended path. This translated into significantly longer total operative time (88 vs 103 minutes; P=0.009, 95% confidence interval (CI) 4.1-24.3) and time per needle insertion (2.6 vs 3.7 minutes; P<0.001, 95% CI 0.5-1.3) for the thin seeds. Day 30 prostate volumes were significantly smaller in the thin seed group compared with standard seeds (40.9cc vs 46.8cc; P=0.001, 95% CI 1.5-5.6). The ratio of preoperative transrectal ultrasound to day 30 post-implant CT volume was also smaller in the thin seed group (1.2±0.1 for standard seeds vs 1.1±0.1 for thin seeds). Post-implant dosimetric parameters were comparable for both groups. No significant differences were seen in acute urinary morbidity or quality of life between the two groups. I-125 thin seeds are associated with an initial learning curve, with longer operative time, even for experienced brachytherapists. The significant reduction in day 30 prostate volumes with the thin seeds has useful implications in terms of optimising dose coverage to the prostate in the early period post-implantation, as well as improving the accuracy of post-implant dosimetric assessments.

  8. TIME REDUCTION FOR SURINAM GRASS SEED GERMINATION TEST

    Directory of Open Access Journals (Sweden)

    Camila de Aquino Tomaz

    2015-10-01

    Full Text Available ABSTRACTThe period for the germination test of Surinam grass seeds established by the Rules for Seeds Testing is 28 days, considered too lengthy by producers, venders, and seed analysis laboratories. So, the objective of this research was to evaluate the possibility of reducing the time for the germination test of Surinam grass seeds and to establish a method for dormancy breaking and the ideal temperature. Ten seed lots were submitted to the following treatments to overcome seed dormancy: control; substrate moistening with 0.2% KNO3; and scarification with sulfuric acid (98% 36 N for 15 minutes. After the treatments, the lots were submitted to seed water content, germination and tetrazolium tests. During the germination test, conducted with four replicates of 100 seeds per treatment for 28 days, two conditions of alternating temperatures (20-35 °C and 15-35 °C with 8 hours of light were tested. Attempting to determine the test end date, daily counts of the number of normal seedlings were made and for each lot, treatment, and temperature, a growth curve for the evaluation of germination was adjusted. The segmented regression model parameter estimations were calculated for each treatment. The germination test of Braquiaria decumbensseeds may be evaluated in 12 days after sowing using alternating temperatures of 20-35 °C and without any treatment to overcome dormancy.

  9. Fermions in curved spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Lippoldt, Stefan

    2016-01-21

    In this thesis we study a formulation of Dirac fermions in curved spacetime that respects general coordinate invariance as well as invariance under local spin base transformations. We emphasize the advantages of the spin base invariant formalism both from a conceptual as well as from a practical viewpoint. This suggests that local spin base invariance should be added to the list of (effective) properties of (quantum) gravity theories. We find support for this viewpoint by the explicit construction of a global realization of the Clifford algebra on a 2-sphere which is impossible in the spin-base non-invariant vielbein formalism. The natural variables for this formulation are spacetime-dependent Dirac matrices subject to the Clifford-algebra constraint. In particular, a coframe, i.e. vielbein field is not required. We disclose the hidden spin base invariance of the vielbein formalism. Explicit formulas for the spin connection as a function of the Dirac matrices are found. This connection consists of a canonical part that is completely fixed in terms of the Dirac matrices and a free part that can be interpreted as spin torsion. The common Lorentz symmetric gauge for the vielbein is constructed for the Dirac matrices, even for metrics which are not linearly connected. Under certain criteria, it constitutes the simplest possible gauge, demonstrating why this gauge is so useful. Using the spin base formulation for building a field theory of quantized gravity and matter fields, we show that it suffices to quantize the metric and the matter fields. This observation is of particular relevance for field theory approaches to quantum gravity, as it can serve for a purely metric-based quantization scheme for gravity even in the presence of fermions. Hence, in the second part of this thesis we critically examine the gauge, and the field-parametrization dependence of renormalization group flows in the vicinity of non-Gaussian fixed points in quantum gravity. While physical

  10. Systems biology and genome-wide approaches to unveil the molecular players involved in the pre-germinative metabolism: implications on seed technology traits.

    Science.gov (United States)

    Macovei, Anca; Pagano, Andrea; Leonetti, Paola; Carbonera, Daniela; Balestrazzi, Alma; Araújo, Susana S

    2017-05-01

    The pre-germinative metabolism is among the most fascinating aspects of seed biology. The early seed germination phase, or pre-germination, is characterized by rapid water uptake (imbibition), which directs a series of dynamic biochemical events. Among those are enzyme activation, DNA damage and repair, and use of reserve storage compounds, such as lipids, carbohydrates and proteins. Industrial seedling production and intensive agricultural production systems require seed stocks with high rate of synchronized germination and low dormancy. Consequently, seed dormancy, a quantitative trait related to the activation of the pre-germinative metabolism, is probably the most studied seed trait in model species and crops. Single omics, systems biology, QTLs and GWAS mapping approaches have unveiled a list of molecules and regulatory mechanisms acting at transcriptional, post-transcriptional and post-translational levels. Most of the identified candidate genes encode for regulatory proteins targeting ROS, phytohormone and primary metabolisms, corroborating the data obtained from simple molecular biology approaches. Emerging evidences show that epigenetic regulation plays a crucial role in the regulation of these mentioned processes, constituting a still unexploited strategy to modulate seed traits. The present review will provide an up-date of the current knowledge on seed pre-germinative metabolism, gathering the most relevant results from physiological, genetics, and omics studies conducted in model and crop plants. The effects exerted by the biotic and abiotic stresses and priming are also addressed. The possible implications derived from the modulation of pre-germinative metabolism will be discussed from the point of view of seed quality and technology.

  11. High-Throughput Scoring of Seed Germination.

    Science.gov (United States)

    Ligterink, Wilco; Hilhorst, Henk W M

    2017-01-01

    High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very informative as it lacks information about start, rate, and uniformity of germination, which are highly indicative of such traits as dormancy, stress tolerance, and seed longevity. The calculation of cumulative germination curves requires information about germination percentage at various time points. We developed the GERMINATOR package: a simple, highly cost-efficient, and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The GERMINATOR package contains three modules: (I) design of experimental setup with various options to replicate and randomize samples; (II) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (III) curve fitting of cumulative germination data and the extraction, recap, and visualization of the various germination parameters. GERMINATOR is a freely available package that allows the monitoring and analysis of several thousands of germination tests, several times a day by a single person.

  12. Glioblastoma with spinal seeding

    International Nuclear Information System (INIS)

    Fakhrai, N.; Fazeny-Doerner, B.; Marosi, C.; Czech, T.; Diekmann, K.; Birner, P.; Hainfellner, J.A.; Prayer, D.

    2004-01-01

    Background: extracranial seeding of glioblastoma multiforme (GBM) is very rare and its development depends on several factors. This case report describes two patients suffering from GBM with spinal seeding. In both cases, the anatomic localization of the primary tumor close to the cerebrospinal fluid (CSF) was the main factor for spinal seeding. Case reports: two patients with GBM and spinal seeding are presented. After diagnosis of spinal seeding, both patients were highly symptomatic from their spinal lesions. Case 1 experienced severe pain requiring opiates, and case 2 had paresis of lower limbs as well as urinary retention/incontinence. Both patients were treated with spinal radiation therapy. Nevertheless, they died 3 months after diagnosis of spinal seeding. Results: in both patients the diagnosis of spinal seeding was made at the time of cranial recurrence. Both tumors showed close contact to the CSF initially. Even though the patients underwent intensive treatment, it was not possible to keep them in a symptom-free state. Conclusion: because of short survival periods, patients deserve optimal pain management and dedicated palliative care. (orig.)

  13. Glioblastoma with spinal seeding

    Energy Technology Data Exchange (ETDEWEB)

    Fakhrai, N.; Fazeny-Doerner, B.; Marosi, C. [Clinical Div. of Oncology, Dept. of Medicine I, Univ. of Vienna (Austria); Czech, T. [Dept. of Neurosurgery, Univ. of Vienna (Austria); Diekmann, K. [Dept. of Radiooncology, Univ. of Vienna (Austria); Birner, P.; Hainfellner, J.A. [Clinical Inst. for Neurology, Univ. of Vienna (Austria); Prayer, D. [Dept. of Neuroradiology, Univ. of Vienna (Austria)

    2004-07-01

    Background: extracranial seeding of glioblastoma multiforme (GBM) is very rare and its development depends on several factors. This case report describes two patients suffering from GBM with spinal seeding. In both cases, the anatomic localization of the primary tumor close to the cerebrospinal fluid (CSF) was the main factor for spinal seeding. Case reports: two patients with GBM and spinal seeding are presented. After diagnosis of spinal seeding, both patients were highly symptomatic from their spinal lesions. Case 1 experienced severe pain requiring opiates, and case 2 had paresis of lower limbs as well as urinary retention/incontinence. Both patients were treated with spinal radiation therapy. Nevertheless, they died 3 months after diagnosis of spinal seeding. Results: in both patients the diagnosis of spinal seeding was made at the time of cranial recurrence. Both tumors showed close contact to the CSF initially. Even though the patients underwent intensive treatment, it was not possible to keep them in a symptom-free state. Conclusion: because of short survival periods, patients deserve optimal pain management and dedicated palliative care. (orig.)

  14. Physalis peruviana seed storage

    Directory of Open Access Journals (Sweden)

    Cíntia L. M. de Souza

    2016-03-01

    Full Text Available ABSTRACT Physalis peruviana belongs to Solanaceae family and has a high nutritional and nutraceutical potential. The production is intended for fruit consumption and the propagation is mainly by seeds. This study aimed to evaluate the influence of priming on the kinetics of germination of P. peruviana seeds stored at different temperatures. The seeds were stored at 5 and 25 °C in a chamber saturated with zinc chloride solution and in liquid nitrogen (-196 °C. Every 4 months, the seeds were removed from storage for evaluation of germination and moisture content in the laboratory and emergence and development of seedlings in greenhouse. During the last evaluation at 16 months, the seeds under the same conditions were subjected to salt stress. The moisture content varied during the storage period, but was always higher for seeds kept at -196 ºC. These seeds kept high germination percentage in water until 16 months, regardless of the tested temperature; however, in salt solution the germination percentage was significantly reduced.

  15. The temperature effect of low-energy ion beam implantation on seed

    International Nuclear Information System (INIS)

    Chang Shenghe; Su Mingjie; Qin Guangyong; Wu Yuping; Zhao Haizhen

    2005-01-01

    The temperature effects of low-energy ion beam implantation on the seed germination were studied. Maize dry seeds were covered with copy paper, aluminum foil and without cover, respectively. Results showed that the germination rate of the seeds covered with paper which was the bad heat transmitter was the highest among three treatments, while that covered with aluminum foil which can transmit heat energy well was the least. The germination rate of the seeds covered with nothing was the second. Temperature affected seeds germination markedly. Generally the temperature of the target room inhibited the seeds' germination. After minus the effects of the temperature in the target room, the germination rates of the seeds were modified in this paper. The modified germination rate curve was also provided. (authors)

  16. Contrast of dry and water-saturated arabidopsis seeds irradiated by MeV energy ions

    International Nuclear Information System (INIS)

    Mei Tao; Qin Huaili; Xue Jianming; Wang Yugang

    2007-01-01

    The dry and water-saturated seeds of Arabidopsis thaliana were irradiated by H + ions with 6.5 MeV in atmosphere. The ion fluence used in this experiment was in the range of 4 x 10 9 -1 x 10 14 ions/cm 2 . According to the structure of the seed and TRIM simulation, the ions with the energy of 6.5 MeV can penetrate the whole seed. The experiment shows that the fluence-response curves for the dry seeds and water-saturated seeds had distinct shoulders and reduced rapidly. The experimental results show that the water-imbibed seeds were more sensitive than the dry seeds and the reason is from free radicals reaction. A model has been constructed, and primely simulates the experiment data. (authors)

  17. Effects of seed fermentation method on seed germination and vigor ...

    African Journals Online (AJOL)

    The present study was conducted to examine the influence of Lagenaria siceraria seed fermentation method on seed germination and vigor. Three seed fermentation methods (fermented in ambient air, plastic bag stored in ambient or in plastic bag buried) were tested on two cultivars during two years. Seed germination and ...

  18. Models of genus one curves

    OpenAIRE

    Sadek, Mohammad

    2010-01-01

    In this thesis we give insight into the minimisation problem of genus one curves defined by equations other than Weierstrass equations. We are interested in genus one curves given as double covers of P1, plane cubics, or complete intersections of two quadrics in P3. By minimising such a curve we mean making the invariants associated to its defining equations as small as possible using a suitable change of coordinates. We study the non-uniqueness of minimisations of the genus one curves des...

  19. MATHEMATICAL MODELING OF ORANGE SEED DRYING KINETICS

    Directory of Open Access Journals (Sweden)

    Daniele Penteado Rosa

    2015-06-01

    Full Text Available Drying of orange seeds representing waste products from juice processing was studied in the temperatures of 40, 50, 60 and 70 °C and drying velocities of 0.6, 1.0 and 1.4 m/s. Experimental drying kinetics of orange seeds were obtained using a convective air forced dryer. Three thin-layer models: Page model, Lewis model, and the Henderson-Pabis model and the diffusive model were used to predict the drying curves. The Henderson-Pabis and the diffusive models show the best fitting performance and statistical evaluations. Moreover, the temperature dependence on the effective diffusivity followed an Arrhenius relationship, and the activation energies ranging from 16.174 to 16.842 kJ/mol

  20. Prosopis Africana SEEDS (OKPEYE)

    African Journals Online (AJOL)

    User

    Keywords: Prosopis africana, okpeye seeds, thermal heat conductivity, specific heat capacity, thermal heat diffusivity, .... 2.3 Determination of Thermal Properties of Prosopis. Africana .... and the guard ring was filled with fiber glass at both the.

  1. Oil seed marketing prospects

    International Nuclear Information System (INIS)

    Ceroni, G.

    1992-01-01

    With its 100 million tonnes annual production, the American continent is by far the world's biggest producer of oil seed, followed by Asia - 52 million, and Europe - 27 million tonnes. The Italian and European Communities have the farming capacity to double their production, but international agreements currently prohibit such initiatives. After first providing a panorama of the world oil seed market, this paper discusses new reforms in European Communities internal agricultural policies which currently limit production. These reforms, intended to encourage the production of oil seed for use as an ecological automotive fuel alternative, call for an obligatory set-aside of 15% of producing farm-land in exchange for the compensatory removal of oil seed production limits

  2. Genetics and Forest Seed Handling

    DEFF Research Database (Denmark)

    Schmidt, Lars Holger

    2016-01-01

    High genetic quality seed is obtained from seed sources that match the planting site, have a good outcrossing rate, and are superior in some desirable characters. Non-degraded natural forests and plantations may be used as untested seed sources, which can sometimes be managed to promote outbreeding...... and increase seed production. Planted seed orchards aim at capturing large genetic variation and are planted in a design that facilitates genetic evaluation and promotes outbred seed production. Good seed production relies upon success of the whole range of reproductive events from flower differentiation...

  3. Seeds of impurity

    Directory of Open Access Journals (Sweden)

    Andrea Pavoni

    2015-06-01

    Full Text Available Ai Weiwei’s art installation Kui Hua Zi [Sunflower Seeds] took place between 2010 and 2011 in the gigantic Turbine Hall of the Tate Modern Gallery, in London. It consisted of 100 millions hand-crafted porcelain seeds made in Jingdezhen, China.1 An uneven surface to dive into, a haptic space of undulating vision, rustling steps, unusual horizontality, a meaningless quicksand where the separation between artwork and spectator is engulfed, the immunity of distant contemplation denied.

  4. Storage of sunflower seeds

    Directory of Open Access Journals (Sweden)

    Denise de Castro Lima

    Full Text Available The sunflower is among the top five crops in the world for the production of edible vegetable oil. The species displays rustic behavior, with an excellent edaphic and climatic adaptability index, being able to be cultivated throughout Brazil. Seed quality is the key to increasing production and productivity in the sunflower. The objective of this work was to monitor the viability of sunflower seeds with a view to their conservation when stored in different environments and packaging. The seeds were packed in paper bags, multilayered paper, black polyethylene and PET bottles; and stored for a period of twelve months in the following environments: dry cold room (10 ºC and 55% RH, the ambient conditions of Fortaleza, Ceará, Brazil (30-32 ºC and 75% RH, refrigerator (4 ºC and 38-43% RH and freezer (-20 ºC. Every three months, the water content of the seeds was determined and germination, accelerated ageing, speed of emergence index, and seedling dry weight were evaluated. The experimental design was completely randomized, in a scheme of split-lots, with four replications. It can be concluded that the natural environment is not suitable for the storage of sunflower seeds. Sunflower seeds remain viable for 12 months when stored in a dry cold room, refrigerator or freezer, irrespective of the type of packaging used.

  5. Seed dispersal in fens

    Science.gov (United States)

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  6. Quantum fields in curved space

    International Nuclear Information System (INIS)

    Birrell, N.D.; Davies, P.C.W.

    1982-01-01

    The book presents a comprehensive review of the subject of gravitational effects in quantum field theory. Quantum field theory in Minkowski space, quantum field theory in curved spacetime, flat spacetime examples, curved spacetime examples, stress-tensor renormalization, applications of renormalization techniques, quantum black holes and interacting fields are all discussed in detail. (U.K.)

  7. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice

    Science.gov (United States)

    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

  8. [Study on physiological and germination characteristics of Tulipa edulis seed].

    Science.gov (United States)

    Wu, Zhengjun; Zhu, Zaibiao; Guo, Qiaosheng; Ma, Hongliang; Xu, Hongjian; Miao, Yuanyuan

    2012-03-01

    Current study was conducted to investigate the seed physiological characteristics of Tulipa edulis and improve germination rate. Anatomical characteristics was observed. Seed water absorption curve was tested by soaking method. Dynamic of embryo development and germination rate as well as germination index under different conditions were recorded. And the biological test of cabbage seed was used for detecting the germination inhibitors. The embryo rate of newly matured seeds was about 10%, and there was no obstacle of water absorption on testa of T. edulis. The optimum method for embryo development was exposure to 300 mg x L(-1) gibberellin solution for 24 hours, and stratification at 25 degrees C for 70 days followed by stratification at 5 degrees C for 40 days. The germintion rate and germination index of dormancy-broken seeds under the dark environment at 10 degrees C and 15 degrees C were significantly higher than those under other conditions. Additionally, there were some germination inhibitory substances in dry seeds. The seed of T. edulis can be classified as having complex morphophysiological dormancy, and the morphological embryo dormancy played a leading role. Warm and cold stratification resulted in a fast dormancy breaking effect, and a high germination rate more than 90% could be obtained under the optimum conditions.

  9. Extended analysis of cooling curves

    International Nuclear Information System (INIS)

    Djurdjevic, M.B.; Kierkus, W.T.; Liliac, R.E.; Sokolowski, J.H.

    2002-01-01

    Thermal Analysis (TA) is the measurement of changes in a physical property of a material that is heated through a phase transformation temperature range. The temperature changes in the material are recorded as a function of the heating or cooling time in such a manner that allows for the detection of phase transformations. In order to increase accuracy, characteristic points on the cooling curve have been identified using the first derivative curve plotted versus time. In this paper, an alternative approach to the analysis of the cooling curve has been proposed. The first derivative curve has been plotted versus temperature and all characteristic points have been identified with the same accuracy achieved using the traditional method. The new cooling curve analysis also enables the Dendrite Coherency Point (DCP) to be detected using only one thermocouple. (author)

  10. Seed-borne pathogens and electrical conductivity of soybean seeds

    Directory of Open Access Journals (Sweden)

    Adriana Luiza Wain-Tassi

    2012-02-01

    Full Text Available Adequate procedures to evaluate seed vigor are important. Regarding the electrical conductivity test (EC, the interference in the test results caused by seed-borne pathogens has not been clarified. This research was carried out to study the influence of Phomopsis sojae (Leh. and Colletotrichum dematium (Pers. ex Fr. Grove var. truncata (Schw. Arx. fungi on EC results. Soybean seeds (Glycine max L. were inoculated with those fungi using potato, agar and dextrose (PDA medium with manitol (-1.0 MPa and incubated for 20 h at 25 °C. The colony diameter, index of mycelial growth, seed water content, occurrence of seed-borne pathogens, physiological potential of the seeds, measured by germination and vigor tests (seed germination index, cold test, accelerated aging and electrical conductivity, and seedling field emergence were determined. The contents of K+, Ca2+, and Mg2+ in the seed and in the soaking solution were also determined. A complete 2 × 4 factorial design with two seed sizes (5.5 and 6.5 mm and four treatments (control, seeds incubated without fungi, seeds incubated with Phomopsis and seeds incubated with Colletotrichum were used with eight (5.5 mm large seeds and six (6.5 mm large seeds replications. All seeds submitted to PDA medium had their germination reduced in comparison to the control seeds. This reduction was also observed when seed vigor and leached ions were considered. The presence of Phomopsis sojae fungus in soybean seed samples submitted to the EC test may be the cause of misleading results.

  11. The importance of using certified seed

    OpenAIRE

    Bogdanović Sandra; Mladenov Velimir; Balešević-Tubić Svetlana

    2015-01-01

    Certified seed is produced from the seed of known genetic origin and genetic purity with controlled and tested production, processed and declared in accordance with the Law on Seeds. Production of certified seed is carried out under the supervision of the Ministry of Agriculture and Environmental Protection, by seed producers formally listed in the Seed Register. Seed is processed in registered seed processing centres and quality is tested in laboratories accredited for seed testing. The orga...

  12. Computational aspects of algebraic curves

    CERN Document Server

    Shaska, Tanush

    2005-01-01

    The development of new computational techniques and better computing power has made it possible to attack some classical problems of algebraic geometry. The main goal of this book is to highlight such computational techniques related to algebraic curves. The area of research in algebraic curves is receiving more interest not only from the mathematics community, but also from engineers and computer scientists, because of the importance of algebraic curves in applications including cryptography, coding theory, error-correcting codes, digital imaging, computer vision, and many more.This book cove

  13. Molecular physiology of seeds

    International Nuclear Information System (INIS)

    Hajduch, M.

    2014-05-01

    Plant development is well described. However, full understanding of the regulation of processes associated with plant development is still missing. Present Dr.Sc. thesis advances our understanding of the regulation of plant development by quantitative proteomics analyses of seed development of soybean, canola, castor, flax, and model plant arabidopsis in control and environmentally challenged environments. The analysis of greenhouse-grown soybean, canola, castor, and arabidospis provided complex characterization of metabolic processes during seed development, for instance, of carbon assimilation into fatty acids. Furthermore, the analyses of soybean and flax grown in Chernobyl area provided in-depth characterization of seed development in radio-contaminated environment. Soybean and flax were altered by radio-contaminated environment in different way. However, these alterations resulted into modifications in seed oil content. Further analyses showed that soybean and flax possess alterations of carbon metabolism in cytoplasm and plastids along with increased activity of photosynthetic apparatus. Our present experiments are focused on further characterization of molecular bases that might be responsible for alterations of seed oil content in Chernobyl grown plants. (author)

  14. Effect of Seed Priming Treatments on Germination Traits of Two Mustard Cultivars (Brassica compestris var. parkland and Goldrash

    Directory of Open Access Journals (Sweden)

    M. Goldani

    2016-02-01

    Full Text Available Introduction: B. campestris is an old plant that commonly grows in arid and semi-arid areas. It has mucilage in the epidermal cells of canola seeds, a considerable variation in growth form and characteristics across the many cultivars. These species have in general, a flat root without an elongated crown, with stems that typically grow 30 to 120 cm tall. The leaves are large, soft, smooth or soft-hairy. The yellow flowers are small, usually less than 2 cm long (24. Seed priming is a procedure in which seed is soaked and then dried back to its original water content. Hydropriming uses only water in the process of controlled imbibitions, but osmopriming simply means soaking seeds in an osmotic solution. Seed priming is a technique of controlled hydration and drying that results in more rapid germination when the seed is reimbibed. Priming can be a valuable process for improving germination and uniformity of heterogeneously matured seed lots. Seed priming has been successfully demonstrated to improve germination and emergence in seeds of many crops, particularly vegetables and small seeded grasses. Seed priming is a presowing strategy for influencing seedling development by modulating pregermination metabolic activity prior to emergence of the radicle and generally enhances germination rate and plant performance. Fast germination and uniform emergence assist the farmer to “catch up” on the time lost to drought (17, 18. This research aimed to study the effect of the best treatments of osmopriming and hydropriming on varieties of mustard seed germination traits was conducted. Materials and Methods: The present research was conducted under laboratory conditions of the Ferdowsi University of Mashhad, Iran, during 2012 to determine the seed priming effects on germination traits of two cultivars of mustard. The experiment was in completely randomized design with six treatments. Seeds of two mustard cultivars including Goldrash and Parkland (Brassica

  15. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Science.gov (United States)

    2010-01-01

    ... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

  16. Seed research for improved technologies Pesquisa para o aprimoramento de tecnologia de sementes

    Directory of Open Access Journals (Sweden)

    R.J. Bino

    1998-01-01

    Full Text Available The production of high-quality seed is the basis for a durable a profitable agriculture. After production, seed is processed, conditioned, stored, shipped and germinated. For quality assurance, seed quality has to be controlled at all steps of the production chain. Seed functioning is accompanied by programmed transitions from cell proliferation to quiescence upon maturation and from quiescence to reinitiation of cellular metabolism upon imbibition. Despite the obvious importance of these control mechanisms, very little information is available at the molecular level concerning those elements that regulate seed germination. In the present study, the induction of cell cycle activity and the regulation of ß-tubulin expression is related to the water content and other physical properties of the seed.A produção de sementes de alta qualidade é a base para uma agricultura produtiva. Após a colheita, a semente é beneficiada, embalada, armazenada, transportada e semeada. Para maior segurança, tanto dos produtores como dos consumidores, a qualidade da semente deve ser mantida sob controle em todas as fases do processo de produção. O desempenho da semente é resultado de transições programadas desde a divisão celular até a quiescência, durante a maturação, e da quiescência até o reinicio do metabolismo celular, durante a embebição. Apesar da importância destes mecanismos de controle, há pouca informação disponível, a nível molecular, no que diz respeito aos elementos que regulam a germinação da semente. No presente trabalho, a indução do ciclo de atividade celular e a regulação da expressão de ß-tubulina são relacionadas ao grau de umidade e a outras propriedades físicas da semente.

  17. 51Cr - erythrocyte survival curves

    International Nuclear Information System (INIS)

    Paiva Costa, J. de.

    1982-07-01

    Sixteen patients were studied, being fifteen patients in hemolytic state, and a normal individual as a witness. The aim was to obtain better techniques for the analysis of the erythrocytes, survival curves, according to the recommendations of the International Committee of Hematology. It was used the radiochromatic method as a tracer. Previously a revisional study of the International Literature was made in its aspects inherent to the work in execution, rendering possible to establish comparisons and clarify phonomena observed in cur investigation. Several parameters were considered in this study, hindering both the exponential and the linear curves. The analysis of the survival curves of the erythrocytes in the studied group, revealed that the elution factor did not present a homogeneous answer quantitatively to all, though, the result of the analysis of these curves have been established, through listed programs in the electronic calculator. (Author) [pt

  18. Melting curves of gammairradiated DNA

    International Nuclear Information System (INIS)

    Hofer, H.; Altmann, H.; Kehrer, M.

    1978-08-01

    Melting curves of gammairradiated DNA and data derived of them, are reported. The diminished stability is explained by basedestruction. DNA denatures completely at room temperature, if at least every fifth basepair is broken or weakened by irradiation. (author)

  19. Management of the learning curve

    DEFF Research Database (Denmark)

    Pedersen, Peter-Christian; Slepniov, Dmitrij

    2016-01-01

    Purpose – This paper focuses on the management of the learning curve in overseas capacity expansions. The purpose of this paper is to unravel the direct as well as indirect influences on the learning curve and to advance the understanding of how these affect its management. Design...... the dimensions of the learning process involved in a capacity expansion project and identified the direct and indirect labour influences on the production learning curve. On this basis, the study proposes solutions to managing learning curves in overseas capacity expansions. Furthermore, the paper concludes...... with measures that have the potential to significantly reduce the non-value-added time when establishing new capacities overseas. Originality/value – The paper uses a longitudinal in-depth case study of a Danish wind turbine manufacturer and goes beyond a simplistic treatment of the lead time and learning...

  20. Growth curves for Laron syndrome.

    OpenAIRE

    Laron, Z; Lilos, P; Klinger, B

    1993-01-01

    Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls co...

  1. Flow over riblet curved surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, J B R; Freire, A P Silva, E-mail: atila@mecanica.ufrj.br [Mechanical Engineering Program, Federal University of Rio de Janeiro (COPPE/UFRJ), C.P. 68503, 21.941-972, Rio de Janeiro, RJ (Brazil)

    2011-12-22

    The present work studies the mechanics of turbulent drag reduction over curved surfaces by riblets. The effects of surface modification on flow separation over steep and smooth curved surfaces are investigated. Four types of two-dimensional surfaces are studied based on the morphometric parameters that describe the body of a blue whale. Local measurements of mean velocity and turbulence profiles are obtained through laser Doppler anemometry (LDA) and particle image velocimetry (PIV).

  2. Intersection numbers of spectral curves

    CERN Document Server

    Eynard, B.

    2011-01-01

    We compute the symplectic invariants of an arbitrary spectral curve with only 1 branchpoint in terms of integrals of characteristic classes in the moduli space of curves. Our formula associates to any spectral curve, a characteristic class, which is determined by the laplace transform of the spectral curve. This is a hint to the key role of Laplace transform in mirror symmetry. When the spectral curve is y=\\sqrt{x}, the formula gives Kontsevich--Witten intersection numbers, when the spectral curve is chosen to be the Lambert function \\exp{x}=y\\exp{-y}, the formula gives the ELSV formula for Hurwitz numbers, and when one chooses the mirror of C^3 with framing f, i.e. \\exp{-x}=\\exp{-yf}(1-\\exp{-y}), the formula gives the Marino-Vafa formula, i.e. the generating function of Gromov-Witten invariants of C^3. In some sense this formula generalizes ELSV, Marino-Vafa formula, and Mumford formula.

  3. Dissolution glow curve in LLD

    International Nuclear Information System (INIS)

    Haverkamp, U.; Wiezorek, C.; Poetter, R.

    1990-01-01

    Lyoluminescence dosimetry is based upon light emission during dissolution of previously irradiated dosimetric materials. The lyoluminescence signal is expressed in the dissolution glow curve. These curves begin, depending on the dissolution system, with a high peak followed by an exponentially decreasing intensity. System parameters that influence the graph of the dissolution glow curve, are, for example, injection speed, temperature and pH value of the solution and the design of the dissolution cell. The initial peak does not significantly correlate with the absorbed dose, it is mainly an effect of the injection. The decay of the curve consists of two exponential components: one fast and one slow. The components depend on the absorbed dose and the dosimetric materials used. In particular, the slow component correlates with the absorbed dose. In contrast to the fast component the argument of the exponential function of the slow component is independent of the dosimetric materials investigated: trehalose, glucose and mannitol. The maximum value, following the peak of the curve, and the integral light output are a measure of the absorbed dose. The reason for the different light outputs of various dosimetric materials after irradiation with the same dose is the differing solubility. The character of the dissolution glow curves is the same following irradiation with photons, electrons or neutrons. (author)

  4. Improving Soil Seed Bank Management.

    Science.gov (United States)

    Haring, Steven C; Flessner, Michael L

    2018-05-08

    Problems associated with simplified weed management motivate efforts for diversification. Integrated weed management uses fundamentals of weed biology and applied ecology to provide a framework for diversified weed management programs; the soil seed bank comprises a necessary part of this framework. By targeting seeds, growers can inhibit the propagule pressure on which annual weeds depend for agricultural invasion. Some current management practices affect weed seed banks, such as crop rotation and tillage, but these tools are often used without specific intention to manage weed seeds. Difficulties quantifying the weed seed bank, understanding seed bank phenology, and linking seed banks to emerged weed communities challenge existing soil seed bank management practices. Improved seed bank quantification methods could include DNA profiling of the soil seed bank, mark and recapture, or 3D LIDAR mapping. Successful and sustainable soil seed bank management must constrain functionally diverse and changing weed communities. Harvest weed seed controls represent a step forward, but over-reliance on this singular technique could make it short-lived. Researchers must explore tools inspired by other pest management disciplines, such as gene drives or habitat modification for predatory organisms. Future weed seed bank management will combine multiple complementary practices that enhance diverse agroecosystems. This article is protected by copyright. All rights reserved.

  5. Seeds of confusion : the impact of policies on seed systems

    OpenAIRE

    Louwaars, N.P.

    2007-01-01

    Seed is basic to crop production. Next to its importance in production, food security and rural development, seed is a key element in many debates about technology development and transfer, biodiversity, globalisation and equity. The sustainable availability of good quality seed is thus an important development issue. This study deals with the impact different types of regulation have on how farmers access seed. I have analysed current regulatory frameworks in terms of their impact on differe...

  6. Magnetic-seeding filtration

    International Nuclear Information System (INIS)

    Depaoli, D.

    1996-01-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes

  7. Study on the determination of coffea arabic radio sensibility curve

    International Nuclear Information System (INIS)

    Robleda, D.; Velazquez, R.

    1993-01-01

    The radiosensitivity curve of Coffea Arabic submitted to gamma irradiation from a 60C o source at the MRX-1500 with a dose power of 105 Gy/min was determined. For that study,. coffee seeds were irradiated at doses of 10,40,80 and 120 Gy, with a 40% of relative humidity; percentage of germination, height decrease, number and size of leaves, number and length of modes. As result of this analysis, GR50 and GR20 doses for searching genetic variability related to plant size reduction

  8. Distribution of some sequences of points on elliptic curves

    DEFF Research Database (Denmark)

    Lange, Tanja; Shparlinski, Igor

    2007-01-01

    We estimate character sums over points on elliptic curves over a finite field of q elements. Pseudorandom sequences can be constructed by taking linear combinations with small coefficients (for example, from the set {−1, 0, 1}) of a fixed vector of points, which forms the seed of the generator. We...... consider several particular cases of this general approach which are of special practical interest and have occurred in the literature. For each of them we show that the resulting sequence has good uniformity of distribution properties....

  9. genetics and inheritance of seed dormancy inflicted by seed

    African Journals Online (AJOL)

    Mgina

    ABSTRACT. The study was undertaken to investigate the genetic mode of inheritance of dormancy imposed by the hull (seed coat) in rice seeds. Freshly harvested seeds of parents, F1 and F2 populations of a cross between a dormant cultivar Kisegese and non-dormant strain K2004 were used. Germination test of the ...

  10. Seeds of confusion : the impact of policies on seed systems

    NARCIS (Netherlands)

    Louwaars, N.P.

    2007-01-01

    Seed is basic to crop production. Next to its importance in production, food security and rural development, seed is a key element in many debates about technology development and transfer, biodiversity, globalisation and equity. The sustainable availability of good quality seed is thus an important

  11. Effects of seed collecting date and storage duration on seed ...

    African Journals Online (AJOL)

    The objective of this study was to determine the effect of seed collecting dates (5 to 6 times from mid-November to early January, 10 days intervals) and seed storage duration (4, 8, and 12 months) at room temperature on seed germination of four Artemisia species (Artemisia sieberi, A. diffusa, A. kupetdaghensis, and A.

  12. Cone and seed yields in white spruce seed production areas

    Science.gov (United States)

    John A. Pitcher

    1966-01-01

    The source of seed is an important consideration in the reforestation program on the National Forests in the North Central Region. Thirty-five seed production areas have been set up in the Region, along the lines proposed by the North Central Forest Experiment Station, to provide control of seed source. Red pine, white pine, shortleaf and loblolly pine, and white...

  13. Curve Boxplot: Generalization of Boxplot for Ensembles of Curves.

    Science.gov (United States)

    Mirzargar, Mahsa; Whitaker, Ross T; Kirby, Robert M

    2014-12-01

    In simulation science, computational scientists often study the behavior of their simulations by repeated solutions with variations in parameters and/or boundary values or initial conditions. Through such simulation ensembles, one can try to understand or quantify the variability or uncertainty in a solution as a function of the various inputs or model assumptions. In response to a growing interest in simulation ensembles, the visualization community has developed a suite of methods for allowing users to observe and understand the properties of these ensembles in an efficient and effective manner. An important aspect of visualizing simulations is the analysis of derived features, often represented as points, surfaces, or curves. In this paper, we present a novel, nonparametric method for summarizing ensembles of 2D and 3D curves. We propose an extension of a method from descriptive statistics, data depth, to curves. We also demonstrate a set of rendering and visualization strategies for showing rank statistics of an ensemble of curves, which is a generalization of traditional whisker plots or boxplots to multidimensional curves. Results are presented for applications in neuroimaging, hurricane forecasting and fluid dynamics.

  14. Abscisic acid and ethephon regulation of cellulase in the endosperm cap and radicle during lettuce seed germination.

    Science.gov (United States)

    Chen, Bingxian; Ma, Jun; Xu, Zhenjiang; Wang, Xiaofeng

    2016-10-01

    The purpose of this study was to investigate the role of cellulase in endosperm cap weakening and radicle elongation during lettuce (Lactuca sativa L.) seed germination. The application of abscisic acid (ABA) or ethephon inhibits or promotes germination, respectively, by affecting endosperm cap weakening and radicle elongation. Cellulase activities, and related protein and transcript abundances of two lettuce cellulase genes, LsCEL1 and LsCEL2, increase in the endosperm cap and radicle prior to radicle protrusion following imbibition in water. ABA or ethephon reduce or elevate, respectively, cellulase activity, and related protein and transcript abundances in the endosperm cap. Taken together, these observations suggest that cellulase plays a role in endosperm cap weakening and radicle elongation during lettuce seed germination, and that the regulation of cellulase in the endosperm cap by ABA and ethephon play a role in endosperm cap weakening. However, the influence of ABA and ethephon on radicle elongation may not be through their effects on cellulase. © 2016 Institute of Botany, Chinese Academy of Sciences.

  15. seed germination and seedlings growth

    African Journals Online (AJOL)

    STORAGESEVER

    2007-12-17

    Dec 17, 2007 ... The role of 20E in plant physiology including seed germination is not studied. ..... GA3, ABA and CKs on lettuce Lactuca sativa seed germination are ..... Practical uses for ecdysteroids in mammals and humans: an update. J.

  16. Considerations for reference pump curves

    International Nuclear Information System (INIS)

    Stockton, N.B.

    1992-01-01

    This paper examines problems associated with inservice testing (IST) of pumps to assess their hydraulic performance using reference pump curves to establish acceptance criteria. Safety-related pumps at nuclear power plants are tested under the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code), Section 11. The Code requires testing pumps at specific reference points of differential pressure or flow rate that can be readily duplicated during subsequent tests. There are many cases where test conditions cannot be duplicated. For some pumps, such as service water or component cooling pumps, the flow rate at any time depends on plant conditions and the arrangement of multiple independent and constantly changing loads. System conditions cannot be controlled to duplicate a specific reference value. In these cases, utilities frequently request to use pump curves for comparison of test data for acceptance. There is no prescribed method for developing a pump reference curve. The methods vary and may yield substantially different results. Some results are conservative when compared to the Code requirements; some are not. The errors associated with different curve testing techniques should be understood and controlled within reasonable bounds. Manufacturer's pump curves, in general, are not sufficiently accurate to use as reference pump curves for IST. Testing using reference curves generated with polynomial least squares fits over limited ranges of pump operation, cubic spline interpolation, or cubic spline least squares fits can provide a measure of pump hydraulic performance that is at least as accurate as the Code required method. Regardless of the test method, error can be reduced by using more accurate instruments, by correcting for systematic errors, by increasing the number of data points, and by taking repetitive measurements at each data point

  17. (Lupinus albus) SEEDS

    African Journals Online (AJOL)

    user

    2010-08-08

    Aug 8, 2010 ... lupin samples indicated that lupins can be used as a raw material for various food ... lupin seeds can be utilized for milk and meat imitation products. ... estimated by multiplying the percentage of crude protein, crude fat and ...

  18. Seed for change

    NARCIS (Netherlands)

    Hassena Beko, Mohammed

    2017-01-01

    Ethiopia is an agrarian country where agriculture dominates the economy, and thus agriculture is considered as an engine of growth by the government. Seed as one of the agricultural technologies, in fact, a carrier of many technologies, is critical to increasing production, but the use of quality

  19. Managing Stress. Project Seed.

    Science.gov (United States)

    Muto, Donna; Wilk, Jan

    One of eight papers from Project Seed, this paper describes a stress management project undertaken with high school sophomores. Managing Stress is described as an interactive workshop that offers young people an opportunity to examine specific areas of stress in their lives and to learn effective ways to deal with them. The program described…

  20. Grape Seed Extract

    Science.gov (United States)

    ... Greece people have used grapes, grape leaves, and sap for health purposes. Grape seed extract was developed ... sharing research results, and educating the public. Its resources include publications (such as Dietary ... Department of Health & Human Services, National Institutes of Health, National Center for ...

  1. The SEED Initiative

    Science.gov (United States)

    Teich, Carolyn R.

    2011-01-01

    Committed to fulfilling the promise of the green economy, the American Association of Community Colleges (AACC) launched the Sustainability Education and Economic Development (SEED) initiative (www.theseedcenter.org) in October 2010. The project advances sustainability and clean energy workforce development practices at community colleges by…

  2. Dormancy in Plant Seeds

    NARCIS (Netherlands)

    Hilhorst, H.W.M.; Finch-Savage, W.E.; Buitink, J.; Bolingue, W.; Leubner-Metzger, G.

    2010-01-01

    Seed dormancy has been studied intensely over the past decades and, at present, knowledge of this plant trait is at the forefront of plant biology. The main model species is Arabidopsis thaliana, an annual weed, possessing nondeep physiological dormancy. This overview presents the state-of-the-art

  3. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    DePaoli, D.W.; Tsouris, C. [Oak Ridge National Lab., TN (United States); Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  4. Magnetic-seeding filtration

    International Nuclear Information System (INIS)

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira.

    1997-01-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process

  5. Curve Digitizer – A software for multiple curves digitizing

    Directory of Open Access Journals (Sweden)

    Florentin ŞPERLEA

    2010-06-01

    Full Text Available The Curve Digitizer is software that extracts data from an image file representing a graphicand returns them as pairs of numbers which can then be used for further analysis and applications.Numbers can be read on a computer screen stored in files or copied on paper. The final result is adata set that can be used with other tools such as MSEXCEL. Curve Digitizer provides a useful toolfor any researcher or engineer interested in quantifying the data displayed graphically. The image filecan be obtained by scanning a document

  6. [Study on seed testing for Salvia miltiorrhiza].

    Science.gov (United States)

    Dan, Hong-mei; Qi, Jian-jun; Zhou, Li-li; Li, Xian-en

    2008-09-01

    To establish a seed testing methods for Salvia miltiorrhiza. Referring to the International Seed Testing Rules made by ISTA and the Seed Testing for Crops (GB/T3543. 1-1995) issued by China. The seeds are selected by winnowing; the seed purity is about 50%-60%; 100 grain weight is used to determine the quality of the seed; the seed moisture content is determined by air drying, the drying hour is 3 h. Seed viability is tested by TFC method.

  7. Germination of red alder seed.

    Science.gov (United States)

    M.A. Radwan; D.S. DeBell

    1981-01-01

    Red alder seeds were collected from six locations throughout the natural range of the species. Each seed lot was obtained from a single tree, and the seeds were used to determine germination with and without stratification treatment. Irrespective of treatment, germination varied significantly (P

  8. Nest-mediated seed dispersal

    Science.gov (United States)

    Robert J. Warren; Jason P. Love; Mark A. Bradford

    2017-01-01

    Many plant seeds travel on the wind and through animal ingestion or adhesion; however, an overlooked dispersal mode may lurk within those dispersal modes. Viable seeds may remain attached or embedded within materials birds gather for nest building. Our objective was to determine if birds inadvertently transport seeds when they forage for plant materials to...

  9. Seed systems support in Kenya

    NARCIS (Netherlands)

    Munyi, Peter; Jonge, De Bram

    2015-01-01

    The threats of climate change and rising food prices have stirred renewed attention for seed and food security in Africa, inviting new thinking on the role of seed sector development in coping with these concerns. One conceptual framework that has gained attention is the Integrated Seed Sector

  10. Influence of postradiation moisture alteration on biological after-effect in Crepis seeds

    Energy Technology Data Exchange (ETDEWEB)

    Atayan, R R; Gabrielian, J Y [AN Armyanskoj SSR, Erevan. Inst. Fiziki

    1978-02-01

    A series of X-ray exposures was given to Crepis capillaris seeds of different water contents. Cytogenetic changes in the seeds were determined immediately after irradiation and after storage at different relative humidities. The amount of damage that developed during postirradiation storage as well as the initial radiobiological effect decreased as seed water content increased from 2.4% to 7.6 to 12.6%. Differences in postirradiation damage were revealed within four hours of storage and manifest as a fast component to the curve of storage versus damage. In seeds of 7.6 and 12.6% water content, both the amount of biological after-effect and the rate of injury progression did not depend markedly on relative humidity of storage atmosphere. These seeds demonstrated only a slow after-effect, which appeared to be the same at any seed-moisture level, thus indicating that only the fast component is subject to postirradiation modification. With dry irradiated seeds demonstrating fast postirradiation injury progression, the following results were obtained: (a) after-effect in seeds of 2.4% water content decreased with increasing humidity of storage atmosphere; no after-effect developed when the seeds were stored at 100% relative humidity; (b) after-effect in seeds of 6% water content was significantly increased if they were stored at 0% relative humidity. These results are consistent with the pattern expected of a free radical concept.

  11. Intra-specific downsizing of frugivores affects seed germination of fleshy-fruited plant species

    Science.gov (United States)

    Pérez-Méndez, Néstor; Rodríguez, Airam; Nogales, Manuel

    2018-01-01

    The loss of largest-bodied individuals within species of frugivorous animals is one of the major consequences of defaunation. The gradual disappearance of large-bodied frugivores is expected to entail a parallel deterioration in seed dispersal functionality if the remaining smaller-sized individuals are not so effective as seed dispersers. While the multiple impacts of the extinction of large bodied species have been relatively well studied, the impact of intraspecific downsizing (i.e. the extinction of large individuals within species) on seed dispersal has rarely been evaluated. Here we experimentally assessed the impact of body-size reduction in the frugivorous lizard Gallotia galloti (Lacertidae), an endemic species of the Canary Islands, on the seed germination patterns of two fleshy-fruited plant species (Rubia fruticosa and Withania aristata). Seed germination curves and the proportions of germinated seeds were compared for both plant species after being defecated by large-sized individuals and small-sized individuals. The data show that seeds of W. aristata defecated by larger-sized lizards germinated faster and in a higher percentage than those defecated by small-sized lizards, while no differences were found for R. fruticosa seeds. Our results suggest that disappearance of the largest individuals of frugivorous species may impair recruitment of some plant species by worsening seed germination. They also warn us of a potential cryptic loss of seed dispersal functionality on defaunated ecosystems, even when frugivorous species remain abundant.

  12. 7 CFR 201.15 - Weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation or...

  13. Calibration curves for biological dosimetry

    International Nuclear Information System (INIS)

    Guerrero C, C.; Brena V, M. . E-mail cgc@nuclear.inin.mx

    2004-01-01

    The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of 60 Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

  14. Vertex algebras and algebraic curves

    CERN Document Server

    Frenkel, Edward

    2004-01-01

    Vertex algebras are algebraic objects that encapsulate the concept of operator product expansion from two-dimensional conformal field theory. Vertex algebras are fast becoming ubiquitous in many areas of modern mathematics, with applications to representation theory, algebraic geometry, the theory of finite groups, modular functions, topology, integrable systems, and combinatorics. This book is an introduction to the theory of vertex algebras with a particular emphasis on the relationship with the geometry of algebraic curves. The notion of a vertex algebra is introduced in a coordinate-independent way, so that vertex operators become well defined on arbitrary smooth algebraic curves, possibly equipped with additional data, such as a vector bundle. Vertex algebras then appear as the algebraic objects encoding the geometric structure of various moduli spaces associated with algebraic curves. Therefore they may be used to give a geometric interpretation of various questions of representation theory. The book co...

  15. Curve collection, extension of databases

    International Nuclear Information System (INIS)

    Gillemot, F.

    1992-01-01

    Full text: Databases: generally calculated data only. The original measurements: diagrams. Information loss between them Expensive research eg. irradiation, aging, creep etc. Original curves should be stored for reanalysing. The format of the stored curves: a. Data in ASCII files, only numbers b. Other information in strings in a second file Same name, but different extension. Extensions shows the type of the test and the type of the file. EXAMPLES. TEN is tensile information, TED is tensile data, CHN is Charpy informations, CHD is Charpy data. Storing techniques: digitalised measurements, digitalising old curves stored on paper. Use: making catalogues, reanalysing, comparison with new data. Tools: mathematical software packages like quattro, genplot, exel, mathcad, qbasic, pascal, fortran, mathlab, grapher etc. (author)

  16. Rational points on elliptic curves

    CERN Document Server

    Silverman, Joseph H

    2015-01-01

    The theory of elliptic curves involves a pleasing blend of algebra, geometry, analysis, and number theory. This book stresses this interplay as it develops the basic theory, thereby providing an opportunity for advanced undergraduates to appreciate the unity of modern mathematics. At the same time, every effort has been made to use only methods and results commonly included in the undergraduate curriculum. This accessibility, the informal writing style, and a wealth of exercises make Rational Points on Elliptic Curves an ideal introduction for students at all levels who are interested in learning about Diophantine equations and arithmetic geometry. Most concretely, an elliptic curve is the set of zeroes of a cubic polynomial in two variables. If the polynomial has rational coefficients, then one can ask for a description of those zeroes whose coordinates are either integers or rational numbers. It is this number theoretic question that is the main subject of this book. Topics covered include the geometry and ...

  17. Theoretical melting curve of caesium

    International Nuclear Information System (INIS)

    Simozar, S.; Girifalco, L.A.; Pennsylvania Univ., Philadelphia

    1983-01-01

    A statistical-mechanical model is developed to account for the complex melting curve of caesium. The model assumes the existence of three different species of caesium defined by three different electronic states. On the basis of this model, the free energy of melting and the melting curve are computed up to 60 kbar, using the solid-state data and the initial slope of the fusion curve as input parameters. The calculated phase diagram agrees with experiment to within the experimental error. Other thermodynamic properties including the entropy and volume of melting were also computed, and they agree with experiment. Since the theory requires only one adjustable constant, this is taken as strong evidence that the three-species model is satisfactory for caesium. (author)

  18. Migration and the Wage Curve:

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke J.

    in a general equilibrium framework. For the empirical analysis we employ the IABS, a two percent sample of the German labor force. We find that the elasticity of the wage curve is particularly high for young workers and workers with a university degree, while it is low for older workers and workers......  Based on a wage curve approach we examine the labor market effects of migration in Germany. The wage curve relies on the assumption that wages respond to a change in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously...... with a vocational degree. The wage and employment effects of migration are moderate: a 1 percent increase in the German labor force through immigration increases the aggregate unemployment rate by less than 0.1 percentage points and reduces average wages by less 0.1 percent. While native workers benefit from...

  19. Laffer Curves and Home Production

    Directory of Open Access Journals (Sweden)

    Kotamäki Mauri

    2017-06-01

    Full Text Available In the earlier related literature, consumption tax rate Laffer curve is found to be strictly increasing (see Trabandt and Uhlig (2011. In this paper, a general equilibrium macro model is augmented by introducing a substitute for private consumption in the form of home production. The introduction of home production brings about an additional margin of adjustment – an increase in consumption tax rate not only decreases labor supply and reduces the consumption tax base but also allows a substitution of market goods with home-produced goods. The main objective of this paper is to show that, after the introduction of home production, the consumption tax Laffer curve exhibits an inverse U-shape. Also the income tax Laffer curves are significantly altered. The result shown in this paper casts doubt on some of the earlier results in the literature.

  20. Complexity of Curved Glass Structures

    Science.gov (United States)

    Kosić, T.; Svetel, I.; Cekić, Z.

    2017-11-01

    Despite the increasing number of research on the architectural structures of curvilinear forms and technological and practical improvement of the glass production observed over recent years, there is still a lack of comprehensive codes and standards, recommendations and experience data linked to real-life curved glass structures applications regarding design, manufacture, use, performance and economy. However, more and more complex buildings and structures with the large areas of glass envelope geometrically complex shape are built every year. The aim of the presented research is to collect data on the existing design philosophy on curved glass structure cases. The investigation includes a survey about how architects and engineers deal with different design aspects of curved glass structures with a special focus on the design and construction process, glass types and structural and fixing systems. The current paper gives a brief overview of the survey findings.

  1. Optimization on Spaces of Curves

    DEFF Research Database (Denmark)

    Møller-Andersen, Jakob

    in Rd, and methods to solve the initial and boundary value problem for geodesics allowing us to compute the Karcher mean and principal components analysis of data of curves. We apply the methods to study shape variation in synthetic data in the Kimia shape database, in HeLa cell nuclei and cycles...... of cardiac deformations. Finally we investigate a new application of Riemannian shape analysis in shape optimization. We setup a simple elliptic model problem, and describe how to apply shape calculus to obtain directional derivatives in the manifold of planar curves. We present an implementation based...

  2. Tracing a planar algebraic curve

    International Nuclear Information System (INIS)

    Chen Falai; Kozak, J.

    1994-09-01

    In this paper, an algorithm that determines a real algebraic curve is outlined. Its basic step is to divide the plane into subdomains that include only simple branches of the algebraic curve without singular points. Each of the branches is then stably and efficiently traced in the particular subdomain. Except for the tracing, the algorithm requires only a couple of simple operations on polynomials that can be carried out exactly if the coefficients are rational, and the determination of zeros of several polynomials of one variable. (author). 5 refs, 4 figs

  3. The New Keynesian Phillips Curve

    DEFF Research Database (Denmark)

    Ólafsson, Tjörvi

    This paper provides a survey on the recent literature on the new Keynesian Phillips curve: the controversies surrounding its microfoundation and estimation, the approaches that have been tried to improve its empirical fit and the challenges it faces adapting to the open-economy framework. The new......, learning or state-dependant pricing. The introduction of openeconomy factors into the new Keynesian Phillips curve complicate matters further as it must capture the nexus between price setting, inflation and the exchange rate. This is nevertheless a crucial feature for any model to be used for inflation...... forecasting in a small open economy like Iceland....

  4. Mechanical harvesting of pumpkin seeds

    OpenAIRE

    Sito, Stjepan; Ivančan, Stjepan; Barković, Edi; Mucalo, Ana

    2009-01-01

    One of the key problems in production technology of pumpkin seed for oil production is mechanized harvesting and losses of seed during mechanical harvesting. The losses of pumpkin seed during mechanical harvesting at peripheral velocity of 1.57 m/s (optimally adjusted machine) were 4.4% for Gleisdorf species, 5.2% for Slovenska species and 7.8% for pumpkin with husk. The higher average losses of pumpkin seed with husk were caused by tight connection of seed and pumpkin fruit.

  5. Irradiation effect on the seed vigor, SOD activity and MDA content in germinating seeds of yellow-seeded and black-seeded rape seed (Brassica napus L.)

    International Nuclear Information System (INIS)

    Han Jixiang; Hu Danhong; Liu Houli

    1993-01-01

    Seeds of a set of near-isogenic lines (Brassica napus L.) with different seed coat color from yellow to black were irradiated by 60 Co γ-rays of 150 krad. Seed vigor, superoxide dismutase (SOD) and malondialdehyde (MDA) in germinating seeds were analysed. In these characters, no significant difference between yellow-seeded lines (YLs) and black-seeded lines (BLs) showed before irradiation. But after irradiation, SOD activity in YLs was lower than that in BLs. While MDA content in YLs was obviously higher that that in DLs. As a result of irradiation, seed vigor of YLs was lower than that in BLs. these results indicated that the irradiation resistance of rape seed was related to the level of SOD as well as protective structure or substances in seed coat and that the radiosensitivity of YLs was higher than that of DLs

  6. Breeding for Grass Seed Yield

    DEFF Research Database (Denmark)

    Boelt, Birte; Studer, Bruno

    2010-01-01

    Seed yield is a trait of major interest for many fodder and amenity grass species and has received increasing attention since seed multiplication is economically relevant for novel grass cultivars to compete in the commercial market. Although seed yield is a complex trait and affected...... by agricultural practices as well as environmental factors, traits related to seed production reveal considerable genetic variation, prerequisite for improvement by direct or indirect selection. This chapter first reports on the biological and physiological basics of the grass reproduction system, then highlights...... important aspects and components affecting the seed yield potential and the agronomic and environmental aspects affecting the utilization and realization of the seed yield potential. Finally, it discusses the potential of plant breeding to sustainably improve total seed yield in fodder and amenity grasses....

  7. Signature Curves Statistics of DNA Supercoils

    OpenAIRE

    Shakiban, Cheri; Lloyd, Peter

    2004-01-01

    In this paper we describe the Euclidean signature curves for two dimensional closed curves in the plane and their generalization to closed space curves. The focus will be on discrete numerical methods for approximating such curves. Further we will apply these numerical methods to plot the signature curves related to three-dimensional simulated DNA supercoils. Our primary focus will be on statistical analysis of the data generated for the signature curves of the supercoils. We will try to esta...

  8. Dual Smarandache Curves of a Timelike Curve lying on Unit dual Lorentzian Sphere

    OpenAIRE

    Kahraman, Tanju; Hüseyin Ugurlu, Hasan

    2016-01-01

    In this paper, we give Darboux approximation for dual Smarandache curves of time like curve on unit dual Lorentzian sphere. Firstly, we define the four types of dual Smarandache curves of a timelike curve lying on dual Lorentzian sphere.

  9. Physiological quality and seed respiration of primed Jatropha curcas seeds

    Directory of Open Access Journals (Sweden)

    Micheli Angelica Horbach

    2017-11-01

    Full Text Available ABSTRACT Seed deterioration is a natural and irreversible process. Nevertheless, seed priming with water and antioxidants can minimize oxidative damage in oilseeds, resulting in attenuation of seed deterioration. The objective of this assay was to evaluate seed priming on respiratory activity of Jatropha curcas submitted to accelerated aging. Seeds from two provenances (Janauba and Pedro J. Caballero were submitted to three priming treatments (control, immersion in deionized water, and with 750 µmol L-1 of ascorbic acid and treated for accelerated aging at 41 °C for 72 h. The results showed that the priming of J. curcas seeds promoted tolerance to accelerated aging. Primed seeds, with ascorbic acid from Janauba and deionized water from Pedro J. Caballero, resulted in a higher percentage of normal seedlings, and increased germination speed index and seed respiration. The decline of physiological quality of J. curcas seeds after accelerated aging is directly associated with a reduction in respiratory activity that is related to seed moisture content.

  10. Electro-Mechanical Resonance Curves

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2018-01-01

    Recently I have been investigating the frequency response of galvanometers. These are direct-current devices used to measure small currents. By using a low-frequency function generator to supply the alternating-current signal and a stopwatch smartphone app to measure the period, I was able to take data to allow a resonance curve to be drawn. This…

  11. Texas curve margin of safety.

    Science.gov (United States)

    2013-01-01

    This software can be used to assist with the assessment of margin of safety for a horizontal curve. It is intended for use by engineers and technicians responsible for safety analysis or management of rural highway pavement or traffic control devices...

  12. Principal Curves on Riemannian Manifolds.

    Science.gov (United States)

    Hauberg, Soren

    2016-09-01

    Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.

  13. Elliptic curves and primality proving

    Science.gov (United States)

    Atkin, A. O. L.; Morain, F.

    1993-07-01

    The aim of this paper is to describe the theory and implementation of the Elliptic Curve Primality Proving algorithm. Problema, numeros primos a compositis dignoscendi, hosque in factores suos primos resolvendi, ad gravissima ac utilissima totius arithmeticae pertinere, et geometrarum tum veterum tum recentiorum industriam ac sagacitatem occupavisse, tam notum est, ut de hac re copiose loqui superfluum foret.

  14. A Curve for all Reasons

    Indian Academy of Sciences (India)

    from biology, feel that every pattern in the living world, ranging from the folding of ... curves band c have the same rate of increase but reach different asymptotes. If these .... not at x = 0, but at xo' which is the minimum size at birth that will permit ...

  15. Survival curves for irradiated cells

    International Nuclear Information System (INIS)

    Gibson, D.K.

    1975-01-01

    The subject of the lecture is the probability of survival of biological cells which have been subjected to ionising radiation. The basic mathematical theories of cell survival as a function of radiation dose are developed. A brief comparison with observed survival curves is made. (author)

  16. Mentorship, learning curves, and balance.

    Science.gov (United States)

    Cohen, Meryl S; Jacobs, Jeffrey P; Quintessenza, James A; Chai, Paul J; Lindberg, Harald L; Dickey, Jamie; Ungerleider, Ross M

    2007-09-01

    Professionals working in the arena of health care face a variety of challenges as their careers evolve and develop. In this review, we analyze the role of mentorship, learning curves, and balance in overcoming challenges that all such professionals are likely to encounter. These challenges can exist both in professional and personal life. As any professional involved in health care matures, complex professional skills must be mastered, and new professional skills must be acquired. These skills are both technical and judgmental. In most circumstances, these skills must be learned. In 2007, despite the continued need for obtaining new knowledge and learning new skills, the professional and public tolerance for a "learning curve" is much less than in previous decades. Mentorship is the key to success in these endeavours. The success of mentorship is two-sided, with responsibilities for both the mentor and the mentee. The benefits of this relationship must be bidirectional. It is the responsibility of both the student and the mentor to assure this bidirectional exchange of benefit. This relationship requires time, patience, dedication, and to some degree selflessness. This mentorship will ultimately be the best tool for mastering complex professional skills and maturing through various learning curves. Professional mentorship also requires that mentors identify and explicitly teach their mentees the relational skills and abilities inherent in learning the management of the triad of self, relationships with others, and professional responsibilities.Up to two decades ago, a learning curve was tolerated, and even expected, while professionals involved in healthcare developed the techniques that allowed for the treatment of previously untreatable diseases. Outcomes have now improved to the point that this type of learning curve is no longer acceptable to the public. Still, professionals must learn to perform and develop independence and confidence. The responsibility to

  17. Empty seeds are not always bad: simultaneous effect of seed emptiness and masting on animal seed predation.

    Directory of Open Access Journals (Sweden)

    Ramón Perea

    Full Text Available Seed masting and production of empty seeds have often been considered independently as different strategies to reduce seed predation by animals. Here, we integrate both phenomena within the whole assemblage of seed predators (both pre and post-dispersal and in two contrasting microsites (open vs. sheltered to improve our understanding of the factors controlling seed predation in a wind-dispersed tree (Ulmus laevis. In years with larger crop sizes more avian seed predators were attracted with an increase in the proportion of full seeds predated on the ground. However, for abundant crops, the presence of empty seeds decreased the proportion of full seeds predated. Empty seeds remained for a very long period in the tree, making location of full seeds more difficult for pre-dispersal predators and expanding the overall seed drop period at a very low cost (in dry biomass and allocation of C, N and P. Parthenocarpy (non-fertilized seeds was the main cause of seed emptiness whereas seed abortion was produced in low quantity. These aborted seeds fell prematurely and, thus, could not work as deceptive seeds. A proportion of 50% empty seeds significantly reduced ground seed predation by 26%. However, a high rate of parthenocarpy (beyond 50% empty seeds did not significantly reduce seed predation in comparison to 50% empty seeds. We also found a high variability and unpredictability in the production of empty seeds, both at tree and population level, making predator deception more effective. Open areas were especially important to facilitate seed survival since rodents (the main post-dispersal predators consumed seeds mostly under shrub cover. In elm trees parthenocarpy is a common event that might work as an adaptive strategy to reduce seed predation. Masting per se did not apparently reduce the overall proportion of seeds predated in this wind-dispersed tree, but kept great numbers of seeds unconsumed.

  18. Seeds of the Future

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Five of the global issues most frequently debated today are the decline of biodiversity in general and of agrobiodiversity in particular, climate change, hunger and malnutrition, poverty and water. These issues are connected with each other, and should be dealt with as such. Most of our food comes from seeds (even when we eat meat, we indirectly eat plants, which come from seeds) and food affects our health. The evolution of plant breeding, the science which is responsible for the type and the diversity of seed that farmers plant, and hence for the diversity of food that we eat, helps us understand how agrobiodiversity has decreased. An agro-ecological model of agriculture could be solution to the most important problems affecting the planet, but is often criticized for not being able to produce enough food for a growing population casting doubts on whether food security and food safety can be compatible objectives. Participatory and evolutionary plant breeding, while benefiting from advances in molecular g...

  19. The Seed Repair Response during Germination: Disclosing Correlations between DNA Repair, Antioxidant Response, and Chromatin Remodeling in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Andrea Pagano

    2017-11-01

    Full Text Available This work provides novel insights into the effects caused by the histone deacetylase inhibitor trichostatin A (TSA during Medicago truncatula seed germination, with emphasis on the seed repair response. Seeds treated with H2O and TSA (10 and 20 μM were collected during imbibition (8 h and at the radicle protrusion phase. Biometric data showed delayed germination and impaired seedling growth in TSA-treated samples. Comet assay, performed on radicles at the protrusion phase and 4-days old M. truncatula seedlings, revealed accumulation of DNA strand breaks upon exposure to TSA. Activation of DNA repair toward TSA-mediated genotoxic damage was evidenced by the up-regulation of MtOGG1(8-OXOGUANINE GLYCOSYLASE/LYASE gene involved in the removal of oxidative DNA lesions, MtLIGIV(LIGASE IV gene, a key determinant of seed quality, required for the rejoining of DNA double strand breaks and TDP(TYROSYL-DNA PHOSPHODIESTERASE genes encoding the multipurpose DNA repair enzymes tyrosyl-DNA phosphodiesterases. Since radical scavenging can prevent DNA damage, the specific antioxidant activity (SAA was measured by DPPH (1,1-diphenyl-2-picrylhydrazyl and Folin-Ciocalteu reagent assays. Fluctuations of SAA were observed in TSA-treated seeds/seedlings concomitant with the up-regulation of antioxidant genes MtSOD(SUPEROXIDE DISMUTASE, MtAPX(ASCORBATE PEROXIDASE and MtMT2(TYPE 2 METALLOTHIONEIN. Chromatin remodeling, required to facilitate the access of DNA repair enzymes at the damaged sites, is also part of the multifaceted seed repair response. To address this aspect, still poorly explored in plants, the MtTRRAP(TRANSFORMATION/TRANSACTIVATION DOMAIN-ASSOCIATED PROTEIN gene was analyzed. TRRAP is a transcriptional adaptor, so far characterized only in human cells where it is needed for the recruitment of histone acetyltransferase complexes to chromatin during DNA repair. The MtTRRAP gene and the predicted interacting partners MtHAM2 (HISTONE ACETYLTRANSFERASE OF

  20. Physicochemical Evaluation of Seeds and Oil of Nontraditional Oil Seeds

    Directory of Open Access Journals (Sweden)

    Adam Ismail Ahmed

    2015-08-01

    Full Text Available The present work was conducted in the Laboratory of Biochemistry and Food science department, Faculty of Natural Resources and Environmental Studies, University of Kordofan, in order to evaluate some nontraditional oil seeds these are i.e. Marula (Sclerocarya birrea, Roselle (Hibiscus sabdariffa L. seeds and Christ’s thorn (Zizyphus spina-christi seeds. The seeds of the roselle and Christ’s thorn fruits were procured from Elobeid local market, North Kordofan State, while marula fruits were obtained from Elnuhod, West Kordofan State. The proximate composition of the seeds, cake and christ’s thorn pulp was done. Some chemical and physical properties were performed for the extracted oil. The results revealed that proximate composition of the seeds and cake differ statistically among the studied materials. Significant differences were observed among the oil extracted from these species; moreover, these oils differ significantly in color and viscosity only.

  1. Sunflower seed allergy

    Science.gov (United States)

    Ukleja-Sokołowska, Natalia; Gawrońska-Ukleja, Ewa; Żbikowska-Gotz, Magdalena; Bartuzi, Zbigniew; Sokołowski, Łukasz

    2016-01-01

    Sunflower seeds are a rare source of allergy, but several cases of occupational allergies to sunflowers have been described. Sunflower allergens on the whole, however, still await precise and systematic description. We present an interesting case of a 40-year-old male patient, admitted to hospital due to shortness of breath and urticaria, both of which appeared shortly after the patient ingested sunflower seeds. Our laryngological examination revealed swelling of the pharynx with retention of saliva and swelling of the mouth and tongue. During diagnostics, 2 months later, we found that skin prick tests were positive to mugwort pollen (12/9 mm), oranges (6/6 mm), egg protein (3/3 mm), and hazelnuts (3/3 mm). A native prick by prick test with sunflower seeds was strongly positive (8/5 mm). Elevated concentrations of specific IgE against weed mix (inc. lenscale, mugwort, ragweed) allergens (1.04 IU/mL), Artemisia vulgaris (1.36 IU/mL), and Artemisia absinthium (0.49 IU/mL) were found. An ImmunoCap ISAC test found an average level of specific IgE against mugwort pollen allergen component Art v 1 - 5,7 ISU-E, indicating an allergy to mugwort pollen and low to medium levels of specific IgE against lipid transfer proteins (LTP) found in walnuts, peanuts, mugwort pollen, and hazelnuts. Through the ISAC inhibition test we proved that sunflower seed allergen extracts contain proteins cross-reactive with patients’ IgE specific to Art v 1, Art v 3, and Jug r 3. Based on our results and the clinical pattern of the disease we confirmed that the patient is allergic to mugwort pollen and that he had an anaphylactic reaction as a result of ingesting sunflower seeds. We suspected that hypersensitivity to sunflower LTP and defensin-like proteins, both cross-reactive with mugwort pollen allergens, were the main cause of the patient’s anaphylactic reaction. PMID:27222528

  2. Determination of oil in seeds by a wide line NMR instrument

    International Nuclear Information System (INIS)

    Marton, Aurel

    1983-01-01

    The oil content of sunflower, rape and soybean seeds was determined by a wide line NMR instrument. Using various model systems the following conclusions were drawn: the sensitivity of the instrument is much higher for the oil content of the seeds than for their water content. This observation can be interpreted in terms of the longer relaxation time of the water protons. The quantitative determination of the oil content of the seeds can be done with a high accuracy provided that the calibration curve for the respective oil is available and the signal of the solid state components of the seeds is corrected. If the water content of the seeds is reduced below 5 per cent, the oil content values obtained by NMR and extraction techniques are in agreement within the experimental error. (author)

  3. A catalog of special plane curves

    CERN Document Server

    Lawrence, J Dennis

    2014-01-01

    Among the largest, finest collections available-illustrated not only once for each curve, but also for various values of any parameters present. Covers general properties of curves and types of derived curves. Curves illustrated by a CalComp digital incremental plotter. 12 illustrations.

  4. Computation of undulator tuning curves

    International Nuclear Information System (INIS)

    Dejus, Roger J.

    1997-01-01

    Computer codes for fast computation of on-axis brilliance tuning curves and flux tuning curves have been developed. They are valid for an ideal device (regular planar device or a helical device) using the Bessel function formalism. The effects of the particle beam emittance and the beam energy spread on the spectrum are taken into account. The applicability of the codes and the importance of magnetic field errors of real insertion devices are addressed. The validity of the codes has been experimentally verified at the APS and observed discrepancies are in agreement with predicted reduction of intensities due to magnetic field errors. The codes are distributed as part of the graphical user interface XOP (X-ray OPtics utilities), which simplifies execution and viewing of the results

  5. Curved canals: Ancestral files revisited

    Directory of Open Access Journals (Sweden)

    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

  6. Invariance for Single Curved Manifold

    KAUST Repository

    Castro, Pedro Machado Manhaes de

    2012-01-01

    Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.

  7. Invariance for Single Curved Manifold

    KAUST Repository

    Castro, Pedro Machado Manhaes de

    2012-08-01

    Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.

  8. Curved Folded Plate Timber Structures

    OpenAIRE

    Buri, Hans Ulrich; Stotz, Ivo; Weinand, Yves

    2011-01-01

    This work investigates the development of a Curved Origami Prototype made with timber panels. In the last fifteen years the timber industry has developed new, large size, timber panels. Composition and dimensions of these panels and the possibility of milling them with Computer Numerical Controlled machines shows great potential for folded plate structures. To generate the form of these structures we were inspired by Origami, the Japanese art of paper folding. Common paper tessellations are c...

  9. Experimental dosimetry of Ho-166 bioglass seed polymer-protected

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Luciana B.; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This study aims to develop experimental dosimetry of Ho-166 bio glass seed for brachytherapy studies using GAFCHROMIC EBT2 radio chromium films. The methodology consists of placement of radio chromium films in a compressed breast phantom, along with bio glass polymer-protected seeds of [Si: Ca: Ho] and [Si: Ca: Ho: Zr]. The bio glass seeds were encapsulated with polyvinyl alcohol, before being activated and used in the study. The bio glass seeds were introduced into the breast phantom, along with radio chromium films for a period of 2 hours. After the exposure time, radio chromium films were removed from phantom and digitized for analysis in ImageDIG 2.0 program, which quantifies the intensity of RGB (Red, Green, Blue). The dose calculation was evaluated by Monte Carlo technique. Experimental and theoretical data were used to calibrate the dose distribution. The results were plotted on graphs and dose iso curves were obtained. As conclusion it is possible to perform dosimetry in Ho-166 seed brachytherapy using radio chromium films, limited to a short exposure time and small activity. (author)

  10. Experimental dosimetry of Ho-166 bioglass seed polymer-protected

    International Nuclear Information System (INIS)

    Nogueira, Luciana B.; Campos, Tarcisio P.R.

    2011-01-01

    This study aims to develop experimental dosimetry of Ho-166 bio glass seed for brachytherapy studies using GAFCHROMIC EBT2 radio chromium films. The methodology consists of placement of radio chromium films in a compressed breast phantom, along with bio glass polymer-protected seeds of [Si: Ca: Ho] and [Si: Ca: Ho: Zr]. The bio glass seeds were encapsulated with polyvinyl alcohol, before being activated and used in the study. The bio glass seeds were introduced into the breast phantom, along with radio chromium films for a period of 2 hours. After the exposure time, radio chromium films were removed from phantom and digitized for analysis in ImageDIG 2.0 program, which quantifies the intensity of RGB (Red, Green, Blue). The dose calculation was evaluated by Monte Carlo technique. Experimental and theoretical data were used to calibrate the dose distribution. The results were plotted on graphs and dose iso curves were obtained. As conclusion it is possible to perform dosimetry in Ho-166 seed brachytherapy using radio chromium films, limited to a short exposure time and small activity. (author)

  11. Projection-based curve clustering

    International Nuclear Information System (INIS)

    Auder, Benjamin; Fischer, Aurelie

    2012-01-01

    This paper focuses on unsupervised curve classification in the context of nuclear industry. At the Commissariat a l'Energie Atomique (CEA), Cadarache (France), the thermal-hydraulic computer code CATHARE is used to study the reliability of reactor vessels. The code inputs are physical parameters and the outputs are time evolution curves of a few other physical quantities. As the CATHARE code is quite complex and CPU time-consuming, it has to be approximated by a regression model. This regression process involves a clustering step. In the present paper, the CATHARE output curves are clustered using a k-means scheme, with a projection onto a lower dimensional space. We study the properties of the empirically optimal cluster centres found by the clustering method based on projections, compared with the 'true' ones. The choice of the projection basis is discussed, and an algorithm is implemented to select the best projection basis among a library of orthonormal bases. The approach is illustrated on a simulated example and then applied to the industrial problem. (authors)

  12. Growth curves for Laron syndrome.

    Science.gov (United States)

    Laron, Z; Lilos, P; Klinger, B

    1993-01-01

    Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls completed their growth between the age of 16-19 years to a final mean (SD) height of 119 (8.5) cm whereas the boys continued growing beyond the age of 20 years, achieving a final height of 124 (8.5) cm. At all ages the upper to lower body segment ratio was more than 2 SD above the normal mean. These growth curves constitute a model not only for primary, hereditary insulin-like growth factor-I (IGF-I) deficiency (Laron syndrome) but also for untreated secondary IGF-I deficiencies such as growth hormone gene deletion and idiopathic congenital isolated growth hormone deficiency. They should also be useful in the follow up of children with Laron syndrome treated with biosynthetic recombinant IGF-I. PMID:8333769

  13. Elementary particles in curved spaces

    International Nuclear Information System (INIS)

    Lazanu, I.

    2004-01-01

    The theories in particle physics are developed currently, in Minkowski space-time starting from the Poincare group. A physical theory in flat space can be seen as the limit of a more general physical theory in a curved space. At the present time, a theory of particles in curved space does not exist, and thus the only possibility is to extend the existent theories in these spaces. A formidable obstacle to the extension of physical models is the absence of groups of motion in more general Riemann spaces. A space of constant curvature has a group of motion that, although differs from that of a flat space, has the same number of parameters and could permit some generalisations. In this contribution we try to investigate some physical implications of the presumable existence of elementary particles in curved space. In de Sitter space (dS) the invariant rest mass is a combination of the Poincare rest mass and the generalised angular momentum of a particle and it permits to establish a correlation with the vacuum energy and with the cosmological constant. The consequences are significant because in an experiment the local structure of space-time departs from the Minkowski space and becomes a dS or AdS space-time. Discrete symmetry characteristics of the dS/AdS group suggest some arguments for the possible existence of the 'mirror matter'. (author)

  14. Pathogenic mycoflora on carrot seeds

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available Altogether 300 seed samples were collected during 9 years in 8 regions of Poland and the fungi Were isolated and their pathogenicity to carrot seedlings was examined. Alternaria rudicina provcd to be the most important pathogen although. A. alternata was more common. The other important pathogens were Fusarium spp., Phoma spp. and Botrytis cinerea. The infection of carrot seeds by A. radicina should be used as an important criterium in seed quality evaluation.

  15. Maturation of sugar maple seed

    Science.gov (United States)

    Clayton M., Jr. Carl; Albert G., Jr. Snow; Albert G. Snow

    1971-01-01

    The seeds of a sugar maple tree (Acer saccharum Marsh.) do not mature at the same time every year. And different trees mature their seeds at different times. So time of year is not a reliable measure of when seeds are ripe. Better criteria are needed. In recent studies we have found that moisture content and color are the best criteria for judging when sugar maple...

  16. Efeito da temperatura de armazenamento e de fitoreguladores na germinação de sementes de maracujá doce e desenvolvimento inicial de mudas = Effect of storage temperature and phytoregulators on germination of sweet passion fruit seeds and seedling development

    Directory of Open Access Journals (Sweden)

    Marco Eustáquio de Sá

    2006-07-01

    Full Text Available A germinação de sementes de maracujazeiro doce apresenta problemas e estudos que possam elucidar o processo e verificar sua viabilidade são importantes para que os produtores de mudas possam melhorar seu rendimento e obter maiores lucros. O objetivo do trabalho foi verificar o efeito da temperatura de armazenamento das sementes, e embebição em fitoreguladores e KNO3 na germinação e desenvolvimento inicial de mudas de maracujá doce. O experimento foi instalado na Casa de Vegetação, da Faculdade de Engenharia de Ilha Solteira/Unesp, Estado de São Paulo, em delineamento inteiramente casualizado, numesquema fatorial 2 X 5, sendo 2 temperaturas de armazenamento das sementes (ambiente e geladeira e 5 tratamentos de embebição (sem embebição, água destilada, giberelina 250 ppm, citocinina 250 ppm e KNO3 0,1%, com 4 repetições. As sementes foram armazenadas por 20dias, seguidas de embebição por 24 horas. As avaliações foram feitas até os 62 dias após a semeadura, determinando-se porcentagem de germinação, o índice velocidade de germinação e parâmetros do desenvolvimento inicial das mudas. A baixa temperatura teve efeito positivo na germinação. A giberelina influenciou positivamente o desenvolvimento inicial das mudas, constatando-se que o seu efeito pode ser perfeitamente substituído pela baixa temperatura dearmazenamento das sementes.The germination of sweet passion fruit seeds has problems. Studies that explain and verify its viability are important for seedproducers to improve their income and profit. The aim of this work was to verify the effect of storage temperature and imbibition in phytoregulators and KNO2 on germination and seedling development of passion fruit. The experiment was carried out at Casa de Vegetação from Faculdade de Engenharia de Ilha Solteira/Unesp, São Paulo State, using a completely randomized design in a 2 (storage temperature of seeds (room temperature and refrigerator x 5 (imbibition

  17. Dual Smarandache Curves and Smarandache Ruled Surfaces

    OpenAIRE

    Tanju KAHRAMAN; Mehmet ÖNDER; H. Hüseyin UGURLU

    2013-01-01

    In this paper, by considering dual geodesic trihedron (dual Darboux frame) we define dual Smarandache curves lying fully on dual unit sphere S^2 and corresponding to ruled surfaces. We obtain the relationships between the elements of curvature of dual spherical curve (ruled surface) x(s) and its dual Smarandache curve (Smarandache ruled surface) x1(s) and we give an example for dual Smarandache curves of a dual spherical curve.

  18. Within canopy distribution of cotton seed N

    Science.gov (United States)

    Whole cotton seeds can be an important component of dairy rations. Nitrogen content of the seed is an important determinant of the feed value of the seed. Efforts to increase the seed value as feed will be enhanced with knowledge of the range and distribution of seed N within the cotton crop. This s...

  19. A role for seed storage proteins in Arabidopsis seed longevity

    NARCIS (Netherlands)

    Nguyen, Thu-Phuong|info:eu-repo/dai/nl/328228818; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie|info:eu-repo/dai/nl/241338735

    2015-01-01

    Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana

  20. 19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

  1. Seed dormancy and seed longevity: from genetic variation to gene identification

    NARCIS (Netherlands)

    Nguyen, T.P.

    2014-01-01

    Seed dormancy and seed longevity are the most important survival traits in the soil seed bank. Both traits are induced during seed maturation and evolved to assure seed survival during environmental conditions that cannot support the regular course of life. Seed dormancy is related to the timing of

  2. Why high seed densities within buried mesh bags may overestimate depletion rates of soil seed banks

    NARCIS (Netherlands)

    Mourik, van T.A.; Stomph, T.J.; Murdoch, A.J.

    2005-01-01

    1. Estimates of seed bank depletion rates are essential for modelling and management of plant populations. The seed bag burial method is often used to measure seed mortality in the soil. However, the density of seeds within seed bags is higher than densities in natural seed banks, which may elevate

  3. Heirloom biodynamic seeds network rescue, conservation and multiplication of local seeds in Brazil

    OpenAIRE

    Jovchelevich, Pedro

    2014-01-01

    Structuring a network organic and biodynamic seed involving farmers in the central- southern Brazil. Training, participatory breeding, edition of publications, fairs of exchange seeds, a processing unit and assessment of seed quality, commercial seed multiplication with emphasis on vegetables. This network has garanteed the autonomy of farmers in seed production and enriched agrobiodiversity through exchanges of seed.

  4. Bubble number saturation curve and asymptotics of hypobaric and hyperbaric exposures.

    Science.gov (United States)

    Wienke, B R

    1991-12-01

    Within bubble number limits of the varying permeability and reduced gradient bubble models, it is shown that a linear form of the saturation curve for hyperbaric exposures and a nearly constant decompression ratio for hypobaric exposures are simultaneously recovered from the phase volume constraint. Both limits are maintained within a single bubble number saturation curve. A bubble term, varying exponentially with inverse pressure, provides closure. Two constants describe the saturation curve, both linked to seed numbers. Limits of other decompression models are also discussed and contrasted for completeness. It is suggested that the bubble number saturation curve thus provides a consistent link between hypobaric and hyperbaric data, a link not established by earlier decompression models.

  5. Seed drill depth control system for precision seeding

    DEFF Research Database (Denmark)

    Kirkegaard Nielsen, Søren; Munkholm, Lars Juhl; Lamandé, Mathieu

    2018-01-01

    acting on the drill coulters, which generates unwanted vibrations and, consequently, a non-uniform seed placement. Therefore, a proof-of-concept dynamic coulter depth control system for a low-cost seed drill was developed and studied in a field experiment. The performance of the active control system...... depth control system this variability was reduced to±2 mm. The system with the active control system operated more accurately at an operational speed of 12 km h−1 than at 4 km h−1 without the activated control system.......An adequate and uniform seeding depth is crucial for the homogeneous development of a crop, as it affects time of emergence and germination rate. The considerable depth variations observed during seeding operations - even for modern seed drills - are mainly caused by variability in soil resistance...

  6. A note on families of fragility curves

    International Nuclear Information System (INIS)

    Kaplan, S.; Bier, V.M.; Bley, D.C.

    1989-01-01

    In the quantitative assessment of seismic risk, uncertainty in the fragility of a structural component is usually expressed by putting forth a family of fragility curves, with probability serving as the parameter of the family. Commonly, a lognormal shape is used both for the individual curves and for the expression of uncertainty over the family. A so-called composite single curve can also be drawn and used for purposes of approximation. This composite curve is often regarded as equivalent to the mean curve of the family. The equality seems intuitively reasonable, but according to the authors has never been proven. The paper presented proves this equivalence hypothesis mathematically. Moreover, the authors show that this equivalence hypothesis between fragility curves is itself equivalent to an identity property of the standard normal probability curve. Thus, in the course of proving the fragility curve hypothesis, the authors have also proved a rather obscure, but interesting and perhaps previously unrecognized, property of the standard normal curve

  7. Observable Zitterbewegung in curved spacetimes

    Science.gov (United States)

    Kobakhidze, Archil; Manning, Adrian; Tureanu, Anca

    2016-06-01

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  8. Observable Zitterbewegung in curved spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Kobakhidze, Archil, E-mail: archilk@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Manning, Adrian, E-mail: a.manning@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Tureanu, Anca, E-mail: anca.tureanu@helsinki.fi [Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki (Finland)

    2016-06-10

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  9. Differential geometry curves, surfaces, manifolds

    CERN Document Server

    Kohnel, Wolfgang

    2002-01-01

    This carefully written book is an introduction to the beautiful ideas and results of differential geometry. The first half covers the geometry of curves and surfaces, which provide much of the motivation and intuition for the general theory. Special topics that are explored include Frenet frames, ruled surfaces, minimal surfaces and the Gauss-Bonnet theorem. The second part is an introduction to the geometry of general manifolds, with particular emphasis on connections and curvature. The final two chapters are insightful examinations of the special cases of spaces of constant curvature and Einstein manifolds. The text is illustrated with many figures and examples. The prerequisites are undergraduate analysis and linear algebra.

  10. LINS Curve in Romanian Economy

    Directory of Open Access Journals (Sweden)

    Emilian Dobrescu

    2016-02-01

    Full Text Available The paper presents theoretical considerations and empirical evidence to test the validity of the Laffer in Narrower Sense (LINS curve as a parabola with a maximum. Attention is focused on the so-called legal-effective tax gap (letg. The econometric application is based on statistical data (1990-2013 for Romania as an emerging European economy. Three cointegrating regressions (fully modified least squares, canonical cointegrating regression and dynamic least squares and three algorithms, which are based on instrumental variables (two-stage least squares, generalized method of moments, and limited information maximum likelihood, are involved.

  11. 7 CFR 201.50 - Weed seed.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Purity Analysis in the Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or... sieve are considered weed seeds. For wild onion and wild garlic (Allium spp.) bulblets classed as inert...

  12. Differential geometry and topology of curves

    CERN Document Server

    Animov, Yu

    2001-01-01

    Differential geometry is an actively developing area of modern mathematics. This volume presents a classical approach to the general topics of the geometry of curves, including the theory of curves in n-dimensional Euclidean space. The author investigates problems for special classes of curves and gives the working method used to obtain the conditions for closed polygonal curves. The proof of the Bakel-Werner theorem in conditions of boundedness for curves with periodic curvature and torsion is also presented. This volume also highlights the contributions made by great geometers. past and present, to differential geometry and the topology of curves.

  13. Seeding and planting upland oaks

    Science.gov (United States)

    1989-01-01

    Oaks can be planted or seeded in uplands to: (1) afforest old fields, strip-mined areas, or other areas devoid of trees, and (2) supplement natural reproduction within existing forests. Planting is usually more successful than direct seeding. But even under good conditions survival and growth of planted oak has been considerably poorer than with conifers and other...

  14. STORAGE OF Handroanthus umbellatus SEEDS

    Directory of Open Access Journals (Sweden)

    Cibele Chalita Martins

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1980509815725Seed storage under controlled environmental conditions represents one of the most important lines of research to be applied on short-lived forest species as Handroanthus. The present research aimed to identify the most suitable seed storage conditions and longevity behavior of Handroanthus umbellatus seeds subject to the following storage treatments: packaging permeable paper bags under a no-controlled laboratory temperature and humidity (control and multiwall semipermeable bag at temperatures of -18 ºC, 1 ºC and 25 ºC. Seeds were dried to 6.3% of water content. Stored seeds were evaluated every three months until 24 months for water content, germination percentage and vigor utilizing first counting test. Seeds of T. umbellata are orthodox, with low longevity under natural conditions, once they remain viable for less than 5 months. The best conditions of seed preservation of these species were obtained by storage at -18° C in multiwall bags. Under these conditions physiological seed quality remains unchanged for a 24-month period.

  15. Uganda Early Generation Seed Study

    NARCIS (Netherlands)

    Mastenbroek, A.; Ntare, Bonny

    2016-01-01

    One of the major bottlenecks limiting farmers’ access to good quality seed for food crops in Uganda is the shortage of early generation seed (EGS - breeder and foundation) to produce sufficient quantities of certified and/or quality declared) to satisfy the needs of farmers. A national study was

  16. Insecticide seed treatments for sugarbeet

    Science.gov (United States)

    Pest feeding and vectoring of viruses cause serious problems in sugarbeet production worldwide. In order to ameliorate pest and disease problems on sugarbeet, two seed treatments, Poncho Beta (60 g a.i. clothianidin + 8 g a.i. beta-cyfluthrin/100,000 seed) and Cruiser Tef (60 g a.i. thiamethoxam + 8...

  17. Orthodox seeds and resurrection plants

    NARCIS (Netherlands)

    Costa, Maria Cecília Dias; Cooper, Keren; Hilhorst, Henk W.M.; Farrant, Jill M.

    2017-01-01

    Although staple crops do not survive extended periods of drought, their seeds possess desiccation tolerance (DT), as they survive almost complete dehydration (desiccation) during the late maturation phase of development. Resurrection plants are plant species whose seeds and vegetative tissues are

  18. Efficient computation of spaced seeds

    Directory of Open Access Journals (Sweden)

    Ilie Silvana

    2012-02-01

    Full Text Available Abstract Background The most frequently used tools in bioinformatics are those searching for similarities, or local alignments, between biological sequences. Since the exact dynamic programming algorithm is quadratic, linear-time heuristics such as BLAST are used. Spaced seeds are much more sensitive than the consecutive seed of BLAST and using several seeds represents the current state of the art in approximate search for biological sequences. The most important aspect is computing highly sensitive seeds. Since the problem seems hard, heuristic algorithms are used. The leading software in the common Bernoulli model is the SpEED program. Findings SpEED uses a hill climbing method based on the overlap complexity heuristic. We propose a new algorithm for this heuristic that improves its speed by over one order of magnitude. We use the new implementation to compute improved seeds for several software programs. We compute as well multiple seeds of the same weight as MegaBLAST, that greatly improve its sensitivity. Conclusion Multiple spaced seeds are being successfully used in bioinformatics software programs. Enabling researchers to compute very fast high quality seeds will help expanding the range of their applications.

  19. Kauri seeds and larval somersaults

    DEFF Research Database (Denmark)

    Dupont, Steen Thorleif

    2012-01-01

    The trunk morphology of the larvae of the kauri pine (Agathis) seed infesting moth Agathiphaga is described using conventional, polarization, and scanning electron microscopy. The pine seed chamber formed by the larva is also described and commented on. The simple larval chaetotaxy includes more ...

  20. Banking Wyoming big sagebrush seeds

    Science.gov (United States)

    Robert P. Karrfalt; Nancy Shaw

    2013-01-01

    Five commercially produced seed lots of Wyoming big sagebrush (Artemisia tridentata Nutt. var. wyomingensis (Beetle & Young) S.L. Welsh [Asteraceae]) were stored under various conditions for 5 y. Purity, moisture content as measured by equilibrium relative humidity, and storage temperature were all important factors to successful seed storage. Our results indicate...

  1. Flow characteristics of curved ducts

    Directory of Open Access Journals (Sweden)

    Rudolf P.

    2007-10-01

    Full Text Available Curved channels are very often present in real hydraulic systems, e.g. curved diffusers of hydraulic turbines, S-shaped bulb turbines, fittings, etc. Curvature brings change of velocity profile, generation of vortices and production of hydraulic losses. Flow simulation using CFD techniques were performed to understand these phenomena. Cases ranging from single elbow to coupled elbows in shapes of U, S and spatial right angle position with circular cross-section were modeled for Re = 60000. Spatial development of the flow was studied and consequently it was deduced that minor losses are connected with the transformation of pressure energy into kinetic energy and vice versa. This transformation is a dissipative process and is reflected in the amount of the energy irreversibly lost. Least loss coefficient is connected with flow in U-shape elbows, biggest one with flow in Sshape elbows. Finally, the extent of the flow domain influenced by presence of curvature was examined. This isimportant for proper placement of mano- and flowmeters during experimental tests. Simulations were verified with experimental results presented in literature.

  2. Improved capacitive melting curve measurements

    International Nuclear Information System (INIS)

    Sebedash, Alexander; Tuoriniemi, Juha; Pentti, Elias; Salmela, Anssi

    2009-01-01

    Sensitivity of the capacitive method for determining the melting pressure of helium can be enhanced by loading the empty side of the capacitor with helium at a pressure nearly equal to that desired to be measured and by using a relatively thin and flexible membrane in between. This way one can achieve a nanobar resolution at the level of 30 bar, which is two orders of magnitude better than that of the best gauges with vacuum reference. This extends the applicability of melting curve thermometry to lower temperatures and would allow detecting tiny anomalies in the melting pressure, which must be associated with any phenomena contributing to the entropy of the liquid or solid phases. We demonstrated this principle in measurements of the crystallization pressure of isotopic helium mixtures at millikelvin temperatures by using partly solid pure 4 He as the reference substance providing the best possible universal reference pressure. The achieved sensitivity was good enough for melting curve thermometry on mixtures down to 100 μK. Similar system can be used on pure isotopes by virtue of a blocked capillary giving a stable reference condition with liquid slightly below the melting pressure in the reference volume. This was tested with pure 4 He at temperatures 0.08-0.3 K. To avoid spurious heating effects, one must carefully choose and arrange any dielectric materials close to the active capacitor. We observed some 100 pW loading at moderate excitation voltages.

  3. Classical optics and curved spaces

    International Nuclear Information System (INIS)

    Bailyn, M.; Ragusa, S.

    1976-01-01

    In the eikonal approximation of classical optics, the unit polarization 3-vector of light satisfies an equation that depends only on the index, n, of refraction. It is known that if the original 3-space line element is d sigma 2 , then this polarization direction propagates parallely in the fictitious space n 2 d sigma 2 . Since the equation depends only on n, it is possible to invent a fictitious curved 4-space in which the light performs a null geodesic, and the polarization 3-vector behaves as the 'shadow' of a parallely propagated 4-vector. The inverse, namely, the reduction of Maxwell's equation, on a curve 'dielectric free) space, to a classical space with dielectric constant n=(-g 00 ) -1 / 2 is well known, but in the latter the dielectric constant epsilon and permeability μ must also equal (-g 00 ) -1 / 2 . The rotation of polarization as light bends around the sun by utilizing the reduction to the classical space, is calculated. This (non-) rotation may then be interpreted as parallel transport in the 3-space n 2 d sigma 2 [pt

  4. Vigor of sunflower and soybean aging seed

    OpenAIRE

    Tatić M.; Balešević-Tubić S.; Ðorđević V.; Miklič V.; Vujaković M.; Ðukić V.

    2012-01-01

    Seed aging and deterioration affect seed vigor and viability. The characteristics of the chemical composition of oil crops seed are related to specific processes occurring in the seed during storage. This study was performed to examine the changes in seed vigor of different sunflower and soybean genotypes under controlled and conventional (uncontrolled) conditions of natural aging for six and twelve months. Obtained results show that the degree of seed dama...

  5. Superação da dormência de sementes de carrapicho-beiço-de-boi Dormancy overcoming in Desmodium tortuosum seeds

    Directory of Open Access Journals (Sweden)

    Cibele C. Martins

    1997-01-01

    220 e debulha mecânica, empregando-se processa dor, podem ser recomendados para a superação da dormência e promoção da germinação de sementes de D. tortuosum.In order to obtain a process capable of speeding the germination of D. tortuosum (Sw. DC. seeds, two experiments were conducted with one-seeded loment (control segments submitted to manual threshing; manual threshing followed by chemical scarification, also manual, with sandpaper no 220; mechanical threshing (home processor; chemical scarification with H,S0, (95% for 1, 5, and 8 min; pre-heating at 530C for 4, 10, and 16 h in forced-air oven; imbibition with H2O at 800C for 1, 3, 5, and 10 min; H20 at 27 C for 2 h; and imbibition with thermal swich (H2O at 80 0C/5 min an d H20 at 130 C/ 1 min . For treat ment evaluation one used germination (G, soil seed ling emergence (E , first count of germination (FG, and emergence (FE tests, germination (I. V.G. and emergence (I. V.E. seed index, and seed ling length (S L. A completely randomized block design with 4 replications of 100 (G, FG, I.V. G. or 20 seeds (SL per treatment in the first experiment, and 4 replications of 50 (G, FG, I.V.G. or 100 seeds (E, FE, I. V.E. per treatment on the second experiment was used. In the first experiment, the treatments which showed a significant dormancy decrease (D and consequent germination increase (G in comparison with the control (D = 82%; G =15% were, in a decreasing efficacy order: manual threshing and scarification (D=3%; G=92%, mechanical thre shing (D = 13%; G = 81%, imbibition in H20 at 800C for 1 min (D = 68%; G = 29% and 3 min (D=65%; G=32%. The second experiment (control with D = 93%; G = 3% pointed out: threshing and manual scarification (D=2%; G=93%, mechanical threshing (D = 2%; G = 87%, imbibition into H20 at 800C for 5min and thermal switch (both with D = 85% and G=11%. The FC, I.V.G ., I.V. E., SL, and E vigour tests confirmed these results. Thus, manual scarification with 220 sandpaper and mechanical

  6. Quantifying spatial variability of AgI cloud seeding benefits and Ag enrichments in snow

    Science.gov (United States)

    Fisher, J.; Benner, S. G.; Lytle, M. L.; Kunkel, M. L.; Blestrud, D.; Holbrook, V. P.; Parkinson, S.; Edwards, R.

    2016-12-01

    Glaciogenic cloud seeding is an important scientific technology for enhancing water resources across in the Western United States. Cloud seeding enriches super cooled liquid water layers with plumes of silver iodide (AgI), an artificial ice nuclei. Recent studies using target-control regression analysis and modeling estimate glaciogenic cloud seeding increases snow precipitation between 3-15% annually. However, the efficacy of cloud seeding programs is difficult to assess using weather models and statistics alone. This study will supplement precipitation enhancement statistics and Weather Research and Forecasting (WRF) model outputs with ultra-trace chemistry. Combining precipitation enhancement estimates with trace chemistry data (to estimate AgI plume targeting accuracy) may provide a more robust analysis. Precipitation enhancement from the 2016 water year will be modeled two ways. First, by using double-mass curve. Annual SNOTEL data of the cumulative SWE in unseeded areas and cumulative SWE in seeded areas will be compared before, and after, the cloud seeding program's initiation in 2003. Any change in the double-mass curve's slope after 2003 may be attributed to cloud seeding. Second, WRF model estimates of precipitation will be compared to the observed precipitation at SNOTEL sites. The difference between observed and modeled precipitation in AgI seeded regions may also be attributed to cloud seeding (assuming modeled and observed data are comparable at unseeded SNOTEL stations). Ultra-trace snow chemistry data from the 2016 winter season will be used to validate whether estimated precipitation increases are positively correlated with the mass of silver in the snowpack.

  7. Atlas of stress-strain curves

    CERN Document Server

    2002-01-01

    The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...

  8. Transition curves for highway geometric design

    CERN Document Server

    Kobryń, Andrzej

    2017-01-01

    This book provides concise descriptions of the various solutions of transition curves, which can be used in geometric design of roads and highways. It presents mathematical methods and curvature functions for defining transition curves. .

  9. Comparison and evaluation of mathematical lactation curve ...

    African Journals Online (AJOL)

    p2492989

    A mathematical model of the lactation curve provides summary information about culling and milking strategies ..... Table 2 Statistics of the edited data for first lactation Holstein cows ..... Application of different models to the lactation curves of.

  10. Wheat seed system in Ethiopia: Farmers' varietal perception, seed sources, and seed management

    NARCIS (Netherlands)

    Bishaw, Z.; Struik, P.C.; Gastel, van A.J.G.

    2010-01-01

    Knowledge and information on farmers' perception and its influence on adoption of modern wheat varieties, awareness and source of new wheat production technology, wheat seed sources, and on-farm seed-management practices remain sporadic in Ethiopia. This study was conducted to understand the

  11. Farmer’s seed sources and seed quality: 2. seed health

    NARCIS (Netherlands)

    Bishaw, Z.; Struik, P.C.; Gastel, van A.J.G.

    2013-01-01

    The study assessed the health quality of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) seed samples collected from formal and informal sector in Ethiopia and Syria. In Ethiopia, several seed-borne fungi were found on wheat samples: Cochliobolus sativum, Fusarium avenaceum, F.

  12. Size, physiological quality, and green seed occurrence influenced by seeding rate in soybeans

    Directory of Open Access Journals (Sweden)

    André Sampaio Ferreira

    2017-05-01

    Full Text Available The seeding rate influences the intraspecific competition, which might affect the development and quality of seeds in soybean. However, the impact of seeding rate on the physical and physiological qualities of soybean seeds needs to be better elucidated. This study aimed to evaluate the effects of soybean plant density on the seed size as well as the effects of the interaction between the plant density and seed size on the seed mass, green seed occurence, and physiological seed quality. The experiments were carried out in the growing seasons of the years 2013/14 and 2014/15 in a Latossolo Vermelho distroférrico, under a randomized complete block design, using the NK 7059 RR cultivar with six replications. Four plant densities (150, 300, 440, and 560 thousand viable seeds ha–1 were evaluated. After the classification of seeds into four sizes, using a set of sieves, a 4 ×4 factorial scheme was used for the statistical analysis of the four plant densities and four seed sizes. The seed samples were evaluated for the seed mass, green seed percentage, germination, and vigor. Under thermal and water stress during seed development, an increase in the seeding rate led to a reduction in the green seed occurrence and an increase in the seed size and mass. However, in the absence of thermal and water stress, the seed size and mass were not altered by the seeding rate and, there was no occurrence of green seeds.

  13. Wheat and barley seed systems in Ethiopia and Syria

    NARCIS (Netherlands)

    Bishaw, Z.

    2004-01-01

    Keywords: Wheat,Triticumspp., Barley,Hordeumvulgare L., Seed Systems, Formal Seed Sector, Informal Seed Sector, National Seed Program, Seed Source, Seed Selection, Seed Management, Seed Quality,

  14. AtMyb7, a subgroup 4 R2R3 Myb, negatively regulates ABA-induced inhibition of seed germination by blocking the expression of the bZIP transcription factor ABI5

    KAUST Repository

    Kim, Junhyeok; Hyun, Wooyoung; Nguyen, Hoai Nguyen; Jeong, Chanyoung; Xiong, Liming; Hong, Sukwhan; Lee, Hojoung

    2014-01-01

    Various Myb proteins have been shown to play crucial roles in plants, including primary and secondary metabolism, determination of cell fate and identity, regulation of development and involvement in responses to biotic and abiotic stresses. The 126 R2R3 Myb proteins (with two Myb repeats) have been found in Arabidopsis; however, the functions of most of these proteins remain to be fully elucidated. In the present study, we characterized the function of AtMyb7 using molecular biological and genetic analyses. We used qRT-PCR to determine the levels of stress-response gene transcripts in wild-type and atmyb7 plants. We showed that ArabidopsisAtMyb7 plays a critical role in seed germination. Under abscisic acid (ABA) and high-salt stress conditions, atmyb7 plants showed a lower germination rate than did wild-type plants. Furthermore, AtMyb7 promoter:GUS seeds exhibited different expression patterns in response to variations in the seed imbibition period. AtMyb7 negatively controls the expression of the gene encoding bZIP transcription factor, ABI5, which is a key transcription factor in ABA signalling and serves as a crucial regulator of germination inhibition in Arabidopsis. © 2014 John Wiley & Sons Ltd.

  15. AtMyb7, a subgroup 4 R2R3 Myb, negatively regulates ABA-induced inhibition of seed germination by blocking the expression of the bZIP transcription factor ABI5

    KAUST Repository

    Kim, Junhyeok

    2014-08-27

    Various Myb proteins have been shown to play crucial roles in plants, including primary and secondary metabolism, determination of cell fate and identity, regulation of development and involvement in responses to biotic and abiotic stresses. The 126 R2R3 Myb proteins (with two Myb repeats) have been found in Arabidopsis; however, the functions of most of these proteins remain to be fully elucidated. In the present study, we characterized the function of AtMyb7 using molecular biological and genetic analyses. We used qRT-PCR to determine the levels of stress-response gene transcripts in wild-type and atmyb7 plants. We showed that ArabidopsisAtMyb7 plays a critical role in seed germination. Under abscisic acid (ABA) and high-salt stress conditions, atmyb7 plants showed a lower germination rate than did wild-type plants. Furthermore, AtMyb7 promoter:GUS seeds exhibited different expression patterns in response to variations in the seed imbibition period. AtMyb7 negatively controls the expression of the gene encoding bZIP transcription factor, ABI5, which is a key transcription factor in ABA signalling and serves as a crucial regulator of germination inhibition in Arabidopsis. © 2014 John Wiley & Sons Ltd.

  16. Gelfond–Bézier curves

    KAUST Repository

    Ait-Haddou, Rachid; Sakane, Yusuke; Nomura, Taishin

    2013-01-01

    We show that the generalized Bernstein bases in Müntz spaces defined by Hirschman and Widder (1949) and extended by Gelfond (1950) can be obtained as pointwise limits of the Chebyshev–Bernstein bases in Müntz spaces with respect to an interval [a,1][a,1] as the positive real number a converges to zero. Such a realization allows for concepts of curve design such as de Casteljau algorithm, blossom, dimension elevation to be transferred from the general theory of Chebyshev blossoms in Müntz spaces to these generalized Bernstein bases that we termed here as Gelfond–Bernstein bases. The advantage of working with Gelfond–Bernstein bases lies in the simplicity of the obtained concepts and algorithms as compared to their Chebyshev–Bernstein bases counterparts.

  17. Bubble Collision in Curved Spacetime

    International Nuclear Information System (INIS)

    Hwang, Dong-il; Lee, Bum-Hoon; Lee, Wonwoo; Yeom, Dong-han

    2014-01-01

    We study vacuum bubble collisions in curved spacetime, in which vacuum bubbles were nucleated in the initial metastable vacuum state by quantum tunneling. The bubbles materialize randomly at different times and then start to grow. It is known that the percolation by true vacuum bubbles is not possible due to the exponential expansion of the space among the bubbles. In this paper, we consider two bubbles of the same size with a preferred axis and assume that two bubbles form very near each other to collide. The two bubbles have the same field value. When the bubbles collide, the collided region oscillates back-and-forth and then the collided region eventually decays and disappears. We discuss radiation and gravitational wave resulting from the collision of two bubbles

  18. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  19. Gelfond–Bézier curves

    KAUST Repository

    Ait-Haddou, Rachid

    2013-02-01

    We show that the generalized Bernstein bases in Müntz spaces defined by Hirschman and Widder (1949) and extended by Gelfond (1950) can be obtained as pointwise limits of the Chebyshev–Bernstein bases in Müntz spaces with respect to an interval [a,1][a,1] as the positive real number a converges to zero. Such a realization allows for concepts of curve design such as de Casteljau algorithm, blossom, dimension elevation to be transferred from the general theory of Chebyshev blossoms in Müntz spaces to these generalized Bernstein bases that we termed here as Gelfond–Bernstein bases. The advantage of working with Gelfond–Bernstein bases lies in the simplicity of the obtained concepts and algorithms as compared to their Chebyshev–Bernstein bases counterparts.

  20. Sibling curves of quadratic polynomials | Wiggins | Quaestiones ...

    African Journals Online (AJOL)

    Sibling curves were demonstrated in [1, 2] as a novel way to visualize the zeroes of real valued functions. In [3] it was shown that a polynomial of degree n has n sibling curves. This paper focuses on the algebraic and geometric properites of the sibling curves of real and complex quadratic polynomials. Key words: Quadratic ...

  1. GLOBAL AND STRICT CURVE FITTING METHOD

    NARCIS (Netherlands)

    Nakajima, Y.; Mori, S.

    2004-01-01

    To find a global and smooth curve fitting, cubic B­Spline method and gathering­ line methods are investigated. When segmenting and recognizing a contour curve of character shape, some global method is required. If we want to connect contour curves around a singular point like crossing points,

  2. Trigonometric Characterization of Some Plane Curves

    Indian Academy of Sciences (India)

    IAS Admin

    (Figure 1). A relation between tan θ and tanψ gives the trigonometric equation of the family of curves. In this article, trigonometric equations of some known plane curves are deduced and it is shown that these equations reveal some geometric characteristics of the families of the curves under consideration. In Section 2,.

  3. M-curves and symmetric products

    Indian Academy of Sciences (India)

    Indranil Biswas

    2017-08-03

    Aug 3, 2017 ... is bounded above by g + 1, where g is the genus of X [11]. Curves which have exactly the maximum number (i.e., genus +1) of components of the real part are called M-curves. Classifying real algebraic curves up to homeomorphism is straightforward, however, classifying even planar non-singular real ...

  4. Holomorphic curves in exploded manifolds: Kuranishi structure

    OpenAIRE

    Parker, Brett

    2013-01-01

    This paper constructs a Kuranishi structure for the moduli stack of holomorphic curves in exploded manifolds. To avoid some technicalities of abstract Kuranishi structures, we embed our Kuranishi structure inside a moduli stack of curves. The construction also works for the moduli stack of holomorphic curves in any compact symplectic manifold.

  5. Automated Blazar Light Curves Using Machine Learning

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Spencer James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-27

    This presentation describes a problem and methodology pertaining to automated blazar light curves. Namely, optical variability patterns for blazars require the construction of light curves and in order to generate the light curves, data must be filtered before processing to ensure quality.

  6. A system for generating virtual seeds

    Directory of Open Access Journals (Sweden)

    Sako Y.

    1998-01-01

    Full Text Available Seed analysts need to identify seeds, and seed catalogs are used as a reference to accomplish this task. Conventional seed catalogs supply two-dimensional photographs and hand-drawn diagrams. In this study, a new, three-dimensional representation of seeds is developed to supplement these traditional photographs and drawings. QuickTime VR is a promising method for viewing three-dimensional objects on a computer screen. It permits manipulation of an object by rotating and viewing it from any pre-specified angle at an interactive speed, allowing the viewer the sense of examining a hand-held object. In this study, QuickTime VR object movies of seeds were created as interactive "movies" of seeds that can be rotated and scaled to give the viewer the sensation of examining actual seeds. This approach allows the examination of virtual seeds from any angle, permitting more accurate identification of seeds by seed analysts.

  7. Distributed seeding for narrow-line width hard x-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Anisimov, Petr Mikhaylovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, IV, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marksteiner, Quinn R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg crystal monochromators to enhance the spectral brightness of the MaRIE hard X-ray freeelectron laser. DS differs from self-seeding in three important aspects. First, DS relies on spectral filtering of the radiation at multiple locations along the undulator, with a monochromator located every few power gain lengths. Second, DS performs filtering early in the exponential gain region before SASE spikes start to appear in the radiation longitudinal profile. Third, DS provides the option to select a wavelength longer than the peak of the SASE gain curve, which leads to improved spectral contrast of the seeded FEL over the SASE background. Timedependent Genesis simulations show the power-vs-z growth curves for DS exhibit behaviors of a seeded FEL amplifier, such as exponential growth region immediately after the filters. Of the seeding approaches considered, the two-stage DS spectra produce the highest contrast of seeded FEL over the SASE background and that the three-stage DS provides the narrowest linewidth with a relative spectral FWHM of 8 X 10-5 .

  8. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    International Nuclear Information System (INIS)

    Wang Ting; Li Fanghua; Liu Qingfang; Bian Po; Wang Jufang; Wu Yuejin; Wu Lijun; Li Wenjian

    2012-01-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and γ-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  9. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ting [University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026 (China); Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Fanghua [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Liu Qingfang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Bian Po, E-mail: bianpo@ipp.ac.cn [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Wang Jufang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Wu Yuejin; Wu Lijun [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Wenjian [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China)

    2012-09-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and {gamma}-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  10. Seed selection by earthworms : chemical seed properties matter more than morphological traits

    OpenAIRE

    Clause, J.; Forey, E.; Eisenhauer, N.; Seal, C.E.; Soudey, A.; Colville, L.; Barot, Sébastien

    2017-01-01

    Aims : The passage of seeds through the earthworm gut potentially damages seeds, altering seed and seedling performances depending on seed traits. This work was conducted to study to what extent chemical and morphological seed traits determine the seed attractiveness for earthworms. Methods : We tested seed selection via the ingestion and digestion of 23 grassland plant species spanning a range of 14 morphological and chemical traits by two common earthworm species: the anecic Lumbricus te...

  11. Study of isodose curves of an eye brachytherapy plaque

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Marcos R.O.; Mourao, Arnaldo P., E-mail: marcos.robertto@hotmail.com, E-mail: seg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Grynberg, Suely E., E-mail: aprata@des.cefetmg.br [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar

    2015-07-01

    The use eye plaque brachytherapy for intraocular tumors treatment is a process designed to protect healthy eye structures, as well as visual functions. It replaces enucleation when possible. The knowledge of the dose spatial distribution inside the eyeball and adjacent structures is very important to obtain the therapeutic dose, minimize the side effects and ensure efficiency in the process. Small variations in positioning the plaque on the ocular surface may generate a less effective treatment. Thus, in this work an eyeball phantom and a seed accommodation system similar to a commercially eye plaque model ROPES with diameter of 15 mm, were developed both in solid water Gammex 457 to conduct the study of the possible variation in the dose deposition inside the eye phantom. Radiochromic films were used to record isodose curves of two orthogonal plans within the simulator. The results showed that there is a difference in the dose deposition for the two orthogonal plans studied. This difference is 8.33% higher for the maximum dose value. Thus, a difference in dose that occurs due to the asymmetrical distribution of seeds on the eye plaque may interfere with the treatment, making it less effective. (author)

  12. Study of isodose curves of an eye brachytherapy plaque

    International Nuclear Information System (INIS)

    Costa, Marcos R.O.; Mourao, Arnaldo P.; Grynberg, Suely E.

    2015-01-01

    The use eye plaque brachytherapy for intraocular tumors treatment is a process designed to protect healthy eye structures, as well as visual functions. It replaces enucleation when possible. The knowledge of the dose spatial distribution inside the eyeball and adjacent structures is very important to obtain the therapeutic dose, minimize the side effects and ensure efficiency in the process. Small variations in positioning the plaque on the ocular surface may generate a less effective treatment. Thus, in this work an eyeball phantom and a seed accommodation system similar to a commercially eye plaque model ROPES with diameter of 15 mm, were developed both in solid water Gammex 457 to conduct the study of the possible variation in the dose deposition inside the eye phantom. Radiochromic films were used to record isodose curves of two orthogonal plans within the simulator. The results showed that there is a difference in the dose deposition for the two orthogonal plans studied. This difference is 8.33% higher for the maximum dose value. Thus, a difference in dose that occurs due to the asymmetrical distribution of seeds on the eye plaque may interfere with the treatment, making it less effective. (author)

  13. Method of construction spatial transition curve

    Directory of Open Access Journals (Sweden)

    S.V. Didanov

    2013-04-01

    Full Text Available Purpose. The movement of rail transport (speed rolling stock, traffic safety, etc. is largely dependent on the quality of the track. In this case, a special role is the transition curve, which ensures smooth insertion of the transition from linear to circular section of road. The article deals with modeling of spatial transition curve based on the parabolic distribution of the curvature and torsion. This is a continuation of research conducted by the authors regarding the spatial modeling of curved contours. Methodology. Construction of the spatial transition curve is numerical methods for solving nonlinear integral equations, where the initial data are taken coordinate the starting and ending points of the curve of the future, and the inclination of the tangent and the deviation of the curve from the tangent plane at these points. System solutions for the numerical method are the partial derivatives of the equations of the unknown parameters of the law of change of torsion and length of the transition curve. Findings. The parametric equations of the spatial transition curve are calculated by finding the unknown coefficients of the parabolic distribution of the curvature and torsion, as well as the spatial length of the transition curve. Originality. A method for constructing the spatial transition curve is devised, and based on this software geometric modeling spatial transition curves of railway track with specified deviations of the curve from the tangent plane. Practical value. The resulting curve can be applied in any sector of the economy, where it is necessary to ensure a smooth transition from linear to circular section of the curved space bypass. An example is the transition curve in the construction of the railway line, road, pipe, profile, flat section of the working blades of the turbine and compressor, the ship, plane, car, etc.

  14. Effects of seed fermentation method on seed germination and vigor ...

    African Journals Online (AJOL)

    BERTIN

    2013-11-27

    Nov 27, 2013 ... methods (fermented in ambient air, plastic bag stored in ambient or in plastic bag buried) were tested ... fruits into plastic bag that was exposed in ambient air in the field; SFD, seeds ..... Concepts and technologies of selected.

  15. Improving the traditional sesame seed planting with seed pelleting

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... 1Department of Agricultural Machinery, Faculty of Agriculture, Adnan Menderes University, Turkey. 2Fethiye ... the pelleted sesame seeds improved the yield significantly ... Sesame holds a special importance in the world's oil.

  16. Laser treatment of radish seed

    International Nuclear Information System (INIS)

    Kartalov, P.; Nidal, T.

    1987-01-01

    Trials were conducted in unheated plastic greenhouses in 1985-1986 to test the effect of laser treatment on radish seed. Seed of cv Saxia was irradiated with helio-neon laser of 632.8 Nm wave length at: 2-, 4- and 6-fold irradiation. Results showed that plants of all variants emerged almost simultaneously. The root mass was greatest for plants obtained from 4-fold irradiated seed. Treatment enhanced root production in 1985, and in 1986 4-fold irradiation boosted yield by 15%

  17. Monte Carlo calculation of dosimetric parameters of a {sup 125}I brachytherapy seed encapsulation with biocompatible polymer and a ceramic matrix as radiographic marker

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lucas P.; Santos, Adriano M.; Grynberg, Suely E., E-mail: lpr@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Dosimetria e Simulacao Computacional; Facure, Alessandro, E-mail: facure@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    For prostate cancer treatments, there is an increasing interest in the permanent radioactive seeds implant technique. Currently, in Brazil, the seeds are imported at high prices, which prohibit their use in public hospitals. One of the seed models that have been developed at CDTN has a ceramic matrix as a radioisotope carrier and a radiographic marker; the seed is encapsulated with biocompatible polymer. In this work, Monte Carlo simulations were performed in order to assess the dose distributions generated by the prototype seed model. The obtained data was assessed as described in the TG-43U1 report by the AAPM. The dosimetric parameters dose rate constant, {Lambda}, radial dose function, g{sub L}(r), and anisotropy function, F(r,{theta}), were derived from simulations using the MCNP5 code. The function g(r) shows that the seed has a lower decrease in dose rate on its transverse axis when compared to the 6711 model (one of the most used seeds in permanent prostate implants). F(r,{theta}) shows that CDTN's seed anisotropy curves are smoother than the 6711 model curves for {theta}{<=}20 deg and 0.25{<=}r{<=}1 cm. As well, the {Lambda} value is 15% lower than the {Lambda} value of 6711. The results show that CDTN's seed model can deposit a more isotropic dose. Because of the model's characteristics, the seeds can be impregnated with iodine of lower specific activity which would help reducing costs. (author)

  18. Metodologia para a avaliação do vigor de sementes de tomate Methodology for the evaluation of tomato seed vigor

    Directory of Open Access Journals (Sweden)

    Cibele C Martins

    2006-09-01

    °C and evaluations after 2, 4, 6, 8, and 24 hours of imbibition. The germination percentage and vigor tests of primary root emission (after 56 and 72 hours and electrical conductivity were correlated with seedling emergence. However, only the electrical conductivity test after 24 hours of imbibition showed efficiency to evaluate vigor of tomato seeds taking similar information to seedling emergence.

  19. Power forward curves: a managerial perspective

    International Nuclear Information System (INIS)

    Nagarajan, Shankar

    1999-01-01

    This chapter concentrates on managerial application of power forward curves, and examines the determinants of electricity prices such as transmission constraints, its inability to be stored in a conventional way, its seasonality and weather dependence, the generation stack, and the swing risk. The electricity forward curve, classical arbitrage, constructing a forward curve, volatilities, and electricity forward curve models such as the jump-diffusion model, the mean-reverting heteroscedastic volatility model, and an econometric model of forward prices are examined. A managerial perspective of the applications of the forward curve is presented covering plant valuation, capital budgeting, performance measurement, product pricing and structuring, asset optimisation, valuation of transmission options, and risk management

  20. Retrograde curves of solidus and solubility

    International Nuclear Information System (INIS)

    Vasil'ev, M.V.

    1979-01-01

    The investigation was concerned with the constitutional diagrams of the eutectic type with ''retrograde solidus'' and ''retrograde solubility curve'' which must be considered as diagrams with degenerate monotectic transformation. The solidus and the solubility curves form a retrograde curve with a common retrograde point representing the solubility maximum. The two branches of the Aetrograde curve can be described with the aid of two similar equations. Presented are corresponding equations for the Cd-Zn system and shown is the possibility of predicting the run of the solubility curve

  1. The writhe of open and closed curves

    International Nuclear Information System (INIS)

    Berger, Mitchell A; Prior, Chris

    2006-01-01

    Twist and writhe measure basic geometric properties of a ribbon or tube. While these measures have applications in molecular biology, materials science, fluid mechanics and astrophysics, they are under-utilized because they are often considered difficult to compute. In addition, many applications involve curves with endpoints (open curves); but for these curves the definition of writhe can be ambiguous. This paper provides simple expressions for the writhe of closed curves, and provides a new definition of writhe for open curves. The open curve definition is especially appropriate when the curve is anchored at endpoints on a plane or stretches between two parallel planes. This definition can be especially useful for magnetic flux tubes in the solar atmosphere, and for isotropic rods with ends fixed to a plane

  2. Seed cryopreservation of Fraxinus angustifolia Vahl

    African Journals Online (AJOL)

    Università

    2013-04-17

    control) and liquid nitrogen-treated seeds were .... 76.0 ± 4.0 (NT in GA3), with an intermediary value of 70.0. ± 5.0% (Cryo seeds in water .... in November, suggesting a loss of dormancy during seed maturation. Furthermore, seed ...

  3. Storage requirements for sugar maple seeds

    Science.gov (United States)

    Harry W. Yawney; Clayton M., Jr. Carl

    1974-01-01

    Sugar maple seeds, collected from three trees in northern Vermont, were stored at four temperatures (18, 7, 2, and -10ºC) in combination with four seed moisture contents (35, 25, 17, and 10 percent). Seed moisture content and storage temperature significantly affected keeping ability, and these factors were highly interrelated. Seeds from all trees kept best...

  4. 7 CFR 948.6 - Seed potatoes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Seed potatoes. 948.6 Section 948.6 Agriculture... and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN COLORADO Order Regulating Handling Definitions § 948.6 Seed potatoes. Seed potatoes or seed means any potatoes...

  5. 7 CFR 201.57 - Hard seeds.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard at the end of the prescribed test because they have not absorbed water, due to an impermeable seed coat... percentage of germination. For flatpea, continue the swollen seed in test for 14 days when germinating at 15...

  6. Brassica rapa L. seed development in hypergravity

    NARCIS (Netherlands)

    Musgrave, M.E.; Kuang, A.; Allen, J.; Blasiak, J.; van Loon, J.J.W.A.

    2009-01-01

    Previous experiments had shown that microgravity adversely affected seed development in Brassica rapa L. We tested the hypothesis that gravity controls seed development via modulation of gases around the developing seeds, by studying how hypergravity affects the silique microenvironment and seed

  7. Evaluation of Lettuce Genotypes for Seed Thermotolerance

    Science.gov (United States)

    Thermoinhibition of lettuce (Lactuca sativa L.) seed germination is a common problem associated with lettuce production. Depending on lettuce cultivars, seed germination may be inhibited when temperatures exceed 28oC. The delay or inhibition of seed germination at high temperatures may reduce seedli...

  8. Analysis of seed quality in NS sunflower hybrid seed processed between 2010 and 2014

    Directory of Open Access Journals (Sweden)

    Jokić Goran

    2015-01-01

    Full Text Available This paper analyzed the processed seed of five sunflower hybrid seed developed at the Institute of Field and Vegetable Crops in Novi Sad. The cultivars were Rimi PR, Duško, NS Dukat, Sumo 1 PR and Sremac. The analysis was conducted on seed lots processed between 2010 and 2014 and involved the following parameters: seed purity percentage, 1000-seed weight, germination energy, germination, seed moisture, number of weed seeds per 1000 grams of seed. The results of the study produced the following average values: seed purity - 99.72%, 1000-seed weight - 67.59g, germination energy - 88.2%, germination - 91.8%, seed moisture - 8.3%. There were not found weeds seeds as well as pathogens on the seed samples, these values are all within the legally prescribed limits.

  9. Autoradiography for iodine-125 seeds

    International Nuclear Information System (INIS)

    Alberti, W.; Divoux, S.; Pothmann, B.; Tabor, P.; Hermann, K.P.; Harder, D.

    1993-01-01

    To study the interior design of model 6702 and 6711 iodine-125 seeds, contact autoradiographs were performed using mammography film. Improved resolution was obtained using a pin-hole camera with a hole of 0.1 mm x 0.1 mm. With these techniques, qualitative determination of the relative activity distribution within each seed was possible. The number of the activated resin spheres and the positions of the centers of these spheres can be exactly determined. A model calculation shows that variations in the arrangement of the activated spheres within a seed have a moderate influence on the dose distribution at source distances below 10 mm. Knowing the exact source configuration may be useful when comparing dose calculations with measured data for model 6702 125 I seeds which are currently employed in ophthalmic plaque and implant therapy of other tumors. 16 refs., 5 figs., 2 tabs

  10. Ethylene, seed germination, and epinasty.

    Science.gov (United States)

    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.

  11. Topology of large-scale structure in seeded hot dark matter models

    Science.gov (United States)

    Beaky, Matthew M.; Scherrer, Robert J.; Villumsen, Jens V.

    1992-01-01

    The topology of the isodensity surfaces in seeded hot dark matter models, in which static seed masses provide the density perturbations in a universe dominated by massive neutrinos is examined. When smoothed with a Gaussian window, the linear initial conditions in these models show no trace of non-Gaussian behavior for r0 equal to or greater than 5 Mpc (h = 1/2), except for very low seed densities, which show a shift toward isolated peaks. An approximate analytic expression is given for the genus curve expected in linear density fields from randomly distributed seed masses. The evolved models have a Gaussian topology for r0 = 10 Mpc, but show a shift toward a cellular topology with r0 = 5 Mpc; Gaussian models with an identical power spectrum show the same behavior.

  12. Path integrals on curved manifolds

    International Nuclear Information System (INIS)

    Grosche, C.; Steiner, F.

    1987-01-01

    A general framework for treating path integrals on curved manifolds is presented. We also show how to perform general coordinate and space-time transformations in path integrals. The main result is that one has to subtract a quantum correction ΔV ∝ ℎ 2 from the classical Lagrangian L, i.e. the correct effective Lagrangian to be used in the path integral is L eff = L-ΔV. A general prescription for calculating the quantum correction ΔV is given. It is based on a canonical approach using Weyl-ordering and the Hamiltonian path integral defined by the midpoint prescription. The general framework is illustrated by several examples: The d-dimensional rotator, i.e. the motion on the sphere S d-1 , the path integral in d-dimensional polar coordinates, the exact treatment of the hydrogen atom in R 2 and R 3 by performing a Kustaanheimo-Stiefel transformation, the Langer transformation and the path integral for the Morse potential. (orig.)

  13. Page curves for tripartite systems

    International Nuclear Information System (INIS)

    Hwang, Junha; Lee, Deok Sang; Nho, Dongju; Oh, Jeonghun; Park, Hyosub; Zoe, Heeseung; Yeom, Dong-han

    2017-01-01

    We investigate information flow and Page curves for tripartite systems. We prepare a tripartite system (say, A , B , and C ) of a given number of states and calculate information and entropy contents by assuming random states. Initially, every particle was in A (this means a black hole), and as time goes on, particles move to either B (this means Hawking radiation) or C (this means a broadly defined remnant, including a non-local transport of information, the last burst, an interior large volume, or a bubble universe, etc). If the final number of states of the remnant is smaller than that of Hawking radiation, then information will be stored by both the radiation and the mutual information between the radiation and the remnant, while the remnant itself does not contain information. On the other hand, if the final number of states of the remnant is greater than that of Hawking radiation, then the radiation contains negligible information, while the remnant and the mutual information between the radiation and the remnant contain information. Unless the number of states of the remnant is large enough compared to the entropy of the black hole, Hawking radiation must contain information; and we meet the menace of black hole complementarity again. Therefore, this contrasts the tension between various assumptions and candidates of the resolution of the information loss problem. (paper)

  14. Vacuum polarization in curved spacetime

    International Nuclear Information System (INIS)

    Guy, R.W.

    1979-01-01

    A necessary step in the process of understanding the quantum theory of gravity is the calculation of the stress-energy tensor of quantized fields in curved space-times. The determination of the stress tensor, a formally divergent object, is made possible in this dissertation by utilizing the zeta-function method of regularization and renormalization. By employing this scheme's representation of the renormalized effective action functional, an expression of the stress tensor for a massless, conformally invariant scalar field, first given by DeWitt, is derived. The form of the renormalized stress tensor is first tested in various examples of flat space-times. It is shown to vanish in Minkowski space and to yield the accepted value of the energy density in the Casimir effect. Next, the stress tensor is calculated in two space-times of constant curvature, the Einstein universe and the deSitter universe, and the results are shown to agree with those given by an expression of the stress tensor that is valid in conformally flat space-times. This work culminates in the determination of the stress tensor on the horizon of a Schwarzschild black hole. This is accomplished by approximating the radial part of the eigen-functions and the metric in the vicinity of the horizon. The stress tensor at this level approximation is found to be pure trace. The approximated forms of the Schwarzschild metric describes a conformally flat space-time that possesses horizons

  15. Lack of caching of direct-seeded Douglas fir seeds by deer mice

    International Nuclear Information System (INIS)

    Sullivan, T.P.

    1978-01-01

    Seed caching by deer mice was investigated by radiotagging seeds in forest and clear-cut areas in coastal British Columbia. Deer mice tend to cache very few Douglas fir seeds in the fall when the seed is uniformly distributed and is at densities comparable with those used in direct-seeding programs. (author)

  16. Seed mass and mast seeding enhance dispersal by a neotropical scatter-hoarding rodent

    NARCIS (Netherlands)

    Jansen, P.A.; Bongers, F.J.J.M.; Hemerik, L.

    2004-01-01

    Many tree species that depend on scatter-hoarding animals for seed dispersal produce massive crops of large seeds at irregular intervals. Mast seeding and large seed size in these species have been explained as adaptations to increase animal dispersal and reduce predation. We studied how seed size

  17. Chloroxyanion residue on seeds and sprouts after chlorine dioxide sanitation of alfalfa seed

    Science.gov (United States)

    The effects of a 6-h chlorine dioxide sanitation of alfalfa seed (0, 50, 100, and 200 mg/kg seed) on total coliform bacteria, seed germination, and on the presence of chlorate and perchlorate residues in seed rinse, seed soak, and in alfalfa sprouts was determined. Chlorate residues in 20000 ppm cal...

  18. Moringa Seed Oils

    Directory of Open Access Journals (Sweden)

    Joana O. Ilesanmi

    2010-01-01

    Full Text Available This study was conducted to determine the effects of neem (Azadirachta indica A. Juss and moringa (Moringa oleifera seed oils on the storability of cowpea grain. Cowpea samples were treated with various concentrations (0.5, 1.0, and 1.5 mL/200 g cowpea of pure neem and moringa oils and their mixtures in ratios of 1:1, 1:2, and 1:3. The treated cowpea samples were stored for 180 days. Data were collected every 30 days on number of eggs laid, total weevil population, and percentage of uninfested grains and analysed statistically. Significantly different means were compared using LSD at <.05. Increasing oil concentration resulted in better cowpea protection, for example, in oviposition where the control had 6513 eggs, only 8 eggs were recorded in pure neem oil-treated sample at 0.5 mL/200 g. Generally, better results were obtained with higher oil concentrations either in their pure forms or mixtures. The control had a total weevil population of 4988, while most treated samples had none. The control samples had 0% uninfested grains, while 73–94% of uninfested grains were observed in treated samples after 6 months of storage. Therefore, mixture of the oils at 1.5 mL/200 g can be effectively used to store cowpea.

  19. Diamond Synthesis Employing Nanoparticle Seeds

    Science.gov (United States)

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)

    2014-01-01

    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  20. Consistent Valuation across Curves Using Pricing Kernels

    Directory of Open Access Journals (Sweden)

    Andrea Macrina

    2018-03-01

    Full Text Available The general problem of asset pricing when the discount rate differs from the rate at which an asset’s cash flows accrue is considered. A pricing kernel framework is used to model an economy that is segmented into distinct markets, each identified by a yield curve having its own market, credit and liquidity risk characteristics. The proposed framework precludes arbitrage within each market, while the definition of a curve-conversion factor process links all markets in a consistent arbitrage-free manner. A pricing formula is then derived, referred to as the across-curve pricing formula, which enables consistent valuation and hedging of financial instruments across curves (and markets. As a natural application, a consistent multi-curve framework is formulated for emerging and developed inter-bank swap markets, which highlights an important dual feature of the curve-conversion factor process. Given this multi-curve framework, existing multi-curve approaches based on HJM and rational pricing kernel models are recovered, reviewed and generalised and single-curve models extended. In another application, inflation-linked, currency-based and fixed-income hybrid securities are shown to be consistently valued using the across-curve valuation method.

  1. Seed governance. From seed aid to seed system security in fragile areas

    NARCIS (Netherlands)

    Rietberg, P.I.; Gevers, H.; Hospes, O.

    2014-01-01

    Intergovernmental agencies and development organizations, including Cordaid, consider interventions directed at seed security of utmost importance to support smallholders recovering from conflict situations and disasters, and to contribute to revitalisation of local agricultural production and food

  2. Optimum harvest maturity for Leymus chinensis seed

    Directory of Open Access Journals (Sweden)

    Jixiang Lin

    2016-06-01

    Full Text Available Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT and accelerated ageing test (AAT. Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest.

  3. Mango seed uses: thermal behaviour of mango seed almond fat and its mixtures with cocoa butter.

    Science.gov (United States)

    Solís-Fuentes, J A; Durán-de-Bazúa, M C

    2004-03-01

    This paper deals with the physicochemical characterization, including thermal behaviour, by differential scanning calorimetry of mango seed almond fat (MAF), alone and in mixtures with cocoa butter (CB). Results showed that mango almond seeds contain about 5.28-11.26% (dw) of fat. The refraction index is 1.466, the saponification index 189.0 and the iodine index 41.76. Fatty acids found in MAF are oleic, stearic, and palmitic acids (40.81%, 39.07% and 9.29% (w/w), respectively) as well as smaller amounts of linoleic, with arachidic, behenic, lignoceric, and linolenic acids, among others. Calorimetric analysis showed that MAF crystallizes between 14.6 and -24.27 degrees C with a DeltaHc of 56.06 J/g and melts between -17.1 and 53.8 degrees C, with fusion maxima at 18.54 degrees C and 40.0 degrees C for the alpha and beta polymorphic forms. Their fusion enthalpies are 70.12 and 115.7 J/g. The MAF solids content profile is very similar to that of CB, both in stabilized and non-stabilized samples. The mixing compatibility was analyzed using isosolids curves of mixtures of different compositions.

  4. Phenolics in the seed coat of wild soybean (Glycine soja) and their significance for seed hardness and seed germination.

    Science.gov (United States)

    Zhou, San; Sekizaki, Haruo; Yang, Zhihong; Sawa, Satoko; Pan, Jun

    2010-10-27

    Hardseededness in annual wild soybean (Glycine soja Sieb. Et Zucc.) is a valuable trait that affects the germination, viability, and quality of stored seeds. Two G. soja ecotypes native to Shandong Province of China have been used to identify the phenolics in the seed coat that correlate with the seed hardness and seed germination. Three major phenolics from the seed coat were isolated and identified as epicatechin, cyanidin 3-O-glucoside, and delphinidin 3-O-glucoside. Of the three phenolics, only the change of epicatechin exhibited a significant positive correlation with the change of hard seed percentages both under different water conditions during seed development and under different gas conditions during seed storage. Epicatechin also reveals a hormesis-like effect on the seed germination of G. soja. Epicatechin is suggested to be functionally related to coat-imposed hardseededness in G. soja.

  5. Construction of calibration curve for accountancy tank

    International Nuclear Information System (INIS)

    Kato, Takayuki; Goto, Yoshiki; Nidaira, Kazuo

    2009-01-01

    Tanks are equipped in a reprocessing plant for accounting solution of nuclear material. The careful measurement of volume in tanks is very important to implement rigorous accounting of nuclear material. The calibration curve relating the volume and level of solution needs to be constructed, where the level is determined by differential pressure of dip tubes. Several calibration curves are usually employed, but it's not explicitly decided how many segment are used, where to select segment, or what should be the degree of polynomial curve. These parameters, i.e., segment and degree of polynomial curve are mutually interrelated to give the better performance of calibration curve. Here we present the construction technique of giving optimum calibration curves and their characteristics. (author)

  6. MICA: Multiple interval-based curve alignment

    Science.gov (United States)

    Mann, Martin; Kahle, Hans-Peter; Beck, Matthias; Bender, Bela Johannes; Spiecker, Heinrich; Backofen, Rolf

    2018-01-01

    MICA enables the automatic synchronization of discrete data curves. To this end, characteristic points of the curves' shapes are identified. These landmarks are used within a heuristic curve registration approach to align profile pairs by mapping similar characteristics onto each other. In combination with a progressive alignment scheme, this enables the computation of multiple curve alignments. Multiple curve alignments are needed to derive meaningful representative consensus data of measured time or data series. MICA was already successfully applied to generate representative profiles of tree growth data based on intra-annual wood density profiles or cell formation data. The MICA package provides a command-line and graphical user interface. The R interface enables the direct embedding of multiple curve alignment computation into larger analyses pipelines. Source code, binaries and documentation are freely available at https://github.com/BackofenLab/MICA

  7. Inverse Diffusion Curves Using Shape Optimization.

    Science.gov (United States)

    Zhao, Shuang; Durand, Fredo; Zheng, Changxi

    2018-07-01

    The inverse diffusion curve problem focuses on automatic creation of diffusion curve images that resemble user provided color fields. This problem is challenging since the 1D curves have a nonlinear and global impact on resulting color fields via a partial differential equation (PDE). We introduce a new approach complementary to previous methods by optimizing curve geometry. In particular, we propose a novel iterative algorithm based on the theory of shape derivatives. The resulting diffusion curves are clean and well-shaped, and the final image closely approximates the input. Our method provides a user-controlled parameter to regularize curve complexity, and generalizes to handle input color fields represented in a variety of formats.

  8. Equilibrium relative humidity as a tool to monitor seed moisture

    Science.gov (United States)

    Robert P. Karrfalt

    2010-01-01

    The importance of seed moisture in maintaining high seed viability is well known. The seed storage chapters in the Tropical Tree Seed Manual (Hong and Ellis 2003) and the Woody Plant Seed Manual (Bonner 2008a) give a detailed discussion and many references on this point. Working with seeds in an operational setting requires a test of seed moisture status. It is...

  9. String Sigma Models on Curved Supermanifolds

    Directory of Open Access Journals (Sweden)

    Roberto Catenacci

    2018-04-01

    Full Text Available We use the techniques of integral forms to analyze the easiest example of two-dimensional sigma models on a supermanifold. We write the action as an integral of a top integral form over a D = 2 supermanifold, and we show how to interpolate between different superspace actions. Then, we consider curved supermanifolds, and we show that the definitions used for flat supermanifolds can also be used for curved supermanifolds. We prove it by first considering the case of a curved rigid supermanifold and then the case of a generic curved supermanifold described by a single superfield E.

  10. Regional Marginal Abatement Cost Curves for NOx

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data underlying the figures included in the manuscript "Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and...

  11. Report on seed born diseases in organic seed and propagation material

    OpenAIRE

    Micheloni, C.; Plakolm, G.; Schärer, H.

    2007-01-01

    The key questions which will be addressed in this report are: • Are seed born diseases an important factor that prevents seed companies from producing organic seeds and organic farmers from using them? • Which seed treatments are available in organic farming? Which treatments are or will be acceptable? To which degree are they effective? • Are the thresholds for seed born diseases different among Member States? Can this cause unfair competition among farmers and seed producers? • ...

  12. Influence of Fungicides Application and Seed Processing on Sunflower Seed Quality

    OpenAIRE

    Šimić, Branimir; Svitlica, Brankica; Ćosić, Jasenka; Andrić, Luka; Rozman, Vlatka; Postić, Jelena; Liović, Ivica

    2009-01-01

    The aim of the research was to determine influence of methods of seed processing and application of fungicides on mass of 1000 seeds, intergrowth energy and seed germination of sunflower hybrids ‘Favorit’ and ‘Apolon’ in 2005 and 2006. Selected untreated seeds of both sunflower hybrids (control) had a minimal mass of 1000 seeds (55-59 g), intergrowth energy (18-37 %) and seed germination (39-52 %). In both years of research maximal seed quality, mass of 1000 seeds (67-69 g), intergrowth energ...

  13. NEW CONCEPTS AND TEST METHODS OF CURVE PROFILE AREA DENSITY IN SURFACE: ESTIMATION OF AREAL DENSITY ON CURVED SPATIAL SURFACE

    OpenAIRE

    Hong Shen

    2011-01-01

    The concepts of curve profile, curve intercept, curve intercept density, curve profile area density, intersection density in containing intersection (or intersection density relied on intersection reference), curve profile intersection density in surface (or curve intercept intersection density relied on intersection of containing curve), and curve profile area density in surface (AS) were defined. AS expressed the amount of curve profile area of Y phase in the unit containing surface area, S...

  14. Neutron irradiation of seeds 2

    Energy Technology Data Exchange (ETDEWEB)

    1968-10-01

    The irradiation of seeds with the fast neutron of research reactors has been hampered by difficulties in accurately measuring dose and in obtaining repeatable and comparable results. Co-ordinated research under an international program organized by the FAO and IAEA has already resulted in significant improvements in methods of exposing seeds in research reactors and in obtaining accurate dosimetry. This has been accomplished by the development of a standard reactor facility for the neutron irradiation of seeds and standard methods for determining fast-neutron dose and the biological response after irradiation. In this program various divisions of the IAEA and the Joint FAO/IAEA Division co-operate with a number of research institutes and reactor centres throughout the world. Results of the preliminary experiments were reported in Technical Reports Series No. 76, ''Neutron Irradiation of Seeds''. This volume contains the proceedings of a meeting of co-operators in the FAO/IAEA Neutron Seed Irradiation Program and other active scientists in this field. The meeting was held in Vienna from 11 to 15 December 1967. Refs, figs and tabs.

  15. Neutron irradiation of seeds 2

    International Nuclear Information System (INIS)

    1968-01-01

    The irradiation of seeds with the fast neutron of research reactors has been hampered by difficulties in accurately measuring dose and in obtaining repeatable and comparable results. Co-ordinated research under an international program organized by the FAO and IAEA has already resulted in significant improvements in methods of exposing seeds in research reactors and in obtaining accurate dosimetry. This has been accomplished by the development of a standard reactor facility for the neutron irradiation of seeds and standard methods for determining fast-neutron dose and the biological response after irradiation. In this program various divisions of the IAEA and the Joint FAO/IAEA Division co-operate with a number of research institutes and reactor centres throughout the world. Results of the preliminary experiments were reported in Technical Reports Series No. 76, ''Neutron Irradiation of Seeds''. This volume contains the proceedings of a meeting of co-operators in the FAO/IAEA Neutron Seed Irradiation Program and other active scientists in this field. The meeting was held in Vienna from 11 to 15 December 1967. Refs, figs and tabs

  16. Polar representation of centrifugal pump homologous curves

    International Nuclear Information System (INIS)

    Veloso, Marcelo Antonio; Mattos, Joao Roberto Loureiro de

    2008-01-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic parameters: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. Any one of these quantities can be expressed as a function of any two others. The curves showing the relationships between these four variables are called the pump characteristic curves, also referred to as four-quadrant curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, the four-quadrant configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the polar form appears as the simplest way to represent the homologous curves. In the polar method, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a

  17. Migration and the Wage-Settings Curve

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke

    Germany on basis of a wage-setting curve. The wage-setting curve relies on the assumption that wages respond to a hange in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously in a general equilibrium framework. Using...

  18. Learning curves in energy planning models

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, L; Kypreos, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    This study describes the endogenous representation of investment cost learning curves into the MARKAL energy planning model. A piece-wise representation of the learning curves is implemented using Mixed Integer Programming. The approach is briefly described and some results are presented. (author) 3 figs., 5 refs.

  19. The Koch curve as a smooth manifold

    International Nuclear Information System (INIS)

    Epstein, Marcelo; Sniatycki, Jedrzej

    2008-01-01

    We show that there exists a homeomorphism between the closed interval [0,1] is contained in R and the Koch curve endowed with the subset topology of R 2 . We use this homeomorphism to endow the Koch curve with the structure of a smooth manifold with boundary

  20. Fermionic fields on ZN-curves

    International Nuclear Information System (INIS)

    Bershadsky, M.; Radul, A.

    1988-01-01

    The line bundles of degree g-1 on Z N -curves corresponding to 1/N nonsingular characteristics are considered. The determinants of Dirac operators defined on these line bundles are evaluated in terms of branch points. The generalization of Thomae's formula for Z N -curves is derived. (orig.)

  1. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  2. A minicourse on moduli of curves

    International Nuclear Information System (INIS)

    Looijenga, E.

    2000-01-01

    These are notes that accompany a short course given at the School on Algebraic Geometry 1999 at the ICTP, Trieste. A major goal is to outline various approaches to moduli spaces of curves. In the last part I discuss the algebraic classes that naturally live on these spaces; these can be thought of as the characteristic classes for bundles of curves. (author)

  3. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-01-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal

  4. Symmetry Properties of Potentiometric Titration Curves.

    Science.gov (United States)

    Macca, Carlo; Bombi, G. Giorgio

    1983-01-01

    Demonstrates how the symmetry properties of titration curves can be efficiently and rigorously treated by means of a simple method, assisted by the use of logarithmic diagrams. Discusses the symmetry properties of several typical titration curves, comparing the graphical approach and an explicit mathematical treatment. (Author/JM)

  5. Deep-learnt classification of light curves

    DEFF Research Database (Denmark)

    Mahabal, Ashish; Gieseke, Fabian; Pai, Akshay Sadananda Uppinakudru

    2017-01-01

    Astronomy light curves are sparse, gappy, and heteroscedastic. As a result standard time series methods regularly used for financial and similar datasets are of little help and astronomers are usually left to their own instruments and techniques to classify light curves. A common approach is to d...

  6. Hyper-and-elliptic-curve cryptography

    NARCIS (Netherlands)

    Bernstein, D.J.; Lange, T.

    2014-01-01

    This paper introduces ‘hyper-and-elliptic-curve cryptography’, in which a single high-security group supports fast genus-2-hyperelliptic-curve formulas for variable-base-point single-scalar multiplication (for example, Diffie–Hellman shared-secret computation) and at the same time supports fast

  7. Curve Matching with Applications in Medical Imaging

    DEFF Research Database (Denmark)

    Bauer, Martin; Bruveris, Martins; Harms, Philipp

    2015-01-01

    In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several...

  8. Regulation of two loblolly pine (Pinus taeda L.) isocitrate lyase genes in megagametophytes of mature and stratified seeds and during postgerminative growth.

    Science.gov (United States)

    Mullen, R T; Gifford, D J

    1997-03-01

    Two full-length cDNAs encoding the glyoxysomal enzyme isocitrate lyase (ICL) were isolated from a lambda ZAP cDNA library prepared from megagametophyte mRNAs extracted from seeds imbibed at 30 degrees C for 8 days. The cDNAs, designated Ptbs ICL 8 and Ptbs ICL 12, have open reading frames of 1740 and 1719 bp, with deduced amino acid sequences of 580 and 573 residues, respectively. The predicted amino acid sequences of Ptbs ICL 8 and Ptbs ICL 12 exhibit a 79% identity with each other, and have a greater than 75% identity with ICLs from various angiosperm species. The C-termini of Ptbs ICL 8 and Ptbs ICL 12 terminate with the tripeptide Ser-Arg-Met and Ala-Arg-Met, respectively, both being conserved variants of the type 1 peroxisomal targeting signal. RNA blot and slot analysis revealed that Ptbs ICL 8 and Ptbs ICL 12 mRNAs were present at low levels in the megagametophyte of the mature and stratified seeds, and that the level of both transcripts increased markedly upon seed germination. Protein blot analysis indicated that the steady-state level of ICL was low in the mature and stratified seed, then increased rapidly upon seed germination, peaking at around 8-10 days after imbibition (DAI). Changes in the level of ICL activity in cell-free extracts was similar to the steady-state protein content with the exception that ICL activity was not detected in megagametophyte extracts of mature or stratified seeds. From 10-12 DAI when the megagametophyte tissue senesced, ICL activity decreased rapidly to near undetectable levels. In contrast, steady-state levels of ICL protein and mRNA remained relatively constant during megagametophyte senescence. In vivo synthesis of ICL protein was measured to shed light on these differences. ICL immunoselected from [(35)S]-methionine labelled proteins indicated that ICL was synthesized at very low levels during megagametophyte senescence. Together, the results show that loblolly pine ICL gene expression is complex. While temporal

  9. [Dynamics of seed rain of Tripterygium hypoglaucum and soil seed bank].

    Science.gov (United States)

    Zhang, Zhi-Wei; Wei, Yong-Sheng; Liu, Xiang; Su, Shu; Qu, Xian-You; Wang, Chang-Hua

    2017-11-01

    Tripterygium hypoglaucum is an endangered species in arid areas of Xiannvshan Chongqing, China. The dynamic characteristics of seed rain and soil seed bank of T. hypoglaucum were studied in this paper.Results showed that T. hypoglaucum years of mature seeds distribution number up to October; the seed rain occurred from the last ten-day of September to in the first ten-day of November and the peak of scattered seed rain concentrated in the October.The numbers of soil seed bank at 2-5 cm soil layer,mainly concentrated in the 1.5-3.5 m range. T. hypoglaucum seeds to the wind as a force for transmission, the transmission ability is strong, but in the process of natural reproduction, full mature seed rate is low, the soil seed bank seeds seed short-lived factors these were unfavorable for the natural reproduction of T. hypoglaucum population. Copyright© by the Chinese Pharmaceutical Association.

  10. Remote sensing used for power curves

    International Nuclear Information System (INIS)

    Wagner, R; Joergensen, H E; Paulsen, U S; Larsen, T J; Antoniou, I; Thesbjerg, L

    2008-01-01

    Power curve measurement for large wind turbines requires taking into account more parameters than only the wind speed at hub height. Based on results from aerodynamic simulations, an equivalent wind speed taking the wind shear into account was defined and found to reduce the power standard deviation in the power curve significantly. Two LiDARs and a SoDAR are used to measure the wind profile in front of a wind turbine. These profiles are used to calculate the equivalent wind speed. The comparison of the power curves obtained with the three instruments to the traditional power curve, obtained using a cup anemometer measurement, confirms the results obtained from the simulations. Using LiDAR profiles reduces the error in power curve measurement, when these are used as relative instrument together with a cup anemometer. Results from the SoDAR do not show such promising results, probably because of noisy measurements resulting in distorted profiles

  11. Factors influencing upon the incidence of seed migration in I-125 seed transperineal prostate implantation

    International Nuclear Information System (INIS)

    Itami, Jun; Onishi, Kayoko; Kanemura, Mikio

    2005-01-01

    Transperineal I-125 seed brachytherapy for prostate cancer is rapidly expanding in Japan. Seed migrations to lung and abdomen are well known complication in the seed brachytherapy. The rate of incidence and the predisposing factors were studied. From April 2004 through January 2005, 36 patients underwent transperineal I-125 seed brachytherapy for prostate cancer. In all patients loose I-125 seeds were inserted with Mick applicator according to modified peripheral loading pattern. One day, 1 week, and 1 month after the procedure, posteroanterior and lateral chest X-rays and abdominal X-ray were performed. Abdominal and chest seed migrations were seen in 11 (30.6%) and 14 (38.9%) patients, respectively. In total, 20 patients (55.6%) showed seed migrations. Forty-two I-125 seeds migrated out of 2,508 implanted seeds. Most of the migrations were seen until 1 month after the procedure. The preplanned number of the extraprostatic seeds had a statistically significant influence upon the incidence of seed migration. Seed migration is not a rare phenomenon in transperineal I-125 seed brachytherapy for prostate cancer. To confirm seed migration, X-ray examinations 1 month after the procedure are suited. At the preplanning, the number of extraprostatic seeds should be limited to minimal to decrease the incidence of seed migration. In future, the introduction of linked I-125 seeds is preferred. (author)

  12. Parametric representation of centrifugal pump homologous curves

    International Nuclear Information System (INIS)

    Veloso, Marcelo A.; Mattos, Joao R.L. de

    2015-01-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)

  13. Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program.

    Science.gov (United States)

    Afouxenidis, D; Polymeris, G S; Tsirliganis, N C; Kitis, G

    2012-05-01

    This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the GLOw Curve ANalysis INtercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters.

  14. Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program

    International Nuclear Information System (INIS)

    Afouxenidis, D.; Polymeris, G. S.; Tsirliganis, N. C.; Kitis, G.

    2012-01-01

    This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the Glow Curve Analysis Intercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters. (authors)

  15. Ash (Fraxinus excelsior) seed quality in relation to seed ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... bottles were seal-locked and kept in the accelerated ageing cham- ber at three ... Hundred (100) seeds of each treatment were performed in plastic ..... by heat stress: the activation state of Rubisco as a limiting factor in.

  16. Effects of seed fermentation method on seed germination and vigor ...

    African Journals Online (AJOL)

    BERTIN

    2013-11-27

    Nov 27, 2013 ... high, suggesting that wet soil is necessary for an on farm reliable evaluation of seed fermentation method in the .... with tap water, and sundried in ambient air until attaining 6 to 7% moisture. ..... arabica in Brazil. Int. J. Food ...

  17. Nutrient composition of Dacryodes edulis seed and seed coat mixture

    Directory of Open Access Journals (Sweden)

    C.U. OGUNKA-NNOKA

    2017-07-01

    Full Text Available This study investigated the nutrient composition of D. edulis seed and seed coat mixture. Qualitative and quantitative phytochemicals, proximate, and vitamin compositions were evaluated using standard methods. Saponins were very high, alkaloids, flavonoids, and tannins were high, while terpenoids were low, and glycosides, aldehydes, and steroids were absent. The quantitative phytochemical determination followed the order; saponin > kaempferol > rutin > catechin > tannin > sapogenin > lunamarine > phenol > ribalinidine > anthocyanin > oxalate > phytate. For the proximate composition, carbohydrates had the highest concentration, followed by lipids and fibre, while, protein concentration was the lowest. Vitamin E (5.42 mg/100g, vitamin C (3.24 mg/100g, and vitamin A (2.84 mg/100g were the highest occurring constituent vitamins while vitamin B12 (0.035 mg/100g and vitamin B2 (0.075 mg/100g were the least occurring vitamins. This study has shown the rich phytochemical composition of D. edulis seed and seed coat mixture while showing deficiencies in proteins, distinct vitamins, and ash contents.

  18. Chlorophyll in tomato seeds: marker for seed performance?

    NARCIS (Netherlands)

    Suhartanto, M.R.

    2002-01-01

    Using Xe-PAM, laser induced fluorometry and high performance liquid chromatography we found that chlorophyll was present in young tomato (cv. Moneymaker) seeds and was degraded during maturation. Fluorescence microscopy and imaging showed that the majority of chlorophyll is located in the

  19. The role of seed priming in improving seed germination and ...

    African Journals Online (AJOL)

    win7

    2013-11-13

    Nov 13, 2013 ... As a result, fresh and dry weights of shoot and root were improved. Seed priming alleviated the inhibitory effect of salt stress on germination and seedling growth of maize under salt stress. ... Salinization is more spreading in irrigated lands because of inappropriate management of irrigation and drainage.

  20. Mannheim Partner D-Curves in the Euclidean 3-space

    Directory of Open Access Journals (Sweden)

    Mustafa Kazaz

    2015-02-01

    Full Text Available In this paper, we consider the idea of Mannheim partner curves for curves lying on surfaces. By considering the Darboux frames of surface curves, we define Mannheim partner D-curves and give the characterizations for these curves. We also find the relations between geodesic curvatures, normal curvatures and geodesic torsions of these associated curves. Furthermore, we show that definition and characterizations of Mannheim partner D-curves include those of Mannheim partner curves in some special cases.