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Sample records for growing shoot tips

  1. Shoot regeneration and embryogenesis in lily shoot tips cryopreserved by droplet vitrification

    Science.gov (United States)

    Shoot regeneration and embryogenesis were, for the first time, achieved directly in shoot tips of Lilium Oriental hybrid ‘Siberia’ following cryopreservation by droplet-vitrification. Shoot tips (2 mm in length) including 2-3 leaf primordia were excised from 4-week-old adventitious shoots directly r...

  2. Propagation of pineapple by shoot tip culture

    International Nuclear Information System (INIS)

    Almobasher, H. A. A.; Osman, M. G.; Said, A. E.

    2009-01-01

    This study was conducted with the objective of modifying the composition of MS medium for the clonal propagation of pineapple using shoot tips of Smooth Cayenne cultivar. Modification were made on various medium components. Results showed that both MS salts at the full or half strength were optimal, and there was on significant difference between them. Sucrose concentrations of 3% and 6% were better than other concentrations tested for growth and development of plant lets. The cultures responded positively to the increase of adenine sulfate and 80 mg/1 was the optimal. As for the additions of NAA and BA , alone or in combinations, the best results were recorded with the combination of NAA at 0.01 mg/1, and BA at 3.0 mg/1 where the largest number of shoots was obtained. Better explants performance was achieved on liquid medium with cotton support compared to solid medium. (Author)

  3. Efficient regeneration of plants from shoot tip explants of ...

    African Journals Online (AJOL)

    Dendrobium densiflorum Lindl. is one of the horticulturally important orchids of Nepal due to its beautiful yellowish flower and medicinal properties. The present study was carried out for plant regeneration from shoot tip explants of D. densiflorum by tissue culture technique. The shoot tip explants of this species, obtained ...

  4. Gene expression in arabidopsis shoot tips after liquid nitrogen exposure

    Science.gov (United States)

    Arabidopsis thaliana shoot tips can be successfully cryopreserved using either Plant Vitrification Solution 2 (PVS2) or Plant Vitrification Solution 3 (PVS3) as the cryoprotectant. We used this model system to identify suites of genes that were either upregulated or downregulated as shoot tips recov...

  5. Cryopreservation of in vitro -grown shoot tips of apricot ( Prunus ...

    African Journals Online (AJOL)

    In vitro grown apricot (Prunus armeniaca L.) cv. El-Hamawey shoot tips were successfully cryopreserved using an encapsulation-dehydration procedure. Shoot tips were encapsulated in calcium-alginate beads before preculture on woody plant (WP) medium supplemented with different sucrose concentrations; 0.1, 0.3, 0.5, ...

  6. Production of polyploids from cultured shoot tips of Eucalyptus ...

    African Journals Online (AJOL)

    Polyploids from cultured shoot tips of Eucalyptus globulus were produced by treatment with colchicine. Results showed that the combination of 0.5% colchicine and treating multiple shoot clumps for 4 days was the most appropriate conditions for E. globulus polyploidy induction and the effect of the use of multiple shoot ...

  7. Modeling shoot-tip temperature in the greenhouse environment

    International Nuclear Information System (INIS)

    Faust, J.E.; Heins, R.D.

    1998-01-01

    An energy-balance model is described that predicts vinca (Catharanthus roseus L.) shoot-tip temperature using four environmental measurements: solar radiation and dry bulb, wet bulb, and glazing material temperature. The time and magnitude of the differences between shoot-tip and air temperature were determined in greenhouses maintained at air temperatures of 15, 20, 25, 30, or 35 °C. At night, shoot-tip temperature was always below air temperature. Shoot-tip temperature decreased from 0.5 to 5 °C below air temperature as greenhouse glass temperature decreased from 2 to 15 °C below air temperature. During the photoperiod under low vapor-pressure deficit (VPD) and low air temperature, shoot-tip temperature increased ≈4 °C as solar radiation increased from 0 to 600 W·m -2 . Under high VPD and high air temperature, shoot-tip temperature initially decreased 1 to 2 °C at sunrise, then increased later in the morning as solar radiation increased. The model predicted shoot-tip temperatures within ±1 °C of 81% of the observed 1-hour average shoot-tip temperatures. The model was used to simulate shoot-tip temperatures under different VPD, solar radiation, and air temperatures. Since the rate of leaf and flower development are influenced by the temperature of the meristematic tissues, a model of shoot-tip temperature will be a valuable tool to predict plant development in greenhouses and to control the greenhouse environment based on a plant temperature setpoint. (author)

  8. High frequency plant regeneration from shoot tip explants of ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... 16/8-h (light/dark) photoperiod provided by cool white fluorescent light. Multiple .... formation from shoot tip explant of C. colocynthis on MS-medium. S. No. .... micropropagation of Musa sapientum L. (Cavendish Dwarf). Afr. J.

  9. High Frequency Multiple Shoot Induction of Curculigo orchioides Gaertn.: Shoot Tip V/S Rhizome Disc

    Directory of Open Access Journals (Sweden)

    K. S. Nagesh

    2008-09-01

    Full Text Available Curculigo orchioides Gaertn. is an endangered medicinal plant with anticancer properties. The rhizome and tuberous roots of the plant have been used extensively in India in indigenous medicine. Due to its multiple uses, the demand for Curculigo orchioides is constantly on the rise; however, the supply is rather erratic and inadequate. Destructive harvesting, combined with habitat destruction in the form of deforestation has aggravated the problem. The plant is now considered ‘endangered’ in its natural habitat. Therefore, the need for conservation of this plant is crucial. Here, we describe a successful protocol for multiple shoot induction of C. orchioides using shoot tip and rhizome disc. We find that proximal rhizome discs are optimal for high frequency shoot bud formation than shoot tip and distal rhizome disc. We observed a synergistic effect between 6-benzylaminopurine (BAP and kinetin (KN (each at 1 mg/L on the regeneration of shoot buds from proximal rhizome disc than shoot tip explant. Optimum root induction was achieved on half-strength MS liquid medium supplemented with 1 mg/L of indole-3-butyric acid (IBA. The in vitro raised plantlets were acclimatized in green house and successfully transplanted to natural condition with 90% survival.

  10. Efficient regeneration of sorghum, Sorghum bicolor (L.) Moench, from shoot-tip explant.

    Science.gov (United States)

    Syamala, D; Devi, Prathibha

    2003-12-01

    Novel protocols for production of multiple shoot-tip clumps and somatic embryos of Sorghum bicolor (L.) Moench were developed with long-term goal of crop improvement through genetic transformation. Multiple shoot-tip clumps were developed in vitro from shoot-tip explant of one-week old seedling, cultured on MS medium containing only BA (0.5, 1 or 2 mg/l) or both BA (1 or 2 mg/l) and 2,4-D (0.5 mg/l) with bi-weekly subculture. Somatic embryos were directly produced on the enlarged dome shaped growing structures that developed from the shoot-tips of one-week old seedling explants (without any callus formation) when cultured on MS medium supplemented with both 2,4-D (0.5 mg/l) and BA (0.5 mg/l). However, the supplementation of MS medium with only 2,4-D (0.5 mg/l) induced compact callus without any plantlet regeneration. Each multiple shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing indole-3-butyric acid (IBA 1 mg/l). The plants were successfully transplanted to glasshouse and grown to maturity with a survival rate of 98%. Morphogenetic response of the explants was found to be genotypically independent.

  11. In vitro shoot multiplication of Ziziphus spina-christi by shoot tip culture

    African Journals Online (AJOL)

    USER

    2010-02-08

    Feb 8, 2010 ... Key words: Clonal propagation, cidir, shoot tip culture, Ziziphus spina-christi (L.) Desf. INTRODUCTION. Ziziphus spina-christi (L.) Desf., locally known as cidir, is a multipurpose tree species belonging to the botanical family Rhamnaceae. It is an important cultivated tree and one of the few truly native tree ...

  12. Effects of irradiation on physicochemical and sensory qualities of fermented shoot tip of sweet potato

    International Nuclear Information System (INIS)

    Cui Li; Liu Chunquan; Li Dajing; Song Jiangfeng; Jiang Ning; Liu Chunju; Wu Haihong; Zhu Danyu

    2011-01-01

    The effect of irradiation on sensory quality, physicochemical and functional prosperities of fermented shoot tips of sweet potatoes were studied. The results showed that total content of free amino acids in fermented shoot tips of sweet potato were not influenced at 4 kGy irradiation, but increased at 6 kGy. Total content of organic acids in shoot tips were not influenced by 2 ∼ 6 kGy of irradiation. The total viable cells of the tips was reduced from 7.35 to 4.67 log CFU/g at 2 kGy irradiation, and no growth of total viable cells was observed at 4 and 6 kGy irradiated fermented shoot tips. It is recommended that 4 kGy was the endurance irradiation dose for fermented shoot tips of sweet potato to ensure the maximum retention of taste quality and health-relevant functionality. (authors)

  13. In-vitro morphogenesis of corn (Zea mays L.) : I. Differentiation of multiple shoot clumps and somatic embryos from shoot tips.

    Science.gov (United States)

    Zhong, H; Srinivasan, C; Sticklen, M B

    1992-07-01

    In-vitro methods have been developed to regenerate clumps of multiple shoots and somatic embryos at high frequency from shoot tips of aseptically-grown seedlings as well as from shoot apices of precociously-germinated immature zygotic embryos of corn (Zea mays L.). About 500 shoots were produced from a shoot tip after eight weeks of culture (primary culture and one subculture of four weeks) in darkness on Murashige and Skoog basal medium (MS) supplemented with 500 mg/L casein hydrolysate (CH) and 9 μM N(6)-benzyladenine (BA). In this medium, shoots formed in shoot tips as tightly packed "multiple shoot clumps" (MSC), which were composed of some axillary shoots and many adventitious shoots. When the shoot tips were cultured on MS medium containing 500 mg/L CH, 9 μM BA and 2.25 μM 2,4-dichlorophenoxyacetic acid (2,4-D), most of the shoots in the clumps were adventitious in origin. Similar shoot tips cultured on MS medium containing 500 mg/L CH, 4.5 μM BA and 2.25 μM 2,4-D regenerated many somatic embryos within eight weeks of culture. Somatic embryos were produced either directly from the shoot apical meristems or from calli derived from the shoots apices. Both the MSC and the embryos produced normal shoots on MS medium containing 2.25 μM BA and 1.8 μM indole-3-butyric acid (IBA). These shoots were rooted on MS medium containing 3.6 μM IBA, and fertile corn plants were grown in the greenhouse. The sweet-corn genotype, Honey N Pearl, was used for the experiments described above, but shoot-tip cultures from all of 19 other corn genotypes tested also formed MSC on MS medium containing 500 mg/L CH and 9 μM BA.

  14. Radiosensitivity of in vitro Cultured Banana Shoot-Tips

    International Nuclear Information System (INIS)

    Elagamawy, M.R.

    2002-01-01

    Longitudinally dissected shoot apices of Grand Nain, Williams and Maghrabi banana cultivars were exposed to gamma irradiation with Cobalt 60 source at the doses of 0, 20, 40 and 60 Gy and immediately placed into proliferation medium. A number of micropropagation cycles after irradiation were necessary up to M1 V2 to M1 V4 stage to let mutated sectors developing into non-chimeric shoots. Radiosensitivity was evaluated by the rate of shoot proliferation and by the shoot fresh weight increase. Increasing gamma doses caused reduction in survival rates and average number of shoots. Grand Nain exhibited the highest multiplication- rate (3.1). The lower dose (20 Gy) enhanced shoot multiplication ratio specially in Williams and Maghrabi, which however decreased with increased doses. The doses of 20-40 Gy yielded Ld50, with sensible degree of shoot multiplication, which occurred hardly ever beyond 40 Gy. The dose of 60 Gy resulted 80% lethal shoot growth. Linear decrease in fresh weight was observed in post-irradiation recovery, notably in the Maghrabi. In contradictory vulnerable damage was observed in Williams which showed the highest fresh weight value. Shoot proliferation appeared generally on the surface of the corm. Root formation was observed without additional hormone. The roots were dark colored and was decreased with the increased of dosage

  15. Microclonal Multiplication of wild Cherry (Prunus avium L.) from Shoot Tips and Root Sucker Buds

    OpenAIRE

    Pevalek-Kozlina, Branka; Michler, Charles H.; Jelaska, Sibila

    1994-01-01

    The effects of different combinations and concentrations of the growth regulators: 6-benzylaminopurine (BA), 6-furfurylaminopurine (KIN), N6- (2-isopentenyl) adenine (2iP), indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) and a-naphthaleneacetic acid (NAA) on axillary shoot multiplication rates for wild cherry (Prunus avium L.) shoot explants were determined. Apical shoot tips and axillary buds from juvenile trees (5-year old) and from root suckers of mature trees (55-year old) were us...

  16. The Sandy Hook Elementary School shooting as tipping point

    Science.gov (United States)

    Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M

    2013-01-01

    Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States. PMID:28228989

  17. Micropropagation of Plantago asiatica L. through culture of shoot-tips

    Directory of Open Access Journals (Sweden)

    Joanna Makowczyńska

    2011-01-01

    Full Text Available Shoot-tip multiplication of the medicinal species - Plantago asiatica was carried on MS medium with IAA and BAP or kinetin. Best results in micropropagation were achieved by adding 0.1 mg/dm3 IAA and 1 mg/dm3 BAP. After 6 weeks shoots were transferred to MS medium for rooting. The resulting plantlets were transferred after 8 weeks into pots and after a period of adaptation into the ground (field culture. The species Plantago asiatica was propagated in vitro by shoot-tip multiplication for the first time.

  18. Improved recovery of cryotherapy-treated shoot tips following thermotherapy of in vitro-grown stock shoots of raspberry (Rubus idaeus L.).

    Science.gov (United States)

    Wang, Qiaochun; Valkonen, Jari P T

    2009-01-01

    Raspberry bushy dwarf virus (RBDV) can be efficiently eradicated from raspberry plants (Rubus idaeus) by a procedure combining thermotherapy and cryotherapy. However, the bottleneck of this procedure is that, following thermotherapy, cryopreserved shoot tips become chlorotic during regrowth and eventually die after several subcultures. In addition, survival of heat-treated stock shoots and recovery of cryopreserved shoot tips following thermotherapy are low. The present study focused towards improving regrowth of cryopreserved raspberry shoot tips following thermotherapy. Results showed that preconditioning stock shoots with salicylic acid (SA; 0.01-0.1 mM) markedly increased survival of stock shoots after 4 weeks of thermotherapy. Regrowth of cryopreserved shoot tips following thermotherapy was also significantly enhanced when SA (0.05-0.1 mM) was used for preconditioning stock shoots. Addition of either Fe-ethylenediaminetetracetic acid (Fe-EDTA, 50 mg per L) or Fe-ethylenediaminedi(o)hydroxyphenylacetic acid (Fe-EDDHA, 50 mg per L) to post-culture medium strongly promoted regrowth and totally prevented chlorosis of shoots regenerated from cryopreserved shoot tips following thermotherapy. Using the parameters optimized in the present study, about 80 percent survival of heat-treated stock shoots and about 33 percent regrowth of cryopreserved shoot tips following thermotherapy were obtained. Morphology of plants regenerated from cryopreserved shoot tips following thermotherapy was identical to that of control plants, based on observations of leaf shape and size, internode length and plant height. Optimization of the thermotherapy procedure followed by cryotherapy will facilitate the wider application of this technique to eliminate viruses which can invade meristems.

  19. Alginate-encapsulation of shoot tips of jojoba [Simmondsia chinensis (Link) Schneider] for germplasm exchange and distribution.

    Science.gov (United States)

    Kumar, Sunil; Rai, Manoj K; Singh, Narender; Mangal, Manisha

    2010-12-01

    Shoot tips excised from in vitro proliferated shoots derived from nodal explants of jojoba [Simmondsia chinensis (Link) Schneider] were encapsulated in calcium alginate beads for germplasm exchange and distribution. A gelling matrix of 3 % sodium alginate and 100 mM calcium chloride was found most suitable for formation of ideal calcium alginate beads. Best response for shoot sprouting from encapsulated shoot tips was recorded on 0.8 % agar-solidified full-strength MS medium. Rooting was induced upon transfer of sprouted shoots to 0.8 % agar-solidified MS medium containing 1 mg l(-1) IBA. About 70 % of encapsulated shoot tips were rooted and converted into plantlets. Plants regenerated from encapsulated shoot tips were acclimatized successfully. The present encapsulation approach could also be applied as an alternative method of propagation of desirable elite genotype of jojoba.

  20. Encapsulation of nodal cuttings and shoot tips for storage and exchange of cassava germplasm.

    Science.gov (United States)

    Danso, K E; Ford-Lloyd, B V

    2003-04-01

    We report the encapsulation of in vitro-derived nodal cuttings or shoot tips of cassava in 3% calcium alginate for storage and germplasm exchange purposes. Shoot regrowth was not significantly affected by the concentration of sucrose in the alginate matrix while root formation was. In contrast, increasing the sucrose concentration in the calcium chloride polymerisation medium significantly reduced regrowth from encapsulated nodal cuttings of accession TME 60444. Supplementing the alginate matrix with increased concentrations of 6-benzylaminopurine and alpha-naphthaleneacetic acid enhanced complete plant regrowth within 2 weeks. Furthermore, plant regrowth by encapsulated nodal cuttings and shoot tips was significantly affected by the duration of the storage period as shoot recovery decreased from almost 100% to 73.3% for encapsulated nodal cuttings and 94.4% to 60% for shoot tips after 28 days of storage. The high frequency of plant regrowth from alginate-coated micropropagules coupled with high viability percentage after 28 days of storage is highly encouraging for the exchange of cassava genetic resources. Such encapsulated micropropagules could be used as an alternative to synthetic seeds derived from somatic embryos.

  1. Recovery patterns, histological observations and genetic integrity in Malus shoot tips cryopreserved using droplet vitrification and encapsulation-dehydration procedures

    Science.gov (United States)

    A droplet-vitrification procedure is described for cryopreservation of Malus shoot tips. Survival patterns, recovery types, histological observations, and genetic integrity were compared for Malus shoot tips cryopreserved using this droplet-vitrification procedure and an encapsulation-dehydration pr...

  2. Effects of fungicides and bactericides on orchid seed germination and shoot tip cultures in vitro

    OpenAIRE

    Brown, DM; Groom, CL; Cvitanik, M; Brown, M; Cooper, JL; Arditti, J

    1981-01-01

    Amphotericin B, benomyl, gentamycin, nystatin, quintozene penicillin G, sodium omadine, and vancomycin singly and in several combinations have no deleterious effects on the germination of orchid seeds, but inhibit the growth in vitro of shoot tip explants. © 1981 Martinus Nijhoff/Dr W. Junk Publishers.

  3. Gene expression in response to cryoprotectant and liquid nitrogen exposure in Arabidopsis shoot tips

    Science.gov (United States)

    Arabidopsis thaliana is an ideal model system to study plant cryopreservation at the molecular level. We have developed reliable cryopreservation methods for Arabidopsis shoot tips using Plant Vitrification Solution 2 and Plant Vitrification Solution 3 (PVS3) cryoprotectants. We have made use of th...

  4. Control of lethal browning by using ascorbic acid on shoot tip ...

    African Journals Online (AJOL)

    The use of ascorbic acid during explants preparation and the effect of different concentrations of ascorbic acid in controlling lethal browning and survival of the explants in local banana cv. Mzuzu banana were investigated. The explants were taken from young suckers. The shoot tips were cultured on Murashige and Skoog's ...

  5. Effect of biweekly shoot tip harvests on the growth and yield of Georgia Jet sweet potato grown hydroponically

    Science.gov (United States)

    Ogbuehi, Cyriacus R.; Loretan, Phil A.; Bonsi, C. K.; Hill, Walter A.; Morris, Carlton E.; Biswas, P. K.; Mortley, Desmond G.

    1989-01-01

    Sweet potato shoot tips have been shown to be a nutritious green vegetable. A study was conducted to determine the effect of biweekly shoot tip harvests on the growth and yield of Georgia Jet sweet potato grown in the greenhouse using the nutrient film technique (NFT). The nutrient solution consisted of a modified half Hoagland solution. Biweekly shoot tip harvests, beginning 42 days after planting, provided substantial amounts of vegetable greens and did not affect the fresh and dry foliage weights or the storage root number and fresh and dry storage root weights at final harvest. The rates of anion and cation uptake were not affected by tip harvests.

  6. Cryopreservation of in vitro grown shoot tips and apical meristems of the forage legume Arachis pintoi.

    Science.gov (United States)

    Rey, Hebe Y; Faloci, Mirta; Medina, Ricardo; Dolce, Natalia; Mroginski, Luis; Engelmann, Florent

    2009-01-01

    A cryopreservation protocol using the encapsulation-dehydration procedure was established for shoot tips (2-3 mm in length) and meristems (0.3-0.5 mm) sampled from in vitro plantlets of diploid and triploid cytotypes of Arachis pintoi. The optimal protocol was the following: after dissection, explants were precultured for 24 h on establishment medium (EM), encapsulated in calcium alginate beads and pretreated in liquid EM medium with daily increasing sucrose concentration (0.5, 0.75, 1.0 M) and desiccated to 22-23 percent moisture content (fresh weight basis). Explants were frozen using slow cooling (1 C per min from 25C to -30C followed by direct immersion in liquid nitrogen), thawed rapidly and post-cultured in liquid EM medium enriched with daily decreasing sucrose concentrations (0.75, 0.50, 0.1 M). Explants were then transferred to solid EM medium in order to achieve shoot regeneration, then on Murashige and Skoog medium supplemented with 0.05 microM naphthalene acetic acid to induce rooting of shoots. With this procedure, 53 percent and 56 percent of cryopreserved shoot tips of the diploid and triploid cytotypes, respectively, survived and formed plants. However, only 16 percent of cryopreserved meristems of both cytotypes regenerated plants. Using ten isozyme systems and seven RAPD profiles, no modification induced by cryopreservation could be detected in plantlets regenerated from cryopreserved material.

  7. Numerical investigation of J-characterization of growing crack tips

    International Nuclear Information System (INIS)

    Nilsson, F.

    1992-01-01

    Two different geometries, a centrally cracked panel and a three-point bend bar, are modelled with aid of the finite element program ABAQUS. Elastic-plastic behaviour with a realistic linear hardening modulus is assumed. By simulation of the growth with the aid of nodal relaxation, the J-value for a remote path around the growing tip is obtained for some different local-crack growth histories. The J F -value is compared to the J D -value that results if the crack tip is assumed to be stationary at the current length. It is found that the J C - and J F -values agree well for crack growth histories satisfying the criteria for J-characterization. However, after examination of the crack surface displacements it was found that the results for the bend geometry and the tension geometry, respectively, did not coincide for corresponding J-values, except at low load levels. This raises doubt about the abilities of J to characterize the state at a growing tip. (orig.)

  8. Shoot regeneration of limau purut (citrus hystrix) using shoot tip: assessment of calcium gluconate and silver nitrate in overcoming premature leaf senescence

    International Nuclear Information System (INIS)

    Eng, W.H.; Aziz, M.A.; Sinniah, U.R.

    2014-01-01

    This study was carried out to establish an optimum In vitro shoot multiplication system using shoot tip explants derived from 7 week-old seedlings of Citrus hystrix. In the first experiment, shoot tips were cultured on Murashige and Skoog (MS) medium supplemented with 0-13.33 mu M 6-benzylaminopurine (BAP) for 8 weeks. Shoot tips cultured on 2.22 mu M BAP produced the highest mean number of shoots (3.42 shoots) but the shoots had low number of leaves (1.14 leaves) due to the occurrence of premature leaf senescence and callus formation. Meanwhile, the medium devoid of BAP produced the lowest mean number of shoots (1.50 shoots) but highest mean number of leaves (5.41 leaves) indicating that BAP was likely responsible for the premature leaf senescence. In order to overcome the occurrence of premature leaf senescence on medium with BAP, a second experiment was carried out whereby shoot tips were cultured on medium containing 2.22 micro M BAP fortified with 2.00, 4.00 and 6.00 mM calcium gluconate (Ca-glu) and a control treatment with 2.22 mu M BAP. The shoot and leaf numbers were increased with the addition of 4.00 and 6.00 mM Ca-glu. The presence of Ca-glu reduced premature leaf senescence and callus formation to some extent. In the third experiment, the addition of silver nitrate (AgNO/sub 3/) at 10-80 micro M in media with 2.22 micro M BAP and 2.22 micro M BAP + 4 mM Ca-glu could totally overcome premature leaf senescence and callus formation. Media supplemented with 2.22 mirco M BAP + 4 mM Ca-glu + 20 micro M AgNOsub 3/ significantly induced among the highest mean number of shoots and highest mean number of leaves per shoot. (author)

  9. Crack Tip Parameters for Growing Cracks in Linear Viscoelastic Materials

    DEFF Research Database (Denmark)

    Brincker, Rune

    In this paper the problem of describing the asymptotic fields around a slowly growing crack in a linearly viscoelastic material is considered. It is shown that for plane mixed mode problems the asymptotic fields must be described by 6 parameters: 2 stress intensity factors and 4 deformation...... intensity factors. In the special case of a constant Poisson ratio only 2 deformation intensity factors are needed. Closed form solutions are given both for a slowly growing crack and for a crack that is suddenly arrested at a point at the crack extension path. Two examples are studied; a stress boundary...... value problem, and a displacement boundary value problem. The results show that the stress intensity factors and the displacement intensity factors do not depend explicitly upon the velocity of the crack tip....

  10. Micropropagation of Dianthus deltoides L. through shoot tip and nodal cuttings culture

    Directory of Open Access Journals (Sweden)

    Marković Marija

    2013-01-01

    Full Text Available Micropropagation (shoot tip and nodal cuttings culture was used for the rapid propagation of the non-invasive, decorative, native plants of maiden pink (Dianthus deltoides L. in order to preserve their genetic diversity. In vitro culture was successfully established on Murashige and Skoog medium (MS using seeds as the initial material. In the shoot multiplication phase, the explants were cultured on MS medium supplemented with different concentrations of 6-benzylaminopurine (BAP and naphthaleneacetic acid (NAA. The highest multiplication rate was achieved on a medium containing 0.1 mgL-1 of BAP and 0.1 mgL-1 of NAA. The rooting was successful on a hormone-free medium (100%, and the highest percentage of microplant acclimatization (97% was recorded in a 4: 1 mixture of peat and sand. [Projekat Ministarstva nauke Republike Srbije, br. TR 31041: Establishment of wood plantations intended for a forestation of Serbia

  11. Cultivation Versus Molecular Analysis of Banana (Musa sp.) Shoot-Tip Tissue Reveals Enormous Diversity of Normally Uncultivable Endophytic Bacteria.

    Science.gov (United States)

    Thomas, Pious; Sekhar, Aparna Chandra

    2017-05-01

    The interior of plants constitutes a unique environment for microorganisms with various organisms inhabiting as endophytes. Unlike subterranean plant parts, aboveground parts are relatively less explored for endophytic microbial diversity. We employed a combination of cultivation and molecular approaches to study the endophytic bacterial diversity in banana shoot-tips. Cultivable bacteria from 20 sucker shoot-tips of cv. Grand Naine included 37 strains under 16 genera and three phyla (Proteobacteria, Actinobacteria, Firmicutes). 16S rRNA gene-ribotyping approach on 799f and 1492r PCR-amplicons to avoid plant organelle sequences was ineffective showing limited bacterial diversity. 16S rRNA metagene profiling targeting the V3-V4 hypervariable region after filtering out the chloroplast (74.2 %), mitochondrial (22.9 %), and unknown sequences (1.1 %) revealed enormous bacterial diversity. Proteobacteria formed the predominant phylum (64 %) succeeded by Firmicutes (12.1 %), Actinobacteria (9.5 %), Bacteroidetes (6.4 %), Planctomycetes, Cyanobacteria, and minor shares (banana shoot-tips (20 phyla, 46 classes) with about 2.6 % of the deciphered 269 genera and 1.5 % of the 656 observed species from the same source of shoot-tips attained through cultivation. The predominant genera included several agriculturally important bacteria. The study reveals an immense ecosystem of endophytic bacteria in banana shoot tissues endorsing the earlier documentation of intracellular "Cytobacts" and "Peribacts" with possible roles in plant holobiome and hologenome.

  12. Influence of calcium content of tissue on hyperhydricity and shoot-tip necrosis of in vitro regenerated shoots of Lavandula angustifolia Mill.

    Directory of Open Access Journals (Sweden)

    Marília Pereira Machado

    2014-10-01

    Full Text Available In the present study, the effects of two CaCl2.2H2O levels (440 and 1320 mg L-1 and two subcultures were evaluated on in vitro shoots of Lavandula angustifolia cv. Provence Blue. Ca2+ content of the apical, middle and basal portion of shoots was determined. Increasing CaCl2.2H2O level in the culture medium increased tissue Ca2+ content and decreased hyperhydricity. Shoot-tip necrosis also decreased with 1320 mg L-1 CaCl2.2H2O, but it did not occur in the second subculture. The middle and basal portion had higher Ca2+ content than apical portion. In non-hyperhydric tissues, there were smaller and more juxtaposed cells. Scanning electron microscopy of the leaves demonstrated that trichomes from in vitro leaf surface occurred in smaller quantities.

  13. In vitro propagation of peanut (Arachis hypogaea L.) by shoot tip culture.

    Science.gov (United States)

    Ozudogru, Elif Aylin; Kaya, Ergun; Lambardi, Maurizio

    2013-01-01

    Peanut (Arachis hypogaea L.), also known as groundnut, is the most important species of Arachis genus, originating from Brazil and Peru. Peanut seeds contain high seed oil, proteins, amino acids, and vitamin E, and are consumed worldwide as edible nut, peanut butter, or candy, and peanut oil extracted from the seeds. The meal remaining after oil extraction is also used for animal feed. However, its narrow germplasm base, together with susceptibility to diseases, pathogens, and weeds, decreases yield and seed quality and causes great economic losses annually. Hence, the optimization of efficient in vitro propagation procedures would be highly effective for peanut propagation, as it would raise yield and improve seed quality and flavor. Earlier reports on traditional micropropagation methods, based on axillary bud proliferation which guarantees the multiplication of true-to-type plants, are still limited. This chapter describes a micropropagation protocol to improve multiple shoot formation from shoot-tip explants by using AgNO(3) in combination with plant growth regulators.

  14. Ultrastructure and histology of organogenesis induced from shoot tips of maize (Zea mays, Poaceae

    Directory of Open Access Journals (Sweden)

    Walter Marín-Méndez

    2009-11-01

    Full Text Available Shoot tips of maize (Zea mays L. were cultured on Murashige and Skoog medium supplemented with 2 mg/l BA +1 mg/l 2,4-D +40 mg/l, to investigate phases of ontogenetic development. The study used light microscopy as well as scanning and transmission electronic microscopy techniques. Shoot tips of maize are composed of small cells with a dense cytoplasm and a prominent nucleus. The process of organogenesis began with swelling of the shoot tip, as the first evidence of organogenic calli formation observed three weeks after culture get started. There were two morphologically different types of cells within the organogenic calli. The layer consisted of large cells with small nucleus, free-organelle cytosol, irregular plasmatic membrane, trichome-like structures, and thick cell walls. In the inner cell layer, small and isodiametric cells with a prominent nucleus, small vacuoles, endoplasmatic reticulum, Golgi, mitochondrias and chloroplasts were observed. The presence of trichomes in the more active morphogenic zones could indicate an organogenic potential. Rev. Biol. Trop. 57 (Suppl. 1: 129-139. Epub 2009 November 30.Los ápices de vástagos de maíz (Zea mays L. fueron cultivados con el medio Murashige y Skoog, utilizando como suplemento 2 mg/l BA +1 mg/l 2,4-D +40 mg/l, con el fin de investigar el proceso organogénico durante las diferentes fases del desarrollo ontogenético. El estudio utilizó tanto microscopía de luz, como técnicas de microscopía electrónica. Los análisis histológicos revelaron que los vástagos de maíz están compuestos de pequeñas células con citoplasma denso y núcleo prominente. El proceso de organogénesis inicia con el engrosamiento del ápice del vástago, como primera evidencia de la formación organogénica del calli observada tres semanas después del inicio del cultivo. El estudio ultraestructural muestra dos tipos de células morfológicamente diferentes en el calli organogénico. La capa externa consiste de

  15. Auxin-cytokinin synergism in vitro for producing genetically stable plants of Ruta graveolens using shoot tip meristems

    Directory of Open Access Journals (Sweden)

    Mohammad Faisal

    2018-02-01

    Full Text Available An efficient micropropagation protocol was developed for Ruta graveolens Linn. using shoot tip meristems derived from a 4-month-old field grown plant. In vitro shoot regeneration and proliferation was accomplished on Murashige and Skoogs (MS semi-solid medium in addition to different doses of cytokinins viz.6- benzyl adenine (BA, Kinetin (Kn or 2-isopetynyl adenine (2iP, singly or in combination with auxins viz. indole-3-acetic acid (IAA, indole-3-butyric acid (IBA or α-naphthalene acetic acid (NAA. Highest regeneration frequency (27.6% was obtained on (MS medium composed of BA (10 µM with maximum number (9.4 of shoots and 4.3 cm shoot length after 4 weeks of incubation. Among various combinations tried best regeneration frequency (71% of multiple shoot formation with highest number (12.6 of shoots per shoot tip explants were achieved in MS medium augmented with a combination BA (10.0 µM and NAA (2.5 µM after 4 weeks of incubation. The optimum frequency (97% of rhizogenesis was achieved on half-strength MS medium having 0.5 µM IBA after 4 weeks of incubation. Tissue culture raised plantlets with 5–7 fully opened leaves with healthy root system were successfully acclimatized off in Soilrite™ with 80% survival rate followed by transportation to normal soil under natural light. Genetic stability among in vitro raised progeny was evaluated by ISSR and RAPD markers. The entire banding pattern revealed from in vitro regenerated plants was monomorphic to the donor. The present protocol provides an alternative option for commercial propagation and fruitful setting up of genetically uniform progeny for sustainable utilization and germplasm preservation.

  16. Changes in transcript expression patterns as a result of cryoprotectant treatment and liquid nitrogen exposure in Arabidopsis shoot tips.

    Science.gov (United States)

    Gross, Briana L; Henk, Adam D; Bonnart, Remi; Volk, Gayle M

    2017-03-01

    Transcripts related to abiotic stress, oxidation, and wounding were differentially expressed in Arabidopsis shoot tips in response to cryoprotectant and liquid nitrogen treatment. Cryopreservation methods have been implemented in genebanks as a strategy to back-up plant genetic resource collections that are vegetatively propagated. Cryopreservation is frequently performed using vitrification methods, whereby shoot tips are treated with cryoprotectant solutions, such as Plant Vitrification Solution 2 (PVS2) or Plant Vitrification Solution 3 (PVS3); these solutions remove and/or replace freezable water within the meristem cells. We used the model system Arabidopsis thaliana to identify suites of transcripts that are up- or downregulated in response to PVS2 and PVS3 treatment and liquid nitrogen (LN) exposure. Our results suggest that there are many changes in transcript expression in shoot tips as a result of cryoprotection and that these changes exceed the number detected as a result of LN exposure. In total, 180 transcripts showed significant changes in expression level unique to treatment with either the cryoprotectant or cryopreservation followed by recovery. Of these 180 transcripts, 67 were related to stress, defense, wounding, lipid, carbohydrate, abscisic acid, oxidation, temperature (cold/heat), or osmoregulation. The responses of five transcripts were confirmed using qPCR methods. The transcripts responding to PVS2 + LN suggest an oxidative response to this treatment, whereas the PVS3 + LN treatment invoked a more general metabolic response. This work shows that the choice of cryoprotectant can have a major influence on the patterns of transcript expression, presumably due to the level and extent of stress experienced by the shoot tip. As a result, there may be divergent responses of study systems to PVS2 and PVS3 treatments.

  17. Effect of 60Co γ irradiation with seed and shoot-tip of Brassica campestris L. var on its culture in vitro

    International Nuclear Information System (INIS)

    Liao Feixiong; Yu Rangcai; Pan Ruichi

    2003-01-01

    The survival rate in vitro of shoot-tips of Brassica campestris L. var from seeds irradiated by 60 Co γ-rays decreased with the increase of dose. Irradiation inhibited proliferation of shoot-tip, induction of callus from cotyledons and differentiation of the callus. The age of explant contributed to the effect of irradiation in the culture. Irradiation stimulated the proliferation of shoot-tip with dose less than 50 Gy. Based on the effect of irradiation in the tissue culture, the effective dose recommended was about 200 Gy for seeds, 50-100 Gy for pre-soaked germinating seeds and 40-70 Gy for shoot-tips in vitro, respectively

  18. The Sandy Hook Elementary School shooting as tipping point: "This Time Is Different".

    Science.gov (United States)

    Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M

    2013-01-01

    Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States.

  19. Structural and functional organization of growing tips of Neurospora crassa Hyphae.

    Science.gov (United States)

    Potapova, T V

    2014-07-01

    Data are presented on a variety of intracellular structures of the vegetative hyphae of the filamentous fungus Neurospora crassa and the involvement of these structures in the tip growth of the hyphae. Current ideas on the molecular and genetic mechanisms of tip growth and regulation of this process are considered. On the basis of comparison of data on behaviors of mitochondria and microtubules and data on the electrical heterogeneity of the hyphal apex, a hypothesis is proposed about a possible supervisory role of the longitudinal electric field in the structural and functional organization of growing tips of the N. crassa hyphae.

  20. Rapid in vitro propagation system through shoot tip cultures of Vitex trifolia L.-an important multipurpose plant of the Pacific traditional Medicine.

    Science.gov (United States)

    Ahmed, Rafique; Anis, Mohammad

    2014-07-01

    A rapid and efficient plant propagation system through shoot tip explants was established in Vitex trifolia L., a medicinally important plant belonging to the family Verbenaceae. Multiple shoots were induced directly on Murashige and Skoog (MS) medium consisting of different cytokinins, 6-benzyladenine (BA), kinetin (Kin) and 2-isopentenyl adenine (2-iP), BA at an optimal concentration of 5.0 μM was most effective in inducing multiple shoots where 90 % explants responded with an average shoot number (4.4±0.1) and shoot length (2.0±0.1 cm) after 6 weeks of culture. Inclusion of NAA in the culture medium along with the optimum concentration of BA promoted a higher rate of shoot multiplication and length of the shoot, where 19.2±0.3 well-grown healthy shoots with an average shoot length of 4.4±0.1 cm were obtained on completion of 12 weeks culture period. Ex vitro rooting was achieved best directly in soilrite when basal portion of the shoots were treated with 500 μM indole-3-butyric acid for 15 min which was the most effective in inducing roots, as 95 % of the microshoots produced roots. Plantlets went through a hardening phase in a controlled plant growth chamber, prior to ex-vitro transfer. Micropropagated plants grew well, attained maturity and flowered with 92 % survival rate. The results of this study provide the first report on in vitro plant regeneration of Vitex trifolia L. using shoot tip explants.

  1. Plant regeneration of bananas Ambon kuning and Barangan mutant lines were carried out by using female organ and shoot-tip as explants source

    International Nuclear Information System (INIS)

    Dewi, Azri K; Ishak

    1998-01-01

    Plant regeneration of bananas Ambon Kuning and Barangan mutant lines were carried out by using female organ and shoot-tip as explants source. Female organ was taken from heart of banana stem, while shoot-tip taken from sucker in banana plantation at Pasar Jumat, Jakarta. Those explants were cultured on MS medium containing 3 mg/l BAP, 0.5 mg/l IAA and supplemented by 100 tyrosin and 80 mg/l adenin hemisulphate. Observation showed that 180 and 42 buds were obtained from JBR 02 mutant lines respectively, while 84 and 79 buds for JAK 01 and JAK 02 respectively. The highest shoot formation was 1.013 shoots were obtained from BRC variety and lowest one was JBR 01 mutant line. statistical data analysis indicated that shoot formation between BRC variety and another mutant lines were significant difference using LSD test at level 0.05. Plantlet formation derived from female organ as well as shoot-tip showed that BRC variety produced number of plantlets per bottle was higher that another one. (author)

  2. LONG-TERM PRECONDITIONING OF PLANTLETS: A PRACTICAL METHOD FOR ENHANCING SURVIVAL OF PINEAPPLE (Ananas comosus Merr.) SHOOT TIPS CRYOPRESERVED USING VITRIFICATION.

    Science.gov (United States)

    Hu, W H; Liu, S F; Liaw, S I

    2015-01-01

    The purpose of this study was to develop an efficient cryopreservation protocol for pineapple (Ananas comosus Merr.) shoot tips. The optimal state of pineapple plantlets was investigated by using sucrose preconditioning to enhance survival after cryostorage. To achieve a suitable state of plantlets before cryopreservation, 0.2 M to 0.4 M sucrose concentrations combined with short- (0-7 days), medium- (15-30 days), and long-term (75-150 days) preconditioning periods were compared. The highest survival (100 %) was achieved using the following procedure: intact plantlets underwent long-term preconditioning with 0.2 M sucrose for 135 days, dissected shoot tips were treated with a loading solution containing 2.0 M glycerol + 0.4 M sucrose for 60 min at 25 degree and the shoot tips were dehydrated in PVS2 for 2h at 0 degree C before being plunged in liquid nitrogen. Rewarming was conducted in a water-bath for 30 s at 40 degree C and PVS2 was replaced with a 1.2 M sucrose solution for 30 min at 25 degree C. The shoot tips were transferred on semisolid medium and left in the dark for 1 week, then in dim light for 3 weeks.

  3. Cryopreservation of chayote (Sechium edule JACQ. SW.) zygotic embryos and shoot-tips from in vitro plantlets.

    Science.gov (United States)

    Abdelnour-Esquivel, Ana; Engelmann, Florent

    2002-01-01

    This paper presents the development of cryopreservation protocols for zygotic embryos and apices of chayote (Sechium edule Jacq. Sw.), a tropical plant species with recalcitrant seeds. Zygotic embryos of two cultivars, Ccocro negro (CN) and Claudio (Cl) could withstand cryopreservation, with survival percentages of 10 and 30 %, after desiccation to 23 and 19 % moisture content (fresh weight basis), respectively. Apices sampled on in vitro plantlets of cultivars Cl, 13 and JM were successfully cryopreserved using a vitrification technique. Optimal conditions included the culture of mother-plants for 22 days on medium containing 0.3 M sucrose, culture of excised apices on the same medium for 1 day, loading of apices for 20 min with 2M glycerol + 0.4M glycerol, treatment with a series of diluted PVS2 solution (60 % PVS2 followed by 80 % PVS2 solution for 15 min (cultivar Cocoro Blanco [CB]) or 30 min (cultivars CN and Cl) at each concentration), rapid freezing and thawing, washing of shoot-tips with a 1.2 M sucrose solution, followed by recovery on media with progressively decreasing sucrose concentrations until the standard concentration of 0.1 M was reached. The highest survival percentages achieved ranged between 17 and 38 %, depending on the cultivar.

  4. Distribution of indole-3-acetic acid in Petunia hybrida shoot tip cuttings and relationship between auxin transport, carbohydrate metabolism and adventitious root formation.

    OpenAIRE

    Ahkami, Amir H.; Melzer, Michael; Ghaffari, Mohammad R.; Pollmann, Stephan; Ghorbani, Majid; Shahinnia, Fahimeh; Hajirezaei, Mohammad R.; Druege, Uwe

    2013-01-01

    To determine the contribution of polar auxin transport (PAT) to auxin accumulation and to adventitious root (AR) formation in the stem base of Petunia hybrida shoot tip cuttings, the level of indole-3-acetic acid (IAA) was monitored in non-treated cuttings and cuttings treated with the auxin transport blocker naphthylphthalamic acid (NPA) and was complemented with precise anatomical studies. The temporal course of carbohydrates, amino acids and activities of controlling enzymes was also inves...

  5. Investigation of plant hormone level changes in shoot tips of longan (Dimocarpus longan Lour.) treated with potassium chlorate by liquid chromatography-electrospray ionization mass spectrometry.

    Science.gov (United States)

    Susawaengsup, Chanthana; Rayanakorn, Mongkon; Wongpornchai, Sugunya; Wangkarn, Sunanta

    2011-08-15

    The endogenous levels of indole-3-acetic acid (IAA), gibberellins (GAs), abscisic acid (ABA) and cytokinins (CKs) and their changes were investigated in shoot tips of ten longan (Dimocarpus longan Lour.) trees for off-season flowering until 60 days after potassium chlorate treatment in comparison with those of ten control (untreated) longan trees. These analytes were extracted and interfering matrices removed with a single mixed-mode solid phase extraction under optimum conditions. The recoveries at three levels of concentration were in the range of 72-112%. The endogenous plant hormones were separated and quantified by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). Detection limits based on the signal-to-noise ratio ranged from 10 ng mL(-1) for gibberellin A4 (GA4) to 200 ng mL(-1) for IAA. Within the first week after potassium chlorate treatment, dry weight (DW) amounts in the treated longan shoot tips of four gibberellins, namely: gibberellin A1(GA1), gibberellic acid (GA3), gibberellin A19 (GA19) and gibberellin A20 (GA20), were found to increase to approximately 25, 50, 20 and 60 ng g(-1) respectively, all of which were significantly higher than those of the controls. In contrast, gibberellin A8 (GA8) obtained from the treated longan was found to decrease to approximately 20 ng g(-1)DW while that of the control increased to around 80 ng g(-1)DW. Certain CKs which play a role in leaf bud induction, particularly isopentenyl adenine (iP), isopentenyl adenosine (iPR) and dihydrozeatin riboside (DHZR), were found to be present in amounts of approximately 20, 50 and 60 ng g(-1)DW in the shoot tips of the control longan. The analytical results obtained from the two-month off-season longan flowering period indicate that high GA1, GA3, GA19 and GA20 levels in the longan shoot tips contribute to flower bud induction while high levels of CKs, IAA and ABA in the control longan contribute more to the vegetative development. Copyright © 2011

  6. [TIPS

    Science.gov (United States)

    Brazzini, Augusto; Carrillo, Alvaro; Cantella, Raúl

    1998-01-01

    Esophageal hemorrage due to variceal bleeding in cirrhotic patients represents a serious problem for the physician in charge, especially in this country where liver transplants are inexistent; and also, it is a drama for the patient and its familly. We propose here the Transjugular Intrahepatic Portosystemic Shunt (TIPS). Twenty one patients were part of a study where 23 TIPS were placed, observing an immediate improval in 18 of them, a rebleeding in 2, within the first 24 and 48 hours. An embolization of the coronary veins was performed in the procedure in 15 patients, and a second intervention due to rebleeding in 2 of them. In the latter patients, the embolization of the coronary veins was rutinary.The survival of the patients has been outstanding.We conclude that this interventional procedure is a worldwide reality in the treatment of esophageal hemorrage by variceal bleeding due to portal hipertension, and it does not cut down the probability of liver transplant, unfortunately inexistent in our country. This procedure results in a low morbimortality with an adequate quality of life.

  7. Radiosensitivity, mutation and tetraploid induction in the gamma-ray-irradiated growing shoots in mulberry, Morus alba L

    International Nuclear Information System (INIS)

    Katagiri, Koitsu

    1976-01-01

    The vigorously developing mulberry shoots on the 1 year old grafted trees of the variety Inchinose were separately exposed to 60 Co γ-ray of 6KR at 120 R/hr and 7.5 KR at 150 R/hr in early July, early August and early September. After the irradiation, all of the irradiated shoots developed axially buds with malformed narrow leaves, and after that, all plants subjected to the irradiation in September and 30% of the July irradiation group and 40% of the August irradiation group both with higher exposure ceased shoot development. This type of radiation damage was large for the plants with higher exposure as compared with those with lower one, and it was also severe for the plants irradiated in July in comparison with those in August. From the ceasing of shoot development the LD 50 value of 150 R/hr irradiation was estimated to be a little more than 7.5 KR. The frequencies of mutation and tetraploid in the grafts produced by the propagation of the axially buds below the leafless portion were high in the grafts with higher exposure than those with lower one, and also the frequencies were high in July irradiation in comparison with August irradiation. It was confirmed that the size of mutation or tetraploid sector was large in the shoots derived from the less advanced axially bud primordia at the time of irradiation than that from the advanced ones. All of tetraploids were the cytochimeras having diploid epidermises over tetraploid internal tissues. (Kobatake, H.)

  8. In vitro Embryogenesis Derived from Shoot Tips in Mass Propagation of Two Selected-Clones of Phalaenopsis

    Directory of Open Access Journals (Sweden)

    Budi WINARTO

    2016-09-01

    Full Text Available Phalaenopsis is of high economic value and market demand in Indonesia; however, orchid products are mostly imported from other countries. ‘Kristina Dwi’ (KD 69.274 and ‘Dedeh’ (D 802.28 are two selected clones with high potential utilized and developed commercially. To support their commercialization, a reliable in vitro propagation protocol is essential.  In the current study, an in vitro mass propagation protocol for KD 69.274 and D 802.28 clones was successfully established using shoot tips as explant sources. A high number of embryos, up to 8.2 embryos per explant, with 58.5% explant regeneration, and 3.5 regenerated-explants in average were regenerated from shoot tips of KD 69.274 clone cultured on  half-strength Murashige and Skoog (MS medium, with full strength micro, Fe-chellate and vitamin containing 0.5 mg/L thidiazuruon (TDZ and 0.25 mg/L N6-benzyladenine (BA. The initial embryos were proliferated by culturing embryos individually on half-strength MS medium with 0.13 mg/L TDZ and 0.25 mg/L BA and resulted in high embryo regeneration up to 91.4%, with 10.2 embryos per explant and no embryo browning. The embryos were multiplied under periodical subcultures of 3 months each, resulting in gradual increasing number of embryos from the first subculture till the fifth subculture, with 23.6 embryos produced, then declined afterward. The embryos were easily germinated on half-strength MS medium with full strength of vitamin and hormone free, with 73.9% embryo germination and 14.9 germinated embryos. Healthy plantlets were stimulated on the same medium with 2 g/L activated charcoal (AC and successfully acclimatized on Cycas rumphii bulk, with 88.3% survival plantlets. Finally, it can be summarized that a new in vitro mass propagation protocol, as new alternative choice for Phalaenopsis propagation, was successfully established.

  9. HPLC-UV-ESI-MS analysis of phenolic compounds and antioxidant properties of Hypericum undulatum shoot cultures and wild-growing plants.

    Science.gov (United States)

    Rainha, Nuno; Koci, Kamila; Coelho, Ana Varela; Lima, Elisabete; Baptista, José; Fernandes-Ferreira, Manuel

    2013-02-01

    LC-UV and LC-MS analysis were used to study the phenolic composition of water extracts of Hypericum undulatum (HU) shoot cultures and wild-growing (WG) plants. Total phenolic content (TPC), determined using the Folin-Ciocalteu assay, and the antioxidant activity measured by two complementary methods were also performed for each sample. Mass spectrometry revealed several phenolics acids with quinic acid moieties, flavonols, mostly quercetin, luteolin and apigenin glycosides, flavan-3-ols (catechin and epicatechin) and the xanthonoid mangiferin. Differences in phenolic composition profile and TPC were found between the samples. The major phenolic in HU culture-growing (CG) samples is chlorogenic acid, followed by epicatechin, quercitrin and isoquercitrin. The WG plants presents hyperoside as the main phenolic, followed by isoquercitrin, chlorogenic acid and quercetin. The TPC and antioxidant activity were higher in samples from WG plants. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. The Evaluation of the Effect of Multiwall Carbon Nano Tube (MWCNT) on In Vitro Proliferation and Shoot Tip Necrosis of Pistachio Rootstock UCB-1 (Pistacia integrima × P. atlantica)

    OpenAIRE

    Shahrzad Aghasi Kermani; Hossein Hokmabadi; Marzieh Ghanbari Jahromi

    2017-01-01

    UCB-1 (Pistacia atlantica × P. integrima) is a commercial rootstock for pistachio in some pistachio plantations across the world. This rootstock is very new in Iran and recently, it has been used commercially in some plantations due to its high growth. Propagation of this rootstock by tissue culture results in many limitations such as shoot tip necrosis (STN) and a low proliferation rate. Therefore, any process that leads to improve the proliferation rate and feature will be used in commercia...

  11. A termite symbiotic mushroom maximizing sexual activity at growing tips of vegetative hyphae.

    Science.gov (United States)

    Hsieh, Huei-Mei; Chung, Mei-Chu; Chen, Pao-Yang; Hsu, Fei-Man; Liao, Wen-Wei; Sung, Ai-Ning; Lin, Chun-Ru; Wang, Chung-Ju Rachel; Kao, Yu-Hsin; Fang, Mei-Jane; Lai, Chi-Yung; Huang, Chieh-Chen; Chou, Jyh-Ching; Chou, Wen-Neng; Chang, Bill Chia-Han; Ju, Yu-Ming

    2017-09-19

    Termitomyces mushrooms are mutualistically associated with fungus-growing termites, which are widely considered to cultivate a monogenotypic Termitomyces symbiont within a colony. Termitomyces cultures isolated directly from termite colonies are heterokaryotic, likely through mating between compatible homokaryons. After pairing homokaryons carrying different haplotypes at marker gene loci MIP and RCB from a Termitomyces fruiting body associated with Odontotermes formosanus, we observed nuclear fusion and division, which greatly resembled meiosis, during each hyphal cell division and conidial formation in the resulting heterokaryons. Surprisingly, nuclei in homokaryons also behaved similarly. To confirm if meiotic-like recombination occurred within mycelia, we constructed whole-genome sequencing libraries from mycelia of two homokaryons and a heterokaryon resulting from mating of the two homokaryons. Obtained reads were aligned to the reference genome of Termitomyces sp. J132 for haplotype reconstruction. After removal of the recombinant haplotypes shared between the heterokaryon and either homokaryons, we inferred that 5.04% of the haplotypes from the heterokaryon were the recombinants resulting from homologous recombination distributed genome-wide. With RNA transcripts of four meiosis-specific genes, including SPO11, DMC1, MSH4, and MLH1, detected from a mycelial sample by real-time quantitative PCR, the nuclear behavior in mycelia was reconfirmed meiotic-like. Unlike other basidiomycetes where sex is largely restricted to basidia, Termitomyces maximizes sexuality at somatic stage, resulting in an ever-changing genotype composed of a myriad of coexisting heterogeneous nuclei in a heterokaryon. Somatic meiotic-like recombination may endow Termitomyces with agility to cope with termite consumption by maximized genetic variability.

  12. The Mechanism Forming the Cell Surface of Tip-Growing Rooting Cells Is Conserved among Land Plants.

    Science.gov (United States)

    Honkanen, Suvi; Jones, Victor A S; Morieri, Giulia; Champion, Clement; Hetherington, Alexander J; Kelly, Steve; Proust, Hélène; Saint-Marcoux, Denis; Prescott, Helen; Dolan, Liam

    2016-12-05

    To discover mechanisms that controlled the growth of the rooting system in the earliest land plants, we identified genes that control the development of rhizoids in the liverwort Marchantia polymorpha. 336,000 T-DNA transformed lines were screened for mutants with defects in rhizoid growth, and a de novo genome assembly was generated to identify the mutant genes. We report the identification of 33 genes required for rhizoid growth, of which 6 had not previously been functionally characterized in green plants. We demonstrate that members of the same orthogroup are active in cell wall synthesis, cell wall integrity sensing, and vesicle trafficking during M. polymorpha rhizoid and Arabidopsis thaliana root hair growth. This indicates that the mechanism for constructing the cell surface of tip-growing rooting cells is conserved among land plants and was active in the earliest land plants that existed sometime more than 470 million years ago [1, 2]. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Growing different Lactuca genotypes aeroponically within a tropical greenhouse – Cool rootzone temperatures decreased rootzone ethylene concentrations and increased shoot growth

    Directory of Open Access Journals (Sweden)

    Tsui Wei CHOONG

    2016-09-01

    Full Text Available Temperate crops cannot grow well in the tropics without rootzone cooling. As cooling increased production costs, this experiment aimed to study the growth of various Lactuca genotypes and propose possible ways of reducing these costs, without compromising productivity. A recombinant inbred line (RIL of lettuce and its parental lines (L. serriola and L. sativa ‘Salinas’ were grown aeroponically in a tropical greenhouse under 24 C cool (C or warm fluctuating 30-36 C ambient (A rootzone temperature (RZT. Their roots were misted with Netherlands standard nutrient solution for 1 min, at intervals of either 5 min (A5, C5 or 10 min (A10, C10 in attempting to reduce electricity consumption and production costs. Lower mortality and higher productivity were observed in all genotypes when grown in C-RZT. Higher shoot fresh weight was observed under C5 than C10, for the RIL and L. serriola. Since ‘Salinas’ had similar shoot fresh weight at both C-RZ treatments, this may indicate it is more sensitive to RZT than water availability. Under A-RZ treatments, higher carotenoid content, with correspondingly higher nonphotochemical quenching, was observed in A10 for the RIL and ‘Salinas’. Further, total chlorophyll content was also highest at this RZ treatment for the RIL though photochemical quenching was contrastingly the lowest. Cumulatively, productivity was compromised at A10 as the RIL seemed to prioritize photoprotection over efficiency in photosynthesis, under conditions of higher RZT and lower water availability. Generally, higher RZ ethylene concentrations accumulated in A10 and C10 than A5 and C5, respectively – probably due to spray frequency exerting a greater effect on RZ ethylene accumulation than RZT. In the C5 RZ treatment, lowest RZ ethylene concentration corresponded with highest shoot fresh weight. As such, further research on ethylene (insensitivity and water use efficiency could be conducted to identify Lactuca cultivars

  14. Studies on the tissue culture of Stevia rebaudiana and its components; (II). Induction of shoot primordia.

    Science.gov (United States)

    Miyagawa, H; Fujioka, N; Kohda, H; Yamasaki, K; Taniguchi, K; Tanaka, R

    1986-08-01

    Shoot primordia, which were able to propagate vegetatively with a very high rate and to redifferentiate easily to new plants, were induced from shoot tips of Stevia rebaudiana Bertoni on Gamborg B5 medium containing 6-benzylaminopurine (BAP) and alpha-naphthaleneacetic acid (NAA) under light. The propagation of the shoot primordia of Stevia rebaudiana is rapid, and they are highly stable in chromosome number and karyotype. The shoot primordia can propagate at a high rate for a long time without differentiation. At any time, the shoot primordia readily developed into plantlets with shoots and roots within 2 or 3 weeks in static culture on B5 medium containing 0.02 mg/l BAP and 2% sucrose. The plantlets were transplanted to sterilized soil to grow to normal adult plants.

  15. Enhanced in vitro multiple shoot induction in elite Pakistani guava ...

    African Journals Online (AJOL)

    Elite guava (Psidium guajava L.) strains of cv. Safeda were explored in vitro for multiple shoot induction. Shoot induction was enhanced up to 83% with 3.5 to 4.25 shoots per single node cutting and shoot tip explants, respectively, using higher levels of benzyl amino purine (BAP) in Murashige and Skoog (MS) medium.

  16. The Evaluation of the Effect of Multiwall Carbon Nano Tube (MWCNT on In Vitro Proliferation and Shoot Tip Necrosis of Pistachio Rootstock UCB-1 (Pistacia integrima × P. atlantica

    Directory of Open Access Journals (Sweden)

    Shahrzad Aghasi Kermani

    2017-05-01

    Full Text Available UCB-1 (Pistacia atlantica × P. integrima is a commercial rootstock for pistachio in some pistachio plantations across the world. This rootstock is very new in Iran and recently, it has been used commercially in some plantations due to its high growth. Propagation of this rootstock by tissue culture results in many limitations such as shoot tip necrosis (STN and a low proliferation rate. Therefore, any process that leads to improve the proliferation rate and feature will be used in commercial propagation of this rootstock. Nanotubes are widely used in in vitro cultures. For this reason, we used different concentrations of carbon nanotubes (0, 50, 100, 150, 200 µg/l and benzyladenine (0, 0.5, 1, 1.5 and 2 mg/l to improve the proliferation rate and qualitative indices. The results showed that using carbon nanotubes concentration of 200 µg/l with 2mg/l of benzyladenine (BA led to maximum proliferation (4 microshoots per explant, maximum shoot length (3.68 cm and minimum STN (8% and vitrification (this isn’t a word? (0 % percentage.

  17. Plant root and shoot dynamics during subsurface obstacle interaction

    Science.gov (United States)

    Conn, Nathaniel; Aguilar, Jeffrey; Benfey, Philip; Goldman, Daniel

    As roots grow, they must navigate complex underground environments to anchor and retrieve water and nutrients. From gravity sensing at the root tip to pressure sensing along the tip and elongation zone, the complex mechanosensory feedback system of the root allows it to bend towards greater depths and avoid obstacles of high impedance by asymmetrically suppressing cell elongation. Here we investigate the mechanical and physiological responses of roots to rigid obstacles. We grow Maize, Zea mays, plants in quasi-2D glass containers (22cm x 17cm x 1.4cm) filled with photoelastic gel and observe that, regardless of obstacle interaction, smaller roots branch off the primary root when the upward growing shoot (which contains the first leaf) reaches an average length of 40 mm, coinciding with when the first leaf emerges. However, prior to branching, contacts with obstacles result in reduced root growth rates. The growth rate of the root relative to the shoot is sensitive to the angle of the obstacle surface, whereby the relative root growth is greatest for horizontally oriented surfaces. We posit that root growth is prioritized when horizontal obstacles are encountered to ensure anchoring and access to nutrients during later stages of development. NSF Physics of Living Systems.

  18. Shooting stars

    International Nuclear Information System (INIS)

    Maurette, M.; Hammer, C.

    1985-01-01

    A shooting star passage -even a star shower- can be sometimes easily seen during moonless black night. They represent the partial volatilization in earth atmosphere of meteorites or micrometeorites reduced in cosmic dusts. Everywhere on earth, these star dusts are searched to be gathered. This research made one year ago on the Greenland ice-cap is this article object; orbit gathering projects are also presented [fr

  19. Shoot tip culture and thermotherapy for recovering virus-free plants of garlic Cultura de ápices caulinares e termoterapia na recuperação de plantas livres de vírus de alho

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Torres

    2000-11-01

    Full Text Available Garlic shoot tip culture associated with dry heat thermotherapy (cloves exposed to 37°C for 35 days were essential for recovering virus free plants of the cv Amarante. In this condition 70% of the explants developed in vitro and produced plants. A total of 77% of those plants was virus free when indexed by ISEM, which resulted in a final index of 54% of virus free plants from treated cloves. The percentage of regeneration decreased to 20% as the temperature increased up to 40°C. However 90% of those plants were virus free, leading to a final index of 18% virus free plants out of treated cloves.A cultura de ápices caulinares de alho, associada à termoterapia a seco (exposição dos bulbilhos a temperatura de 37°C, por um período de 35 dias foi essencial para recuperação de plantas livres de vírus das cultivar de alho Amarante. Nestas condições, 70% dos explantes inoculados se desenvolveram in vitro e produziram plantas, das quais 77% não apresentaram partículas virais quando indexadas por ISEM. Isto resulta em um índice de aproveitamento de 54% dos bulbilhos submetidos à termoterapia. O aumento da temperatura na termoterapia para 40°C reduziu a regeneração in vitro para 20%, e 90% dessas plantas estavam livres de vírus, com um índice final de aproveitamento de 18%.

  20. Transfer of metals and metalloids from soil to shoots in wild rosemary (Rosmarinus officinalis L.) growing on a former lead smelter site: human exposure risk.

    Science.gov (United States)

    Affholder, Marie-Cécile; Prudent, Pascale; Masotti, Véronique; Coulomb, Bruno; Rabier, Jacques; Nguyen-The, Bénédicte; Laffont-Schwob, Isabelle

    2013-06-01

    This study aimed at estimating exposition risks to wild rosemary used as herbs in the contaminated area of the former smelting factory of L'Escalette (South of Marseille, France). Metals and metalloids i.e. Pb, As, Sb, Zn, and Cu concentrations were analyzed in soils and in rosemary aerial parts (stems and leaves) on two sites: one heavily contaminated and the other far away from the pollution source, considered as reference. The metal and metalloid transfer into water during the brewing process of herbal tea was also determined. A mixed contamination by the above-cited contaminants was demonstrated in soils of the factory site, with average concentrations of 9253, 1127, 309, 2698 and 32 mg/kg for Pb, As, Sb, Zn and Cu, respectively. However, metals and metalloids' transfer in rosemary aerial parts was limited, as bioaccumulation factors were under 1. Thus, Pb, As and Cu concentrations in leaves were below international regulation limits concerning ingestion of medicinal herbs (no regulation values available for Sb and Zn). This study highlighted that, if contaminated rosemary leaves were ingested, health risks may be limited since acceptable daily intake (ADI) for Pb, As, Sb and Cu (no ADI value available for Zn) will only be reached if very high quantities are consumed. Furthermore, we aimed to establish if this mixed contamination could alter rosemary's essential oil quality, and thereby the compositions of essential oils obtained from individuals on the heavily contaminated soil were compared to those obtained from the reference population. An increased biosynthesis of antioxidant compounds was favored in essential oils from rosemary individuals growing in contaminated site. Although the health risk of a long-term exposition of low level of the mixed contamination by rosemary ingestion is not easy to elucidate, the use of rosemary essential oils from contaminated site appears as safe. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. A role for CSLD3 during cell-wall synthesis in apical plasma membranes of tip-growing root-hair cells.

    Science.gov (United States)

    Park, Sungjin; Szumlanski, Amy L; Gu, Fangwei; Guo, Feng; Nielsen, Erik

    2011-07-17

    In plants, cell shape is defined by the cell wall, and changes in cell shape and size are dictated by modification of existing cell walls and deposition of newly synthesized cell-wall material. In root hairs, expansion occurs by a process called tip growth, which is shared by root hairs, pollen tubes and fungal hyphae. We show that cellulose-like polysaccharides are present in root-hair tips, and de novo synthesis of these polysaccharides is required for tip growth. We also find that eYFP-CSLD3 proteins, but not CESA cellulose synthases, localize to a polarized plasma-membrane domain in root hairs. Using biochemical methods and genetic complementation of a csld3 mutant with a chimaeric CSLD3 protein containing a CESA6 catalytic domain, we provide evidence that CSLD3 represents a distinct (1→4)-β-glucan synthase activity in apical plasma membranes during tip growth in root-hair cells.

  2. Tragedy and the Meaning of School Shootings

    Science.gov (United States)

    Warnick, Bryan R.; Johnson, Benjamin A.; Rocha, Samuel

    2010-01-01

    School shootings are traumatic events that cause a community to question itself, its values, and its educational systems. In this article Bryan Warnick, Benjamin Johnson, and Samuel Rocha explore the meanings of school shootings by examining three recent books on school violence. Topics that grow out of these books include (1) how school shootings…

  3. Shoot multiplication of Paphiopedilum orchid through in vitro cutting ...

    African Journals Online (AJOL)

    waraporn

    2012-09-20

    Sep 20, 2012 ... regulators could remain higher shoot multiplication than in other media. The micropropagation ... stalk nodes, buds, root tips and rhizome segments. For mass ... plants, the future mass-market orchids will most likely be.

  4. Tip Cells in Angiogenesis

    NARCIS (Netherlands)

    M.G. Dallinga (Marchien); S.E.M. Boas (Sonja); I. Klaassen (Ingeborg); R.M.H. Merks (Roeland); C.J.F. van Noorden; R.O. Schlingemann (Reinier)

    2015-01-01

    htmlabstractIn angiogenesis, the process in which blood vessel sprouts grow out from a pre-existing vascular network, the so-called endothelial tip cells play an essential role. Tip cells are the leading cells of the sprouts; they guide following endothelial cells and sense their environment for

  5. Use of embryogenic cell suspension and meristem-tip cultures for mutation breeding of apomictic Musa species

    International Nuclear Information System (INIS)

    Novak, F.J.; Afza, R.; Duren, M. van

    1990-01-01

    Full text: Breeding by crossing is difficult for banana and plantain. The plants are heterozygous, therefore mutagenic treatment may uncover a recessive allele by mutating or deleting a corresponding dominant allele. Meristem tips were excised from in vitro growing shoots and used for mutation experiments. Induction was carried out by irradiating shoot tips with γ rays and/or by treatment of explants with ethylmethanesulfonate (EMS). Cell suspension was initiated from corm and leaf tissue excised from in vitro grown plantlets. Mutagenised cell suspensions were derived from leaf and corm tissues irradiated with 60 Co γ rays - (10 to 60 Gy, 8 Gy/min). Musa clones exhibited differences in radiosensitivity and post-irradiation recovery. Doses of 20 to 40 Gy seem suitable for mutation induction. The EMS concentration of 25 mM for 4 hours was found effective for isolated shoot tips. Considerable phenotypic variation was observed among plants regenerated from in vitro shoot tips after mutagenic treatment. Leaf and corm explants kept their morphogenic ability in embryogenic cell suspensions after irradiation up to 25 Gy. (author)

  6. Tips for TIPS

    NARCIS (Netherlands)

    Cuijpers, C.F.

    2015-01-01

    The transjugular intrahepatic portosystemic shunt (TIPS) procedure is one of the most technically challenging procedures in interventional radiology. During the procedure, interventional radiologists (IRs) insert very thin and long instruments through a little incision in the patient’s neck. They

  7. Sirococcus Shoot Blight

    Science.gov (United States)

    Thomas H. Nicholls; Kathryn Robbins

    1984-01-01

    Sirococcus shoot blight, caused by the fungus Sirococcus strobilinus Preuss, affects conifers in the Northern United States and southern Canada. The fungus infects the new shoots; diseased seedlings and saplings are especially affected. In the United States, sirococcus shoot blight has become increasingly widespread since the early 1970's. When favorable...

  8. Cell fate regulation in the shoot meristem.

    Science.gov (United States)

    Laux, T; Mayer, K F

    1998-04-01

    The shoot meristem is a proliferative centre containing pluripotent stem cells that are the ultimate source of all cells and organs continuously added to the growing shoot. The progeny of the stem cells have two developmental options, either to renew the stem cell population or to leave the meristem and to differentiate, possibly according to signals from more mature tissue. The destiny of each cell depends on its position within the dynamic shoot meristem. Genetic data suggest a simple model in which graded positional information is provided by antagonistic gene functions and is interpreted by genes which regulate cell fate.

  9. Tipping Point

    Medline Plus

    Full Text Available ... death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ... tv tip-overs. The force of a large television falling from tipping furniture can be staggering. A ...

  10. CPAP Tips

    Science.gov (United States)

    ... now Try it free Find out why Close CPAP Tips from FDA USFoodandDrugAdmin Loading... Unsubscribe from USFoodandDrugAdmin? ... apnea and use a continuous positive airway pressure (CPAP) device when sleeping? Here are some tips from ...

  11. Tipping Point

    Medline Plus

    Full Text Available ... and furniture, appliance and tv tip-overs. The force of a large television falling from tipping furniture ... 50 lb. TV falls with about the same force as child falling from the third story of ...

  12. Tipping Point

    Medline Plus

    Full Text Available ... Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture ... about horrible accidents involving young children and furniture, appliance and tv tip-overs. The force of a ...

  13. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  14. Shooting mechanisms in nature

    NARCIS (Netherlands)

    Sakes, Aimée; Wiel, van der Marleen; Henselmans, Paul W.J.; Leeuwen, van Johan L.; Dodou, Dimitra; Breedveld, Paul

    2016-01-01

    Background In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

  15. CPAP Tips

    Medline Plus

    Full Text Available ... now Try it free Find out why Close CPAP Tips from FDA USFoodandDrugAdmin Loading... Unsubscribe from USFoodandDrugAdmin? ... apnea and use a continuous positive airway pressure (CPAP) device when sleeping? Here are some tips from ...

  16. Technology Tips

    Science.gov (United States)

    Mathematics Teacher, 2004

    2004-01-01

    Some inexpensive or free ways that enable to capture and use images in work are mentioned. The first tip demonstrates the methods of using some of the built-in capabilities of the Macintosh and Windows-based PC operating systems, and the second tip describes methods to capture and create images using SnagIt.

  17. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

  18. Tipping Point

    Medline Plus

    Full Text Available ... 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  19. Effects of BAP and TIBA on Shoot Proliferation of Rosa hybrida L. cv. Full House in in vitro Culture

    Directory of Open Access Journals (Sweden)

    S. Hajian

    2016-02-01

    Full Text Available Micropropagation is a proper approach to rapid and large-scale propagation of rootstocks and rose cultivars for huge demand of flower market. Proliferation rate of shoot is decreased drastically following several subcultures. Growth regulators have remarkable effects on the key phase of proliferation in micropropagation of this popular crop. In this research the effects of BAP and antiauxin of TIBA on quality and quantity of developed shoots in Rosa hybrida cv. Full House were studied. BAP and TIBA were applied at three concentrations of 0, 2.2 and 8.8 µmol in proliferation phase of micropropagation. The experiment was conducted based on factorial and completely randomized design with four replications. After two months, the percentage of proliferated explants, survived main and lateral shoot number, length of the main and lateral shoots, number of green leaves on the shoots, the average number of shoots with chlorotic and necrotic leaves, the average axillary shoot base diameter, fresh weight of shoots and number of shoots with necrotic tip were recorded. Analysis of variance indicated that BAP was ineffective on the number of the main shoot green leaves and decreasing number of shoots with necrotic tip, but enhanced other traits. The concentration of 8.8 µmol of BAP had greater effect than 2.2 µmol of this growth regulator on mentioned traits. The higher concentration of TIBA resulted to more shoot with necrotic tip. This antiauxin had anegative impact on shoot fresh weight, but the other parameters were not significantly affected.

  20. Violence and school shootings.

    Science.gov (United States)

    Flannery, Daniel J; Modzeleski, William; Kretschmar, Jeff M

    2013-01-01

    Multiple-homicide school shootings are rare events, but when they happen they significantly impact individuals, the school and the community. We focus on multiple-homicide incidents and identified mental health issues of shooters. To date, studies of school shootings have concluded that no reliable profile of a shooter exists, so risk should be assessed using comprehensive threat assessment protocols. Existing studies primarily utilize retrospective case histories or media accounts. The field requires more empirical and systematic research on all types of school shootings including single victim incidents, those that result in injury but not death and those that are successfully averted. We discuss current policies and practices related to school shootings and the role of mental health professionals in assessing risk and supporting surviving victims.

  1. Tipping Point

    Medline Plus

    Full Text Available ... fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash format. Almost ... accidents involving young children and furniture, appliance and tv tip-overs. The force of a large television ...

  2. Tipping Point

    Medline Plus

    Full Text Available ... of a large television falling from tipping furniture can be staggering. A 50 lb. TV falls with ... story of a building. That kind of impact can kill a child or cause severe injuries. About ...

  3. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... see news reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The ...

  4. CPAP Tips

    Medline Plus

    Full Text Available ... sleeping? Here are some tips from the U.S. Food and Drug Administration (FDA) on how to safely and effectively use your CPAP device. Category Education License Standard YouTube License Show more Show ...

  5. CPAP Tips

    Medline Plus

    Full Text Available ... opinion count. Sign in ... and use a continuous positive airway pressure (CPAP) device when sleeping? Here are some tips from the U.S. Food and Drug Administration (FDA) on how to safely ...

  6. Tipping Point

    Medline Plus

    Full Text Available ... third story of a building. That kind of impact can kill a child or cause severe injuries. ... to prevent a tip-over tragedy. Share Post Facebook Twitter Google Plus Reddit Connect with Me:  Visit ...

  7. Enzyme-Linked Immunosorbent Assay Testing of Shoots Grown In Vitro and the Use of Immunocapture-Reverse Transcription-Polymerase Chain Reaction Improve the Detection of Prunus necrotic ringspot virus in Rose.

    Science.gov (United States)

    Moury, B; Cardin, L; Onesto, J P; Candresse, T; Poupet, A

    2000-05-01

    We developed and evaluated two different methods to improve the detection of the most prevalent virus of rose in Europe, Prunus necrotic ring-spot virus (PNRSV). Immunocapture-reverse transcription-polymerase chain reaction was estimated to be about 100 times more sensitive than double-antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) and showed an equivalent specificity. Based on the observation that PNRSV multiplies actively in young growing tissues (axillary shoots and cuttings), an in vitro culture method allowing rapid (about 15 days) and homogeneous development of dormant axillary buds with high virus titers was standardized. ELISA tests of these young shoots showed, in some cases, a 10(4) to 10(5) increase in sensitivity in comparison to adjacent leaf tissues from the rose mother plants. Between 21 and 98% (depending on the season) more samples were identified as positive by using ELISA on samples from shoot tips grown in vitro rather than on leaves collected directly from the PNRSV-infected mother plants. This simple method of growing shoot tips in vitro improved the confidence in the detection of PNRSV and eliminated problems in sampling appropriate tissues.

  8. Effects of thidiazuron and paclobutrazol on regeneration potential of tulip flower stalk explants in vitro and subsequent shoot multiplication

    Directory of Open Access Journals (Sweden)

    Małgorzata Podwyszyńska

    2011-01-01

    Full Text Available The effects of TDZ and paclobutrazol on the primary regeneration on tulip flower stalk explants of six cultivars and subsequent shoot multiplication were examined. Explants, flower stalk slices, were excised from cooled and subsequently forced bulbs. The explants were incubated for two months in darkness on medium containing NAA and cytokinins, 2iP and BAP, as control, or TDZ (0.5-4 mg l-1 and paclobutrazol (0.05-0.4 mg l-1. Then, the regenerating explants were subcultured on medium with TDZ and NAA applied at low concentrations. Different regeneration capabilities were found depending on cultivar and growth regulators. The percentage of explants forming leaf-like structures ranged, on the control medium, from 80% in 'Blue Parrot' and 'Prominence' to below 30% in 'Apeldoorn' and 'Mirjoran'. TDZ, applied at optimum for each cultivar concentration, greatly increased the regeneration potential up to 70-100%. Paclobutrazol, added to the TDZ-containing medium, significantly enhanced the response of explants, resulting in high numbers of leaf-like structures formed per explant (13.7-22.8. The structures developed gradually into characteristic forms: the growing up cotyledonary leaf, the probable root primordium formed at its base, the growing downwards stolon and the shoot meristem developed finely on its tip. It is suggested that such primary regeneration may have a nature of somatic embryogenesis. Then, the adventitious shoots developed and formed clusters, which were divided into 2-3 smaller ones every two months. The growth regulators, used at initial stage, markedly influenced subsequent shoot multiplication. Thus, the most intensive shoot formation was noted with TDZ at concentrations of 0.5-2 mg l-1 and paclobutrazol of 0.05-0.1 mg l-1.

  9. Coordination of growth in root and shoot apices by AIL/PLT transcription factors

    NARCIS (Netherlands)

    Scheres, Ben; Krizek, Beth A.

    2018-01-01

    Growth at the root tip and organ generation at the shoot tip depend on the proper functioning of apical meristems and the transitioning of meristematic cell descendants from a proliferating state to cell elongation and differentiation. Members of the AINTEGUMENTA-LIKE/PLETHORA (AIL/PLT)

  10. CPAP Tips

    Medline Plus

    Full Text Available ... Get YouTube Red. Working... Not now Try it free Find out why Close CPAP Tips from FDA ... safely and effectively use your CPAP device. Category Education License Standard YouTube License Show more Show less ...

  11. Tipping Point

    Medline Plus

    Full Text Available ... to prevent a tip-over tragedy. Share Post Facebook Twitter Google Plus Reddit Connect with Me:  Visit other Web Sites Maintained by CPSC: cpsc.gov| poolsafely.gov| recalls.gov| saferproducts.gov Privacy, Security, and Legal Notice | Accessibility Policy | Open Government @ ...

  12. CPAP Tips

    Medline Plus

    Full Text Available ... starting stop Loading... Watch Queue Queue __count__/__total__ It’s YouTube. Uninterrupted. Loading... Want music and videos with ... ads? Get YouTube Red. Working... Not now Try it free Find out why Close CPAP Tips from ...

  13. CPAP Tips

    Medline Plus

    Full Text Available ... sleeping? Here are some tips from the U.S. Food and Drug Administration (FDA) on how to safely and effectively use your CPAP device. Category ... Ambulance Service 21,588 views 4:34 Obstructive Sleep Apnea ...

  14. CPAP Tips

    Medline Plus

    Full Text Available ... sleeping? Here are some tips from the U.S. Food and Drug Administration (FDA) on how to safely ... Developers +YouTube Terms Privacy Policy & Safety Send feedback Test new features Loading... Working... Sign in to add ...

  15. Millet's Shooting Stars

    Science.gov (United States)

    Beech, M.

    1988-12-01

    In this essay two paintings by the French artist Jean-Francois Millet are described. These paintings, Les Etoiles Filantes and Nuit Etoilée are particularly interesting since they demonstrate the rare artistic employment of the shooting-star image and metaphor.

  16. Distributed trouble-shooting

    NARCIS (Netherlands)

    Post, W.M.; Bogaard, S.A.A. van den; Rasker, P.C.

    2004-01-01

    When knowledge, required for trouble-shooting at sea, can be supplied real-time but from a distance, problems, such as with the limited availability of specialists, and the high costs of maintenance, may be tackled. Unclear is, however, how this redistribution of knowledge will work in practice. We

  17. School Shootings Stun Reservation

    Science.gov (United States)

    Borja, Rhea R.; Cavanagh, Sean

    2005-01-01

    This article deals with the impact brought by the school shootings at Red Lake Indian Reservation in Minnesota to the school community. A deeply troubled 16-year-old student shot and killed seven other people and himself at a high school. The nation's deadliest school attack since the 1999 slayings at Colorado's suburban Columbine High School took…

  18. Growing Backyard Textiles

    Science.gov (United States)

    Nelson, Eleanor Hall

    1975-01-01

    For those involved in creative work with textiles, the degree of control possible in texture, finish, and color of fiber by growing and processing one's own (perhaps with students' help) can make the experience rewarding. The author describes the processes for flax and nettles and gives tips on necessary equipment. (Author/AJ)

  19. Radiocesium distribution in bamboo shoots after the Fukushima nuclear accident.

    Directory of Open Access Journals (Sweden)

    Takumi Higaki

    Full Text Available The distribution of radiocesium was examined in bamboo shoots, Phyllostachys pubescens, collected from 10 sites located some 41 to 1140 km from the Fukushima Daiichi nuclear power plant, Japan, in the Spring of 2012, 1 year after the Fukushima nuclear accident. Maximum activity concentrations for radiocesium ¹³⁴Cs and ¹³⁷Cs in the edible bamboo shoot parts, 41 km away from the Fukushima Daiichi plant, were in excess of 15.3 and 21.8 kBq/kg (dry weight basis; 1.34 and 1.92 kBq/kg, fresh weight, respectively. In the radiocesium-contaminated samples, the radiocesium activities were higher in the inner tip parts, including the upper edible parts and the apical culm sheath, than in the hardened culm sheath and underground basal parts. The radiocesium/potassium ratios also tended to be higher in the inner tip parts. The radiocesium activities increased with bamboo shoot length in another bamboo species, Phyllostachys bambusoides, suggesting that radiocesium accumulated in the inner tip parts during growth of the shoots.

  20. The Binomial Distribution in Shooting

    Science.gov (United States)

    Chalikias, Miltiadis S.

    2009-01-01

    The binomial distribution is used to predict the winner of the 49th International Shooting Sport Federation World Championship in double trap shooting held in 2006 in Zagreb, Croatia. The outcome of the competition was definitely unexpected.

  1. Grow, Baby, Grow

    Science.gov (United States)

    Maybe you quit smoking during your pregnancy. Or maybe you struggled and weren’t able to stay quit. Now that your baby is here, trying to stay away from smoking is still important. That’s because the chemicals in smoke can make it harder for your baby to grow like he or she should.

  2. Tip enhancement

    CERN Document Server

    Kawata, Satoshi

    2007-01-01

    This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field.·Near-field Raman scattering·Tip-enhanced Raman spectroscopy·Surface-enhanced Raman spectroscopy·Nano-photonics·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits·Single molecule detection

  3. Micropropagation of Banana Varieties (Musa spp.) Using Shoot-Tip ...

    African Journals Online (AJOL)

    propagation method appears to be unable to supply the increasing demand for ... Explant Preparation and Surface Sterilization. Explants were excised ... of the medium was adjusted to 5.7 using NaOH or HCl (0.1 or 1N) before autoclaving.

  4. An effective disinfection protocol for plant regeneration from shoot tip ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... 2National Agriculture and Animal Resources Research Center, Ministry of Agriculture, Kingdom of Saudi ... If we can obtain explant materials from offshoot, ... 2 – 3 mm were again surface sterilized in sodium hypochlorite.

  5. Efficient regeneration of plants from shoot tip explants of ...

    African Journals Online (AJOL)

    samrat1765

    2013-03-20

    Mar 20, 2013 ... dish containing sterile filter paper and cut longitudinally with the help of sterile surgical blade to expose the tiny seeds. Seeds were scooped out by sterile spatula and spread over the surface of MS medium alone and supplemented with different combination and concentration of BAP and NAA.

  6. Clonal propagation of Stevia rebaudiana Bertoni by stem-tip culture.

    Science.gov (United States)

    Tamura, Y; Nakamura, S; Fukui, H; Tabata, M

    1984-10-01

    Clonal propagation of Stevia rebaudiana has been established by culturing stem-tips with a few leaf primordia on an agar medium supplemented with a high concentration (10 mg/l) of kinetin. Anatomical examination has suggested that these multiple shoots originate from a number of adventitious buds formed on the margin of the leaf. Innumerable shoots can be obtained by repeating the cycle of multiple-shoot formation from a single stem-tip of Stevia. These shoots produce roots when transferred to a medium containing NAA (0.1 mg/l) without kinetin. The regenerated plantlets can be transplanted to soil.

  7. Radiographing roots and shoots

    International Nuclear Information System (INIS)

    Shariffah Noor Khamseah Al Idid

    1985-01-01

    The effect of seed orientation on germination time and on shoot and root growth patterns is studied. Neutron radiography is used to observe the development of 4 types of plants, maize, greenpea, soya bean and padi. These plants were grown in varying orientations; sand sizes, sand thicknesses, and level of water content. Radiography of the seeds and plants were obtained for time exposure ranging from 3-12 hours and at reactor thermal power level, ranging from 500-750 kilowatts. Results obtained showed that seeds planted in varying orientations need different length of time for shoot emergence. Neutron radiography is now developed to other areas of non-industrial applications in Malaysia. (A.J.)

  8. Ship and Shoot

    Science.gov (United States)

    Woods, Ron

    2012-01-01

    Ron Woods shared incredibly valuable insights gained during his 28 years at the Kennedy Space Center (KSC) packaging Flight Crew Equipment for shuttle and ISS missions. In particular, Woods shared anecdotes and photos from various processing events. The moral of these stories and the main focus of this discussion were the additional processing efforts and effects related to a "ship-and-shoot" philosophy toward flight hardware.

  9. School Shootings and Student Performance

    OpenAIRE

    Panu Poutvaara; Olli Ropponen

    2010-01-01

    In this paper, we study how high school students reacted to the shocking news of a school shooting. The shooting coincided with national high-school matriculation exams. As there were exams both before and after the shooting, we can use a difference-in-differences analysis to uncover how the school shooting affected the test scores compared to previous years. We find that the average performance of young men declined due to the school shooting, whereas we do not observe a similar pattern for ...

  10. Differences in proleptic and epicormic shoot structures in relation to water deficit and growth rate in almond trees (Prunus dulcis).

    Science.gov (United States)

    Negrón, Claudia; Contador, Loreto; Lampinen, Bruce D; Metcalf, Samuel G; Guédon, Yann; Costes, Evelyne; DeJong, Theodore M

    2014-02-01

    Shoot characteristics differ depending on the meristem tissue that they originate from and environmental conditions during their development. This study focused on the effects of plant water status on axillary meristem fate and flowering patterns along proleptic and epicormic shoots, as well as on shoot growth rates on 'Nonpareil' almond trees (Prunus dulcis). The aims were (1) to characterize the structural differences between proleptic and epicormic shoots, (2) to determine whether water deficits modify shoot structures differently depending on shoot type, and (3) to determine whether shoot structures are related to shoot growth rates. A hidden semi-Markov model of the axillary meristem fate and number of flower buds per node was built for two shoot types growing on trees exposed to three plant water status treatments. The models segmented observed shoots into successive homogeneous zones, which were compared between treatments. Shoot growth rates were calculated from shoot extension measurements made during the growing season. Proleptic shoots had seven successive homogeneous zones while epicormic shoots had five zones. Shoot structures were associated with changes in growth rate over the season. Water deficit (1) affected the occurrence and lengths of the first zones of proleptic shoots, but only the occurrence of the third zone was reduced in epicormic shoots; (2) had a minor effect on zone flowering patterns and did not modify shoot or zone composition of axillary meristem fates; and (3) reduced growth rates, although patterns over the season were similar among treatments. Two meristem types, with different latency durations, produced shoots with different growth rates and distinct structures. Differences between shoot type structure responses to water deficit appeared to reflect their ontogenetic characteristics and/or resource availability for their development. Tree water deficit appeared to stimulate a more rapid progression through ontogenetic states.

  11. Effect of multiple subcultures on Musa shoots derived from cassava ...

    African Journals Online (AJOL)

    Shoot tip explants excised from in vitro plantlets of two Musa genotypes (TM3X 15108-6 and TMBX 612-74) were seeded singly into test tubes containing twenty milliliters each of Musa multiplication medium gelled differently in 60 and 70 gL-l cassava starch as well as 5 gL-l agar and placed on shelves under 14 h photo ...

  12. Recent advances in the cryopreservation of shoot-derived germplasm of economically important fruit trees of Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis.

    Science.gov (United States)

    Benelli, Carla; De Carlo, Anna; Engelmann, Florent

    2013-01-01

    This paper presents the advances made over the last decade in cryopreservation of economically important vegetatively propagated fruit trees. Cryopreservation protocols have been established using both dormant buds sampled on field-grown plants and shoot tips sampled on in vitro plantlets. In the case of dormant buds, scions are partially dehydrated by storage at -5 °C, and then cooled slowly to -30 °C using low cooling rates (c.a. 1 °C/h) before immersion in liquid nitrogen. After slow rewarming and rehydration of samples, regrowth takes place either through grafting of buds on rootstocks or excision of apices and inoculation in vitro. In the case of shoot tips of in vitro plantlets, the cryopreservation techniques employed are the following: controlled rate cooling procedures involving slow prefreezing followed by immersion in liquid nitrogen or vitrification-based procedures including encapsulation-dehydration, vitrification, encapsulation-vitrification and droplet-vitrification. The current status of cryopreservation for a series of fruit tree species including Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis is presented. Routine application of cryopreservation for long-term germplasm storage in genebanks is currently limited to apple and pear, for which large cryopreserved collections have been established at NCGRP, Fort Collins (USA), using dormant buds and in vitro shoot tips, respectively. However, there are a growing number of examples of pilot scale testing experiments under way for different species in various countries. Progress in the further development and application of cryopreservation techniques will be made through a better understanding of the mechanisms involved in the induction of tolerance to dehydration and cryopreservation in frozen explants. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana

    OpenAIRE

    Wahl, Vanessa; Brand, Luise H; Guo, Ya-Long; Schmid, Markus

    2010-01-01

    Abstract Background Throughout their lives plants produce new organs from groups of pluripotent cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS) and the CLAVATA (CLV) proteins. This regulatory circuit is further fine-tuned by morphogenic signals such as hormones and sugars. Results Here we show that a family of four plant-specific pro...

  14. A School Shooting Plot Foiled

    Science.gov (United States)

    Swezey, James A.; Thorp, Kimberly A.

    2010-01-01

    Dinkes, Cataldi, and Lin-Kelly (2007) claims that 78% of public schools reported one or more violent incidents during the 2005/2006 school year. School shootings are a rare but real threat on school campuses. Shootings at private schools are even less frequent with only a few recorded examples in the United States. This case study examines how a…

  15. The effect of triacontanol on shoot multiplication and production of antioxidant compounds in shoot cultures of Salvia officinalis L.

    Directory of Open Access Journals (Sweden)

    Izabela Grzegorczyk

    2011-01-01

    Full Text Available This report describes the effect of triacontanol on shoot multiplication and production of antioxidant compounds (carnosic acid, carnosol and rosmarinic acid in S. officinalis cultures grown on MS basal medium (agar solidified medium supplemented with 0.1 mg l-1 IAA, 0.45 mg l-1 BAP. It was found that shoot proliferation significantly increased when triacontanol at concentrations of 5, 10 or 20 µg l-1 was added to the medium. HPLC analysis of acetone and methanolic extracts of sage shoots showed that the production of diterpenoids, carnosic acid/carnosol ratio, as well as, contents of rosmarinic acid were also affected by the treatment with triacontanol. The highest stimulation effect of triacontanol was observed on the production of carnosol, where the treatment with 20 µg l l-1 increased the content of this diterpenoid 4.5-fold compared to that in the control (sage shoots growing on MS basal medium, only.

  16. Structure–Function Relationships in Highly Modified Shoots of Cactaceae

    Science.gov (United States)

    MAUSETH, JAMES D.

    2006-01-01

    • Background and Aims Cacti are extremely diverse structurally and ecologically, and so modified as to be intimidating to many biologists. Yet all have the same organization as most dicots, none differs fundamentally from Arabidopsis or other model plants. This review explains cactus shoot structure, discusses relationships between structure, ecology, development and evolution, and indicates areas where research on cacti is necessary to test general theories of morphogenesis. • Scope Cactus leaves are diverse; all cacti have foliage leaves; many intermediate stages in evolutionary reduction of leaves are still present; floral shoots often have large, complex leaves whereas vegetative shoots have microscopic leaves. Spines are modified bud scales, some secrete sugar as extra-floral nectaries. Many cacti have juvenile/adult phases in which the flowering adult phase (a cephalium) differs greatly from the juvenile; in some, one side of a shoot becomes adult, all other sides continue to grow as the juvenile phase. Flowers are inverted: the exterior of a cactus ‘flower’ is a hollow vegetative shoot with internodes, nodes, leaves and spines, whereas floral organs occur inside, with petals physically above stamens. Many cacti have cortical bundles vascularizing the cortex, however broad it evolves to be, thus keeping surface tissues alive. Great width results in great weight of weak parenchymatous shoots, correlated with reduced branching. Reduced numbers of shoot apices is compensated by great increases in number of meristematic cells within individual SAMs. Ribs and tubercles allow shoots to swell without tearing during wet seasons. Shoot epidermis and cortex cells live and function for decades then convert to cork cambium. Many modifications permit water storage within cactus wood itself, adjacent to vessels. PMID:16820405

  17. Structure-function relationships in highly modified shoots of cactaceae.

    Science.gov (United States)

    Mauseth, James D

    2006-11-01

    Cacti are extremely diverse structurally and ecologically, and so modified as to be intimidating to many biologists. Yet all have the same organization as most dicots, none differs fundamentally from Arabidopsis or other model plants. This review explains cactus shoot structure, discusses relationships between structure, ecology, development and evolution, and indicates areas where research on cacti is necessary to test general theories of morphogenesis. Cactus leaves are diverse; all cacti have foliage leaves; many intermediate stages in evolutionary reduction of leaves are still present; floral shoots often have large, complex leaves whereas vegetative shoots have microscopic leaves. Spines are modified bud scales, some secrete sugar as extra-floral nectaries. Many cacti have juvenile/adult phases in which the flowering adult phase (a cephalium) differs greatly from the juvenile; in some, one side of a shoot becomes adult, all other sides continue to grow as the juvenile phase. Flowers are inverted: the exterior of a cactus 'flower' is a hollow vegetative shoot with internodes, nodes, leaves and spines, whereas floral organs occur inside, with petals physically above stamens. Many cacti have cortical bundles vascularizing the cortex, however broad it evolves to be, thus keeping surface tissues alive. Great width results in great weight of weak parenchymatous shoots, correlated with reduced branching. Reduced numbers of shoot apices is compensated by great increases in number of meristematic cells within individual SAMs. Ribs and tubercles allow shoots to swell without tearing during wet seasons. Shoot epidermis and cortex cells live and function for decades then convert to cork cambium. Many modifications permit water storage within cactus wood itself, adjacent to vessels.

  18. Effect Of Gamma Rays And Growth Regulators On Explants Excised From In Vitro Shoots And Greenhouse Seedlings, Of Pepper (Capsicum Annum L.)

    International Nuclear Information System (INIS)

    Maarouf, A. A.; Kassem, M.

    2004-01-01

    This experiment was conducted on pepper (Capsicum annum L.) to compare the ability of the in vitro explants with those of greenhouse grown seedlings on shoot proliferation and callus formation and their ability to form plantlets and the effect of gamma irradiation and growth regulators on the shoot tip, hypocotyls and leaf tissue was used as laboratory explants, leaf tissue nodes and internodes were taken from greenhouse seedlings. 6- benzyla-minopurine (BAP) in different concentrations was combined with Indoleacertic acid (IAA) to know their effect on shoot proliferation, 2,4 - Dichlorophenoxy acetic acid (2,4- D) was used for callus formation, and use stimulation effect of gamma irradiation, potassium nitrat (KNO 3 ), Thidaiazurom (TDZ) and casine hydrolysate (CH) for plantlet formation. The results showed that the highest percentage of callus was obtained by in vitro hypocotyls and greenhouse grown nodes followed by in vitro leaf tissue thereafter greenhouse leaf tissue. The shoot tips were the lowest efficient explants in producing callus in both in vitro and greenhouse ones. The highest percentage of shooting resulted from shoot tip, hypocotyls and leaf tissue of in vitro explants, followed by shoot tip, nodes and internodes of greenhouse grown explants and the lowest percentage was recorded by leaf tissue. Highest percentage of shoot number was obtained form greenhouse grown shoot tip followed by in vitro shoot tip, hypocotyls and leaf tissue of greenhouse grown seedlings the internodes were the lowest efficient in producing shoots. The highest success in plantlet formation was caused by TDZ followed by gamma irradiation and the other treatments were equaled. (Authors)

  19. Chlordecone Transfer and Distribution in Maize Shoots.

    Science.gov (United States)

    Pascal-Lorber, Sophie; Létondor, Clarisse; Liber, Yohan; Jamin, Emilien L; Laurent, François

    2016-01-20

    Chlordecone (CLD) is a persistent organic pollutant (POP) that was mainly used as an insecticide against banana weevils in the French West Indies (1972-1993). Transfer of CLD via the food chain is now the major mechanism for exposure of the population to CLD. The uptake and the transfer of CLD were investigated in shoots of maize, a C4 model plant growing under tropical climates, to estimate the exposure of livestock via feed. Maize plants were grown on soils contaminated with [(14)C]CLD under controlled conditions. The greatest part of the radioactivity was associated with roots, nearly 95%, but CLD was detected in whole shoots, concentrations in old leaves being higher than those in young ones. CLD was thus transferred from the base toward the plant top, forming an acropetal gradient of contaminant. In contrast, results evidenced the existence of a basipetal gradient of CLD concentration within leaves whose extremities accumulated larger amounts of CLD because of evapotranspiration localization. Extractable residues accounted for two-thirds of total residues both in roots and in shoots. This study highlighted the fact that the distribution of CLD contamination within grasses resulted from a conjunction between the age and evapotranspiration rate of tissues. CLD accumulation in fodder may be the main route of exposure for livestock.

  20. Mechanisms of waterlogging tolerance in wheat - a review of root and shoot physiology

    DEFF Research Database (Denmark)

    Herzog, Max; Striker, Gustavo G; Colmer, Timothy D

    2016-01-01

    :shoot ratio. Genotypes differ in seminal root anoxia tolerance, but mechanisms remain to be established; ethanol production rates do not explain anoxia tolerance. Root tip survival is short-term, and thereafter, seminal root re-growth upon re-aeration is limited. Genotypes differ in adventitious root numbers....... Although photosynthesis declines, sugars typically accumulate in shoots of waterlogged plants. Mn or Fe toxicity might occur in shoots of wheat on strongly acidic soils, but probably not more widely. Future breeding for waterlogging tolerance should focus on root internal aeration and better N...

  1. Distribution of radiocesium in bamboo leaves, roots and shoots. Application of an imaging plate

    International Nuclear Information System (INIS)

    Minowa, Haruka; Ogata, Yoshimune; Satou, Yukihiko

    2012-01-01

    When radiocesium is taken into a wild plant accidentally, it will circulate for a certain period of time. Bamboo is that in some cases relative high concentration of radiocesium have been reported. Radiocesium is considered to be concentrated in bamboo shoot by translocation in plants from bamboo leaves or roots. In this study, to investigate the behavior of radiocesium, shoots, roots, branches and leaves of bamboo (Phyllostadhys edulis) were collected at Yamakiya area, Kawamata-machi, Date-gun, Fukushima Prefecture. Radiation image analysis was conducted using an imaging plate BAS 2040 (Fujifilm) and an image analyzer Typhoon FLA7000 (GE Healthcare Japan Corp.). The content of radiocesium was about 500 Bq for "1"3"4Cs and 700 Bq for "1"3"7Cs per the bamboo shoot (500 g approximately). In the edible parts of bamboo shoots, the skin of bamboo shoots and leaves of newly-grown, radiocesium uptake was in high concentration, especially at the tip. (author)

  2. Micropropagation of Vaccinium sp. by in vitro axillary shoot proliferation.

    Science.gov (United States)

    Litwińczuk, Wojciech

    2013-01-01

    The Vaccinium genus contains several valuable fruit and ornamental species, among others: highbush blueberry (Vaccinium × corymbosum L.), cranberry (Vaccinium macrocarpon Ait.), and lingonberry (Vaccinium vitis-idaea L.). In some most popular and valuable cultivars, the conventional propagation methods, exploiting hard or soft wood cuttings, are inefficient. The demand for nursery plants could be fulfilled only by micropropagation. In principle cultivars are propagated in vitro through similar three-stage method, based on subculture of shoot explants on different culture media supplemented with IAA (0-4 mg/L) and 2iP (5-10 mg/L), and rooting shoots in vivo. The obtained plantlets are transferred to peat substrate and grown in the glasshouse until the end of growing period. The development of adventitious shoots should be monitored and controlled during in vitro stages. Many clones have specific requirements for growing conditions and/or are recalcitrant.

  3. Determination of sink intensity of side shoots by the use of radioactive substances

    International Nuclear Information System (INIS)

    Hartmann, H.D.; Forche, E.

    1980-01-01

    The influence of side shoots in the source-sink system of tomato plants was demonstrated by following the translocation of 32 P and 14 C applied to different leaves. The results showed that the side shoots were important sinks for photosynthetic products until the growing fruits of adjoining inflorescences became predominant attraction centres. (orig.) [de

  4. High efficiency indirect shoot regeneration and hypericin content in ...

    African Journals Online (AJOL)

    USER

    2010-04-12

    Apr 12, 2010 ... opium poppy. Support of hormone-free medium on shoot regeneration from callus has also been underlined for sugarbeet (Doley and Saunders, 1989). In our study, obtained regenerants acclimatized readily, alived (94%) and are still continuing to grow in the greenhouse of our department. Cell or callus ...

  5. Micropropagation of Asparagus by in vitro shoot culture.

    Science.gov (United States)

    Stajner, Nataša

    2013-01-01

    Asparagus officinalis is most extensively studied species within the genus Asparagus, which is well known as garden asparagus. This species is dioecious with unisexual flowers, which means that generative propagation gives roughly equal number of male and female plants. Male plants are high yielders and preferred commercially over female plants. Tissue culture techniques could efficiently promote vegetative propagation of male plants and pave the way for efficient plant breeding.This chapter describes an efficient micropropagation protocol for developing rapid growing in vitro Asparagus shoot cultures. The source of explants, inoculation, and shoot proliferation, followed by shoot propagation, rooting, and acclimatization is described. The optimal medium for Asparagus micropropagation described in this chapter is composed of MS macro- and microelements and a combination of auxins and cytokinins. Plant growth regulators NAA, kinetin, and BA were used in various concentrations. Three different media representing the whole micropropagation protocol of Asparagus are described; medium for shoot initiation, medium for shoot multiplication, and medium for root formation. By in vitro propagation of Asparagus, root initiation is difficult, but can be promoted by adding growth retardant ancymidol which also greatly promotes shoot development and suppresses callus formation.

  6. In vitro regeneration of Salix nigra from adventitious shoots.

    Science.gov (United States)

    Lyyra, Satu; Lima, Amparo; Merkle, Scott A

    2006-07-01

    Black willow (Salix nigra Marsh.) is the largest and only commercially important willow species in North America. It is a candidate for phytoremediation of polluted soils because it is fast-growing and thrives on floodplains throughout eastern USA. Our objective was to develop a protocol for the in vitro regeneration of black willow plants that could serve as target material for gene transformation. Unexpanded inflorescence explants were excised from dormant buds collected from three source trees and cultured on woody plant medium (WPM) supplemented with one of: (1) 0.1 mg l(-1) thidiazuron (TDZ); (2) 0.5 mg l(-1) 6-benzoaminopurine (BAP); or (3) 1 mg l(-1) BAP. All plant growth regulator (PGR) treatments induced direct adventitious bud formation from the genotypes. The percentage of explants producing buds ranged from 20 to 92%, depending on genotype and treatment. Although most of the TDZ-treated inflorescences produced buds, these buds failed to elongate into shoots. Buds on explants treated with BAP elongated into shoots that were easily rooted in vitro and further established in potting mix in high humidity. The PGR treatments significantly affected shoot regeneration frequency (P < 0.01). The highest shoot regeneration frequency (36%) was achieved with Genotype 3 cultured on 0.5 mg l(-1) BAP. Mean number of shoots per explant varied from one to five. The ability of black willow inflorescences to produce adventitious shoots makes them potential targets for Agrobacterium-mediated transformation with heavy-metal-resistant genes for phytoremediation.

  7. Characteristics of schools in which fatal shootings occur.

    Science.gov (United States)

    de Apodaca, Roberto Flores; Brighton, Lauren M; Perkins, Ashley N; Jackson, Kiana N; Steege, Jessica R

    2012-04-01

    School-based violence, and fatal school shootings in particular, have gained increased attention in the media and psychological literature. Most reports have focused on the characteristics of perpetrators, but there is a growing awareness that school-related factors may also influence the occurrence of fatal school shootings. The current study examined several key characteristics of all schools where random (38) and targeted (96) fatal shootings occurred in the United States between 1966 and 2009. These were compared with a group (138) of schools randomly selected to represent the population of all schools in the United States. The size of a school's enrollment, urban or suburban locale, public funding, and predominantly non-white enrollment were positively associated with fatal shootings. Universities and colleges were disproportionately associated with random shootings and high schools with targeted ones. It was proposed that characteristics of schools that allow feelings of anonymity or alienation among students may help create environmental conditions associated with fatal school shootings. Implications for future research and interventions are considered.

  8. Tips on Blood Testing

    Science.gov (United States)

    ... Test Pain, Discomfort and Anxiety Tips to Help Children through Their Medical Tests Tips to Help the Elderly through Their Medical Tests Find Us On Social Media: Facebook Twitter Google Plus Footer Menu Home About ...

  9. The TIPS Liquidity Premium

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller; Christensen, Jens H.E.; Simon Riddell, Simon

    We introduce an arbitrage-free term structure model of nominal and real yields that accounts for liquidity risk in Treasury inflation-protected securities (TIPS). The novel feature of our model is to identify liquidity risk from individual TIPS prices by accounting for the tendency that TIPS, lik...

  10. Tip studies using CFD and comparison with tip loss models

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Johansen, J.

    2004-01-01

    The flow past a rotating LM8.2 blade equipped with two different tips are computed using CFD. The different tip flows are analysed and a comparison with two different tip loss models is made. Keywords: tip flow, aerodynamics, CFD......The flow past a rotating LM8.2 blade equipped with two different tips are computed using CFD. The different tip flows are analysed and a comparison with two different tip loss models is made. Keywords: tip flow, aerodynamics, CFD...

  11. PERBANDINGAN JUMP SHOOT DENGAN AWALAN DAN TANPA AWALAN TERHADAP PENINGKATAN KETEPATAN SHOOTING DALAM PERMAINAN BOLABASKET

    OpenAIRE

    I Gusti Ngurah Agung Cahya Prananta; N. Adiputra; I P G Adiatmika

    2015-01-01

    The effectiveness of  jump-shoot technique step jump shoot and still jump shoot in a game is still questionable,  because many different assumptions arise. One opinion stated that step jump shoot was more effective and the other stated that and still jump shoot was more efective. Therefore it is necessary to do research on the analysis of the results of step jump shoot and and still jump shoot to improve the accuracy of shooting in a basketball. The experimental research had been conducted on...

  12. Fruit production and branching density affect shoot and whole-tree wood to leaf biomass ratio in olive.

    Science.gov (United States)

    Rosati, Adolfo; Paoletti, Andrea; Al Hariri, Raeed; Famiani, Franco

    2018-02-14

    The amount of shoot stem (i.e., woody part of the shoot) dry matter per unit shoot leaf dry matter (i.e., the shoot wood to leaf biomass ratio) has been reported to be lower in short shoots than in long ones, and this is related to the greater and earlier ability of short shoots to export carbon. This is important in fruit trees, since the greater and earlier carbon export ability of shoots with a lower wood to leaf biomass ratio improves fruit production. This ratio may vary with cultivars, training systems or plant age, but no study has previously investigated the possible effect of fruit production. In this study on two olive cultivars (i.e., Arbequina, with low growth rate, and Frantoio, with high growth rate) subject to different fruit production treatments, we found that at increasing fruit production, shoot length and shoot wood to leaf biomass ratio were proportionally reduced in the new shoots growing at the same time as the fruit. Specifically, fruit production proportionally reduced total new-shoot biomass, length, leaf area and average shoot length. With decreasing shoot length, shoot diameter, stem mass, internode length, individual leaf area and shoot wood to leaf biomass ratio also decreased. This may be viewed as a plant strategy to better support fruit growth in the current year, given the greater and earlier ability of short shoots to export carbon. Moreover, at the whole-tree level, the percentage of total tree biomass production invested in leaves was closely correlated with branching density, which differed significantly across cultivars. By branching more, Arbequina concentrates more shoots (thus leaves) per unit of wood (trunk, branches and root) mass, decreasing wood to leaf biomass ratio at the whole-tree level. Therefore, while, at the shoot level, shoot length determines shoot wood to leaf biomass ratio, at the canopy level branching density is also an important determinant of whole-tree wood to leaf biomass ratio. Whole-tree wood to leaf

  13. Shootings Revive Debates on Security

    Science.gov (United States)

    Shah, Nirvi

    2013-01-01

    By nearly all accounts, the staff and students at Sandy Hook Elementary School did everything right on Dec. 14--and with the security measures they took before that day--when a young man armed with powerful weapons blasted his way into the school. But the deadliest K-12 school shooting in American history, a day that President Barack Obama has…

  14. School Shootings as Organizational Deviance.

    Science.gov (United States)

    Fox, Cybelle; Harding, David J.

    2005-01-01

    This article argues that rampage school shootings in American public schools can be understood as instances of organizational deviance, which occurs when events created by or in organizations do not conform to an organization's goals or expectations and produce unanticipated and harmful outcomes. Drawing on data from qualitative case studies of…

  15. School Shootings in Policy Spotlight

    Science.gov (United States)

    Maxwell, Lesli A.

    2006-01-01

    The three school shootings that left a principal and six students dead in less than a week have sparked a barrage of pledges from national and state political leaders to tighten campus security. School safety experts urged caution against overreacting to the horrific, but rare, incidents in rural schools in Colorado, Pennsylvania, and Wisconsin.…

  16. School Shootings and Critical Pedagogy

    Science.gov (United States)

    Schiller, Juliet

    2013-01-01

    What has been left out of studying school violence and shootings is a comprehensive look at the culture that creates violence and the lack of support for those deemed "different" in an educational setting that promotes and rewards competition. If parents, teachers, and other adults associated with children were teaching the values of…

  17. Shooting the Moon

    Science.gov (United States)

    Andrews, Daniel R.

    2011-01-01

    labor and hardware which is attempting to assure nothing will go wrong. Sophisticated designs, with doubly- or triply-redundant systems, extensive testing to verify those systems, and numerous engineering test units built to learn and evolve a hardware design, all drive the cost and time required to implement. Human spaceflight is an expensive business because of the exceptional system complexity and levels of assurance required for human space travel. What about missions that do not involve human spaceflight? What about missions whose potential failure will not take a human life, whose costs are small and whose urgency and importance are limited by design? A portfolio consisting of this type of mission can be designed to be risk tolerant, not requiring large expenditures to guarantee against failure. With the money saved, the number of missions that can be executed within the portfolio grows, or the total cost of the portfolio can be reduced. The NASA LCROSS mission is a pathfinder example of a low-cost, quick turn-around mission which struck a balance on mission risk, while accomplishing big objectives, like defining how we understand the Moon.

  18. Training visual control in wheelchair basketball shooting

    NARCIS (Netherlands)

    Oudejans, R.R.D.; Heubers, S.; Ruitenbeek, J-R.J.A.C.; Janssen, T.W.J.

    2012-01-01

    We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use

  19. Training Visual Control in Wheelchair Basketball Shooting

    Science.gov (United States)

    Oudejans, Raoul R. D.; Heubers, Sjoerd; Ruitenbeek, Jean-Rene J. A. C.; Janssen, Thomas W. J.

    2012-01-01

    We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use target information as late as possible.…

  20. Continuum damage mechanics analysis of crack tip zone

    International Nuclear Information System (INIS)

    Yinchu, L.; Jianping, Z.

    1989-01-01

    The crack tip field and its intensity factor play an important role in fracture mechanics. Generally, the damage such as microcracks, microvoids etc. will initiate and grow in materials as the cracked body is subjected to external loadings, especially in the crack tip zone. The damage evolution will load to the crack tip damage field and the change of the stress, strain and displacement fields of cracks tip zone. In this paper, on the basis of continuum damage mechanics, the authors have derived the equations which the crack tip field and its intensity factor must satisfy in a loading process, calculated the angle distribution curves of stress, strain and displacement fields in a crack tip zone and have compared them with the corresponding curves of HRR field and linear elastic field in undamaged materials. The equations of crack tip field intensity factors have been solved and its solutions give the variation of the field intensity factors with the loading parameter

  1. Risk factors in school shootings.

    Science.gov (United States)

    Verlinden, S; Hersen, M; Thomas, J

    2000-01-01

    Nine incidents of multiple-victim homicide in American secondary schools are examined and common risk factors are identified. The literature dealing with individual, family, social, societal, and situational risk factors for youth violence and aggression is reviewed along with existing risk assessment methods. Checklists of risk factors for serious youth violence and school violence are used in reviewing each school shooting case. Commonalties among the cases and implications for psychologists practicing in clinical and school settings are discussed.

  2. The age of school shootings: a sociological interpretation on masculinity

    Directory of Open Access Journals (Sweden)

    Celis, Jorge

    2015-01-01

    Full Text Available Over the past two decades there has been a growing interest in the study of the horrendous massacres perpetrated by students at school premises. These massacres, known as school shootings, haven been predominantly analyzed by employing psychological approaches. Despite the fact that empirical research clearly reveals that school shooters tend not to present life-long histories of mental illness, these approaches usually put a strong emphasis on the perpetrator’s individual pathologies, ignoring the influence that social values such as masculinity exert on perpetrators’ actions. Consequently, perpetrators are viewed as lone wolf shooters and school shootings as isolated cases. Based on data derived from scholarly works published mainly in peer-review journals and the sociological theory of P. Berger and T. Luckmann, the aim of this essay is to offer a sociological interpretation on school shootings by explaining why school shooters commit violent actions against teachers and classmates as a form of retrieving their masculinity. In this regard, the essay finds that male rather than female students commit school shootings. At the same time, the majority of perpetrators have had parents who were gun collectors. It is no coincide that shooters mostly use family guns to commit the massacres. Additionally, shooters see school as a social entity that has diminished their masculinity, and the way to reaffirm their masculinity is to attack randomly students and teachers in full view of the rest of school members during school hours.

  3. ADHD: Tips to Try

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español ADHD: Tips to Try KidsHealth / For Teens / ADHD: Tips to Try Print en español TDAH: Consejos que puedes probar ADHD , short for attention deficit hyperactivity disorder , is a ...

  4. Total Telephone Tips.

    Science.gov (United States)

    Corder, Lloyd E.; And Others

    This manual of telephone behavior tips for business and sales professionals offers ways to handle the disgruntled caller and makes suggestions on topics relevant to the telephone. The manual is divided into the following sections and subsections: (1) Common Courtesy (staff tips, answering the telephone, screening calls, transferring calls, taking…

  5. Safety Tips: Basketball (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Safety Tips: Basketball KidsHealth / For Parents / Safety Tips: Basketball ... make sure they follow these tips. Why Basketball Safety Is Important Fortunately, very few basketball injuries are ...

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... the liver). Portal hypertension can also occur in children, although children are much less likely to require a TIPS. ... intentionally to solve the problem. Although extremely rare, children may also require a TIPS procedure. TIPS in ...

  7. Effect of light on contents of coumarin compounds in shoots of Ruta graveolens L. cultivated in vitro

    Directory of Open Access Journals (Sweden)

    Halina Ekiert

    2014-01-01

    Full Text Available Shoots of Ruta graveolens L. (Rutaceae were cultivated in stationary liquid culture under different light conditions: constant artificial light (900 lx, darkness, constant artificial light (900 ix following irradiation with UV-C light. The contents of five furanocoumarins: psoralen, bergapten, xanthotoxin, isopimpinellin and imperatorin, as well as biogenetic precursor of these metabolites, umbelliferone, were determined by HPLC method in shoots cultivated in vitro and in overground parts of plants growing in open air. It was shown that light conditions, tested in these experiments, significantly influenced contents of the metabolites in shoots cultivated in in vitro culture. Total content of the coumarin compounds in shoots cultivated under constant artificial light (900 lx was equal or higher than in plants growing under natural conditions. Therefore, it is suggested that stationary liquid shoot culture of R. graveolens. can be an alternative source for obtaining biologically active furanocoumarins.

  8. Growing bubbles and freezing drops: depletion effects and tip singularities

    NARCIS (Netherlands)

    Enriquez Paz y Puente, O.R.

    2015-01-01

    In this thesis, the author investigates the growth of gas bubbles in a supersaturated solution and the freezing of water drops when placed on a cold plate. Supersaturated solutions are common in nature and industry; perhaps the best know examples are carbonated drinks, such as beer or soda. These

  9. [School shooting in statu nascendi].

    Science.gov (United States)

    Knecht, Thomas

    2012-01-01

    In the last few years, amok-like killings and especially so-called "school shootings" have received a great deal of public attention both in the Old and the New world. Meanwhile, criminal psychological research has gained a thorough insight into this dangerous development in young people. Thus, the possibility to assess the concrete threat of such a multiple killing before it is carried out has been considerably improved, as many prognostic criteria have been worked out in the meantime. The case report presented shows that it is possible to exercise a favourable influence on this critical negative trend.

  10. Three ancient hormonal cues co-ordinate shoot branching in a moss.

    Science.gov (United States)

    Coudert, Yoan; Palubicki, Wojtek; Ljung, Karin; Novak, Ondrej; Leyser, Ottoline; Harrison, C Jill

    2015-03-25

    Shoot branching is a primary contributor to plant architecture, evolving independently in flowering plant sporophytes and moss gametophytes. Mechanistic understanding of branching is largely limited to flowering plants such as Arabidopsis, which have a recent evolutionary origin. We show that in gametophytic shoots of Physcomitrella, lateral branches arise by re-specification of epidermal cells into branch initials. A simple model co-ordinating the activity of leafy shoot tips can account for branching patterns, and three known and ancient hormonal regulators of sporophytic branching interact to generate the branching pattern- auxin, cytokinin and strigolactone. The mode of auxin transport required in branch patterning is a key divergence point from known sporophytic pathways. Although PIN-mediated basipetal auxin transport regulates branching patterns in flowering plants, this is not so in Physcomitrella, where bi-directional transport is required to generate realistic branching patterns. Experiments with callose synthesis inhibitors suggest plasmodesmal connectivity as a potential mechanism for transport.

  11. Lightning Safety Tips and Resources

    Science.gov (United States)

    ... Services Careers Contact Us Glossary Safety National Program Lightning Safety Tips and Resources Weather.gov > Safety > Lightning Safety Tips and Resources Lightning Resources Lightning strikes ...

  12. Effects of plastic anisotropy on crack-tip behaviour

    DEFF Research Database (Denmark)

    Legarth, Brian Nyvang; Tvergaard, Viggo; Kuroda, Mitsutoshi

    2002-01-01

    For a crack in a homogeneous material the effect of plastic anisotropy on crack-tip blunting and on the near-tip stress and strain fields is analyzed numerically. The full finite strain analyses are carried out for plane strain under small scale yielding conditions, with purely symmetric mode I...... loading remote from the crack-tip. In cases where the principal axes of the anisotropy are inclined to the plane of the crack it is found that the plastic zones as well as the stress and strain fields just around the blunted tip of the crack become non-symmetric. In these cases the peak strain...... on the blunted tip occurs off the center line of the crack, thus indicating that the crack may want to grow in a different direction. When the anisotropic axes are parallel to the crack symmetry is retained, but the plastic zones and the near-tip fields still differ from those predicted by standard isotropic...

  13. Growing Pains

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Heat expands and cold contracts: it’s a simple thermodynamic rule. But when temperatures swing from 300 K to near-absolute zero, this rule can mean a contraction of more than 80 metres across the LHC’s 27-km-long cryogenic system. Keeping this growth in check are compensators (a.k.a. bellows), which shrink and stretch in response to thermodynamic changes. Leak tests and X-rays now underway in the tunnel have revealed that these “joints” might be suffering from growing pains…   This 25-μm weld crack is thought to be the cause of the helium leaks. Prior to the LS1 warm-up, CERN’s cryogenic experts knew of two points in the machine’s cryogenic distribution system that were leaking helium. Fortunately, these leaks were sufficiently small, confined to known sub-sectors of the cryogenic line and – with help from the vacuum team (TE-VSC) – could easily be compensated for. But as the machine warmed up f...

  14. Root - shoot - signaling in Chenopodium rubrum L. as studied by 15O labeled water uptake

    International Nuclear Information System (INIS)

    Ohya, T.; Hayashi, Y.; Tanoi, K.; Rai, H.; Nakanishi, T.M.; Suzuki, K.; Albrechtova, J.T.P.; Wagner, E.

    2005-01-01

    Full text: It has been demonstrated with C. rubrum that the different organ systems are transmitting surface action potentials which might be the basis for systemic signal transduction. Shoot tip respectively root generated action potentials travel along the stem axis. Shoot tip generated action potentials arriving at the basis can be reflected and travel upwards. The radioactive labeling technique was established at the NIRS in Inage, Japan. About 2 GBq of 15 O labeled Hoagland's solution was supplied to the plant root or cut stem in a phytotron at 25 o C with 45 % of relative humidity and continuous light. By cutting the shoot apical bud and the apices of main side branches the uptake of 15 O labeled water was inhibited in plants with intact roots but not in plants with roots cut. Because of the short half-life of 15 O (2 min), experiments could be repeated in hourly intervals. Cutting the apex probably limits root water uptake via a hydraulic-electrochemical signal. The results are discussed with respect to the significance of a continuous communication between the root system and the shoot apical meristem(s) in the adaptation of plants to their environment. (author)

  15. High taxonomic diversity of cultivation-recalcitrant endophytic bacteria in grapevine field shoots, their in vitro introduction, and unsuspected persistence.

    Science.gov (United States)

    Thomas, Pious; Sekhar, Aparna C; Shaik, Sadiq Pasha

    2017-11-01

    Molecular and microscopic analyses reveal enormous non-cultivable endophytic bacteria in grapevine field shoots with functional significance. Diverse bacteria enter tissue cultures through surface-sterilized tissues and survive surreptitiously with varying taxonomic realignments. The study was envisaged to assess the extent of endophytic bacterial association with field shoot tissues of grapevine and the likelihood of introduction of such internally colonizing bacteria in vitro adopting molecular techniques targeting the non-cultivable bacterial community. PowerFood ® -kit derived DNA from surface-sterilized field shoot tips of grapevine Flame Seedless was employed in a preliminary bacterial class-specific PCR screening proving positive for major prokaryotic taxa including Archaea. Taxonomic and functional diversity were analyzed through whole metagenome profiling (WMG) which revealed predominantly phylum Actinobacteria, Proteobacteria, and minor shares of Firmicutes, Bacteroidetes, and Deinococcus-Thermus with varying functional roles ascribable to the whole bacterial community. Field shoot tip tissues and callus derived from stem segments were further employed in 16S rRNA V3-V4 amplicon taxonomic profiling. This revealed elevated taxonomic diversity in field shoots over WMG, predominantly Proteobacteria succeeded by Actinobacteria, Firmicutes, Bacteroidetes, and 15 other phyla including several candidate phyla (135 families, 179 genera). Callus stocks also displayed broad bacterial diversity (16 phyla; 96 families; 141 genera) bearing resemblance to field tissues with Proteobacterial dominance but a reduction in its share, enrichment of Actinobacteria and Firmicutes, disappearance of some field-associated phyla and detection of a few additional taxonomic groups over field community. Similar results were documented during 16S V3-V4 amplicon taxonomic profiling on Thompson Seedless field shoot tip and callus tissues. Video microscopy on tissue homogenates

  16. Can protoplast production from in vitro cultured shoots of Tanacetum vary during the season?

    Directory of Open Access Journals (Sweden)

    M. KESKITALO

    2008-12-01

    Full Text Available Two different experiments were carried out to study the production of protoplasts and the variation of protoplast yield from in vitro cultured shoot tips of tansy (Tanacetum vulgare L. and pyrethrum (Tanacetum cinerariifolium (Trevir. Schiltz-Bip. In the first experiment, light had more pronouced effect for tansy than for pyrethrum. When the donor tissues of tansy were cultured under high light intensity the leaves contained anthocyanin and became brown during enzyme maceration. In contrast, donor tissues cultured under low light intensity produced leaves without anthocyanin. Depending on the light intensity of donor tissues, on average 5.8 - 6.8 x 106 and 3.4 - 4.3 x 106 protoplasts were isolated from one gram of mesophyll leaves of tansy and pyrethrum, respectively. In the second experiment, the production of protoplasts from tansy and pyrethrum varied seasonally. The most successful season for the production of protoplasts from in vitro cultured shoot tips was between December and April, when also the highest number of protoplasts could be isolated. It was not possible to state whether Tanacetum species have rhythms, which could cause physiological or chemical changes for the in vitro grown shoot tips. However, some external or internal, possible seasonal-dependent stimuli may have caused variation in the number of protoplasts isolated from tansy and pyrethrum and favoured protoplast production during winter and spring.

  17. Low Vision Tips

    Science.gov (United States)

    ... this page: https://medlineplus.gov/lowvision.html MedlinePlus: Low Vision Tips We are sorry. MedlinePlus no longer maintains the For Low Vision Users page. You will still find health resources ...

  18. Diabetes: Dental Tips

    Science.gov (United States)

    Diabetes: Dental Tips For more copies contact: National Institute of Dental and Craniofacial Research National Oral Health Information Clearinghouse ... damage the gum and bone that hold your teeth in place and may lead to painful chewing ...

  19. Incontinence Treatment: Dietary Tips

    Science.gov (United States)

    ... helpful, please consider supporting IFFGD with a small tax-deductible donation. Lifestyle Changes Dietary Tips Medication Bowel ... arises requiring an expert’s care. © Copyright 1998-2018 International Foundation for Functional Gastrointestinal Disorders, Inc. (IFFGD). All ...

  20. Cell lineage patterns in the shoot meristem of the sunflower embryo in the dry seed

    International Nuclear Information System (INIS)

    Jegla, D.E.; Sussex, I.M.

    1989-01-01

    We mapped the fate of cells in the shoot meristem of the dry-seed embryo of sunflower, Helianthus annuus L. cv. Peredovic, using irradiation-induced somatic sectors. We analyzed 249 chlorophyll-deficient or glabrous (hairless) sectors generated in 236 plants. Most sectors observed in the inflorescence extended into vegetative nodes. Thus cell lineages that ultimately gave rise to reproductive structures also contributed to vegetative structures. No single sector extended the entire length of the shoot. Thus the shoot is not derived from one or a few apical initials. Rather, the position, vertical extent, and width of the sectors at different levels of the shoot suggest that the shoot is derived from three to four circumferential populations of cells in each of three cell layers of the embryo meristem. Sectors had no common boundaries even in plants with two or three independent sectors, but varied in extent and overlapped along the length of the shoot. Thus individual cells in a single circumferential population behaved independently to contribute lineages of different vertical extents to the growing shoot. The predicted number of circumferential populations of cells as well as the apparent cell number in each population was consistent with the actual number of cells in the embryo meristem observed in histological sections

  1. Variation in shoot tolerance mechanisms not related to ion toxicity in barley

    KAUST Repository

    Tilbrook, Joanne

    2017-09-27

    Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250mMNaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, withsome lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+: Na+ ratios).

  2. Variation in shoot tolerance mechanisms not related to ion toxicity in barley

    KAUST Repository

    Tilbrook, Joanne; Schilling, Rhiannon K.; Berger, Bettina; Garcia, Alexandre F.; Trittermann, Christine; Coventry, Stewart; Rabie, Huwaida; Brien, Chris; Nguyen, Martin; Tester, Mark A.; Roy, Stuart J.

    2017-01-01

    Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250mMNaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, withsome lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+: Na+ ratios).

  3. Evolutionary potential of root chemical defense: genetic correlations with shoot chemistry and plant growth.

    Science.gov (United States)

    Parker, J D; Salminen, J-P; Agrawal, Anurag A

    2012-08-01

    Root herbivores can affect plant fitness, and roots often contain the same secondary metabolites that act as defenses in shoots, but the ecology and evolution of root chemical defense have been little investigated. Here, we investigated genetic variance, heritability, and correlations among defensive phenolic compounds in shoot vs. root tissues of common evening primrose, Oenothera biennis. Across 20 genotypes, there were roughly similar concentrations of total phenolics in shoots vs. roots, but the allocation of particular phenolics to shoots vs. roots varied along a continuum of genotype growth rate. Slow-growing genotypes allocated 2-fold more of the potential pro-oxidant oenothein B to shoots than roots, whereas fast-growing genotypes had roughly equivalent above and belowground concentrations. Phenolic concentrations in both roots and shoots were strongly heritable, with mostly positive patterns of genetic covariation. Nonetheless, there was genotype-specific variation in the presence/absence of two major ellagitannins (oenothein A and its precursor oenothein B), indicating two different chemotypes based on alterations in this chemical pathway. Overall, the presence of strong genetic variation in root defenses suggests ample scope for the evolution of these compounds as defenses against root herbivores.

  4. Liquid shoot culture of Salvia officinalis L. for micropropagation and production of antioxidant compounds; effect of triacontanol

    Directory of Open Access Journals (Sweden)

    Izabela Grzegorczyk

    2011-01-01

    Full Text Available Liquid shoot culture of Salvia officinalis L. in MS medium containing IAA (0.1 mg l-1 and BAP (0.45 mg l-1 was developed and evaluated in relation to shoot multiplication and antioxidant compound (carnosic acid, carnosol and rosmarinic acid accumulation. In the liquid medium, on average, 3 new shoots per explant (shoot tip were obtained within 3 weeks. The shoots produced 8.2±0.02 mg of diterpenoids and 31.2±0.29 mg of rosmarinic acid per gram of dry weight. Shoot proliferation and diterpenoid content increased when triacontanol (5, 10 or 20 pg l-1 was added to the liquid medium. In optimum conditions (at 20 pg l-1 TRIA almost 7 shoots were formed per explant after 3 weeks. An increase in diterpenoid production (expressed as the sum of carnosol and carnosic acid ranged from 30% to 50% and dependended on triacontanol concentration tested. The level of diterpenoids in triacontanol-treated shoots was similar to the content of compounds in commercial herbal product (dried leaves of S. officinalis (10-12 mg g-1 dry wt. Triacontanol did not increase rosmarinic acid production, but the content of the phenolic as compound in shoots grown in liquid culture (31 mg g-1 dry wt was even 24 times higher compared to samples of dried leaves of S. officinalis plants. We also demonstrated that the highest amounts of CA, Car and RA were accumulated in young, top parts of sage shoots. This observation could be useful for improving the selection of material for the extraction of natural antioxidants from S. officinalis.

  5. Branch age and light conditions determine leaf-area-specific conductivity in current shoots of Scots pine.

    Science.gov (United States)

    Grönlund, Leila; Hölttä, Teemu; Mäkelä, Annikki

    2016-08-01

    Shoot size and other shoot properties more or less follow the availability of light, but there is also evidence that the topological position in a tree crown has an influence on shoot development. Whether the hydraulic properties of new shoots are more regulated by the light or the position affects the shoot acclimation to changing light conditions and thereby to changing evaporative demand. We investigated the leaf-area-specific conductivity (and its components sapwood-specific conductivity and Huber value) of the current-year shoots of Scots pine (Pinus sylvestris L.) in relation to light environment and topological position in three different tree classes. The light environment was quantified in terms of simulated transpiration and the topological position was quantified by parent branch age. Sample shoot measurements included length, basal and tip diameter, hydraulic conductivity of the shoot, tracheid area and density, and specific leaf area. In our results, the leaf-area-specific conductivity of new shoots declined with parent branch age and increased with simulated transpiration rate of the shoot. The relation to transpiration demand seemed more decisive, since it gave higher R(2) values than branch age and explained the differences between the tree classes. The trend of leaf-area-specific conductivity with simulated transpiration was closely related to Huber value, whereas the trend of leaf-area-specific conductivity with parent branch age was related to a similar trend in sapwood-specific conductivity. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Brand Luise H

    2010-12-01

    Full Text Available Abstract Background Throughout their lives plants produce new organs from groups of pluripotent cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS and the CLAVATA (CLV proteins. This regulatory circuit is further fine-tuned by morphogenic signals such as hormones and sugars. Results Here we show that a family of four plant-specific proteins, encoded by the FANTASTIC FOUR (FAF genes, has the potential to regulate shoot meristem size in Arabidopsis thaliana. FAF2 and FAF4 are expressed in the centre of the shoot meristem, overlapping with the site of WUS expression. Consistent with a regulatory interaction between the FAF gene family and WUS, our experiments indicate that the FAFs can repress WUS, which ultimately leads to an arrest of meristem activity in FAF overexpressing lines. The finding that meristematic expression of FAF2 and FAF4 is under negative control by CLV3 further supports the hypothesis that the FAFs are modulators of the genetic circuit that regulates the meristem. Conclusion This study reports the initial characterization of the Arabidopsis thaliana FAF gene family. Our data indicate that the FAF genes form a plant specific gene family, the members of which have the potential to regulate the size of the shoot meristem by modulating the CLV3-WUS feedback loop.

  7. The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana.

    Science.gov (United States)

    Wahl, Vanessa; Brand, Luise H; Guo, Ya-Long; Schmid, Markus

    2010-12-22

    Throughout their lives plants produce new organs from groups of pluripotent cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS) and the CLAVATA (CLV) proteins. This regulatory circuit is further fine-tuned by morphogenic signals such as hormones and sugars. Here we show that a family of four plant-specific proteins, encoded by the FANTASTIC FOUR (FAF) genes, has the potential to regulate shoot meristem size in Arabidopsis thaliana. FAF2 and FAF4 are expressed in the centre of the shoot meristem, overlapping with the site of WUS expression. Consistent with a regulatory interaction between the FAF gene family and WUS, our experiments indicate that the FAFs can repress WUS, which ultimately leads to an arrest of meristem activity in FAF overexpressing lines. The finding that meristematic expression of FAF2 and FAF4 is under negative control by CLV3 further supports the hypothesis that the FAFs are modulators of the genetic circuit that regulates the meristem. This study reports the initial characterization of the Arabidopsis thaliana FAF gene family. Our data indicate that the FAF genes form a plant specific gene family, the members of which have the potential to regulate the size of the shoot meristem by modulating the CLV3-WUS feedback loop.

  8. Shooting mechanisms in Nature : A systematic review

    NARCIS (Netherlands)

    Sakes, A.; van der Wiel, M.; Henselmans, P.W.J.; van Leeuwen, J.L.; Dodou, D.; Breedveld, P.

    2016-01-01

    Background
    In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

  9. Current perspectives on shoot branching regulation

    Directory of Open Access Journals (Sweden)

    Cunquan YUAN,Lin XI,Yaping KOU,Yu ZHAO,Liangjun ZHAO

    2015-03-01

    Full Text Available Shoot branching is regulated by the complex interactions among hormones, development, and environmental factors. Recent studies into the regulatory mecha-nisms of shoot branching have focused on strigolactones, which is a new area of investigation in shoot branching regulation. Elucidation of the function of the D53 gene has allowed exploration of detailed mechanisms of action of strigolactones in regulating shoot branching. In addition, the recent discovery that sucrose is key for axillary bud release has challenged the established auxin theory, in which auxin is the principal agent in the control of apical dominance. These developments increase our understan-ding of branching control and indicate that regulation of shoot branching involves a complex network. Here, we first summarize advances in the systematic regulatory network of plant shoot branching based on current information. Then we describe recent developments in the synthesis and signal transduction of strigolactones. Based on these considerations, we further summarize the plant shoot branching regulatory network, including long distance systemic signals and local gene activity mediated by strigolactones following perception of external envi-ronmental signals, such as shading, in order to provide a comprehensive overview of plant shoot branching.

  10. thidiazuron improves adventitious bud and shoot regeneration

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Induction of adventitious buds and shoots from intact leaves and stem internode segments of two recalcitrant. Ugandan sweetpotato (Ipomoea batatas L.) cultivars was investigated in vitro on Murashige and Skoog (MS) medium, supplemented with 3 different levels (0.5, 2.0 and 4.0 µM) of Thidiazuron (TDZ). Shoots were.

  11. Shoot organogenesis in oleaster (Elaeagnus angustifolia L.)

    African Journals Online (AJOL)

    STORAGESEVER

    2009-02-04

    Feb 4, 2009 ... Regenerated plantlets were acclimatized and successfully transplanted to soil. Key words: shoot organogenesis, callus, ... saline and alkaline soils (Economou and Maloupa, 1995). Its fruits have been used as a .... cally inert compounds as reported by Kaminek (1992). Direct shoot organogenesis without ...

  12. Differences between height- and light-dependent changes in shoot traits in five deciduous tree species.

    Science.gov (United States)

    Osada, Noriyuki; Okabe, Yoshihiko; Hayashi, Daisuke; Katsuyama, Tomonori; Tokuchi, Naoko

    2014-01-01

    The effects of tree height on shoot traits may in some cases differ in magnitude and direction from the effects of light. Nevertheless, general patterns of change in shoot traits in relation to variations in height and light have not so far been revealed. A comprehensive analysis of the differences between the effects of height and light on a range of leaf and shoot traits is important for the scaling of these traits to individual trees. We investigated the biomass allocation and structure of current-year shoots at the top of the crowns of five deciduous tree species in Japan. Height effect was investigated by comparing shoot traits among trees of different heights growing under a high light environment. The effects of light were examined by comparing saplings growing in high- and low-light environments. The effects of light were significant for most traits, while those of height were not significant for some traits. The magnitudes of the effects of light were larger than those of height for most traits related to biomass allocation. There was an extreme difference between the effects of height and light in the direction of change in the length of current-year shoots and in the number of standing leaves. The measures of both parameters increased with the increase in light, but decreased with the increase in tree height. Thus, the effects of height and light on diverse traits at the level of current-year shoots were not always similar. These results suggest that great care must be taken when scaling shoot traits from small trees to tall trees because the effects of height and light can be complex.

  13. Mass Shootings, Mental Illness, and Gun Control.

    Science.gov (United States)

    Philpott-Jones, Sean

    2018-03-01

    In the wake of the Stoneman Douglas School shooting, Republican and Democratic leaders-like the American electorate they represent-remain sharply divided in their responses to gun violence. They are united in their condemnation of these mass shootings, but they disagree about whether stricter or looser gun control laws are the answer. Those on the right side of the political aisle suggest that the issue is one of mental illness rather than gun control. Conversely, those who are more liberal or progressive in their political learnings are quick to condemn attempts to reframe the issue of mass shootings as a mental health problem. Both sides are wrong. Mass shootings are indeed partially a mental health problem, albeit one poorly addressed by our current laws and policies. But the solution to mass shootings also needs to consider strategies that may reduce gun violence in general. © 2018 The Hastings Center.

  14. Magnet pole tips

    Science.gov (United States)

    Thorn, Craig E.; Chasman, Chellis; Baltz, Anthony J.

    1984-04-24

    An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  15. Improved flare tip design

    Energy Technology Data Exchange (ETDEWEB)

    Gogolek, P. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2004-07-01

    This paper discusses the testing procedures and development of an improved flare tip design. Design objectives included performance equal to or better than utility flares at low wind speed; conversion efficiency; fuel slip; smoking; significant improvement at high wind speed; and no increase in trace emissions. A description of the testing facility of the flare tip was provided, with reference to the fact that the facility allowed for realistic near full scale gas flares in a single-pass flare test facility. Other details of the facility included: an adjustable ceiling; high capacity variable speed fan; sampling ports along working section in stack; windows along working section; and air cooled walls, floor, and ceiling. The fuels used in the flare tip included natural gas, propane, gasoline and inert gases. Details of wind speed, appurtenances and turbulence generating grids were presented, with reference to continuous gas emission measurements. A list of design constraints was provided. Flare performance included wind speed, turbulence and fuel composition. A chart of conversion inefficiencies with a correlation of wind speed and turbulence, fuel flow and pipe size was also presented. Several new tip designs were fabricated for testing, with screening tests for comparison to basic pipe and ranking designs. Significant improvements were found in one of the new designs, including results with 30 per cent propane in fuel. Emissions reduction from 10 to 35 per cent were noted. It was concluded that future work should focus on evaluating improved tip for stability at low wind speeds. Fuel slips are the primary source of emissions, and it was recommended that further research is necessary to improve existing flare tips. tabs, figs.

  16. Productivity tips for developers

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    I like to read about productivity tools and techniques, but the problem is - most of them are completely overrated, the tips are not that useful or they are too difficult to implement. But, sometimes I can find some stuff that really makes me think "damn, how could I live without this before?!". Today, I would like to share some of them and hopefully hear about the tips and tricks that you use. Maybe we can find a way to share them somehow (github repo/forum)?

  17. Sports Dehydration Safety Tips

    Science.gov (United States)

    Sports Dehydration Safety Tips Everything you need to know to keep your kids safe from dehydration when playing sports. To keep kids in top ... to stay hydrated by drinking plenty of fluids. Dehydration occurs when a body loses more water than ...

  18. Rapid multiplication of Dalbergia sissoo Roxb.: a timber yielding tree legume through axillary shoot proliferation and ex vitro rooting.

    Science.gov (United States)

    Vibha, J B; Shekhawat, N S; Mehandru, Pooja; Dinesh, Rachana

    2014-01-01

    An efficient and improved method for in vitro propagation of mature tree of Dalbergia sissoo, an ecologically and commercially important timber yielding species, has been developed through axillary shoot proliferation. Bud breaking occurred from nodal shoot segments derived from rejuvenated shoots produced during early spring from a 20-25-year-old lopped tree, on MS medium containing 8.88 μM benzylaminopurine (BAP). Multiple shoots differentiated (20-21shoots/node) on re-culture of explants on half-strength agar gelled amended MS medium with a combination of 2.22 μM of BAP and 0.002 μM of thidiazuron (TDZ) with 1.0 mM each of Ca(NO3)2, K2SO4, KCl, and NH4(SO4)2. The maximum shoot multiplication (29-30 shoots/node) was achieved on subculturing in the above mentioned but liquid medium. Furthermore, the problem of shoot tip necrosis and defoliation observed on solid medium were overcome by the use of liquid medium. Ex vitro rooting was achieved on soilrite after basal treatment of microshoots with 984 μM of indole-3-butyric acid (IBA) for 2 min. About 90 % microshoots were rooted on soilrite within 2-3 weeks under the greenhouse conditions. From 20 nodal shoot segments, about 435 hardened plants were acclimatized and transplanted. This is the first report for rapid in vitro propagation of mature trees of D. sissoo on liquid medium followed by ex vitro rooting.

  19. PERBANDINGAN JUMP SHOOT DENGAN AWALAN DAN TANPA AWALAN TERHADAP PENINGKATAN KETEPATAN SHOOTING DALAM PERMAINAN BOLABASKET

    Directory of Open Access Journals (Sweden)

    I Gusti Ngurah Agung Cahya Prananta

    2015-01-01

    Full Text Available The effectiveness of  jump-shoot technique step jump shoot and still jump shoot in a game is still questionable,  because many different assumptions arise. One opinion stated that step jump shoot was more effective and the other stated that and still jump shoot was more efective. Therefore it is necessary to do research on the analysis of the results of step jump shoot and and still jump shoot to improve the accuracy of shooting in a basketball. The experimental research had been conducted on 20samples of people whowere selected randomly from the men's basketball club of the Faculty of Physical Educationand Health of Teacher Training Institute PGRI Bali. Samples were divided into two groups each  consisting of 10 people. Group I was given training step  jump shoot four sets of 10 reps  and Group II training still jump shoot four sets of 10 reps. The data before and after treatment were tested by SPSS computer program. The data were normally distributed and homogeneous so further tested using pairedt-test to compare the average values?? before and after training between each group, while the independent t-test was used to determine differences in mean values?? between the two groups. Paired t-test resulted the obtained data were significantly increased in both treatment groups p=0,001 in Group I and p=0,000 in Group II (p <0.05. Results of independent t-test found that both groups before training did not differ significantly p=0,926 (p>0.05 and after training both groups equally improve the accuracy of shooting because p=0,133 (p>0.05. It was concluded that botht raining improved the shooting accuracy and there was no difference between the effect of step jumps hoot and still jump shoot toward the shooting accuracy. It was suggested to improve the shooting accuracy in basketball used step jump shoot training and still jump shoot training four sets of 10 reps with a training frequency of 4 times a week for 6 weeks

  20. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... or bypass, without the risks that accompany open surgery. TIPS is a minimally invasive procedure that typically has a shorter recovery time than surgery. Your TIPS should have less of an effect ...

  1. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... then placed in this tunnel to keep the pathway open. Patients who typically need a TIPS have ... and stomach. A TIPS procedure involves creating a pathway through the liver that connects the portal vein ( ...

  2. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... and/or hydrothorax (in the chest). Budd-Chiari syndrome , a blockage in one or more veins that ... intentionally to solve the problem. Although extremely rare, children may also require a TIPS procedure. TIPS in ...

  3. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... filtered out by the liver. The TIPS may cause too much of these substances to bypass the ...

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... the esophagus and stomach. A TIPS procedure involves creating a pathway through the liver that connects the ... diseases. This can result in significant challenges in creating the TIPS. top of page Additional Information and ...

  5. Tips for Living with Scleroderma

    Science.gov (United States)

    ... Patients Tips for Living Tips for Living with Scleroderma Ways to help manage your symptoms The Scleroderma ... help find improved therapies and a cure for scleroderma! Your gift today will be matched to have ...

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... TIPS. top of page What are some common uses of the procedure? A TIPS is used to ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... recovery time than surgery. Your TIPS should have less of an effect than open surgical bypass on ...

  8. [Genetic regulation of plant shoot stem cells].

    Science.gov (United States)

    Al'bert, E V; Ezhova, T A

    2013-02-01

    This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos. Unconventional concepts of plant stem cells are considered.

  9. Mass shooting and mass media : does media coverage of mass shootings inspire copycat crimes?

    OpenAIRE

    Mesoudi, A.

    2013-01-01

    In December 2012, twenty elementary school children and six adult staff members were shot and killed by a single individual at a school in Connecticut. Although this horrific event was met with widespread shock, Americans are sadly all too familiar with such mass shootings. From Columbine in 1999, to Virginia Tech in 2007, to the Colorado cinema shootings earlier in 2012, mass shootings seem to occur with alarming regularity. And although they appear to afflict the United States more than mos...

  10. Branch architecture in Ginkgo biloba: wood anatomy and long shoot-short shoot interactions.

    Science.gov (United States)

    Little, Stefan A; Jacobs, Brooke; McKechnie, Steven J; Cooper, Ranessa L; Christianson, Michael L; Jernstedt, Judith A

    2013-10-01

    Ginkgo, centrally placed in seed plant phylogeny, is considered important in many phylogenetic and evolutionary studies. Shoot dimorphism of Ginkgo has been long noted, but no work has yet been done to evaluate the relationships between overall branch architecture and wood ring characters, shoot growth, and environmental conditions. • Branches, sampled from similar canopy heights, were mapped with the age of each long shoot segment determined by counting annual leaf-scar series on its short shoots. Transverse sections were made for each long shoot segment and an adjacent short shoot; wood ring thickness, number of rings, and number of tracheids/ring were determined. Using branch maps, we identified wood rings for each long shoot segment to year and developmental context of each year (distal short shoot growth only vs. at least one distal long shoot). Climate data were also analyzed in conjunction with developmental context. • Significantly thicker wood rings occur in years with distal long shoot development. The likelihood that a branch produced long shoots in a given year was lower with higher maximum annual temperature. Annual maximum temperature was negatively correlated with ring thickness in microsporangiate trees only. Annual minimum temperatures were correlated differently with ring thickness of megasporangiate and microsporangiate trees, depending on the developmental context. There were no significant effects associated with precipitation. • Overall, developmental context alone predicts wood ring thickness about as well as models that include temperature. This suggests that although climatic factors may be strongly correlated with wood ring data among many gymnosperm taxa, at least for Ginkgo, correlations with climate data are primarily due to changes in proportions of shoot developmental types (LS vs. SS) across branches.

  11. Characterization of metal-coated fiber tip for NSOM lithography by tip-to-tip scan

    International Nuclear Information System (INIS)

    Kubicova, I.; Pudis, D.; Suslik, L.; Skriniarova, J.

    2011-01-01

    For the optical field characterization, a tip-to-tip scan of two metal-coated fiber tips with circular aperture at the apex was performed. The optical field irradiated from the fiber probe in illumination mode was analyzed by NSOM represented by fiber probe in collection mode. The near-field intensity profile of the source fiber tip in the plane perpendicular to the axis of the tip was taken. Experimental stage requires high resolution 3D motion system controlled by computer (Fig. 1). The source and the detector fiber tip were placed on the moving and static part of the 3D nanoposition system, respectively. As a light source, a modulated 473 nm DPSS laser was used. After the source fiber tip characterization, the NSOM lithography was performed. In the experimental setup from Fig. 1, the detector fiber tip was replaced by a sample fixed in a vacuum holder. As a sample, a 600 nm positive photoresist AZ 5214E was spin-coated on a GaAs substrate. Exposure was carried out by irradiation of the sample at desired positions through the fiber tip aperture. The sample was developed in AZ 400K developer for 30 s and rinsed in DI water. A promising tip-to-tip scanning technique for characterization of metal-coated fiber tips with aperture at the apex was presented. Nearly-circular aperture shapes were documented from NSOM measurements with diameter estimated to be less than 460 nm. By knowing the source-detector distance and the FWHM of the near-field intensity profile, the tip-to-tip scan proves an easy and fast method to analyze the fiber tip aperture properties. The fiber tip resolution was confirmed by preparation of 2D planar structures in thin photoresist layer, where the NSOM lithography uses the metal-coated fiber tip characterized in previous section. (authors)

  12. Tip-modified Propellers

    DEFF Research Database (Denmark)

    Andersen, Poul

    1999-01-01

    The paper deals with tip-modified propellers and the methods which, over a period of two decades, have been applied to develop such propellers. The development is driven by the urge to increase the efficiency of propellers and can be seen as analogous to fitting end plates and winglets to aircraft...... propeller, have efficiency increases of a reasonable magnitude in both open-water and behind-ship conditions....

  13. Multiple shoot cultures of Atropa belladonna: Effect of physico-chemical factors on growth and alkaloid formation

    International Nuclear Information System (INIS)

    Benjamin, B.D.; Roja, P.C.; Heble, M.R.; Chandha, M.S.

    1987-01-01

    Multiple shoot cultures were established from shoot tip and axillary meristem of the plant Atropa belladonna. The cultures were initially raised on agar medium and subsequently maintained on liquid medium of Murashige and Skoog (1962) supplemented with BA. These cultures were subjected to different doses of -y-irradiation. Recovery from the radiation effects was observed in tissues subjected to 29 Gy during four successive passages. Plant growth regulators influenced the growth and morphogenetic events of the tissues. The precursors of tropane alkaloids marginally increased the alkaloid synthesis during the stationary phase of growth. Shoot cultures, established from different field grown plants varying in alkaloid content, were morphologically similar and did not exhibit the parental characteristics with respect to alkaloid formation

  14. Shooting Mechanisms in Nature: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Aimée Sakes

    Full Text Available In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these mechanisms fulfill.We systematically searched the literature using Scopus and Web of Knowledge to retrieve articles about solid projectiles that either are produced in the body of the organism or belong to the body and undergo a ballistic phase. The shooting mechanisms were categorized based on the energy management prior to and during shooting.Shooting mechanisms were identified with projectile masses ranging from 1·10-9 mg in spores of the fungal phyla Ascomycota and Zygomycota to approximately 10,300 mg for the ballistic tongue of the toad Bufo alvarius. The energy for shooting is generated through osmosis in fungi, plants, and animals or muscle contraction in animals. Osmosis can be induced by water condensation on the system (in fungi, or water absorption in the system (reaching critical pressures up to 15.4 atmospheres; observed in fungi, plants, and animals, or water evaporation from the system (reaching up to -197 atmospheres; observed in plants and fungi. The generated energy is stored as elastic (potential energy in cell walls in fungi and plants and in elastic structures in animals, with two exceptions: (1 in the momentum catapult of Basidiomycota the energy is stored in a stalk (hilum by compression of the spore and droplets and (2 in Sphagnum energy is mainly stored in compressed air. Finally, the stored energy is transformed into kinetic energy of the projectile using a catapult mechanism delivering up to 4,137 J/kg in the osmotic shooting mechanism in cnidarians and 1,269 J/kg in the muscle-powered appendage strike of the mantis shrimp Odontodactylus scyllarus. The launch accelerations range from 6.6g in the frog Rana pipiens to 5,413,000g in

  15. The Mental Health Consequences of Mass Shootings.

    Science.gov (United States)

    Lowe, Sarah R; Galea, Sandro

    2017-01-01

    Mass shooting episodes have increased over recent decades and received substantial media coverage. Despite the potentially widespread and increasing mental health impact of mass shootings, no efforts to our knowledge have been made to review the empirical literature on this topic. We identified 49 peer-reviewed articles, comprised of 27 independent samples in the aftermath of 15 mass shooting incidents. Based on our review, we concluded that mass shootings are associated with a variety of adverse psychological outcomes in survivors and members of affected communities. Less is known about the psychological effects of mass shootings on indirectly exposed populations; however, there is evidence that such events lead to at least short-term increases in fears and declines in perceived safety. A variety of risk factors for adverse psychological outcomes have been identified, including demographic and pre-incident characteristics (e.g., female gender and pre-incident psychological symptoms), event exposure (e.g., greater proximity to the attack and acquaintance with the deceased), and fewer psychosocial resources (e.g., emotion regulation difficulties and lower social support). Further research that draws on pre-incident and longitudinal data will yield important insights into the processes that exacerbate or sustain post-incident psychological symptoms over time and provide important information for crisis preparedness and post-incident mental health interventions. © The Author(s) 2015.

  16. Selective Deactivation of Gibberellins below the Shoot Apex is Critical to Flowering but Not to Stem Elongation of Lolium

    DEFF Research Database (Denmark)

    King, Rod W; Mander, Lewis N; Asp, Torben

    2008-01-01

    in their effectiveness for flowering because they are deactivated by C-2 hydroxylation below the shoot apex. In contrast, GA5 is effective because of its structural protection at C-2. Excised vegetative shoot tips rapidly degrade [14C]GA1, [14C]GA4, and [14C]GA20 (>80% in 6 h), but not [14C]GA5. Coincidentally, genes...... encoding two 2β-oxidases and a putative 16-17-epoxidase were most expressed just below the shoot apex (4 mm), expression of these GA deactivation genes is reduced, so allowing GA1 and GA4 to promote sub-apical stem elongation. Subsequently, GA degradation declines...... in florally induced shoot tips and these GAs can become active for floral development. Structural changes which stabilize GA4 confirm the link between florigenicity and restricted GA 2β-hydroxylation (e.g. 2 -hydroxylation and C-2 di-methylation). Additionally, a 2-oxidase inhibitor (Trinexapac Ethyl...

  17. Photosynthesis of a scots pine shoot: the effect of shoot inclination on the photosynthetic response of a shoot subjected to direct radiation

    International Nuclear Information System (INIS)

    Oker-Blom, P.; Kellomaki, S.; Smolander, H.

    1983-01-01

    A set of photosynthetic responses of a Scots pine (Pinus sylvestris L.) shoot to light was derived from the shoot geometry and the photosynthetic response of a single needle. Computations showed that the shape of the photosynthesis light-curves varies substantially depending on the direction of radiation relative to the shoot position. Differences in the initial and maximum rates of photosynthesis were due to changes in the effective projection area and the irradiated fraction of the shoot, respectively

  18. Carbon utilization by fruit limits shoot growth in alternate-bearing citrus trees.

    Science.gov (United States)

    Martínez-Alcántara, Belén; Iglesias, Domingo J; Reig, Carmina; Mesejo, Carlos; Agustí, Manuel; Primo-Millo, Eduardo

    2015-03-15

    Fruit load in alternate-bearing citrus trees is reported to alter shoot number and growth during spring, summer, and autumn flushes, and the source-sink balance, which affects the storage and mobilization of reserve nutrients. The aim of this work was to assess the extent of shoot growth inhibition resulting from the presence of fruits in 'Moncada' mandarin trees loaded with fruit (ON) or with very light fruit load (OFF), and to identify the role of carbohydrates and nitrogenous compounds in the competition between fruits and shoots. Growth of reproductive and vegetative organs was measured on a monthly basis. (13)C- and (15)N-labeled compounds were supplied to trace the allocation of reserve nutrients and subsequent translocation from source to sink. At the end of the year, OFF trees produced more abundant flushes (2.4- and 4.9-fold higher in number and biomass, respectively) than ON trees. Fruits from ON trees accumulated higher C amounts at the expense of developing flushes, whereas OFF trees exhibited the opposite pattern. An inverse relationship was identified between the amount of C utilized by fruits and vegetative flush growth. (13)C-labeling revealed an important role for mature leaves of fruit-bearing branches in supporting shoot/fruit growth, and the elevated sink strength of growing fruits on shoots. N availability for vegetative shoots was not affected by the presence or absence of fruits, which accumulated important amounts of (15)N. In conclusion, our results show that shoot growth is resource-limited as a consequence of fruit development, and vegetative-growth inhibition is caused by photoassimilate limitation. The competence for N is not a decisive factor in limiting vegetative growth under the experimental conditions of this study. Copyright © 2014 Elsevier GmbH. All rights reserved.

  19. Contagion in Mass Killings and School Shootings.

    Directory of Open Access Journals (Sweden)

    Sherry Towers

    Full Text Available Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts.Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed. We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event.We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015. We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001. All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

  20. Contagion in Mass Killings and School Shootings.

    Science.gov (United States)

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event. We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015). We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001). All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

  1. Youth Responses to School Shootings: A Reviw

    DEFF Research Database (Denmark)

    Travers, Áine

    2018-01-01

    PURPOSE OF REVIEW:This paper aims to synthesize research relating to youth responses to school shootings between 2014 and 2017. The main questions it addresses are how such events impact young people psychologically, and what risk or protective factors may contribute to different trajectories...... of recovery? RECENT FINDINGS:Recent research suggests that most young people exposed to school shootings demonstrate resilience, exhibiting no long-term dysfunction. However, a minority will experience severe and chronic symptoms. The likelihood of experiencing clinically significant reactions is influenced...

  2. Cryopreservation of in vitro-grown shoot tips of apricot (Prunus ...

    African Journals Online (AJOL)

    akpobome

    2013-03-20

    Mar 20, 2013 ... cool white fluorescent lamps for 16 h photo period at 28 ± 2°C in growth cabinets. After four ... using an ultraviolet–visible (UV–Vis) transilluminator. Polymerase chain .... even though increasing dehydration time led to damage.

  3. Control of lethal browning by using ascorbic acid on shoot tip ...

    African Journals Online (AJOL)

    SAM

    2014-04-16

    Apr 16, 2014 ... vanillin coumurin, P-coumaric acid and phenol (Khalil et al., 2007). Browning reactions and astringency of the fruit caused by phenolic compounds are .... treatment (Table 2) and (Figure 1). It is well established that injured tissues normally stimulate the production of phenols (Dodds and Roberts, 1995).

  4. Blueberry red ringspot virus Eliminated from Highbush Blueberry by Shoot Tip Culture

    Czech Academy of Sciences Publication Activity Database

    Špak, Josef; Pavingerová, Daniela; Přibylová, Jaroslava; Špaková, Vlastimila; Paprštein, F.; Sedlák, J.

    2014-01-01

    Roč. 50, č. 4 (2014), s. 174-178 ISSN 1212-2580 Institutional support: RVO:60077344 Keywords : BRRV * in vitro * Vaccinium corymbosum L. Subject RIV: EE - Microbiology, Virology Impact factor: 0.597, year: 2014

  5. Use of protoplast, cell, and shoot tip culture in an elm germ plasm improvement program

    Science.gov (United States)

    R. Daniel Lineberger; M.B. Sticklen; P.M. Pijut; Mark A. Kroggel; C.V.M. Fink; S.C. Domir

    1990-01-01

    An elm germplasm improvement program was established using three distinct approaches: (1) development of protoplast regeneration protocols with the goal of attempting somatic hybridization between Ulmus americana and disease resistant hybrids; (2) evaluation of the extent of somaclonal variation in plants regenerated from protoplasts; and (3)...

  6. Improved droplet-vitrification and histological studies of cryopreserved shoot tips of cultivated Jerusalem artichoke genotypes

    Science.gov (United States)

    Germplasm conservation of Jerusalem artichoke (Helianthus tuberosus L.) is crucial to preserve genetic diversity and to secure materials for genetic improvement. Long-term conservation is accomplished through cryopreservation, storing cells or tissues at an ultralow temperature in liquid nitrogen (-...

  7. Cryopreservation of in vitro-grown shoot tips of apricot (Prunus ...

    African Journals Online (AJOL)

    akpobome

    2013-03-20

    Mar 20, 2013 ... Thus, they can be preserved in such a state for a long period (Sakai, 1995). Many new cryopreservation ..... formation of intracellular ice crystals during rapid cooling in LN (Wilkinson et al., 1998). Effect preculture and ..... Cryopreservation of protocorm-like bodies. (PLBs) of Phalaenopsis bellina. (Rchb.f.) ...

  8. Melatonin enhances the recovery of cryopreserved shoot tips of American elm (Ulmus Americana L.)

    Science.gov (United States)

    Climate change and the global migrations of people and goods have exposed trees to new diseases and abiotic challenges that threaten the survival of species. In vitro germplasm storage via cryopreservation is an effective tool to ensure conservation of tree species, but plant cells and tissues are e...

  9. Droplet-vitrification and morphohistological studies of cryopreserved shoot tips of cultivated and wild pineapple genotypes

    Science.gov (United States)

    Germplasm conservation of pineapple [Ananas comosus (L.) Mer.] is crucial to preserve the genus’ genetic diversity to secure material for genetic improvement and to support innovative and new research. Long-term conservation is accomplished through cryopreservation that is done by storing cells or t...

  10. AERODYNAMICS OF WING TIP SAILS

    Directory of Open Access Journals (Sweden)

    MUSHTAK AL-ATABI

    2006-06-01

    Full Text Available Observers have always been fascinated by soaring birds. An interesting feature of these birds is the existence of few feathers extending from the tip of the wing. In this paper, small lifting surfaces were fitted to the tip of a NACA0012 wing in a fashion similar to that of wing tip feathers. Experimental measurements of induced drag, longitudinal static stability and trailing vortex structure were obtained.The tests showed that adding wing tip surfaces (sails decreased the induced drag factor and increased the longitudinal static stability. Results identified two discrete appositely rotated tip vortices and showed the ability of wing tip surfaces to break them down and to diffuse them.

  11. Tips for Starting Physical Activity

    Science.gov (United States)

    ... Legislative Information Advisory & Coordinating Committees Strategic Plans & Reports Research Areas FAQs ... Starting Physical Activity Related Topics Section Navigation Tips to Help You Get Active ...

  12. Supplies should match growing demand

    International Nuclear Information System (INIS)

    Rasmusen, H.J.

    1997-01-01

    The natural gas industry is currently enjoying healthy growth prospects. Not only is the demand for natural gas steadily growing; the outlook for increasing gas reserves is promising as well. The success of natural gas in the marketplace reflects, on one hand, continuous attention paid to public and customer requirements and, on the other hand, the ability of the gas industry to direct technological developments toward the increasing public demand for gas at competitive market prices supplied in a reliable, safe and environmentally friendly manner. In the past, the gas industry has been involved in the development of technologies for everything from gas production to the end user and from borehole to burner tip, and the author believes that the industry must continue or even increase its emphasis on technology in the future in order to capture new market opportunities. He explains this by looking at the supply side, the demand side and the structural side of the business

  13. Growth of and partitioning between shoot and storage root of carrot in a northern climate

    Directory of Open Access Journals (Sweden)

    T. SUOJALA

    2008-12-01

    Full Text Available Matching the growth pattern of a vegetable cultivar with the seasonal changes in climate is a prerequisite for successful yield production in a northern climate. This paper describes the growth characteristics of two carrot cultivars in relation to climatic conditions in two years, with special reference to the factors associated with high yield. Cv. Fontana produced twice as large a leaf area and shoot weight as cv. Panther. Increased partitioning to shoot in the former cultivar also resulted in a higher root yield. Uniformity in relative growth rates during the period of analysis suggests that intervarietal differences in the shoot to root ratio and in the yield potential appear very early. Nearly half of the root weight at final harvest was gained after mid-August, when temperature and daily irradiance began to decrease. A large leaf area may ensure better utilisation of diminishing growth resources at the end of the growing season. In the more favourable growing season, 1997, plants invested more in leaf production than they did in 1996: shoot fresh and dry weights were considerably higher but leaf area was not much higher.;

  14. Lead Pollution of Shooting Range Soils

    African Journals Online (AJOL)

    NICOLAAS

    range. Most of the shooting range soils contained high levels of Pb in the range above 2000 mg kg–1 far exceeding the United States ... N. Sehube, R. Kelebemang, O. Totolo, M. Laetsang, O. Kamwi and P. Dinake,. 21 ..... Eng. Sci., 1999, 16,.

  15. Improving adventitious shoot regeneration from cultured leaf ...

    African Journals Online (AJOL)

    The effect of various concentrations of thidiazuron (TDZ) with or without 2.7 μM of α-naphthalene acetic acid (NAA) on adventitious shoot formation of two Petunia hybrida cultivars was studied. Seeds from 'Daddy Blue' and 'Dreams White' cultivars were germinated in vitro. Expanded leaves from both seedlings and ...

  16. Adventitious shoots induction and plant regeneration from ...

    African Journals Online (AJOL)

    A highly efficient regeneration system is a prerequisite step for successful genetic transformation of watermelon cultivars (Citrullus lanatus L.). The objective of this study was to establish efficient in vitro plant regeneration for three watermelon cultivars. To achieve optimal conditions for adventitious shoot induction, the ...

  17. School Shootings; Standards Kill Students and Society

    Science.gov (United States)

    Angert, Betsy L.

    2008-01-01

    School shootings have been in the news of late. People ponder what occurs in classrooms today. Why would a young person wish to take a life? Within educational institutions, the killings are a concern. In our dire attempt to teach the children and ensure student success, it seems many of our offspring are lost. Some students feel separate from…

  18. Growing media [Chapter 5

    Science.gov (United States)

    Douglass F. Jacobs; Thomas D. Landis; Tara Luna

    2009-01-01

    Selecting the proper growing medium is one of the most important considerations in nursery plant production. A growing medium can be defined as a substance through which roots grow and extract water and nutrients. In native plant nurseries, a growing medium can consist of native soil but is more commonly an "artificial soil" composed of materials such as peat...

  19. Adolescent mass shootings: developmental considerations in light of the Sandy Hook shooting.

    Science.gov (United States)

    Rice, Timothy R; Hoffman, Leon

    2015-05-01

    Adolescent mass shootings are a special subset of mass killings, which continue despite significant preventative public health efforts. It is often held that these individuals have few salient warning signs that could have been identified. This piece proposes that mass shootings committed by adolescent and post-adolescent young males must be understood from a developmental perspective. The hypothesis proposed in this paper is that such killings occur as the result of the adolescent's frustrated effort to progress along normative development. The goal of normative separation from maternal figures by the boy is presented as a potential risk factor when this goal is thwarted. Childhood case material from the perpetrator of a recent adolescent mass shooting, the Sandy Hook shooting, is discussed as an illustration of this hypothesis. Implications for public health measures and for individualized treatment are presented and developed.

  20. Tips for Good Electronic Presentations.

    Science.gov (United States)

    Strasser, Dennis

    1996-01-01

    Describes library uses of presentation graphics software and offers tips for creating electronic presentations. Tips include: audience retention; visual aid options; software package options; presentation planning; presentation showing; and use of text, colors, and graphics. Sidebars note common presentation errors and popular presentation…

  1. Germination, seedling growth and relative water content of shoot in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... (mg), root : shoot length (R:S) ratio, and relative water content of shoot (RWC, %) were investigated in this study. The results ... seedlings may provide an advantage by allowing access ... Residual chlorine was eliminated by.

  2. The effects of increased phosphorus application on shoot dry matter ...

    African Journals Online (AJOL)

    The effects of increased phosphorus application on shoot dry matter, shoot P and Zn concentrations in wheat ( Triticum durum L.) and maize ( Zea mays L.)wheat ( Triticum durum L.) and maize ( Zea mays L.) grown in a calcareous soil.

  3. Lethality Index 2008-2014: Less shootings, same lethality, more opacity

    Directory of Open Access Journals (Sweden)

    Carlos Silva Forné

    2017-11-01

    Full Text Available This article evaluates the use of lethal force by Mexican federal security forces during shootings with presumed members of organized crime from 2008-2014. The authors use official data and press reports on deaths and wounded in shootings to construct indicators such as the number of dead civilians over the number of dead officials from the federal security forces and the number of dead civilians over the number of wounded civilians. In a context where certain factors that contribute to an excessive use of force become more common, the results of the study show a growing use of lethal force. This raises questions over the possible excessive use of lethal force as a normal or systematic practice. The study also shows a growing context of opacity in the information available to evaluate the use of lethal force and the general lack of a legal framework to regulate the use of lethal force in Mexico.

  4. Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants

    DEFF Research Database (Denmark)

    Bastien, Renaud; Bohr, Tomas; Moulia, Bruno

    2012-01-01

    Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone...... is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies....

  5. Multiple shoot regeneration of cotton (Gossypium hirsutum L.) via ...

    African Journals Online (AJOL)

    user

    2011-03-14

    Mar 14, 2011 ... Induction of multiple shoots of cotton (Gossypium hirsutum L.) plant in two commercial varieties (Sahel and Varamin) using shoot apex was done. Explants were isolated from 3 - 4 days old seedlings, then they were cultured on a shoot induction media, modified MS nutrient agar with combinations: 1- ...

  6. Root~Shoot Growth Interactions of Sorghmn (Sorghwn Bicolor L ...

    African Journals Online (AJOL)

    growth. Studies on root-shoot intera'ctions in relation to mechanical impedance have only investigated the effect on shoots of ... growth regulators that may be responsible. Studies of root-shoot ... of germinating seeds to MI leaving roots in rela-.

  7. Sound propagation from a semi-open shooting range

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Berg, F. van den

    2011-01-01

    Semi-open shooting ranges, in contrast to a fully open shooting range, are often used in the densely populated area of the Netherlands. The Ministry of Defense operates a number of these ranges. In these shooting ranges above the line of fire a number of screens are situated for safety precautions

  8. Lead pollution of shooting range soils | Sehube | South African ...

    African Journals Online (AJOL)

    Atotal of eight military shooting ranges were used for this study. Soil samples were collected at each of the eight shooting ranges at the berm, target line, 50 and 100 m from berm. In all of the shooting ranges investigated the highest total lead (Pb) concentrations were found in the bermsoils. Elevated Pb concentrations of 38 ...

  9. Effects of calcium gluconate and ascorbic acid on controlling shoot ...

    African Journals Online (AJOL)

    In vitro shoot necrosis is a quite widespread disorder affecting raspberry micropropagation. This study was conducted to investigate effects of calcium gluconate and ascorbic acid on shoot necrosis and dieback of raspberry shoots during micropropagation. Nodal segments of primocane-fruiting raspberry cultivars 'Allgold', ...

  10. Shoot and root morphogenesis from Eucalyptus grandis x urophylla ...

    African Journals Online (AJOL)

    Eucalyptus grandis x urophylla plantlets were regenerated via indirect organogenesis. Histological assessment of their development focused on identifying the calli, the differentiation of shoots from the calli and the shoot-root junction from the nascent shoots. Vascular tissue formation within the callus preceded that of ...

  11. Protocol optimization for in vitro shoot multiplication of Jackfruit ...

    African Journals Online (AJOL)

    Jemal

    2017-01-11

    Jan 11, 2017 ... Protocol optimization for in vitro shoot multiplication of ... shoot length and leaf number, whereby 2 mg/L BAP alone was found to be the best with a mean shoot .... Analysis of variance showed that the interaction between.

  12. Regeneration of okra ( Abelmoschus esculentus L.) via apical shoot ...

    African Journals Online (AJOL)

    Abelmoschus esculentus L. Monech) via apical shoot culture system. The study of apical shoot culture system was found effective for regeneration of apical shoots. The okra (A. esculentus L. Monech) N-550 line evolved at R&D, Nirmal Seeds Pvt. Ltd., ...

  13. Plant regeneration from protoplasts ofVicia narbonensis via somatic embryogenesis and shoot organogenesis.

    Science.gov (United States)

    Tegeder, M; Kohn, H; Nibbe, M; Schieder, O; Pickardt, T

    1996-11-01

    Protoplasts ofVicia narbonensis isolated from epicotyls and shoot tips of etiolated seedlings were embedded in 1.4% sodium-alginate at a final density of 2.5×10(5) protoplasts/ml and cultivated in Kao and Michayluk-medium containing 0.5 mg/I of each of 2,4- dichlorophenoxyacetic acid, naphthylacetic acid and 6 -benzylaminopurine. A division frequency of 36% and a plating efficiency of 0.40-0.5% were obtained. Six weeks after embedding, protoplast-derived calluses were transferred onto gelrite-solidified Murashige and Skoog-media containing various growth regulators. Regeneration of plants was achieved via two morphologically distinguishable pathways. A two step protocol (initially on medium with a high auxin concentration followed by a culture phase with lowered auxin amount) was used to regenerate somatic embryos, whereas cultivation on medium containing thidiazuron and naphthylacetic acid resulted in shoot morphogenesis. Mature plants were recovered from both somatic embryos as well as from thidiazuron-induced shoots.

  14. Tree-shoot elongation patterns in a gamma-irradiated northern forest community

    International Nuclear Information System (INIS)

    Buech, R.R.; Salmonson, B.J.

    1977-01-01

    Shoot elongation in the upper crowns of seven tree species was studied in a gamma-irradiated northern forest community near Rhinelander, Wis. Observations on the pattern and duration of shoot elongation are presented for the irradiation (1972) and postirradiation (1973) growing seasons. The gymnosperm Abies balsamea was the most radiosensitive species. Significant alteration in pattern and duration was observed in 1973 at exposure rates of 4 to 25 r/20-hr day; 31 r/20-hr day was lethal. At the other extreme, 116 r/20-hr day produced no significant effects on Acer saccharum shoot elongation pattern or duration. Acer rubrum, Betula papyrifera, Populus tremuloides, Quercus rubra, and Tilia americana were intermediate in radiosensitivity. Observed responses to radiation were alteration in the elongation pattern, suppression of internodal elongation, and death. Effects of the 1972 growing-season exposure were most obvious in the subsequent growing seasons. Retardation of initial elongation was characteristic of all species. Cessation of elongation was variable, even within species (e.g., P. tremuloides). The results suggest that bud differentiation and morphology and dependency on food reserves contributed to the lag in manifestation of radiation damage. The resultant crown characteristics are described and explained

  15. At the Tipping Point

    Energy Technology Data Exchange (ETDEWEB)

    Wiley, H. S.

    2011-02-28

    There comes a time in every field of science when things suddenly change. While it might not be immediately apparent that things are different, a tipping point has occurred. Biology is now at such a point. The reason is the introduction of high-throughput genomics-based technologies. I am not talking about the consequences of the sequencing of the human genome (and every other genome within reach). The change is due to new technologies that generate an enormous amount of data about the molecular composition of cells. These include proteomics, transcriptional profiling by sequencing, and the ability to globally measure microRNAs and post-translational modifications of proteins. These mountains of digital data can be mapped to a common frame of reference: the organism’s genome. With the new high-throughput technologies, we can generate tens of thousands of data points from each sample. Data are now measured in terabytes and the time necessary to analyze data can now require years. Obviously, we can’t wait to interpret the data fully before the next experiment. In fact, we might never be able to even look at all of it, much less understand it. This volume of data requires sophisticated computational and statistical methods for its analysis and is forcing biologists to approach data interpretation as a collaborative venture.

  16. Tipping the scales.

    Science.gov (United States)

    1998-12-01

    In the US, the October 1998 murder of a physician who performed abortions was an outward manifestation of the insidious battle against legal abortion being waged by radical Christian social conservatives seeking to transform the US democracy into a theocracy. This movement has been documented in a publication entitled, "Tipping the Scales: The Christian Right's Legal Crusade Against Choice" produced as a result of a 4-year investigation conducted by The Center for Reproductive Law and Policy. This publication describes how these fundamentalists have used sophisticated legal, lobbying, and communication strategies to further their goals of challenging the separation of church and state, opposing family planning and sexuality education that is not based solely on abstinence, promoting school prayer, and restricting homosexual rights. The movement has resulted in the introduction of more than 300 anti-abortion bills in states, 50 of which have passed in 23 states. Most Christian fundamentalist groups provide free legal representation to abortion clinic terrorists, and some groups solicit women to bring specious malpractice claims against providers. Sophisticated legal tactics are used by these groups to remove the taint of extremism and mask the danger posed to US constitutional principles being posed by "a well-financed and zealous brand of radical lawyers and their supporters."

  17. Rosette growth of shoots in chrysanthemum (Dendranthema grandiflora Tzvelev) as a result of in vitro propagation of plants and gamma irradiation used for mutation induction

    International Nuclear Information System (INIS)

    Jerzy, M.; Zalewska, M.; Lema, J.

    1999-01-01

    Rosette growth of chrysanthemum shoots in 'Mrs. R.C. Puling' was observed after in vitro propagation with explants obtained from vernalised and non-vernalised stock plants. The phenomenon was also observed as a result of the exposure of leaf explants to gamma radiation used for in vitro regeneration of plants in mutation induction. The higher the irradiation dose, the more considerable the rosette growth. Following the 4th pinching of shoot tips, only elongating growth of plants was observed

  18. Multiple Shooting and Time Domain Decomposition Methods

    CERN Document Server

    Geiger, Michael; Körkel, Stefan; Rannacher, Rolf

    2015-01-01

    This book offers a comprehensive collection of the most advanced numerical techniques for the efficient and effective solution of simulation and optimization problems governed by systems of time-dependent differential equations. The contributions present various approaches to time domain decomposition, focusing on multiple shooting and parareal algorithms.  The range of topics covers theoretical analysis of the methods, as well as their algorithmic formulation and guidelines for practical implementation. Selected examples show that the discussed approaches are mandatory for the solution of challenging practical problems. The practicability and efficiency of the presented methods is illustrated by several case studies from fluid dynamics, data compression, image processing and computational biology, giving rise to possible new research topics.  This volume, resulting from the workshop Multiple Shooting and Time Domain Decomposition Methods, held in Heidelberg in May 2013, will be of great interest to applied...

  19. Date of shoot collection, genotype, and original shoot position affect early rooting of dormant hardwood cuttings of Populus

    Science.gov (United States)

    R. S., Jr. Zalesny; A.H. Wiese

    2006-01-01

    Identifying superior combinations among date of dormant- season shoot collection, genotype, and original shoot position can increase the rooting potential of Populus cuttings. Thus, the objectives of our study were to: 1) evaluate variation among clones in early rooting from hardwood cuttings processed every three weeks from shoots collected...

  20. Contagion in Mass Killings and School Shootings

    OpenAIRE

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    Background Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Methods Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent dat...

  1. Structuring agreements for seismic group shoots

    International Nuclear Information System (INIS)

    Keeping, C.E.

    1999-01-01

    Sigma Explorations Inc. sells licenses to use Sigma owned seismic data. The company participates with exploration and production companies in the joint acquisition of semi-private participation surveys. This paper discusses three major types of seismic group shoots and the essential elements of the agreements that govern or should govern them. They are: (1) exploration and production company joint ventures, (2) publicly offered spec shoots, and (3) semi-private participation surveys. The key issue with the exploration and production company joint ventures is that the companies are owners of the seismic data in proportion to their contribution towards the cost of the program. Their use of the data should be restricted to those situations permitted by the other owners. These are not often well documented, and there is much concern in the industry as a result. The key issue with publicly offered spec shoots is that the seismic company ultimately owns the data and the client exploration and production company is a licensee and must behave as such. In most such cases the rights and responsibilities are well documented in formal agreements that are signed in advance of the program's beginning date

  2. Effect of cytokinins on in vitro multiplication, volatiles composition and rosmarinic acid content of Thymus leucotrichus Hal. shoots.

    Science.gov (United States)

    Bekircan, Tuba; Yaşar, Ahmet; Yıldırım, Sercan; Sökmen, Münevver; Sökmen, Atalay

    2018-03-01

    An efficient in vitro multiplication protocol was designed to Thymus leucotrichus , a subshrub and perennial herb growing naturally in the Northwest of Turkey. Of all basal media studied, Murashige and Skoog medium was found to be superior to the others, providing higher shoot formation and the maximum shoot length. Varying concentrations of cytokinins, i.e., 6-benzyladenine, thidiazuron, 2-isopentenyladenine and kinetin were supplemented in the nutrient media to observe their effects on shoot development and biomass. Rosmarinic acid content and volatile compositions of both naturally growing plants and in vitro multiplied plantlets were also evaluated. 6-benzyladenine (1.0 mg/L) and kinetin (0.5 mg/L) were found to be optimum for shoot number and shoot elongation, respectively. Thidiazuron (1.0 mg/L) was superior for biomass production. Rosmarinic acid content of in vitro multiplied plants was found to be higher than that of wild plants, reaching a maximum with 0.5 mg/L 2-isopentenyladenine, which yielded 10.15 mg/g dry weight. The highest thymol content was obtained with 1.0 mg/L kinetin (55.82%), while thidiazuron (0.1 mg/L) increased carvacrol production (12.53%). Overall, Murashige and Skoog medium supplemented with 1.0 mg/L kinetin was determined to be the most favorable medium studied.

  3. Rampage shootings: an historical, empirical, and theoretical overview.

    Science.gov (United States)

    Rocque, Michael; Duwe, Grant

    2018-02-01

    Rampage shootings is a relatively new term to describe a phenomenon that has a long history. Rampage shootings are mass shootings (generally defined as involving four or more victims), taking place in a public location, with victims chosen randomly or for symbolic purposes. These shootings are isolated events, meaning they are not connected to another criminal act (such as robbery or terrorism). Research suggests that rampage shootings are not a new phenomenon, but have occurred throughout the US since the early 1900s. There is some evidence of an increase in recent years, but definitional differences across studies and data sources make interpreting trends somewhat tenuous. Theories regarding the perpetration of rampage shootings center on masculinity, mental illness, and contagion effects. Policies aimed at preventing rampage shootings remain somewhat controversial and not well-tested in the literature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... bleeding resistant to traditional medical treatments. The greatest difference in performing TIPS in children is their tremendous ...

  5. Fitness: Tips for Staying Motivated

    Science.gov (United States)

    Healthy Lifestyle Fitness Fitness is for life. Motivate yourself with these practical tips. By Mayo Clinic Staff Have ... 27, 2015 Original article: http://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/fitness/art-20047624 . Mayo Clinic ...

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... deeply you are sedated. When the needle is advanced through the liver and the pathway is expanded ... are the limitations of TIPS? Patients with more advanced liver disease are at greater risk for worsening ...

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... to determine the severity of the condition. To help plan for the placement of the TIPS stent, ... Radiological Society of North America, Inc. (RSNA). To help ensure current and accurate information, we do not ...

  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... avoiding the liver. TIPS may successfully reduce internal bleeding in the stomach and esophagus in patients with ... stomach, lower esophagus, and intestines, causing enlarged vessels, bleeding and the accumulation of fluid in the chest ...

  9. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... in the chest or abdomen. This condition is most commonly seen in adults, often as a result ... minimally invasive procedures such as a TIPS are most often performed by a specially trained interventional radiologist ...

  10. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... open. Patients who typically need a TIPS have portal hypertension , meaning they have increased pressure in the portal ... problems leading to cirrhosis (scarring of the liver). Portal hypertension can also occur in children, although children are ...

  11. Energy Savers: Cool Summer Tips

    International Nuclear Information System (INIS)

    Miller, M.

    2001-01-01

    A tri-fold brochure addressing energy-saving tips for homeowners ranging from low- or no-cost suggestions to higher cost suggestions for longer-term savings. Cooling, windows, weatherizing, and landscaping are addressed

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... complex and lengthy procedures requiring extended fluoroscopy use) death (rare) top of page What are the limitations ... filtered out by the liver. The TIPS may cause too much of these substances to bypass the ...

  13. Girlfriends' Health and Safety Tips

    Science.gov (United States)

    ... in Women? Women's Safety and Health Issues at Work Health Equity Girlfriends' Health and Safety Tips Recommend on Facebook Tweet Share Compartir Having friends is an important part of life. Celebrate female friendship and support your girlfriends by ...

  14. Search Tips: MedlinePlus

    Science.gov (United States)

    ... of this page: https://medlineplus.gov/searchtips.html Search Tips To use the sharing features on this page, please enable JavaScript. How do I search MedlinePlus? The search box appears at the top ...

  15. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, allergies and medications you’re taking. You ... with ascites or variceal bleeding resistant to traditional medical treatments. The greatest difference in performing TIPS in ...

  16. Computerized automatic tip scanning operation

    International Nuclear Information System (INIS)

    Nishikawa, K.; Fukushima, T.; Nakai, H.; Yanagisawa, A.

    1984-01-01

    In BWR nuclear power stations the Traversing Incore Probe (TIP) system is one of the most important components in reactor monitoring and control. In previous TIP systems, however, operators have suffered from the complexity of operation and long operation time required. The system presented in this paper realizes the automatic operation of the TIP system by monitoring and driving it with a process computer. This system significantly reduces the burden on customer operators and improves plant efficiency by simplifying the operating procedure, augmenting the accuracy of the measured data, and shortening operating time. The process computer is one of the PODIA (Plant Operation by Displayed Information Automation) systems. This computer transfers control signals to the TIP control panel, which in turn drives equipment by microprocessor control. The process computer contains such components as the CRT/KB unit, the printer plotter, the hard copier, and the message typers required for efficient man-machine communications. Its operation and interface properties are described

  17. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... the TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...

  18. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ...

  19. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... surgery. Your TIPS should have less of an effect than open surgical bypass on future liver transplantation ... Encephalopathy can be treated with certain medications, a special diet or, by revising the stent, but sometimes ...

  20. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ... limitations of TIPS? Patients with more advanced liver disease are at greater risk for worsening liver failure ...

  1. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... is completed. top of page What are the benefits vs. risks? Benefits A TIPS is designed to produce the same ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ...

  2. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... hepatic vein to identify the portal venous system. Access is then gained from the hepatic vein into ... TIPS procedure to make sure that it remains open and functions properly. top of page Who interprets ...

  3. Tips to Prevent Mosquito Bites

    Science.gov (United States)

    ... discourage mosquitoes, ticks and other biting insects from landing on you. Here are tips for other preventive ... CDC Mosquito Control Methods - NPIC Exit Top of Page Contact Us to ask a question, provide feedback, ...

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... while avoiding the liver. TIPS may successfully reduce internal bleeding in the stomach and esophagus in patients ... site. Using ultrasound, the doctor will identify your internal jugular vein , which is situated above your collarbone, ...

  5. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... and medical diseases. This can result in significant challenges in creating the TIPS. top of page Additional ... Please note RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical questions ...

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... the TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This ... here Images × Image Gallery Radiologist and patient consultation. View full size with caption Pediatric Content Some imaging ...

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Radiologist and patient consultation. View full size ... X-Ray and CT Exams Contrast Materials Venography Images related to Transjugular Intrahepatic Portosystemic Shunt (TIPS) Sponsored ...

  9. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... observed. This procedure is usually completed in an hour or two but may take up to several ...

  10. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... the portal system using a TIPS needle (a special long needle extending from the neck into the ... Encephalopathy can be treated with certain medications, a special diet or, by revising the stent, but sometimes ...

  11. (Allium cepa) root tip mitosis

    African Journals Online (AJOL)

    Aghomotsegin

    their chemical composition and genotoxic effects on cell reproduction. Two petrochemicals, air ... the chromosomes of the individual cells of the root tip could be a pointer to their ..... Chromosome technique: Theory and. Practice. Butterworths ...

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... Intrahepatic Portosystemic Shunt (TIPS)? What are some common uses of the procedure? How should I prepare? What does the equipment look like? How does the procedure work? How is the procedure performed? What will I ...

  13. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... in creating the TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient ... Send us your feedback Did you find the information you were looking for? Yes No Please type ...

  14. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... of bleeding that can occur can sometimes be life threatening and those patients are monitored in intensive ...

  15. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... blood draining from the bowel back to the heart while avoiding the liver. TIPS may successfully reduce ... blood away from the liver back to the heart). A stent is then placed in this tunnel ...

  16. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... portal vein to the hepatic vein in the liver. A small metal device called a stent is ... bowel back to the heart while avoiding the liver. TIPS may successfully reduce internal bleeding in the ...

  17. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose ...

  18. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... the liver. A small metal device called a stent is placed to keep the connection open and ... a small, tubular metal device commonly called a stent . During a TIPS procedure, interventional radiologists use image ...

  19. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... who typically need a TIPS have portal hypertension , meaning they have increased pressure in the portal vein ... the local anesthetic is injected. Most of the sensation is at the skin incision site, which is ...

  20. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... physician will numb an area just above your right collarbone with a local anesthetic . A very small ...

  1. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits A TIPS is designed to produce the ... skin that does not have to be stitched. Risks Any procedure where the skin is penetrated carries ...

  2. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... Patients who typically need a TIPS have portal hypertension , meaning they have increased pressure in the portal ... leading to cirrhosis (scarring of the liver). Portal hypertension can also occur in children, although children are ...

  3. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... above your collarbone, and guide a catheter, a long, thin, hollow plastic tube into the vessel. Using ...

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... This can result in significant challenges in creating the TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This page ...

  5. Tip model of cold fission

    International Nuclear Information System (INIS)

    Goennenwein, F.; Boersig, B.

    1991-01-01

    Cold fission is defined to be the limiting case of nuclear fission where virtually all of the available energy is converted into the total kinetic energy of the fragments. The fragments have, therefore, to be born in or at least close to their respective ground states. Starting from the viewpoint that cold fission corresponds to most compact scission configurations, energy constraints have been exploited to calculate minimum tip distances between the two nascent fragments in binary fission. Crucial input parameters to this tip model of cold fission are the ground-state deformations of fragment nuclei. It is shown that the minimum tip distances being compatible with energy conservation vary strongly with both the mass and charge fragmentation of the fission prone nucleus. The tip distances refer to nuclei with equivalent sharp surfaces. In keeping with the size of the surface width of leptodermous nuclei, only configurations where the tip distances are smaller than a few fm may be considered as valid scission configurations. From a comparison with experimental data on cold fission this critical tip distance appears to be 3.0 fm for the model parameters chosen. Whenever the model calculation yields tip distances being smaller than the critical value, a necessary condition for attaining cold fission is considered to be fulfilled. It is shown that this criterion allows to understand in fair agreement with experiment which mass fragmentations are susceptible to lead to cold fission and which fragment-charge divisions are the most favored in each isobaric mass chain. Being based merely on energy arguments, the model cannot aim at predicting fragment yields in cold fission. However, the tip model proposed appears well suited to delineate the phase space where cold fission phenomena may come into sight. (orig.)

  6. Short Linear Sequence Motif LxxPTPh Targets Diverse Proteins to Growing Microtubule Ends

    NARCIS (Netherlands)

    Kumar, Anil; Manatschal, Cristina; Rai, Ankit; Grigoriev, Ilya; Degen, Miriam Steiner; Jaussi, Rolf; Kretzschmar, Ines; Prota, Andrea E; Volkmer, Rudolf; Kammerer, Richard A.; Akhmanova, Anna; Steinmetz, Michel O.

    2017-01-01

    Microtubule plus-end tracking proteins (+TIPs) are involved in virtually all microtubule-based processes. End-binding (EB) proteins are considered master regulators of +TIP interaction networks, since they autonomously track growing microtubule ends and recruit a plethora of proteins to this

  7. Elimination of PPV and PNRSV through thermotherapy and meristem-tip culture in nectarine.

    Science.gov (United States)

    Manganaris, G A; Economou, A S; Boubourakas, I N; Katis, N I

    2003-10-01

    The plum pox virus (PPV) and prunus necrotic ringspot virus (PNRSV) cause serious disease problems in stone-fruit trees. In this work, the possibility of obtaining plant material free from these viruses through thermotherapy and meristem-tip culture from infected nectarine shoots (Prunus persica var. nectarina Max, cv. 'Arm King') was studied. In addition, the detection of these viruses in in vitro cultures and young acclimatized plantlets with double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) and multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) was studied. Meristem-tip explants (0.8-1.3 mm) derived from sprouted buds of winter wood and spring shoots from field grown plants had a 2-5% regeneration response. However, application of thermotherapy to potted nectarine trees (3 weeks at a maximum temperature of 35 degrees C) facilitated excision of longer meristem tips (1.3-2.0 mm) that resulted in a significantly higher regeneration response (38%) in woody plant medium (WPM) without plant growth regulators. Such explants formed multiple shoots with the addition of 8 microM benzylaminopurine and 0.8 microM indoleacetic acid. When they were tested for the presence of PPV and PNRSV, 86% and 81% were found to be virus-free as detected by DAS-ELISA and multiplex RT-PCR, respectively. Individual shoots excised from virus-free cultures readily rooted in vitro (half-strength WPM plus 2 microM indolebutyric acid) and grew to plantlets. The combination of an efficient protocol for virus elimination and the establishment of highly sensitive diagnostics resulted in the production of nectarine plants free from PPV and PNRSV.

  8. Effects of GhWUS from upland cotton (Gossypium hirsutum L.) on somatic embryogenesis and shoot regeneration.

    Science.gov (United States)

    Xiao, Yanqing; Chen, Yanli; Ding, Yanpeng; Wu, Jie; Wang, Peng; Yu, Ya; Wei, Xi; Wang, Ye; Zhang, Chaojun; Li, Fuguang; Ge, Xiaoyang

    2018-05-01

    The WUSCHEL (WUS) gene encodes a plant-specific homeodomain-containing transcriptional regulator, which plays important roles during embryogenesis, as well as in the formation of shoot and flower meristems. Here, we isolated two homologues of Arabidopsis thaliana WUS (AtWUS), GhWUS1a_At and GhWUS1b_At, from upland cotton (Gossypium hirsutum). Domain analysis suggested that the two putative GhWUS proteins contained a highly conserved DNA-binding HOX domain and a WUS-box. Expression profile analysis showed that GhWUSs were predominantly expressed during the embryoid stage. Ectopic expression of GhWUSs in Arabidopsis could induce somatic embryo and shoot formation from seedling root tips. Furthermore, in the absence of exogenous hormone, overexpression of GhWUSs in Arabidopsis could promote shoot regeneration from excised roots, and in the presence of exogenous auxin, excised roots expressing GhWUS could be induced to produce somatic embryo. In addition, expression of the chimeric GhWUS repressor in cotton callus inhibited embryogenic callus formation. Our results show that GhWUS is an important regulator of somatic embryogenesis and shoot regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Growth and artemisinin content of artemisia Annua L. As a result of gamma irradiation on shoot culture

    International Nuclear Information System (INIS)

    Tri Muji Ermayanti; Erwin Al Hafiizh; Andri Fadillah Martin; Arthur A Lelono; Wiguna Rahman

    2016-01-01

    Artemisinin is the main compound produced by Artemisia annua is used as antimalarial drug. Many research have been conducted in order to increase artemisinin content in A. annua so that it can be produced economically. In several plants, mutation can be induced by Gamma irradiation to increase their secondary metabolite production. The aim of this research was to investigate the growth and artemisinin content of A. annua after Gamma irradiation. Irradiation was conducted using in vitro shoot tips with 5-50 Gy. Survival rate, growth of shoot culture, ploidy level confirmation, acclimatization, growth of plants in the field and artemisinin content were recorded. The results showed that LD_5_0 of A. annua was 37 Gy, therefore, shoots only grew in the control environment in the laboratory, their growth in the field was inhibited. Irradiation with 50 Gy, shoots only grew for 8 weeks, and died afterwards. Irradiation dose affected on growth of plants in the field as well as their artemisinin content. (author)

  10. Mechanically, the shoot apical meristem of Arabidopsis behaves like a shell inflated by a pressure of about 1 MPa

    Directory of Open Access Journals (Sweden)

    Léna eBeauzamy

    2015-11-01

    Full Text Available In plants, the shoot apical meristem contains the stem cells and is responsible for the generation of all aerial organs. Mechanistically, organogenesis is associated with an auxin-dependent local softening of the epidermis. This has been proposed to be sufficient to trigger outgrowth, because the epidermis is thought to be under tension and stiffer than internal tissues in all the aerial part of the plant. However, this has not been directly demonstrated in the shoot apical meristem. Here we tested this hypothesis in Arabidopsis using indentation methods and modeling. We considered two possible scenarios: either the epidermis does not have unique properties and the meristem behaves as a homogeneous linearly-elastic tissue, or the epidermis is under tension and the meristem exhibits the response of a shell under pressure. Large indentation depths measurements with a large tip (~size of the meristem were consistent with a shell-like behavior. This also allowed us to deduce a value of turgor pressure, estimated at 0.82 ± 0.16 MPa. Indentation with atomic force microscopy provided local measurements of pressure in the epidermis, further confirming the values obtained from large deformations. Altogether, our data demonstrate that the Arabidopsis shoot apical meristem behaves like a shell under a MPa range pressure and support a key role for the epidermis in shaping the shoot apex.

  11. Magnetic field measurements using the transient internal probe (TIP)

    International Nuclear Information System (INIS)

    Galambos, J.P.; Bohnet, M.A.; Jarboe, T.R.; Mattick, A.T.

    1995-01-01

    Knowledge of the internal magnetic field profile in hot plasmas is fundamental to understanding the structure and behavior of the current profile. The transient internal probe (TIP) is a novel diagnostic designed to measure internal magnetic fields in hot plasmas. The diagnostic involves shooting a magneto-optic probe through the plasma at high velocities (greater than 2 km/s) using a two stage light gas gun. Local fields are obtained by illuminating the probe with an argon ion laser and measuring the amount of Faraday rotation in the reflected beam. Initial development of the diagnostic is complete. Results of magnetic field measurements conducted at 2 km/s will be presented. Helium muzzle gas introduction to the plasma chamber has been limited to less than 0.4 Torr-ell. Magnetic field resolution of 40 Gauss and spatial resolution of 5 mm have been achieved. System frequency response is 10 MHz

  12. Proteomic analysis of shoot tissue during photoperiod induced growth cessation in V. riparia Michx. grapevines

    Directory of Open Access Journals (Sweden)

    Victor Kim J

    2010-08-01

    Full Text Available Abstract Background Growth cessation, cold acclimation and dormancy induction in grapevines and other woody perennial plants native to temperate continental climates is frequently triggered by short photoperiods. The early induction of these processes by photoperiod promotes winter survival of grapevines in cold temperate zones. Examining the molecular processes, in particular the proteomic changes in the shoot, will provide greater insight into the signaling cascade that initiates growth cessation and dormancy induction. To begin understanding transduction of the photoperiod signal, Vitis riparia Michx. grapevines that had grown for 35 days in long photoperiod (long day, LD, 15 h were subjected to either a continued LD or a short photoperiod (short day, SD, 13 h treatment. Shoot tips (4-node shoot terminals were collected from each treatment at 7 and 28 days of LD and SD for proteomic analysis via two-dimensional (2D gel electrophoresis. Results Protein profiles were characterized in V. riparia shoot tips during active growth or SD induced growth cessation to examine physiological alterations in response to differential photoperiod treatments. A total of 1054 protein spots were present on the 2D gels. Among the 1054 proteins, 216 showed differential abundance between LD and SD (≥ two-fold ratio, p-value ≤ 0.05. After 7 days, 39 protein spots were more abundant in LD and 30 were more abundant in SD. After 28 days, 93 protein spots were more abundant in LD and 54 were more abundant in SD. MS/MS spectrometry was performed to determine the functions of the differentially abundant proteins. Conclusions The proteomics analysis uncovered a portion of the signal transduction involved in V. riparia grapevine growth cessation and dormancy induction. Different enzymes of the Calvin-Benson cycle and glutamate synthetase isoforms were more abundant either in LD or SD treatments. In LD tissues the significantly differentially more abundant proteins

  13. Proteomic analysis of shoot tissue during photoperiod induced growth cessation in V. riparia Michx. grapevines

    Science.gov (United States)

    2010-01-01

    Background Growth cessation, cold acclimation and dormancy induction in grapevines and other woody perennial plants native to temperate continental climates is frequently triggered by short photoperiods. The early induction of these processes by photoperiod promotes winter survival of grapevines in cold temperate zones. Examining the molecular processes, in particular the proteomic changes in the shoot, will provide greater insight into the signaling cascade that initiates growth cessation and dormancy induction. To begin understanding transduction of the photoperiod signal, Vitis riparia Michx. grapevines that had grown for 35 days in long photoperiod (long day, LD, 15 h) were subjected to either a continued LD or a short photoperiod (short day, SD, 13 h) treatment. Shoot tips (4-node shoot terminals) were collected from each treatment at 7 and 28 days of LD and SD for proteomic analysis via two-dimensional (2D) gel electrophoresis. Results Protein profiles were characterized in V. riparia shoot tips during active growth or SD induced growth cessation to examine physiological alterations in response to differential photoperiod treatments. A total of 1054 protein spots were present on the 2D gels. Among the 1054 proteins, 216 showed differential abundance between LD and SD (≥ two-fold ratio, p-value ≤ 0.05). After 7 days, 39 protein spots were more abundant in LD and 30 were more abundant in SD. After 28 days, 93 protein spots were more abundant in LD and 54 were more abundant in SD. MS/MS spectrometry was performed to determine the functions of the differentially abundant proteins. Conclusions The proteomics analysis uncovered a portion of the signal transduction involved in V. riparia grapevine growth cessation and dormancy induction. Different enzymes of the Calvin-Benson cycle and glutamate synthetase isoforms were more abundant either in LD or SD treatments. In LD tissues the significantly differentially more abundant proteins included flavonoid

  14. Light Requirement for Shoot Regeneration in Horseradish Hairy Roots 1

    Science.gov (United States)

    Saitou, Tsutomu; Kamada, Hiroshi; Harada, Hiroshi

    1992-01-01

    Hairy roots of horseradish (Armoracia rusticana) were induced by inoculation with Agrobacterium rhizogenes harboring Ri plasmid and cultured on phytohormone-free Murashige and Skoog medium after eliminating the bacteria. Hairy roots grew vigorously and sometimes formed yellowish calli under dark conditions. On the other hand, growth of hairy roots stopped after several weeks of culture with light, then shoots were regenerated. Frequency of shoot formation from hairy roots increased as the culture period in light lengthened and the light intensity increased. The shoot regeneration was induced by treatment with white or red light, but not with far-red light. Shoot regeneration by red light was inhibited by following treatment with far-red light. Red and far-red light reversibly affected shoot regeneration. Excised roots of nontransformed plants grew quite slowly on phytohormone-free Murashige and Skoog medium and occasionally formed shoots under white light conditions. PMID:16669041

  15. Light requirement for shoot regeneration in horseradish hairy roots.

    Science.gov (United States)

    Saitou, T; Kamada, H; Harada, H

    1992-08-01

    Hairy roots of horseradish (Armoracia rusticana) were induced by inoculation with Agrobacterium rhizogenes harboring Ri plasmid and cultured on phytohormone-free Murashige and Skoog medium after eliminating the bacteria. Hairy roots grew vigorously and sometimes formed yellowish calli under dark conditions. On the other hand, growth of hairy roots stopped after several weeks of culture with light, then shoots were regenerated. Frequency of shoot formation from hairy roots increased as the culture period in light lengthened and the light intensity increased. The shoot regeneration was induced by treatment with white or red light, but not with far-red light. Shoot regeneration by red light was inhibited by following treatment with far-red light. Red and far-red light reversibly affected shoot regeneration. Excised roots of nontransformed plants grew quite slowly on phytohormone-free Murashige and Skoog medium and occasionally formed shoots under white light conditions.

  16. Accuracy of Skill Performance in the Basketball Free Throw Shooting

    Directory of Open Access Journals (Sweden)

    Igawa Shoji

    2011-12-01

    Full Text Available The purpose of this study were to investigates how timing of shot of skilled player and assess performance accuracy of free throw shooting. Ten college students participated in this study (5 skilled players, and 5 naïve participants aged 18-23 years. They performed free throw shooting at 10 times. Shooting seen was recorded three cameras and analyzed shooting successful rate, off-target distance (the distance between the basketball through point and the center of the goal and shot timing. Shot timing was not significant difference. Shooting successful rate of skilled players was higher than unskilled players. Offtarget distance of skilled players was significant smaller than naive player. Consequently, skilled player is possible to aim at the center of the goal and shooting near the center of goal.

  17. Youth Responses to School Shootings: a Review.

    Science.gov (United States)

    Travers, Áine; McDonagh, Tracey; Elklit, Ask

    2018-05-19

    This paper aims to synthesize research relating to youth responses to school shootings between 2014 and 2017. The main questions it addresses are how such events impact young people psychologically, and what risk or protective factors may contribute to different trajectories of recovery? Recent research suggests that most young people exposed to school shootings demonstrate resilience, exhibiting no long-term dysfunction. However, a minority will experience severe and chronic symptoms. The likelihood of experiencing clinically significant reactions is influenced by pre-trauma functioning as well as peri-traumatic and post-traumatic factors. These include proximity to the trauma, peri-traumatic dissociation, post-traumatic emotional regulation difficulties, social support, and flexibility of coping styles. Research that separates the distinguishing features of young people with differing recovery styles is vital to tailor intervention. But methodological and design issues associated with such research necessitates caution in drawing conclusions. Variation in definitions and measures and the self-report nature of many of the studies are potential sources of bias. Greater uniformity across designs would enhance confidence and allow for improved evidence-based intervention.

  18. Effects of N6-benzylaminopurine and Indole Acetic Acid on In Vitro Shoot Multiplication, Nodule-like Meristem Proliferation and Plant Regeneration of Malaysian Bananas (Musa spp.)

    Science.gov (United States)

    Sipen, Philip; Davey, Michael R

    2012-01-01

    Different concentrations of N6-benzylaminopurine (BAP) and indole acetic acid (IAA) in Murashige and Skoog based medium were assessed for their effects on shoot multiplication, nodule-like meristem proliferation and plant regeneration of the Malaysian banana cultivars Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak. BAP at 1–14 mg L−1 with or without 0.2 mg L−1 IAA, or BAP at 7–14 mg L−1 with the same concentration of IAA, was evaluated for shoot multiplication from shoot tips and the proliferation of nodule-like meristems from scalps, respectively. Plant regeneration from scalps was assessed using 1 mg L−1 BAP and 0.2 mg L−1 IAA separately, or a combination of these two growth regulators. Data on shoot multiplication, the proliferation of nodule-like meristems with associated plant regeneration were recorded after 30 days of culture. A maximum of 5 shoots per original shoot tip was achieved on medium supplemented with BAP at 5 mg L−1 (Pisang Nangka), 6 mg L−1 (Pisang Mas and Pisang Berangan), or 7 mg L−1 (Pisang Awak), with 0.2 mg L−1 IAA. BAP at 11 mg L−1 with 0.2 mg L−1 IAA induced the most highly proliferating nodule-like meristems in the four banana cultivars. Plant regeneration from scalps was optimum in all cases on medium containing 1 mg L−1 BAP and 0.2 mg L−1 IAA. This is the first report on the successful induction of highly proliferating nodule-like meristems and plant regeneration from scalps of the Malaysian banana cultivars Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak. PMID:24575235

  19. Journalism and School Shootings in Finland 2007 -2008

    OpenAIRE

    Raittila, Pentti; Koljonen, Kari; Väliverronen, Jari

    2010-01-01

    Two school shootings in Finland (Jokela in 2007 and Kauhajoki in 2008) resulted in the death of 20 people, and they shook not only the foundations of Finnish society but also of the profession that reported about the tragedies. This report is based on research conducted on school shootings at the University of Tampere Journalism Research and Development Centre between 2008 and 2009. The analysis concentrates on both the journalistic texts published on the shootings and journalists' actions...

  20. Root tips moving through soil

    Science.gov (United States)

    Curlango-Rivera, Gilberto

    2011-01-01

    Root elongation occurs by the generation of new cells from meristematic tissue within the apical 1–2 mm region of root tips. Therefore penetration of the soil environment is carried out by newly synthesized plant tissue, whose cells are inherently vulnerable to invasion by pathogens. This conundrum, on its face, would seem to reflect an intolerable risk to the successful establishment of root systems needed for plant life. Yet root tip regions housing the meristematic tissues repeatedly have been found to be free of microbial infection and colonization. Even when spore germination, chemotaxis, and/or growth of pathogens are stimulated by signals from the root tip, the underlying root tissue can escape invasion. Recent insights into the functions of root border cells, and the regulation of their production by transient exposure to external signals, may shed light on long-standing observations. PMID:21455030

  1. Crack tip stress and strain

    International Nuclear Information System (INIS)

    Francois, D.

    1975-01-01

    The study of potential energy variations in a loaded elastic solid containing a crack leads to determination of the crack driving force G. Generalization of this concept to cases other than linear elasticity leads to definition of the integral J. In a linear solid, the crack tip stress field is characterized by a single parameter: the stress-intensity factor K. When the crack tip plastic zone size is confined to the elastic singularity J=G, it is possible to establish relationship between these parameters and plastic strain (and in particular the crack tip opening displacement delta). The stress increases because of the triaxiality effect. This overload rises with increasing strain hardening. When the plastic zone size expands, using certain hypotheses, delta can be calculated. The plastic strain intensity is exclusively dependent on parameter J [fr

  2. Optical fiber meta-tips

    Science.gov (United States)

    Principe, Maria; Micco, Alberto; Crescitelli, Alessio; Castaldi, Giuseppe; Consales, Marco; Esposito, Emanuela; La Ferrara, Vera; Galdi, Vincenzo; Cusano, Andrea

    2016-04-01

    We report on the first example of a "meta-tip" configuration that integrates a metasurface on the tip of an optical fiber. Our proposed design is based on an inverted-Babinet plasmonic metasurface obtained by patterning (via focused ion beam) a thin gold film deposited on the tip of an optical fiber, so as to realize an array of rectangular aperture nanoantennas with spatially modulated sizes. By properly tuning the resonances of the aperture nanoantennas, abrupt variations can be impressed in the field wavefront and polarization. We fabricated and characterized several proof-of-principle prototypes operating an near-infrared wavelengths, and implementing the beam-steering (with various angles) of the cross-polarized component, as well as the excitation of surface waves. Our results pave the way to the integration of the exceptional field-manipulation capabilities enabled by metasurfaces with the versatility and ubiquity of fiber-optics technological platforms.

  3. Mass propagation of shoots of Stevia rebaudiana using a large scale bioreactor.

    Science.gov (United States)

    Akita, M; Shigeoka, T; Koizumi, Y; Kawamura, M

    1994-01-01

    A procedure for the mass propagation of multiple shoots of Stevia rebaudiana is described. Isolated shoot primordia were used as the inoculum to obtain clusters of shoot primordia. Such clusters were grown in a 500 liter bioreactor to obtain shoots. A total of 64.6 Kg of shoots were propagated from 460 g of the inoculated shoot primordia. These shoots were easily acclimatized in soil.

  4. Australian Mass Shootings: An Analysis of Incidents and Offenders.

    Science.gov (United States)

    McPhedran, Samara

    2017-06-01

    Mass shooting events are relatively underresearched, and most study comes from the United States. Despite significant international interest, little is known about other countries' experiences of these events. The current study examines Australian mass shooting incidents and offenders, with emphasis on mental illness, life strains, and offenders' life histories. Australia had 14 mass shootings between 1964 and 2014. Most offenders experienced acute life stressors and/or chronic strains leading up to the event; however, diagnosed mental illness was less commonly documented. These observations provide new information about mass shooting incidents and offenders, and can help to inform international policy development.

  5. School shootings: law enforcement and school district networking

    OpenAIRE

    Topadzhikyan, Tigran

    2013-01-01

    CHDS State/Local School shootings have happened in the past and will happen again. The history of school shootings prompts all stakeholders to look at ways to prevent them from happening, and if they do happen, to be resilient. Change is needed in the prevention of school shootings. The case studies of Virginia Tech, Sandy Hook, E. O. Green Junior High, and Beslan school shootings reveal that the lack of information sharing and lack of communication were flaws; and the incidents might have...

  6. In vitro mass propagation of Salvia canariensis by axillary shoots

    Directory of Open Access Journals (Sweden)

    Sebastiana Mederos Molina

    2014-01-01

    Full Text Available During the establishment of shoots of Salvia canariensis L., five environmental factor treatments were applied. For each axillary node two shoots grew well when explants were incubated at continued ligth for 15 days followed by 16 hrs photoperiod by 30 days. Shoots multiplication was improved on a modified Murashige and Skoog (MS (1962 medium - MS + 825 mg/l NH4NO3 - supplemented with 10-7 M BA and 10-7 M NAA. The shoots produced well developed root systems within three weeks after transfer to the same culture medium supplemented with 5x 10-7 M NAA.

  7. ZBrush Professional Tips and Techniques

    CERN Document Server

    Gaboury, Paul

    2012-01-01

    Learn to work effectively and creatively with all versions of ZBrush! ZBrush is used by top artists in Hollywood to model and sculpt characters in such films as Avatar, Iron Man, and Pirates of the Caribbean. In addition, this amazing technology is also used in jewelry design, forensic science, aerospace, video games, toy creation, and the medical field. Written by Pixologic's in-house ZBrush expert Paul Gaboury, this full-color, beautifully illustrated guide provides you with the ultimate tips and tricks to maximize your use of all versions of ZBrush. Reveals numerous little-known tips and tr

  8. SHOOT2.0: An indirect grid shooting package for optimal control problems, with switching handling and embedded continuation

    OpenAIRE

    Martinon , Pierre; Gergaud , Joseph

    2010-01-01

    The SHOOT2.0 package implements an indirect shooting method for optimal control problems. It is specifically designed to handle control discontinuities, with an automatic switching detection that requires no assumptions concerning the number of switchings. Special care is also devoted to the computation of the Jacobian matrix of the shooting function, using the variational system instead of classical finite differences. The package also features an embedded continuation method and an automati...

  9. The genetic architecture of shoot-root covariation during seedling emergence of a desert tree, Populus euphratica.

    Science.gov (United States)

    Zhang, Miaomiao; Bo, Wenhao; Xu, Fang; Li, Huan; Ye, Meixia; Jiang, Libo; Shi, Chaozhong; Fu, Yaru; Zhao, Guomiao; Huang, Yuejiao; Gosik, Kirk; Liang, Dan; Wu, Rongling

    2017-06-01

    The coordination of shoots and roots is critical for plants to adapt to changing environments by fine-tuning energy production in leaves and the availability of water and nutrients from roots. To understand the genetic architecture of how these two organs covary during developmental ontogeny, we conducted a mapping experiment using Euphrates poplar (Populus euphratica), a so-called hero tree able to grow in the desert. We geminated intraspecific F 1 seeds of Euphrates Poplar individually in a tube to obtain a total of 370 seedlings, whose shoot and taproot lengths were measured repeatedly during the early stage of growth. By fitting a growth equation, we estimated asymptotic growth, relative growth rate, the timing of inflection point and duration of linear growth for both shoot and taproot growth. Treating these heterochronic parameters as phenotypes, a univariate mapping model detected 19 heterochronic quantitative trait loci (hQTLs), of which 15 mediate the forms of shoot growth and four mediate taproot growth. A bivariate mapping model identified 11 pleiotropic hQTLs that determine the covariation of shoot and taproot growth. Most QTLs detected reside within the region of candidate genes with various functions, thus confirming their roles in the biochemical processes underlying plant growth. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  10. Patterns of radial and shoot growth of five tree species in a gamma-irradiated northern Wisconsin forest

    International Nuclear Information System (INIS)

    Zavitkovski, J.; Buech, R.R.; Rudolph, T.D.; Bauer, E.O.

    1977-01-01

    Patterns of radial and shoot growth of Abies balsamea, Acer rubrum, A. saccharum, Betula papyrifera, and Populus tremuloides were observed before (1970) and during (1972) gamma-irradiation of forest communities in the Enterprise Radiation Forest. Measurements were made during the growing season along the radiation gradient, and year days (YD) of 10, 25, 50, 75, and 90 percent of total growth were obtained by interpolation. The experimental area was divided into an ''affected'' and a ''no-effect'' zone. The boundary of the affected zone coincided with radiation exposures that effectively reduced the 1972 radial growth of a given species in comparison to the preirradiation growth. In 1970 and in the no-effect zone in 1972, shoot growth of the four broadleaved species started and terminated earlier than the radial growth. In A. balsamea the radial growth started earlier and terminated later than the shoot growth. In all five species, duration of radial growth was significantly longer than that of shoot growth. Radial growth of A. rubrum, A. saccharum, and B. papyrifera started significantly earlier in 1972 than in 1970, but no difference between years was found in the early-starting A. balsamea and P. tremuloides. In contrast, shoot growth of all five species started earlier in 1970 than in 1972. It is suggested that temperature regimes during the early developmental stages were probably responsible for the difference. In the affected zone in 1972, the radiation depressed radial growth and changed its normal pattern in all five species

  11. Gibberellins in shoots and developing capsules of Populus species.

    Science.gov (United States)

    Pearce, David W; Hutt, Oliver E; Rood, Stewart B; Mander, Lewis N

    2002-03-01

    Extracts of stems of growing shoots of Populus deltoides and P. trichocarpa, and developing capsules of P. deltoides were analysed for gibberellins (GAs) by gas chromatography-mass spectrometry. The following known GAs were identified by comparison of their Kovats retention indices (KRIs) and mass spectra with those of standards: GA1, GA8, GA9, GA19, GA20, 16 beta,17-dihydro-17-hydroxy GA20, GA23, GA28, GA29, GA34, GA44, and GA97. Several of these have not been previously reported from Populus. In addition, two new GAs were identified as 12 beta-hydroxy GA53 (GA127) and 16 beta,17-dihydro-17-hydroxy GA53 and their structures were confirmed by partial synthesis. Evidence was found of 16,17-dihydro-16,17-dihydroxy GA9, 16,17-dihydro-16,17-dihydroxy GA12, 12-hydroxy GA14, and GA34-catabolite by comparison of mass spectra and KRIs with published data. Several putative GAs (hydroxy- and dihydroxy-GA12-like) were also found. The catabolites of active GAs or of key precursors, hydroxylated at C-2 in stems and either C-2, C-12, C-17, or C-16,17 in capsules, were the major proportion of the GAs.

  12. Growing Safflower in Utah

    OpenAIRE

    Pace, M. G.; Israelsen, C. E.; Creech, E.; Allen, N.

    2015-01-01

    This fact sheet provides information on growing safflower in Utah. It has become popular on dryland farms in rotation with winter wheat. Safflower seed provides three products, oil, meal, and birdseed.

  13. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of TIPS? ...

  14. Nanobits: customizable scanning probe tips

    DEFF Research Database (Denmark)

    Kumar, Rajendra; Shaik, Hassan Uddin; Sardan Sukas, Özlem

    2009-01-01

    We present here a proof-of-principle study of scanning probe tips defined by planar nanolithography and integrated with AFM probes using nanomanipulation. The so-called 'nanobits' are 2-4 mu m long and 120-150 nm thin flakes of Si3N4 or SiO2, fabricated by electron beam lithography and standard s...

  15. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... thin, hollow plastic tube into the vessel. Using real time x-ray guidance, your doctor will then guide ... invasive procedure that typically has a shorter recovery time than surgery. Your TIPS should have less of an effect ...

  16. The tip of the iceberg

    DEFF Research Database (Denmark)

    Bjørst, Lill Rastad

    2010-01-01

      Abstract: The tip of the iceberg: Ice as a nonhuman actor of the climate change debate   The global climate change debate has the Arctic as a core region of concern and ice has become a central aspect of discourses. This article discusses ice representations from six different contexts linked...

  17. Gardening Health and Safety Tips

    Science.gov (United States)

    ... or who take certain medications (i.e. for depression, insomnia, or poor circulation). Eat healthy foods to help keep you energized. Extreme Heat Keep Your Cool in Hot Weather Tips for persons with disabilities and physical activity. Talk to your health care provider if you have physical, mental, or ...

  18. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... Portosystemic Shunt (TIPS) Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ... links: For the convenience of our users, RadiologyInfo .org provides links to relevant websites. RadiologyInfo.org , ACR ...

  19. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... in creating the TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This page ... of Use | Links | Site Map Copyright © 2018 ... To help ensure current and accurate information, we do not permit copying but encourage linking ...

  20. Useful Tips on Avoiding Plagiarism

    Science.gov (United States)

    Hamalainen, Maryellen

    2007-01-01

    Teachers are generally kind and nurturing people. Students who plagiarize their assignments from these kind and nurturing teachers are often given a second chance when caught and encouraged to do their work over, but it would be better to eliminate their need to plagiarize. The first tip for eliminating plagiarism has not so much to do with what…

  1. Assigning Effective Homework. Classroom Tips

    Science.gov (United States)

    American Federation of Teachers (NJ), 2010

    2010-01-01

    Each new school year brings high hopes, great expectations and challenges for both new and seasoned educators. The American Federation of Teachers (AFT) has developed a series called "Classroom Tips" to help educators start the year right and anticipate the year ahead. Over the past 40 years, most research studies on homework have found that…

  2. Influence of Soil Based Growing Media on Vegetative Propagation of Selected Cultivars of Olea Europaea

    International Nuclear Information System (INIS)

    Ahmed, M. I.; Ashraf, M. I.; Malik, S. U.; Husaain, Q.

    2016-01-01

    Pothwar region of Pakistan is a natural habitat of Olea spp. There is a high demand of certified olive plants to establish olive orchids in the region, because native wild species are non-fruit bearing. Plants of certified fruit bearing olive (Olea europaea L.) cultivars are rarely available. Vegetative propagation of olive is highly responsive to texture of soil based growing media. This study examined the effect of growing media composition (soil texture and nutrients) on vegetative propagation of five cultivars of olive. The experiment was carried out in randomized complete block design (RCBD) with two factors factorial having 25 repeats of each four treatments. Plant growth and survival data were collected and analyzed for the influence of soil attributes. In sandy loam soil, cv. Bari-1 had 82 percent plant survival, highest number of roots per plant (3.5), and longest root length (13.01 cm). Highest number of shoots per plant (4.25) and maximum shoot length (15.64 cm) were also recorded for Bari-1 with sandy loam growing media. Silt loam soil is least suitable growing media for vegetative propagation of olive. In the silt loam soil, plants survival rate was 59 percent for cv. Gemlik, number of roots per plant was 1.5 for cv. Ottobrattica, minimum root length 5.65 cm, minimum number of shoots per plant one, and minimum shoot length 7.42 cm were recorded for cv. Pendolino with silt loam soil. Results suggested that sandy loam growing media is better than the others for vegetative propagation of olive. Cultivar Bari-1 performed better than the others examined in this study by indicating highest (1) survival percentage, (2) root and shoot length, and (3) number of roots and shoots produced within a specific period of time. (author)

  3. Analysis of sports injuries related with shooting.

    Science.gov (United States)

    Kabak, Banu; Karanfilci, Muharrem; Ersöz, Taner; Kabak, Mehmet

    2016-06-01

    Athletes typically maintain rigorous training and work programs to be able to participate in competitions. An injury that occurs during the competition that causes withdrawal from the competition and a possible departure from sports, can render results athletes' and their support staff's efforts as meaningless. The early detection of injuries in the competition and developing preventive training programs can help ensure that participating in competitions and the associated preparatory efforts are not wasted. In this study, the sports injuries discussed occurred during training and competition events of the Turkish Shooting Sportive group. Body parts of injuries are determined and exercise programs focused on the affected body parts are developed. A total of 729 athletes (285 female, 444 male) who participated in Turkish Shooting Sports Championship during the 2010-2011 competition period participated in the study. Athletes were given a questionnaire that was developed prior to the event, and the questionnaire was filled in during interviews conducted one-on-one. Data was collected from the questionnaire and SPSS v.16.0 was used to analyze the results. The study was completed in six months. The results showed that the most of the injuries that occurred during training were strain and muscle tears whereas most of the injuries occurred during the actual competition were strain, muscle tears, tendinitis, and sprain. The results also indicated that during training, the most frequently-occurring injuries were in shoulder, calf-thigh, hand and wrist; whereas during the competition, it was manifested in the shoulder, foot and ankle. Muscle strengthening, stretching and proprioception exercises for these body parts should be included as part of the athletic training program.

  4. Ion Frequency Landscape in Growing Plants.

    Directory of Open Access Journals (Sweden)

    Mariusz Pietruszka

    Full Text Available It has been interesting that nearly all of the ion activities that have been analysed thus far have exhibited oscillations that are tightly coupled to growth. Here, we present discrete Fourier transform (DFT spectra with a finite sampling of tip-growing cells and organs that were obtained from voltage measurements of the elongating coleoptiles of maize in situ. The electromotive force (EMF oscillations (~ 0.1 μV were measured in a simple but highly sensitive resistor-inductor circuit (RL circuit, in which the solenoid was initially placed at the tip of the specimen and then was moved thus changing its position in relation to growth (EMF can be measured first at the tip, then at the sub-apical part and finally at the shank. The influx- and efflux-induced oscillations of Ca2+, along with H+, K+ and Cl- were densely sampled (preserving the Nyquist theorem in order to 'grasp the structure' of the pulse, the logarithmic amplitude of pulse spectrum was calculated, and the detected frequencies, which displayed a periodic sequence of pulses, were compared with the literature data. A band of life vital individual pulses was obtained in a single run of the experiment, which not only allowed the fundamental frequencies (and intensities of the processes to be determined but also permitted the phase relations of the various transport processes in the plasma membrane and tonoplast to be established. A discrete (quantised frequency spectrum was achieved for a growing plant for the first time, while all of the metabolic and enzymatic functions of the life cell cycle were preserved using this totally non-invasive treatment.

  5. Highly efficient in vitro adventitious shoot regeneration of Adenosma ...

    African Journals Online (AJOL)

    Adenosma glutinosum (Linn.) Druce is an important aromatic plant, but no information is available regarding its regeneration, callus induction and proliferation from leaf explants. In this study, an in vitro shoot regeneration procedure was developed for native A. glutinosum using leaf explants. Callus induction and shoots ...

  6. Defense.gov Special Report: Fort Hood Shooting

    Science.gov (United States)

    identify possible insider threats, Army Secretary John M. McHugh told lawmakers. Story Obama: Soldiers ," Army Secretary John M. McHugh told lawmakers. Story President Praises Swift Response to Fort Hood Remarks on Fort Hood Shooting at White House McHugh, Odierno Address Fort Hood Shooting Before Congress

  7. An Analysis of US School Shooting Data (1840-2015)

    Science.gov (United States)

    Paradice, David

    2017-01-01

    This paper describes the construction and descriptive analysis of a data set of United States school shooting events. Three hundred forty-three shooting events are included, spanning 175 years of United States educational history. All levels of US educational institution are included. Events are included when a firearm is discharged, regardless of…

  8. How to talk (and not to talk) about school shootings

    OpenAIRE

    Scheper-Hughes, N

    2018-01-01

    © RAI 2018 In this guest editorial, the author addresses the latest school shootings at the Marjory Stoneman Douglas High School in Parkland, Florida. This event is weighed up against reports written by prominent academics, including anthropologists, during previous school shootings.

  9. Revisiting the Virginia Tech Shootings: An Ecological Systems Analysis

    Science.gov (United States)

    Hong, Jun Sung; Cho, Hyunkag; Lee, Alvin Shiulain

    2010-01-01

    School shooting cases since the late 1990s have prompted school officials and legislators to develop and implement programs and measures that would prevent violence in school. Despite the number of explanations by the media, politicians, organizations, and researchers about the etiology of school shootings, we are not united in our understanding…

  10. Shoot Differentiation in Callus Cultures of Datura Innoxia

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1973-01-01

    promoted shoot differentiation. Gibberellic acid inhibited shoot formation weakly, but inhibited proper leaf blade formation. Root differentiation was rare. The callus cultures of Datura innoxia grew rapidly (100-fold in 4 weeks) on a slightly modified Murashige and Skoog medium (0.5 mg/l thiamin · HCl, p...

  11. Initiation and growth of shoots of Gongronema latifolia Benth stem ...

    African Journals Online (AJOL)

    There was significant reduction in number of days to shoot initiation and growth in sawdust medium in the wet season. Sawdust and soil gave a better performance of the cuttings in opening of apical buds, initiation of shoots, percentage of rooted cuttings, number of vines, vine length and number of opposite leaves on vines ...

  12. Mental illness, mass shootings, and the politics of American firearms.

    Science.gov (United States)

    Metzl, Jonathan M; MacLeish, Kenneth T

    2015-02-01

    Four assumptions frequently arise in the aftermath of mass shootings in the United States: (1) that mental illness causes gun violence, (2) that psychiatric diagnosis can predict gun crime, (3) that shootings represent the deranged acts of mentally ill loners, and (4) that gun control "won't prevent" another Newtown (Connecticut school mass shooting). Each of these statements is certainly true in particular instances. Yet, as we show, notions of mental illness that emerge in relation to mass shootings frequently reflect larger cultural stereotypes and anxieties about matters such as race/ethnicity, social class, and politics. These issues become obscured when mass shootings come to stand in for all gun crime, and when "mentally ill" ceases to be a medical designation and becomes a sign of violent threat.

  13. Tips for Postpartum Dads and Partners

    Science.gov (United States)

    ... Blues: Partners Interview with Wade Bowen Coping with Suicide & Loss Tips for Postpartum Dads and Partners Pregnancy and postpartum mood and anxiety disorders affect the whole family. Here are some tips ...

  14. Tips for Reducing Pesticide Impacts on Wildlife

    Science.gov (United States)

    This Web page provides tips for pesticide users in residential and agricultural settings, as well as tips for certified pesticide applicators for ways to protect wildlife from potentially harmful effects of pesticides.

  15. Sound source location in cavitating tip vortices

    International Nuclear Information System (INIS)

    Higuchi, H.; Taghavi, R.; Arndt, R.E.A.

    1985-01-01

    Utilizing an array of three hydrophones, individual cavitation bursts in a tip vortex could be located. Theoretically, four hydrophones are necessary. Hence the data from three hydrophones are supplemented with photographic observation of the cavitating tip vortex. The cavitation sound sources are found to be localized to within one base chord length from the hydrofoil tip. This appears to correspond to the region of initial tip vortex roll-up. A more extensive study with a four sensor array is now in progress

  16. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States); Elliott, Eric D., E-mail: eric.elliott@osumc.edu [The Ohio State University Wexner Medical Center, Division of Interventional Radiology, Department of Radiology (United States); Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu; Hanje, A. James, E-mail: James.Hanje@osumc.edu [The Ohio State University Wexner Medical Center, Division of Gastroenterology and Hepatology, Department of Medicine (United States); Saad, Wael E. A., E-mail: wsaad@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States)

    2016-07-15

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  17. The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment

    NARCIS (Netherlands)

    Allen, P.M.; Latham, K.; Mann, D.L.; Ravensbergen, H.J.C.; Myint, J.

    2016-01-01

    The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle,

  18. Identification and functional analysis of endothelial tip cell-enriched genes.

    Science.gov (United States)

    del Toro, Raquel; Prahst, Claudia; Mathivet, Thomas; Siegfried, Geraldine; Kaminker, Joshua S; Larrivee, Bruno; Breant, Christiane; Duarte, Antonio; Takakura, Nobuyuki; Fukamizu, Akiyoshi; Penninger, Josef; Eichmann, Anne

    2010-11-11

    Sprouting of developing blood vessels is mediated by specialized motile endothelial cells localized at the tips of growing capillaries. Following behind the tip cells, endothelial stalk cells form the capillary lumen and proliferate. Expression of the Notch ligand Delta-like-4 (Dll4) in tip cells suppresses tip cell fate in neighboring stalk cells via Notch signaling. In DLL4(+/-) mouse mutants, most retinal endothelial cells display morphologic features of tip cells. We hypothesized that these mouse mutants could be used to isolate tip cells and so to determine their genetic repertoire. Using transcriptome analysis of retinal endothelial cells isolated from DLL4(+/-) and wild-type mice, we identified 3 clusters of tip cell-enriched genes, encoding extracellular matrix degrading enzymes, basement membrane components, and secreted molecules. Secreted molecules endothelial-specific molecule 1, angiopoietin 2, and apelin bind to cognate receptors on endothelial stalk cells. Knockout mice and zebrafish morpholino knockdown of apelin showed delayed angiogenesis and reduced proliferation of stalk cells expressing the apelin receptor APJ. Thus, tip cells may regulate angiogenesis via matrix remodeling, production of basement membrane, and release of secreted molecules, some of which regulate stalk cell behavior.

  19. Injector tip for an internal combustion engine

    Science.gov (United States)

    Shyu, Tsu Pin; Ye, Wen

    2003-05-20

    This invention relates to a the tip structure of a fuel injector as used in a internal combustion engine. Internal combustion engines using Homogeneous Charge Compression Ignition (HCCI) technology require a tip structure that directs fuel spray in a downward direction. This requirement necessitates a tip design that is capable of withstanding mechanical stresses associated with the design.

  20. Pulsed growth of fungal hyphal tips.

    Science.gov (United States)

    López-Franco, R; Bartnicki-Garcia, S; Bracker, C E

    1994-12-06

    Somatic fungal hyphae are generally assumed to elongate at steady linear rates when grown under constant environmental conditions with ample nutrients. However, patterns of pulsed hyphal elongation were detected during apparent steady growth of hyphal tips in fungi from several major taxonomic groups (Oomycetes, Pythium aphanidermatum and Saprolegnia ferax; Zygomycetes, Gilbertella persicaria; Deuteromycetes, Trichoderma viride; Ascomycetes, Neurospora crassa and Fusarium culmorum; Basidiomycetes, Rhizoctonia solani). Growing hyphal tips were recorded with video-enhanced phase-contrast microscopy at high magnification, and digital images were measured at very short time intervals (1-5 s). In all fungi tested, the hyphal elongation rate was never perfectly steady but fluctuated continuously with alternating periods of fast and slow growth at more or less regular intervals. Pulsed growth was observed in fungi differing in cell diameter, overall growth rate, taxonomic position, and presence and pattern of Spitzenkörper organization, suggesting that this is a general phenomenon. Frequency and amplitude of the pulses varied among the test organisms. T. viride and N. crassa showed the most frequent pulses (average of 13-14 per min), and F. culmorum the least frequent (2.7 per min). Average pulse amplitude varied from 0.012 microns/s for F. culmorum to 0.068 microns/s for G. persicaria. In F. culmorum and T. viride, the fast phase of the growth pulses was correlated with the merger of satellite Spitzenkörper with the main Spitzenkörper. These findings are consistent with a causal relationship between fluctuations in the overall rate of secretory vesicle delivery/discharge at the hyphal apex and the fluctuations in hyphal elongation rate.

  1. Growing Plants and Minds

    Science.gov (United States)

    Presser, Ashley Lewis; Kamdar, Danae; Vidiksis, Regan; Goldstein, Marion; Dominguez, Ximena; Orr, Jillian

    2017-01-01

    Many preschool classrooms explore plant growth. However, because many plants take a long time to grow, it is often hard to facilitate engagement in some practices (i.e., since change is typically not observable from one day to another, children often forget their prior predictions or cannot recall what plants looked like days or weeks earlier).…

  2. Effects of ABA application on cessation of shoot elongation in long-day grown Norway spruce seedlings.

    Science.gov (United States)

    Heide, O M

    1986-06-01

    Abscisic acid (ABA) was applied in lanolin to apical buds of Norway spruce (Picea abies (L.) Karst.) seedlings actively growing in a 24 h photoperiod. At a rate of 100 microg per plant, ABA suspended shoot elongation for about three weeks in the majority of plants but failed to induce normal winter buds. The role of ABA in the induction of dormancy is thus uncertain in conifers as well as in deciduous woody plants.

  3. The shooting method and multiple solutions of two/multi-point BVPs of second-order ODE

    Directory of Open Access Journals (Sweden)

    Man Kam Kwong

    2006-06-01

    Full Text Available Within the last decade, there has been growing interest in the study of multiple solutions of two- and multi-point boundary value problems of nonlinear ordinary differential equations as fixed points of a cone mapping. Undeniably many good results have emerged. The purpose of this paper is to point out that, in the special case of second-order equations, the shooting method can be an effective tool, sometimes yielding better results than those obtainable via fixed point techniques.

  4. Shoot growth of Merlot and Cabernet Sauvignon grapevine varieties

    Directory of Open Access Journals (Sweden)

    Marcelo Borghezan

    2012-02-01

    Full Text Available The objective of this work was to evaluate shoot growth of the grapevine varieties Merlot and Cabernet Sauvignon, during 2006/2007, and Cabernet Sauvignon, during 2008/2009, in São Joaquim, SC, Brazil. The experiment was carried out in a commercial vineyard trained on a vertical trellis system. The shoots of the central part of the plants were selected, and the lengths from the base to the apex of 20 shoots per cultivar were evaluated. In 2006/2007, monitoring began at pruning, on 9/15/2006, and ended on 2/6/2007, totalizing 144 days of evaluation. During the 2008/2009 cycle, phenology and shoot growth for 'Cabernet Sauvignon' were assessed from grape development (1/13/2009 (pea-sized grapes until shoot vegetative growth had ceased. Budburst occurred in the second half of September, and shoot-growth cessation occurred during ripening. Higher growth rates (about 4 cm per day were observed in pre- and post-flowering, followed by reduction due to the competition for photosynthates for the formation of flowers and bunches. Temperature and photoperiod induce grapevine shoots to cease growth in the highland regions of Santa Catarina State, Brazil.

  5. Metabolic changes associated with shoot formation in tobacco callus cultures

    Energy Technology Data Exchange (ETDEWEB)

    Grady, K.L.

    1982-08-01

    Callus tissue derived from Nicotiana tabacum L. stem pith parenchyma cells was grown either on medium which maintains the callus in an undifferentiated state, or on medium which induces the formation of shoots. Two complementary types of studies were performed with the goal of establishing metabolic markers for the initiation of shoot formation: one designed to characterize the flow of radioactive sucrose into various metabolic pools, and one which allowed measurement of intermediary metabolite concentrations. In the former, callus tissue was incubated in (U-/sup 14/C)sucrose for periods up to one hour, and patterns of metabolite labelling in tissue grown on shoot-forming and non-shoot-forming media were compared. In the latter studies, tissue was grown for an entire subculture period on non-shoot-forming medium labelled with (U-/sup 14/C)sucrose, then subcultured to labelled non-shoot-forming or shoot-forming media, and sampled at intervals during the first week of growth. 189 references.

  6. Firearm Legislation and Fatal Police Shootings in the United States.

    Science.gov (United States)

    Kivisto, Aaron J; Ray, Bradley; Phalen, Peter L

    2017-07-01

    To examine whether stricter firearm legislation is associated with rates of fatal police shootings. We used a cross-sectional, state-level design to evaluate the effect of state-level firearm legislation on rates of fatal police shootings from January 1, 2015, through October 31, 2016. We measured state-level variation in firearm laws with legislative scorecards from the Brady Center, and for fatal police shootings we used The Counted, an online database maintained by The Guardian. State-level firearm legislation was significantly associated with lower rates of fatal police shootings (incidence rate ratio = 0.961; 95% confidence interval = 0.939, 0.984). When we controlled for sociodemographic factors, states in the top quartile of legislative strength had a 51% lower incidence rate than did states in the lowest quartile. Laws aimed at strengthening background checks, promoting safe storage, and reducing gun trafficking were associated with fewer fatal police shootings. Legislative restrictions on firearms are associated with reductions in fatal police shootings. Public Health Implications. Although further research is necessary to determine causality and potential mechanisms, firearm legislation is a potential policy solution for reducing fatal police shootings in the United States.

  7. Exposure to lead in South African shooting ranges

    International Nuclear Information System (INIS)

    Mathee, Angela; Jager, Pieter de; Naidoo, Shan; Naicker, Nisha

    2017-01-01

    Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p<0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. - Highlights: • This is the first study, to our knowledge, of lead exposure in shooting ranges in an African setting. • This study indicates highly elevated lead exposure amongst the users of certain private shooting ranges in South Africa. • Lead exposure may be a serious, yet under-studied, source of adult lead exposure in South Africa, and possibly elsewhere on the African continent.

  8. Metabolic changes associated with shoot formation in tobacco callus cultures

    International Nuclear Information System (INIS)

    Grady, K.L.

    1982-08-01

    Callus tissue derived from Nicotiana tabacum L. stem pith parenchyma cells was grown either on medium which maintains the callus in an undifferentiated state, or on medium which induces the formation of shoots. Two complementary types of studies were performed with the goal of establishing metabolic markers for the initiation of shoot formation: one designed to characterize the flow of radioactive sucrose into various metabolic pools, and one which allowed measurement of intermediary metabolite concentrations. In the former, callus tissue was incubated in [U- 14 C]sucrose for periods up to one hour, and patterns of metabolite labelling in tissue grown on shoot-forming and non-shoot-forming media were compared. In the latter studies, tissue was grown for an entire subculture period on non-shoot-forming medium labelled with [U- 14 C]sucrose, then subcultured to labelled non-shoot-forming or shoot-forming media, and sampled at intervals during the first week of growth. 189 references

  9. Exposure to lead in South African shooting ranges

    Energy Technology Data Exchange (ETDEWEB)

    Mathee, Angela [South African Medical Research Council, Environment & Health Research Unit, PO Box 87373, Houghton 2041 (South Africa); University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); University of Johannesburg (Environmental Health Department, Faculty of Health Sciences), PO Box 524, Auckland Park, Johannesburg 2006 (South Africa); Jager, Pieter de [University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); National Health Laboratory Service (Epidemiology and Surveillance Unit, National Institute for Occupational Health), PO Box 4788, Johannesburg 2000 (South Africa); Naidoo, Shan [University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); Naicker, Nisha [South African Medical Research Council, Environment & Health Research Unit, PO Box 87373, Houghton 2041 (South Africa); University of the Witwatersrand, School of Public Health, PO Box Wits, Johannesburg 2050 (South Africa); University of Johannesburg, Environmental Health Department, Faculty of Health Sciences, PO Box 524, Auckland Park, Johannesburg 2006 (South Africa)

    2017-02-15

    Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p<0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. - Highlights: • This is the first study, to our knowledge, of lead exposure in shooting ranges in an African setting. • This study indicates highly elevated lead exposure amongst the users of certain private shooting ranges in South Africa. • Lead exposure may be a serious, yet under-studied, source of adult lead exposure in South Africa, and possibly elsewhere on the African continent.

  10. Shoot bending promotes flower bud formation by miRNA-mediated regulation in apple (Malus domestica Borkh.).

    Science.gov (United States)

    Xing, Libo; Zhang, Dong; Zhao, Caiping; Li, Youmei; Ma, Juanjuan; An, Na; Han, Mingyu

    2016-02-01

    Flower induction in apple (Malus domestica Borkh.) trees plays an important life cycle role, but young trees produce fewer and inferior quality flower buds. Therefore, shoot bending has become an important cultural practice, significantly promoting the capacity to develop more flower buds during the growing seasons. Additionally, microRNAs (miRNAs) play essential roles in plant growth, flower induction and stress responses. In this study, we identified miRNAs potentially involved in the regulation of bud growth, and flower induction and development, as well as in the response to shoot bending. Of the 195 miRNAs identified, 137 were novel miRNAs. The miRNA expression profiles revealed that the expression levels of 68 and 27 known miRNAs were down-regulated and up-regulated, respectively, in response to shoot bending, and that the 31 differentially expressed novel miRNAs between them formed five major clusters. Additionally, a complex regulatory network associated with auxin, cytokinin, abscisic acid (ABA) and gibberellic acid (GA) plays important roles in cell division, bud growth and flower induction, in which related miRNAs and targets mediated regulation. Among them, miR396, 160, 393, and their targets associated with AUX, miR159, 319, 164, and their targets associated with ABA and GA, and flowering-related miRNAs and genes, regulate bud growth and flower bud formation in response to shoot bending. Meanwhile, the flowering genes had significantly higher expression levels during shoot bending, suggesting that they are involved in this regulatory process. This study provides a framework for the future analysis of miRNAs associated with multiple hormones and their roles in the regulation of bud growth, and flower induction and formation in response to shoot bending in apple trees. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Differences in U root-to-shoot translocation between plant species explained by U distribution in roots

    Energy Technology Data Exchange (ETDEWEB)

    Straczek, Anne; Duquene, Lise [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Wegrzynek, Dariusz [IAEA, Seibersdorf Laboratories, A-2444 Seibersdorf (Austria); Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Chinea-Cano, Ernesto [IAEA, Seibersdorf Laboratories, A-2444 Seibersdorf (Austria); Wannijn, Jean [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Navez, Jacques [Royal Museum of Africa, Department of Geology, Leuvensesteenweg 13, 3080 Tervuren (Belgium); Vandenhove, Hildegarde, E-mail: hvandenh@sckcen.b [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)

    2010-03-15

    Accumulation and distribution of uranium in roots and shoots of four plants species differing in their cation exchange capacity of roots (CECR) was investigated. After exposure in hydroponics for seven days to 100 mumol U L{sup -1}, distribution of uranium in roots was investigated through chemical extraction of roots. Higher U concentrations were measured in roots of dicots which showed a higher CECR than monocot species. Chemical extractions indicated that uranium is mostly located in the apoplasm of roots of monocots but that it is predominantly located in the symplasm of roots of dicots. Translocation of U to shoot was not significantly affected by the CECR or distribution of U between symplasm and apoplasm. Distribution of uranium in roots was investigated through chemical extraction of roots for all species. Additionally, longitudinal and radial distribution of U in roots of maize and Indian mustard, respectively showing the lowest and the highest translocation, was studied following X-ray fluorescence (XRF) analysis of specific root sections. Chemical analysis and XRF analysis of roots of maize and Indian mustard clearly indicated a higher longitudinal and radial transport of uranium in roots of Indian mustard than in roots of maize, where uranium mostly accumulated in root tips. These results showed that even if CECR could partly explain U accumulation in roots, other mechanisms like radial and longitudinal transport are implied in the translocation of U to the shoot.

  12. Differences in U root-to-shoot translocation between plant species explained by U distribution in roots

    International Nuclear Information System (INIS)

    Straczek, Anne; Duquene, Lise; Wegrzynek, Dariusz; Chinea-Cano, Ernesto; Wannijn, Jean; Navez, Jacques; Vandenhove, Hildegarde

    2010-01-01

    Accumulation and distribution of uranium in roots and shoots of four plants species differing in their cation exchange capacity of roots (CECR) was investigated. After exposure in hydroponics for seven days to 100 μmol U L -1 , distribution of uranium in roots was investigated through chemical extraction of roots. Higher U concentrations were measured in roots of dicots which showed a higher CECR than monocot species. Chemical extractions indicated that uranium is mostly located in the apoplasm of roots of monocots but that it is predominantly located in the symplasm of roots of dicots. Translocation of U to shoot was not significantly affected by the CECR or distribution of U between symplasm and apoplasm. Distribution of uranium in roots was investigated through chemical extraction of roots for all species. Additionally, longitudinal and radial distribution of U in roots of maize and Indian mustard, respectively showing the lowest and the highest translocation, was studied following X-ray fluorescence (XRF) analysis of specific root sections. Chemical analysis and XRF analysis of roots of maize and Indian mustard clearly indicated a higher longitudinal and radial transport of uranium in roots of Indian mustard than in roots of maize, where uranium mostly accumulated in root tips. These results showed that even if CECR could partly explain U accumulation in roots, other mechanisms like radial and longitudinal transport are implied in the translocation of U to the shoot.

  13. TIP maker and TIP marker; EB1 as a master controller of microtubule plus ends.

    Science.gov (United States)

    Vaughan, Kevin T

    2005-10-24

    The EB1 protein is a member of the exciting and enigmatic family of microtubule (MT) tip-tracking proteins. EB1 acts as an exquisite marker of dynamic MT plus ends in some cases, whereas in others EB1 is thought to directly dictate the behavior of the plus ends. How EB1 differentiates between these two roles remains unclear; however, a growing list of interactions between EB1 and other MT binding proteins suggests there may be a single mechanism. Adding another layer of complexity to these interactions, two studies published in this issue implicate EB1 in cross-talk between mitotic MTs and between MTs and actin filaments (Goshima et al., p. 229; Wu et al., p. 201). These results raise the possibility that EB1 is a central player in MT-based transport, and that the activity of MT-binding proteins depends on their ability or inability to interact with EB1.

  14. Shoot growth of Merlot and Cabernet Sauvignon grapevine varieties

    OpenAIRE

    Marcelo Borghezan; Olavo Gavioli; Hamilton Justino Vieira; Aparecido Lima da Silva

    2012-01-01

    The objective of this work was to evaluate shoot growth of the grapevine varieties Merlot and Cabernet Sauvignon, during 2006/2007, and Cabernet Sauvignon, during 2008/2009, in São Joaquim, SC, Brazil. The experiment was carried out in a commercial vineyard trained on a vertical trellis system. The shoots of the central part of the plants were selected, and the lengths from the base to the apex of 20 shoots per cultivar were evaluated. In 2006/2007, monitoring began at pruning, on 9/15/2006, ...

  15. Methodology of shooting training using modern IT techniques

    Science.gov (United States)

    Gudzbeler, Grzegorz; Struniawski, Jarosław

    2017-08-01

    Mastering, improvement, shaping and preservation of skills of safe, efficient and effective use of the firearm requires the use of relevant methodology of conducting the shooting training. However reality of police trainings does not usually allow for intensive training shooting with the use of ammunition. An alternative solution is the use of modern training technologies. Example of this is the "Virtual system of improvement tactics of intervention services responsible for security and shooting training." Introduction of stimulator to police trainings will enable complete stuff preparation to achieve its tasks, creating potential of knowledge and experience in many areas, far exceeding the capabilities of conventional training.

  16. Field evaluation of regenerated plants by somatic embryogenesis from shoots apexes of axillary buds in ´Navolean’ (Musa spp., AAB.

    Directory of Open Access Journals (Sweden)

    Jorge López

    2005-04-01

    Full Text Available The use of shoots apexes from axilary buds for callus induction with embryogenic structures in plantain ‘Navolean’ (Group AAB permitted to develop a plant regeneration method through out somatic embryogenesis. In order to know the phenotypic variants that may be produced with the previously mentioned method , 1000 plants were planted in field conditions in comparison to those coming from somatic embryos obtained from multibuds as initial explants and organogenesis-derived plants (shoot tipsand conventionally derived plants (corms, during two growing cycles. The main morphological characters and yield components were evaluated. The total frequency of somaclonal variation during the first growing cycle in plants coming from somatic embryos obtained from shoots apexes from axilary buds as initial explants were 1.1%, and 8,6% in regenerated plants from somatic embryos obtained from multi-buds as initial explants. Later, in this same growing cycle, plants regenerated from somatic embryos (both sources showed a similar performance between them and they were significantly superior in all evaluated variants in comparison to corm-derived plants. In the second growing cycle, significant differences were not observed in yield components of suckers from evaluated plants, in spite of the propagation method used. With regard to somaclonal variation, the best performance was obtained with shoots apexes from axilary buds as explants. Finally, the feasibility of using the new method was shown. Key words: embryogenic cell suspensions, somaclonal variation

  17. How to Grow Old

    Institute of Scientific and Technical Information of China (English)

    Bertrand Russell

    2008-01-01

    <正>1. In spite of the title, this article will really be on how not to grow old, which, at my time of life, is a much more important subject. My first advice would be to choose your ancestors carefully. Although both my parents died young, I have done well in this respect as regards my other ancestors. My maternal grandfather, it is true, was cut off in the flower of his youth at the age of sixty-seven,

  18. Preventing School Shootings: A Public Health Approach to Gun Violence

    Science.gov (United States)

    2013-03-01

    pedagogical goals. The incidents of school shootings on college campuses can be prevented through the collaboration and application of whole-of...interesting accompaniment to school violence. 26 Date Place Outcome May 16, 1986 Cokeville Elementary School, Sweetwater County, Wyoming

  19. 76 FR 1339 - Pine Shoot Beetle; Additions to Quarantined Areas

    Science.gov (United States)

    2011-01-10

    ... Domestic Programs, PPQ, APHIS, 4700 River Road Unit 26, Riverdale, MD 20737-1231; (301) 734-5705... distorted growth in host trees. Large infestations of PSB typically kill most of the lateral shoots near the...

  20. Effect of benzylaminopurine (BAP) pulsing on in vitro shoot ...

    African Journals Online (AJOL)

    user

    2011-03-28

    Mar 28, 2011 ... Research Cluster, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia. Accepted 12 ... number of bud formation in shoot cultures of Musa acuminata cv. ... In tissue culture, plant growth regulators (PGR) are.

  1. Roots & Shoots: A model for active environmental protection ...

    African Journals Online (AJOL)

    Madagascar is facing severe environmental problems. One approach to engage possible future stakeholders and to raise awareness for environmental concerns is the Roots & Shoots program. On the following the program and its philosophy are presented.

  2. In vitro shoot multiplication and conservation of Caralluma ...

    African Journals Online (AJOL)

    Jane

    2011-03-30

    Burm. f.) Merrill. In Vitro Cell Deve. Biol. Plant. 41: 124-128. Thomas TD, Shankar S (2009). Multiple shoot induction and callus regeneration in Sarcostemma brevistigma Wight & Arnott, a rare medicinal plant. Plant Biotechnol.

  3. Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L

    Science.gov (United States)

    Chisnell, J. R.; Bandurski, R. S.

    1988-01-01

    Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyl-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot.

  4. Plant uptake and availability of antimony, lead, copper and zinc in oxic and reduced shooting range soil.

    Science.gov (United States)

    Hockmann, Kerstin; Tandy, Susan; Studer, Björn; Evangelou, Michael W H; Schulin, Rainer

    2018-03-19

    Shooting ranges polluted by antimony (Sb), lead (Pb), copper (Cu) and zinc (Zn) are used for animal grazing, thus pose a risk of contaminants entering the food chain. Many of these sites are subject to waterlogging of poorly drained soils. Using field lysimeter experiments, we compared Sb, Pb, Cu and Zn uptake by four common pasture plant species (Lolium perenne, Trifolium repens, Plantago lanceolata and Rumex obtusifolius) growing on a calcareous shooting range soil under waterlogged and drained conditions. To monitor seasonal trends, the same plants were collected at three times over the growing season. Additionally, variations in soil solution concentrations were monitored at three depths over the experiment. Under reducing conditions, soluble Sb concentrations dropped from ∼50 μg L -1 to ∼10 μg L -1 , which was attributed to the reduction of Sb(V) to Sb(III) and the higher retention of the trivalent species by the soil matrix. Shoot Sb concentrations differed by a factor of 60 between plant species, but remained at levels <0.3 μg g -1 . Despite the difference in soil solution concentrations between treatments, total Sb accumulation in shoots for plants collected on the waterlogged soil did not change, suggesting that Sb(III) was much more available for plant uptake than Sb(V), as only 10% of the total Sb was present as Sb(III). In contrast to Sb, Pb, Cu and Zn soil solution concentrations remained unaffected by waterlogging, and shoot concentrations were significantly higher in the drained treatment for many plant species. Although showing an increasing trend over the season, shoot metal concentrations generally remained below regulatory values for fodder plants (40 μg g -1  Pb, 150 μg g -1 Zn, 15-35 μg g -1 Cu), indicating a low risk of contaminant transfer into the food chain under both oxic and anoxic conditions for the type of shooting range soil investigated in this study. Copyright © 2018 Elsevier Ltd. All rights

  5. The effect of tillage intensity on soil structure and winter wheat root/shoot growth

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Hansen, Elly Møller; Olesen, Jørgen E

    2008-01-01

    was followed during the growing seasons using spectral reflectance and mini-rhizotron measurements, respectively. A range of soil physical properties were measured. We found decreased early season shoot and root growth with decreasing tillage intensity. Differences diminished later in the growing season...... of this study was to investigate the effect of tillage intensity on crop growth dynamics and soil structure. A tillage experiment was established in autumn 2002 on two Danish sandy loams (Foulum and Flakkebjerg) in a cereal-based crop rotation. The tillage systems included in this study were direct drilling (D...... with decreasing tillage intensity for the first year winter wheat at Foulum. In general ploughing resulted in the highest grain yields. This study highlights the important interaction between soil structure and crop growth dynamics....

  6. The Hidden Advantage in Shoot/Don’t Shoot Simulation Exercises for Police Recruit Training

    Directory of Open Access Journals (Sweden)

    Amanda Davies

    2015-03-01

    Full Text Available During the past thirty-five years, developments in computer-related technology have been providing increasingly more sophisticated simulation alternatives for training law enforcement officers. Such developments have leveraged on the back of progress achieved in the aviation, military and medical professions as law enforcement educators seek to address the challenges of training for high-risk, high-stakes professional environments. While globally, simulation based learning exercises are at the forefront in use-of-force training with firearms for police recruits there is limited published research which views the influence of these exercises on operational practice through the lens of the police recruit as they engage with the demands of their volatile, unpredictable workplace. This paper discusses a case study of a cohort of 372 police recruits whose police academy education program included participation in simulation based learning exercises centred on decision making in use-of-force. The pivotal inclusion in the study was the opportunity for the police recruits to reflect on the influence of the simulation exercise experience from an operational perspective. The study revealed an unvoiced advantage—while trainers are focusing on the amount of ammunition used, the marksmanship accuracy, and the justification for the use-of-force, the students are unconsciously building a repertoire of realistic experiences as a reference library for the moment of decision in real life shoot/don’t shoot incidents.

  7. Twitter Tips, Tricks, and Tweets

    CERN Document Server

    McFedries, Paul

    2010-01-01

    Maximize your fun and boost your productivity with this updated, full-color guide to tantalizing Twitter tips!. The popularity of Twitter continues to soar, and is fast becoming the most popular social networking site online. Whether you're looking to learn how to set up an account for the first time or are on the prowl for some cool third-party Twitter apps, this full-color guide will boost your entire Twitter experience. Allowing you to communicate with fellow Twitters within a 140-character limit, this fun and fascinating social networking tool is easier than maintaining a blog and quicker

  8. Windows 8 visual quick tips

    CERN Document Server

    McFedries, Paul

    2012-01-01

    Easy-in, easy-out format covers all the bells and whistles of Windows 8 If you want to learn how to work smarter and faster in Microsoft's Windows 8 operating system, this easy-to-use, compact guide delivers the goods. Designed for visual learners, it features short explanations and full-color screen shots on almost every page, and it's packed with timesaving tips and helpful productivity tricks. From enhancing performance and managing digital content to setting up security and much more, this handy guide will help you get more out of Windows 8. Uses full-color screen shots and short, step-by-

  9. DETECTING LASER SPOT IN SHOOTING SIMULATOR USING AN EMBEDDED CAMERA

    OpenAIRE

    Soetedjo, Aryuanto; Mahmudi, Ali; Ibrahim Ashari, M.; Ismail Nakhoda, Yusuf

    2017-01-01

    This paper presents the application of an embedded camera system for detecting laser spot in the shooting simulator. The proposed shooting simulator uses a specific target box, where the circular pattern target is mounted. The embedded camera is installed inside the box to capture the circular pattern target and laser spot image. To localize the circular pattern automatically, two colored solid circles are painted on the target. This technique allows the simple and fast color tracking to trac...

  10. Coumarins and alkaloids in shoot culture of Ruta graveolens L.

    Directory of Open Access Journals (Sweden)

    Halina Ekiert

    2014-01-01

    Full Text Available A shoot culture of Ruta graveolens L. (Rutaceae was maintained in the stationary liquid phase. From the cultured shoots seven compounds were isolated and identified as psoralen, bergapten, xanthotoxin, isopimpinellin (linear furanocoumarins, rutamarin (linear dihydrofuranocoumarin, kokusaginine and skimmianine (furanoquinoline alkaloids by spectral methods. The compounds are known as secondary metabolites of the intact plant, as well as its cell and tissue cultures.

  11. Direct shoot organogenesis of Digitalis trojana Ivan., an endemic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... An efficient protocol for in vitro propagation of Digitalis trojana Ivan. was developed via adventitious shoot regeneration. Leaf explants were cultured on MS which were supplemented with different concentrations of NAA (0.1, 0.5, 1.0 mg/ml) and BAP (0.1, 0.5, 1.0, 3.0, 5.0 mg/ml) for shoot formation.

  12. Bud structure, position and fate generate various branching patterns along shoots of closely related Rosaceae species: a review

    Directory of Open Access Journals (Sweden)

    Evelyne eCostes

    2014-12-01

    Full Text Available Branching in temperate plants is closely linked to bud fates, either floral or vegetative. Here, we review how the fate of meristematic tissues contained in buds and their position along a shoot imprint specific branching patterns which differ among species. Through examples chosen in closely related species in different genera of the Rosaceae family, a panorama of patterns is apparent. Patterns depend on whether vegetative and floral buds are borne individually or together in mixed buds, develop as the shoot grows or after a rest period, and are located in axillary or terminal positions along the parent shoot. The resulting branching patterns are conserved among varieties in a given species but progressively change with the parent shoot length during plant ontogeny. They can also be modulated by agronomic and environmental conditions. The existence of various organizations in the topology and fate of meristematic tissues and their appendages in closely related species questions the between-species conservation of physiological and molecular mechanisms leading to bud outgrowth vs quiescence and to floral induction vs vegetative development.

  13. Bud structure, position and fate generate various branching patterns along shoots of closely related Rosaceae species: a review.

    Science.gov (United States)

    Costes, Evelyne; Crespel, Laurent; Denoyes, Béatrice; Morel, Philippe; Demene, Marie-Noëlle; Lauri, Pierre-Eric; Wenden, Bénédicte

    2014-01-01

    Branching in temperate plants is closely linked to bud fates, either floral or vegetative. Here, we review how the fate of meristematic tissues contained in buds and their position along a shoot imprint specific branching patterns which differ among species. Through examples chosen in closely related species in different genera of the Rosaceae family, a panorama of patterns is apparent. Patterns depend on whether vegetative and floral buds are borne individually or together in mixed buds, develop as the shoot grows or after a rest period, and are located in axillary or terminal positions along the parent shoot. The resulting branching patterns are conserved among varieties in a given species but progressively change with the parent shoot length during plant ontogeny. They can also be modulated by agronomic and environmental conditions. The existence of various organizations in the topology and fate of meristematic tissues and their appendages in closely related species questions the between-species conservation of physiological and molecular mechanisms leading to bud outgrowth vs. quiescence and to floral induction vs. vegetative development.

  14. Ferns: the missing link in shoot evolution and development

    Directory of Open Access Journals (Sweden)

    Andrew Robert George Plackett

    2015-11-01

    Full Text Available Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants, the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

  15. Photoperiod and growth regulators on in vitro shoot induction in Heliconia latispatha

    Directory of Open Access Journals (Sweden)

    Antonio Anderson de Jesus Rodrigues

    2016-12-01

    Full Text Available Considering the growing economic importance of tropical flowers and the advantages of techniques applied to the in vitro cultivation of these plants, it is necessary to carry out studies to evaluate growth in species such as Heliconia latispatha. The aim of this study therefore, was to evaluate in vitro shoot induction for different concentrations of BAP and NAA and as a function of the photoperiod. Explants from zygotic embryos were inoculated in MS medium containing different concentrations of BAP (0.0, 0.5, 1.0, 1.5, 2.0 or 2.5 mg L-1, with the cultures kept in a growth room at a temperature of 24.0 ± 2.0° C, under a photoperiod of 12 and 16 hours of light and a light intensity of 30 μmol m-2 s-1. At 21, 28, 35, 42 and 49 days after inoculation, the number of shoots per explant was evaluated. The treatment at the BAP concentration that gave the best multiplication rate (2.5 mg L-1 was set, and was tested in a further trial with different concentrations of NAA (0.0, 0.2, 0.4, 0 6, 0.8 or 1.0 mg L-1 under the same conditions as the previous experiment. The experimental designs were completely randomised, with five replications, and analysed in a 6 x 2 factorial. The data were submitted to analysis of variance and regression. No significant differences were seen in relation to the photoperiod or its interaction with the cytokinin and auxin under test. Multiplication was greater in the presence of 2.5 mg L-1 BAP, which gave a rate of 1.25 shoots/explant at 49 days of in vitro culture. The association of this BAP dosage with 1.0 mg L-1 NAA was even more efficient, producing 1.83 shoots per explant at 30 days of growth. The use of BAP together with NAA is beneficial to the induction of shoots in H. latispatha.

  16. Towards easy and reliable AFM tip shape determination using blind tip reconstruction

    International Nuclear Information System (INIS)

    Flater, Erin E.; Zacharakis-Jutz, George E.; Dumba, Braulio G.; White, Isaac A.; Clifford, Charles A.

    2014-01-01

    Quantitative determination of the geometry of an atomic force microscope (AFM) probe tip is critical for robust measurements of the nanoscale properties of surfaces, including accurate measurement of sample features and quantification of tribological characteristics. Blind tip reconstruction, which determines tip shape from an AFM image scan without knowledge of tip or sample shape, was established most notably by Villarrubia [J. Res. Natl. Inst. Stand. Tech. 102 (1997)] and has been further developed since that time. Nevertheless, the implementation of blind tip reconstruction for the general user to produce reliable and consistent estimates of tip shape has been hindered due to ambiguity about how to choose the key input parameters, such as tip matrix size and threshold value, which strongly impact the results of the tip reconstruction. These key parameters are investigated here via Villarrubia's blind tip reconstruction algorithms in which we have added the capability for users to systematically vary the key tip reconstruction parameters, evaluate the set of possible tip reconstructions, and determine the optimal tip reconstruction for a given sample. We demonstrate the capabilities of these algorithms through analysis of a set of simulated AFM images and provide practical guidelines for users of the blind tip reconstruction method. We present a reliable method to choose the threshold parameter corresponding to an optimal reconstructed tip shape for a given image. Specifically, we show that the trend in how the reconstructed tip shape varies with threshold number is so regular that the optimal, or Goldilocks, threshold value corresponds with the peak in the derivative of the RMS difference with respect to the zero threshold curve vs. threshold number. - Highlights: • Blind tip reconstruction algorithms have been implemented and augmented to determine the optimal input parameters. • We demonstrate the capabilities of the algorithms using a simulated AFM

  17. Influence of the tip mass on the tip-sample interactions in TM-AFM

    Energy Technology Data Exchange (ETDEWEB)

    Pishkenari, Hossein Nejat, E-mail: nejat@mech.sharif.edu [Nano-Robotics Laboratory, Center of Excellence in Design, Robotics and Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9465 (Iran, Islamic Republic of); Meghdari, Ali [Nano-Robotics Laboratory, Center of Excellence in Design, Robotics and Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9465 (Iran, Islamic Republic of)

    2011-07-15

    This paper focuses on the influences of the tip mass ratio (the ratio of the tip mass to the cantilever mass), on the excitation of higher oscillation eigenmodes and also on the tip-sample interaction forces in tapping mode atomic force microscopy (TM-AFM). A precise model for the cantilever dynamics capable of accurate simulations is essential for the investigation of the tip mass effects on the interaction forces. In the present work, the finite element method (FEM) is used for modeling the AFM cantilever to consider the oscillations of higher eigenmodes oscillations. In addition, molecular dynamics (MD) is used to calculate precise data for the tip-sample force as a function of tip vertical position with respect to the sample. The results demonstrate that in the presence of nonlinear tip-sample interaction forces, the tip mass ratio plays a significant role in the excitations of higher eigenmodes and also in the normal force applied on the surface. Furthermore, it has been shown that the difference between responses of the FEM and point-mass models in different system operational conditions is highly affected by the tip mass ratio. -- Highlights: {yields} A strong correlation exists between the tip mass ratio and the 18th harmonic amplitude. {yields} Near the critical tip mass ratio a small change in the tip mass may lead to a significant force change. {yields} Inaccuracy of the lumped model depends significantly on the tip mass ratio.

  18. Tip Clearance Control Using Plasma Actuators

    Science.gov (United States)

    2007-03-01

    Clearance Control Using Plasma Actuators 4 posed by Denton (1993). A number of investigators have used partial shrouds, or " winglet " designs to...SDBD actuator Plasma enhanced aerodynamics has been demonstrated in a range of applications involving sepa- ration control, lift enhancement, drag... aerodynamic benefits of a squealer tip geometry. Specifically, the squealer tip is known to reduce the discharge coefficient of the tip gap, thereby

  19. Numerical investigation of tip leakage vortex

    OpenAIRE

    Fredriksen, Vegard

    2017-01-01

    The Kaplan turbine has a small clearance gap between the blade tip and casing to allow the blades to rotate freely. This clearance gap is the cause of an undesirable Tip Leakage Vortex (TLV). A TLV might reduce the turbine efficiency, erode the turbine blades or cause instabilities for the power output. A literature study indicated that the tip clearance gap was a critical parameter affecting the behavior of the TLV. A research gap was observed for an operating Kaplan turbine where the ...

  20. Water Status Related Root-to-Shoot Communication Regulates the Chilling Tolerance of Shoot in Cucumber (Cucumis sativus L.) Plants.

    Science.gov (United States)

    Zhang, Zi-Shan; Liu, Mei-Jun; Gao, Hui-Yuan; Jin, Li-Qiao; Li, Yu-Ting; Li, Qing-Ming; Ai, Xi-Zhen

    2015-10-16

    Although root-to-shoot communication has been intensively investigated in plants under drought, few studies have examined root-to-shoot communication under chilling. Here we explored whether root-to-shoot communication contributes to the chilling-light tolerance of cucumber shoots and clarified the key signal involves in this communication. After leaf discs chilling-light treatment, the photoinhibitions of Photosystem I (PSI) and Photosystem II (PSII) were similar in leaf discs of two cucumber varieties (JY-3 and JC-4). When the whole plants, including roots, were chilled under light, the photosynthetic performances in JC-4 leaves decreased more seriously than that in JY-3 leaves. However, when the water status of leaves was maintained by warming roots or floating the attached leaves on water, the PSII activity and amount of PSI in the leaves of the two varieties were similar after chilling-light treatment. In addition, the differences of PSII activities and amount of PSI between the two varieties under whole plant chilling-light treatment were independent of ABA pretreatment. Above results indicate that (1) the better water status in leaves under chilling contributes to the higher chilling tolerance of JY-3; (2) the water status, rather than an ABA signal, dominates root-to-shoot communication under chilling and the chilling tolerance of cucumber shoot.

  1. RANS computations of tip vortex cavitation

    Science.gov (United States)

    Decaix, Jean; Balarac, Guillaume; Dreyer, Matthieu; Farhat, Mohamed; Münch, Cécile

    2015-12-01

    The present study is related to the development of the tip vortex cavitation in Kaplan turbines. The investigation is carried out on a simplified test case consisting of a NACA0009 blade with a gap between the blade tip and the side wall. Computations with and without cavitation are performed using a R ANS modelling and a transport equation for the liquid volume fraction. Compared with experimental data, the R ANS computations turn out to be able to capture accurately the development of the tip vortex. The simulations have also highlighted the influence of cavitation on the tip vortex trajectory.

  2. Direct calculation of wind turbine tip loss

    DEFF Research Database (Denmark)

    Wood, D.H.; Okulov, Valery; Bhattacharjee, D.

    2016-01-01

    . We develop three methods for the direct calculation of the tip loss. The first is the computationally expensive calculation of the velocities induced by the helicoidal wake which requires the evaluation of infinite sums of products of Bessel functions. The second uses the asymptotic evaluation......The usual method to account for a finite number of blades in blade element calculations of wind turbine performance is through a tip loss factor. Most analyses use the tip loss approximation due to Prandtl which is easily and cheaply calculated but is known to be inaccurate at low tip speed ratio...

  3. Water relations, gas exchange and growth of dominant and suppressed shoots of Arbutus unedo L.

    Science.gov (United States)

    Castell, C; Terradas, J

    1995-06-01

    Basal shoots produced by Arbutus unedo L. after cutting at ground level vary in size and growth rate, and are classified accordingly as dominant or suppressed. The suppressed shoots eventually cease growth and die. In this study, we investigated the role of light and water in the competition among shoots of A. unedo. Dominant and suppressed shoots of A. unedo showed similar leaf water potentials and tissue water relations over the year, suggesting that water status is not responsible for the lack of flushing in suppressed shoots. Although suppressed shoots did not flush under low light, they showed many characteristics of shade-tolerant plants. Leaves of suppressed shoots had lower leaf conductance and light-saturated photosynthetic rate, and higher specific leaf area than leaves of dominant shoots. We conclude that light was the main resource determining competition among shoots and the death of suppressed shoots.

  4. Growing a market economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.

    1997-09-01

    This report presents a microsimulation model of a transition economy. Transition is defined as the process of moving from a state-enterprise economy to a market economy. The emphasis is on growing a market economy starting from basic microprinciples. The model described in this report extends and modifies the capabilities of Aspen, a new agent-based model that is being developed at Sandia National Laboratories on a massively parallel Paragon computer. Aspen is significantly different from traditional models of the economy. Aspen`s emphasis on disequilibrium growth paths, its analysis based on evolution and emergent behavior rather than on a mechanistic view of society, and its use of learning algorithms to simulate the behavior of some agents rather than an assumption of perfect rationality make this model well-suited for analyzing economic variables of interest from transition economies. Preliminary results from several runs of the model are included.

  5. RAPD markers for screening shoot gall maker (Betousa stylophora Swinhoe tolerant genotypes of amla (Phyllanthus emblica L.

    Directory of Open Access Journals (Sweden)

    Sethuraman Thilaga

    2017-12-01

    Full Text Available Phyllanthus emblica Linn. is the most important medicinally useful tree crop in Asian Subcontinent and is severely infested by Betousa stylophora Swinhoe, known as shoot gall maker (SGM. This pest tunnels the shoots of seedlings and actively growing branches of trees and develops gall, leading to stunted growth, unusual branching and death of actively growing shoots. Our study revealed that trees possessing smooth bark were free from the attack of this pest than those with rough bark surface. Unfortunately, this character is not detectable either at seedling stage or during early growth of trees in the orchard. RAPD genetic fingerprinting of trees possessing smooth and rough bark revealed distinguishable and highly reproducible DNA banding pattern between the two genotypes. Of the 20 RAPD primers tested, five of them produced distinguishable RAPD bands between rough and smooth barked genotypes of P. emblica. Trees with smooth bark produced five unique RAPD bands with molecular weight ranging from 350 bp to 1500 bp and those with rough bark produced six RAPD bands (350 bp–650 bp to utilize these DNA bands as potential DNA marker for screening tolerant genotypes of this crop against SGM. The utility of this finding in genetic improvement of this tree crop against SGM is discussed.

  6. The growing fibroadenoma

    International Nuclear Information System (INIS)

    Sanders, Linda M; Sara, Rana

    2015-01-01

    Fibroadenomas (FAs) are the most common tumors of the breast clinically and pathologically in adolescent and young women but may be discovered at any age. With increasing use of core biopsy rather than excision for diagnosis, it is now commonplace to follow these lesions with imaging. To assess the incidence of epithelial abnormalities (atypia, in situ or invasive, ductal or lobular malignancies) in FAs diagnosed by core biopsy and to re-evaluate the management paradigm for any growing FA. A retrospective review of the senior author’s pathology results over 19 years identified 2062 nodular FAs (biopsied by ultrasound or stereotactic guidance). Eighty-three core biopsied FAs were identified which subsequently enlarged. Twelve of 2062 of core biopsied nodules demonstrated atypia, in situ, or invasive malignancy (ductal or lobular) within or adjacent to the FA (0.58%). Eighty-three FAs enlarged and underwent either surgical excision (n = 65), repeat core biopsy (n = 9), or imaging follow-up (n = 9). The incidence of atypia, in situ or invasive malignancy was 0/83 (0%). Two enlarging FAs were subsequently surgically diagnosed as benign phyllodes tumors (PT). Malignancy in or adjacent to a core biopsied FA is rare. The risk of cancer in a growing FA is even rarer; none were present in our series. FAs with abnormal epithelial abnormalities require excision. Otherwise, FAs without epithelial abnormality diagnosed by core biopsy need no specific follow-up considering the negligible incidence of conversion to malignancy. The breast interventionalist must know how to manage discordant pathology results

  7. CFD analysis of cloud cavitation on three tip-modified propellers with systematically varied tip geometry

    DEFF Research Database (Denmark)

    Shin, K. W.; Andersen, Poul

    2015-01-01

    The blade tip loading is often reduced as an effort to restrain sheet and tip vortex cavitation in the design of marine propellers. This CFD analysis demonstrates that an excessive reduction of the tip loading can cause cloud cavitation responsible for much of noise and surface erosion. Detached...

  8. Cryopreservation of chayote (Sechium edule JACQ.SW.) zygotic embryos and shoot-tips from in vitroplantlets

    OpenAIRE

    Abdelnour-Esquivel, Ana; Engelmann, Florent

    2002-01-01

    This paper presents the development of cryopreservation protocols for zygotic embryos and apices of chayote (Sechium edule Jacq. Sw.), a tropical plant species with recalcitrant seeds. Zygotic embryos of two cultivars, Ccocro negro (CN) and Claudio (Cl) could withstand cryopreservation, with survival percentages of 10 and 30 %, after desiccation to 23 and 19 % moisture content (fresh weight basis), respectively. Apices sampled on in vitro plantlets of cultivars Cl, 13 and JM we...

  9. Influence of Photo period and Gamma Irradiation on Shoot Development and Chemical Composition of Yucca elephantipes Regel Plant in Vitro

    International Nuclear Information System (INIS)

    El-Khateeb, M.A.; El-Sharnouby, M.E.; Ragab, E.A.

    2008-01-01

    In-Vitro propagated plant lets of Yucca elephantipes were placed under different photo periods (24/0, 16/8, and 0/24 L/D) for two months after cultured on MS medium supplemented with 40 g/l sucrose. Growing explants of Yucca elephantipes cultured on MS medium placed under photo period 24/0 L/D gave the highest shoot length and best proliferation than other treatments especially in subculture 3. Exposure to gamma irradiation at doses 0.0, 5 ,10, 20 and 40 Gy, and placed on the same conditions .Irradiated plantlets exhibited changes in shoot growth especially on photo period at 16/8 L/D than others, also with gamma irradiation at dose 20 Gy. Using gamma irradiation at level of 20 and 40 Gy stimulated both leaf shape and thickness of stem. The contents of total phenol, total saponin and some unsap contents were increased with increasing gamma irradiation

  10. Crack Tip Mechanics in Distortion Gradient Plasticity

    DEFF Research Database (Denmark)

    Fuentes-Alonso, Sandra; Martínez Pañeda, Emilio

    2017-01-01

    Gradient Plasticity (DGP), the influence on crack tip mechanics of DGP's distinguishing features that entail superior modelling capabilities has not been investigated yet. In this work crack tip fields are thoroughly examined by implementing the higher order theory of DGP in an implicit finite element...

  11. Jagged gives endothelial tip cells an edge.

    Science.gov (United States)

    Suchting, Steven; Eichmann, Anne

    2009-06-12

    Sprouting blood vessels have tip cells that lead and stalk cells that follow. Benedito et al. (2009) now show that competition between endothelial cells for the tip position is regulated by glycosylation of Notch receptors and by the opposing actions of the Notch ligands Jagged1 and Delta-like 4.

  12. Twelve Tips for Effective Electronic Presentation.

    Science.gov (United States)

    Crosby, Joy

    1994-01-01

    Offers 12 tips for effective electronic presentation. This article is intended for readers who may be considering using electronic presentation for the first time. Offers reasons for its popularity and occasions when it may be used. The tips offer assistance in the design and presentation of electronic material. (LZ)

  13. Melting ice, growing trade?

    Directory of Open Access Journals (Sweden)

    Sami Bensassi

    2016-05-01

    Full Text Available Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR. Two key constraints on the future viability of the NSR pertain to bathymetry and the future evolution of the sea ice cover. Climate model projections of future sea ice conditions throughout the rest of the century suggest that even under the most “aggressive” emission scenario, increases in international trade between Europe and Asia will be very low. The large inter-annual variability of weather and sea ice conditions in the route, the Russian toll imposed for transiting the NSR, together with high insurance costs and scarce loading/unloading opportunities, limit the use of the NSR. We show that even if these obstacles are removed, the duration of the opening of the NSR over the course of the century is not long enough to offer a consequent boost to international trade at the macroeconomic level.

  14. Early warning of climate tipping points

    Science.gov (United States)

    Lenton, Timothy M.

    2011-07-01

    A climate 'tipping point' occurs when a small change in forcing triggers a strongly nonlinear response in the internal dynamics of part of the climate system, qualitatively changing its future state. Human-induced climate change could push several large-scale 'tipping elements' past a tipping point. Candidates include irreversible melt of the Greenland ice sheet, dieback of the Amazon rainforest and shift of the West African monsoon. Recent assessments give an increased probability of future tipping events, and the corresponding impacts are estimated to be large, making them significant risks. Recent work shows that early warning of an approaching climate tipping point is possible in principle, and could have considerable value in reducing the risk that they pose.

  15. Parents and Educators [Tip Card

    Science.gov (United States)

    US Department of Homeland Security, 2011

    2011-01-01

    Stop.Think.Connect. is a national public awareness campaign aimed at increasing the understanding of cyber threats and empowering the American public to be safer and more secure online. The Campaign's main objective is to help individuals become more aware of growing cyber threats and arm them with the tools to protect themselves, their families,…

  16. Insights From Flutracking: Thirteen Tips to Growing a Web-Based Participatory Surveillance System.

    Science.gov (United States)

    Dalton, Craig; Carlson, Sandra; Butler, Michelle; Cassano, Daniel; Clarke, Stephen; Fejsa, John; Durrheim, David

    2017-08-17

    Flutracking is a weekly Web-based survey of influenza-like illness (ILI) in Australia that has grown from 400 participants in 2006 to over 26,000 participants every week in 2016. Flutracking monitors both the transmission and severity of ILI across Australia by documenting symptoms (cough, fever, and sore throat), time off work or normal duties, influenza vaccination status, laboratory testing for influenza, and health seeking behavior. Recruitment of Flutrackers commenced via health department and other organizational email systems, and then gradually incorporated social media promotion and invitations from existing Flutrackers to friends to enhance participation. Invitations from existing participants typically contribute to over 1000 new participants each year. The Flutracking survey link was emailed every Monday morning in winter and took less than 10 seconds to complete. To reduce the burden on respondents, we collected only a minimal amount of demographic and weekly data. Additionally, to optimize users' experiences, we maintained a strong focus on "obvious design" and repeated usability testing of naïve and current participants of the survey. In this paper, we share these and other insights on recruitment methods and user experience principles that have enabled Flutracking to become one of the largest online participatory surveillance systems in the world. There is still much that could be enhanced in Flutracking; however, we believe these principles could benefit others developing similar online surveillance systems. ©Craig Dalton, Sandra Carlson, Michelle Butler, Daniel Cassano, Stephen Clarke, John Fejsa, David Durrheim. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 17.08.2017.

  17. The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment.

    Science.gov (United States)

    Allen, Peter M; Latham, Keziah; Mann, David L; Ravensbergen, Rianne H J C; Myint, Joy

    2016-01-01

    The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle, while standing, toward a regulation target placed at the end of a 10 m shooting range. Cambridge simulation glasses were used to simulate six different levels of VI. Visual acuity (VA) and contrast sensitivity (CS) were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual's average score in every level of simulated VI and normalizing this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving 'expected' or 'below expected' shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR) is conservative, maximizing the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not actually have an impairment that impacts performance in the sport. An

  18. The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting With Vision Impairment

    Directory of Open Access Journals (Sweden)

    Peter M Allen

    2016-11-01

    Full Text Available The aim of this study was to investigate the level of vision impairment that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI shooting. Nineteen international-level shooters without vision impairment took part in the study. Participants shot an air rifle, while standing, towards a regulation target placed at the end of a 10m shooting range. Cambridge simulation glasses were used to simulate six different levels of vision impairment. Visual acuity (VA and contrast sensitivity (CS were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual’s average score in every level of simulated vision impairment and normalising this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic (ROC curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving ‘expected’ or ‘below expected’ shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR is conservative, maximising the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not

  19. Transcaval TIPS in patients with failed revision of occluded previous TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Chang Kyu; Kim, Yong Joo; Shin, Tae Beom; Park, Hyo Yong; Kim, Tae Hun; Kang, Duk Sik [Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2001-12-01

    To determine the feasibility of transcaval transjugular intrahepatic portosystemic shunt (TIPS) in patients with occluded previous TIPS. Between February 1996 and December 2000 we performed five transcaval TIPS procedures in four patients with recurrent gastric cardiac variceal bleeding. All four had occluded TIPS, which was between the hepatic and portal vein. The interval between initial TIPS placement and revisional procedures with transcaval TIPS varied between three and 31 months; one patient underwent transcaval TIPS twice, with a 31-month interval. After revision of the occluded shunt failed, direct cavoportal puncture at the retrohepatic segment of the IVC was attempted. Transcaval TIPS placement was technically successful in all cases. In three, tractography revealed slight leakage of contrast materials into hepatic subcapsular or subdiaphragmatic pericaval space. There was no evidence of propagation of extravasated contrast materials through the retroperitoneal space or spillage into the peritoneal space. After the tract was dilated by a bare stent, no patient experienced trans-stent bleeding and no serious procedure-related complications occurred. After successful shunt creation, variceal bleeding ceased in all patients. Transcaval TIPS placement is an effective and safe alternative treatment in patients with occluded previous TIPS and no hepatic veins suitable for new TIPS.

  20. Handgun Acquisitions in California After Two Mass Shootings.

    Science.gov (United States)

    Studdert, David M; Zhang, Yifan; Rodden, Jonathan A; Hyndman, Rob J; Wintemute, Garen J

    2017-05-16

    Mass shootings are common in the United States. They are the most visible form of firearm violence. Their effect on personal decisions to purchase firearms is not well-understood. To determine changes in handgun acquisition patterns after the mass shootings in Newtown, Connecticut, in 2012 and San Bernardino, California, in 2015. Time-series analysis using seasonal autoregressive integrated moving-average (SARIMA) models. California. Adults who acquired handguns between 2007 and 2016. Excess handgun acquisitions (defined as the difference between actual and expected acquisitions) in the 6-week and 12-week periods after each shooting, overall and within subgroups of acquirers. In the 6 weeks after the Newtown and San Bernardino shootings, there were 25 705 (95% prediction interval, 17 411 to 32 788) and 27 413 (prediction interval, 15 188 to 37 734) excess acquisitions, respectively, representing increases of 53% (95% CI, 30% to 80%) and 41% (CI, 19% to 68%) over expected volume. Large increases in acquisitions occurred among white and Hispanic persons, but not among black persons, and among persons with no record of having previously acquired a handgun. After the San Bernardino shootings, acquisition rates increased by 85% among residents of that city and adjacent neighborhoods, compared with 35% elsewhere in California. The data relate to handguns in 1 state. The statistical analysis cannot establish causality. Large increases in handgun acquisitions occurred after these 2 mass shootings. The spikes were short-lived and accounted for less than 10% of annual handgun acquisitions statewide. Further research should examine whether repeated shocks of this kind lead to substantial increases in the prevalence of firearm ownership. None.

  1. Growing Galaxies Gently

    Science.gov (United States)

    2010-10-01

    New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the 14 October issue of the journal Nature. The first galaxies formed well before the Universe was one billion years old and were much smaller than the giant systems - including the Milky Way - that we see today. So somehow the average galaxy size has increased as the Universe has evolved. Galaxies often collide and then merge to form larger systems and this process is certainly an important growth mechanism. However, an additional, gentler way has been proposed. A European team of astronomers has used ESO's Very Large Telescope to test this very different idea - that young galaxies can also grow by sucking in cool streams of the hydrogen and helium gas that filled the early Universe and forming new stars from this primitive material. Just as a commercial company can expand either by merging with other companies, or by hiring more staff, young galaxies could perhaps also grow in two different ways - by merging with other galaxies or by accreting material. The team leader, Giovanni Cresci (Osservatorio Astrofisico di Arcetri) says: "The new results from the VLT are the first direct evidence that the accretion of pristine gas really happened and was enough to fuel vigorous star formation and the growth of massive galaxies in the young Universe." The discovery will have a major impact on our understanding of the evolution of the Universe from the Big Bang to the present day. Theories of galaxy formation and evolution may have to be re-written. The group began by selecting three very distant galaxies to see if they could find evidence

  2. The tipping point: A mathematical model for the profit-driven abandonment of restaurant tipping

    Science.gov (United States)

    Clifton, Sara M.; Herbers, Eileen; Chen, Jack; Abrams, Daniel M.

    2018-02-01

    The custom of voluntarily tipping for services rendered has gone in and out of fashion in America since its introduction in the 19th century. Restaurant owners that ban tipping in their establishments often claim that social justice drives their decisions, but we show that rational profit-maximization may also justify the decisions. Here, we propose a conceptual model of restaurant competition for staff and customers, and we show that there exists a critical conventional tip rate at which restaurant owners should eliminate tipping to maximize profits. Because the conventional tip rate has been increasing steadily for the last several decades, our model suggests that restaurant owners may abandon tipping en masse when that critical tip rate is reached.

  3. In vitro binding of germanium to proteins of rice shoots

    International Nuclear Information System (INIS)

    Matsumoto, Hideaki; Takahashi, Eiichi

    1976-01-01

    The possibility of in vitro binding between proteins of rice shoots and germanium (Ge) was investigated. The proteins in mixtures of aqueous extracts of rice shoots and radioactive germanium ( 68 GeO 2 ) were fractionated. The binding of radioactivity to the proteins was observed even after 5 successive fractionation steps from the original mixtures. At the final fractionation step using polyacrylamide gel electrophoresis, a constant proportionality between protein concentration and associated radioactivity was found in most samples although not all. These results indicate that the binding of 68 Ge to proteins is not due to the simple adsorption by proteins. (auth.)

  4. School shootings during 2013-2015 in the USA.

    Science.gov (United States)

    Kalesan, Bindu; Lagast, Kinan; Villarreal, Marcos; Pino, Elizabeth; Fagan, Jeffrey; Galea, Sandro

    2017-10-01

    Data on the factors associated with school shootings in the USA are limited. The public conversation has often suggested several factors that may be linked to these events, however with little empirical support. Aiming to fill this gap, we describe the characteristics of school shooting incidents in the USA between 2013 and 2015 and explore whether four factors that represent domains of firearm policy, educational policy and epidemiological risk factors for intentional firearm injuries-background check (BC) policies, per capita mental health expenditures (MHE), K-12 education expenditure (KEE) and urbanicity-were associated with school shootings during this period. We searched LexisNexis, a newspaper and broadcast media databases for school shooting incidents from 1 January 2013 to 31 December 2015. Presence of BC laws was extracted from legal information in LexisNexis. State-level covariates of per capita MHE (2013), KEE (2013) and urbanicity (2010) rates were obtained from publicly available data sources. We used negative binomial regression models accounting for clustering by state to explore unadjusted associations between the BC laws, state-level covariates and school shootings to report IRR and 95% CI. We documented 154 school shootings (35, 55 and 64 each year). In unadjusted models, BC for firearm purchase (IRR=0.55, 95% CI 0.39 to 0.76), ammunition purchase (IRR=0.11, 95% CI 0.05 to 0.27), log per capita MHE (IRR=0.58, 95% CI 0.37 to 0.90), log per-capita KEE (IRR=0.09, 9% CI 0.02 to 0.29) and urbanicity (IRR=0.97, 95% CI 0.96 to 0.99) were associated with school shooting. School shootings are less likely in states with BC laws, higher MHE and KEE, and with greater per cent urban population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Changes of antioxidative enzymes in Impatiens walleriana L. shoots in response to genetic transformation

    Directory of Open Access Journals (Sweden)

    Milošević Snežana

    2015-01-01

    Full Text Available Impatiens walleriana L. shoots were inoculated with Agrobacterium rhizogenes A4M70GUS and the effects of genetic transformation on the catalase (CAT, superoxide dismutase (SOD and peroxidase (POX activities in wounded region of stems and unwounded leaves were evaluated 10, 24, 240 and 720 hours after inoculation. Following Agrobacterum infection activities of plant antioxidative enzymes changed in a time-dependent manner indicating that dynamic processes occurred during plant-Agrobacterium interaction, plant cell transformation and formation of hairy roots. Appearance of hairy roots on wound sites of shoots was observed ten days after inoculation with A. rhizogenes and the root induction frequency was 100%. Among selected hairy root lines significant differences in growth rate and biomass production were observed and an average 3-fold increase in biomass production was observed for the best growing hairy root line compared with the untransformed roots. PCR analysis showed presence of uidA, rolB, rolC and rolD genes in all analyzed I. walleriana L. hairy root lines, while amplification fragment of rolA gene was detected in 83.3% transformed lines. Efficient transformation protocol for I. walleriana L described in this work offer possibilities to generate hairy root cultures for in vitro propagation of plant viruses. [Projekat Ministarstva nauke Republike Srbije, br. TR-31019

  6. Dealing with school shootings, violence: how Jonesboro and Denver hospitals met this new challenge to emergency preparedness.

    Science.gov (United States)

    1999-08-01

    Acts of violence at schools across the country committed by gun-wielding students in recent years have all too frequently, as we know by now, resulted in multiple casualties and widespread community grieving. Two of the shooting rampages noted in this report that attracted national and international media attention--one at West-side Middle School, Jonesboro, AR, on March 24, 1998, and the other at Columbine High School, Littleton, CO, on April 20, 1999--illustrate the importance of hospital preparedness and quick implementation of emergency disaster plans. In both instances, officials say their administrative, clinical, and security personnel were well prepared to handle the physical and emotional trauma caused by the tragedies. Meanwhile, a leading criminologist warns that the trend toward school violence likely will continue and provides tips for hospitals and their security directors.

  7. Tipping device for large components

    International Nuclear Information System (INIS)

    Guigon, J.P.; Beraudier, D.

    1984-01-01

    For large components machining as components of a pressurized water reactor, it is necessary to have means allowing to present them in a position determined with regard to the machine tool used. The aim of the invention is a tipping device which consists of a base resting on the ground, a support-table mounted on this base, moving in rotation with the aid of at least a pivot joint of which axis is horizontal and parallel to the table and a gear pivot allowing to get a very good precision for the orientation of the piece and a very good stability whatever the orientation may be. The output shaft pinion of the base meshes with a gear wheel segment fixed to the table structure. Safety straps fasten the table structure to the base, as they are secured by horizontal pins. The toe pins run in straight slot holes incorporated in base jaws. The table rotation may be controlled by a spring-loaded braking mechanism which acts on the pivot axis and can be released by a hydraulic jack. The hydraulic pressure is used to prevent motor operation, unless the brakes have been released [fr

  8. Tipping Points, Great and Small

    Science.gov (United States)

    Morrison, Foster

    2010-12-01

    The Forum by Jordan et al. [2010] addressed environmental problems of various scales in great detail, but getting the critical message through to the formulators of public policies requires going back to basics, namely, that exponential growth (of a population, an economy, or most anything else) is not sustainable. When have you heard any politician or economist from anywhere across the ideological spectrum say anything other than that more growth is essential? There is no need for computer models to demonstrate “limits to growth,” as was done in the 1960s. Of course, as one seeks more details, the complexity of modeling will rapidly outstrip the capabilities of both observation and computing. This is common with nonlinear systems, even simple ones. Thus, identifying all possible “tipping points,” as suggested by Jordan et al. [2010], and then stopping just short of them, is impractical if not impossible. The main thing needed to avoid environmental disasters is a bit of common sense.

  9. Involvements of PCD and changes in gene expression profile during self-pruning of spring shoots in sweet orange (Citrus sinensis).

    Science.gov (United States)

    Zhang, Jin-Zhi; Zhao, Kun; Ai, Xiao-Yan; Hu, Chun-Gen

    2014-10-13

    Citrus shoot tips abscise at an anatomically distinct abscission zone (AZ) that separates the top part of the shoots into basal and apical portions (citrus self-pruning). Cell separation occurs only at the AZ, which suggests its cells have distinctive molecular regulation. Although several studies have looked into the morphological aspects of self-pruning process, the underlying molecular mechanisms remain unknown. In this study, the hallmarks of programmed cell death (PCD) were identified by TUNEL experiments, transmission electron microscopy (TEM) and histochemical staining for reactive oxygen species (ROS) during self-pruning of the spring shoots in sweet orange. Our results indicated that PCD occurred systematically and progressively and may play an important role in the control of self-pruning of citrus. Microarray analysis was used to examine transcriptome changes at three stages of self-pruning, and 1,378 differentially expressed genes were identified. Some genes were related to PCD, while others were associated with cell wall biosynthesis or metabolism. These results strongly suggest that abscission layers activate both catabolic and anabolic wall modification pathways during the self-pruning process. In addition, a strong correlation was observed between self-pruning and the expression of hormone-related genes. Self-pruning plays an important role in citrus floral bud initiation. Therefore, several key flowering homologs of Arabidopsis and tomato shoot apical meristem (SAM) activity genes were investigated in sweet orange by real-time PCR and in situ hybridization, and the results indicated that these genes were preferentially expressed in SAM as well as axillary meristem. Based on these findings, a model for sweet orange spring shoot self-pruning is proposed, which will enable us to better understand the mechanism of self-pruning and abscission.

  10. PEMBELAJARAN LAY UP SHOOT MENGGUNAKAN MEDIA AUDIO VISUAL BASIC LAY UP SHOOT UNTUK MENINGKATKAN HASILBELAJAR LAY UP SHOOT PADA SISWA KELAS VIIIA SMP KANISIUS PATI TAHUN 2013/2014

    Directory of Open Access Journals (Sweden)

    Frendy Nurochwan Febryanto

    2015-01-01

    Full Text Available The purpose of this study was to determine the learning lay up shoot using basic audiovisual media shoot lay ups can improve learning outcomes shoot lay ups in class VIIIA Starch Canisius junior year 2013/2014 . This study uses Classroom Action Research ( CAR. The technique of collecting data through observation and assessment of learning outcomes shoot basketball lay up. Data analysis techniques used in this research is descriptive . At the end of the first cycle activity of teachers in teaching basic techniques lay up shoot using audio-visual media reaches 76.19%, whereas at the end of the first cycle of student activity during the learning process lay up shoot using audio-visualmediareaches78.57%. At the end of the second cycle of activity of teachers in teaching basic techniques lay up shoot using audio-visual media reaches 85.71%, whereas at the end of the second cycle of activity of students during the learning process lay up shoot using audio-visual media reaches 92.86%. Based on the results of the study it can be concluded that learning the lay-up shoot using basic audiovisual media shoot lay ups can improve student learning outcomes at Canisius junior class VIIIA Pati year 2013/2014.

  11. [Organization of mitochondria in the growing hyphae of Neurospora crassa].

    Science.gov (United States)

    Potapova, T V; Boĭtsova, L Iu; Golyshev, S A; Popinako, A V

    2013-01-01

    In vivo fluorescent labeling of mitochondria in Neurospora crassa showed the concentration of filamentous mitochondria within 30 μm of apex in growing hyphae. These mitochondrial assemblies propagated forward with the elongation of hyphae, split and segregated as the growing tip bifurcated and formed de novo when new branches formed farther away from the apex. The efficiency of the mitochondria concentration in the apical 30 μm zone is related to the growth rate and identical in hyphae cultivated in glucose- and sorbitol-containing media. The obtained data are discussed in connection with the behavior of microtubules in growing hyphae as well as with the electric heterogeneity of N. crassa hyphal apex described previously.

  12. TEM observations of crack tip: cavity interactions

    International Nuclear Information System (INIS)

    Horton, J.A.; Ohr, S.M.; Jesser, W.A.

    1981-01-01

    Crack tip-cavity interactions have been studied by performing room temperature deformation experiments in a transmission electron microscope on ion-irradiated type 316 stainless steel with small helium containing cavities. Slip dislocations emitted from a crack tip cut, sheared, and thereby elongated cavities without a volume enlargement. As the crack tip approached, a cavity volume enlargement occurred. Instead of the cavities continuing to enlarge until they touch, the walls between the cavities fractured. Fracture surface dimples do not correlate in size or density with these enlarged cavities

  13. A fasciclin-like arabinogalactan-protein (FLA mutant of Arabidopsis thaliana, fla1, shows defects in shoot regeneration.

    Directory of Open Access Journals (Sweden)

    Kim L Johnson

    Full Text Available BACKGROUND: The fasciclin-like arabinogalactan-proteins (FLAs are an enigmatic class of 21 members within the larger family of arabinogalactan-proteins (AGPs in Arabidopsis thaliana. Located at the cell surface, in the cell wall/plasma membrane, they are implicated in many developmental roles yet their function remains largely undefined. Fasciclin (FAS domains are putative cell-adhesion domains found in extracellular matrix proteins of organisms from all kingdoms, but the juxtaposition of FAS domains with highly glycosylated AGP domains is unique to plants. Recent studies have started to elucidate the role of FLAs in Arabidopsis development. FLAs containing a single FAS domain are important for the integrity and elasticity of the plant cell wall matrix (FLA11 and FLA12 and FLA3 is involved in microspore development. FLA4/SOS5 with two FAS domains and two AGP domains has a role in maintaining proper cell expansion under salt stressed conditions. The role of other FLAs remains to be uncovered. METHOD/PRINCIPAL FINDINGS: Here we describe the characterisation of a T-DNA insertion mutant in the FLA1 gene (At5g55730. Under standard growth conditions fla1-1 mutants have no obvious phenotype. Based on gene expression studies, a putative role for FLA1 in callus induction was investigated and revealed that fla1-1 has a reduced ability to regenerate shoots in an in vitro shoot-induction assay. Analysis of FLA1p:GUS reporter lines show that FLA1 is expressed in several tissues including stomata, trichomes, the vasculature of leaves, the primary root tip and in lateral roots near the junction of the primary root. CONCLUSION: The results of the developmental expression of FLA1 and characterisation of the fla1 mutant support a role for FLA1 in the early events of lateral root development and shoot development in tissue culture, prior to cell-type specification.

  14. Similarities of School Shootings in Rural and Small Town Communities.

    Science.gov (United States)

    Kidd, Scott T.; Meyer, Cheryl L.

    2002-01-01

    A study examined characteristics common among young offenders from rural communities who were involved in multiple-fatality school shootings. Data on six cases involving eight offenders revealed six common offender characteristics: verbal threats, peer rejection, interest in violent media, previous violent behavior, suicidal ideation, and violent…

  15. The Role of Leadership in Surviving a School Shooting

    Science.gov (United States)

    Brown, Carleton H.

    2018-01-01

    At a small rural middle school in the southern United States, two students murdered a teacher, four students, and injured 10 during a shooting spree. This case represents the lived experiences of a school principal, counselor, and community that survived the deadly rampage. The case highlights the challenges that school leaders may face such as…

  16. Opposite metabolic responses of shoots and roots to drought

    Czech Academy of Sciences Publication Activity Database

    Gargallo-Garriga, A.; Sardans, J.; Pérez-Trujillo, M.; Rivas-Ubach, A.; Oravec, Michal; Večeřová, Kristýna; Urban, Otmar; Jentsch, A.; Kreyling, J.; Beierkuhnlein, C.; Parella, T.; Penuelas, J.

    2014-01-01

    Roč. 4, č. 6829 (2014), s. 1-7 ISSN 2045-2322 Grant - others:AV ČR(CZ) M200871201 Institutional support: RVO:67179843 Keywords : shoot and roots * autotrophic and heterotrophic organs * environmental change * growth metabolism * water and nutirens Subject RIV: EH - Ecology, Behaviour Impact factor: 5.578, year: 2014

  17. Shoot and root biomass allocation and competitive hierarchies of ...

    African Journals Online (AJOL)

    Shoot and root biomass allocation and competitive hierarchies of four South African grass species on light, soil resources and cutting gradients. ... Aristida junciformis, produced nearly double the biomass of taller species such as Hyparrhenia hirta and Eragrostis curvula in the low-nutrient treatments, with the reverse being ...

  18. Thidiazuron-induced shoot organogenesis of Cleome viscosa (L ...

    African Journals Online (AJOL)

    MBA

    2014-02-26

    Feb 26, 2014 ... J. Vijayakumar1*, G. Shobana Rathi1, S. M. Bhuvaneshwari1, B. D. ... propagation through callus culture of C. viscosa (Anburaj et al., 2011a,b), micropropagation and shoot organo- genesis from different explants of Cleome spinosa .... Figure 1. Effect of MS basal medium strength (a) and and GA, (b).

  19. Immobilization of lead in shooting range soil using biochar from ...

    African Journals Online (AJOL)

    Spent mushroom substrate (SMS) was pyrolyzed at 450°C for 2 hours and characterized using elemental analyzer and Boehm titration. Shooting range soil was incubated with 2.5% w/w and 5.0% w/w of SMSB for four weeks and the soil were characterized on the elemental composition, pH, electric conductivity (EC) and ...

  20. Genetic relationship between plant growth, shoot and kernel sizes in ...

    African Journals Online (AJOL)

    Maize (Zea mays L.) ear vascular tissue transports nutrients that contribute to grain yield. To assess kernel heritabilities that govern ear development and plant growth, field studies were conducted to determine the combining abilities of parents that differed for kernel-size, grain-filling rates and shoot-size. Thirty two hybrids ...

  1. Status of cocoa swollen shoot virus disease in Nigeria

    African Journals Online (AJOL)

    SERVER

    African Journal of Biotechnology Vol. 6 (17), pp. 2054-2061, 5 September 2007. Available online at ... Plant Pathology Division, Cocoa Research Institute of Nigeria, P.M.B. 5244, Ibadan, Oyo State, Nigeria. Accepted 9 August, 2007 ... economic importance of the disease in Nigeria. Key words: Cocoa, cocoa swollen shoot ...

  2. School Violence: Reported School Shootings and Making Schools Safer

    Science.gov (United States)

    Duplechain, Rosalind; Morris, Robert

    2014-01-01

    This manuscript consists of three sections. Section one provides historical data on some 310 documented shootings that have taken place on school property within the United States. Section two discusses numerous risk factors associated with school shooters. Section three discusses numerous strategies for creating safe schools.

  3. Supplementary data: Mapping of shoot fly tolerance loci in sorghum ...

    Indian Academy of Sciences (India)

    Supplementary data: Mapping of shoot fly tolerance loci in sorghum using SSR markers. D. B. Apotikar, D. Venkateswarlu, R. B. Ghorade, R. M. Wadaskar, J. V. Patil and P. L. Kulwal. J. Genet. 90, 59–66. Table 1. List of SSR primers for sorghum. Primer code. Forward and reverse. Annealing temperature (°C). Product.

  4. Creating aesthetic, institutional and symbolic boundaries in fashion photo shoots

    NARCIS (Netherlands)

    van der Laan, E.; Kuipers, G.

    2016-01-01

    This study proposes a ‘bottom-up’, micro-sociological analysis of cultural production. Drawing on detailed observations of fashion photo shoots and interviews with fashion professionals in the Netherlands, we analyse how the division between ‘high’ (editorial) and ‘low’ (commercial) culture is

  5. The Oregon Shootings: Dealing with the Ethical Issues.

    Science.gov (United States)

    Smith, Saylor; Godbold, Jim; Carter, Paul

    1999-01-01

    Presents three short articles dealing with ethical issues facing the Thornton High School (Oregon) newspaper staff as they dealt with the aftermath of an incident in which an armed student allegedly entered the school cafeteria and began shooting. Discusses how the local newspaper covered the tragedy, and policies on dealing with reporting of…

  6. Adventitious shoot regeneration from leaf explants of the valuable ...

    African Journals Online (AJOL)

    Jane

    2011-08-10

    Aug 10, 2011 ... 2Department of Plant Biology and Plant Biotechnology, St. Joseph's College, Tiruchirappalli – 620 002, South India. Accepted 28 March, 2011 .... Effect of cytokinins (KN and BAP) alone or in combination with NAA on direct shoot bud regeneration from leaf explants of P. barbatus. Plant growth regulator ...

  7. Cocoa swollen shoot virus in Ghana: A review of diagnostic ...

    African Journals Online (AJOL)

    A quick and more reliable diagnostic method has for a long time been identified as one input that will greatly enhance the control of the cocoa swollen shoot disease in Ghana. Many diagnostic procedures have been developed for detecting the virus that causes the disease; yet, the detection of latent infections is still ...

  8. Shooting responses of potato ( Solanum tuberosum L.) varieties in ...

    African Journals Online (AJOL)

    A study was conducted in 2012 and 2013 at IRAD Bambui (Cameroon) to evaluate the rate of shooting in four improved IRAD potato varieties: Cipira, Tubira, Mafo and Bambui wonder. Liquid and solid media stocks prepared according to the International Potato Center (CIP)'s protocol were used. A randomized complete ...

  9. Genotype dependent callus induction and shoot regeneration in ...

    African Journals Online (AJOL)

    SERVER

    2007-07-04

    Jul 4, 2007 ... tems have been used for improvement of sunflower, but these techniques are mainly limited by the tissue culture response of commercial varieties (Nestares et al., 2002). In sunflower, reports on shoot regeneration from hypocotyls, cotyledons, leaves and meristematic tissues of young plantlets are available ...

  10. Adventitious shoot regeneration from leaf explants of the valuable ...

    African Journals Online (AJOL)

    The objective of this study was to develop an efficient protocol for adventitious shoot regeneration for Plectranthus barbatus Andrews using leaf explants. The explants were cultured on MS (Murashige and Skoog, 1962) medium containing various concentration of kinetin (KN), 6-benzylaminopurine (BAP) and thidiazuron ...

  11. Shoot- and root-borne cytokinin influences arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Cosme, Marco; Ramireddy, Eswarayya; Franken, Philipp; Schmülling, Thomas; Wurst, Susanne

    2016-10-01

    The arbuscular mycorrhizal (AM) symbiosis is functionally important for the nutrition and growth of most terrestrial plants. Nearly all phytohormones are employed by plants to regulate the symbiosis with AM fungi, but the regulatory role of cytokinin (CK) is not well understood. Here, we used transgenic tobacco (Nicotiana tabacum) with a root-specific or constitutive expression of CK-degrading CKX genes and the corresponding wild-type to investigate whether a lowered content of CK in roots or in both roots and shoots influences the interaction with the AM fungus Rhizophagus irregularis. Our data indicates that shoot CK has a positive impact on AM fungal development in roots and on the root transcript level of an AM-responsive phosphate transporter gene (NtPT4). A reduced CK content in roots caused shoot and root growth depression following AM colonization, while neither the uptake of phosphorus or nitrogen nor the root transcript levels of NtPT4 were significantly affected. This suggests that root CK may restrict the C availability from the roots to the fungus thus averting parasitism by AM fungi. Taken together, our study indicates that shoot- and root-borne CK have distinct roles in AM symbiosis. We propose a model illustrating how plants may employ CK to regulate nutrient exchange with the ubiquitous AM fungi.

  12. Training, Drills Pivotal in Mounting Response to Orlando Shooting.

    Science.gov (United States)

    Albert, Eric; Bullard, Timothy

    2016-08-01

    Emergency providers at Orlando Regional Medical Center in Orlando. FL, faced multiple challenges in responding to the worst mass shooting in U.S. history. As the scene of the shooting was only three blocks away from the hospital, there was little time to prepare when notified that victims would begin arriving shortly after 2 a.m. on June 12. Also, fears of a gunman near the hospital briefly put the ED on lock down. However, using the incident command system, the hospital was able to mobilize quickly, receiving 44 patients, nine of whom died shortly after arrival. Administrators note that recent training exercises geared toward a mass shooting event facilitated the response and probably saved lives. Patients arrived at the hospital in two waves, with the initial surge occurring right after the hooting took place around 2 a.m., and the second surge occurring about three hours later. At one point, more than 90 patients were in the ED, more than half for reasons unrelated to the shooting. Clinicians contended with a much higher than usual noise level while treating patients, making it hard to hear reports from EMS personnel. Also, treatment had to commence prior to identification for some patients who arrived unconscious or unable to speak. While surgeons and other key specialists were called into the hospital to address identified needs, administrators actually called hospital personnel to tell them not to come in unless they were notified. This prevented added management hurdles.

  13. Lead poisoning in shooting-range workers in Gauteng Province ...

    African Journals Online (AJOL)

    Background. Lead exposure constitutes a major public health concern globally. Relative to developed nations, lead exposure is understudied and poorly addressed in Africa, and there is a dearth of information available to inform lead poisoning prevention strategies, even in highrisk groups such as workers in shooting ...

  14. EPICORMIC SHOOTS INDUCTION AND ROOTING CUTTINGS OF Calophyllum brasiliense

    Directory of Open Access Journals (Sweden)

    Dagma Kratz

    2016-12-01

    Full Text Available Calophyllum brasiliense is present in a wide natural distribution range in Brazil and its monopodial growth, with a rectilinear stem and a moderately dense timber has attracted the attention from the logging industry in recent decades. In the meantime, the lack of efficient rescue and vegetative propagation methods of adult plants has been a narrowing condition for the selection of superior genotypes in breeding programs of the species. Therefore, we evaluate epicormic shoots induction methods and the rooting cuttings of 14 year-old Calophyllum brasiliense trees. From this scope, three methods of epicormic shoots induction were evaluated: coppicing, girdling and partial girdling. We evaluate the number of produced sprouts and the percentage of sprouted trees at 06, 12 and 15 months’ after the experiment installation. Results have indicated the feasibility of Calophyllum brasiliense vegetative rescue by cuttings method using epicormic shoots induced by coppicing and girdling. In contrast, partial girdling was not effective in epicormic shoots emission. Concerning adventitious roots, the sprouting technique had no influence in the rooting of cuttings, showing variation among the different stock plants.

  15. Plant regeneration through organogenesis and shoot proliferation in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... Effect of 2,4-D, NAA and BA (in MS medium) on Trichodesma indicum callus induction and shoot .... Structure/activity relationships of the fenotoxic potentcies of sixteen pyrrolizidine ... In vitro propagation of Cordia verbe- ...

  16. Experimental drought and heat can delay phenological development and reduce foliar and shoot growth in semiarid trees.

    Science.gov (United States)

    Adams, Henry D; Collins, Adam D; Briggs, Samuel P; Vennetier, Michel; Dickman, L Turin; Sevanto, Sanna A; Garcia-Forner, Núria; Powers, Heath H; McDowell, Nate G

    2015-11-01

    Higher temperatures associated with climate change are anticipated to trigger an earlier start to the growing season, which could increase the terrestrial C sink strength. Greater variability in the amount and timing of precipitation is also expected with higher temperatures, bringing increased drought stress to many ecosystems. We experimentally assessed the effects of higher temperature and drought on the foliar phenology and shoot growth of mature trees of two semiarid conifer species. We exposed field-grown trees to a ~45% reduction in precipitation with a rain-out structure ('drought'), a ~4.8 °C temperature increase with open-top chambers ('heat'), and a combination of both simultaneously ('drought + heat'). Over the 2013 growing season, drought, heat, and drought + heat treatments reduced shoot and needle growth in piñon pine (Pinus edulis) by ≥39%, while juniper (Juniperus monosperma) had low growth and little response to these treatments. Needle emergence on primary axis branches of piñon pine was delayed in heat, drought, and drought + heat treatments by 19-57 days, while secondary axis branches were less likely to produce needles in the heat treatment, and produced no needles at all in the drought + heat treatment. Growth of shoots and needles, and the timing of needle emergence correlated inversely with xylem water tension and positively with nonstructural carbohydrate concentrations. Our findings demonstrate the potential for delayed phenological development and reduced growth with higher temperatures and drought in tree species that are vulnerable to drought and reveal potential mechanistic links to physiological stress responses. Climate change projections of an earlier and longer growing season with higher temperatures, and consequent increases in terrestrial C sink strength, may be incorrect for regions where plants will face increased drought stress with climate change. © 2015 John Wiley & Sons Ltd.

  17. Characterization of somatic embryogenesis initiated from the Arabidopsis shoot apex.

    Science.gov (United States)

    Kadokura, Satoshi; Sugimoto, Kaoru; Tarr, Paul; Suzuki, Takamasa; Matsunaga, Sachihiro

    2018-04-28

    Somatic embryogenesis is one of the best examples of the remarkable developmental plasticity of plants, in which committed somatic cells can dedifferentiate and acquire the ability to form an embryo and regenerate an entire plant. In Arabidopsis thaliana, the shoot apices of young seedlings have been reported as an alternative tissue source for somatic embryos (SEs) besides the widely studied zygotic embryos taken from siliques. Although SE induction from shoots demonstrates the plasticity of plants more clearly than the embryo-to-embryo induction system, the underlying developmental and molecular mechanisms involved are unknown. Here we characterized SE formation from shoot apex explants by establishing a system for time-lapse observation of explants during SE induction. We also established a method to distinguish SE-forming and non-SE-forming explants prior to anatomical SE formation, enabling us to identify distinct transcriptome profiles of these two explants at SE initiation. We show that embryonic fate commitment takes place at day 3 of SE induction and the SE arises directly, not through callus formation, from the base of leaf primordia just beside the shoot apical meristem (SAM), where auxin accumulates and shoot-root polarity is formed. The expression domain of a couple of key developmental genes for the SAM transiently expands at this stage. Our data demonstrate that SE-forming and non-SE-forming explants share mostly the same transcripts except for a limited number of embryonic genes and root genes that might trigger the SE-initiation program. Thus, SE-forming explants possess a mixed identity (SAM, root and embryo) at the time of SE specification. Copyright © 2018. Published by Elsevier Inc.

  18. GPU based numerical simulation of core shooting process

    Directory of Open Access Journals (Sweden)

    Yi-zhong Zhang

    2017-11-01

    Full Text Available Core shooting process is the most widely used technique to make sand cores and it plays an important role in the quality of sand cores. Although numerical simulation can hopefully optimize the core shooting process, research on numerical simulation of the core shooting process is very limited. Based on a two-fluid model (TFM and a kinetic-friction constitutive correlation, a program for 3D numerical simulation of the core shooting process has been developed and achieved good agreements with in-situ experiments. To match the needs of engineering applications, a graphics processing unit (GPU has also been used to improve the calculation efficiency. The parallel algorithm based on the Compute Unified Device Architecture (CUDA platform can significantly decrease computing time by multi-threaded GPU. In this work, the program accelerated by CUDA parallelization method was developed and the accuracy of the calculations was ensured by comparing with in-situ experimental results photographed by a high-speed camera. The design and optimization of the parallel algorithm were discussed. The simulation result of a sand core test-piece indicated the improvement of the calculation efficiency by GPU. The developed program has also been validated by in-situ experiments with a transparent core-box, a high-speed camera, and a pressure measuring system. The computing time of the parallel program was reduced by nearly 95% while the simulation result was still quite consistent with experimental data. The GPU parallelization method can successfully solve the problem of low computational efficiency of the 3D sand shooting simulation program, and thus the developed GPU program is appropriate for engineering applications.

  19. Sleep Tips: 7 Steps to Better Sleep

    Science.gov (United States)

    ... turn every night. Consider simple tips for better sleep, from setting a sleep schedule to including physical activity in your daily ... factors that can interfere with a good night's sleep — from work stress and family responsibilities to unexpected ...

  20. Diabetes Prevention: 5 Tips for Taking Control

    Science.gov (United States)

    ... Consider the latest diabetes prevention tips from the American Diabetes Association. There are many benefits to regular physical activity. ... if diabetes testing is appropriate for you. The American Diabetes Association recommends blood glucose screening if: You're age ...

  1. Tips to Help You Get Active

    Science.gov (United States)

    ... A Step in the Right Direction Tips to Help You Get Active View or Print All Sections ... and quality of life. Being more active may help you manage your weight. Starting Physical Activity Healthy ...

  2. Brain Injury Safety Tips and Prevention

    Science.gov (United States)

    ... submit" name="commit" type="submit" value="Submit" /> Brain Injury Safety Tips and Prevention Recommend on Facebook ... not grass or dirt. More HEADS UP Video: Brain Injury Safety and Prevention frame support disabled and/ ...

  3. Tips for Teens with Diabetes: About Diabetes

    Science.gov (United States)

    National Diabetes Education Program (NDEP), 2010

    2010-01-01

    Diabetes is a serious disease. It means that one's blood glucose, also called blood sugar, is too high. Having too much glucose in a person's blood is not healthy. This paper offers tips for managing diabetes.

  4. Daily Tips for Good Oral Hygiene

    Science.gov (United States)

    ... this article Daily Tips for Good Oral Hygiene Bacteria can live in your mouth in the form of plaque, causing cavities and gingivitis, which can lead to periodontal (gum) disease. In order to keep your mouth ...

  5. Impetigo: Tips for Treatment and Prevention

    Science.gov (United States)

    ... DO Videos Contact Close ‹ Back to Healthy Living Impetigo: Tips for Treatment and Prevention The symptoms of ... to other parts of their bodies. Causes of Impetigo Impetigo usually affects preschool and school-aged children, ...

  6. Can't sleep? Try these tips

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000853.htm Can't sleep? Try these tips To use the ... you get the rest you need. What you can do Some people have trouble falling asleep. Others ...

  7. Four Medication Safety Tips for Older Adults

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates 4 Medication Safety Tips for Older Adults Share Tweet ... you are experiencing could be due to medications. 4. Review Medications with Your Health Care Provider Ideally, ...

  8. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Weekend Warriors expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are ... skiing! Be Mindful of Time Spent in the Sun, Regardless of the Season If possible, ski early ...

  9. 6 Tips: IBS and Complementary Health Practices

    Science.gov (United States)

    ... health practice for IBS, here are 6 tips: Hypnotherapy (hypnosis). This practice involves the power of suggestion by ... IBS. According to reviews of the scientific literature, hypnotherapy may be a helpful treatment for managing IBS ...

  10. Compressor airfoil tip clearance optimization system

    Science.gov (United States)

    Little, David A.; Pu, Zhengxiang

    2015-08-18

    A compressor airfoil tip clearance optimization system for reducing a gap between a tip of a compressor airfoil and a radially adjacent component of a turbine engine is disclosed. The turbine engine may include ID and OD flowpath boundaries configured to minimize compressor airfoil tip clearances during turbine engine operation in cooperation with one or more clearance reduction systems that are configured to move the rotor assembly axially to reduce tip clearance. The configurations of the ID and OD flowpath boundaries enhance the effectiveness of the axial movement of the rotor assembly, which includes movement of the ID flowpath boundary. During operation of the turbine engine, the rotor assembly may be moved axially to increase the efficiency of the turbine engine.

  11. Tips for Older Dietary Supplement Users

    Science.gov (United States)

    ... Information for Consumers Tips for Older Dietary Supplement Users Share Tweet Linkedin Pin it More sharing options ... site are provided as a service to our users and do not represent FDA endorsement of these ...

  12. The transjugular intrahepatic portosystemic shunt (TIPS)

    International Nuclear Information System (INIS)

    Owen, A.R.; Stanley, A.J.; Vijayananthan, A.; Moss, J.G.

    2009-01-01

    The creation of an intrahepatic portosystemic shunt via a transjugular approach (TIPS) is an interventional radiological procedure used to treat the complications of portal hypertension. TIPS insertion is principally indicated to prevent or arrest variceal bleeding when medical or endoscopic treatments fail, and in the management refractory ascites. This review discusses the development and execution of the technique, with focus on its clinical efficacy. Patient selection, imaging surveillance, revision techniques, and complications are also discussed.

  13. The transjugular intrahepatic portosystemic shunt (TIPS)

    Energy Technology Data Exchange (ETDEWEB)

    Owen, A.R. [Department of Radiology, Austin Health, Heidelberg, Melbourne (Australia)], E-mail: andrewowen@doctors.org.uk; Stanley, A.J. [Department of Gastroenterology, Glasgow Royal Infirmary, Glasgow (United Kingdom); Vijayananthan, A. [Department of Biomedical Imaging, University of Malaya, Kuala Lumpur (Malaysia); Moss, J.G. [Department of Radiology, Gartnavel General Hospital, Glasgow (United Kingdom)

    2009-07-15

    The creation of an intrahepatic portosystemic shunt via a transjugular approach (TIPS) is an interventional radiological procedure used to treat the complications of portal hypertension. TIPS insertion is principally indicated to prevent or arrest variceal bleeding when medical or endoscopic treatments fail, and in the management refractory ascites. This review discusses the development and execution of the technique, with focus on its clinical efficacy. Patient selection, imaging surveillance, revision techniques, and complications are also discussed.

  14. PRODUCTION OF THE NEW ANTIMALARIAL DRUG ARTEMISININ IN SHOOT CULTURES OF ARTEMISIA-ANNUA L

    NARCIS (Netherlands)

    WOERDENBAG, HJ; LUERS, JFJ; VANUDEN, W; PRAS, N; MALINGRE, TM; ALFERMANN, AW

    From aseptically grown Artemisia annua plantlets, shoot cultures were initiated. Using different concentrations of auxine, cytokinine and sucrose, a suitable culture medium was developed, with respect to the growth of the shoots and their artemisinin accumulation. Nitrate concentration and

  15. Superconducting phase transition in STM tips

    Energy Technology Data Exchange (ETDEWEB)

    Eltschka, Matthias; Jaeck, Berthold; Assig, Maximilian; Etzkorn, Markus; Ast, Christian R. [Max Planck Institute for Solid State Research, Stuttgart (Germany); Kern, Klaus [Max Planck Institute for Solid State Research, Stuttgart (Germany); Ecole Polytechnique Federale de Lausanne (Switzerland)

    2015-07-01

    The superconducting properties of systems with dimensions comparable to the London penetration depth considerably differ from macroscopic systems. We have studied the superconducting phase transition of vanadium STM tips in external magnetic fields. Employing Maki's theory we extract the superconducting parameters such as the gap or the Zeeman splitting from differential conductance spectra. While the Zeeman splitting follows the theoretical description of a system with s=1/2 and g=2, the superconducting gaps as well as the critical fields depend on the specific tip. For a better understanding of the experimental results, we solve a one dimensional Usadel equation modeling the superconducting tip as a cone with the opening angle α in an external magnetic field. We find that only a small region at the apex of the tip is superconducting in high magnetic fields and that the order of the phase transition is directly determined by α. Further, the spectral broadening increases with α indicating an intrinsic broadening mechanism due to the conical shape of the tip. Comparing these calculations to our experimental results reveals the order of the superconducting phase transition of the STM tips.

  16. The Effect of High School Shootings on Schools and Student Performance

    OpenAIRE

    Louis-Philippe Beland; Dongwoo Kim

    2015-01-01

    We analyze how fatal shootings in high schools affect schools and students using data from shooting databases, school report cards, and the Common Core of Data. We examine schools’ test scores, enrollment, and number of teachers, as well as graduation, attendance, and suspension rates at schools that experienced a shooting, employing a difference-in-differences strategy that uses other high schools in the same district as the comparison group. Our findings suggest that homicidal shootings s...

  17. Heterologous Expression of Panax ginseng PgTIP1 Confers Enhanced Salt Tolerance of Soybean Cotyledon Hairy Roots, Composite, and Whole Plants

    Directory of Open Access Journals (Sweden)

    Jing An

    2017-07-01

    Full Text Available The Panax ginseng TIP gene PgTIP1 was previously demonstrated to have high water channel activity by its heterologous expression in Xenopus laevis oocytes and in yeast; it also plays a significant role in growth of PgTIP1-transgenic Arabidopsis plants under favorable conditions and has enhanced tolerance toward salt and drought treatment. In this work, we first investigated the physiological effects of heterologous PgTIP1 expression in soybean cotyledon hairy roots or composite plants mediated by Agrobacterium rhizogenes toward enhanced salt tolerance. The PgTIP1-transgenic soybean plants mediated by the pollen tube pathway, represented by the lines N and J11, were analyzed at the physiological and molecular levels for enhanced salt tolerance. The results showed that in terms of root-specific heterologous expression, the PgTIP1-transformed soybean cotyledon hairy roots or composite plants displayed superior salt tolerance compared to the empty vector-transformed ones according to the mitigatory effects of hairy root growth reduction, drop in leaf RWC, and rise in REL under salt stress. Additionally, declines in K+ content, increases in Na+ content and Na+/K+ ratios in the hairy roots, stems, or leaves were effectively alleviated by PgTIP1-transformation, particularly the stems and leaves of composite soybean plants. At the whole plant level, PgTIP1-trasgenic soybean lines were found to possess stronger root vigor, reduced root and leaf cell membrane damage, increased SOD, POD, CAT, and APX activities, steadily increased leaf Tr, RWC, and Pn values, and smaller declines in chlorophyll and carotenoid content when exposed to salt stress compared to wild type. Moreover, the distribution patterns of Na+, K+, and Cl- in the roots, stems, and leaves of salt-stressed transgenic plants were readjusted, in that the absorbed Na+ and Cl- were mainly restricted to the roots to reduce their transport to the shoots, and the transport of root-absorbed K+ to the

  18. Morphological Evaluation of Shoots Regenerated from Hygromycin-Resistant Rice Callus (cv IACuba-28

    Directory of Open Access Journals (Sweden)

    Maylin Pérez Bernal

    2007-01-01

    Full Text Available An evaluation system based on the morphological characteristics of regenerated hygromycin-resistant rice callus shoots was established for correlating such characteristics with shoot viability on hygromycin. Embryogenic rice calli were transformed by Agrobacterium tumefaciens (EHA105/ pCAMBIA1300, containing the hygromycin-phosphotransferase gene as selection marker. After two weeks on selection medium, hygromycin-resistant calli were transferred to regeneration medium. Regenerated shoots were extracted every 5 days (over a 30-day period and classified into three classes according to their morphological structure: class I: vigorous shoot having typical bipolar structure; class II: shoot having small root compared to apical length, or shoot without roots; class III: shoots having an abnormal appearance, such as malformed leaves or albinism. Individualised shoots were transferred to MS medium containing hygromycin for evaluating their resistance to antibiotics. A relationship was observed between regenerated shoots’ morphological characteristics and the percentage of shoots’ viability on hygromycin. Class I prevailed at early shoot extraction and was the most resistant to hygromycin. Drastic class I reduction was found with later shoot extraction, whilst classes II and III became increased. Likewise, shoot viability became radically reduced on MS medium containing hygromycin. This result might be applied for improving efficiency regarding obtaining transgenic rice plants, taking into account the best time for obtaining high percentages of hygromycin-resistant shoots having the best morphological characteristics.

  19. The Effect of High School Shootings on Schools and Student Performance

    Science.gov (United States)

    Beland, Louis-Philippe; Kim, Dongwoo

    2016-01-01

    We analyze how fatal shootings in high schools affect schools and students using data from shooting databases, school report cards, and the Common Core of Data. We examine schools' test scores, enrollment, number of teachers, graduation, attendance, and suspension rates at schools that experienced a shooting, employing a difference-in-differences…

  20. A Case Study of Two Chicago Suburban High Schools: Practices to Avoid a School Shooting

    Science.gov (United States)

    Connelly, Kevin G.

    2017-01-01

    Throughout 2015, there have been 52 school shootings within the United States that have left 30 individuals dead and another 53 injured (Reuters-USA, 2015). Since Friday, December 14, 2012, the date of the Sandy Hook Elementary School shooting, in which 26 people lost their lives, there has been on average one school shooting per week. It is…

  1. TIPS Evaluation Project Retrospective Study: Wave 1 and 2.

    Science.gov (United States)

    Hubbard, Susan M.; Mulvey, Kevin P.

    2003-01-01

    Measured substance abuse treatment professionals' knowledge, attitudes, and practices regarding the Treatment Improvement Protocol (TIP) series and the 28 TIPs. Results for 3,267 respondents in wave 1 and 1,028 in wave 2 indicate that almost half of all professionals were aware of the TIPs. Attitudes toward TIPs were positive, but professionals…

  2. Growing container seedlings: Three considerations

    Science.gov (United States)

    Kas Dumroese; Thomas D. Landis

    2015-01-01

    The science of growing reforestation and conservation plants in containers has continually evolved, and three simple observations may greatly improve seedling quality. First, retaining stock in its original container for more than one growing season should be avoided. Second, strongly taprooted species now being grown as bareroot stock may be good candidates...

  3. Deformation localization at the tips of shear fractures: An analytical approach

    Science.gov (United States)

    Misra, Santanu

    2011-04-01

    Mechanical heterogeneities are important features in rocks which trigger deformation localization in brittle, ductile or brittle-ductile modes during deformation. In a recent study Misra et al. (2009) have investigated these different processes of deformation localization at the tips of pre-existing planar shear fractures. The authors identified four mechanisms of deformation, ranging from brittle to ductile, operating at the crack tips. Mechanism A: brittle deformation is the dominant process that forms a pair of long tensile fractures at the two crack tips. Mechanism B: nature of deformation is mixed where the tensile fractures grow to a finite length with incipient plastic deformation at the tips. Mechanism C: mixed mode deformation characterized by dominating macro-scale shear bands, and short, opened-out tensile fissures. Mechanism D: localization of plastic bands in the form of a pair of shear bands at each tip without any discernible brittle fracturing. The transition of the mechanisms is a function of orientation ( α) of the crack with respect to the bulk compression direction and the finite length ( l) of the crack. The aim of this study is to present a theoretical analysis to account for the variability of deformation localization in the vicinity of pre-existing shear cracks considering an elastic-plastic rheological model. The analysis calculates the principal tensile stress ( σ1) and the second stress invariant ( I2) of the stress field at the fracture tip to explain the transition from Mechanism A (tensile fracturing) to Mechanism D (ductile strain). The results show that σ1 at the fracture tip increases non-linearly with increasing α and Ar (aspect ratio of the shear crack), and assumes a large value when α > 50 o, promoting tensile fractures. On the other hand, I2 is a maximum at α < 45°, resulting in nucleation of ductile shear bands.

  4. Plantlets from encapsulated shoot buds of Catalpa ovata G. Don

    Directory of Open Access Journals (Sweden)

    Halina Wysokińska

    2014-01-01

    Full Text Available Shoot buds isolated from in vitro shoot cultures of Catalpa ovata G. Don were encapsulated using 3% sodium alginate with sucrose (3% and 50 mM calcium chloride. The morphogenic response of encapsulated buds was affected by such factors, like composition of the media and the presence of growth regulators. The highest frequency of plantlet germination from encapsulated buds (70% within 4 weeks was obtained on Woody Plant medium (WP (Lloyd and McCown 1980 containing indole-3-butyric acid (IBA (1 mg/l. The process was substantially inhibited by cold-storage (4oC of encapsulated buds. In this case, the frequency response ranged from 3% to 22% dependent on storage period (28 or 42 days and the presence of the paraffin coat covering the alginate capsules. The plantlets developed from both unstored and stored encapsulated buds of C. ovata were transplanted to soil and grew in pots to phenotypically normal plants.

  5. Shoot water relations of mature black spruce families displaying a genotype × environment interaction in growth rate. III. Diurnal patterns as influenced by vapor pressure deficit and internal water status

    Science.gov (United States)

    John E. Major; Kurt H. Johnsen

    2001-01-01

    Pressure­volume curves were constructed and shoot water potentials measured for +20-year-old black spruce (Picea mariana (Mill.) BSP) trees from four full-sib families growing on a moist site and a dry site at the Petawawa Research Forest, Ontario, to determine whether differences in diurnal water relations traits were related to productivity. To...

  6. Mild Traumatic Brain Injury and Dynamic Simulated Shooting Performance

    Science.gov (United States)

    2016-02-01

    differences between tasks. All pairwise comparisons were adjusted with a Sidak correction for multiple comparisons. TLX scores 0 5 10 15 20 25 30 35...research at multiple sites. Specific to the question of MTBI-related balance, we recommend that future studies seek, when feasible, to quantify body sway...higher ratings of perceived workload. In addition, the alternate analyses yielded some preliminary evidence of shooting performance decrements

  7. Cytokinin Activity in Water-stressed Shoots 1

    Science.gov (United States)

    Itai, Chanan; Vaadia, Yoash

    1971-01-01

    Water stress applied to the plant shoot through enhanced evaporative demands reduced cytokinin activity in extracts of xylem exudate and leaves. This reduction resembled the changes in cytokinin activity caused by water stress applied to the root. Cytokinin activity in detached wilting leaves decreased rapidly. Recovery took place after several hours in a humid chamber. Experiments with 14C-kinetin indicated that the mechanism of the inactivation and its reversal involve a chemical transformation of the cytokinin molecule. PMID:16657585

  8. School Shooting : Threat Detection and Classification in Textual Leakage

    OpenAIRE

    Khan, Ajmal

    2013-01-01

    The continual occurrence of school shooting incidents underscores the need of taking preventive measures. Inductive measures of threat assessment have proved to be a bad strategy to solve the problem and new research is focusing on deductive approaches. Deductive threat assessment approaches are gaining ground and efforts are underway to mine text for automatic detection of threats in written text. Automatic detection and classification of threats in the digital world can help the decision ma...

  9. Reconstruction of the Tip-Surface Interaction Potential by Analysis of the Brownian Motion of an Atomic Force Microscope Tip

    NARCIS (Netherlands)

    Willemsen, O.H.; Kuipers, L.; van der Werf, Kees; de Grooth, B.G.; Greve, Jan

    2000-01-01

    The thermal movement of an atomic force microscope (AFM) tip is used to reconstruct the tip-surface interaction potential. If a tip is brought into the vicinity of a surface, its movement is governed by the sum of the harmonic cantilever potential and the tip-surface interaction potential. By

  10. Frosts during the growing season. Frequency of occurrence and effects on current energy forestry. Sommarfroster. Foerekomster och effekter paa befintliga energiskogsodlingar

    Energy Technology Data Exchange (ETDEWEB)

    Christersson, L; Fircks, H von; Perttu, K

    1984-01-01

    Frost during the summer is very common in Sweden. Two kinds of summer frosts exists; one is called advection frost which is caused by cold air coming down over the country from the north and the other is an inversion frost caused by long-wave radiation from the ground taking place during calm clear nights. In this way the air closest to the ground is cooled. Eleven experimental areas are described as regards prehistory, vegetation, frequency of summer frosts, and energy forestry tests in progress. The amount of frost injuries is reported. Differences in frost hardiness of fast growing Salix clones in the growing state have been demonstrated. The results support the idea that the formation of ice crystals inside the growing tissues always take place around -2 degree C and that this ice crystal formation damages the growing part of the shoot of all tested clones. A fast growing shoot of Salix species has a longer elongation zone and this explains why a fast-growing shoot is more severly damaged than a slowly growing one at the same frost temperature. If the different clones are in a growing state there are only small differences in the amount of frost damage. On the other hand, there are great differences between the clones in the capacity of the surviving lateral buds to sprout. This capacity is foremost seen in clones of the species Salix dasyclados. Two year older shoots of different Salix species have never been damaged by summer frost because summer frosts do not reach the elongating zone of these shoots. In conclusions measures are listed on how to prevent or decrease the injuries caused by summer frosts. With 21 refs.

  11. Micropropagation of chokeberry by in vitro axillary shoot proliferation.

    Science.gov (United States)

    Litwińczuk, Wojciech

    2013-01-01

    The black chokeberry-aronia (Aronia melanocarpa Elliot) is a shrub native to North America although nowadays well known in Eastern Europe. The fruits are regarded as the richest source of antioxidant phytonutrients among fruit crops and vegetables. Chokeberries can be easily propagated by seeds but this method is not recommended. Micropropagation is far more efficient than other conventional cloning methods like layering or softwood cuttings. Aronia clones are propagated in vitro through four- or three-stage method based on subculturing of shoot explants. The double diluted MS or full strength MS medium with elevated 50% Ca(2+) and Mg(2+) content are used in the initiation and proliferation chokeberry in vitro cultures, respectively. They are supplemented with 0.5-1.0 mg LBA, and 0.05 mg LIBA. The double-phase medium is recommended in the last passage before shoot rooting. The regenerated shoots could be rooted both in vitro on double diluted MS with 0.05 mg L(-1) IBA or in vivo in peat and perlite substrate and subsequently grown in the greenhouse.

  12. Optoelectronics applications in multimedia shooting training systems: SPARTAN

    Science.gov (United States)

    Glogowski, Tomasz; Hlosta, Pawel; Stepniak, Slawomir; Swiderski, Waldemar

    2017-10-01

    Multimedia shooting training systems are increasingly being used in the training of security staff and uniformed services. An advanced practicing-training system SPARTAN for simulation of small arms shooting has been designed and manufactured by Autocomp Management Ltd. and Military Institute of Armament Technology for the Polish Ministry of National Defence. SPARTAN is a stationary device designed to teach, monitor and evaluate the targeting of small arms and to prepare soldiers for: • firing the live ammunition at open ranges for combat targets and silhouettes • detection, classification and engagement of real targets upon different terrains, weather conditions and periods during the day • team work as a squad during the mission by using different types of arms • suitable reactions in untypical scenarios. Placed in any room the training set consists of: • the projection system that generates realistic 3D imaging of the battlefield (such as combat shooting range) in high-resolution • system that tracks weapons aiming points • sound system which delivers realistic mapping of acoustic surroundings • operator station with which the training is conducted and controlled • central processing unit based on PC computers equipped with specialist software realizing individual system functions • units of smart weapons equipped with radio communication modules, injection laser diodes and pneumatic reloading system. The system make possible training by firing in dynamic scenarios, using combat weapons and live ammunition against visible targets moving on a screen. The use of infrared camera for detecting the position of impact of a projectile.

  13. Energetic exploitation of vine shoot by gasification processes

    Energy Technology Data Exchange (ETDEWEB)

    Ganan, J.; Al-Kassir Abdulla, A. [Dpto. Ingenieria Quimica y Energetica, Escuela de Ingenierias Industriales, Universidad de Extremadura, Avda de Elvas s/n, E-06071 Badajoz (Spain); Cuerda Correa, E.M. [Dpto. Quimica Inorganica, Facultad de Ciencias, Universidad de Extremadura, Avda de Elvas s/n, E-06071 Badajoz (Spain); Macias-Garcia, A. [Dpto. Electronica e Ingenieria Electromecanica, Escuela de Ingenierias Industriales, Universidad de Extremadura, Avda de Elvas s/n, E-06071 Badajoz (Spain)

    2006-10-15

    In this study the energy potential generated by the biomass remnants of vine shoot produced in Extremadura (Spain) by a gasification process is evaluated. The raw material was characterised by elemental and proximate analysis, its Higher Heating Value (HHV) being evaluated as well. In order to determine the optimal gasification temperature for the production of gases, the vine shoots were treated at different temperatures, i.e., 650, 700, 750 and 800 {sup o}C in air atmosphere. The optimal temperature (800 {sup o}C) was selected and the vine shoot remnants were gasified in air stream (200 mL min{sup -1}) and for different times (8 and 50 min). The yield of the so-obtained phases was calculated and the study was focused on solid and gaseous phases. The solid phase was characterised by elemental and proximate analysis as well as by HHV. In order to determine their properties as precursors of activated carbons, the adsorption isotherms of N{sub 2} at 77 K were measured. Finally, the electric power that could be obtained by a combustion process in a vapor boiler was calculated. (author)

  14. Hard-tip, soft-spring lithography.

    Science.gov (United States)

    Shim, Wooyoung; Braunschweig, Adam B; Liao, Xing; Chai, Jinan; Lim, Jong Kuk; Zheng, Gengfeng; Mirkin, Chad A

    2011-01-27

    Nanofabrication strategies are becoming increasingly expensive and equipment-intensive, and consequently less accessible to researchers. As an alternative, scanning probe lithography has become a popular means of preparing nanoscale structures, in part owing to its relatively low cost and high resolution, and a registration accuracy that exceeds most existing technologies. However, increasing the throughput of cantilever-based scanning probe systems while maintaining their resolution and registration advantages has from the outset been a significant challenge. Even with impressive recent advances in cantilever array design, such arrays tend to be highly specialized for a given application, expensive, and often difficult to implement. It is therefore difficult to imagine commercially viable production methods based on scanning probe systems that rely on conventional cantilevers. Here we describe a low-cost and scalable cantilever-free tip-based nanopatterning method that uses an array of hard silicon tips mounted onto an elastomeric backing. This method-which we term hard-tip, soft-spring lithography-overcomes the throughput problems of cantilever-based scanning probe systems and the resolution limits imposed by the use of elastomeric stamps and tips: it is capable of delivering materials or energy to a surface to create arbitrary patterns of features with sub-50-nm resolution over centimetre-scale areas. We argue that hard-tip, soft-spring lithography is a versatile nanolithography strategy that should be widely adopted by academic and industrial researchers for rapid prototyping applications.

  15. Numerical analysis of turbine blade tip treatments

    Science.gov (United States)

    Gopalaswamy, Nath S.; Whitaker, Kevin W.

    1992-01-01

    Three-dimensional solutions of the Navier-Stokes equations for a turbine blade with a turning angle of 180 degrees have been computed, including blade tip treatments involving cavities. The geometry approximates a preliminary design for the GGOT (Generic Gas Oxidizer Turbine). The data presented here will be compared with experimental data to be obtained from a linear cascade using original GGOT blades. Results have been computed for a blade with 1 percent clearance, based on chord, and three different cavity sizes. All tests were conducted at a Reynolds number of 4 x 10 exp 7. The grid contains 39,440 points with 10 spanwise planes in the tip clearance region of 5.008E-04 m. Streamline plots and velocity vectors together with velocity divergence plots reveal the general flow behavior in the clearance region. Blade tip temperature calculations suggest placement of a cavity close to the upstream side of the blade tip for reduction of overall blade tip temperature. The solutions do not account for the relative motion between the endwall and the turbine blade. The solutions obtained are generally consistent with previous work done in this area,

  16. Centrifugal compressor tip clearance and impeller flow

    Energy Technology Data Exchange (ETDEWEB)

    Jaatinen-Varri, Ahti; Tiainen, Jonna; Turunen-Saaresti, Teemu; Gronman, Aki; Ameli, Alireza; Backman, Jari [Laboratory of Fluid Dynamics, LUT School of Energy Systems, Lappeenranta University of Technology, Lappeenranta (Finland); Engeda, Abraham [Turbomachinery Laboratory, Dept. of Mechanical Engineering, Michigan State University, East Lansing (United States)

    2016-11-15

    Compressors consume a considerable portion of the electricity used in the industrial sector. Hence, improvements in compressor efficiency lead to energy savings and reduce environmental impacts. The efficiency of an unshrouded centrifugal compressor suffers from leakage flow over the blade tips. The effect of tip leakage flow on the passage flow differs between the full and splitter blade passages. In this study, the differences in the flow fields between the full and splitter blade passages were studied numerically in detail. An industrial high-speed compressor with a design pressure ratio of 1.78 was modelled. Numerical studies were conducted with six different tip clearances and three different diffuser widths. The results show that increasing tip clearance considerably increases the reversed flow into the impeller with an unpinched diffuser. The reversed flow then partly mixes into the flow in the same blade passage it entered the impeller and the rest migrates over the blade, mixing with the tip clearance flow. Furthermore, as the reversed and clearance flow mix into the wake, the wake is weakened. As pinch reduces both the reversed flow and clearance flow, the passage wakes are stronger with pinches. However, the pinch is beneficial as the losses at the impeller outlet decrease.

  17. Centrifugal compressor tip clearance and impeller flow

    International Nuclear Information System (INIS)

    Jaatinen-Varri, Ahti; Tiainen, Jonna; Turunen-Saaresti, Teemu; Gronman, Aki; Ameli, Alireza; Backman, Jari; Engeda, Abraham

    2016-01-01

    Compressors consume a considerable portion of the electricity used in the industrial sector. Hence, improvements in compressor efficiency lead to energy savings and reduce environmental impacts. The efficiency of an unshrouded centrifugal compressor suffers from leakage flow over the blade tips. The effect of tip leakage flow on the passage flow differs between the full and splitter blade passages. In this study, the differences in the flow fields between the full and splitter blade passages were studied numerically in detail. An industrial high-speed compressor with a design pressure ratio of 1.78 was modelled. Numerical studies were conducted with six different tip clearances and three different diffuser widths. The results show that increasing tip clearance considerably increases the reversed flow into the impeller with an unpinched diffuser. The reversed flow then partly mixes into the flow in the same blade passage it entered the impeller and the rest migrates over the blade, mixing with the tip clearance flow. Furthermore, as the reversed and clearance flow mix into the wake, the wake is weakened. As pinch reduces both the reversed flow and clearance flow, the passage wakes are stronger with pinches. However, the pinch is beneficial as the losses at the impeller outlet decrease

  18. Ecophysiological function of leaf 'windows' in Lithops species - 'Living Stones' that grow underground.

    Science.gov (United States)

    Martin, C E; Brandmeyer, E A; Ross, R D

    2013-01-01

    Leaf temperatures were lower when light entry at the leaf tip window was prevented through covering the window with reflective tape, relative to leaf temperatures of plants with leaf tip windows covered with transparent tape. This was true when leaf temperatures were measured with an infrared thermometer, but not with a fine-wire thermocouple. Leaf tip windows of Lithops growing in high-rainfall regions of southern Africa were larger than the windows of plants (numerous individuals of 17 species) growing in areas with less rainfall and, thus, more annual insolation. The results of this study indicate that leaf tip windows of desert plants with an underground growth habit can allow entry of supra-optimal levels of radiant energy, thus most likely inhibiting photosynthetic activity. Consequently, the size of the leaf tip windows correlates inversely with habitat solar irradiance, minimising the probability of photoinhibition, while maximising the absorption of irradiance in cloudy, high-rainfall regions. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Correlation of arbuscular mycorrhizal colonization with plant growth, nodulation, and shoot npk in legumes

    International Nuclear Information System (INIS)

    Javaid, A.; Anjum, T.; Shah, M.H.M.

    2007-01-01

    Correlation of arbuscular mycorrhizal colonization with different root and shoot growth, nodulation and shoot NPK parameters was studied in three legumes viz. Trifolium alexandrianum, Medicago polymorpha and Melilotus parviflora. The three test legume species showed different patterns of root and shoot growth, nodulation, mycorrhizal colonization and shoot N, P and K content. Different mycorrhizal structures viz. mycelium, arbuscules and vesicles showed different patters of correlation with different studied parameters. Mycelial infection showed an insignificantly positive correlation with root and shoot dry biomass and total root length. Maximum root length was however, negatively associated with mycelial infection. Both arbuscular and vesicular infections were negatively correlated with shoot dry biomass and different parameters of root growth. The association between arbuscular infection and maximum root length was significant. All the three mycorrhizal structures showed a positive correlation with number and biomass of nodules. The association between arbuscular infection and nodule number was significant. Mycelial infection was positively correlated with percentage and total shoot N and P. Similarly percentage N was also positively correlated with arbuscular and vesicular infections. By contrast, total shoot N showed a negative association with arbuscular as well as vesicular infections. Similarly both percentage and total shoot P were negatively correlated with arbuscular and vesicular infections. All the associations between mycorrhizal parameters and shoot K were negative except between vesicular infection and shoot %K. (author)

  20. Mass Shootings: The Role of the Media in Promoting Generalized Imitation.

    Science.gov (United States)

    Meindl, James N; Ivy, Jonathan W

    2017-03-01

    Mass shootings are a particular problem in the United States, with one mass shooting occurring approximately every 12.5 days. Recently a "contagion" effect has been suggested wherein the occurrence of one mass shooting increases the likelihood of another mass shooting occurring in the near future. Although contagion is a convenient metaphor used to describe the temporal spread of a behavior, it does not explain how the behavior spreads. Generalized imitation is proposed as a better model to explain how one person's behavior can influence another person to engage in similar behavior. Here we provide an overview of generalized imitation and discuss how the way in which the media report a mass shooting can increase the likelihood of another shooting event. Also, we propose media reporting guidelines to minimize imitation and further decrease the likelihood of a mass shooting.

  1. Nanobits - exchangable and customisable scanning probe tips

    DEFF Research Database (Denmark)

    Yildiz, Izzet

    dimensions: tips suitable for imaging high-aspect ratio structures and sidewall profiles were designed. Tip diameters in the order of 30 nm were reproducibly obtained with the FIB milling and the smallest tip diameter achieved was ... process by providing direct picking up of the NanoBits by the AFM probe was investigated. Two different bending mechanisms were studied for out-of-plane bending studies: FIB irradiation- and the residual stress-driven bending in bimorph structures. With FIB irradiation studies, NanoBits were demonstrated...... of the structure which may be starting at 170°C. The fabricated NanoBits were assembled and their performance as AFM probes were tested at OFFIS. The NanoBits were successfully picked up by a microgripper, collected in a cartridge and mounted to an AFM probe. Performances of the assembled high-aspect-ratio Nano...

  2. Tipping elements in the Arctic marine ecosystem.

    Science.gov (United States)

    Duarte, Carlos M; Agustí, Susana; Wassmann, Paul; Arrieta, Jesús M; Alcaraz, Miquel; Coello, Alexandra; Marbà, Núria; Hendriks, Iris E; Holding, Johnna; García-Zarandona, Iñigo; Kritzberg, Emma; Vaqué, Dolors

    2012-02-01

    The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem.

  3. Some observations of tip-vortex cavitation

    Science.gov (United States)

    Arndt, R. E. A.; Arakeri, V. H.; Higuchi, H.

    1991-08-01

    Cavitation has been observed in the trailing vortex system of an elliptic platform hydrofoil. A complex dependence on Reynolds number and gas content is noted at inception. Some of the observations can be related to tension effects associated with the lack of sufficiently large-sized nuclei. Inception measurements are compared with estimates of pressure in the vortex obtained from LDV measurements of velocity within the vortex. It is concluded that a complete correlation is not possible without knowledge of the fluctuating levels of pressure in tip-vortex flows. When cavitation is fully developed, the observed tip-vortex trajectory flows. When cavitation is fully developed, the observed tip-vortex trajectory shows a surprising lack of dependence on any of the physical parameters varied, such as angle of attack, Reynolds number, cavitation number, and dissolved gas content.

  4. Tip vortices in the actuator line model

    Science.gov (United States)

    Martinez, Luis; Meneveau, Charles

    2017-11-01

    The actuator line model (ALM) is a widely used tool to represent the wind turbine blades in computational fluid dynamics without the need to resolve the full geometry of the blades. The ALM can be optimized to represent the `correct' aerodynamics of the blades by choosing an appropriate smearing length scale ɛ. This appropriate length scale creates a tip vortex which induces a downwash near the tip of the blade. A theoretical frame-work is used to establish a solution to the induced velocity created by a tip vortex as a function of the smearing length scale ɛ. A correction is presented which allows the use of a non-optimal smearing length scale but still provides the downwash which would be induced using the optimal length scale. Thanks to the National Science Foundation (NSF) who provided financial support for this research via Grants IGERT 0801471, IIA-1243482 (the WINDINSPIRE project) and ECCS-1230788.

  5. Root-zone temperatures affect phenology of bud break, flower cluster development, shoot extension growth and gas exchange of 'Braeburn' (Malus domestica) apple trees.

    Science.gov (United States)

    Greer, Dennis H; Wünsche, Jens N; Norling, Cara L; Wiggins, Harry N

    2006-01-01

    We investigated the effects of root-zone temperature on bud break, flowering, shoot growth and gas exchange of potted mature apple (Malus domestica (Borkh.)) trees with undisturbed roots. Soil respiration was also determined. Potted 'Braeburn' apple trees on M.9 rootstock were grown for 70 days in a constant day/night temperature regime (25/18 degrees C) and one of three constant root-zone temperatures (7, 15 and 25 degrees C). Both the proportion and timing of bud break were significantly enhanced as root-zone temperature increased. Rate of floral cluster opening was also markedly increased with increasing root-zone temperature. Shoot length increased but shoot girth growth declined as root-zone temperatures increased. Soil respiration and leaf photosynthesis generally increased as root-zone temperatures increased. Results indicate that apple trees growing in regions where root zone temperatures are or = 15 degrees C. The effect of root-zone temperature on shoot performance may be mediated through the mobilization of root reserves, although the role of phytohormones cannot be discounted. Variation in leaf photosynthesis across the temperature treatments was inadequately explained by stomatal conductance. Given that root growth increases with increasing temperature, changes in sink activity induced by the root-zone temperature treatments provide a possible explanation for the non-stomatal effect on photosynthesis. Irrespective of underlying mechanisms, root-zone temperatures influence bud break and flowering in apple trees.

  6. Organization of growing random networks

    International Nuclear Information System (INIS)

    Krapivsky, P. L.; Redner, S.

    2001-01-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A k . When A k grows more slowly than linearly with k, the number of nodes with k links, N k (t), decays faster than a power law in k, while for A k growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A k is asymptotically linear, N k (t)∼tk -ν , with ν dependent on details of the attachment probability, but in the range 2 -2 power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network

  7. Spine micromorphology of normal and hyperhydric Mammillaria gracilis Pfeiff. (Cactaceae) shoots.

    Science.gov (United States)

    Peharec, P; Posilović, H; Balen, B; Krsnik-Rasol, M

    2010-07-01

    Artificial conditions of tissue culture affect growth and physiology of crassulacean acid metabolism plants which often results in formation of hyperhydric shoots. In in vitro conditions Mammillaria gracilis Pfeiff. (Cactaceae) growth switches from organized to unorganized way, producing a habituated organogenic callus which simultaneously regenerates morphologically normal as well as altered hyperhydric shoots. In this study, influence of tissue culture conditions on morphology of cactus spines of normal and hyperhydric shoots was investigated. Spines of pot-grown Mammillaria plants and of in vitro regenerated shoots were examined with stereo microscope and scanning electron microscope. The pot-grown plants had 16-17 spines per areole. In vitro grown normal shoots, even though they kept typical shoot morphology, had lower number of spines (11-12) and altered spine morphology. This difference was even more pronounced in spine number (six to seven) and morphology of the hyperhydric shoots. Scanning electron microscopy analysis revealed remarkable differences in micromorphology of spine surface between pot-grown and in vitro grown shoots. Spines of in vitro grown normal shoots showed numerous long trichomes, which were more elongated on spines of the hyperhydric shoots; the corresponding structures on spine surface of pot-grown plants were noticed only as small protrusions. Scanning electron microscopy morphometric studies showed that the spines of pot-grown plants were significantly longer compared to the spines of shoots grown in tissue culture. Moreover, transverse section shape varies from elliptical in pot-grown plants to circular in normal and hyperhydric shoots grown in vitro. Cluster and correspondence analyses performed on the scanning electron microscope obtained results suggest great variability among spines of pot-grown plants. Spines of in vitro grown normal and hyperhydric shoots showed low level of morphological variation among themselves despite the

  8. Tip-Based Nanofabrication for Scalable Manufacturing

    Directory of Open Access Journals (Sweden)

    Huan Hu

    2017-03-01

    Full Text Available Tip-based nanofabrication (TBN is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. In this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

  9. Tip-Based Nanofabrication for Scalable Manufacturing

    International Nuclear Information System (INIS)

    Hu, Huan; Somnath, Suhas

    2017-01-01

    Tip-based nanofabrication (TBN) is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. Here in this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

  10. Twelve tips for "flipping" the classroom.

    Science.gov (United States)

    Moffett, Jennifer

    2015-04-01

    The flipped classroom is a pedagogical model in which the typical lecture and homework elements of a course are reversed. The following tips outline the steps involved in making a successful transition to a flipped classroom approach. The tips are based on the available literature alongside the author's experience of using the approach in a medical education setting. Flipping a classroom has a number of potential benefits, for example increased educator-student interaction, but must be planned and implemented carefully to support effective learning.

  11. Windows 7 Annoyances Tips, Secrets, and Solutions

    CERN Document Server

    Karp, David

    2010-01-01

    Windows 7 may be faster and more stable than Vista, but it's a far cry from problem-free. David A. Karp comes to the rescue with the latest in his popular Windows Annoyances series. This thorough guide gives you the tools you need to fix the troublesome parts of this operating system, plus the solutions, hacks, and timesaving tips to make the most of your PC. Streamline Windows Explorer, improve the Search tool, eliminate the Green Ribbon of Death, and tame User Account Control promptsExplore powerful Registry tips and tools, and use them to customize every aspect of Windows and solve its sho

  12. Study of tip loss corrections using CFD rotor computations

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zhu, Wei Jun; Sørensen, Jens Nørkær

    2014-01-01

    Tip loss correction is known to play an important role for engineering prediction of wind turbine performance. There are two different types of tip loss corrections: tip corrections on momentum theory and tip corrections on airfoil data. In this paper, we study the latter using detailed CFD...... computations for wind turbines with sharp tip. Using the technique of determination of angle of attack and the CFD results for a NordTank 500 kW rotor, airfoil data are extracted and a new tip loss function on airfoil data is derived. To validate, BEM computations with the new tip loss function are carried out...... and compared with CFD results for the NordTank 500 kW turbine and the NREL 5 MW turbine. Comparisons show that BEM with the new tip loss function can predict correctly the loading near the blade tip....

  13. Tip off the HAT- Epigenetic control of learning and memory by Drosophila Tip60.

    Science.gov (United States)

    Xu, Songjun; Elefant, Felice

    2015-01-01

    Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders.

  14. Dielectrophoretic positioning of single nanoparticles on atomic force microscope tips for tip-enhanced Raman spectroscopy.

    Science.gov (United States)

    Leiterer, Christian; Deckert-Gaudig, Tanja; Singh, Prabha; Wirth, Janina; Deckert, Volker; Fritzsche, Wolfgang

    2015-05-01

    Tip-enhanced Raman spectroscopy, a combination of Raman spectroscopy and scanning probe microscopy, is a powerful technique to detect the vibrational fingerprint of molecules at the nanometer scale. A metal nanoparticle at the apex of an atomic force microscope tip leads to a large enhancement of the electromagnetic field when illuminated with an appropriate wavelength, resulting in an increased Raman signal. A controlled positioning of individual nanoparticles at the tip would improve the reproducibility of the probes and is quite demanding due to usually serial and labor-intensive approaches. In contrast to commonly used submicron manipulation techniques, dielectrophoresis allows a parallel and scalable production, and provides a novel approach toward reproducible and at the same time affordable tip-enhanced Raman spectroscopy tips. We demonstrate the successful positioning of an individual plasmonic nanoparticle on a commercial atomic force microscope tip by dielectrophoresis followed by experimental proof of the Raman signal enhancing capabilities of such tips. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The correlation of the radiocaesium concentration of new shoots harvested in 2012 and old leaves, and new shoots harvested in 2011 grown in Kanagawa prefecture

    International Nuclear Information System (INIS)

    Shiraki, Yoshiya; Takeda, Hajime; Okamoto, Tamotsu; Kita, Nobuhiro

    2013-01-01

    We conducted this study to analyze the correlation between 137 Cs concentration of new shoots harvested in the first crop of tea in 2012, and new shoots harvested in the shuto-bancha in 2011 and old leaves harvested at the same time respectively. In the first crop of tea in 2012, the 137 Cs concentration of new shoots was related to that of old leaves, and the correlation of the coefficient was 0.663(p 137 Cs concentration(new shoots/old leaves) was related to the days until harvest of the first crop of tea in 2012, and the correlation coefficient was -0.771(p 137 Cs concentration was derived from the dilution effect due to growth and development of tea plants. Regression analysis was performed to forecast the 137 Cs concentration of the new shoots in the first crop of tea. The 137 Cs concentration of new shoots in the harvested first crop of tea(Y) was related to the 137 Cs concentration of old leaves harvested the previous winter(X). The correlation of the coefficient was 0.783(p 137 Cs concentration of new shoots of the first crop of tea in 2012 decreased about 1/6 to 1/25 compared with that of new shoots of the first crop of tea in 2011. (author)

  16. Numerical investigation of three wind turbine blade tips

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, J.; Soerensen, N.N.

    2002-08-01

    The complex three-dimensional flow around three different tip shapes on a rotating wind turbine blade is investigated and analyzed using Computational Fluid Dynamics. Differences in production, flap wise bending moments and forces are discussed. A method for determining the local inflow angle of attack is presented and further analysis is performed on lift and drag coefficients. It is shown that the original Standard tip results in a more concentrated tip vortex leading to a steeper gradient on both tangential and normal forces when approaching the tip, whereas the two tapered tips show a more flat behavior. This again leads to lower flap wise bending moments and lower production for the Standard tip compared to the two tapered tips. At 12 m/s, though, the Swept tip shows a separation pattern on the surface. This separation causes a decrease in normal force and an increase in tangential force. The Taper tip keeps the higher loading causing the flap wise bending moment to be higher as seen in measurements. To determine the radial variation of lift and drag coefficients the local inflow angle of attack is determined. It is shown that the Standard tip experiences a slightly larger angle of attack at the tip compared to the two tapered tips. The lift coefficients are kept at a more constant level for the two tapered tips due to the decrease in chord, while the drag coefficients actually decrease for the two tapered tips, especially for the Swept tip. For the Swept tip at 12 m/s both lift and drag coefficients changed considerably due to the separation. Differences in aerodynamic damping of the three tips were investigated using HAWCDAMP. The Standard tip seems to be slightly less damped with respect to the edgewise vibrations. (au)

  17. Ten Tips for Better Time Management.

    Science.gov (United States)

    Van Loozen, Luann F.

    1982-01-01

    Presents time management tips, especially for board of education members, including recommendations to realize that managing time is a skill, develop a more accurate sense of how one's time is spent, examine and reestablish goals, learn to say no, organize files and information, and master the telephone. (Author/JM)

  18. The Tipping Points of Technology Development

    Directory of Open Access Journals (Sweden)

    Tauno Kekäle

    2014-07-01

    Full Text Available The tipping point, the decisive point in time in the competition between old and new, is an interesting phenomenon in physics of today. This aspect in technology acceptance is connected to many business decisions such as technology investments, product releases, resource allocation, sales forecasts and, ultimately, affects the profitability and even survival of a company. The tipping point itself is based on many stochastic and dynamic variables, and the process may at least partly be described as path-dependent. This paper analyses the tipping point from three aspects: (1 product performance, (2 features of the market and infrastructure (including related technologies and human network externalities, and (3 actions of the incumbents (including customer lock-in, systems lock-in, and sustaining innovation. The paper is based on the Bass s-curve idea and the technology trajectory concept proposed by Dosi. Three illustrative cases are presented to make the point of the multiple factors affecting technology acceptance and, thus, the tipping point. The paper also suggests outlines for further research in field of computer simulation.

  19. Tip Saves Energy, Money for Pennsylvania Plant

    Science.gov (United States)

    A wastewater treatment plant in Berks County, Pennsylvania is saving nearly $45,000 a year and reducing hundreds of metric tons of greenhouse gases since employing an energy conservation tip offered by the Water Protection Division in EPA’s R3 and PADEP.

  20. The Tipping Point and the Adventure Advantage.

    Science.gov (United States)

    Prouty, Dick

    1998-01-01

    Insights from chaos theory--the interconnectedness of everything, nonlinear cause and effect, leverage and the "tipping point," and the importance of aligning interventions within a system--are applied to social action and illustrated via the role of adventure education in school and community interventions in the Brattleboro (Vermont) Leadership…