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Sample records for shoot meristem identity

  1. 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.

  2. Meristem identity and phyllotaxis in inflorescence development

    Directory of Open Access Journals (Sweden)

    Madelaine Elisabeth Bartlett

    2014-10-01

    Full Text Available Inflorescence morphology is incredibly diverse. This diversity of form has been a fruitful source of inquiry for plant morphologists for more than a century. Work in the grasses (Poaceae, the tomato family (Solanaceae, and Arabidopsis (Brassicaceae has led to a richer understanding of the molecular genetics underlying this diversity. The character of individual meristems, a combination of the number (determinacy and nature (identity of the products a meristem produces, is key in the development of plant form. A framework that describes inflorescence development in terms of shifting meristem identities has emerged and garnered empirical support in a number of model systems. We discuss this framework and highlight one important aspect of meristem identity that is often considered in isolation, phyllotaxis. Phyllotaxis refers to the arrangement of lateral organs around a central axis. The development and evolution of phyllotaxis in the inflorescence remains underexplored, but recent work analyzing early inflorescence development in the grasses identified an evolutionary shift in primary branch phyllotaxis in the Pooideae. We discuss the evidence for an intimate connection between meristem identity and phyllotaxis in both the inflorescence and vegetative shoot, and touch on what is known about the establishment of phyllotactic patterns in the meristem. Localized auxin maxima are instrumental in determining the position of lateral primordia. Upstream factors that regulate the position of these maxima remain unclear, and how phyllotactic patterns change over the course of a plant’s lifetime and evolutionary time, is largely unknown. A more complete understanding of the molecular underpinnings of phyllotaxis and architectural diversity in inflorescences will require capitalizing on the extensive resources available in existing genetic systems, and developing new model systems that more fully represent the diversity of plant morphology.

  3. Meristem identity and phyllotaxis in inflorescence development.

    Science.gov (United States)

    Bartlett, Madelaine E; Thompson, Beth

    2014-01-01

    Inflorescence morphology is incredibly diverse. This diversity of form has been a fruitful source of inquiry for plant morphologists for more than a century. Work in the grasses (Poaceae), the tomato family (Solanaceae), and Arabidopsis thaliana (Brassicaceae) has led to a richer understanding of the molecular genetics underlying this diversity. The character of individual meristems, a combination of the number (determinacy) and nature (identity) of the products a meristem produces, is key in the development of plant form. A framework that describes inflorescence development in terms of shifting meristem identities has emerged and garnered empirical support in a number of model systems. We discuss this framework and highlight one important aspect of meristem identity that is often considered in isolation, phyllotaxis. Phyllotaxis refers to the arrangement of lateral organs around a central axis. The development and evolution of phyllotaxis in the inflorescence remains underexplored, but recent work analyzing early inflorescence development in the grasses identified an evolutionary shift in primary branch phyllotaxis in the Pooideae. We discuss the evidence for an intimate connection between meristem identity and phyllotaxis in both the inflorescence and vegetative shoot, and touch on what is known about the establishment of phyllotactic patterns in the meristem. Localized auxin maxima are instrumental in determining the position of lateral primordia. Upstream factors that regulate the position of these maxima remain unclear, and how phyllotactic patterns change over the course of a plant's lifetime and evolutionary time, is largely unknown. A more complete understanding of the molecular underpinnings of phyllotaxis and architectural diversity in inflorescences will require capitalizing on the extensive resources available in existing genetic systems, and developing new model systems that more fully represent the diversity of plant morphology.

  4. A seed treatment to prevent shoot apical meristem arrest in Brassica oleracea

    NARCIS (Netherlands)

    Jonge, de J.; Goffman, Fernando D.; Kodde, J.; Angenent, G.C.; Groot, S.P.C.

    2018-01-01

    Brassica oleracea plants can suffer from shoot apical meristem arrest, when sown at cold temperatures, giving rise to so-called blind seedlings that stop development and the formation of new leaves. We developed a seed treatment that strongly reduces the occurrence of this meristem arrest in

  5. 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.

  6. 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.

  7. 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...

  8. Live Imaging of Shoot Meristems on an Inverted Confocal Microscope Using an Objective Lens Inverter Attachment

    Science.gov (United States)

    Nimchuk, Zachary L.; Perdue, Tony D.

    2017-01-01

    Live imaging of above ground meristems can lead to new insights in plant development not possible from static imaging of fixed tissue. The use of an upright confocal microscope offers several technical and biological advantages for live imaging floral or shoot meristems. However, many departments and core facilities possess only inverted confocal microscopes and lack the funding for an additional upright confocal microscope. Here we show that imaging of living apical meristems can be performed on existing inverted confocal microscopes with the use of an affordable and detachable InverterScope accessory. PMID:28579995

  9. Live Imaging of Shoot Meristems on an Inverted Confocal Microscope Using an Objective Lens Inverter Attachment.

    Science.gov (United States)

    Nimchuk, Zachary L; Perdue, Tony D

    2017-01-01

    Live imaging of above ground meristems can lead to new insights in plant development not possible from static imaging of fixed tissue. The use of an upright confocal microscope offers several technical and biological advantages for live imaging floral or shoot meristems. However, many departments and core facilities possess only inverted confocal microscopes and lack the funding for an additional upright confocal microscope. Here we show that imaging of living apical meristems can be performed on existing inverted confocal microscopes with the use of an affordable and detachable InverterScope accessory.

  10. Comparative evaluation of total RNA extraction methods in Theobroma cacao using shoot apical meristems.

    Science.gov (United States)

    Silva, D V; Branco, S M J; Holanda, I S A; Royaert, S; Motamayor, J C; Marelli, J P; Corrêa, R X

    2016-03-04

    Theobroma cacao is a species of great economic importance with its beans used for chocolate production. The tree has been a target of various molecular studies. It contains many polyphenols, which complicate the extraction of nucleic acids with the extraction protocols requiring a large amount of plant material. These issues, therefore, necessitate the optimization of the protocols. The aim of the present study was to evaluate different methods for extraction of total RNA from shoot apical meristems of T. cacao 'CCN 51' and to assess the influence of storage conditions for the meristems on the extraction. The study also aimed to identify the most efficient protocol for RNA extraction using a small amount of plant material. Four different protocols were evaluated for RNA extraction using one shoot apical meristem per sample. Among these protocols, one that was more efficient was then tested to extract RNA using four different numbers of shoot apical meristems, subjected to three different storage conditions. The best protocol was tested for cDNA amplification using reverse transcription-polymerase chain reaction; the cDNA quality was determined to be satisfactory for molecular analyses. The study revealed that with the best RNA extraction protocol, one shoot apical meristem was sufficient for extraction of high-quality total RNA. The results obtained might enable advances in genetic analyses and molecular studies using reduced amount of plant material.

  11. 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

  12. Nitrate modulates stem cell dynamics in Arabidopsis shoot meristems through cytokinins

    OpenAIRE

    Jonsson, Sten Henrik; Meyerowitz,; Landrein, Benoit Pierre; Formosa-Jordan,; Malivert,; Schuster, C; Melnyk, CW; Yang, W; Turnbull,; Locke, James Charles

    2018-01-01

    The shoot apical meristem (SAM) is responsible for the generation of all of the aerial parts of plants. Given its critical role, dynamical changes in SAM activity should play a central role in the adaptation of plant architecture to the environment. Using quantitative microscopy, grafting experiments and genetic perturbations, we connect the plant environment to the SAM, by describing the molecular mechanism by which cytokinins signal the level of nutrient availability to the SAM. We show tha...

  13. 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.

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

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    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.

  15. Cell walls as a stage for intercellular communication regulating shoot meristem development

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    Toshiaki eTameshige

    2015-05-01

    Full Text Available Aboveground organs of plants are ultimately derived/generated from the shoot apical meristem (SAM, which is the proliferative tissue located at the apex of the stem. The SAM contains a population of stem cells that provide new cells for organ/tissue formation. The SAM is composed of distinct cell layers and zones with different properties. Primordia of lateral organs develop at the periphery of the SAM. The shoot apex is a dynamic and complex tissue, and as such intercellular communications among cells, layers and zones play significant roles in the coordination of cell proliferation, growth and differentiation to achieve elaborate morphogenesis. Recent findings have highlighted the importance of a number of singling molecules acting in the cell wall space for the intercellular communication, including classic phytohormones and secretory peptides. Moreover, accumulating evidences reveal that cell wall properties and their modifying enzymes modulate hormone actions. In this review, we overview how behaviors of singling molecules and changes of cell wall properties are integrated for the shoot meristem regulation.

  16. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis

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    Hongyan eGuo

    2015-05-01

    Full Text Available Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION gene, as an auxin response gene, and the functional characterization of OsCLE48 in Arabidopsis and rice. OsCLE48 encodes a CLE peptide hormone that is similar to Arabidopsis CLEs. RT-PCR analysis showed that OsCLE48 was induced by exogenously application of IAA (indole-3-acetic acid, a naturally occurred auxin. Expression of integrated OsCLE48p:GUS reporter gene in transgenic Arabidopsis plants was also induced by exogenously IAA treatment. These results indicate that OsCLE48 is an auxin responsive gene. Histochemical staining showed that GUS activity was detected in all the tissue and organs of the OsCLE48p:GUS transgenic Arabidopsis plants. Expression of OsCLE48 under the control of the 35S promoter in Arabidopsis inhibited shoot apical meristem development. Expression of OsCLE48 under the control of the CLV3 native regulatory elements almost completely complemented clv3-2 mutant phenotypes, suggesting that OsCLE48 is functionally similar to CLV3. On the other hand, expression of OsCLE48 under the control of the 35S promoter in Arabidopsis has little, if any effects on root apical meristem development, and transgenic rice plants overexpressing OsCLE48 are morphologically indistinguishable from wild type plants, suggesting that the functions of some CLE peptides may not be fully conserved in Arabidopsis and rice.

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

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    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.

  18. UFO in the Arabidopsis inflorescence apex is required for floral-meristem identity and bract suppression.

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    Hepworth, Shelley R; Klenz, Jennifer E; Haughn, George W

    2006-03-01

    The UNUSUAL FLORAL ORGANS (UFO) gene of Arabidopsis encodes an F-box protein required for the determination of floral-organ and floral-meristem identity. Mutation of UFO leads to dramatic changes in floral-organ type which are well-characterized whereas inflorescence defects are more subtle and less understood. These defects include an increase in the number of secondary inflorescences, nodes that alternate between forming flowers and secondary inflorescences, and nodes in which a single flower is subtended by a bract. Here, we show how inflorescence defects correlate with the abnormal development of floral primordia and establish a temporal requirement for UFO in this process. At the inflorescence apex of ufo mutants, newly formed primordia are initially bract-like. Expression of the floral-meristem identity genes LFY and AP1 are confined to a relatively small adaxial region of these primordia with expression of the bract-identity marker FIL observed in cells that comprise the balance of the primordia. Proliferation of cells in the adaxial region of these early primordia is delayed by several nodes such that primordia appear "chimeric" at several nodes, having visible floral and bract components. However, by late stage 2 of floral development, growth of the bract generally ceases and is overtaken by development of the floral primordium. This abnormal pattern of floral meristem development is not rescued by expression of UFO from the AP1 promoter, indicating that UFO is required prior to AP1 activation for normal development of floral primordia. We propose that UFO and LFY are jointly required in the inflorescence meristem to both promote floral meristem development and inhibit, in a non-cell autonomous manner, growth of the bract.

  19. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots.

    Science.gov (United States)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises the questions of how auxin and cytokinin govern fern root system architecture and whether this can tell us something about the origin of that root. Using Azolla filiculoides, we characterized the influence of IAA and zeatin on adventitious fern root meristems and vasculature by Nomarski microscopy. Simultaneously, RNAseq analyses, yielding 36,091 contigs, were used to uncover how the phytohormones affect root tip gene expression. We show that auxin restricts Azolla root meristem development, while cytokinin promotes it; it is the opposite effect of what is observed in Arabidopsis. Global gene expression profiling uncovered 145 genes significantly regulated by cytokinin or auxin, including cell wall modulators, cell division regulators and lateral root formation coordinators. Our data illuminate both evolution and development of fern roots. Promotion of meristem size through cytokinin supports the idea that root meristems of euphyllophytes evolved from shoot meristems. The foundation of these roots was laid in a postembryonically branching shoot system. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. 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

  1. Dynamic expression reveals a two-step patterning of WUS and CLV3 during axillary shoot meristem formation in Arabidopsis.

    Science.gov (United States)

    Xin, Wei; Wang, Zhicai; Liang, Yan; Wang, Yonghong; Hu, Yuxin

    2017-07-01

    Seed plants have a remarkable capability to produce axillary meristems (AM) in the leaf axils, however, the dynamic establishment of a stem cell niche in AM is largely uncharacterized. We comprehensively examined the dynamic patterning of WUSCHEL (WUS) and CLAVATA3 (CLV3), the two key marker genes defining the shoot stem cell niches, during AM formation in Arabidopsis, and we found that a two-step patterning of WUS and CLV3 occurred during AM stem cell niche establishment. Our further work on the wus and clv3 mutants implicates that such two-step patterning is likely critical for the maintenance of AM progenitor cells and the specification of AM stem cell niche. These data provide a cytological frame for how a stem cell niche is established during AM formation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. AGO6 functions in RNA-mediated transcriptional gene silencing in shoot and root meristems in Arabidopsis thaliana.

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    Changho Eun

    Full Text Available RNA-directed DNA methylation (RdDM is a small interfering RNA (siRNA-mediated epigenetic modification that contributes to transposon silencing in plants. RdDM requires a complex transcriptional machinery that includes specialized RNA polymerases, named Pol IV and Pol V, as well as chromatin remodelling proteins, transcription factors, RNA binding proteins, and other plant-specific proteins whose functions are not yet clarified. In Arabidopsis thaliana, DICER-LIKE3 and members of the ARGONAUTE4 group of ARGONAUTE (AGO proteins are involved, respectively, in generating and using 24-nt siRNAs that trigger methylation and transcriptional gene silencing of homologous promoter sequences. AGO4 is the main AGO protein implicated in the RdDM pathway. Here we report the identification of the related AGO6 in a forward genetic screen for mutants defective in RdDM and transcriptional gene silencing in shoot and root apical meristems in Arabidopsis thaliana. The identification of AGO6, and not AGO4, in our screen is consistent with the primary expression of AGO6 in shoot and root growing points.

  3. Cell fate in the Arabidopsis root meristem determined by directional signalling

    NARCIS (Netherlands)

    Berg, C. van den; Willemsen, V.; Hage, W.; Weisbeek, P.; Scheres, B.J.G.

    1995-01-01

    Postembryonic development in plants is achieved by apical meristems. Surgical studies and clonal analysis have revealed indirectly that cells in shoot meristems have no predictable destiny and that position is likely to play a role in the acquisition of cell identity . In contrast to animal

  4. Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence1

    Science.gov (United States)

    Broholm, Suvi K.; Tähtiharju, Sari

    2016-01-01

    The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems. PMID:27382139

  5. Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence.

    Science.gov (United States)

    Zhao, Yafei; Zhang, Teng; Broholm, Suvi K; Tähtiharju, Sari; Mouhu, Katriina; Albert, Victor A; Teeri, Teemu H; Elomaa, Paula

    2016-09-01

    The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems. © 2016 American Society of Plant Biologists. All rights reserved.

  6. The CUP-SHAPED COTYLEDON3 gene is required for boundary and shoot meristem formation in Arabidopsis

    DEFF Research Database (Denmark)

    Vroemen, Casper W; Mordhorst, Andreas P; Albrecht, Cathy

    2003-01-01

    From an enhancer trap screen for genes expressed in Arabidopsis embryos, we identified a gene expressed from the octant stage onward in the boundary between the two presumptive cotyledons and in a variety of postembryonic organ and meristem boundaries. This gene, CUP-SHAPED COTYLEDON3 (CUC3...

  7. Cell fate in the Arabidopsis root meristem determined by directional signalling.

    Science.gov (United States)

    van den Berg, C; Willemsen, V; Hage, W; Weisbeek, P; Scheres, B

    1995-11-02

    Postembryonic development in plants is achieved by apical meristems. Surgical studies and clonal analysis have revealed indirectly that cells in shoot meristems have no predictable destiny and that position is likely to play a role in the acquisition of cell identity. In contrast to animal systems, there has been no direct evidence for inductive signalling in plants until now. Here we present evidence for such signalling using laser ablation of cells in the root meristem of Arabidopsis thaliana. Although these cells show rigid clonal relationships, we now demonstrate that it is positional control that is most important in the determination of cell fate. Positional signals can be perpetuated from more mature to initial cells to guide the pattern of meristem cell differentiation. This offers an alternative to the general opinion that meristems are the source of patterning information.

  8. cDNA-AFLP analysis of gene expression differences between the flower bud and sprout-shoot apical meristem of Angelica sinensis (Oliv. Diels

    Directory of Open Access Journals (Sweden)

    Yu Guang

    2011-01-01

    Full Text Available Angelica sinensis (Oliv. Diels (Umbelliferae is a well-known medicinal plant mainly distributed in Gansu Province of China. Its local and global demand is significant because of its food and medicinal applications. However, the early bolting rate of Angelica sinensis (Oliv. Diels reaches 20%-60%, which seriously affects its food and medicinal qualities. Thus, differences in gene expression between the flower bud and sprout-shoot apical meristem underwent analysis, by means of cDNA-amplified restriction fragment length polymorphism, to better understand the flowering mechanism. 64 primer sets, each of which amplified to 60 transcript-derived fragments (TDFs, were used. Among these TDFs, 26 were expressed specifically in the flower bud. After cloning and sequencing, 32 distinct sequences were obtained from these 26 TDFs, and 25 were found with homologous sequences in databases. Confirmation of differential expression of 13 sequences was obtained by semi-quantitative RT-PCR, their showing higher expression levels in flower buds. These homologous sequences encode transposable elements, pentatricopeptide repeat-containing proteins, DNA-binding transcription factors, zinc finger (B-box type family proteins, NADP-dependent sorbitol 6-phosphate dehydrogenase (S6PDH, amongst others.

  9. Biolistic-mediated transient gene expression in shoot apical meristems of the prickly-pear (Opuntia ficus-indica

    Directory of Open Access Journals (Sweden)

    Romulo Marino Llamoca-Zárate

    1999-01-01

    Full Text Available We have demonstrated the transient expression of the GUS gene in cells of the meristematic apical dome of Opuntia ficus-indica. DNA delivery into the cells was achieved using a biolistic PDS-1000He instrument from Bio-Rad Laboratories. The transforming DNA was coated in tungsten particles with diameter of 1.3 m m and the distance between the flying disk and the target tissue was 7.5cm and the shooting pressure was adjusted to 1200 psi. This is the first demonstration that the biolistic transformation system can be used to express a transgene in a member of the Cactaceae.Nós demonstramos a expressão transiente do gene GUS nas células do meristema apical de Opuntia ficus-indica. A introdução do DNA nas células foi realizada através de um sistema de biolística PDS-1000He da Bio-Rad Laboratories. Para transformação, partículas de tungstenio com diâmetro de 1,3 µm foram cobertas com DNA e a distância entre o disco das partículas e o tecido alvo foi de 7,5cm, a pressão de tiro foi 1200 psi. Esta é a primeira demonstração que o sistema de biolística de transformação pode ser usado para a expressão de transgenes nas cactáceas.

  10. Cytokinin-Deficient Transgenic Arabidopsis Plants Show Multiple Developmental Alterations Indicating Opposite Functions of Cytokinins in the Regulation of Shoot and Root Meristem Activity

    Czech Academy of Sciences Publication Activity Database

    Werner, T.; Motyka, Václav; Laucou, V.; Smets, R.; Onckelen, H. V.; Schmülling, T.

    2003-01-01

    Roč. 15, č. 11 (2003), s. 2532-2550 ISSN 1040-4651 R&D Projects: GA AV ČR IAA6038002 Institutional research plan: CEZ:AV0Z5038910 Keywords : Transgenic Arabidopsis Plants * Cytokinins * Root Meristem Activity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.679, year: 2003

  11. The KNOXI Transcription Factor SHOOT MERISTEMLESS Regulates Floral Fate in Arabidopsis.

    Science.gov (United States)

    Roth, Ohad; Alvarez, John; Levy, Matan; Bowman, John L; Ori, Naomi; Shani, Eilon

    2018-05-09

    Plants have evolved a unique and conserved developmental program that enables the conversion of leaves into floral organs. Elegant genetic and molecular work has identified key regulators of flower meristem identity. However, further understanding of flower meristem specification has been hampered by redundancy and by pleiotropic effects. The KNOXI transcription factor SHOOT MERISTEMLESS (STM) is a well-characterized regulator of shoot apical meristem maintenance. Arabidopsis thaliana stm loss-of-function mutants arrest shortly after germination, and therefore the knowledge on later roles of STM in later processes, including flower development, is limited. Here, we uncover a role for STM in the specification of flower meristem identity. Silencing STM in the APETALA1 (AP1) expression domain in the ap1-4 mutant background resulted in a leafy-flower phenotype, and an intermediate stm-2 allele enhanced the flower meristem identity phenotype of ap1-4. Transcriptional profiling of STM perturbation suggested that STM activity affects multiple floral fate genes, among them the F-Box protein-encoding gene UNUSUAL FLORAL ORGANS (UFO). In agreement with this notion, stm-2 enhanced the ufo-2 floral fate phenotype, and ectopic UFO expression rescued the leafy flowers in genetic backgrounds with compromised AP1 and STM activities. This work suggests a genetic mechanism that underlies the activity of STM in the specification of flower meristem identity. © 2018 American Society of Plant Biologists. All rights reserved.

  12. Establecimiento y multiplicación in vitro de mora de castilla (Rubus glaucus Benth. variedad sin espinas, mediante ápices meristemáticos Stablishment and in vitro multiplication of thornless blackberry (Rubus glaucus Benth. by shoot apical meristems

    Directory of Open Access Journals (Sweden)

    Alina Katil Sigarroa-Rieche

    2011-12-01

    Full Text Available Se evaluó una técnica de micropropagación de plantas de mora (Rubus glaucus de la variedad sin espinas, a partir de ápices meristemáticos. En la fase de establecimiento se evaluó un protocolo de desinfección utilizando por 5 min solución de jabón detergente comercial y agua + alcohol 70% por 2 min + hipoclorito 3% con dos tiempos de exposición diferentes: T1 por 5 min y T2 por 10 min. Después de desinfectar las microestacas se extrajeron los ápices meristemáticos y se establecieron in vitro bajo un diseño completamente al azar para evaluar dos medios de cultivo: M1 y M2. A partir de las plántulas desarrolladas se efectuó la multiplicación en los medios de cultivo M1, M3 y M4. Ambos tratamientos de desinfección resultaron efectivos alcanzando 100% de desinfección de los explantes con cada uno de ellos. La siembra de ápices meristemáticos permitió el establecimiento de cultivos asépticos y un adecuado desarrollo de los explantes después de seis semanas de cultivo, con prendimiento de 83.4% para M1 y 66.6% para M2. El análisis de varianza (Anova y la prueba de rangos múltiples mostraron que la multiplicación fue mejor en el medio M1 con una mayor tasa de crecimiento y desarrollo del explante, al obtener coeficientes de multiplicación de 7.5 brotes/plántula y una altura promedio de 1.95 cm.We evaluated a technique of micropropagation in a thornless variety of blackberry (Rubus glaucus from shoot apical meristems. In the establishment phase, we evaluated a disinfection protocol: soapy solution (commercial detergent and water for 5 minutes + 70% alcohol for 2 minutes + 3% hypochlorite with two different exposure times: T1 for 5 minutes and T2 for 10 minutes. When the microcuttings were disinfected, the meristematic shoots were removed and established in vitro in a completely random design to evaluate two cultivation mediums: M1 and M2. From the seedlings developed, the multiplication was performed, which tested three

  13. The concept of the eudicot shoot apical meristem as it applies to four Spiraea (Rosaceae), one Mentha (Lamiaceae) and one Euonymus (Celastraceae) cultivars based on chimeric analysis.

    Science.gov (United States)

    Korn, Robert W

    2013-05-01

    Eversporting eudicots were sought to see if they behave like gymnosperms. Behaviour of eversporting gymnosperm chimeras indicates a single apical cell is present in SAM and it would be of interest to see if eudicot chimeras have the same behaviour. Four eversporting spireas, the pineapple mint and the Silver King euonymus were inspected for the fate of the yellow (mutant)-green (wild type) chimeras. As with gymnosperms, unstable eudicot chimeras in the four spireas, the pineapple mint and the Silver King euonymus became stable yellow about 80 % or more of the time and 20 % or less became stable green. The statistically significant preponderance of chimeric fates becoming all yellow suggests that a single apical cell resides in the yellow tunica. As with gymnosperms, descendent cells of the yellow replacement corpus cell eventually take over the corpus. Here is the first chimeric set of data to support the hypothesis of a one-celled meristem in eudicots rather than the traditional view of a muticellular meristem.

  14. UFO: an Arabidopsis gene involved in both floral meristem and floral organ development.

    Science.gov (United States)

    Levin, J Z; Meyerowitz, E M

    1995-05-01

    We describe the role of the UNUSUAL FLORAL ORGANS (UFO) gene in Arabidopsis floral development based on a genetic and molecular characterization of the phenotypes of nine ufo alleles. UFO is required for the proper identity of the floral meristem and acts in three different aspects of the process that distinguishes flowers from shoots. UFO is involved in establishing the whorled pattern of floral organs, controlling the determinacy of the floral meristem, and activating the APETALA3 and PISTILLATA genes required for petal and stamen identity. In many respects, UFO acts in a manner similar to LEAFY, but the ufo mutant phenotype also suggests an additional role for UFO in defining boundaries within the floral primordia or controlling cell proliferation during floral organ growth. Finally, genetic interactions that prevent flower formation and lead to the generation of filamentous structures implicate UFO as a member of a new, large, and diverse class of genes in Arabidopsis necessary for flower formation.

  15. Evolution of floral meristem identity genes. Analysis of Lolium temulentum genes related to APETALA1 and LEAFY of Arabidopsis

    DEFF Research Database (Denmark)

    Gocal, G.F.W.; King, R.W.; Blundell, C.A.

    2001-01-01

    Flowering (inflorescence formation) of the grass Lolium temulentum is strictly regulated, occurring rapidly on exposure to a single long day (LD). During floral induction, L. temulentum differs significantly from dicot species such as Arabidopsis in the expression, at the shoot apex, of two APETALA...... are consecutively activated early during flower formation. LtMADS2, when expressed in transgenic Arabidopsis plants under the control of the AP1 promoter, could partially complement the organ number defect of the severe ap1-15 mutant allele, confirming a close relationship between LtMADS2 and AP1....

  16. Potential bud bank responses to apical meristem damage and environmental variables: matching or complementing axillary meristems?

    Science.gov (United States)

    Klimešová, Jitka; Malíková, Lenka; Rosenthal, Jonathan; Šmilauer, Petr

    2014-01-01

    Soil nutrients, dormant axillary meristem availability, and competition can influence plant tolerance to damage. However, the role of potential bud banks (adventitious meristems initiated only after injury) is not known. Examining Central European field populations of 22 species of short-lived monocarpic herbs exposed to various sources of damage, we hypothesized that: (1) with increasing injury severity, the number of axillary branches would decrease, due to axillary meristem limitation, whereas the number of adventitious shoots (typically induced by severe injury) would increase; (2) favorable environmental conditions would allow intact plants to branch more, resulting in stronger axillary meristem limitation than in unfavorable conditions; and (3) consequently, adventitious sprouting would be better enabled in favorable than unfavorable conditions. We found strong support for the first hypothesis, only limited support for the second, and none for the third. Our results imply that whereas soil nutrients and competition marginally influence plant tolerance to damage, potential bud banks enable plants to overcome meristem limitation from severe damage, and therefore better tolerate it. All the significant effects were found in intraspecific comparisons, whereas interspecific differences were not found. Monocarpic plants with potential bud banks therefore represent a distinct strategy occupying a narrow environmental niche. The disturbance regime typical for this niche remains to be examined, as do the costs associated with the banks of adventitious and axillary reserve meristems.

  17. Potential bud bank responses to apical meristem damage and environmental variables: matching or complementing axillary meristems?

    Directory of Open Access Journals (Sweden)

    Jitka Klimešová

    Full Text Available Soil nutrients, dormant axillary meristem availability, and competition can influence plant tolerance to damage. However, the role of potential bud banks (adventitious meristems initiated only after injury is not known. Examining Central European field populations of 22 species of short-lived monocarpic herbs exposed to various sources of damage, we hypothesized that: (1 with increasing injury severity, the number of axillary branches would decrease, due to axillary meristem limitation, whereas the number of adventitious shoots (typically induced by severe injury would increase; (2 favorable environmental conditions would allow intact plants to branch more, resulting in stronger axillary meristem limitation than in unfavorable conditions; and (3 consequently, adventitious sprouting would be better enabled in favorable than unfavorable conditions. We found strong support for the first hypothesis, only limited support for the second, and none for the third. Our results imply that whereas soil nutrients and competition marginally influence plant tolerance to damage, potential bud banks enable plants to overcome meristem limitation from severe damage, and therefore better tolerate it. All the significant effects were found in intraspecific comparisons, whereas interspecific differences were not found. Monocarpic plants with potential bud banks therefore represent a distinct strategy occupying a narrow environmental niche. The disturbance regime typical for this niche remains to be examined, as do the costs associated with the banks of adventitious and axillary reserve meristems.

  18. FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice.

    Directory of Open Access Journals (Sweden)

    Takuya Suzaki

    2009-10-01

    Full Text Available CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM in Arabidopsis thaliana. In rice (Oryza sativa, FLORAL ORGAN NUMBER2 (FON2, closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM. Here we show that the FON2 SPARE1 (FOS1 gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems.

  19. Arabidopsis BLADE-ON-PETIOLE1 and 2 promote floral meristem fate and determinacy in a previously undefined pathway targeting APETALA1 and AGAMOUS-LIKE24.

    Science.gov (United States)

    Xu, Mingli; Hu, Tieqiang; McKim, Sarah M; Murmu, Jhadeswar; Haughn, George W; Hepworth, Shelley R

    2010-09-01

    The transition to flowering is a tightly controlled developmental decision in plants. In Arabidopsis, LEAFY (LFY) and APETALA1 (AP1) are key regulators of this transition and expression of these genes in primordia produced by the inflorescence meristem confers floral fate. Here, we examine the role of architectural regulators BLADE-ON-PETIOLE1 (BOP1) and BOP2 in promotion of floral meristem identity. Loss-of-function bop1 bop2 mutants show subtle defects in inflorescence and floral architecture but in combination with lfy or ap1, synergistic defects in floral meristem fate and determinacy are revealed. The most dramatic changes occur in bop1 bop2 ap1-1 triple mutants where flowers are converted into highly branched inflorescence-like shoots. Our data show that BOP1/2 function distinctly from LFY to upregulate AP1 in floral primordia and that all three activities converge to down-regulate flowering-time regulators including AGAMOUS-LIKE24 in stage 2 floral meristems. Subsequently, BOP1/2 promote A-class floral-organ patterning in parallel with LFY and AP1. Genetic and biochemical evidence support the model that BOP1/2 are recruited to the promoter of AP1 through direct interactions with TGA bZIP transcription factors, including PERIANTHIA. These data reveal an important supporting role for BOP1/2 in remodeling shoot architecture during the floral transition. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

  20. DELLA genes restrict inflorescence meristem function independently of plant height.

    Science.gov (United States)

    Serrano-Mislata, Antonio; Bencivenga, Stefano; Bush, Max; Schiessl, Katharina; Boden, Scott; Sablowski, Robert

    2017-09-01

    DELLA proteins associate with transcription factors to control plant growth in response to gibberellin 1 . Semi-dwarf DELLA mutants with improved harvest index and decreased lodging greatly improved global food security during the 'green revolution' in the 1960-1970s 2 . However, DELLA mutants are pleiotropic and the developmental basis for their effects on plant architecture remains poorly understood. Here, we show that DELLA proteins have genetically separable roles in controlling stem growth and the size of the inflorescence meristem, where flowers initiate. Quantitative three-dimensional image analysis, combined with a genome-wide screen for DELLA-bound loci in the inflorescence tip, revealed that DELLAs limit meristem size in Arabidopsis by directly upregulating the cell-cycle inhibitor KRP2 in the underlying rib meristem, without affecting the canonical WUSCHEL-CLAVATA meristem size regulators 3 . Mutation of KRP2 in a DELLA semi-dwarf background restored meristem size, but not stem growth, and accelerated flower production. In barley, secondary mutations in the DELLA gain-of-function mutant Sln1d 4 also uncoupled meristem and inflorescence size from plant height. Our work reveals an unexpected and conserved role for DELLA genes in controlling shoot meristem function and suggests how dissection of pleiotropic DELLA functions could unlock further yield gains in semi-dwarf mutants.

  1. 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.

  2. Shooting for Lithuania: Migration, national identity and men's basketball in the East of England

    DEFF Research Database (Denmark)

    Evans, Adam Brian; Piggott, David

    2016-01-01

    The accession of the ‘A8 states’ into the European Union initiated considerable migration into Western Europe. The impact upon local communities has seen significant attention, yet little research exists that focuses upon migrant experiences and identity specifically in sport. This study utilized...

  3. "Shoot for the Moon!" Students' Identities as Writers in the Context of the Classroom

    Science.gov (United States)

    Wearmouth, Janice; Berryman, Mere; Whittle, Lisa

    2011-01-01

    A study of students' identities as writers was carried out in the classroom of a New Zealand primary teacher who had been formally identified by a national body of teachers as having excellent practice in supporting literacy acquisition. The researchers, Professor Janice Wearmouth, from the University of Bedfordshire, Mere Berryman, from the…

  4. Racial and Mental Illness Stereotypes and Discrimination: An Identity-Based Analysis of the Virginia Tech and Columbine Shootings

    OpenAIRE

    Chen, Charlene Y.; Purdie-Vaughns, Valerie; Phelan, Jo C.; Yu, Gary; Yang, Lawrence H.

    2014-01-01

    The Virginia Tech and Columbine High shootings are 2 of the deadliest school massacres in the United States. The present study investigates in a nationally representative sample how White Americans’ causal attributions of these shooting moderate their attitudes toward the shooter’s race. White Americans shown a vignette based on the Virginia Tech shooting were more likely to espouse negative beliefs about Korean American men and distance themselves from this group the more they believed that ...

  5. Racial and mental illness stereotypes and discrimination: an identity-based analysis of the Virginia Tech and Columbine shootings.

    Science.gov (United States)

    Chen, Charlene Y; Purdie-Vaughns, Valerie; Phelan, Jo C; Yu, Gary; Yang, Lawrence H

    2015-04-01

    The Virginia Tech and Columbine High shootings are 2 of the deadliest school massacres in the United States. The present study investigates in a nationally representative sample how White Americans' causal attributions of these shooting moderate their attitudes toward the shooter's race. White Americans shown a vignette based on the Virginia Tech shooting were more likely to espouse negative beliefs about Korean American men and distance themselves from this group the more they believed that the shooter's race caused the shooting. Among those who were shown a vignette based on the Columbine High shooting, believing that mental illness caused the shooting was associated with weaker negative beliefs about White American men. White Americans in a third condition who were given the Virginia Tech vignette and prompted to subtype the shooter according to his race were less likely to possess negative beliefs about Korean American men the more they believed that mental illness caused the shooting. There was no evidence for the ultimate attribution error. Theoretical accounts based on the stereotype and in-group-out-group bias literature are presented. The current findings have important implications for media depictions of minority group behavior and intergroup relations. (c) 2015 APA, all rights reserved).

  6. Racial and Mental Illness Stereotypes and Discrimination: An Identity-Based Analysis of the Virginia Tech and Columbine Shootings

    Science.gov (United States)

    Chen, Charlene Y.; Purdie-Vaughns, Valerie; Phelan, Jo C.; Yu, Gary; Yang, Lawrence H.

    2015-01-01

    The Virginia Tech and Columbine High shootings are 2 of the deadliest school massacres in the United States. The present study investigates in a nationally representative sample how White Americans’ causal attributions of these shooting moderate their attitudes toward the shooter’s race. White Americans shown a vignette based on the Virginia Tech shooting were more likely to espouse negative beliefs about Korean American men and distance themselves from this group the more they believed that the shooter’s race caused the shooting. Among those who were shown a vignette based on the Columbine High shooting, believing that mental illness caused the shooting was associated with weaker negative beliefs about White American men. White Americans in a third condition who were given the Virginia Tech vignette and prompted to subtype the shooter according to his race were less likely to possess negative beliefs about Korean American men the more they believed that mental illness caused the shooting. There was no evidence for the ultimate attribution error. Theoretical accounts based on the stereotype and in-group-out-group bias literature are presented. The current findings have important implications for media depictions of minority group behavior and intergroup relations. PMID:25198415

  7. Repression of Lateral Organ Boundary Genes by PENNYWISE and POUND-FOOLISH Is Essential for Meristem Maintenance and Flowering in Arabidopsis

    NARCIS (Netherlands)

    Khan, Madiha; Ragni, Laura; Tabb, Paul; Salasini, Brenda C; Chatfield, Steven; Datla, Raju; Lock, John; Kuai, Xiahezi; Després, Charles; Proveniers, Marcel; Yongguo, Cao; Xiang, Daoquan; Morin, Halima; Rullière, Jean-Pierre; Citerne, Sylvie; Hepworth, Shelley R; Pautot, Véronique

    2015-01-01

    In the model plant Arabidopsis (Arabidopsis thaliana), endogenous and environmental signals acting on the shoot apical meristem cause acquisition of inflorescence meristem fate. This results in changed patterns of aerial development seen as the transition from making leaves to the production of

  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. Irradiation damage and recovery in shoot apices of sweet cherry (Prunus avium L.)

    International Nuclear Information System (INIS)

    Saamin, S.; Thompson, M.M.

    1990-01-01

    Full text: Dormant scions of 'Bing' were exposed to fractionated 6kR gamma rays and then grafted. Irradiated and unirradiated main buds were sampled at 3 day intervals for one month. Buds were fixed in FAA, longitudinally sectioned, and stained with hematoxylin. Both random and localised cell damage was observed in irradiated apices. There was evidence of radiosensitivity gradient in the shoot apex. Recovery from irradiation damage was via flank meristem, central meristem, or leaf primordia and axillary meristems. (author)

  10. Requirement of B2-Type Cyclin-Dependent Kinases for Meristem Integrity in Arabidopsis thaliana

    Czech Academy of Sciences Publication Activity Database

    Andersen, S.U.; Buechel, S.; Zhao, Z.; Ljung, K.; Novák, Ondřej; Busch, W.; Schuster, Ch.; Lohmann, J.U.

    2008-01-01

    Roč. 20, č. 1 (2008), s. 88-100 ISSN 1040-4651 Institutional research plan: CEZ:AV0Z50380511 Keywords : SHOOT APICAL MERISTEM * CELL-CYCLE * PLANT DEVELOPMENT Subject RIV: CE - Biochemistry Impact factor: 9.296, year: 2008

  11. 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.

  12. Meristem maintenance, auxin, jasmonic and abscisic acid pathways as a mechanism for phenotypic plasticity in Antirrhinum majus

    Science.gov (United States)

    Weiss, Julia; Alcantud-Rodriguez, Raquel; Toksöz, Tugba; Egea-Cortines, Marcos

    2016-01-01

    Plants grow under climatic changing conditions that cause modifications in vegetative and reproductive development. The degree of changes in organ development i.e. its phenotypic plasticity seems to be determined by the organ identity and the type of environmental cue. We used intraspecific competition and found that Antirrhinum majus behaves as a decoupled species for lateral organ size and number. Crowding causes decreases in leaf size and increased leaf number whereas floral size is robust and floral number is reduced. Genes involved in shoot apical meristem maintenance like ROA and HIRZ, cell cycle (CYCD3a; CYCD3b, HISTONE H4) or organ polarity (GRAM) were not significantly downregulated under crowding conditions. A transcriptomic analysis of inflorescence meristems showed Gene Ontology enriched pathways upregulated including Jasmonic and Abscisic acid synthesis and or signalling. Genes involved in auxin synthesis such as AmTAR2 and signalling AmANT were not affected by crowding. In contrast, AmJAZ1, AmMYB21, AmOPCL1 and AmABA2 were significantly upregulated. Our work provides a mechanistic working hypothesis where a robust SAM and stable auxin signalling enables a homogeneous floral size while changes in JA and ABA signalling maybe responsible for the decreased leaf size and floral number.

  13. Regeneration of three sweet potato (Ipomea batatas (L.)) accessions via meristem, Nodal and callus induction

    International Nuclear Information System (INIS)

    Addae-Frimpomaah, F.

    2012-11-01

    In vitro regeneration of three sweet potato accessions UE007, UK-BNARI and SA-BNARI using meristem, nodal cuttings or callus induction was studied. Meristematic explants cultured on Murashige and Skoog (1962) basal medium supplemented with low concentration of benzylaminopurine (BAP) or kinetin resulted in callus with or without shoot development which delayed shoot emergence. The degree of callus development increased as the concentration of the cytokinin in the culture medium increased. Although, callus development was comparatively lower on kinetin amended medium than BAP amended medium, Murashige and Skoog medium supplemented with 0.25mg/1BAP had the highest shoot induction (80%). For further differentiation of callus or shoots into distinct stem and leaves, the culture were transferred into fresh MS medium supplemented with 0.25mg/1 BAP, 0.1 mg/1 NAA and 0.1 mg/1 Gibberellic acid (GA 3 . To overcome the delay in shoot initiation using meristem culture, nodal cuttings of sweet potato were used as explants and cultured on MS medium amended with 0.3 - 0.9mg/1 BAP. All explants cultured on 0.3 or 0.6mg/1 BAP developed shoots. Furthermore, liquid MS medium amended with 0.25mg/1 BAP, 0.1mg/I NAA, and 0.1mg/1 GA 3 also enhanced early shoot development from nodal cutting explants compared to solid culture. Post flask acclimatisation of meristem or nodal cutting-derived plantlets showed that meristem derived plantlets were better acclimatised than nodal cutting plants due to vigorous root development leading to higher percentage survival in pots and subsequent tuber production. Callusogenesis was achieved when leaf lobe explants were cultured on CLC/ Ipomoea medium supplemented with 1.0 - 4.0mg/1 2,4-D with 4.0mg/1 2,4-D being the optimal concentration. However, the calli were non-embryogenic and therefore could not produce embryos when transferred to 0.1mg/1 BAP amended medium but rather produced either single or multiple shoots. The highest percentage shoot (83

  14. 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.

  15. Simulation of organ patterning on the floral meristem using a polar auxin transport model.

    Directory of Open Access Journals (Sweden)

    Simon van Mourik

    Full Text Available An intriguing phenomenon in plant development is the timing and positioning of lateral organ initiation, which is a fundamental aspect of plant architecture. Although important progress has been made in elucidating the role of auxin transport in the vegetative shoot to explain the phyllotaxis of leaf formation in a spiral fashion, a model study of the role of auxin transport in whorled organ patterning in the expanding floral meristem is not available yet. We present an initial simulation approach to study the mechanisms that are expected to play an important role. Starting point is a confocal imaging study of Arabidopsis floral meristems at consecutive time points during flower development. These images reveal auxin accumulation patterns at the positions of the organs, which strongly suggests that the role of auxin in the floral meristem is similar to the role it plays in the shoot apical meristem. This is the basis for a simulation study of auxin transport through a growing floral meristem, which may answer the question whether auxin transport can in itself be responsible for the typical whorled floral pattern. We combined a cellular growth model for the meristem with a polar auxin transport model. The model predicts that sepals are initiated by auxin maxima arising early during meristem outgrowth. These form a pre-pattern relative to which a series of smaller auxin maxima are positioned, which partially overlap with the anlagen of petals, stamens, and carpels. We adjusted the model parameters corresponding to properties of floral mutants and found that the model predictions agree with the observed mutant patterns. The predicted timing of the primordia outgrowth and the timing and positioning of the sepal primordia show remarkable similarities with a developing flower in nature.

  16. Flux-based transport enhancement as a plausible unifying mechanism for auxin transport in meristem development.

    Directory of Open Access Journals (Sweden)

    Szymon Stoma

    2008-10-01

    Full Text Available Plants continuously generate new organs through the activity of populations of stem cells called meristems. The shoot apical meristem initiates leaves, flowers, and lateral meristems in highly ordered, spiralled, or whorled patterns via a process called phyllotaxis. It is commonly accepted that the active transport of the plant hormone auxin plays a major role in this process. Current hypotheses propose that cellular hormone transporters of the PIN family would create local auxin maxima at precise positions, which in turn would lead to organ initiation. To explain how auxin transporters could create hormone fluxes to distinct regions within the plant, different concepts have been proposed. A major hypothesis, canalization, proposes that the auxin transporters act by amplifying and stabilizing existing fluxes, which could be initiated, for example, by local diffusion. This convincingly explains the organised auxin fluxes during vein formation, but for the shoot apical meristem a second hypothesis was proposed, where the hormone would be systematically transported towards the areas with the highest concentrations. This implies the coexistence of two radically different mechanisms for PIN allocation in the membrane, one based on flux sensing and the other on local concentration sensing. Because these patterning processes require the interaction of hundreds of cells, it is impossible to estimate on a purely intuitive basis if a particular scenario is plausible or not. Therefore, computational modelling provides a powerful means to test this type of complex hypothesis. Here, using a dedicated computer simulation tool, we show that a flux-based polarization hypothesis is able to explain auxin transport at the shoot meristem as well, thus providing a unifying concept for the control of auxin distribution in the plant. Further experiments are now required to distinguish between flux-based polarization and other hypotheses.

  17. Repression of Lateral Organ Boundary Genes by PENNYWISE and POUND-FOOLISH Is Essential for Meristem Maintenance and Flowering in Arabidopsis.

    Science.gov (United States)

    Khan, Madiha; Ragni, Laura; Tabb, Paul; Salasini, Brenda C; Chatfield, Steven; Datla, Raju; Lock, John; Kuai, Xiahezi; Després, Charles; Proveniers, Marcel; Yongguo, Cao; Xiang, Daoquan; Morin, Halima; Rullière, Jean-Pierre; Citerne, Sylvie; Hepworth, Shelley R; Pautot, Véronique

    2015-11-01

    In the model plant Arabidopsis (Arabidopsis thaliana), endogenous and environmental signals acting on the shoot apical meristem cause acquisition of inflorescence meristem fate. This results in changed patterns of aerial development seen as the transition from making leaves to the production of flowers separated by elongated internodes. Two related BEL1-like homeobox genes, PENNYWISE (PNY) and POUND-FOOLISH (PNF), fulfill this transition. Loss of function of these genes impairs stem cell maintenance and blocks internode elongation and flowering. We show here that pny pnf apices misexpress lateral organ boundary genes BLADE-ON-PETIOLE1/2 (BOP1/2) and KNOTTED-LIKE FROM ARABIDOPSIS THALIANA6 (KNAT6) together with ARABIDOPSIS THALIANA HOMEOBOX GENE1 (ATH1). Inactivation of genes in this module fully rescues pny pnf defects. We further show that BOP1 directly activates ATH1, whereas activation of KNAT6 is indirect. The pny pnf restoration correlates with renewed accumulation of transcripts conferring floral meristem identity, including FD, SQUAMOSA PROMOTER-BINDING PROTEIN LIKE genes, LEAFY, and APETALA1. To gain insight into how this module blocks flowering, we analyzed the transcriptome of BOP1-overexpressing plants. Our data suggest a central role for the microRNA156-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE-microRNA172 module in integrating stress signals conferred in part by promotion of jasmonic acid biosynthesis. These data reveal a potential mechanism by which repression of lateral organ boundary genes by PNY-PNF is essential for flowering. © 2015 American Society of Plant Biologists. All Rights Reserved.

  18. Effects of gamma radiation on potato meristems

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Garcia Collantes, M.A.

    1976-01-01

    The development of buds in potato tubers subjected to gamma radiation at doses of 3, 6, 8 and 12 Krad is studied at histological level. The irradiation was supplied at the beguining and end of the resting period, and the irradiated buds were observed at different stages of their development. Meristem's sensitivity depends on the state of activity involved at the moment of irradiation. Different parts of the meristem present different radiosensitivity, being the most radioresistant. (author) [es

  19. 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.

  20. Revealing the importance of meristems and roots for the development of hypersensitive responses and full foliar resistance to Phytophthora infestans in the resistant potato cultivar Sarpo Mira

    DEFF Research Database (Denmark)

    Orlowska, Elzbieta Zofia; Basile, Alessio; Kandzia, Izabela

    2012-01-01

    The defence responses of potato against Phytophthora infestans were studied using the highly resistant Sarpo Mira cultivar. The effects of plant integrity, meristems, and roots on the hypersensitive response (HR), plant resistance, and the regulation of PR genes were analysed. Sarpo Mira shoots a...

  1. 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

  2. Meristem culture and subsequent micropropagation of Chilean strawberry (Fragaria chiloensis (L.) Duch.).

    Science.gov (United States)

    Quiroz, Karla A; Berríos, Miguel; Carrasco, Basilio; Retamales, Jorge B; Caligari, Peter D S; García-Gonzáles, Rolando

    2017-06-02

    Vegetative propagation of Fragaria sp. is traditionally carried out using stolons. This system of propagation, in addition to being slow, can spread plant diseases, particularly serious being viral. In vitro culture of meristems and the establishment of micropropagation protocols are important tools for solving these problems. In recent years, considerable effort has been made to develop in vitro propagation of the commercial strawberry in order to produce virus-free plants of high quality. These previous results can serve as the basis for developing in vitro-based propagation technologies in the less studied species Fragaria chiloensis. In this context, we studied the cultivation of meristems and establishment of a micropropagation protocol for F. chiloensis. The addition of polyvinylpyrrolidone (PVP) improved the meristem regeneration efficiency of F. chiloensis accessions. Similarly, the use of 6-benzylaminopurine (BAP) in the culture media increased the average rate of multiplication to 3-6 shoots per plant. In addition, the use of 6-benzylaminopurine (BAP), had low levels (near zero) of explant losses due to oxidation. However, plant height as well as number of leaves and roots were higher in media without growth regulators, with average values of 0.5 cm, 9 leaves and 4 roots per plant. For the first time in Chilean strawberry, meristem culture demonstrated to be an efficient tool for eliminating virus from infected plants, giving the possibility to produce disease free propagation material. Also, the addition of PVP into the basal MS medium improved the efficiency of plant recovery from isolated meristems. Farmers can now access to high quality plant material produced by biotech tools which will improve their technological practices.

  3. How and why does the areole meristem move in Echinocereus (Cactaceae)?

    Science.gov (United States)

    Sánchez, Daniel; Grego-Valencia, Dalia; Terrazas, Teresa; Arias, Salvador

    2015-01-01

    In Cactaceae, the areole is the organ that forms the leaves, spines and buds. Apparently, the genus Echinocereus develops enclosed buds that break through the epidermis of the stem adjacent to the areole; this trait most likely represents a synapomorphy of Echinocereus. The development of the areole is investigated here in order to understand the anatomical modifications that lead to internal bud development and to supplement anatomical knowledge of plants that do not behave according to classical shoot theory. The external morphology of the areole was documented and the anatomy was studied using tissue clearing, scanning electron microscopy and light microscopy for 50 species that represent the recognized clades and sections of the traditional classification of the genus, including Morangaya pensilis (Echinocereus pensilis). In Echinocereus, the areole is sealed by the periderm, and the areole meristem is moved and enclosed by the differential growth of the epidermis and surrounding cortex. The enclosed areole meristem is differentiated in a vegetative or floral bud, which develops internally and breaks through the epidermis of the stem. In Morangaya pensilis, the areole is not sealed by the periderm and the areole meristem is not enclosed. The enclosed areole meristem and internal bud development are understood to be an adaptation to protect the meristem and the bud from low temperatures. The anatomical evidence supports the hypothesis that the enclosed bud represents one synapomorphy for Echinocereus and also supports the exclusion of Morangaya from Echinocereus. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. The founder-cell transcriptome in the Arabidopsis apetala1 cauliflower inflorescence meristem.

    Science.gov (United States)

    Frerichs, Anneke; Thoma, Rahere; Abdallah, Ali Taleb; Frommolt, Peter; Werr, Wolfgang; Chandler, John William

    2016-11-03

    Although the pattern of lateral organ formation from apical meristems establishes species-specific plant architecture, the positional information that confers cell fate to cells as they transit to the meristem flanks where they differentiate, remains largely unknown. We have combined fluorescence-activated cell sorting and RNA-seq to characterise the cell-type-specific transcriptome at the earliest developmental time-point of lateral organ formation using DORNRÖSCHEN-LIKE::GFP to mark founder-cell populations at the periphery of the inflorescence meristem (IM) in apetala1 cauliflower double mutants, which overproliferate IMs. Within the lateral organ founder-cell population at the inflorescence meristem, floral primordium identity genes are upregulated and stem-cell identity markers are downregulated. Additional differentially expressed transcripts are involved in polarity generation and boundary formation, and in epigenetic and post-translational changes. However, only subtle transcriptional reprogramming within the global auxin network was observed. The transcriptional network of differentially expressed genes supports the hypothesis that lateral organ founder-cell specification involves the creation of polarity from the centre to the periphery of the IM and the establishment of a boundary from surrounding cells, consistent with bract initiation. However, contrary to the established paradigm that sites of auxin response maxima pre-pattern lateral organ initiation in the IM, auxin response might play a minor role in the earliest stages of lateral floral initiation.

  5. 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.

  6. 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)

  7. Effect of growth regulators in meristem culture of potato (solanum tuberosmum l.)

    International Nuclear Information System (INIS)

    Batool, A.; Zaidi, S.S.H.

    2014-01-01

    Two growth regulators, viz., Gibberellic acid (GA3) and Naphthalene acetic acid (NAA) and a combination of both (GA3 and NAA) were evaluated at three different levels (200, 300 and 400 meul) to check the growth rate of root, shoot, number of leaves and nodes of potato plantlets in two potato varieties, namely cardinal and SH-5, grown by meristem culture. Analysis of variance revealed highly significant differences between varieties, hormones and their interaction for all the studied traits. Mean values revealed that among two varieties Cardinal produced root length (0.70 cm), shoot length (2.50 cm), number of leaves (6.96) and number of nodes (8) are better than the SH-5 which produced root length (0.54 cm), shoot length (1.38 cm), number of leaves (4.29) and number of nodes (5.3). The variety cardinal and GA3 at 300 meul followed by 200 meul produced most suitable results. By using the concentration of 300 meul maximum root length of (1.40 cm), shoot length of (3.43 cm), number of leaves (10) and no of nodes (11) was obtained. At 200 meul, though root and shoot length obtained was very similar at 300 meul but produced less number of leaves and nodes. (author)

  8. 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.

  9. Meristem Culture of Aloe vera L

    International Nuclear Information System (INIS)

    Kay Thi Mya; Thida Myint; Myo Han; Khin Maung Sein

    2005-10-01

    Shoot tips of Aloe vera L were excised and inoculated in basal and modified MS (Murashige and Skoog, 1962) medium. Growth regulators and growth factors were supplemented to the basal medium. Development of explants, initiation of callus and multiplication of shoots in culture were recorded.

  10. Potential Bud Bank Responses to Apical Meristem Damage and Environmental Variables: Matching or Complementing Axillary Meristems?

    Czech Academy of Sciences Publication Activity Database

    Klimešová, Jitka; Malíková, Lenka; Rosenthal, J.; Šmilauer, P.

    2014-01-01

    Roč. 9, č. 2 (2014), e88093 E-ISSN 1932-6203 R&D Projects: GA ČR GPP504/12/P540; GA ČR GA526/09/0963 Institutional support: RVO:67985939 Keywords : bud bank * axillary meristem * disturbance Subject RIV: EH - Ecology, Behaviour Impact factor: 3.234, year: 2014

  11. Root developmental programs shape the Medicago truncatula nodule meristem

    NARCIS (Netherlands)

    Franssen, H.; Xiao, T.T.; Kulikova, O.; Wan, X.; Bisseling, T.; Scheres, B.; Heidstra, R.

    2015-01-01

    Nodules on the roots of legume plants host nitrogen-fixing Rhizobium bacteria. Several lines of evidence indicate that nodules are evolutionarily related to roots. We determined whether developmental control of the Medicago truncatula nodule meristem bears resemblance to that in root meristems

  12. 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...

  13. Brachytic2/ZmABCB1 functions in IAA export from intercalary meristems

    Science.gov (United States)

    Knöller, Anne Sophie; Richards, Elizabeth L.; Peer, Wendy Ann; Murphy, Angus S.

    2010-01-01

    Dwarfism traits in Zea mays are regulated by multiple factors including the hormone auxin. Dwarf brachytic2 (br2) mutants harbour lesions in the gene encoding an orthologue of Arabidopsis thaliana ABCB1 which functions in auxin efflux out of meristematic regions in the shoot and root. br2 mesocotyls and coleoptiles exhibit reduced auxin transport. However, the dwarf stature of br2 derives from shortened lower internodes whilst the upper portion of the plant is completely normal. As such, it is counter-intuitive to attribute br2 dwarfism exclusively to reduced auxin export out of the shoot apex. Arabidopsis abcb1 mutants exhibit only minor reductions in auxin transport and plant height unless combined with mutations in the ABCB19 auxin transporter. Phylogenetic modelling analysis excludes the possibility that BR2 is more closely related to ABCB19 which has three more closely related orthologues in maize. BR2 is expressed in nodal meristems, and analyses of auxin transport and content indicate that BR2 function in these grass-specific tissues is analogous to ABCB1 function in the shoot and root apex of Arabidopsis. These results indicate that ABCB1/BR2 function is conserved between dicots and monocots, but also suggests that this function must be understood in the context of the segmental organization of grass plants. PMID:20581123

  14. Differential TOR activation and cell proliferation in Arabidopsis root and shoot apexes.

    Science.gov (United States)

    Li, Xiaojuan; Cai, Wenguo; Liu, Yanlin; Li, Hui; Fu, Liwen; Liu, Zengyu; Xu, Lin; Liu, Hongtao; Xu, Tongda; Xiong, Yan

    2017-03-07

    The developmental plasticity of plants relies on the remarkable ability of the meristems to integrate nutrient and energy availability with environmental signals. Meristems in root and shoot apexes share highly similar molecular players but are spatially separated by soil. Whether and how these two meristematic tissues have differential activation requirements for local nutrient, hormone, and environmental cues (e.g., light) remain enigmatic in photosynthetic plants. Here, we report that the activation of root and shoot apexes relies on distinct glucose and light signals. Glucose energy signaling is sufficient to activate target of rapamycin (TOR) kinase in root apexes. In contrast, both the glucose and light signals are required for TOR activation in shoot apexes. Strikingly, exogenously applied auxin is able to replace light to activate TOR in shoot apexes and promote true leaf development. A relatively low concentration of auxin in the shoot and high concentration of auxin in the root might be responsible for this distinctive light requirement in root and shoot apexes, because light is required to promote auxin biosynthesis in the shoot. Furthermore, we reveal that the small GTPase Rho-related protein 2 (ROP2) transduces light-auxin signal to activate TOR by direct interaction, which, in turn, promotes transcription factors E2Fa,b for activating cell cycle genes in shoot apexes. Consistently, constitutively activated ROP2 plants stimulate TOR in the shoot apex and cause true leaf development even without light. Together, our findings establish a pivotal hub role of TOR signaling in integrating different environmental signals to regulate distinct developmental transition and growth in the shoot and root.

  15. Molecular cloning, phylogenetic analysis, and expression patterns of LATERAL SUPPRESSOR-LIKE and REGULATOR OF AXILLARY MERISTEM FORMATION-LIKE genes in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Fambrini, Marco; Salvini, Mariangela; Pugliesi, Claudio

    2017-03-01

    The wild sunflower (Helianthus annuus) plants develop a highly branched form with numerous small flowering heads. The origin of a no branched sunflower, producing a single large head, has been a key event in the domestication process of this species. The interaction between hormonal factors and several genes organizes the initiation and outgrowth of axillary meristems (AMs). From sunflower, we have isolated two genes putatively involved in this process, LATERAL SUPPRESSOR (LS)-LIKE (Ha-LSL) and REGULATOR OF AXILLARY MERISTEM FORMATION (ROX)-LIKE (Ha-ROXL), encoding for a GRAS and a bHLH transcription factor (TF), respectively. Typical amino acid residues and phylogenetic analyses suggest that Ha-LSL and Ha-ROXL are the orthologs of the branching regulator LS and ROX/LAX1, involved in the growth habit of both dicot and monocot species. qRT-PCR analyses revealed a high accumulation of Ha-LSL transcripts in roots, vegetative shoots, and inflorescence shoots. By contrast, in internodal stems and young leaves, a lower amount of Ha-LSL transcripts was observed. A comparison of transcription patterns between Ha-LSL and Ha-ROXL revealed some analogies but also remarkable differences; in fact, the gene Ha-ROXL displayed a low expression level in all organs analyzed. In situ hybridization (ISH) analysis showed that Ha-ROXL transcription was strongly restricted to a small domain within the boundary zone separating the shoot apical meristem (SAM) and the leaf primordia and in restricted regions of the inflorescence meristem, beforehand the separation of floral bracts from disc flower primordia. These results suggested that Ha-ROXL may be involved to establish a cell niche for the initiation of AMs as well as flower primordia. The accumulation of Ha-LSL transcripts was not restricted to the boundary zones in vegetative and inflorescence shoots, but the mRNA activity was expanded in other cellular domains of primary shoot apical meristem as well as AMs. In addition, Ha

  16. Transcript profiling of cytokinin action in Arabidopsis roots and shoots discovers largely similar but also organ-specific responses

    Directory of Open Access Journals (Sweden)

    Brenner Wolfram G

    2012-07-01

    Full Text Available Abstract Background The plant hormone cytokinin regulates growth and development of roots and shoots in opposite ways. In shoots it is a positive growth regulator whereas it inhibits growth in roots. It may be assumed that organ-specific regulation of gene expression is involved in these differential activities, but little is known about it. To get more insight into the transcriptional events triggered by cytokinin in roots and shoots, we studied genome-wide gene expression in cytokinin-treated and cytokinin-deficient roots and shoots. Results It was found by principal component analysis of the transcriptomic data that the immediate-early response to a cytokinin stimulus differs from the later response, and that the transcriptome of cytokinin-deficient plants is different from both the early and the late cytokinin induction response. A higher cytokinin status in the roots activated the expression of numerous genes normally expressed predominantly in the shoot, while a lower cytokinin status in the shoot reduced the expression of genes normally more active in the shoot to a more root-like level. This shift predominantly affected nuclear genes encoding plastid proteins. An organ-specific regulation was assigned to a number of genes previously known to react to a cytokinin signal, including root-specificity for the cytokinin hydroxylase gene CYP735A2 and shoot specificity for the cell cycle regulator gene CDKA;1. Numerous cytokinin-regulated genes were newly discovered or confirmed, including the meristem regulator genes SHEPHERD and CLAVATA1, auxin-related genes (IAA7, IAA13, AXR1, PIN2, PID, several genes involved in brassinosteroid (CYP710A1, CYP710A2, DIM/DWF and flavonol (MYB12, CHS, FLS1 synthesis, various transporter genes (e.g. HKT1, numerous members of the AP2/ERF transcription factor gene family, genes involved in light signalling (PhyA, COP1, SPA1, and more than 80 ribosomal genes. However, contrasting with the fundamental difference of

  17. Identity's identities

    DEFF Research Database (Denmark)

    Jensen, Kim Ebensgaard

    -specialized language in which it also serves a number of functions – some of which are quite fundamental to society as such. In other words, the lexeme identity is a polysemic word and has multiple, well, identities. Given that it appears to have a number of functions in a variety of registers, including terminologies...... in Academic English and more everyday-based English, identity as a lexeme is definitely worth having a look at. This paper presents a lexicological study of identity in which some of its senses are identified and their behaviors in actual discourse are observed. Drawing on data from the 2011 section...... of the Corpus of Contemporary American English, a behavioral profile of the distributional characteristics of identity is set up. Behavioral profiling is a lexicographical method developed by the corpus linguist Stefan Th. Gries which, by applying semantic ID tagging and statistical analysis, provides a fine...

  18. Gibberellin mediates daylength-controlled differentiation of vegetative meristems in strawberry (Fragaria × ananassa Duch

    Directory of Open Access Journals (Sweden)

    Moritz Thomas

    2009-02-01

    Full Text Available Abstract Background Differentiation of long and short shoots is an important developmental trait in several species of the Rosaceae family. However, the physiological mechanisms controlling this differentiation are largely unknown. We have studied the role of gibberellin (GA in regulation of shoot differentiation in strawberry (Fragaria × ananassa Duch. cv. Korona. In strawberry, differentiation of axillary buds to runners (long shoot or to crown branches (short shoot is promoted by long-day and short-day conditions, respectively. Formation of crown branches is a prerequisite for satisfactory flowering because inflorescences are formed from the apical meristems of the crown. Results We found that both prohexadione-calcium and short photoperiod inhibited runner initiation and consequently led to induction of crown branching. In both cases, this correlated with a similar decline in GA1 level. Exogenous GA3 completely reversed the effect of prohexadione-calcium in a long photoperiod, but was only marginally effective in short-day grown plants. However, transfer of GA3-treated plants from short days to long days restored the normal runner formation. This did not occur in plants that were not treated with GA3. We also studied GA signalling homeostasis and found that the expression levels of several GA biosynthetic, signalling and target genes were similarly affected by prohexadione-calcium and short photoperiod in runner tips and axillary buds, respectively. Conclusion GA is needed for runner initiation in strawberry, and the inhibition of GA biosynthesis leads to the formation of crown branches. Our findings of similar changes in GA levels and in GA signalling homeostasis after prohexadione-calcium and short-day treatments, and photoperiod-dependent responsiveness of the axillary buds to GA indicate that GA plays a role also in the photoperiod-regulated differentiation of axillary buds. We propose that tightly regulated GA activity may control

  19. Clonal multiplication of Cymbidiums through tissue culture of the shoot meristem

    Energy Technology Data Exchange (ETDEWEB)

    Wimber, Donald E.

    1963-09-01

    The propagation of clonal varieties of some orchids is at times exasperatingly slow and occasionally an almost futile effort. Clonal multiplication is generally confined to dlvidlng mature plants and to starting plants from pseudobulbs. There is, of course, the specialized technique for obtaining Phalaenopsis plantlets from the aseptic culture of inflorescence nodes, but this is basically the same thing as propagating plants from pseudobulbs. In certain cases it is highly desirable to rapidly multiply certain clones of orchids. Awarded varieties could thereby be dispersed with great rapidity where now it may take decades for some clones to became fairly common. Commercial flower production would be very much enhanced if certain desirable clones could be multiplied ad infinitum within a short time. Orchid flower production could then be placed more on a par with many of the other cut flowers and the clonal peculiarities of some fo the current hybrids could be pampered instead of ignored. This paper describes a tissue culture method for the rapid propagation of Cymbidium clones.

  20. Shoot apical meristem and plant body organization: a cross-species comparative study

    Czech Academy of Sciences Publication Activity Database

    Schnablová, Renáta; Herben, Tomáš; Klimešová, Jitka

    2017-01-01

    Roč. 120, č. 5 (2017), s. 833-843 ISSN 0305-7364 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : Corner's rule * cell number * cell size Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 4.041, year: 2016

  1. 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

  2. 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)

  3. Unique and Conserved Features of the Barley Root Meristem

    Directory of Open Access Journals (Sweden)

    Gwendolyn K. Kirschner

    2017-07-01

    Full Text Available Plant root growth is enabled by root meristems that harbor the stem cell niches as a source of progenitors for the different root tissues. Understanding the root development of diverse plant species is important to be able to control root growth in order to gain better performances of crop plants. In this study, we analyzed the root meristem of the fourth most abundant crop plant, barley (Hordeum vulgare. Cell division studies revealed that the barley stem cell niche comprises a Quiescent Center (QC of around 30 cells with low mitotic activity. The surrounding stem cells contribute to root growth through the production of new cells that are displaced from the meristem, elongate and differentiate into specialized root tissues. The distal stem cells produce the root cap and lateral root cap cells, while cells lateral to the QC generate the epidermis, as it is typical for monocots. Endodermis and inner cortex are derived from one common initial lateral to the QC, while the outer cortex cell layers are derived from a distinct stem cell. In rice and Arabidopsis, meristem homeostasis is achieved through feedback signaling from differentiated cells involving peptides of the CLE family. Application of synthetic CLE40 orthologous peptide from barley promotes meristem cell differentiation, similar to rice and Arabidopsis. However, in contrast to Arabidopsis, the columella stem cells do not respond to the CLE40 peptide, indicating that distinct mechanisms control columella cell fate in monocot and dicot plants.

  4. 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.

  5. Sugar-Mediated Acclimation: The Importance of Sucrose Metabolism in Meristems

    NARCIS (Netherlands)

    Carpentier, S.C.; Vertommen, A.; Swennen, R.; Witters, E.; Fortes, C.; Souza, M.T.; Panis, B.

    2010-01-01

    We have designed an in vitro experimental setup to study the role of sucrose in sugar-mediated acclimation of banana meristems using established highly proliferating meristem cultures. It is a first step toward the systems biology of a meristem and the understanding of how it can survive severe

  6. Analysis of Transcriptional Responses of the Inflorescence Meristems in Jatropha curcas Following Gibberellin Treatment

    Directory of Open Access Journals (Sweden)

    Wen-Kai Hui

    2018-02-01

    Full Text Available Jatropha curcas L. seeds an oilseed plant with great potential for biodiesel production. However, low seed yield, which was limited by its lower female flowers, was a major drawback for its utilization. Our previous study found that the flower number and female-to-male ratio were increased by gibberellin treatment. Here, we compared the transcriptomic profiles of inflorescence meristem at different time points after gibberellic acid A3 (GA3 treatment. The present study showed that 951 differentially expressed genes were obtained in response to gibberellin treatment, compared with control samples. The 6-h time point was an important phase in the response to exogenous gibberellin. Furthermore, the plant endogenous gibberellin, auxin, ethylene, abscisic acid, and brassinolide-signaling transduction pathways were repressed, whereas the genes associated with cytokinin and jasmonic acid signaling were upregulated for 24-h time point following GA3 treatment. In addition, the floral meristem determinacy genes (JcLFY, JcSOC1 and floral organ identity genes (JcAP3, JcPI, JcSEP1-3 were significantly upregulated, but their negative regulator (JcSVP was downregulated after GA3 treatment. Moreover, the effects of phytohormone, which was induced by exogenous plant growth regulator, mainly acted on the female floral differentiation process. To the best of our knowledge, this data is the first comprehensive analysis of the underlying transcriptional response mechanism of floral differentiation following GA3 treatment in J. curcas, which helps in engineering high-yielding varieties of Jatropha.

  7. 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)

  8. Comparison of Meristem Culture and Heat Therapy to Clean Garlic ...

    African Journals Online (AJOL)

    (meristem culture) እንዱሁም ከሶስቱም ዝርያዎች በቫይረስ የተበከለ ኮረቶችን በሙቀት ... Eastern and Central Africa-International Livestock Research Institute Hub ...

  9. N-MYC down-regulated-like proteins regulate meristem initiation by modulating auxin transport and MAX2 expression.

    Science.gov (United States)

    Mudgil, Yashwanti; Ghawana, Sanjay; Jones, Alan M

    2013-01-01

    N-MYC down-regulated-like (NDL) proteins interact with the Gβ subunit (AGB1) of the heterotrimeric G protein complex and play an important role in AGB1-dependent regulation of lateral root formation by affecting root auxin transport, auxin gradients and the steady-state levels of mRNA encoding the PIN-FORMED 2 and AUXIN 1 auxin transport facilitators. Auxin transport in aerial tissue follows different paths and utilizes different transporters than in roots; therefore, in the present study, we analyzed whether NDL proteins play an important role in AGB1-dependent, auxin-mediated meristem development. Expression levels of NDL gene family members need to be tightly regulated, and altered expression (both over-expression and down-regulation) confers ectopic growth. Over-expression of NDL1 disrupts vegetative and reproductive organ development. Reduced expression of the NDL gene family members results in asymmetric leaf emergence, twinning of rosette leaves, defects in leaf formation, and abnormal silique distribution. Reduced expression of the NDL genes in the agb1-2 (null allele) mutant rescues some of the abnormal phenotypes, such as silique morphology, silique distribution, and peduncle angle, suggesting that proper levels of NDL proteins are maintained by AGB1. We found that all of these abnormal aerial phenotypes due to altered NDL expression were associated with increases in basipetal auxin transport, altered auxin maxima and altered MAX2 expression within the inflorescence stem. NDL proteins, together with AGB1, act as positive regulators of meristem initiation and branching. AGB1 and NDL1 positively regulate basipetal inflorescence auxin transport and modulate MAX2 expression in shoots, which in turn regulates organ and lateral meristem formation by the establishment and maintenance of auxin gradients.

  10. N-MYC down-regulated-like proteins regulate meristem initiation by modulating auxin transport and MAX2 expression.

    Directory of Open Access Journals (Sweden)

    Yashwanti Mudgil

    Full Text Available N-MYC down-regulated-like (NDL proteins interact with the Gβ subunit (AGB1 of the heterotrimeric G protein complex and play an important role in AGB1-dependent regulation of lateral root formation by affecting root auxin transport, auxin gradients and the steady-state levels of mRNA encoding the PIN-FORMED 2 and AUXIN 1 auxin transport facilitators. Auxin transport in aerial tissue follows different paths and utilizes different transporters than in roots; therefore, in the present study, we analyzed whether NDL proteins play an important role in AGB1-dependent, auxin-mediated meristem development.Expression levels of NDL gene family members need to be tightly regulated, and altered expression (both over-expression and down-regulation confers ectopic growth. Over-expression of NDL1 disrupts vegetative and reproductive organ development. Reduced expression of the NDL gene family members results in asymmetric leaf emergence, twinning of rosette leaves, defects in leaf formation, and abnormal silique distribution. Reduced expression of the NDL genes in the agb1-2 (null allele mutant rescues some of the abnormal phenotypes, such as silique morphology, silique distribution, and peduncle angle, suggesting that proper levels of NDL proteins are maintained by AGB1. We found that all of these abnormal aerial phenotypes due to altered NDL expression were associated with increases in basipetal auxin transport, altered auxin maxima and altered MAX2 expression within the inflorescence stem.NDL proteins, together with AGB1, act as positive regulators of meristem initiation and branching. AGB1 and NDL1 positively regulate basipetal inflorescence auxin transport and modulate MAX2 expression in shoots, which in turn regulates organ and lateral meristem formation by the establishment and maintenance of auxin gradients.

  11. 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.

  12. 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

  13. 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…

  14. Transformation of Inhibitor of Meristem Activity (IMA Gene into Jatropha curcas L.

    Directory of Open Access Journals (Sweden)

    Asri Pirade Paserang

    2015-09-01

    Full Text Available Jatropha is one of the many biodiesel plants developed in tropical countries. Efforts to increase its productivity can be done using various methods of breeding. One of the breeding methods is the introduction of genes into the Jatropha plant. The aim of this study is to assess the success of genetic transformation using the Inhibitor of Meristem Activity (IMA gene in Jatropha curcas. The research procedures included inoculation of explants with Agrobacterium tumefaciens, callus induction, screening test of selection media, regeneration, and gene expression analysis using Polymerase Chain Reaction (PCR. IMA is one of the genes that controls flowering genes and ovule development. It was first isolated from tomato plants and has been successfully overexpressed in these plants using the Cauliflower Mosaic Virus (CaMV 35S promoter. In this experiment, plant transformation was performed on J. curcas as the target. Explant callus formation in both the control and treated samples was good, but shoot formation decreased dramatically in the treated explants. PCR analysis indicated that IMA genes can be inserted into J. curcas with the size of the IMA gene is 500 bp.

  15. 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.

  16. Analysis of the Arabidopsis superman allelic series and the interactions with other genes demonstrate developmental robustness and joint specification of male-female boundary, flower meristem termination and carpel compartmentalization.

    Science.gov (United States)

    Breuil-Broyer, Stéphanie; Trehin, Christophe; Morel, Patrice; Boltz, Véronique; Sun, Bo; Chambrier, Pierre; Ito, Toshiro; Negrutiu, Ioan

    2016-04-01

    SUPERMAN is a cadastral gene controlling the sexual boundary in the flower. The gene's functions and role in flower development and evolution have remained elusive. The analysis of a contrasting SUP allelic series (for which the names superman, superwoman and supersex have been coined) makes it possible to distinguish early vs. late regulatory processes at the flower meristem centre to which SUP is an important contributor. Their understanding is essential in further addressing evolutionary questions linking bisexuality and flower meristem homeostasis. Inter-allelic comparisons were carried out and SUP interactions with other boundary factors and flower meristem patterning and homeostasis regulators (such as CLV, WUS, PAN, CUC, KNU, AG, AP3/PI, CRC and SPT) have been evaluated at genetic, molecular, morphological and histological levels. Early SUP functions include mechanisms of male-female (sexual) boundary specification, flower mersitem termination and control of stamen number. A SUP-dependent flower meristem termination pathway is identified and analysed. Late SUP functions play a role in organ morphogenesis by controlling intra-whorl organ separation and carpel medial region formation. By integrating early and late SUP functions, and by analyzing in one single experiment a series of SUP genetic interactions, the concept of meristematic 'transference' (cascade) - a regulatory bridging process redundantly and sequentially co-ordinating the triggering and completion of flower meristem termination, and carpel margin meristem and placenta patterning - is proposed. Taken together, the results strongly support the view that SUP(-type) function(s) have been instrumental in resolving male/female gradients into sharp male and female identities (whorls, organs) and in enforcing flower homeostasis during evolution. This has probably been achieved by incorporating the meristem patterning system of the floral axis into the female/carpel programme. © The Author 2016

  17. Combined impact of water column oxygen and temperature on internal oxygen status and growth of Zostera marina seedlings and adult shoots

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl; Borum, Jens

    2013-01-01

    Eelgrass (Zostera marina L.) occasionally experiences severe die-offs during warm summer periods with variable water column oxygen partial pressures (pO). Eelgrass is known to be very intolerant to tissue anoxia with reduced growth and increasing mortality after ≤12h anoxia in the dark...... at temperatures of ≥25°C. In the present study we experimentally examine the impact of combined water column oxygen and temperature on oxygen dynamics in leaf meristems of seedlings and adult shoots to better understand how stressful environmental conditions affect eelgrass oxygen dynamics and subsequent growth...... and mortality. There was a strong interaction between water column oxygen and temperature on meristem pO implying that eelgrass is rather resistant to unfavorable oxygen conditions in winter but becomes increasingly vulnerable in summer, especially at high temperatures. At 25°C meristems became anoxic...

  18. Ds tagging of BRANCHED FLORETLESS 1 (BFL1 that mediates the transition from spikelet to floret meristem in rice (Oryza sativa L

    Directory of Open Access Journals (Sweden)

    Hoque Mohammad

    2003-09-01

    Full Text Available Abstract Background The genetics of spikelet formation, a feature unique to grasses such as rice and maize, is yet to be fully understood, although a number of meristem and organ identity mutants have been isolated and investigated in Arabidopsis and maize. Using a two-element Ac/Ds transposon tagging system we have isolated a rice mutant, designated branched floretless 1 (bfl1 which is defective in the transition from spikelet meristem to floret meristem. Results The bfl1 mutant shows normal differentiation of the primary rachis-branches leading to initial spikelet meristem (bract-like structure equivalent to rudimentary glumes formation but fails to develop empty glumes and florets. Instead, axillary meristems in the bract-like structure produce sequential alternate branching, thus resulting in a coral shaped morphology of the branches in the developing panicle. The bfl1 mutant harbours a single Ds insertion in the upstream region of the BFL1 gene on chromosome 7 corresponding to PAC clone P0625E02 (GenBank Acc No. message URL http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=nucleotide&list_uids=34395191&dopt=GenBank&term=ap004570AP004570. RT-PCR analyses revealed a drastic reduction of BFL1 transcript levels in the bfl1 mutant compared to that in the wild-type. In each of the normal panicle-bearing progeny plants, from occasional revertant seeds of the vegetatively-propagated mutant plant, Ds was shown to be excised from the bfl1 locus. BFL1 contains an EREBP/AP2 domain and is most likely an ortholog of the maize transcription factor gene BRANCHED SILKLESS1 (BD1. Conclusions bfl1 is a Ds-tagged rice mutant defective in the transition from spikelet meristem (SM to floret meristem (FM. BFL1 is most probably a rice ortholog of the maize ERF (EREBP/AP2 transcription factor gene BD1. Based on the similarities in mutant phenotypes bfl1 is likely to be an allele of the previously reported frizzy panicle locus.

  19. 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.)

  20. 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.

  1. 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 ...

  2. Phytoplasmal infection derails genetically preprogrammed meristem fate and alters plant architecture

    OpenAIRE

    Wei, Wei; Davis, Robert Edward; Nuss, Donald L.; Zhao, Yan

    2013-01-01

    In higher plants, the destiny of apical meristems (stem cells) is specific organogenesis, which determines the pattern of plant growth, and therefore morphotype and fertility. We found that bacterial infection can derail the meristems from their genetically preprogrammed destiny, altering plant morphogenesis. We identified four abnormal growth patterns, symptoms, in tomato infected with a cell wall-less bacterium, and found that each symptom corresponds to a distinct phase in meristem fate de...

  3. Clonal analysis of corn plant development. I. The development of the tassel and the ear shoot

    International Nuclear Information System (INIS)

    Johri, M.M.; Coe, E.H. Jr.

    1983-01-01

    The development of the tassel and the ear shoot has been investigated in corn (Zea mays L.). X irradiation of dry kernels and seedlings heterozygous for anthocyanin markers or for factors altering tassel and ear morphology results in the formation of clones (sectors) from cells of the apical meristem. Most tassels develop from 4 +/- 1 cells of the mature embryo. The expression of ramosa-1, tunicate, tassel seed-6, and vestigial is cell autonomous in the tassel. These genes act late in development and modify the developmental fate or decision of an individual clone and not of the whole group of cells producing a tassel. The ear shoot develops from lineages of one to three cells derived each from the L-I (outmost cell layer) and L-II (second cell layer) of the apical meristem. Typically the clones start in the ear shoot (in the husks and possibly in the cob), extend upward in an internode, continue along the margin of the leaf sheath or leaf blade at the node above, and terminate in this or the next higher leaf. The separation of lineages for ear shoot and internode occurs in the period around 13 days after sowing. The analysis of clonal boundaries shows that a small number of embryonic cells become isolated in their developmental capacity. This commitment process appears to be analogous to the process of compartmentation in the imaginal disks of fruit flies. The extent of proliferation of individual cells within a group of highly flexible and any particular clone does not generate a specific part of a tassel or an ear shoot. There must be cellular communication between various clones so that the overall size and morphology of an organ remain normal and more or less fixed. Thus the process of development in plants is also highly regulative in nature and shares many features in common with development in fruit flies

  4. optimization of protocol for m apical meristem of embryonic axes

    African Journals Online (AJOL)

    userpc

    The hypocotyl segments, prima were removed and embryonic axes were placed in culture bott nd Skoog basal + B5 vitamins (MSB5) fortified with 22.2µM, 26.6µM opurine (BAP) to induce multiple shoots. Elongated shoots we tion media consisting of MSB5 supplemented with low concentrati one free media promoted direct ...

  5. ABNORMAL INFLORESCENCE MERISTEM1 Functions in Salicylic Acid Biosynthesis to Maintain Proper Reactive Oxygen Species Levels for Root Meristem Activity in Rice.

    Science.gov (United States)

    Xu, Lei; Zhao, Hongyu; Ruan, Wenyuan; Deng, Minjuan; Wang, Fang; Peng, Jinrong; Luo, Jie; Chen, Zhixiang; Yi, Keke

    2017-03-01

    Root meristem activity determines root growth and root architecture and consequently affects water and nutrient uptake in plants. However, our knowledge about the regulation of root meristem activity in crop plants is very limited. Here, we report the isolation and characterization of a short root mutant in rice ( Oryza sativa ) with reduced root meristem activity. This root growth defect is caused by a mutation in ABNORMAL INFLORESCENCE MERISTEM1 ( AIM1 ), which encodes a 3-hydroxyacyl-CoA dehydrogenase, an enzyme involved in β-oxidation. The reduced root meristem activity of aim1 results from reduced salicylic acid (SA) levels and can be rescued by SA application. Furthermore, reduced SA levels are associated with reduced levels of reactive oxygen species (ROS) in aim1 , likely due to increased expression of redox and ROS-scavenging-related genes, whose increased expression is (at least in part) caused by reduced expression of the SA-inducible transcriptional repressors WRKY62 and WRKY76. Like SA, ROS application substantially increased root length and root meristem activity in aim1 These results suggest that AIM1 is required for root growth in rice due to its critical role in SA biosynthesis: SA maintains root meristem activity through promoting ROS accumulation by inducing the activity of WRKY transcriptional repressors, which repress the expression of redox and ROS-scavenging genes. © 2017 American Society of Plant Biologists. All rights reserved.

  6. Cadmium cytotoxity: study of Allium sativum L. root meristems

    Energy Technology Data Exchange (ETDEWEB)

    Clain, E.; Deysson, G.

    1976-01-01

    Three cadmium salts, CdSO/sub 4/, Cd(NO/sub 3/)/sub 2/, and Cd(OAc)/sub 2/ were tested on garlic root meristems. CdSO/sub 4/ was the most toxic of the three; when 10/sup -7/ mol/ml was used, mitostasis resulted within 24 hours and cellular death after forty-eight hours. Cd(NO/sub 3/)/sub 2/ and Cd(OAc)/sub 2/ were lethal at 5 x 10/sup -7/ mol/ml. 1 figure, 1 table.

  7. Plant-specific Histone Deacetylases HDT½ Regulate GIBBERELLIN 2-OXIDASE 2 Expression to Control Arabidopsis Root Meristem Cell Number

    KAUST Repository

    Li, Huchen; Torres-Garcia, Jesus; latrasse, David; Benhamed, Moussa; Schilderink, Stefan; Zhou, Wenkun; Kulikova, Olga; Hirt, Heribert; Bisseling, Ton

    2017-01-01

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription

  8. 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

  9. Effects of anxiety on handgun shooting behavior of police officers: A pilot study

    NARCIS (Netherlands)

    Nieuwenhuys, A.; Oudejans, R.R.D.

    2010-01-01

    The current pilot study aimed at providing an initial assessment of how anxiety influences police officers' shooting behavior. Seven police officers participated and completed an identical shooting exercise under two experimental conditions: low anxiety, against a non-threatening opponent, and high

  10. 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…

  11. Transcriptome of the inflorescence meristems of the biofuel plant Jatropha curcas treated with cytokinin.

    Science.gov (United States)

    Pan, Bang-Zhen; Chen, Mao-Sheng; Ni, Jun; Xu, Zeng-Fu

    2014-11-17

    Jatropha curcas, whose seed content is approximately 30-40% oil, is an ideal feedstock for producing biodiesel and bio-jet fuels. However, Jatropha plants have a low number of female flowers, which results in low seed yield that cannot meet the needs of the biofuel industry. Thus, increasing the number of female flowers is critical for the improvement of Jatropha seed yield. Our previous findings showed that cytokinin treatment can increase the flower number and female to male ratio and also induce bisexual flowers in Jatropha. The mechanisms underlying the influence of cytokinin on Jatropha flower development and sex determination, however, have not been clarified. This study examined the transcriptional levels of genes involved in the response to cytokinin in Jatropha inflorescence meristems at different time points after cytokinin treatment by 454 sequencing, which gave rise to a total of 294.6 Mb of transcript sequences. Up-regulated and down-regulated annotated and novel genes were identified, and the expression levels of the genes of interest were confirmed by qRT-PCR. The identified transcripts include those encoding genes involved in the biosynthesis, metabolism, and signaling of cytokinin and other plant hormones, flower development and cell division, which may be related to phenotypic changes of Jatropha in response to cytokinin treatment. Our analysis indicated that Jatropha orthologs of the floral organ identity genes known as ABCE model genes, JcAP1,2, JcPI, JcAG, and JcSEP1,2,3, were all significantly repressed, with an exception of one B-function gene JcAP3 that was shown to be up-regulated by BA treatment, indicating different mechanisms to be involved in the floral organ development of unisexual flowers of Jatropha and bisexual flowers of Arabidopsis. Several cell division-related genes, including JcCycA3;2, JcCycD3;1, JcCycD3;2 and JcTSO1, were up-regulated, which may contribute to the increased flower number after cytokinin treatment. This study

  12. The effects of γ-ray irradiation on the cellular and subcellular structures of apical meristem in garlic (Allium sativum) and onion (Allium cepal)

    International Nuclear Information System (INIS)

    Xi Yufang; Qian Dongmei; Bian Qijun; Ying Tiejin

    1993-01-01

    Electronic microscopic study revealed that 2 ∼ 30 krads of γ-ray irradiation to garlic and onion could cause various damages to cellular and subcellular structures of the shoot apical meristem. Among the various oganelles, the vacuoles showed the highest radio-sensitivity while mitochondria and nucleus seemed to be most resistant to irradiation. The irradiated cells did not show any visible structural damages until the dormancy ended, suggesting that metabolism played an important role in the structural damages. The study also suggested that even after the irradiation which caused intensive subcellular structural damages, the tissues could survive. However, the potency of mitosis in the apex was lost, resulting in the inhibition of sprouting

  13. [ipomoea batatas (l.) lam] by meristem culture and thermotherapy

    African Journals Online (AJOL)

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    infection, Hawassa Agricultural Research Centre ... personal communication). ... Production of disease-free planting material by ... into sterile Magenta boxes for multiplication and ... added to MS medium (E) and multiple shoot growth of Awassa-83 in 2 mg/l BAP added to MS ..... Africa. DFID crop protection program, a paper.

  14. Depletion of cellular brassinolide decreases embryo production and disrupts the architecture of the apical meristems in Brassica napus microspore-derived embryos.

    Science.gov (United States)

    Belmonte, Mark; Elhiti, Mohamed; Waldner, Blaine; Stasolla, Claudio

    2010-06-01

    Exogenous applications of brassinolide (BL) increased the number and quality of microspore-derived embryos (MDEs) whereas treatments with brassinazole (BrZ), a BL biosynthetic inhibitor, had the opposite effect. At the optimal concentration (4x10(-6) M) BrZ decreased both embryo yield and conversion to less than half the value of control embryos. Metabolic studies revealed that BL levels had profound effects on glutathione and ascorbate metabolism by altering the amounts of their reduced forms (ASC and GSH) and oxidized forms [dehydroascorbate (DHA), ascorbate free radicals (AFRs), and GSSG]. Applications of BL switched the glutathione and ascorbate pools towards the oxidized forms, thereby lowering the ASC/ASC+DHA+AFR and GSH/GSH+GSSG ratios. These changes were ascribed to the ability of BL to increase the activity of ascorbate peroxidase (APX) and decrease that of glutathione reductase (GR). This trend was reversed in a BL-depleted environment, effected by BrZ applications. These metabolic alterations were associated with changes in embryo structure and performance. BL-treated MDEs developed zygotic-like shoot apical meristems (SAMs) whereas embryos treated with BrZ developed abnormal meristems. In the presence of BrZ, embryos either lacked a visible SAM, or formed SAMs in which the meristematic cells showed signs of differentiation, such as vacuolation and storage product accumulation. These abnormalities were accompanied by the lack or misexpression of three meristem marker genes isolated from Brassica napus (denoted as BnSTM, BnCLV1, and BnZLL-1) homologous to the Arabidopsis SHOOTMERISTEMLESS (STM), CLAVATA 1 (CLV1), and ZWILLE (ZLL). The expression of BnSTM and BnCLV1 increased after a few days in cultures in embryos treated with BL whereas an opposite tendency was observed with applications of BrZ. Compared with control embryos where these two genes exhibited abnormal localization patterns, BnSTM and BnCLV1 always localized throughout the subapical domains

  15. Meristem micropropagation of cassava (Manihot esculenta) evokes genome-wide changes in DNA methylation

    OpenAIRE

    Shedrack Reuben Kitimu; Shedrack Reuben Kitimu; Julian eTaylor; Timothy J March; Fred eTairo; Mike J Wilkinson; Carlos Marcelino Rodriguez Lopez

    2015-01-01

    There is great interest in the phenotypic, genetic and epigenetic changes associated with plant in vitro culture known as somaclonal variation. In vitro propagation systems that are based on the use of microcuttings or meristem cultures are considered analogous to clonal cuttings and so widely viewed to be largely free from such somaclonal effects. In this study, we surveyed for epigenetic changes during propagation by meristem culture and by field cuttings in five cassava (Manihot esculenta...

  16. Induced mutations in ornamental plants by 'in vitro' irradiation of Petunia hybrida meristems

    International Nuclear Information System (INIS)

    Gonzalez-Jimenez, J.

    1993-01-01

    In recent decades it has been observed that for the induction of mutation in ornamental plants we can obtain better results when the plants are irradiated in vegetative state and even better 'in vitro' that when its are irradiated 'in vivo'. In this work the possibilities are showed to avoid the best use of a new biotechnology: the gamma irradiations on the meristem 'in vitro'. A tissue culture method was described for the best vegetative propagation of Petunia hybrid hort through morphogenesis induction of meristem. These were planted in the Murashige and Skoog's basic medium added with BAP and ANA. The pH was adjusted to 6.5 prior autoclaving at 121 Centigrade degree and 1.1 Kg/ cm 2 for 15 minutes. Latter the meristem of plantules in immature and mature physiology stated were irradiated with gamma ray doses ranging from 1.0 at 10.0 Gy. The meristem were then subcultived aseptically with the following results: 1) The immature stage was higher radio sensibilities. 2) The LD 50 for the matured plants was to ranged from 1.0 at 9.0 Gy. and immature 1.0 at 8.0 Gy. 3) The better doses was at 7.5 Gy. 4) The meristem gamma irradiation at 7.5 Gy. showed in the first culture: the adventitious bud induced and the multi meristem formation. 5) In the second cultured the results reveals the 'variegadas' plants formations and the new purples flowers. (Author)

  17. An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

    Directory of Open Access Journals (Sweden)

    Eddy Risseeuw

    Full Text Available Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

  18. An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

    Science.gov (United States)

    Risseeuw, Eddy; Venglat, Prakash; Xiang, Daoquan; Komendant, Kristina; Daskalchuk, Tim; Babic, Vivijan; Crosby, William; Datla, Raju

    2013-01-01

    Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

  19. Cytotoxicity of Cheese and Cheddar Cheese food flavorings on Allim cepa L root meristems

    Directory of Open Access Journals (Sweden)

    A. G. Moura

    Full Text Available Abstract Despite their great importance for the food industry, flavorings, in general, raise a number of questions regarding their cytotoxicity, mutagenicity and carcinogenicity, since, in the literature, there are few studies found evaluating the toxicity on the systemic and cellular level, of these chemical compounds. The root meristems of Allium cepa (onion are widely used for the assessment of toxicity of chemical compounds of interest. Thus, this study aimed to evaluate, in A. cepa meristematic cells, individually and in combination at the cellular level, the toxicity of synthetic Cheese and Cheddar Cheese food flavorings, identical to the natural, at doses of 1.0 and 2.0 mL, at exposure times of 24 and 48 hours. In combination we used 0.5 mL of Cheese flavor associated with 0.5 mL of Cheddar flavor; and 1.0 mL of Cheese flavor associated with 1.0 mL of Cheddar flavor, at exposure times of 24 and 48 hours. For these evaluations, we used groups of five onion bulbs, which were first embedded in distilled water and then transferred to their respective doses. The root tips were collected and fixed in acetic acid (3:1 for 24 hours. The slides were prepared by crushing and were stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and exposure time. The mitotic indices calculated and cellular aberrations observed were subjected to statistical analysis using the chi-square test (p <0.05. No chromosomal abnormalities nor those of mitotic spindle were observed for the treatments performed. The results, both individually and in combination, showed that the flavorings under study significantly reduced the cell division rate of the test system cells used. Therefore, under the conditions studied, the two flavorings were cytotoxic.

  20. 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...

  1. 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…

  2. 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…

  3. 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.…

  4. 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…

  5. Meristem micropropagation of cassava (Manihot esculenta evokes genome-wide changes in DNA methylation

    Directory of Open Access Journals (Sweden)

    Shedrack Reuben Kitimu

    2015-08-01

    Full Text Available There is great interest in the phenotypic, genetic and epigenetic changes associated with plant in vitro culture known as somaclonal variation. In vitro propagation systems that are based on the use of microcuttings or meristem cultures are considered analogous to clonal cuttings and so widely viewed to be largely free from such somaclonal effects. In this study, we surveyed for epigenetic changes during propagation by meristem culture and by field cuttings in five cassava (Manihot esculenta cultivars. Principal Co-ordinate Analysis of profiles generated by Methylation Sensitive Amplified Polymorphism (MSAP revealed clear divergence between samples taken from field-grown cuttings and those recovered from meristem culture. There was also good separation between the tissues of field samples but this effect was less distinct among the meristem culture materials. Application of methylation-sensitive Genotype By Sequencing (msGBS identified 105 candidate epimarks that distinguish between field cutting and meristem culture samples. Cross referencing the sequences of these epimarks to the draft cassava genome revealed 102 sites associated with genes whose homologues have been implicated in a range of fundamental biological processes including cell differentiation, development, sugar metabolism, DNA methylation, stress response, photosynthesis, and transposon activation. We explore the relevance of these findings for the selection of micropropagation systems for use on this and other crops.

  6. Meristem micropropagation of cassava (Manihot esculenta) evokes genome-wide changes in DNA methylation.

    Science.gov (United States)

    Kitimu, Shedrack R; Taylor, Julian; March, Timothy J; Tairo, Fred; Wilkinson, Mike J; Rodríguez López, Carlos M

    2015-01-01

    There is great interest in the phenotypic, genetic and epigenetic changes associated with plant in vitro culture known as somaclonal variation. In vitro propagation systems that are based on the use of microcuttings or meristem cultures are considered analogous to clonal cuttings and so widely viewed to be largely free from such somaclonal effects. In this study, we surveyed for epigenetic changes during propagation by meristem culture and by field cuttings in five cassava (Manihot esculenta) cultivars. Principal Co-ordinate Analysis of profiles generated by methylation-sensitive amplified polymorphism revealed clear divergence between samples taken from field-grown cuttings and those recovered from meristem culture. There was also good separation between the tissues of field samples but this effect was less distinct among the meristem culture materials. Application of methylation-sensitive Genotype by sequencing identified 105 candidate epimarks that distinguish between field cutting and meristem culture samples. Cross referencing the sequences of these epimarks to the draft cassava genome revealed 102 sites associated with genes whose homologs have been implicated in a range of fundamental biological processes including cell differentiation, development, sugar metabolism, DNA methylation, stress response, photosynthesis, and transposon activation. We explore the relevance of these findings for the selection of micropropagation systems for use on this and other crops.

  7. 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

  8. 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.…

  9. 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...

  10. Gene expression polymorphisms and ESTs associated with gravitropic response of subterranean branch meristems and growth habit in Leymus wildryes

    Science.gov (United States)

    Parminder Kaur; Ivan W. Mott; Steven R. Larson; B. Shaun Bushman; Alvaro G. Hernandez; W. Ryan Kim; Lei Liu; Mark A. Mikel

    2008-01-01

    Negatively orthogeotropic (NOGT) tiller and diageotropic (DGT) rhizome meristems develop from the same type of lateral axillary meristems and phytomer structure. Although subterranean NOGT and DGT buds appear similar, they display different responses to gravity and perhaps other cues governing branch angle and overall growth habit (GH). Leymus wildryes show remarkable...

  11. 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.

  12. 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.

  13. 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.

  14. Infection cycle of Artichoke Italian latent virus in tobacco plants: meristem invasion and recovery from disease symptoms.

    Directory of Open Access Journals (Sweden)

    Elisa Santovito

    Full Text Available Nepoviral infections induce recovery in fully expanded leaves but persist in shoot apical meristem (SAM by a largely unknown mechanism. The dynamics of infection of a grapevine isolate of Artichoke Italian latent virus (AILV-V, genus Nepovirus in tobacco plants, including colonization of SAM, symptom induction and subsequent recovery of mature leaves from symptoms, were characterized. AILV-V moved from the inoculated leaves systemically and invaded SAM in 7 days post-inoculation (dpi, remaining detectable in SAM at least up to 40 dpi. The new top leaves recovered from viral symptoms earliest at 21 dpi. Accumulation of viral RNA to a threshold level was required to trigger the overexpression of RDR6 and DCL4. Consequently, accumulation of viral RNA decreased in the systemically infected leaves, reaching the lowest concentration in the 3rd and 4th leaves at 23 dpi, which was concomitant with recovery of the younger, upper leaves from disease symptoms. No evidence of virus replication was found in the recovered leaves, but they contained infectious virus particles and were protected against re-inoculation with AILV-V. In this study we also showed that AILV-V did not suppress initiation or maintenance of RNA silencing in transgenic plants, but was able to interfere with the cell-to-cell movement of the RNA silencing signal. Our results suggest that AILV-V entrance in SAM and activation of RNA silencing may be distinct processes since the latter is triggered in fully expanded leaves by the accumulation of viral RNA above a threshold level rather than by virus entrance in SAM.

  15. Alteration of plant meristem function by manipulation of the Retinoblastoma-like plant RRB gene

    Science.gov (United States)

    Durfee, Tim [Madison, WI; Feiler, Heidi [Albany, CA; Gruissem, Wilhelm [Forch, CH; Jenkins, Susan [Martinez, CA; Roe, Judith [Manhattan, KS; Zambryski, Patricia [Berkeley, CA

    2007-01-16

    This invention provides methods and compositions for altering the growth, organization, and differentiation of plant tissues. The invention is based on the discovery that, in plants, genetically altering the levels of Retinoblastoma-related gene (RRB) activity produces dramatic effects on the growth, proliferation, organization, and differentiation of plant meristem.

  16. CYCP2;1 integrates genetic and nutritional information to promote meristem cell division in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Peng, L.; Skylar, A.; Chang, P.L.; Bišová, Kateřina; Wu, X.

    2014-01-01

    Roč. 393, č. 2 (2014), s. 160-170 ISSN 0012-1606 R&D Projects: GA AV ČR M200201205 Grant - others:NSF(US) MCB-1122213 Institutional support: RVO:61388971 Keywords : cell cycle * arabidopsis * meristem Subject RIV: EE - Microbiology, Virology Impact factor: 3.547, year: 2014

  17. [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.

  18. Localization of cells containing sedimented amyloplasts in the shoots of normal and lazy rice seedlings.

    Science.gov (United States)

    Abe, K; Takahashi, H; Suge, H

    1994-12-01

    We have examined the localization of the cells containing sedimented amyloplasts (putative statocytes) and its relation to the graviresponding sites in the shoots of normal and lazy rice seedlings. All graviresponsive organs of the shoots of normal rice seedlings, the mesocotyl, the coleoptile and the leaf-sheath base, were found to possess the statocytes. This is the first indication that mesocotyl senses gravity by its own cells in inducing gravitropic bending in rice seedlings. In lazy-Kamenoo, although the shoots lost their gravitropic response with the advance of age, sedimentation of amyloplasts itself might not be attributable to the agravitropic growth of the shoots, because, including those of the leaf-sheath bases that had lost their response to gravity, sedimented amyloplasts appeared to be identical to those of normal Kamenoo and of younger seedlings of lazy-Kamenoo whose gravitropism is still apparent.

  19. Salicylic acid antagonizes abscisic acid inhibition of shoot growth and cell cycle progression in rice

    Science.gov (United States)

    Meguro, Ayano; Sato, Yutaka

    2014-04-01

    We analysed effects of abscisic acid (ABA, a negative regulatory hormone), alone and in combination with positive or neutral hormones, including salicylic acid (SA), on rice growth and expression of cell cycle-related genes. ABA significantly inhibited shoot growth and induced expression of OsKRP4, OsKRP5, and OsKRP6. A yeast two-hybrid assay showed that OsKRP4, OsKRP5, and OsKRP6 interacted with OsCDKA;1 and/or OsCDKA;2. When SA was simultaneously supplied with ABA, the antagonistic effect of SA completely blocked ABA inhibition. SA also blocked ABA inhibition of DNA replication and thymidine incorporation in the shoot apical meristem. These results suggest that ABA arrests cell cycle progression by inducing expression of OsKRP4, OsKRP5, and OsKRP6, which inhibit the G1/S transition, and that SA antagonizes ABA by blocking expression of OsKRP genes.

  20. Superfluid helium on on-orbit transfer (SHOOT) flight experiment

    International Nuclear Information System (INIS)

    DiPirro, M.J.; Kittel, P.

    1988-01-01

    The SHOOT flight demonstration is being undertaken to verify component and system level technology necessary to resupply large superfluid helium dewars in space. The baseline configuration uses two identical 210 liter dewars connected by a transfer line which contains a quick disconnect coupling. The helium is transferred back and forth between the dewars under various conditions of flow rate, parasitic heat load, and temperature. An astronaut Extra-Vehicular Activity is also planned to manually mate and demate the coupling. The components necessary for the flight and currently being developed are described

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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…

  6. 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 ...

  7. 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.

  8. Improved and Reproducible Flow Cytometry Methodology for Nuclei Isolation from Single Root Meristem

    Directory of Open Access Journals (Sweden)

    Thaís Cristina Ribeiro Silva

    2010-01-01

    Full Text Available Root meristems have increasingly been target of cell cycle studies by flow cytometric DNA content quantification. Moreover, roots can be an alternative source of nuclear suspension when leaves become unfeasible and for chromosome analysis and sorting. In the present paper, a protocol for intact nuclei isolation from a single root meristem was developed. This proceeding was based on excision of the meristematic region using a prototypical slide, followed by short enzymatic digestion and mechanical isolation of nuclei during homogenization with a hand mixer. Such parameters were optimized for reaching better results. Satisfactory nuclei amounts were extracted and analyzed by flow cytometry, producing histograms with reduced background noise and CVs between 3.2 and 4.1%. This improved and reproducible technique was shown to be rapid, inexpensive, and simple for nuclear extraction from a single root tip, and can be adapted for other plants and purposes.

  9. SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation.

    Science.gov (United States)

    Li, Jintao; Zhao, Yu; Chu, Huangwei; Wang, Likai; Fu, Yanru; Liu, Ping; Upadhyaya, Narayana; Chen, Chunli; Mou, Tongmin; Feng, Yuqi; Kumar, Prakash; Xu, Jian

    2015-08-01

    Little is known about how the size of meristem cells is regulated and whether it participates in the control of meristem size in plants. Here, we report our findings on shoebox (shb), a mild gibberellin (GA) deficient rice mutant that has a short root meristem size. Quantitative analysis of cortical cell length and number indicates that shb has shorter, rather than fewer, cells in the root meristem until around the fifth day after sowing, from which the number of cortical cells is also reduced. These defects can be either corrected by exogenous application of bioactive GA or induced in wild-type roots by a dose-dependent inhibitory effect of paclobutrazol on GA biosynthesis, suggesting that GA deficiency is the primary cause of shb mutant phenotypes. SHB encodes an AP2/ERF transcription factor that directly activates transcription of the GA biosynthesis gene KS1. Thus, root meristem size in rice is modulated by SHB-mediated GA biosynthesis that regulates the elongation and proliferation of meristem cells in a developmental stage-specific manner.

  10. SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation.

    Directory of Open Access Journals (Sweden)

    Jintao Li

    2015-08-01

    Full Text Available Little is known about how the size of meristem cells is regulated and whether it participates in the control of meristem size in plants. Here, we report our findings on shoebox (shb, a mild gibberellin (GA deficient rice mutant that has a short root meristem size. Quantitative analysis of cortical cell length and number indicates that shb has shorter, rather than fewer, cells in the root meristem until around the fifth day after sowing, from which the number of cortical cells is also reduced. These defects can be either corrected by exogenous application of bioactive GA or induced in wild-type roots by a dose-dependent inhibitory effect of paclobutrazol on GA biosynthesis, suggesting that GA deficiency is the primary cause of shb mutant phenotypes. SHB encodes an AP2/ERF transcription factor that directly activates transcription of the GA biosynthesis gene KS1. Thus, root meristem size in rice is modulated by SHB-mediated GA biosynthesis that regulates the elongation and proliferation of meristem cells in a developmental stage-specific manner.

  11. Autoradiographic study of gamma-ray induced unscheduled DNA synthesis in bean root meristem cells

    International Nuclear Information System (INIS)

    Liu Zhenshen; Qiu Quanfa; Chen Dongli

    1989-01-01

    The gamma-ray induced unscheduled DNA synthesis in root meristem cells of Vica faba was studied autoradiographically by calculating the number of cells with different 3H-thymidine labelling degree. It was found that the level of unscheduled synthesis in cells with intermediate dose (500 R) irradiation was higher than that in cells with lower dose (250 R) irradiation; however, higher dose (1000 R) irradiation would inhibit the reparative replication

  12. Agave tequilana MADS genes show novel expression patterns in meristems, developing bulbils and floral organs.

    Science.gov (United States)

    Delgado Sandoval, Silvia del Carmen; Abraham Juárez, María Jazmín; Simpson, June

    2012-03-01

    Agave tequilana is a monocarpic perennial species that flowers after 5-8 years of vegetative growth signaling the end of the plant's life cycle. When fertilization is unsuccessful, vegetative bulbils are induced on the umbels of the inflorescence near the bracteoles from newly formed meristems. Although the regulation of inflorescence and flower development has been described in detail for monocarpic annuals and polycarpic species, little is known at the molecular level for these processes in monocarpic perennials, and few studies have been carried out on bulbils. Histological samples revealed the early induction of umbel meristems soon after the initiation of the vegetative to inflorescence transition in A. tequilana. To identify candidate genes involved in the regulation of floral induction, a search for MADS-box transcription factor ESTs was conducted using an A. tequilana transcriptome database. Seven different MIKC MADS genes classified into 6 different types were identified based on previously characterized A. thaliana and O. sativa MADS genes and sequences from non-grass monocotyledons. Quantitative real-time PCR analysis of the seven candidate MADS genes in vegetative, inflorescence, bulbil and floral tissues uncovered novel patterns of expression for some of the genes in comparison with orthologous genes characterized in other species. In situ hybridization studies using two different genes showed expression in specific tissues of vegetative meristems and floral buds. Distinct MADS gene regulatory patterns in A. tequilana may be related to the specific reproductive strategies employed by this species.

  13. Ethylene Inhibits Cell Proliferation of the Arabidopsis Root Meristem1[OPEN

    Science.gov (United States)

    Street, Ian H.; Aman, Sitwat; Zubo, Yan; Ramzan, Aleena; Wang, Xiaomin; Shakeel, Samina N.; Kieber, Joseph J.; Schaller, G. Eric

    2015-01-01

    The root system of plants plays a critical role in plant growth and survival, with root growth being dependent on both cell proliferation and cell elongation. Multiple phytohormones interact to control root growth, including ethylene, which is primarily known for its role in controlling root cell elongation. We find that ethylene also negatively regulates cell proliferation at the root meristem of Arabidopsis (Arabidopsis thaliana). Genetic analysis indicates that the inhibition of cell proliferation involves two pathways operating downstream of the ethylene receptors. The major pathway is the canonical ethylene signal transduction pathway that incorporates CONSTITUTIVE TRIPLE RESPONSE1, ETHYLENE INSENSITIVE2, and the ETHYLENE INSENSITIVE3 family of transcription factors. The secondary pathway is a phosphorelay based on genetic analysis of receptor histidine kinase activity and mutants involving the type B response regulators. Analysis of ethylene-dependent gene expression and genetic analysis supports SHORT HYPOCOTYL2, a repressor of auxin signaling, as one mediator of the ethylene response and furthermore, indicates that SHORT HYPOCOTYL2 is a point of convergence for both ethylene and cytokinin in negatively regulating cell proliferation. Additional analysis indicates that ethylene signaling contributes but is not required for cytokinin to inhibit activity of the root meristem. These results identify key elements, along with points of cross talk with cytokinin and auxin, by which ethylene negatively regulates cell proliferation at the root apical meristem. PMID:26149574

  14. Hard Identity and Soft Identity

    Directory of Open Access Journals (Sweden)

    Hassan Rachik

    2006-04-01

    Full Text Available Often collective identities are classified depending on their contents and rarely depending on their forms. Differentiation between soft identity and hard identity is applied to diverse collective identities: religious, political, national, tribal ones, etc. This classification is made following the principal dimensions of collective identities: type of classification (univocal and exclusive or relative and contextual, the absence or presence of conflictsof loyalty, selective or totalitarian, objective or subjective conception, among others. The different characteristics analysed contribute to outlining an increasingly frequent type of identity: the authoritarian identity.

  15. The Growth and Cultivation of Meristem From Shallot (Allium ascalonicum L. cv. Katumi by In Vitro

    Directory of Open Access Journals (Sweden)

    Lamro Purba

    2017-12-01

    Full Text Available This study aimed for knowing and obtaining the best concentration of kinetin and NAA interaction effects in influencing the shoot induction, knowing how the plant growth regulators in induction mediastill affect the shoot additionin the MS0media and also knowing the largest number of roots in rooting media for shallot by in vitro. The experiment was conducted at Laboratory of Tissue Culture Seed Technology, Faculty of Agriculture, Padjadjaran University, during January 2011 until May 2011. This experiment divided in 3 stages, namely shoot induction stage, shoot subculture to MS0 media stage and shoot subculture to rooting media stage. Experimental method used in the shoot induction stage was factorial Completely Randomized Design with three replications. The first factor was the kinetin with four levels,0, 1, 2, and 3 mg L-1. The second factor was the NAA with three levels, as 0, 0.01, and 0.1 mg L-1. Basic media used for each treatment was MS. The experiment result showed there was an interaction between kinetin and NAA on shoot induction stagewith the plantlet height, leaf number, and shoot addition. The best result for leaf number was gained from interaction with 2 mg L-1 kinetin without NAA,while the treatment of 2 mg L-1 kinetin with 0.01 mg L-1 NAA gave a better interaction for theshoot addition variable.

  16. 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

  17. 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...

  18. 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.

  19. 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.

  20. Leadership identities

    DEFF Research Database (Denmark)

    Holmgreen, Lise-Lotte

    2018-01-01

    Questioning the assumption that identities can be controlled through a shared organisational culture, the article explores the inculcation of a discourse of diversity into leadership identities in a Danish bank and building society. Thus, it intends to demonstrate that, on the one hand, discourse...... plays a significant role in identity construction and, on the other, that leaders’ constructions may have many sources of inspiration within and outside the organisation, emphasising that identity construction is a complex process in which organisational efforts to promote a common leadership identity...... to construct their leadership identities. While the respondents present comparable identities to the interviewer, the analysis reveals that the they draw on different discourses and employ a number of different discursive means to present this identity. This, the article argues, may be the result of a number...

  1. Ternutator identities

    International Nuclear Information System (INIS)

    Devchand, Chandrashekar; Fairlie, David; Nuyts, Jean; Weingart, Gregor

    2009-01-01

    The ternary commutator or ternutator, defined as the alternating sum of the product of three operators, has recently drawn much attention as an interesting structure generalizing the commutator. The ternutator satisfies cubic identities analogous to the quadratic Jacobi identity for the commutator. We present various forms of these identities and discuss the possibility of using them to define ternary algebras.

  2. 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.

  3. Reactivation of meristem activity and sprout growth in potato tubers require both cytokinin and gibberellin.

    Science.gov (United States)

    Hartmann, Anja; Senning, Melanie; Hedden, Peter; Sonnewald, Uwe; Sonnewald, Sophia

    2011-02-01

    Reactivation of dormant meristems is of central importance for plant fitness and survival. Due to their large meristem size, potato (Solanum tuberosum) tubers serve as a model system to study the underlying molecular processes. The phytohormones cytokinins (CK) and gibberellins (GA) play important roles in releasing potato tuber dormancy and promoting sprouting, but their mode of action in these processes is still obscure. Here, we established an in vitro assay using excised tuber buds to study the dormancy-releasing capacity of GA and CK and show that application of gibberellic acid (GA(3)) is sufficient to induce sprouting. In contrast, treatment with 6-benzylaminopurine induced bud break but did not support further sprout growth unless GA(3) was administered additionally. Transgenic potato plants expressing Arabidopsis (Arabidopsis thaliana) GA 20-oxidase or GA 2-oxidase to modify endogenous GA levels showed the expected phenotypical changes as well as slight effects on tuber sprouting. The isopentenyltransferase (IPT) from Agrobacterium tumefaciens and the Arabidopsis cytokinin oxidase/dehydrogenase1 (CKX) were exploited to modify the amounts of CK in transgenic potato plants. IPT expression promoted earlier sprouting in vitro. Strikingly, CKX-expressing tubers exhibited a prolonged dormancy period and did not respond to GA(3). This supports an essential role of CK in terminating tuber dormancy and indicates that GA is not sufficient to break dormancy in the absence of CK. GA(3)-treated wild-type and CKX-expressing tuber buds were subjected to a transcriptome analysis that revealed transcriptional changes in several functional groups, including cell wall metabolism, cell cycle, and auxin and ethylene signaling, denoting events associated with the reactivation of dormant meristems.

  4. Bringing sexy back: reclaiming the body aesthetic via self-shooting

    DEFF Research Database (Denmark)

    Tiidenberg, Katrin

    2014-01-01

    ’s ‘technologies of the self’ to analyze self-shooting (taking photos of one-self). Constricting societal norms of sexuality, body shape and body practices influence how my participants (N=20, 10 female, 9 male, 1 transgender, ages 21 - 51, average age 34) live their embodied and sexual lives. Through self-shooting...... and by negotiating the community specific issues of control, power and the gaze, they are able to construct a new, empowered, embodied identity for themselves. I look at self-shooting and selfie-blogging as a practice of reclaiming control over one’s embodied self AND over the body-aesthetic, thus appropriating what...... is and is not ‘sexy’. The NSFW self-shooting community offers a safe space otherwise so hard to find within the body/sexuality-normative mainstream culture. This makes self-shooting a collective therapeutic activity. In their self-images participants construct themselves as ‘beautiful’, ‘sexy’, ‘devious’, ‘more than...

  5. Grief and Solidarity Reactions 1 Week After an On-Campus Shooting.

    Science.gov (United States)

    Wayment, Heidi A; Silver, Roxane Cohen

    2018-03-01

    The impact of interpersonal violence extends beyond the victims and perpetrator(s). The purpose of this research was threefold: (a) to identify whether college students' very early reactions to an on-campus shooting were associated with well-known predictors of distress, (b) to examine whether grief and distress reactions were distinguishable in the early days following a shooting, and (c) to investigate whether a compassionate self-identity was uniquely associated with grief but not distress. Beginning just 3 days after an early morning shooting that killed one student and injured three others, university students ( N = 408) completed an online questionnaire. Grief, but not distress, was associated with a sense of solidarity with other students and a compassionate self-identity. General distress was associated with prior mental health difficulties and exposure to the shooting. Acute stress was positively associated with being female, having prior mental health difficulties, media exposure, perceived similarity to victims, less victim blame, social support, and social strain. Results suggest that grief reactions that arise in the early days following a collective loss may serve as important psychosocial resources in coping with interpersonal violence.

  6. Optimization of a protocol for direct organogenesis of red clover (Trifolium pratense L. meristems for breeding purposes

    Directory of Open Access Journals (Sweden)

    JUAN C CARRILLO

    2004-01-01

    Full Text Available A series of experiments were carried out in order to optimize a protocol for the direct organogenesis of Chilean red clover germplasm. A range of cultivars were used to analyze the effect of explant source (crown or stem meristems of vegetative plants, culture media and plant growth regulators. Our findings showed that stem meristems were easier to obtain, presented lower levels of contamination and a better development than crown meristems. The L2 medium showed better results than B5 and MS media for the cultivars and experimental lines studied. L2 medium supplemented with 0.003 mg/l of 4-amino-3,5,6-trichloropicolinic acid and 1.0 mg/l of 6-benzylaminopurine gave consistently better results and will be applied in our breeding program to propagate, maintain and eliminate viruses from elite red clover clones.

  7. 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

  8. Plant-specific histone deacetylases HDT1/2 regulate GIBBERELLIN 2-OXIDASE2 expression to control arabidopsis root meristem cell number

    NARCIS (Netherlands)

    Li, Huchen; Torres-Garcia, Jesus; Latrasse, David; Benhamed, Moussa; Schilderink, Stefan; Zhou, Wenkun; Kulikova, Olga; Hirt, Heribert; Bisseling, Ton

    2017-01-01

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription factors and chromatin-remodeling factors have been

  9. 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.

  10. 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

  11. Propagación in vitro de Carica papaya var. PTM-331 a partir de meristemos apicales In vitro propagation of Carica papaya var. PTM-331 from apical meristem

    Directory of Open Access Journals (Sweden)

    Reynaldo Solis L.

    2012-02-01

    Full Text Available El trabajo consistió en desarrollar un protocolo de propagación in vitro de la variedad de papaya PTM-331 a partir de meristemos apicales, con la finalidad de obtener plántulas vigorosas y libres de enfermedades, empleando la técnica del cultivo de tejidos. Las yemas apicales empleadas fueron obtenidas de plantas cultivadas en invernadero, los cuales fueron usados como explantes para la extracción de meristemos. La mejor diferenciación de meristemos se logró en el medio basal MS suplementado con 0,5 mg.L-1 de BAP, 0,5 mg.L-1 de AIA y 10 mg.L-1 de adenina. La mejor multiplicación se logró con el medio MS suplementado con 0,5 mg.L-1 de BAP, 0,5 mg.L-1 de AIA y 0,3 mg.L-1 de AG3, con un coeficiente de multiplicación de 3,42; mientras que el mejor medio para el enraizamiento fue la combinación del medio MS, 3 mg.L-1 de AIB y 5 mg.L-1 de adenina, donde se obtuvo 83,33% de plantas enraizadas.An in vitro protocol was develop to propagate variety of papaya PTM-331 from apical meristems, with the objective of obtaining vigorous and disease-free seedlings, using tissue culture techniques. Apical buds were obtained from seedlings cultivated in greenhouse and used as explants for meristem dissection. Meristems were cultured on MS basal medium supplemented with 0,5 mg.L-1 of BAP, 0,5 mg.L-1 of AIA and 10 mg.L-1 of adenine for their differentiation. The best multiplication of explants was achieved with the combination of MS medium supplemented with 0,5 mg.L-1 of BAP, 0,5 mg.L-1 of AIA and 0,3 mg.L-1 of AG3, where largest seedlings, with more shoots were obtained. The best medium for rooting was the combination of MS, 3 mg.L-1 of AIB and 5 mg.L-1 of adenine, where 83,33% of rooted plants were obtained.

  12. Synchronisms and correlations of spring phenology between apical and lateral meristems in two boreal conifers.

    Science.gov (United States)

    Antonucci, Serena; Rossi, Sergio; Deslauriers, Annie; Lombardi, Fabio; Marchetti, Marco; Tognetti, Roberto

    2015-10-01

    Phenological synchronisms between apical and lateral meristems could clarify some aspects related to the physiological relationships among the different organs of trees. This study correlated the phenological phases of bud development and xylem differentiation during spring 2010-14 in balsam fir (Abies balsamea Mill.) and black spruce [(Picea mariana Mill. (BSP)] of the Monts-Valin National Park (Quebec, Canada) by testing the hypothesis that bud development occurs after the reactivation of xylem growth. From May to September, we conducted weekly monitoring of xylem differentiation using microcores and bud development with direct observations on terminal branches. Synchronism between the beginning of bud development and xylem differentiation was found in both species with significant correlations between the phases of bud and xylem phenology. Degree-day sum was more appropriate in assessing the date of bud growth resumption, while thermal thresholds were more suitable for cambium phenology. Our results provide new knowledge on the dynamics of spring phenology and novel information on the synchronisms between two meristems in coniferous trees. The study demonstrates the importance of precisely defining the phases of bud development in order to correctly analyse the relationships with xylem phenology. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Optimized Whole-Mount In Situ Immunolocalization for Arabidopsis thaliana Root Meristems and Lateral Root Primordia.

    Science.gov (United States)

    Karampelias, Michael; Tejos, Ricardo; Friml, Jiří; Vanneste, Steffen

    2018-01-01

    Immunolocalization is a valuable tool for cell biology research that allows to rapidly determine the localization and expression levels of endogenous proteins. In plants, whole-mount in situ immunolocalization remains a challenging method, especially in tissues protected by waxy layers and complex cell wall carbohydrates. Here, we present a robust method for whole-mount in situ immunolocalization in primary root meristems and lateral root primordia in Arabidopsis thaliana. For good epitope preservation, fixation is done in an alkaline paraformaldehyde/glutaraldehyde mixture. This fixative is suitable for detecting a wide range of proteins, including integral transmembrane proteins and proteins peripherally attached to the plasma membrane. From initiation until emergence from the primary root, lateral root primordia are surrounded by several layers of differentiated tissues with a complex cell wall composition that interferes with the efficient penetration of all buffers. Therefore, immunolocalization in early lateral root primordia requires a modified method, including a strong solvent treatment for removal of hydrophobic barriers and a specific cocktail of cell wall-degrading enzymes. The presented method allows for easy, reliable, and high-quality in situ detection of the subcellular localization of endogenous proteins in primary and lateral root meristems without the need of time-consuming crosses or making translational fusions to fluorescent proteins.

  14. Redox Changes During the Cell Cycle in the Embryonic Root Meristem of Arabidopsis thaliana.

    Science.gov (United States)

    de Simone, Ambra; Hubbard, Rachel; de la Torre, Natanael Viñegra; Velappan, Yazhini; Wilson, Michael; Considine, Michael J; Soppe, Wim J J; Foyer, Christine H

    2017-12-20

    The aim of this study was to characterize redox changes in the nuclei and cytosol occurring during the mitotic cell cycle in the embryonic roots of germinating Arabidopsis seedlings, and to determine how redox cycling was modified in mutants with a decreased capacity for ascorbate synthesis. Using an in vivo reduction-oxidation (redox) reporter (roGFP2), we show that transient oxidation of the cytosol and the nuclei occurred at G1 in the synchronized dividing cells of the Arabidopsis root apical meristem, with reduction at G2 and mitosis. This redox cycle was absent from low ascorbate mutants in which nuclei were significantly more oxidized than controls. The cell cycle-dependent increase in nuclear size was impaired in the ascorbate-deficient mutants, which had fewer cells per unit area in the root proliferation zone. The transcript profile of the dry seeds and size of the imbibed seeds was strongly influenced by low ascorbate but germination, dormancy release and seed aging characteristics were unaffected. These data demonstrate the presence of a redox cycle within the plant cell cycle and that the redox state of the nuclei is an important factor in cell cycle progression. Controlled oxidation is a key feature of the early stages of the plant cell cycle. However, sustained mild oxidation restricts nuclear functions and impairs progression through the cell cycle leading to fewer cells in the root apical meristem. Antioxid. Redox Signal. 27, 1505-1519.

  15. Meristem Plant Cells as a Sustainable Source of Redox Actives for Skin Rejuvenation

    Science.gov (United States)

    Korkina, Liudmila G.; Mayer, Wolfgang; de Luca, Chiara

    2017-01-01

    Recently, aggressive advertisement claimed a “magic role” for plant stem cells in human skin rejuvenation. This review aims to shed light on the scientific background suggesting feasibility of using plant cells as a basis of anti-age cosmetics. When meristem cell cultures obtained from medicinal plants are exposed to appropriate elicitors/stressors (ultraviolet, ultrasound ultraviolet (UV), ultrasonic waves, microbial/insect metabolites, heavy metals, organic toxins, nutrient deprivation, etc.), a protective/adaptive response initiates the biosynthesis of secondary metabolites. Highly bioavailable and biocompatible to human cells, low-molecular weight plant secondary metabolites share structural/functional similarities with human non-protein regulatory hormones, neurotransmitters, pigments, polyamines, amino-/fatty acids. Their redox-regulated biosynthesis triggers in turn plant cell antioxidant and detoxification molecular mechanisms resembling human cell pathways. Easily isolated in relatively large quantities from contaminant-free cell cultures, plant metabolites target skin ageing mechanisms, above all redox imbalance. Perfect modulators of cutaneous oxidative state via direct/indirect antioxidant action, free radical scavenging, UV protection, and transition-metal chelation, they are ideal candidates to restore photochemical/redox/immune/metabolic barriers, gradually deteriorating in the ageing skin. The industrial production of plant meristem cell metabolites is toxicologically and ecologically sustainable for fully “biological” anti-age cosmetics. PMID:28498360

  16. Medical Identity

    DEFF Research Database (Denmark)

    Musaeus, Peter

    2015-01-01

    Purpose: To examine philosophical stances underpinning medical identity and assess the conceptual relationship between physician, medical practice and culture. Argument: Medical identity is about the ideals and moral positions that physicians take when justifying themselves. Medical identity...... hedonistic versus sentimentalist approaches to medical identity. The sociocultural philosophical analysis of medical identity can shed light on what it means conceptually for a physician to harbor beliefs associated with him/her being taken to be an autonomous professional. It is important because it touches...... on the meaning of being a compassionate, good and skilled physician, making its relevance to person-centered medicine self-evident. Conclusion: Medical identity should be analyzed with reference to literature, philosophy and medical practice in order for the physician to exercise a reflective position...

  17. Identity paradoxes

    Directory of Open Access Journals (Sweden)

    Đurić Jelena

    2010-01-01

    Full Text Available The article considers paradoxical nature of identity that emerges from: 1 the very concept of identity whose abstract generality unites various and even opposite features; 2 the processual nature of reality that is easier to express in the poetical metaphors or abstract principles than in unambiguous conceptual networks; 3 the oppose relationship between being and knowledge, mind and matter, subject and object, self and personality. Entangled in the labyrinth which evade efforts to be conceptually defined, the modern thinking of identity moves towards abandoning the idea of “self” on behalf of the “ego” and towards the misapprehension of identity as being identical. This corresponds to the “time of the lost spirit” stretched between the simultaneous need to find an identity and to give it up.

  18. 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.

  19. 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.

  20. Identity Management

    Data.gov (United States)

    Social Security Administration — Provides information for identity management services on the creation, modification and eventual deletion of accounts and entitlements based on user relationships on...

  1. Identity Assemblages

    DEFF Research Database (Denmark)

    Horn, Line Helverskov

    The study aims at exploring how identity is enacted within the context of a two-year programme in Service, Hospitality, and Tourism Management (SHTM). This research thus investigates how students and educators go about their daily lives in different educational contexts both on and off campus...... as a contribution to the body of literature of ANT-based studies. Second, it contributes to existing identity theories by exemplifying a socio-material approach to identity issues. Third, the study enables reflections upon how educational institutions as fundamentally identity-producing organisations acknowledge...

  2. Civil Identity

    DEFF Research Database (Denmark)

    Petersen, Lars Axel

    In this paper I will go through a catalogue of examples of contexts in which the term civil identity is currently used, ranging from the formal and technical process of linking a set of administrative and other events to an individual biological person by means of identity cards, fingerprints, iris...... of Israel to Luce Irigaray's Feminist agenda of elaborating gender specific civil identities. My intention is to investigate whether these different employments of 'civil identity' point towards a common, and fairly well defined object field asking questions of contemporary relevance to the philosophy...

  3. 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...

  4. Bridging Identities

    Science.gov (United States)

    Deaux, Kay; Burke, Peter

    2010-01-01

    Sociology and psychology are no strangers in the theoretical world of self and identity. Early works by William James (1890), a psychologist, and George Herbert Mead (1934), a sociologist, are often taken as a starting point by investigators in both fields. In more recent years, with the development of a number of identity theories in both fields,…

  5. Brand Identity.

    Science.gov (United States)

    Lawlor, John

    1998-01-01

    Instead of differentiating themselves by building "brand identities," colleges and universities often focus on competing with price. As a result, fewer and fewer institutions base their identities on value, the combination of quality and price. Methods of building two concepts to influence customers' brand image and brand loyalty are…

  6. Ritual Identity

    NARCIS (Netherlands)

    van der Beek, Suzanne

    2017-01-01

    Rituals are often used as opportunities for self-reflection and identity construction. The Camino to Santiago de Compostela, which has become a singularly popular pilgrimage since the late 1980s, is an example of a ritual that is explicitly used to gain a deeper understanding of one’s identity

  7. Organizational Identity

    DEFF Research Database (Denmark)

    Hatch, Mary Jo; Schultz, Majken

    This text presents the classic works on organizational identity alongside more current thinking on the issues. Ranging from theoretical contributions to empirical studies, the readings in this volume address the key issues of organizational identity, and show how these issues have developed through...

  8. Challenging Identities

    DEFF Research Database (Denmark)

    Identity is a keyword in a number of academic fields as well as in public debate and in politics. During the last decades, references to identity have proliferated, yet there is no simple definition available that corresponds to the use of the notion in all contexts. The significance of the notion...

  9. Perceptions of Safety Among LGBTQ People Following the 2016 Pulse Nightclub Shooting.

    Science.gov (United States)

    Stults, Christopher B; Kupprat, Sandra A; Krause, Kristen D; Kapadia, Farzana; Halkitis, Perry N

    2017-09-01

    The goals of this manuscript are two-fold. First, we provide a brief reaction to this journal's "Special Section: Reflections on the Orlando Massacre on its First Anniversary." Second, we present findings from a study on perceptions of safety among LGBTQ individuals following the Pulse shooting. These issues are discussed within the historical context of hate crimes experienced by the LGBTQ population (Herek), media coverage following the shooting (Hancock & Halderman), and the immediate reaction of LGBTQ graduate students to the event (Jackson). Our study sought to examine differences in perceptions of personal and peer safety by race/ethnicity, gender identity, and sexual orientation among a large, diverse sample of LGBTQ people. Findings from our study indicate that there were differences in perceptions of personal safety by gender identity, and differences in perceptions of peer safety by gender identity and sexual orientation. These findings also suggest that subgroups of the LGBTQ community with more marginalized gender and sexual identities (e.g., female, transgender, genderqueer, bisexual, queer respondents) perceived more concerns related to safety, on average, than subgroups with relatively more privilege (e.g., gay, male). Elevated safety concern may exacerbate multiple minority stress burden, a known driver of poor health outcomes among LGBTQ people. These findings are a call to action to healthcare providers to be well informed and trained to provide the appropriate care and counseling referrals that can address the safety-related concerns of LGBTQ individuals in the aftermath of identity-related attacks.

  10. Fashioning Identity

    DEFF Research Database (Denmark)

    Mackinney-Valentin, Maria

    We dress to communicate who we are, or who we would like others to think we are, telling seductive fashion narratives through our adornment. Yet, today, fashion has been democratized through high-low collaborations, social media and real-time fashion mediation, complicating the basic dynamic...... of identity displays, and creating tension between personal statements and social performances. Fashioning Identity explores how this tension is performed through fashion production and consumption,by examining a diverse series of case studies - from ninety-year old fashion icons to the paradoxical rebellion...... by readdressing Fred Davis' seminal concept of 'identity ambivalence' in Fashion, Culture and Identity (1992), Mackinney-Valentin argues that we are in an epoch of 'status ambivalence', in which fashioning one's own identity has become increasingly complicated....

  11. 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,.

  12. 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 ...

  13. 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 ...

  14. 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…

  15. A plant U-box protein, PUB4, regulates asymmetric cell division and cell proliferation in the root meristem

    NARCIS (Netherlands)

    Kinoshita, A.; Hove, ten C.A.; Tabata, R.; Yamada, M.; Shimizu, N.; Ishida, T.; Yamaguchi, K.; Shigenobu, S.; Takebayashi, Y.; Luchies, J.; Kobayashi, M.; Kurata, T.; Wada, T.; Seo, M.; Hasebe, M.; Blilou, I.; Fukuda, H.; Scheres, B.; Heidstra, R.; Kamiya, Y.; Sawa, S.

    2015-01-01

    The root meristem (RM) is a fundamental structure that is responsible for postembryonic root growth. The RM contains the quiescent center (QC), stem cells and frequently dividing meristematic cells, in which the timing and the frequency of cell division are tightly regulated. In Arabidopsis

  16. Amyloplast displacement is necessary for gravisensing in Arabidopsis shoots as revealed by a centrifuge microscope.

    Science.gov (United States)

    Toyota, Masatsugu; Ikeda, Norifumi; Sawai-Toyota, Satoe; Kato, Takehide; Gilroy, Simon; Tasaka, Masao; Morita, Miyo Terao

    2013-11-01

    The starch-statolith hypothesis proposes that starch-filled amyloplasts act as statoliths in plant gravisensing, moving in response to the gravity vector and signaling its direction. However, recent studies suggest that amyloplasts show continuous, complex movements in Arabidopsis shoots, contradicting the idea of a so-called 'static' or 'settled' statolith. Here, we show that amyloplast movement underlies shoot gravisensing by using a custom-designed centrifuge microscope in combination with analysis of gravitropic mutants. The centrifuge microscope revealed that sedimentary movements of amyloplasts under hypergravity conditions are linearly correlated with gravitropic curvature in wild-type stems. We next analyzed the hypergravity response in the shoot gravitropism 2 (sgr2) mutant, which exhibits neither a shoot gravitropic response nor amyloplast sedimentation at 1 g. sgr2 mutants were able to sense and respond to gravity under 30 g conditions, during which the amyloplasts sedimented. These findings are consistent with amyloplast redistribution resulting from gravity-driven movements triggering shoot gravisensing. To further support this idea, we examined two additional gravitropic mutants, phosphoglucomutase (pgm) and sgr9, which show abnormal amyloplast distribution and reduced gravitropism at 1 g. We found that the correlation between hypergravity-induced amyloplast sedimentation and gravitropic curvature of these mutants was identical to that of wild-type plants. These observations suggest that Arabidopsis shoots have a gravisensing mechanism that linearly converts the number of amyloplasts that settle to the 'bottom' of the cell into gravitropic signals. Further, the restoration of the gravitropic response by hypergravity in the gravitropic mutants that we tested indicates that these lines probably have a functional gravisensing mechanism that is not triggered at 1 g. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  17. 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.

  18. 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.

  19. 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.

  20. Identity Management

    CERN Document Server

    Pace, A

    2008-01-01

    This paper introduces identity management concepts and discusses various issues associated with its implementation. It will try to highlight technical, legal, and social aspects that must been foreseen when defining the numerous processes that an identity management infrastructure must support. Grid interoperability as well as cross platform interoperability is addressed on the technical aspect, followed by a short discussion on social consequences on user’s privacy when completed traceability is enforced and some examples on how identity management has been implemented at CERN

  1. Identity management

    Energy Technology Data Exchange (ETDEWEB)

    Pace, A [CERN, Geneva (Switzerland)

    2008-07-01

    This paper introduces identity management concepts and discusses various issues associated with their implementation. It will try to highlight technical, legal, and social aspects that must been foreseen when defining the numerous processes that an identity management infrastructure must support. Grid interoperability as well as cross platform interoperability is addressed on the technical aspect, followed by a short discussion on social consequences on user's privacy when completed traceability is enforced. The paper will finally give some examples on how identity management has been implemented at CERN.

  2. Identity management

    International Nuclear Information System (INIS)

    Pace, A

    2008-01-01

    This paper introduces identity management concepts and discusses various issues associated with their implementation. It will try to highlight technical, legal, and social aspects that must been foreseen when defining the numerous processes that an identity management infrastructure must support. Grid interoperability as well as cross platform interoperability is addressed on the technical aspect, followed by a short discussion on social consequences on user's privacy when completed traceability is enforced. The paper will finally give some examples on how identity management has been implemented at CERN

  3. Electronic identity

    CERN Document Server

    de Andrade, Norberto Nuno Gomes; Argles, David

    2014-01-01

    With the increasing availability of electronic services, security and a reliable means by which identity is verified is essential.Written by Norberto Andrade the first chapter of this book provides an overview of the main legal and regulatory aspects regarding electronic identity in Europe and assesses the importance of electronic identity for administration (public), business (private) and, above all, citizens. It also highlights the role of eID as a key enabler of the economy.In the second chapter Lisha Chen-Wilson, David Argles, Michele Schiano di Zenise and Gary Wills discuss the user-cent

  4. 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.

  5. Genetic improvement of the shoot architecture and yield in soya bean plants via the manipulation of GmmiR156b.

    Science.gov (United States)

    Sun, Zhengxi; Su, Chao; Yun, Jinxia; Jiang, Qiong; Wang, Lixiang; Wang, Youning; Cao, Dong; Zhao, Fang; Zhao, Qingsong; Zhang, Mengchen; Zhou, Bin; Zhang, Lei; Kong, Fanjiang; Liu, Baohui; Tong, Yiping; Li, Xia

    2018-05-05

    The optimization of plant architecture in order to breed high-yielding soya bean cultivars is a goal of researchers. Tall plants bearing many long branches are desired, but only modest success in reaching these goals has been achieved. MicroRNA156 (miR156)-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) gene modules play pivotal roles in controlling shoot architecture and other traits in crops like rice and wheat. However, the effects of miR156-SPL modules on soya bean architecture and yield, and the molecular mechanisms underlying these effects, remain largely unknown. In this study, we achieved substantial improvements in soya bean architecture and yield by overexpressing GmmiR156b. Transgenic plants produced significantly increased numbers of long branches, nodes and pods, and they exhibited an increased 100-seed weight, resulting in a 46%-63% increase in yield per plant. Intriguingly, GmmiR156b overexpression had no significant impact on plant height in a growth room or under field conditions; however, it increased stem thickness significantly. Our data indicate that GmmiR156b modulates these traits mainly via the direct cleavage of SPL transcripts. Moreover, we found that GmSPL9d is expressed in the shoot apical meristem and axillary meristems (AMs) of soya bean, and that GmSPL9d may regulate axillary bud formation and branching by physically interacting with the homeobox gene WUSCHEL (WUS), a central regulator of AM formation. Together, our results identify GmmiR156b as a promising target for the improvement of soya bean plant architecture and yields, and they reveal a new and conserved regulatory cascade involving miR156-SPL-WUS that will help researchers decipher the genetic basis of plant architecture. © 2018 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  6. Cytogenetical and ultrastructural effects of copper on root meristem cells of Allium sativum L.

    Science.gov (United States)

    Liu, Donghua; Jiang, Wusheng; Meng, Qingmin; Zou, Jin; Gu, Jiegang; Zeng, Muai

    2009-04-01

    Different copper concentrations, as well as different exposure times, were applied to investigate both cytogenetical and ultrastructural alterations in garlic (Allium sativum L.) meristem cells. Results showed that the mitotic index decreased progressively when either copper concentration or exposure time increased. C-mitosis, anaphase bridges, chromosome stickiness and broken nuclei were observed in the copper treated root tip cells. Some particulates containing the argyrophilic NOR-associated proteins were distributed in the nucleus of the root-tip cells and the amount of this particulate material progressively increased with increasing exposure time. Finally, the nucleolar material was extruded from the nucleus into the cytoplasm. Also, increased dictyosome vesicles in number, formation of cytoplasmic vesicles containing electron dense granules, altered mitochondrial shape, disruption of nuclear membranes, condensation of chromatin material, disintegration of organelles were observed. The mechanisms of detoxification and tolerance of copper are briefly discussed.

  7. Effects of 5-fluorouracil on the mitotic activity of onion root tips apical meristem

    Directory of Open Access Journals (Sweden)

    Waldemar Lechowicz

    2015-01-01

    Full Text Available The effects of various concentrations of 5-FU on the mitotic activity of onion root tips apical meristem were investigated during 24-hour incubation in 5-FU and postincubation in water. The incubation in 5-FU caused a reversible inhibition of mitotic activity, and waves of the partially synchronised mitoses were observed during the period of postincubation. The most pronounced synchronisation of mitoses was obtained after incubation in 100 mg/l. 5-FU but the mitotic index of the resumed mitotic activity amounted to only one half of the control value. 5-FU was found to cause some cytological changes in meristematic cells such as enlargement of the nucleoli, change in the interphasic nuclei structure, appearance of subchromatid and chromatid aberrations and micronuclei. The effects of 5-FU on nucleic acids and the cell division cycle ace discussed and compared with the effects of 5-FUdR.

  8. Transcriptomic characterization of a synergistic genetic interaction during carpel margin meristem development in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    April N Wynn

    Full Text Available In flowering plants the gynoecium is the female reproductive structure. In Arabidopsis thaliana ovules initiate within the developing gynoecium from meristematic tissue located along the margins of the floral carpels. When fertilized the ovules will develop into seeds. SEUSS (SEU and AINTEGUMENTA (ANT encode transcriptional regulators that are critical for the proper formation of ovules from the carpel margin meristem (CMM. The synergistic loss of ovule initiation observed in the seu ant double mutant suggests that SEU and ANT share overlapping functions during CMM development. However the molecular mechanism underlying this synergistic interaction is unknown. Using the ATH1 transcriptomics platform we identified transcripts that were differentially expressed in seu ant double mutant relative to wild type and single mutant gynoecia. In particular we sought to identify transcripts whose expression was dependent on the coordinated activities of the SEU and ANT gene products. Our analysis identifies a diverse set of transcripts that display altered expression in the seu ant double mutant tissues. The analysis of overrepresented Gene Ontology classifications suggests a preponderance of transcriptional regulators including multiple members of the REPRODUCTIVE MERISTEMS (REM and GROWTH-REGULATING FACTOR (GRF families are mis-regulated in the seu ant gynoecia. Our in situ hybridization analyses indicate that many of these genes are preferentially expressed within the developing CMM. This study is the first step toward a detailed description of the transcriptional regulatory hierarchies that control the development of the CMM and ovule initiation. Understanding the regulatory hierarchy controlled by SEU and ANT will clarify the molecular mechanism of the functional redundancy of these two genes and illuminate the developmental and molecular events required for CMM development and ovule initiation.

  9. Spacing Identity

    DEFF Research Database (Denmark)

    Stang Våland, Marianne; Georg, Susse

    2018-01-01

    In this paper, we analyze how architectural design, and the spatial and material changes this involves, contributes to the continuous shaping of identities in an organization. Based upon a case study of organizational and architectural change in a municipal administration at a time of major public...... sector reforms, we examine how design interventions were used to (re)form work and professional relationships. The paper examines how engagements with spatial arrangements and material artifacts affected people’s sense of both occupational and organizational identity. Taking a relational approach...... to sociomateriality, the paper contributes to the further theorizing of space in organization studies by proposing the concept of spacing identity to capture the fluidity of identity performance....

  10. 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- ...

  11. 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-.

  12. 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

  13. 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 ...

  14. 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', ...

  15. 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 ...

  16. 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 ...

  17. 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.

  18. 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., ...

  19. Identity, identity politics, and neoliberalism

    Directory of Open Access Journals (Sweden)

    Wrenn Mary

    2014-01-01

    Full Text Available With the intensification of neoliberalism, it is useful to examine how some individuals might cope with the irrationality of the system. Neoliberalism cloaks the execution of the corporate agenda behind rhetorical manipulation that advocates for limited government. The corollary absence of government involvement on behalf of the citizenry writ large disarms the means of social redress for the individual. Democracy funded and fueled by corporate power thereby disenfranchises the individual, provoking some to search for empowerment through identity politics. The argument set forth suggests that individuals construct, reinforce, or escalate allegiance to identities as a coping mechanism, some of which manifest in violent identity politics.

  20. 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...

  1. 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)

  2. 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...

  3. 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...

  4. 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.

  5. 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

  6. 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.

  7. Cell radiosensitivity variation in synchronously-dividing root meristems of Pisum sativum L. and Zea mays L. during the mitotic cycle

    Energy Technology Data Exchange (ETDEWEB)

    Gudkov, I.N.; Grodzinsky, D.M. (AN Ukrainskoj SSR, Kiev. Inst. Fiziologii Rastenij)

    1982-04-01

    The cell divisions in pea and maize seedling root meristems were synchronized by treatment with 0.03 per cent hydroxyurea for 24 hours. At different times after block cessation (removing seedlings from hydroxyurea), i.e. according to certain phases and subphases of the mitotic cycle, the seedlings were treated with /sup 60/Co ..gamma..-radiation at doses from 3 to 32 Gy. Evaluation of seedling radioresistance by the survival of the main root meristem on the tenth day after irradiation led to the following sequence of cell stages in order of increasing resistance. For the pea root meristem: G/sub 2/, M, late G/sub 1/, early S, late S, middle S and early G/sub 1/. For the maize root meristem: late G/sub 2/, M, G/sub 1/, early S, early G/sub 2/, late S and middle S.

  8. Cell radiosensitivity variation in synchronously-dividing root meristems of Pisum sativum L. and Zea mays L. during the mitotic cycle

    International Nuclear Information System (INIS)

    Gudkov, I.N.; Grodzinsky, D.M.

    1982-01-01

    The cell divisions in pea and maize seedling root meristems were synchronized by treatment with 0.03 per cent hydroxyurea for 24 hours. At different times after block cessation (removing seedlings from hydroxyurea), i.e. according to certain phases and subphases of the mitotic cycle, the seedlings were treated with 60 Co γ-radiation at doses from 3 to 32 Gy. Evaluation of seedling radioresistance by the survival of the main root meristem on the tenth day after irradiation led to the following sequence of cell stages in order of increasing resistance. For the pea root meristem: G 2 , M, late G 1 , early S, late S, middle S and early G 1 . For the maize root meristem: late G 2 , M, G 1 , early S, early G 2 , late S and middle S. (author)

  9. Identity Activities

    Science.gov (United States)

    2016-08-03

    in reaction to their environment. They reflect an individual’s internal or external, conscious or subconscious , overt or covert, voluntary or...identity activities under a range of legal authorities, policy constraints, transnational threats, regional concerns and biases , and most likely...Biography. A baseline and descriptive analytic product that supports the development of the behavioral influences analysis ( BIA ) individual behavioral

  10. [Identity theft

    CERN Multimedia

    Wolinksy, H

    2003-01-01

    "A new survey by the Federal Trade Commission indicates that over the last five years one in four American households has been hit by identity theft, which can result in thieves tapping their victims' credit cards or bank accounts" (1 page).

  11. Designer's Identity

    DEFF Research Database (Denmark)

    Kunrath, Kamila; Cash, Philip; Li-Ying, Jason

    2016-01-01

    A designer’s professional identity (DPI) develops through both education and professional experience, building on core personality traits and innate skills. In this paper a systematic literature review and a secondary narrative review were developed in order to map personal attributes and design...

  12. Challenging Identities

    DEFF Research Database (Denmark)

    depends on the conceptual or ideological constellation in which it takes part. This volume on one hand demonstrates the role of notions of identity in a variety of European contexts, and on the other hand highlights how there may be reasons to challenge the use of the term and corresponding social...

  13. Inhibition of tobacco mosaic virus replication in lateral roots is dependent on an activated meristem-derived signal.

    Science.gov (United States)

    Valentine, T A; Roberts, I M; Oparka, K J

    2002-05-01

    Viral invasion of the root system of Nicotiana benthamiana was studied noninvasively with a tobacco mosaic virus (TMV) vector expressing the green-fluorescent protein (GFP). Lateral root primordia, which developed from the pericycle of primary roots, became heavily infected as they emerged from the root cortex. However, following emergence, a progressive wave of viral inhibition occurred that originated in the lateral-root meristem and progressed towards its base. Excision of source and sink tissues suggested that the inhibition of virus replication was brought about by the basipetal movement of a root meristem signal. When infected plants were inoculated with tobacco rattle virus (TRV) expressing the red-fluorescent protein, DsRed, TRV entered the lateral roots and suppressed the host response, leading to a reestablishment of TMV infection in lateral roots. By infecting GFP-expressing transgenic plants with TMV carrying the complementary GFP sequence it was possible to silence the host GFP, leading to the complete loss of fluorescence in lateral roots. The data suggest that viral inhibition in lateral roots occurs by a gene-silencing-like mechanism that is dependent on the activation of a lateral-root meristem.

  14. Single-cell telomere-length quantification couples telomere length to meristem activity and stem cell development in Arabidopsis.

    Science.gov (United States)

    González-García, Mary-Paz; Pavelescu, Irina; Canela, Andrés; Sevillano, Xavier; Leehy, Katherine A; Nelson, Andrew D L; Ibañes, Marta; Shippen, Dorothy E; Blasco, Maria A; Caño-Delgado, Ana I

    2015-05-12

    Telomeres are specialized nucleoprotein caps that protect chromosome ends assuring cell division. Single-cell telomere quantification in animals established a critical role for telomerase in stem cells, yet, in plants, telomere-length quantification has been reported only at the organ level. Here, a quantitative analysis of telomere length of single cells in Arabidopsis root apex uncovered a heterogeneous telomere-length distribution of different cell lineages showing the longest telomeres at the stem cells. The defects in meristem and stem cell renewal observed in tert mutants demonstrate that telomere lengthening by TERT sets a replicative limit in the root meristem. Conversely, the long telomeres of the columella cells and the premature stem cell differentiation plt1,2 mutants suggest that differentiation can prevent telomere erosion. Overall, our results indicate that telomere dynamics are coupled to meristem activity and continuous growth, disclosing a critical association between telomere length, stem cell function, and the extended lifespan of plants. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Identity transformation

    DEFF Research Database (Denmark)

    Neergaard, Helle; Robinson, Sarah; Jones, Sally

    , as well as the resources they have when they come to the classroom. It also incorporates perspectives from (ii) transformational learning and explores the concept of (iii) nudging from a pedagogical viewpoint, proposing it as an important tool in entrepreneurship education. The study incorporates......This paper develops the concept of ‘pedagogical nudging’ and examines four interventions in an entrepreneurship classroom and the potential it has for student identity transformation. Pedagogical nudging is positioned as a tool, which in the hands of a reflective, professional......) assists students in straddling the divide between identities, the emotions and tensions this elicits, and (iv) transform student understanding. We extend nudging theory into a new territory. Pedagogical nudging techniques may be able to unlock doors and bring our students beyond the unacknowledged...

  16. 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 ...

  17. Antiproliferative and genotoxic effects of nature identical and artificial synthetic food additives of aroma and flavor

    Directory of Open Access Journals (Sweden)

    R. D. M. Nunes

    Full Text Available Abstract This study aimed to analyze the antiproliferative and genotoxic potential of synthetic food flavorings, nature identical passion fruit and artificial vanilla. This assessment used root meristem cells of Allium cepa L., in exposure times of 24 and 48 hours and using doses of 0.2; 0.4 and 0.6 mL. Roots were fixed in Carnoy’s solution, hydrolyzed in hydrochloric acid, stained with acetic orcein and analyzed with optical microscope at 400× magnification, 5,000 cells for each treatment. For data analysis, it was used Chi-square test at 5%. Doses of 0.2 mL at ET 48 h; 0.4 and 0.6 mL at ET 24 and 48 h of passion fruit flavor, and the three doses of the vanilla flavor at ET 24 and 48 h significantly reduced the cell division rate in the meristems of roots, proving to be cytotoxic. Doses of 0.2; 0.4 and 0.6 mL of the passion fruit additive, and the three doses of vanilla tested, in the two exposure times, induced mitotic spindle changes and micronuclei formation in the cells of the test organism used, proving to be genotoxic. Therefore, under the studied conditions, flavoring solutions of vanilla and passion fruit, marketed nationally and internationally, significantly altered the functioning of the cell cycle in root meristem cells of A. cepa.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  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. 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

  5. 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.

  6. 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...

  7. 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.

  8. The QTL GNP1 Encodes GA20ox1, Which Increases Grain Number and Yield by Increasing Cytokinin Activity in Rice Panicle Meristems.

    Science.gov (United States)

    Wu, Yuan; Wang, Yun; Mi, Xue-Fei; Shan, Jun-Xiang; Li, Xin-Min; Xu, Jian-Long; Lin, Hong-Xuan

    2016-10-01

    Cytokinins and gibberellins (GAs) play antagonistic roles in regulating reproductive meristem activity. Cytokinins have positive effects on meristem activity and maintenance. During inflorescence meristem development, cytokinin biosynthesis is activated via a KNOX-mediated pathway. Increased cytokinin activity leads to higher grain number, whereas GAs negatively affect meristem activity. The GA biosynthesis genes GA20oxs are negatively regulated by KNOX proteins. KNOX proteins function as modulators, balancing cytokinin and GA activity in the meristem. However, little is known about the crosstalk among cytokinin and GA regulators together with KNOX proteins and how KNOX-mediated dynamic balancing of hormonal activity functions. Through map-based cloning of QTLs, we cloned a GA biosynthesis gene, Grain Number per Panicle1 (GNP1), which encodes rice GA20ox1. The grain number and yield of NIL-GNP1TQ were significantly higher than those of isogenic control (Lemont). Sequence variations in its promoter region increased the levels of GNP1 transcripts, which were enriched in the apical regions of inflorescence meristems in NIL-GNP1TQ. We propose that cytokinin activity increased due to a KNOX-mediated transcriptional feedback loop resulting from the higher GNP1 transcript levels, in turn leading to increased expression of the GA catabolism genes GA2oxs and reduced GA1 and GA3 accumulation. This rebalancing process increased cytokinin activity, thereby increasing grain number and grain yield in rice. These findings uncover important, novel roles of GAs in rice florescence meristem development and provide new insights into the crosstalk between cytokinin and GA underlying development process.

  9. The effect of distance on moral engagement: Event related potentials and alpha power are sensitive to perspective in a virtual shooting task

    Directory of Open Access Journals (Sweden)

    Kirsten ePetras

    2016-01-01

    Full Text Available In a shooting video game we investigated whether increased distance reduces moral conflict. We measured and analysed the event related potential (ERP, including the N2 component, which has previously been linked to cognitive conflict from competing decision tendencies. In a modified go/nogo task designed to trigger moral conflict participants had to shoot suddenly appearing human like avatars in a virtual reality scene. The scene was seen either from an ego perspective with targets appearing directly in front of the participant or from a bird’s view, where targets were seen from above and more distant. To control for low level visual features, we conducted a visually identical control experiment, where the instruction to shoot was replaced by an instruction to detect. ERP waveforms showed differences between the two tasks as early as in the N1 time-range, with higher N1 amplitudes for the close perspective in the shoot task. Additionally, we found that pre-stimulus alpha power was significantly decreased in the ego, compared to the bird's view only for the shoot but not for the detect task. In the N2 time window, we observed main amplitude effects for response (nogo > go and distance (ego > bird perspective but no interaction with task type (shoot vs detect. We argue that the pre-stimulus and N1 effects can be explained by reduced attention and arousal in the distance condition when people are instructed to shoot. The lack of interaction in the N2 across tasks suggests that at that time point, the moral conflict is already resolved and response execution dominates. We discuss potential implications for real life shooting situations, especially considering recent developments in drone shootings which are per definition of a distant view.

  10. The Effect of Distance on Moral Engagement: Event Related Potentials and Alpha Power are Sensitive to Perspective in a Virtual Shooting Task.

    Science.gov (United States)

    Petras, Kirsten; Ten Oever, Sanne; Jansma, Bernadette M

    2015-01-01

    In a shooting video game we investigated whether increased distance reduces moral conflict. We measured and analyzed the event related potential (ERP), including the N2 component, which has previously been linked to cognitive conflict from competing decision tendencies. In a modified Go/No-go task designed to trigger moral conflict participants had to shoot suddenly appearing human like avatars in a virtual reality scene. The scene was seen either from an ego perspective with targets appearing directly in front of the participant or from a bird's view, where targets were seen from above and more distant. To control for low level visual features, we added a visually identical control condition, where the instruction to "shoot" was replaced by an instruction to "detect." ERP waveforms showed differences between the two tasks as early as in the N1 time-range, with higher N1 amplitudes for the close perspective in the "shoot" task. Additionally, we found that pre-stimulus alpha power was significantly decreased in the ego, compared to the bird's view only for the "shoot" but not for the "detect" task. In the N2 time window, we observed main amplitude effects for response (No-go > Go) and distance (ego > bird perspective) but no interaction with task type (shoot vs. detect). We argue that the pre-stimulus and N1 effects can be explained by reduced attention and arousal in the distance condition when people are instructed to "shoot." These results indicate a reduced moral engagement for increased distance. The lack of interaction in the N2 across tasks suggests that at that time point response execution dominates. We discuss potential implications for real life shooting situations, especially considering recent developments in drone shootings which are per definition of a distant view.

  11. 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...

  12. Mediating Identity

    DEFF Research Database (Denmark)

    Kjærgaard, Annemette Leonhardt; Morsing, Mette; Ravasi, Davide

    2011-01-01

    This paper reports a longitudinal field study on the effects of positive media coverage on the reconstruction of organizational identity. The study highlights how intense positive coverage – to the point of turning an organization into a ‘celebrity’– influences both the way members understand...... their organization (sensemaking effect) and the gratification they derive from its positive representation (self-enhancement effect). Our findings suggest that positive media representations foster members' alignment around an emergent new understanding of what their organization is. Over time, however, celebrity...

  13. Unravelling identities

    OpenAIRE

    2007-01-01

    Abstract The decision to go to war by the government of the day is assumed to be a decision taken on behalf of all citizens of the nation, conceived as a collective united by a harmony of interests. Yet in the case of the Iraq War, there is clearly no unified voice of support from the British people. There is division between the state and its citizens, and the latter also reflect the multilayered identities of an increasingly multicultural society. How do individuals displaying mu...

  14. 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.

  15. miR396 affects mycorrhization and root meristem activity in the legume Medicago truncatula.

    Science.gov (United States)

    Bazin, Jérémie; Khan, Ghazanfar Abbas; Combier, Jean-Philippe; Bustos-Sanmamed, Pilar; Debernardi, Juan Manuel; Rodriguez, Ramiro; Sorin, Céline; Palatnik, Javier; Hartmann, Caroline; Crespi, Martin; Lelandais-Brière, Christine

    2013-06-01

    The root system is crucial for acquisition of resources from the soil. In legumes, the efficiency of mineral and water uptake by the roots may be reinforced due to establishment of symbiotic relationships with mycorrhizal fungi and interactions with soil rhizobia. Here, we investigated the role of miR396 in regulating the architecture of the root system and in symbiotic interactions in the model legume Medicago truncatula. Analyses with promoter-GUS fusions suggested that the mtr-miR396a and miR396b genes are highly expressed in root tips, preferentially in the transition zone, and display distinct expression profiles during lateral root and nodule development. Transgenic roots of composite plants that over-express the miR396b precursor showed lower expression of six growth-regulating factor genes (MtGRF) and two bHLH79-like target genes, as well as reduced growth and mycorrhizal associations. miR396 inactivation by mimicry caused contrasting tendencies, with increased target expression, higher root biomass and more efficient colonization by arbuscular mycorrhizal fungi. In contrast to MtbHLH79, repression of three GRF targets by RNA interference severely impaired root growth. Early activation of mtr-miR396b, concomitant with post-transcriptional repression of MtGRF5 expression, was also observed in response to exogenous brassinosteroids. Growth limitation in miR396 over-expressing roots correlated with a reduction in cell-cycle gene expression and the number of dividing cells in the root apical meristem. These results link the miR396 network to the regulation of root growth and mycorrhizal associations in plants. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  16. 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 ...

  17. 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 ...

  18. 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

  19. 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...

  20. 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…

  1. 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.

  2. 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…

  3. 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

  4. 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...

  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. 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 ...

  7. miRNA and Degradome Sequencing Reveal miRNA and Their Target Genes That May Mediate Shoot Growth in Spur Type Mutant “Yanfu 6”

    Science.gov (United States)

    Song, Chunhui; Zhang, Dong; Zheng, Liwei; Zhang, Jie; Zhang, Baojuan; Luo, Wenwen; Li, Youmei; Li, Guangfang; Ma, Juanjuan; Han, Mingyu

    2017-01-01

    The spur-type growth habit in apple trees is characterized by short internodes, increased number of fruiting spurs, and compact growth that promotes flowering and facilitates management practices, such as pruning. The molecular mechanisms responsible for regulating spur-type growth have not been elucidated. In the present study, miRNAs and the expression of their potential target genes were evaluated in shoot tips of “Nagafu 2” (CF) and spur-type bud mutation “Yanfu 6” (YF). A total of 700 mature miRNAs were identified, including 202 known apple miRNAs and 498 potential novel miRNA candidates. A comparison of miRNA expression in CF and YF revealed 135 differentially expressed genes, most of which were downregulated in YF. YF also had lower levels of GA, ZR, IAA, and ABA hormones, relative to CF. Exogenous applications of GA promoted YF shoot growth. Based on the obtained results, a regulatory network involving plant hormones, miRNA, and their potential target genes is proposed for the molecular mechanism regulating the growth of YF. miRNA164, miRNA166, miRNA171, and their potential targets, and associated plant hormones, appear to regulate shoot apical meristem (SAM) growth. miRNA159, miRNA167, miRNA396, and their potential targets, and associated plant hormones appear to regulate cell division and internode length. This study provides a foundation for further studies designed to elucidate the mechanism underlying spur-type apple architecture. PMID:28424721

  8. 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.

  9. 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)

  10. Effect of the gamma radiation in the metabolic activity of the apical meristem of asparagus (Asparagus officinalis)

    International Nuclear Information System (INIS)

    Sanchez E, A.; Orozco A, J.A.; Troncoso R, R.; Ojeda C, A.J.; Mercado R, J.N.; Gardea B, A.; Tiznado H, M.E.; Melendrez A, R.

    2007-01-01

    The asparagus (Asparagus officinalis) is an agricultural product whose production generates a great quantity of wages as well as foreign currencies for the country because a great part of its production is exported to international markets. In direct reason to the high metabolic activity of the apical meristem, this product it possesses a short shelf life under good conditions of commercialization. Due to the above mentioned, the present work had as objective to evaluate the effect of the gamma radiation in the metabolic activity of the apical meristem of turions of asparagus during the postharvest. Turions of asparagus variety Brock of standard quality was treated with gamma radiation to absorbed dose of 1.0, 1.5, 2.0, 2.5 and 3.0 kGy using an irradiator of 60 Co and stored in one controlled temperature camera maintained at 2 C during 8 days. During the experiment, the camera stayed in darkness and under conditions of high relative humidity by means of the water aspersion. Immediately before the one treatment and after 1, 2, 4 and 8 days of storage, the asparagus were sampled to evaluate the breathing speed (VRCG) by means of gas chromatography and scanning differential calorimetry (VRCDB), ethylene production (PE) by means of gas chromatography and production of metabolic heat of the apical meristem of the asparagus by means of scanning differential calorimetry (Q). Its were not found effects due to the gamma radiation in the variables of VRCG, VRCDB and Q. However, for the PE case, it was found that the doses of 1.5 and 2.5 reduced the PE from the first day of storage, while the 3 kGy dose achievement to eliminate completely the ethylene production from the first day of storage. It was concluded that the gamma radiation at the used levels in the present experiment doesn't reduce the metabolic activity of the apical meristem of the turion of asparagus although it can to improve the postharvest quality from the asparagus when reducing the ethylene production

  11. A dynamic genetic-hormonal regulatory network model explains multiple cellular behaviors of the root apical meristem of Arabidopsis thaliana.

    Science.gov (United States)

    García-Gómez, Mónica L; Azpeitia, Eugenio; Álvarez-Buylla, Elena R

    2017-04-01

    The study of the concerted action of hormones and transcription factors is fundamental to understand cell differentiation and pattern formation during organ development. The root apical meristem of Arabidopsis thaliana is a useful model to address this. It has a stem cell niche near its tip conformed of a quiescent organizer and stem or initial cells around it, then a proliferation domain followed by a transition domain, where cells diminish division rate before transiting to the elongation zone; here, cells grow anisotropically prior to their final differentiation towards the plant base. A minimal model of the gene regulatory network that underlies cell-fate specification and patterning at the root stem cell niche was proposed before. In this study, we update and couple such network with both the auxin and cytokinin hormone signaling pathways to address how they collectively give rise to attractors that correspond to the genetic and hormonal activity profiles that are characteristic of different cell types along A. thaliana root apical meristem. We used a Boolean model of the genetic-hormonal regulatory network to integrate known and predicted regulatory interactions into alternative models. Our analyses show that, after adding some putative missing interactions, the model includes the necessary and sufficient components and regulatory interactions to recover attractors characteristic of the root cell types, including the auxin and cytokinin activity profiles that correlate with different cellular behaviors along the root apical meristem. Furthermore, the model predicts the existence of activity configurations that could correspond to the transition domain. The model also provides a possible explanation for apparently paradoxical cellular behaviors in the root meristem. For example, how auxin may induce and at the same time inhibit WOX5 expression. According to the model proposed here the hormonal regulation of WOX5 might depend on the cell type. Our results

  12. A dynamic genetic-hormonal regulatory network model explains multiple cellular behaviors of the root apical meristem of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Mónica L García-Gómez

    2017-04-01

    Full Text Available The study of the concerted action of hormones and transcription factors is fundamental to understand cell differentiation and pattern formation during organ development. The root apical meristem of Arabidopsis thaliana is a useful model to address this. It has a stem cell niche near its tip conformed of a quiescent organizer and stem or initial cells around it, then a proliferation domain followed by a transition domain, where cells diminish division rate before transiting to the elongation zone; here, cells grow anisotropically prior to their final differentiation towards the plant base. A minimal model of the gene regulatory network that underlies cell-fate specification and patterning at the root stem cell niche was proposed before. In this study, we update and couple such network with both the auxin and cytokinin hormone signaling pathways to address how they collectively give rise to attractors that correspond to the genetic and hormonal activity profiles that are characteristic of different cell types along A. thaliana root apical meristem. We used a Boolean model of the genetic-hormonal regulatory network to integrate known and predicted regulatory interactions into alternative models. Our analyses show that, after adding some putative missing interactions, the model includes the necessary and sufficient components and regulatory interactions to recover attractors characteristic of the root cell types, including the auxin and cytokinin activity profiles that correlate with different cellular behaviors along the root apical meristem. Furthermore, the model predicts the existence of activity configurations that could correspond to the transition domain. The model also provides a possible explanation for apparently paradoxical cellular behaviors in the root meristem. For example, how auxin may induce and at the same time inhibit WOX5 expression. According to the model proposed here the hormonal regulation of WOX5 might depend on the cell

  13. Further identification of endogenous gibberellins in the shoots of pea, line G2

    International Nuclear Information System (INIS)

    Halinska, A.; Davies, P.J.; Lee, J.W.; Zhu, Yuxian

    1989-01-01

    To interpret the metabolism of radiolabeled gibberellins A 12 -aldehyde and A 12 in shoots of pea (Pisum sativum L.), the identity of the radiolabeled peaks has to be determined and the endogenous presence of the gibberellins demonstrated. High specific activity [ 14 C]GA 12 and [ 14 C]GA 12 -aldehyde were synthesized using a pumpkin endosperm enzyme preparation, and purified by high performance liquid chromatography (HPLC). [ 14 C]GA 12 was supplied to upper shoots of pea, line G2, to produce radiolabeled metabolites on the 13-OH pathway. Endogenous compounds copurifying with the [ 14 C]GAs on HPLC were analyzed by gas chromatography-mass spectrometry. The endogenous presence of GA 53 , GA 44 , GA 19 and GA 20 was demonstrated and their HPLC peak identity ascertained. The 14 C was progressively diluted in GAs further down the pathway, proportional to the levels found in the tissue and inversely proportional to the speed of metabolism, ranging from 63% in GA 53 to 4% in GA 20 . Calculated levels of GA 20 , GA 19 , GA 44 , and GA 53 were 42, 8, 10, and 0.5 nanograms/gram, respectively

  14. "Invisible During My Own Crisis": Responses of LGBT People of Color to the Orlando Shooting.

    Science.gov (United States)

    Ramirez, Johanna L; Gonzalez, Kirsten A; Galupo, M Paz

    2018-01-01

    On June 12, 2016, the Pulse nightclub in Orlando, Florida was the target of one of the country's deadliest mass shootings. Pulse, a gay nightclub, was hosting a Latin Pride Night the evening of the tragedy, which resulted in the death of 49 victims and 53 casualties, over 90% of whom were lesbian, gay, bisexual, and transgender (LGBT) Latinx people, specifically. The present research investigates the narrative responses from LGBT people of color (LGBT-POC) following the tragedy. Results included an analysis of 94 participant narrative responses. Results were collected online from a sample of LGBT-POC with varying sexual, gender, and racial identities. Thematic analysis revealed four major themes: (1) Violence is Not New for LGBT-POC; (2) Personal Identification with Victims; (3) Lack of Intersectionality in Others' Responses to Orlando; and (4) Acknowledgment of Intersectionality across LGBT-POC. Discussion focuses on describing the ways in which LGBT-POC responded to the shooting regarding their multiple minority identities. Implications of this research reinforce the need for continued intersectional research with LGBT-POC.

  15. Federated Identity Management

    OpenAIRE

    Chadwick, David W.

    2009-01-01

    Abstract. This paper addresses the topic of federated identity management. It discusses in detail the following topics: what is digital identity, what is identity management, what is federated identity management, Kim Camerons 7 Laws of Identity, how can we protect the users privacy in a federated environment, levels of assurance, some past and present federated identity management systems, and some current research in FIM.

  16. 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,

  17. Identical and shifted identical bands

    International Nuclear Information System (INIS)

    Dodder, R.S; Jones, E.F.; Hamilton, J.H.

    1997-01-01

    Spontaneous fission of 252 Cm was studied with 72 large Compton suppressed Ge detectors in Gamma sphere. New isotopes 160 Sm and 162 Gd were identified. Through X-ray-γ and γ-γ-γ) coincidence measurements, level energies were established to spins 14 + to 20 + in 152 , 154 156 60 Nd 92 94 96 , 156 , 158 , 160 62 Sm 94 , 96 , 98 , and 160 , 162 64 Gd 96 , 98 . These nuclei exhibit a remarkable variety of identical bands and bands where the energies and moments of inertia are shifted by the same constant amount for every spin state from 2 + to 12 + for various combinations of nuclei differing by 2n, 4n, 2p, 4p, and α

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. Arabidopsis thaliana gonidialess A/Zuotin related factors (GlsA/ZRF) are essential for maintenance of meristem integrity.

    Science.gov (United States)

    Guzmán-López, José Alfredo; Abraham-Juárez, María Jazmín; Lozano-Sotomayor, Paulina; de Folter, Stefan; Simpson, June

    2016-05-01

    Observation of a differential expression pattern, including strong expression in meristematic tissue of an Agave tequilana GlsA/ZRF ortholog suggested an important role for this gene during bulbil formation and developmental changes in this species. In order to better understand this role, the two GlsA/ZFR orthologs present in the genome of Arabidopsis thaliana were functionally characterized by analyzing expression patterns, double mutant phenotypes, promoter-GUS fusions and expression of hormone related or meristem marker genes. Patterns of expression for A. thaliana show that GlsA/ZFR genes are strongly expressed in SAMs and RAMs in mature plants and developing embryos and double mutants showed multiple changes in morphology related to both SAM and RAM tissues. Typical double mutants showed stunted growth of aerial and root tissue, formation of multiple ectopic meristems and effects on cotyledons, leaves and flowers. The KNOX genes STM and BP were overexpressed in double mutants whereas CLV3, WUSCHEL and AS1 were repressed and lack of AtGlsA expression was also associated with changes in localization of auxin and cytokinin. These results suggest that GlsA/ZFR is an essential component of the machinery that maintains the integrity of SAM and RAM tissue and underline the potential to identify new genes or gene functions based on observations in non-model plants.

  7. Heat-shock protein 40 is the key farnesylation target in meristem size control, abscisic acid signaling, and drought resistance.

    Science.gov (United States)

    Barghetti, Andrea; Sjögren, Lars; Floris, Maïna; Paredes, Esther Botterweg; Wenkel, Stephan; Brodersen, Peter

    2017-11-15

    Protein farnesylation is central to molecular cell biology. In plants, protein farnesyl transferase mutants are pleiotropic and exhibit defective meristem organization, hypersensitivity to the hormone abscisic acid, and increased drought resistance. The precise functions of protein farnesylation in plants remain incompletely understood because few relevant farnesylated targets have been identified. Here, we show that defective farnesylation of a single factor-heat-shock protein 40 (HSP40), encoded by the J2 and J3 genes-is sufficient to confer ABA hypersensitivity, drought resistance, late flowering, and enlarged meristems, indicating that altered function of chaperone client proteins underlies most farnesyl transferase mutant phenotypes. We also show that expression of an abiotic stress-related microRNA (miRNA) regulon controlled by the transcription factor SPL7 requires HSP40 farnesylation. Expression of a truncated SPL7 form mimicking its activated proteolysis fragment of the membrane-bound SPL7 precursor partially restores accumulation of SPL7-dependent miRNAs in farnesyl transferase mutants. These results implicate the pathway directing SPL7 activation from its membrane-bound precursor as an important target of farnesylated HSP40, consistent with our demonstration that HSP40 farnesylation facilitates its membrane association. The results also suggest that altered gene regulation via select miRNAs contributes to abiotic stress-related phenotypes of farnesyl transferase mutants. © 2017 Barghetti et al.; Published by Cold Spring Harbor Laboratory Press.

  8. Investigation of protective effects of Erythrina velutina extract against MMS induced damages in the root meristem cells of Allium cepa

    Directory of Open Access Journals (Sweden)

    Deborah S. B. S. Silva

    2013-04-01

    Full Text Available Erythrina velutina Willd., Fabaceae, is a medicinal plant that can be found in the tropics and subtropics, including in the semi-arid northeastern Brazil. It is commonly used in folk medicine to treat anxiety, agitation and insomnia. E. velutina has been known to present analgesic, anti-inflammatory and antibacterial activities, however, it is unknown if this plant present a protective effect on DNA. We assessed the antigenotoxic effect of E. velutina against the genotoxic effects induced by MMS in the root meristem cells of Allium cepa. Three concentrations of the aqueous extract (100, 200 and 400 mg/L of this medicinal plant were used in three different types of treatment (pre-, post- and simultaneous. The effects of the extracts on the root meristem cells of A. cepa were analyzed at both macroscopic and microscopic levels. Protective effects were observed at higher concentrations in pre-treatment and in simultaneous treatment. The results suggest that E. velutina may present antigenotoxic properties and demonstrate its chemopreventive potential.

  9. Plant-specific Histone Deacetylases HDT½ Regulate GIBBERELLIN 2-OXIDASE 2 Expression to Control Arabidopsis Root Meristem Cell Number

    KAUST Repository

    Li, Huchen

    2017-08-31

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription factors and chromatin-remodelling factors have been implicated in regulating the switch from stem cells to transit-amplifying cells. Here we show that two Arabidopsis thaliana paralogs encoding plant-specific histone deacetylases, HDT1 and HDT2, regulate a second switch from transit-amplifying cells to expanding cells. Knockdown of HDT½ (hdt1,2i) results in an earlier switch and causes a reduced RM cell number. Our data show that HDT½ negatively regulate the acetylation level of the C19-GIBBERELLIN 2-OXIDASE 2 (GA2ox2) locus and repress the expression of GA2ox2 in the RM and elongation zone. Overexpression of GA2ox2 in the RM phenocopies the hdt1,2i phenotype. Conversely, knockout of GA2ox2 partially rescues the root growth defect of hdt1,2i. These results suggest that by repressing the expression of GA2ox2, HDT½ likely fine-tune gibberellin metabolism and they are crucial for regulating the switch from cell division to expansion to determine RM cell number. We propose that HDT½ function as part of a mechanism that modulates root growth in response to environmental factors.

  10. 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, ...

  11. 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.

  12. Somatic embryogenesis in plantain cultivar 'FHIA - 25' (AAB from meristem tips

    Directory of Open Access Journals (Sweden)

    Dayana Rodríguez González

    2015-07-01

    Full Text Available Plantain cultivar 'FHIA – 25' (AAB shows high yielding qualities and high resistance to Black Sigatoka disease, but its sugar content in the fruit is low, so a regeneration method at cell level is necessary, such as somatic embryogenesis supported by biotechnological tools to improve fruit quality. This work was performed with the aim of establishing a plant regeneration method via somatic embryogenesis using initial explants of shoot apices from axillary buds in liquid culture medium. Homogenous embryogenic cell suspensions were obtained from mentioned explants. The highest cellular multiplication rates were achieved at 3,0% density. The incubation of somatic embryos during 30 days in the maturation culture medium permitted to increase germination. During the acclimatization stage, plants regenerated from somatic embryos, as well as plants from organogenesis, showed a high survival percentage (98 and 97 respectively, without somaclonal variation.

  13. 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.

  14. 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

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Organization of the root apical meristem in Linum usitatissimum L. grown at 25°C and 7°C

    Directory of Open Access Journals (Sweden)

    A. Kadej

    2015-01-01

    Full Text Available In the first days of intensive growth of the Linum usitatissimum root, the central part of the apical meristem exhibits usually a 4-tier organization. When growth ceases reorganization of the cell arrangement occurs. It starts by periclinal division of the subprotodermal initials, whose derivatives are forming the secondary columella in the central part of the root cap.

  7. 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.

  8. 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.

  9. 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.

  10. Lateral root initiation and formation within the parental root meristem of Cucurbita pepo: is auxin a key player?

    Science.gov (United States)

    Ilina, Elena L; Kiryushkin, Alexey S; Semenova, Victoria A; Demchenko, Nikolay P; Pawlowski, Katharina; Demchenko, Kirill N

    2018-04-19

    In some plant families, including Cucurbitaceae, initiation and development of lateral roots (LRs) occur in the parental root apical meristem. The objective of this study was to identify the general mechanisms underlying LR initiation (LRI). Therefore, the first cellular events leading to LRI as well as the role of auxin in this process were studied in the Cucurbita pepo root apical meristem. Transgenic hairy roots harbouring the auxin-responsive promoter DR5 fused to different reporter genes were used for visualizing of cellular auxin response maxima (ARMs) via confocal laser scanning microscopy and 3-D imaging. The effects of exogenous auxin and auxin transport inhibitors on root branching were analysed. The earliest LRI event involved a group of symmetric anticlinal divisions in pericycle cell files at a distance of 250-350 µm from the initial cells. The visualization of the ARMs enabled the precise detection of cells involved in determining the site of LR primordium formation. A local ARM appeared in sister cells of the pericycle and endodermis files before the first division. Cortical cells contributed to LR development after the anticlinal divisions in the pericycle via the formation of an ARM. Exogenous auxins did not increase the total number of LRs and did not affect the LRI index. Although exogenous auxin transport inhibitors acted in different ways, they all reduced the number of LRs formed. Literature data, as well as results obtained in this study, suggest that the formation of a local ARM before the first anticlinal formative divisions is the common mechanism underlying LRI in flowering plants. We propose that the mechanisms of the regulation of root branching are independent of the position of the LRI site relative to the parental root tip.

  11. The early inflorescence of Arabidopsis thaliana demonstrates positional effects in floral organ growth and meristem patterning.

    Science.gov (United States)

    Plackett, Andrew R G; Powers, Stephen J; Phillips, Andy L; Wilson, Zoe A; Hedden, Peter; Thomas, Stephen G

    2018-06-01

    Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradicted by the existence of mutants with phenotypes visible in early flowers only. This phenomenon is demonstrated by mutants partially impaired in the biosynthesis of the phytohormone gibberellin (GA), in which floral organ growth is retarded in the first flowers to be produced but has recovered spontaneously by the 10th flower. We presently lack systematic data from multiple flowers across the Arabidopsis inflorescence to explain such changes. Using mutants of the GA 20-OXIDASE (GA20ox) GA biosynthesis gene family to manipulate endogenous GA levels, we investigated the dynamics of changing floral organ growth across the early Arabidopsis inflorescence (flowers 1-10). Modelling of floral organ lengths identified a significant, GA-independent gradient of increasing stamen length relative to the pistil in the wild-type inflorescence that was separable from other, GA-dependent effects. It was also found that the first flowers exhibited unstable organ patterning in contrast to later flowers and that this instability was prolonged by exogenous GA treatment. These findings indicate that the development of individual flowers is influenced by hitherto unknown factors acting across the inflorescence and also suggest novel functions for GA in floral patterning.

  12. Identity after Death

    DEFF Research Database (Denmark)

    Gerstrøm, Anna

    2015-01-01

    Purpose: The purpose of this paper is to explore how legacy organizational identity and death relate to each other and, thereby, contribute to closing the gap in knowledge on organizational identity constructions in times of death. Design/methodology/approach: The paper opted for an exploratory....../value: This paper addresses an apparent gap in the literature on identity and death; exploring identity narratives in a bankrupted bank, the paper considers constructions of legacy organizational identities in times of disruptive death....

  13. Asian American Adolescent Identity

    OpenAIRE

    Ohm, Julie Juhye

    1999-01-01

    The formation of ego identity in Asian American late adolescents attending Virginia Tech was examined within the frameworks of Erikson's psychosocial theory and Berry, Trimble, and Olmedo's model of acculturation. Ego identity was measured using the Achieved sub-scale of the Revised Version of the Extended Objective Measure of Ego Identity Status, an instrument based on the theoretical constructs of Erikson. Ethnic identity was measured using the Multigroup Ethnic Identity Measure and America...

  14. 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

  15. 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

  16. 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.

  17. Domestication-driven Gossypium profilin 1 (GhPRF1) gene transduces early flowering phenotype in tobacco by spatial alteration of apical/floral-meristem related gene expression.

    Science.gov (United States)

    Pandey, Dhananjay K; Chaudhary, Bhupendra

    2016-05-13

    Plant profilin genes encode core cell-wall structural proteins and are evidenced for their up-regulation under cotton domestication. Notwithstanding striking discoveries in the genetics of cell-wall organization in plants, little is explicit about the manner in which profilin-mediated molecular interplay and corresponding networks are altered, especially during cellular signalling of apical meristem determinacy and flower development. Here we show that the ectopic expression of GhPRF1 gene in tobacco resulted in the hyperactivation of apical meristem and early flowering phenotype with increased flower number in comparison to the control plants. Spatial expression alteration in CLV1, a key meristem-determinacy gene, is induced by the GhPRF1 overexpression in a WUS-dependent manner and mediates cell signalling to promote flowering. But no such expression alterations are recorded in the GhPRF1-RNAi lines. The GhPRF1 transduces key positive flowering regulator AP1 gene via coordinated expression of FT4, SOC1, FLC1 and FT1 genes involved in the apical-to-floral meristem signalling cascade which is consistent with our in silico profilin interaction data. Remarkably, these positive and negative flowering regulators are spatially controlled by the Actin-Related Protein (ARP) genes, specifically ARP4 and ARP6 in proximate association with profilins. This study provides a novel and systematic link between GhPRF1 gene expression and the flower primordium initiation via up-regulation of the ARP genes, and an insight into the functional characterization of GhPRF1 gene acting upstream to the flowering mechanism. Also, the transgenic plants expressing GhPRF1 gene show an increase in the plant height, internode length, leaf size and plant vigor. Overexpression of GhPRF1 gene induced early and increased flowering in tobacco with enhanced plant vigor. During apical meristem determinacy and flower development, the GhPRF1 gene directly influences key flowering regulators through ARP

  18. 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.

  19. 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.)

  20. 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/.

  1. Identity Work and Emotions

    DEFF Research Database (Denmark)

    Winkler, Ingo

    2018-01-01

    This paper reviews the empirical literature on identity work and identifies two distinct approaches to incorporating emotion. The majority of empirical studies use emotion to describe the experiences of identity work. In doing so, the authors (a) mention the emotions that people feel in situations...... that trigger identity work, (b) illustrate identity work as an emotional endeavour, and (c) describe the emotional impact of successful and unsuccessful identity work. There is also an emerging literature that examines the mutual constitution of emotions and identity work. These authors address emotional...... labour, affective social identification, emotional attachment and detachment, and humour when studying identity work. This paper suggests that, to understand better the relation between emotions and identity work, future research should examine the role of emotions in problematizing identity...

  2. Identity and identity conflict in the workplace

    NARCIS (Netherlands)

    K.E. Horton (Kate); P.S. Bayerl (Saskia); G. Belschak-Jacobs (Gabriele)

    2014-01-01

    textabstractAs individuals, we define ourselves according to various characteristics that include our values and beliefs. This gives us our identity. As organisations become increasingly complex, understanding the concept of identity conflict may mean the difference between success and failure.

  3. Conservação in vitro do germoplasma de capim-elefante por meio da micropropagação de meristemas axilares In vitro conservation of elephantgrass germplasm of micropropagation of axillary meristems

    Directory of Open Access Journals (Sweden)

    Maria Coletta Vidigal

    1998-09-01

    Full Text Available Na conservação m vitro do capim-elefante foi observado que, ao longo dos subcultivos sucessivos de meristemas picais, ocorre gradual perda de vigor nas plântulas. Essa limitação torna necessária a reintrodução de acessos na coleção, comprometendo a eficiência do processo. Visando solucionar o problema, foi conduzido um estudo com 51 cultivares de capimelefante, onde, na repicagem efetuada a cada 4 a 6 meses, foram inoculados meristemas axilares da plântula, dispostos horizontalmente sobre meio MS, adicionado ou não de ácido naftalenoacético (ANA. Neste ciclo, que durou 45 dias, foram avaliadas as seguintes variáveis: número e comprimento dos explantes, gemas brotadas por explante, início e vigor da brotação, número de brotos desenvolvidos e percentagem de morte. Os resultados sugerem que esse método melhorou o vigor acentuadamente; embora as respostas, com e sem adição de ANA ao meio, tenham sido muito variadas entre cultivares. Apenas a cv. Mercker Comum Pinda não apresentou resposta satisfatória, devendo ser futuramente submetida a outras alternativas para propagação. Com base na produção de brotos, as cvs. Napier e Sem Pêlo apresentaram o melhor desempenho, na presença de ANA. O método mostrou-se promissor também pelo uso mínimo de reguladores do crescimento, reduzindo custos e a possibilidade de mutações.The continuous utiliwtion of explants obtainedfrom cultured apical meristems limits elephantgrass in vitro conservation because of gradual loss of vigor. Such a restriction makes it necessary to periodícally replace accessions in the coilection, reducing the efficiency of the technique. To overcome this problem, a study was carried out with 51 elephantgrass cultivars, where reculturing was conducted every 4 to 6 months using in vitro seediing axiliary meristems, with or without the addition of naphtaleneacetic acid (NAA to the MS culture médium. During this reculturing cycle, which lasted 45 days, the

  4. On Fay identity

    International Nuclear Information System (INIS)

    Michev, Iordan P.

    2006-01-01

    In the first part of this paper we consider the transformation of the cubic identities for general Korteweg-de Vries (KdV) tau functions from [Mishev, J. Math. Phys. 40, 2419-2428 (1999)] to the specific identities for trigonometric KdV tau functions. Afterwards, we consider the Fay identity as a functional equation and provide a wide set of solutions of this equation. The main result of this paper is Theorem 3.4, where we generalize the identities from Mishev. An open problem is the transformation of the cubic identities from Mishev to the specific identities for elliptic KdV tau functions

  5. Identities as organizational practices

    DEFF Research Database (Denmark)

    Oshima, Sae; Asmuß, Birte

    Identity has been widely acknowledged as playing a central role in various organizational processes, yet there is still a need to better understand the dynamics and functions of identity work in modern organizations. The present paper is centered within this concern, and examines identity......) reveal the intersubjective, multimodal and embodied nature of identity work; 2) demonstrate identity work as organizational practices, used in order to accomplish specific actions; and 3) pose a question on the view on identity as a layered/leveled phenomenon....

  6. 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.

  7. A ¤Terminal Flower-1¤-like gene from perennial ryegrass involved in floral transition and axillary meristem identity

    DEFF Research Database (Denmark)

    Jensen, C.S.; Salchert, K.; Nielsen, K.K.

    2001-01-01

    12 weeks to induce flowering. During this period a decrease in LpTFL1 message was detected in the ryegrass apex. However, upon subsequent induction with elevated temperatures and long-day photoperiods, LpTFL1 message levels increased and reached a maximum M:hen the ryegrass apex has formed visible...

  8. 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.

  9. 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…

  10. 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 ...

  11. 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…

  12. 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.

  13. 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

  14. 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 ...

  15. 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).

  16. 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 ...

  17. 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.

  18. 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 ...

  19. 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 ...

  20. 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.

  1. 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.

  2. 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

  3. 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…

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. 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.

  10. 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.

  11. 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 ...

  12. 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.

  13. 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- ...

  14. The Supermalt identity

    DEFF Research Database (Denmark)

    Bech-Larsen, Tino; Esbjerg, Lars; Grunert, Klaus G.

    2007-01-01

    on consumers' self-identities. The second part explored the role of food and beverage products in the construction of self-identities. The final part focused on the construction of brand identity for Supermalt. Findings - The article provides information on the self-identities constructed by Afro......-Caribbean informants. The food and beverage consumption of informants reflects their mixed cultural identity. The brand identity Supermalt appears to be malleable, with ample room for consumer co-construction. Perceptions of brand identity differ markedly among informants, who are all able to construct Supermalt......Purpose - The objective of this article is to conduct a case study of the Supermalt brand of malt beer, which has become the preferred beverage of Afro-Caribbean consumers in Brixton on a very limited marketing budget. Design/methodology/approach - The article uses the concepts of personal identity...

  15. Researching Identity and Interculturality

    DEFF Research Database (Denmark)

    Lønsmann, Dorte

    2016-01-01

    Review of: Researching Identity and Interculturality / by F. Dervin and K. Risager (eds.). Routledge 2015, 245 pp.......Review of: Researching Identity and Interculturality / by F. Dervin and K. Risager (eds.). Routledge 2015, 245 pp....

  16. Understanding Identity and Organizations

    DEFF Research Database (Denmark)

    Christensen, Lars Thøger

    2013-01-01

    The article reviews the book "Understanding Identity and Organizations," by Kate Kenny, Andrea Whitle, and Hugh Wilmott.......The article reviews the book "Understanding Identity and Organizations," by Kate Kenny, Andrea Whitle, and Hugh Wilmott....

  17. Components of Sexual Identity

    Science.gov (United States)

    Shively, Michael G.; DeCecco, John P.

    1977-01-01

    This paper examines the four components of sexual identity: biological sex, gender identity, social sex-role, and sexual orientation. Theories about the development of each component and how they combine and conflict to form the individual's sexual identity are discussed. (Author)

  18. Mobile Identity Management

    NARCIS (Netherlands)

    Hoepman, J.J.

    2011-01-01

    Identity management consists of the processes and all underlying technologies for the creation, management, and usage of digital identities. Business rely on identity management systems to simplify the management of access rights to their systems and services for both their employees and their

  19. Being Tolerant about Identity?

    NARCIS (Netherlands)

    van Rooij, R.; Gutzmann, D.; Köpping, J.; Meier, C.

    2014-01-01

    Identity and identification are very important concepts in philosophy and logic. They are crucial for the analysis of quantification and for counting. According to some philosophers, many examples that are supposed to show that identity is contingent, in fact show that the notion of identity is

  20. 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.

  1. 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

  2. Expression patterns of Passiflora edulis APETALA1/FRUITFULL homologues shed light onto tendril and corona identities

    Directory of Open Access Journals (Sweden)

    Livia C. T. Scorza

    2017-02-01

    Full Text Available Abstract Background Passiflora (passionflowers makes an excellent model for studying plant evolutionary development. They are mostly perennial climbers that display axillary tendrils, which are believed to be modifications of the inflorescence. Passionflowers are also recognized by their unique flower features, such as the extra whorls of floral organs composed of corona filaments and membranes enclosing the nectary. Although some work on Passiflora organ ontogeny has been done, the developmental identity of both Passiflora tendrils and the corona is still controversial. Here, we combined ultrastructural analysis and expression patterns of the flower meristem and floral organ identity genes of the MADS-box AP1/FUL clade to reveal a possible role for these genes in the generation of evolutionary novelties in Passiflora. Results We followed the development of structures arising from the axillary meristem from juvenile to adult phase in P. edulis. We further assessed the expression pattern of P. edulis AP1/FUL homologues (PeAP1 and PeFUL, by RT-qPCR and in situ hybridization in several tissues, correlating it with the developmental stages of P. edulis. PeAP1 is expressed only in the reproductive stage, and it is highly expressed in tendrils and in flower meristems from the onset of their development. PeAP1 is also expressed in sepals, petals and in corona filaments, suggesting a novel role for PeAP1 in floral organ diversification. PeFUL presented a broad expression pattern in both vegetative and reproductive tissues, and it is also expressed in fruits. Conclusions Our results provide new molecular insights into the morphological diversity in the genus Passiflora. Here, we bring new evidence that tendrils are part of the Passiflora inflorescence. This points to the convergence of similar developmental processes involving the recruitment of genes related to flower identity in the origin of tendrils in different plant families. The data obtained also

  3. Genotoxic Effects of Diuron Contaminated Soil on the Root Meristem Cells of Allium sativum: A Possible Mechanism of Chromosome Damage.

    Science.gov (United States)

    Saxena, P N; Chauhan, L K S; Chandra, Saurabh; Gupta, S K

    2004-01-01

    Diuron, a persistant substituted urea herbicide, was tested in the root meristem cells of Allium sativum for the possible cytogenetic effects and to compare the sensitivity with Allium cepa. Test concentrations of diuron 22.5, 45.0, and 90.0 ppm were mixed in soil and the cloves of A. sativum were placed over diuron-contaminated soils. Root meristematic cells were sampled at 48 h to score Mitotic/Chromosomal aberrations and to analyze the effect on mitotic index (MI). Microscopic analyses revealed significant and dose-dependent induction of mitotic as well as chromosomal breaks. The frequency of mitotic aberrations was every time found much higher than that of chromosomal aberrations. Mild percentage of Micronucleated and Binucleated cells was observed, as MI also declined during the analysis. Based on the data of valence charge densities on the atoms of herbicide molecule and spectroscopic studies, a possible mechanism of interaction of diuron with DNA molecule for chromosomal aberrations has been proposed.

  4. Response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings exposed to UV-B.

    Science.gov (United States)

    Chen, Yi-Ping

    2009-07-01

    To determine the response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings, Isatis indigotica seedlings were subjected to UV-B radiation (10.08 kJ m(-2)) for 8 h day(-1) for 8 days (PAR, 220 micromol m(-2) s(-1)) and then exposed to He-Ne laser radiation (633 nm; 5.23 mW mm(-2); beam diameter: 1.5 mm) for 5 min each day without ambient light radiation. Changes in free radical elimination systems were measured, the results indicate that: (1) UV-B radiation enhanced the concentration of Malondialdahyde (MDA) and decreased the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in seedlings compared with the control. The concentration of MDA was decreased and the activities of SOD, CAT and POD were increased when seedlings were subjected to elevated UV-B damage followed by laser; (2) the concentration of UV absorbing compounds and proline were increased progressively with UV-B irradiation, laser irradiation and He-Ne laser irradiation plus UV-B irradiation compared with the control. These results suggest that laser radiation has an active function in repairing UV-B-induced lesions in seedlings.

  5. Transcriptomics insights into the genetic regulation of root apical meristem exhaustion and determinate primary root growth in Pachycereus pringlei (Cactaceae).

    Science.gov (United States)

    Rodriguez-Alonso, Gustavo; Matvienko, Marta; López-Valle, Mayra L; Lázaro-Mixteco, Pedro E; Napsucialy-Mendivil, Selene; Dubrovsky, Joseph G; Shishkova, Svetlana

    2018-06-04

    Many Cactaceae species exhibit determinate growth of the primary root as a consequence of root apical meristem (RAM) exhaustion. The genetic regulation of this growth pattern is unknown. Here, we de novo assembled and annotated the root apex transcriptome of the Pachycereus pringlei primary root at three developmental stages, with active or exhausted RAM. The assembled transcriptome is robust and comprehensive, and was used to infer a transcriptional regulatory network of the primary root apex. Putative orthologues of Arabidopsis regulators of RAM maintenance, as well as putative lineage-specific transcripts were identified. The transcriptome revealed putative orthologues of most proteins involved in housekeeping processes, hormone signalling, and metabolic pathways. Our results suggest that specific transcriptional programs operate in the root apex at specific developmental time points. Moreover, the transcriptional state of the P. pringlei root apex as the RAM becomes exhausted is comparable to the transcriptional state of cells from the meristematic, elongation, and differentiation zones of Arabidopsis roots along the root axis. We suggest that the transcriptional program underlying the drought stress response is induced during Cactaceae root development, and that lineage-specific transcripts could contribute to RAM exhaustion in Cactaceae.

  6. Identity and Professional Networking.

    Science.gov (United States)

    Raj, Medha; Fast, Nathanael J; Fisher, Oliver

    2017-06-01

    Despite evidence that large professional networks afford a host of financial and professional benefits, people vary in how motivated they are to build such networks. To help explain this variance, the present article moves beyond a rational self-interest account to examine the possibility that identity shapes individuals' intentions to network. Study 1 established a positive association between viewing professional networking as identity-congruent and the tendency to prioritize strengthening and expanding one's professional network. Study 2 revealed that manipulating the salience of the self affects networking intentions, but only among those high in networking identity-congruence. Study 3 further established causality by experimentally manipulating identity-congruence to increase networking intentions. Study 4 examined whether identity or self-interest is a better predictor of networking intentions, providing support for the former. These findings indicate that identity influences the networks people develop. Implications for research on the self, identity-based motivation, and professional networking are discussed.

  7. 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...

  8. 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.

  9. 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…

  10. 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…

  11. 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.

  12. 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 ...

  13. 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

  14. 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

  15. 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...

  16. Evaluation of Different Levels of Nitrogen and Phosphorus Fertilizers on Shoot and Root Characteristics of Echinacea purpurea

    Directory of Open Access Journals (Sweden)

    morteza Goldani

    2017-09-01

    to the soil before planting and one month after transplanting seedlings and phosphorus fertilizer was added to the soil after transplanting. Results and Discussion: A difference in plant height at different levels of nitrogen was significant. By increasing the amount of nitrogen to 1 gr, plant height from 69.44 increased to 81.11 cm. Number of lateral shoots wasn’t significant in any levels of nitrogen and phosphorus. Increasing of nitrogen from 0 to 2 grams per kg of soil increased leaf weight from 2.4 to 7.5 g. However, with increasing levels of phosphorus, weight and leaf area increased. So that the treatment without phosphorus, dry weight was 4.37 grams and in 1.5 grams of phosphorus was the highest leaf dry weight with 5.77 gr. With increasing levels of nitrogen from 0 to 1 gram, shoot dry weight increased and with increasing nitrogen from 1 to 2 grams of weight shoot dry weight was low. Treatment with 1 gr of nitrogen per kilogram of soil had the highest stem dry weight per plant with 8.7 grams and showed significant differences with other treatment. Based on the results, the effect of nitrogen fertilizer treatments in the number of flowers and flower dry weight was significant at 1%, the effect of phosphorus on flower dry weight was significant. But the interaction of nitrogen and phosphorus fertilizer treatments in any levels was not significant. The highest SPAD index in1.5 gr of phosphorus and lowest (53.74 in the treatment without phosphorus was observed. Different levels of nitrogen fertilizer had not significant effect on the length and diameter of the root but a significant effect of phosphorus on root length was showed. It seems nitrogen in 1 gr per kg is related to increase photosynthesis and the growth of organs. Nitrogen with increasing in meristem cell division can increase vegetative growth and plant size. Zeinali et al (1387 reported that phosphorus can increase carbohydrates and mineral combinations in the shoots, flowers and roots. As a

  17. Exploring medical identity theft.

    Science.gov (United States)

    Mancilla, Desla; Moczygemba, Jackie

    2009-09-16

    The crime of medical identity theft is a growing concern in healthcare institutions. A mixed-method study design including a two-stage electronic survey, telephone survey follow-up, and on-site observations was used to evaluate current practices in admitting and registration departments to reduce the occurrence of medical identity theft. Survey participants were chief compliance officers in acute healthcare organizations and members of the Health Care Compliance Association. Study results indicate variance in whether or how patient identity is confirmed in healthcare settings. The findings of this study suggest that information systems need to be designed for more efficient identity management. Admitting and registration staff must be trained, and compliance with medical identity theft policies and procedures must be monitored. Finally, biometric identity management solutions should be considered for stronger patient identification verification.

  18. Experiencing with Identity

    DEFF Research Database (Denmark)

    Pors, Justine Grønbæk

    2012-01-01

    This article studies how a political organization begins to experiment with its identity. By use of an empirical case of the Danish Ministry of Education, I examine how a political organization supplements its identity of a legislating power with identities of a supervisor, beacon and facilitator...... of evaluation in public schools. Out of a paralysis emerge new innovative strategies of governing, aimed at the schools’ self-governing capacity. The identity of the political system thus emerges as oscillations between different roles of a legislating power and a supervising coach. The case study suggests...... that a society of experimentalism is emerging. Thus, the relevant object of study is no longer organizational identity, but the experiments with different identities that modern organizations are performing....

  19. 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.

  20. 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.

  1. 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)

  2. Professional entrepreneurial identity construction

    DEFF Research Database (Denmark)

    Ramsgaard, Michael Breum

    The present study investigates the construction of a professional identity as an entrepreneur in a sample of people with educational background in nutrition and health. The study examines the connection between professional identity construction and entrepreneurial business emergence using...... ‘entrepreneurial preparedness’ as parameter. This research seeks to address the following questions: What significant components or characteristics do entrepreneurs rely on in the early processes of constructing an entrepreneurial identity....

  3. Personal Identity in Enhancement

    Directory of Open Access Journals (Sweden)

    Jana Podroužková

    2015-09-01

    Full Text Available The aim of this paper is to introduce the concept of human enhancement, its methods and its relation to personal identity. Also several approaches to personal identity will be described. Transhumanism is a special think tank supporting human enhancement through modern technologies and some of its representatives claim, that even great changes to human organisms will not affect their personal identity. I will briefly describe the most important means of human enhancment and consider the problem of personal identity for each of them separately.

  4. Known and Unknown Identity

    DEFF Research Database (Denmark)

    Henze-Pedersen, Sofie

    This qualitative study investigates the relationship between openness and identity among 18 adoptees. Many studies have argued that a high degree of openness is important for the identity formation of adoptees. However, few studies have explored this relationship. Two types of openness...... (biographical knowledge and communicative openness) are used to categorise the empirical material, making it possible to illuminate how different types of openness influence identity. The findings suggest that there is no direct link between a high degree of openness and positive identity formation. Instead...

  5. Identity/Time

    Directory of Open Access Journals (Sweden)

    Nancy J. Knauer

    2013-09-01

    Full Text Available This paper engages the unspoken fourth dimension of intersectionality—time. Using the construction of lesbian, gay, bisexual, and transgender (LGBT identities as an example, it establishes that identity, as it is lived and experienced, is not only multivalent, but also historically contingent. It then raises a number of points regarding the temporal locality of identity—the influence of time on issues of identity and understanding, its implications for legal interventions, social movement building, and paradigms of progressive change. As the title suggests, the paper asks us to consider the frame of identity over time.

  6. 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)

  7. 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.

  8. A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis

    Science.gov (United States)

    Lee, Chunghee; Clark, Steven E.

    2015-01-01

    The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified. PMID:26011610

  9. Elective Identities, (Culture, Identization and Integration)

    NARCIS (Netherlands)

    S.J. Magala (Slawomir)

    2002-01-01

    textabstractMost of contemporary individual and social identities (constructed with societal, cultural and technological resources) are radically autonomous, nomadic and virtual - i.e. they are de-traditionalized, open to negotiation and not based on a single interpretation of a tradition.

  10. 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

  11. (Re)scaling identities

    DEFF Research Database (Denmark)

    Koefoed, Lasse Martin; Simonsen, Kirsten

    2012-01-01

    of Pakistani origin, the study employs theoretical ideas of estrangement, identification and recognition in order to obtain a thorough understanding of the complexity and the contradictory character of their spatial identities and affiliations. A turning point in the double processes of estrangement...... of identity....

  12. Value Conditionality of Identity

    Directory of Open Access Journals (Sweden)

    M M Yusupov

    2013-12-01

    Full Text Available The article considers theoretical approaches to the study of values and identity, and reveals the role of values in the formation of the ethnic, regional and Russian identity on the example of Chechnya and the North Caucasus, with the sociological indicators characterizing value orientations and self-identification.

  13. Self and social identity

    NARCIS (Netherlands)

    Ellemers, N; Spears, R; Doosje, B

    2002-01-01

    In this chapter, we examine the self and identity by considering the different conditions under which these are affected by the groups to which people belong. From a social identity perspective we argue that group commitment, on the one hand, and features of the social context, on the other hand,

  14. Children's Social Identities

    Science.gov (United States)

    Bennett, Mark

    2011-01-01

    This paper provides a brief overview of recent developmental research on themes related to children's social identities. Initially, consideration is given to the capacity for social categorization, following which attention is given to children's developing conceptions of social identities, their identification with social groups, and the…

  15. Corporate identity. Brand designs.

    Science.gov (United States)

    Mathieson, Steve

    2004-02-19

    The past two years have seen a steadily more consistent brand identity for the NHS. Branding will become more important as foundation status and PCT commissioning makes acute hospitals more competitive. This has put pressure on some trusts that have their own strong identities.

  16. Identities-in-action

    DEFF Research Database (Denmark)

    Stentoft, Diana; Valero, Paola

    2009-01-01

    The notion of identity is often used in mathematics education research in an attempt to link individual and social understandings of mathematical learning. In this paper we review existing research making use of the notion of identity, and we point to some of the strengths and weaknesses in the w...

  17. Identity without Membership?

    DEFF Research Database (Denmark)

    Dobusch, Leonhard; Schoeneborn, Dennis

    the formation of organizational identity in more fluid organizational settings. Drawing on an empirical study of the hacker collective Anonymous, we show that organizational identity is formed through public communicative events that are subject to meaning negotiation whether or not actions can be attributed...

  18. Personal Identity in Japan

    Science.gov (United States)

    Sugimura, Kazumi; Mizokami, Shinichi

    2012-01-01

    This chapter explores characteristics of identity formation among Japanese adolescents and young adults living in a cultural context where individualism has been increasingly emphasized even while maintaining collectivism. We argue that, to develop a sense of identity in Japanese culture, adolescents and young adults carefully consider others'…

  19. Establecimiento y multiplicación in vitro de mora de castilla (Rubus glaucus Benth. variedad sin espinas, mediante ápices meristemáticos

    Directory of Open Access Journals (Sweden)

    Alina Katil Sigarroa-Rieche

    2011-12-01

    Full Text Available Se evaluó una técnica de micropropagación de plantas de mora (Rubus glaucus de la variedad sin espinas, a partir de ápices meristemáticos. En la fase de establecimiento se evaluó un protocolo de desinfección utilizando por 5 min solución de jabón detergente comercial y agua + alcohol 70% por 2 min + hipoclorito 3% con dos tiempos de exposición diferentes: T1 por 5 min y T2 por 10 min. Después de desinfectar las microestacas se extrajeron los ápices meristemáticos y se establecieron in vitro bajo un diseño completamente al azar para evaluar dos medios de cultivo: M1 y M2. A partir de las plántulas desarrolladas se efectuó la multiplicación en los medios de cultivo M1, M3 y M4. Ambos tratamientos de desinfección resultaron efectivos alcanzando 100% de desinfección de los explantes con cada uno de ellos. La siembra de ápices meristemáticos permitió el establecimiento de cultivos asépticos y un adecuado desarrollo de los explantes después de seis semanas de cultivo, con prendimiento de 83.4% para M1 y 66.6% para M2. El análisis de varianza (Anova y la prueba de rangos múltiples mostraron que la multiplicación fue mejor en el medio M1 con una mayor tasa de crecimiento y desarrollo del explante, al obtener coeficientes de multiplicación de 7.5 brotes/plántula y una altura promedio de 1.95 cm.

  20. Establecimiento y multiplicación in vitro de mora de castilla (Rubus glaucus Benth. variedad sin espinas, mediante ápices meristemáticos

    Directory of Open Access Journals (Sweden)

    Sigarroa Rieche Alina Katil

    2011-12-01

    Full Text Available Se evaluó una técnica de micropropagación de plantas de mora (Rubus glaucus de la variedad sin espinas, a partir de ápices meristemáticos. En la fase de establecimiento se evaluó un protocolo de desinfección utilizando por 5 min solución de jabón detergente comercial y agua + alcohol 70% por 2 min + hipoclorito 3% con dos tiempos de exposición diferentes: T1 por 5 min y T2 por 10 min. Después de desinfectar las microestacas se extrajeron los ápices meristemáticos y se establecieron in vitro bajo un diseño completamente al azar para evaluar dos medios de cultivo: M1 y M2. A partir de las plántulas desarrolladas se efectuó la multiplicación en los medios de cultivo M1, M3 y M4. Ambos tratamientos de desinfección resultaron efectivos alcanzando 100% de desinfección de los explantes con cada uno de ellos. La siembra de ápices meristemáticos permitió el establecimiento de cultivos asépticos y un adecuado desarrollo de los explantes después de seis semanas de cultivo, con prendimiento de 83.4% para M1 y 66.6% para M2. El análisis de varianza (Anova y la prueba de rangos múltiples mostraron que la multiplicación fue mejor en el medio M1 con una mayor tasa de crecimiento y desarrollo del explante, al obtener coeficientes de multiplicación de 7.5 brotes/plántula y una altura promedio de 1.95 cm.

  1. 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)

  2. Multicultural identity processes.

    Science.gov (United States)

    Hong, Ying-Yi; Zhan, Siran; Morris, Michael W; Benet-Martínez, Verónica

    2016-04-01

    The study of multicultural identity has gained prominence in recent decades and will be even more urgent as the mobility of individuals and social groups becomes the 'new normal'. This paper reviews the state-of-the-art theoretical advancements and empirical discoveries of multicultural identity processes at the intrapersonal, interpersonal, and collective (e.g., organizational, societal) levels. First, biculturalism has more benefits for individuals' psychological and sociocultural adjustment than monoculturalism. Bicultural individuals' racial essentialist beliefs and Bicultural Identity Integration affect cultural frame switching, racial categorization, and creativity. Second, identity denial and identity-based discrimination by other people or groups threaten multicultural individuals' psychological health and performance. Third, multiculturalism and interculturalism policies are associated with different conceptions of and attitudes toward diversity, and have distinct outcomes for multicultural individuals and societies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Identity as wrapping up

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2015-01-01

    The aim of this paper is to provide an understanding of cross-professional collaboration and to develop a notion of professional identity based in practice. The background of the paper is science and technology studies and more precisely actor network theory. The method used: The empirical analysis...... in close relation to the making of a report concerning the cross-professional collaboration. Findings are that “Identity as wrapping up” points to the way in which certain actors, by other actors, are maneuvered into certain pockets in a network. Identity as wrapping up is emphasized as a way...... of participating, which is closely connected to the intention to control the relation towards the other. Thus identity as wrapping up is argued to be a strategy to optimize the situation of one’s own profession. Conclusion: This articulation of identity contributes to the actor network literature as well...

  4. Researcher Identity in Transition

    DEFF Research Database (Denmark)

    Castelló, Montserrat; Kobayashi, Sofie; McGinn, Michelle K.

    2015-01-01

    to reinterpretation, and ECRs need to attend to new or reimagined signals in their efforts to develop a researcher identity in this current context. In this article, we present a comprehensive framework for researcher identity in relation to the ways ECRs recognise and respond to divergent signals across spheres...... of activity. We illustrate this framework through eight identity stories drawn from our earlier research projects. Each identity story highlights the congruence (or lack of congruence) between signals across spheres of activity and emphasises the different ways ECRs respond to these signals. The proposed...... comprehensive framework allows for the analysis of researcher identity development through the complex and intertwined activities in which ECRs are involved. We advance this approach as a foundation for a sustained research agenda to understand how ECRs identify and respond to relevant signals, and...

  5. Visual identity and rebranding

    Directory of Open Access Journals (Sweden)

    Katarzyna Wrona

    2015-06-01

    Full Text Available The goal of this article is to highlight the essence of visual identification and rebranding, as well as to discuss elements of corporate identity, which are subject to revitalization in the process of refreshing the image of a brand. In the first part the article the analysis of the term visual identification is conducted. In the analysis special attention is drawn to the role of visual identification in creating a coherent identity of an organization. In the subsequent chapters further components of corporate identity are presented in detail – starting with logotype, through business forms, advertisements, accompanying materials and Internet websites to signs on buildings. Moreover, corporate identity book as a collection of standards and guidelines for application of corporate identity rules is discussed. The deliberations are based on the study of literature. The last chapter presented the transformation of the brand of Institute of Aviation.

  6. Differential spatial expression of A- and B-type CDKs, and distribution of auxins and cytokinins in the open transverse root apical meristem of Cucurbita maxima.

    Science.gov (United States)

    Chiappetta, Adriana; Bruno, Leonardo; Salimonti, Amelia; Muto, Antonella; Jones, Jessica; Rogers, Hilary J; Francis, Dennis; Bitonti, Maria Beatrice

    2011-05-01

    Aside from those on Arabidopsis, very few studies have focused on spatial expression of cyclin-dependent kinases (CDKs) in root apical meristems (RAMs), and, indeed, none has been undertaken for open meristems. The extent of interfacing between cell cycle genes and plant growth regulators is also an increasingly important issue in plant cell cycle studies. Here spatial expression/localization of an A-type and B-type CDK, auxin and cytokinins are reported in relation to the hitherto unexplored anatomy of RAMs of Cucurbita maxima. Median longitudinal sections were cut from 1-cm-long primary root tips of C. maxima. Full-length A-type CDKs and a B-type CDK were cloned from C. maxima using degenerate primers, probes of which were localized on sections of RAMs using in situ hybridization. Isopentenyladenine (iPA), trans-zeatin (t-Z) and indole-3yl-acetic acid (IAA) were identified on sections by immunolocalization. The C. cucurbita RAM conformed to an open transverse (OT) meristem typified by an absence of a clear boundary between the eumeristem and root cap columella, but with a distinctive longitudinally thickened epidermis. Cucma;CDKA;1 expression was detected strongly in the longitudinally thickened epidermis, a tissue with mitotic competence that contributes cells radially to the root cap of OT meristems. Cucma;CDKB2 was expressed mainly in proliferative regions of the RAM and in lateral root primordia. iPA and t-Z were mainly distributed in differentiated cells whilst IAA was distributed more uniformly in all tissues of the RAM. Cucma;CDKA;1 was expressed most strongly in cells that have proliferative competence whereas Cucma;CDKB2 was confined mainly to mitotic cells. iPA and t-Z marked differentiated cells in the RAM, consistent with the known effect of cytokinins in promoting differentiation in root systems. iPA/t-Z were distributed in a converse pattern to Cucma;CDKB2 expression whereas IAA was detected in most cells in the RAM regardless of their proliferative

  7. Uprooting an abscisic acid paradigm: Shoots are the primary source.

    Science.gov (United States)

    McAdam, Scott A M; Manzi, Matías; Ross, John J; Brodribb, Timothy J; Gómez-Cadenas, Aurelio

    2016-06-02

    In the past, a conventional wisdom has been that abscisic acid (ABA) is a xylem-transported hormone that is synthesized in the roots, while acting in the shoot to close stomata in response to a decrease in plant water status. Now, however, evidence from two studies, which we have conducted independently, challenges this root-sourced ABA paradigm. We show that foliage-derived ABA has a major influence over root development and that leaves are the predominant location for ABA biosynthesis during drought stress.

  8. Linguistic identity matching

    CERN Document Server

    Lisbach, Bertrand

    2013-01-01

    Regulation, risk awareness and technological advances are increasingly drawing identity search functionality into business, security and data management processes, as well as fraud investigations and counter-terrorist measures.Over the years, a number of techniques have been developed for searching identity data, traditionally focusing on logical algorithms. These techniques often failed to take into account the complexities of language and culture that provide the rich variations  seen in names used around the world. A new paradigm has now emerged for understanding the way that identity data

  9. Vocational Identity and Ego Identity Status in Korean Nursing Students

    Directory of Open Access Journals (Sweden)

    Hyun-Young Koo, PhD, RN

    2016-03-01

    Conclusions: These findings show that nursing students in identity achievement status have secure and clear vocational identities. Further longitudinal and qualitative studies are needed to find out if identity formation among nursing students changes with age.

  10. 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)

  11. Zastosowanie peptonu Peptobak-Bacutil tu hodowli merystematycznej tkanki Cymbidium Sw. [Application of the peptone Peptobak-Bacutil medium in the culture of meristem-tissue of Cymbidium Sw.

    Directory of Open Access Journals (Sweden)

    K. Kukułczanka

    2015-06-01

    Full Text Available In was found that peptone of Peptobak-Bacutil brand (produced in Poland fulfills perfectly the requirements in cultures in vitro of the meristem tissues of Cymbidium in the modified Tsuchiya's medium in a concentration of 2 g per 1. A decrease in the concentration to 1 g per 1. affects the growth intensity of the tissue, but an increase of concentration up to 3 g per 1. retards the transformation of protocorms into the plant-stage. Growth of the meristem tissue of Cymbidium in the medium consolidated with agar is weaker and the number of protocorms produced 2,3 times lower than in liquid media.

  12. Screening for sweet potato (Ipomoea batatas (L.)) viruses and their elimination using thermotheraphy-meristem tip culture technique

    International Nuclear Information System (INIS)

    Arkorful, E.

    2012-11-01

    Despite its high potential for food security, production of sweet potato is constrained by viruses which reduce yield by 90%. It is therefore essential to screen for, identify and eliminate these viruses in elite clones before dissemination to farmers. In this study, visual symptomatology and PCR-based techniques were used to identify sweet potato viruses. Visual symptomatology revealed virus associated symptoms ranging from vein clearing, interveinal chlorosis, chlorotic spots, upward curling on leaf edges, leaf narrowing and distortion, purpling, blistering, reduction of the leaf blades and general leaf yellowing in all 22 accessions grown on the field. Disease Incidence (DI) significantly (p≤0.05) varied between accessions with US003 having the lowest (20%) while ten accessions had 90% DI at the end of the study. Index of symptom severity of all plants (ISSap) ranged from 1.08±0.09 to 3.67 ±0.11 with VOTCR003 having the lowest suggesting that it is a moderately susceptible accession while VOTCR002 had the highest suggesting that it is susceptible to viral diseases. Contrarily, index of symptom severity of diseased plants (ISSdp) ranged from 2.00±0.25 to 3.75±0.32. The accession VOTCR002 had the highest ISSdp. Visual symptomatology showed that VOTCR002 had the highest DI, ISSap and ISSdp suggesting that it is highly susceptible to viral diseases. Ten severely infected accessions were tested for Sweet Potato leaf curl virus (SPLCV), Sweet Potato chlorotic stunt virus (SPCSV), Sweet potato feathery mottle virus (SPFMV) and Sweet Potato mild mottle virus (SPMMV) using PCR and RT-PCR techniques. RT-PCR did not amplify any of the virus genomes due to prolonged storage enzymes, In contrast, PCR detected SPLCV in 30% of the accessions. Plants infected with SPLCV were grown in the chamber at 35 degrees celsius for 4 weeks followed by meristem top culture. The regenerants were indexed after ten weeks for SPLCV. Fifty two percent (52.385 od the regenerants were

  13. Seasonal variation in secondary metabolites of edible shoots of Buck's beard [Aruncus dioicus (Walter) Fernald (Rosaceae)].

    Science.gov (United States)

    Fusani, Pietro; Piwowarski, Jakub P; Zidorn, Christian; Kiss, Anna K; Scartezzini, Fabrizio; Granica, Sebastian

    2016-07-01

    Aruncus dioicus (Walter) Fernald is an herbaceous plant belonging to the Rosaceae family. In the northern regions of Italy young shoots of A. dioicus are collected and used as vegetable. No studies on the chemical composition of young shoots of A. dioicus have been reported so far. Thus, the aim of the present paper was to develop and validate a comprehensive chromatographic method allowing the identification and quantification of chemical compounds occurring in A. dioicus shoots harvested at different developmental stages. The results showed that shoots contain mainly polyphenols. Twenty-four compounds were detected. Caffeoylglucose derivatives were recognized as major compounds. It was also confirmed that shoots contain the cyanogenic compound prunasin at all investigated vegetation stages. It was shown that the prunasin content significantly increases during plant development, thus justifying the belief that after the development of the first green leaves, shoots should not be used for culinary purposes any longer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  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. Personal Identity Online

    DEFF Research Database (Denmark)

    Rodogno, Raffaele

    2012-01-01

    Philosophers concerned with the question of personal identity have typically been asking the so-called re-identification question: what are the conditions under which a person at one point in time is properly re-identified at another point in time? This is a rather technical question. In our...... everyday interactions, however, we do raise a number of personal identity questions that are quite distinct from it. In order to explore the variety of ways in which the Internet may affect personal identity, I propose in this study to broaden the typical philosophical horizon to other more mundane senses...... of the question. In Section 2, I describe a number of possible meanings of personal identity observed in everyday contexts and more philosophical ones. With some caveats, I argue that it is the specific context in which the question arises that disambiguates the meaning of the question. Online contexts are novel...

  16. Researcher Identities in Transition

    DEFF Research Database (Denmark)

    Castelló, Montserrat; Wisker, Gina; Kobayashi, Sofie

    as other emergent ‘signals’, the latent or clear indications from institutions and academic communities regarding career directions and necessary professional skills and attitudes should be identified and interpreted for researchers to adequately develop their new identities. The aim of this paper......Researchers are now embarked upon what we define as a ‘risk career’, rather than, as previously, a relatively more predictable academic career. In this changing context, traditional milestones that enabled early career researchers to build their identities are disappearing. Instead, what we define...... is twofold: a) to present a comprehensive framework of the notion of researcher identity by means of analysing those spheres of activity related to researcher and career development; and b) to relate researcher identities to the experiences of early career researchers with issues concerning signals...

  17. Primary Identity in Literature

    DEFF Research Database (Denmark)

    Graham, Brian Russell

    In our times, literary criticism, as well as larger political and cultural developments, is characterized by identity politics, meaning that our discourses are structured around the notion of different socially identifiable populations in society. In relation to literature, this results in our...... viewing the characters in literature in terms of these political identities. Literature is consequently discussed in relation to political causes. Literary criticism is animated by the same causes, and is viewed as having a direct intervention in society in relation to them. In this paper, I will discuss......, in relation to Frye’s works, the idea that the primary identities of characters in literature were and, to a considerable extent, continue to be those of family-member identities. As such, literature should not be appropriated to a political context too readily. Whereas viewing characters in terms of...

  18. Music, culture and identity

    Directory of Open Access Journals (Sweden)

    Ilir Ramadani

    2017-03-01

    Full Text Available At the time of globalization it is difficult to pretend avoiding music culture and identity from political, cultural and social developments. Thus, it is impossible for the music to be unshakable and to represent national identity by not taking and giving nothing to culture. The dynamics of life and the rapid development of technology make it impossible for the culture to remain unaffected in terms of sharing experiences social experiences. Culture represents our current course, both in terms of politics, also in the social and human aspects. Through the technology it is possible for our children to be equal with children of all other countries, to exchange information and to connect directly with all countries of the world. Musical education is one of the main factors of cultural development and preservation of national identity. Identity consists of everything we posses and reflect. We are those who distinguish from each other and have a common denominator compared to other nations.

  19. 3D analysis of mitosis distribution highlights the longitudinal zonation and diarch symmetry in proliferation activity of the Arabidopsis thaliana root meristem.

    Science.gov (United States)

    Lavrekha, Viktoriya V; Pasternak, Taras; Ivanov, Victor B; Palme, Klaus; Mironova, Victoria V

    2017-12-01

    To date CYCB1;1 marker and cortex cell lengths have been conventionally used to determine the proliferation activity of the Arabidopsis root meristem. By creating a 3D map of mitosis distribution we showed that these markers overlooked that stele and endodermis save their potency to divide longer than the cortex and epidermis. Cessation of cell divisions is not a random process, so that mitotic activity within the endodermis and stele shows a diarch pattern. Mitotic activity of all root tissues peaked at the same distance from the quiescent center (QC); however, different tissues stopped dividing at different distances, with cells of the protophloem exiting the cell cycle first and the procambial cells being the last. The robust profile of mitotic activity in the root tip defines the longitudinal zonation in the meristem with the proliferation domain, where all cells are able to divide; and the transition domain, where the cell files cease to divide. 3D analysis of cytokinin deficient and cytokinin signaling mutants showed that their proliferation domain is similar to that of the wild type, but the transition domain is much longer. Our data suggest a strong inhibitory effect of cytokinin on anticlinal cell divisions in the stele. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  20. Caffeine-Induced Premature Chromosome Condensation Results in the Apoptosis-Like Programmed Cell Death in Root Meristems of Vicia faba.

    Directory of Open Access Journals (Sweden)

    Dorota Rybaczek

    Full Text Available We have demonstrated that the activation of apoptosis-like programmed cell death (AL-PCD was a secondary result of caffeine (CF induced premature chromosome condensation (PCC in hydroxyurea-synchronized Vicia faba root meristem cells. Initiation of the apoptotic-like cell degradation pathway seemed to be the result of DNA damage generated by treatment with hydroxyurea (HU [double-stranded breaks (DSBs mostly] and co-treatment with HU/CF [single-stranded breaks (SSBs mainly]. A single chromosome comet assay was successfully used to study different types of DNA damage (neutral variant-DSBs versus alkaline-DSBs or SSBs. The immunocytochemical detection of H2AXS139Ph and PARP-2 were used as markers for DSBs and SSBs, respectively. Acridine orange and ethidium bromide (AO/EB were applied for quantitative immunofluorescence measurements of dead, dying and living cells. Apoptotic-type DNA fragmentation and positive TUNEL reaction finally proved that CF triggers AL-PCD in stressed V. faba root meristem cells. In addition, the results obtained under transmission electron microscopy (TEM further revealed apoptotic-like features at the ultrastructural level of PCC-type cells: (i extensive vacuolization; (ii abnormal chromatin condensation, its marginalization and concomitant degradation; (iii formation of autophagy-like vesicles (iv protoplast shrinkage (v fragmentation of cell nuclei and (vi extensive degeneration of the cells. The results obtained have been discussed with respect to the vacuolar/autolytic type of plant-specific AL-PCD.

  1. WORK AND LEARNER IDENTITY

    DEFF Research Database (Denmark)

    Kondrup, Sissel

    2015-01-01

    The aim of this article is to suggest a theoretical framework than can assess to how people’s engagement in specific historical and social work practices are significant to their development, maintenance or transformation of a learner identity. Such a framework is crucial in order to grasp how...... different groups have distinctive conditions for meeting the obligation of forming a proactive learner identity and engage in lifelong learning prevalent in both national and transnational policies on lifelong learning....

  2. Introduction: Discourses of Identity

    DEFF Research Database (Denmark)

    Madsen, Peter

    2016-01-01

    Analysis of usages of ideas of 'identity' in relation to migration in Britain, France, and Germany, as well as in the Serbian anti-muslim war - with a view of demonstrating conceptual context of the usages.......Analysis of usages of ideas of 'identity' in relation to migration in Britain, France, and Germany, as well as in the Serbian anti-muslim war - with a view of demonstrating conceptual context of the usages....

  3. Developing Identity for Lawyers

    OpenAIRE

    Høedt-Rasmussen, Inger

    2014-01-01

    The role of the lawyer is in transition and the formerly predominantly homogeneous profes-sion has become a heterogeneous group of lawyers with diverging perceptions of the lawyer’s identity and of the main characteristics of the profession. The European Union has extended the perception of democracy and the fundamental rights to include more collective rights, social concerns, global responsibility and sustainability. The dissertation’s main question is: How can the identity and competen...

  4. Shoot-derived abscisic acid promotes root growth.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J; Ross, John J

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a major role in regulating root growth. Most work to date has investigated the influence of root-sourced ABA on root growth during water stress. Here, we tested whether foliage-derived ABA could be transported to the roots, and whether this foliage-derived ABA had an influence on root growth under well-watered conditions. Using both application studies of deuterium-labelled ABA and reciprocal grafting between wild-type and ABA-biosynthetic mutant plants, we show that both ABA levels in the roots and root growth in representative angiosperms are controlled by ABA synthesized in the leaves rather than sourced from the roots. Foliage-derived ABA was found to promote root growth relative to shoot growth but to inhibit the development of lateral roots. Increased root auxin (IAA) levels in plants with ABA-deficient scions suggest that foliage-derived ABA inhibits root growth through the root growth-inhibitor IAA. These results highlight the physiological and morphological importance, beyond the control of stomata, of foliage-derived ABA. The use of foliar ABA as a signal for root growth has important implications for regulating root to shoot growth under normal conditions and suggests that leaf rather than root hydration is the main signal for regulating plant responses to moisture. © 2015 John Wiley & Sons Ltd.

  5. Genotypic diversity of root and shoot characteristics of

    Directory of Open Access Journals (Sweden)

    ali ganjali

    2009-06-01

    Full Text Available Root and shoot characteristics of chickpea (Cicer arietinum L. genotypes are believed to be important in drought tolerance. There is a little information about the response of genotypes root growth in hydroponics and greenhouse culture, also the relationships between root size and drought tolerance. This study was conducted to observe whether genotypes differ in root size, and to see that root size is associated with drought tolerance during early vegetative growth. We found significant differences (p0.01 in root dry weight, total root length, tap root length, root area, leaf dry weight, leaf area and shoot biomass per plant among 30 genotypes of chickpea grown in hydroponics culture for three weeks. Each of these parameters correlated with all others, positively. Among 30 genotypes, 10 genotypes with different root sizes were selected and were grown in a greenhouse in sand culture experiment under drought stress (FC %30 for three weeks. There were not linear or non-linear significant correlations between root characters in hydroponics and greenhouse environments. It seems that environmental factors are dominant on genetic factors in seedling stage and so, the expression of genotypics potential for root growth characteristics of genotypes are different in hydroponic and greenhouse conditions. In this study, the selection of genotypes with vigorous roots system in hydroponic condition did not lead to genotypes with the same root characters in greenhouse environment. The genotype×drought interactions for root characters of chickpea seedlings in 30 days were not significant (p

  6. Novel species of Botryosphaeriaceae associated with shoot blight of pistachio.

    Science.gov (United States)

    Chen, ShuaiFei; Li, GuoQing; Liu, FeiFei; Michailides, Themis J

    2015-01-01

    Various species of phytopathogenic Botryosphaeriaceae were identified previously from pistachio trees worldwide. Disease symptoms caused by pathogens in Botryosphaeriaceae on pistachio include panicle and shoot blight, leaf defoliation, fruit discoloration and decay. In this study species of Botryosphaeriaceae were collected from blighted pistachio shoots in Arizona, USA, and Greece. The aims of this study were to identify these Botryosphaeriaceae isolates and to test their pathogenicity to pistachio. The fungi were identified based on comparisons of DNA sequence data of the nuclear rDNA internal transcribed spacer region (ITS), a partial translation elongation factor 1-alpha gene (TEF1), a partial β-tubulin gene (TUB2) and morphological characteristics. Results indicated that some isolates collected from pistachio represent two previously undescribed species, which we described here as Lasiodiplodia americana sp. nov. from the United States and Neofusicoccum hellenicum sp. nov. from Greece. Field inoculations of L. americana and N. hellenicum on branches of four pistachio cultivars showed that both L. americana and N. hellenicum are pathogenic on pistachio. The four pistachio cultivars differed in their susceptibility to the Botryosphaeriaceae species. Results of this study suggested that the two new species of Botryosphaeriaceae need to be monitored carefully to determine the distribution of these pathogens and the possible spread to other areas. © 2015 by The Mycological Society of America.

  7. 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.

  8. Individual Alpha Peak Frequency in Ice Hockey Shooting Performance

    Directory of Open Access Journals (Sweden)

    Sommer Christie

    2017-05-01

    Full Text Available There are several important inter- and intra-individual variations in individual alpha peak frequency (IAPF in the cognitive domain. The rationale for the present study was to extend the research on IAPF in the cognitive domain to IAPF in the sport domain. Specifically, the purpose of the present study was twofold: (a to explore whether baseline IAPF is related to performance in an ice hockey shooting task and (b to explore whether a shooting task has an effect on IAPF variability. The present investigation is one of the first studies to examine links between IAPF and sport performance. Study results did not show significant changes in IAPF when comparing baseline IAPF and pre- to post-task IAPF across three performance levels. The findings support previous literature in the cognitive domain suggesting that IAPF is a stable neurophysiological marker. Future research should consider the following methodological suggestions: (a measuring IAPF during sport performance instead of at a resting state, (b changing the pre-performance resting baseline instructions to take into account sport-specific mental preparation, (c exploring an expert-novice paradigm to accentuate performance ability differences between groups (d comparing tasks with different levels of complexity, and (e analyzing the possible correlation between IAPF and performance on different days.

  9. Hyperhydricity in micropropagated carnation shoots: the role of oxidative stress.

    Science.gov (United States)

    Saher, Shady; Piqueras, Abel; Hellin, Eladio; Olmos, Enrique

    2004-01-01

    The physiology of hyperhydricity in relation to oxidative stress, mineral nutrients, antioxidant enzymes and ethylene has been studied in three micropropagated carnation cultivars under experimentally induced hyperhydricity. A marked increase in Fe content in comparison with normal tissues was observed in the hyperhydric tissues from the three cultivars. The levels of ethylene, solute leakage and malondialdehyde content were also significantly higher in the hyperhydric tissues. In relation to the time course of H(2)O(2) production measured by fluorescence quenching, a similar trend could be observed for the three cultivars, with a clear increase in the generation of hydrogen peroxide in hyperhydric tissues. The activities of all the antioxidative enzymes studied, except lipoxygenase, were higher in the hyperhydric shoots. Phenylalanine ammonia-lyase (PAL) showed a significant decrease in activity in the hyperhydric tissues in comparison with the controls for the three cultivars. Soluble guaiacol peroxidase had a strong increase in activity in hyperhydric shoots of the three cultivars. These results provide, for the first time, direct evidence of H(2)O(2) generation in hyperhydric tissues, characterize the response of the antioxidant system to an oxidative stress during hyperhydricity in carnation leaves and point to the accumulation of toxic forms of oxygen as the inducer of some of the abnormalities observed.

  10. In vitro establishment of Vasconcellea x helbornii (Badillo Badillo shoots

    Directory of Open Access Journals (Sweden)

    Mónica Jadán Guerrero

    2016-04-01

    Full Text Available Babaco [Vasconcellea x helbornii (Badillo Badillo] is a specie of commercial importance in Ecuador. The present work aimed to establish in vitro shoots of axillary buds from mother plants of babaco kept in greenhouse. Carbendazim and the biostimulant (GERMO-TB01 were applied to the plants. For the disinfection of the explants, three concentrations of Sodium Hypochlorite (1, 1.5 and 2% were evaluated during two times (5 and 10 minutes. In addition, the effect of the use of Gentamicin 50 mg l-1 and Streptomycin 25 mg l-1 in the culture medium was determined. The best results were achieved by using 1.5% Sodium Hypochlorite for 10 minutes and immersion in a solution with both antibiotics for 3 hours. A 68.5% in vitro establishment of the shoots was achieved at 21 days of culture. The results will contribute to in vitro mass propagation of this hybrid.   Key words: antibiotic mixture, babaco, disinfection, micropropagation

  11. Framing Mass Shootings: Fictional Depictions of Real-life Gun Massacres in American Cinema

    OpenAIRE

    Tryggeseid, Ane Johannessen

    2017-01-01

    This thesis examines the concept of real-life mass shootings and its depiction in American fictional cinema. The issue of mass shootings is a highly controversial subject of discussion, both within the public and political sphere, as it necessarily touches upon rigid perceptions of civil liberties – specifically those of the Second Amendment – which further permeates the field of fictional cinema. As opposed to assessing the issue of mass shootings as a product of a prevailing culture of guns...

  12. 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...

  13. Schools under fire? : school shootings and the construction of a cultural discourse of emergency

    OpenAIRE

    Braselmann, Silke

    2016-01-01

    Contrary to popular belief, rampage violence at suburban and rural schools occurred before the infamous Columbine High School shooting in April 1999. While school shootings — before Columbine gained international media attention — were treated as a local rather than a national or even international problem, they are now seen as an emergent phenomenon that has to be addressed with appropriate urgency. In this paper, I want to examine whether school shootings are in fact increasing and addre...

  14. Translocation of sorbitol and other photosynthates in golden delicious apple shoots

    International Nuclear Information System (INIS)

    Steenkamp, J.; Terblanche, J.H.; De Villiers, O.T.

    1982-01-01

    This study was undertaken to determine to what extent sorbitol and other photosynthates are translocated in Golden Delicious apple shoots. The distribution of radioactivity in the different fractions, after the leaves had been exposed to radiocarbon, was found in segment of the shoots directly below the treatment leaves. The highest 14 C activity was in the carbohydrate fraction. The results indicate that sorbitol is the principal carbohydrate transported in Golden Delicious apple shoots

  15. Comparative proteomics reveals the physiological differences between winter tender shoots and spring tender shoots of a novel tea (Camellia sinensis L.) cultivar evergrowing in winter.

    Science.gov (United States)

    Liu, Shengjie; Gao, Jiadong; Chen, Zhongjian; Qiao, Xiaoyan; Huang, Hualin; Cui, Baiyuan; Zhu, Qingfeng; Dai, Zhangyan; Wu, Hualing; Pan, Yayan; Yang, Chengwei; Liu, Jun

    2017-11-20

    A recently discovered tea [Camellia sinensis (L.) O. Kuntze] cultivar can generate tender shoots in winter. We performed comparative proteomics to analyze the differentially accumulated proteins between winter and spring tender shoots of this clonal cultivar to reveal the physiological basis of its evergrowing character during winter. We extracted proteins from the winter and spring tender shoots (newly formed two leaves and a bud) of the evergrowing tea cultivar "Dongcha11" respectively. Thirty-three differentially accumulated high-confidence proteins were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF / TOF MS). Among these, 24 proteins had increased abundance while nine showed were decreased abundance in winter tender shoots as compared with the spring tender shoots. We categorized the differentially accumulated proteins into eight critical biological processes based on protein function annotation including photosynthesis, cell structure, protein synthesis & destination, transporters, metabolism of sugars and polysaccharides, secondary metabolism, disease/defense and proteins with unknown functions. Proteins with increased abundance in winter tender shoots were mainly related to the processes of photosynthesis, cytoskeleton and protein synthesis, whereas those with decreased abundance were correlated to metabolism and the secondary metabolism of polyphenolic flavonoids. Biochemical analysis showed that the total contents of soluble sugar and amino acid were higher in winter tender shoots while tea polyphenols were lower as compared with spring tender shoots. Our study suggested that the simultaneous increase in the abundance of photosynthesis-related proteins rubisco, plastocyanin, and ATP synthase delta chain, metabolism-related proteins eIF4 and protease subunits, and the cytoskeleton-structure associated proteins phosphatidylinositol transfer protein and profilin may be because of the adaptation of the

  16. Effect of different intervals of x-ray split doses on shoot production of in vitro derived explants of Gerbera jamesonii Bolus

    Energy Technology Data Exchange (ETDEWEB)

    Walther, F; Sauer, A [Federal Research Centre for Horticultural Plant Breeding, Ahrensburg (Germany)

    1990-01-01

    Full text: Linearity between rising x-ray doses and mutation rate is limited by the simultaneously increasing radiation damage; induced chromosome aberrations eliminate valuable factor mutations. The application of fractionated doses provides the opportunity for repair of a distinct portion of damage. The dose of 30 Gy was fractionated into two identical parts. The periods for repair were 0.5 to 48 hs. The absolute and cumulative number of post-irradiation regenerated axillary shoots on 4 subsequent dates of cutoff were used as parameters to estimate radiosensitivity. From an economical point of view the interval of 4 hs between two dose fractions may be recommended for practice. (author)

  17. From gene manipulation to forest establishment: shoot cultures of woody plants can be a central tool

    Energy Technology Data Exchange (ETDEWEB)

    McCown, B.H.

    1985-05-01

    Establishing germplasm of woody plants in microculture as shoot cultures has proved to be an effective method of overcoming many of the obstacles in working with these crops. Shoot cultures eliminate the changes associated with seasonal growth cycles and phase change and put large plants into a more manageable form. Well-established shoot cultures are central to successful clonal propagation systems for forest trees as well as to genetic improvement based on the use of cellular techniques such as protoplast manipulation. The physiological basis as to why tissues from shoot cultures are so readily manipulated is not well understood.

  18. Effect of nitrogen salts on the growth of Ceratonia siliqua L. Shoot cultures

    Directory of Open Access Journals (Sweden)

    Vinterhalter Branka

    2007-01-01

    Full Text Available Effects of reduced nitrogen salt nutriton on the growth, lenticel hypertrophy and anthocyanin accumulation of carob (Ceratonia siliqua L. shoot cultures were investigated in conditions of light and darkness. Growth of shoot cultures was not significantly affected until nitrogen salts were reduced to less than ¼ of full-strength MS (Murashige and Skoog, 1962 values. Cultures in darkness were less affected and their main shoots even increased in length. Appearance of hypertrophied lenticels in light decreased, while in darkness they were absent in all treatments. Reduced nitrogen salt nutrition strongly affected anthocyanin accumulation of shoots and leaves, which greatly increased in both light and darkness. .

  19. Adaptive L1/2 Shooting Regularization Method for Survival Analysis Using Gene Expression Data

    Directory of Open Access Journals (Sweden)

    Xiao-Ying Liu

    2013-01-01

    Full Text Available A new adaptive L1/2 shooting regularization method for variable selection based on the Cox’s proportional hazards mode being proposed. This adaptive L1/2 shooting algorithm can be easily obtained by the optimization of a reweighed iterative series of L1 penalties and a shooting strategy of L1/2 penalty. Simulation results based on high dimensional artificial data show that the adaptive L1/2 shooting regularization method can be more accurate for variable selection than Lasso and adaptive Lasso methods. The results from real gene expression dataset (DLBCL also indicate that the L1/2 regularization method performs competitively.

  20. Lippia dulcis shoot cultures as a source of the sweet sesquiterpene hernandulcin.

    Science.gov (United States)

    Sauerwein, M; Flores, H E; Yamazaki, T; Shimomura, K

    1991-04-01

    The axenic shoot culture of Lippia dulcis Trev., Verbenaceae, was established on hormone-free Murashige-Skoog solid medium containing 3% sucrose. Shoots were cultured in various liquid or solid media. Woody Plant liquid medium was best for shoot multiplication, but the production of hernandulcin was relatively low. The highest hernandulcin content (2.9% dry wt) was obtained after 28 days of culture on Murashige-Skoog solid medium containing 2% sucrose. The addition of chitosan to the culture media enhanced the growth of shoots as well as the production of hernandulcin, especially with the liquid medium.

  1. Multiple vantage points on the mental health effects of mass shootings.

    Science.gov (United States)

    Shultz, James M; Thoresen, Siri; Flynn, Brian W; Muschert, Glenn W; Shaw, Jon A; Espinel, Zelde; Walter, Frank G; Gaither, Joshua B; Garcia-Barcena, Yanira; O'Keefe, Kaitlin; Cohen, Alyssa M

    2014-09-01

    The phenomenon of mass shootings has emerged over the past 50 years. A high proportion of rampage shootings have occurred in the United States, and secondarily, in European nations with otherwise low firearm homicide rates; yet, paradoxically, shooting massacres are not prominent in the Latin American nations with the highest firearm homicide rates in the world. A review of the scientific literature from 2010 to early 2014 reveals that, at the individual level, mental health effects include psychological distress and clinically significant elevations in posttraumatic stress, depression, and anxiety symptoms in relation to the degree of physical exposure and social proximity to the shooting incident. Psychological repercussions extend to the surrounding affected community. In the aftermath of the deadliest mass shooting on record, Norway has been in the vanguard of intervention research focusing on rapid delivery of psychological support and services to survivors of the "Oslo Terror." Grounded on a detailed review of the clinical literature on the mental health effects of mass shootings, this paper also incorporates wide-ranging co-author expertise to delineate: 1) the patterning of mass shootings within the international context of firearm homicides, 2) the effects of shooting rampages on children and adolescents, 3) the psychological effects for wounded victims and the emergency healthcare personnel who care for them, 4) the disaster behavioral health considerations for preparedness and response, and 5) the media "framing" of mass shooting incidents in relation to the portrayal of mental health themes.

  2. Tools for Understanding Identity

    Energy Technology Data Exchange (ETDEWEB)

    Creese, Sadie; Gibson-Robinson, Thomas; Goldsmith, Michael; Hodges, Duncan; Kim, Dee DH; Love, Oriana J.; Nurse, Jason R.; Pike, William A.; Scholtz, Jean

    2013-12-28

    Identity attribution and enrichment is critical to many aspects of law-enforcement and intelligence gathering; this identity typically spans a number of domains in the natural-world such as biographic information (factual information – e.g. names, addresses), biometric information (e.g. fingerprints) and psychological information. In addition to these natural-world projections of identity, identity elements are projected in the cyber-world. Conversely, undesirable elements may use similar techniques to target individuals for spear-phishing attacks (or worse), and potential targets or their organizations may want to determine how to minimize the attack surface exposed. Our research has been exploring the construction of a mathematical model for identity that supports such holistic identities. The model captures the ways in which an identity is constructed through a combination of data elements (e.g. a username on a forum, an address, a telephone number). Some of these elements may allow new characteristics to be inferred, hence enriching the holistic view of the identity. An example use-case would be the inference of real names from usernames, the ‘path’ created by inferring new elements of identity is highlighted in the ‘critical information’ panel. Individual attribution exercises can be understood as paths through a number of elements. Intuitively the entire realizable ‘capability’ can be modeled as a directed graph, where the elements are nodes and the inferences are represented by links connecting one or more antecedents with a conclusion. The model can be operationalized with two levels of tool support described in this paper, the first is a working prototype, the second is expected to reach prototype by July 2013: Understanding the Model The tool allows a user to easily determine, given a particular set of inferences and attributes, which elements or inferences are of most value to an investigator (or an attacker). The tool is also able to take

  3. The Process of Identity Work: Negotiating a Work Identity

    NARCIS (Netherlands)

    Crafford, A.; Adams, B.G.; Saayman, T.; Vinkenburg, C.J.; Jansen, P.G.W.; Roodt, G.

    2015-01-01

    Identity work is an important process in negotiating, regulating and maintaining a coherent sense of self-(identity). In this chapter we discuss how identity work is particularly useful in establishing a work identity. The crux of the discussion in this chapter is based on the qualitative phase of

  4. A School Experiment in Kinematics: Shooting from a Ballistic Cart

    Science.gov (United States)

    Kranjc, T.; Razpet, N.

    2011-10-01

    Many physics textbooks start with kinematics. In the lab, students observe the motions, describe and make predictions, and get acquainted with basic kinematics quantities and their meaning. Then they can perform calculations and compare the results with experimental findings. In this paper we describe an experiment that is not often done, but is interesting and attractive to students—the ballistic cart, i.e., the shooting of a ball from a cart moving along a slope. For that, one has to be familiar with one-dimensional uniform motion and one-dimensional motion with constant acceleration, as well as curvilinear motion that is a combination of such motions.1,2 The experimental results confirm theoretical predictions.

  5. 2D flight shooting game design and implementation

    Institute of Scientific and Technical Information of China (English)

    Luo Yunqing

    2016-01-01

    The game, which is already one of the most popular entertainment, brings us a lot of fun.A lot of big games are great (plot, graphics, sound effects, etc.), but it takes time. So a simple, playable game is also very popular.This game is in Windows 7, with Visual Studio 2013 as the editor, in c + + as the scripting language, and a flying shooter game designed by the Unity3D game engine. Mainly implements a simple flight shooting, recruit, UI text display function, but not too much pains in the interface and the picture and sound effects, can realize the basic function of the game, and game for hardware requirement is not high also, entertainment and games also is beter. It's a casual game that is simple and fun to play, and it's a great way to bring happiness to people.

  6. Manipulation of hemoglobin expression affects Arabidopsis shoot organogenesis

    DEFF Research Database (Denmark)

    Wang, Yaping; Elhiti, Mohamed; Hebelstrup, Kim

    2011-01-01

    Over the past few years non-symbiotic plant hemoglobins have been described in a variety of plant species where they fulfill several functions ranging from detoxification processes to basic aspects of plant growth and post-embryonic development. To date no information is available on the role...... of hemoglobins during invitro morphogenesis. Shoot organogenesis was induced in Arabidopsis lines constitutively expressing class 1, 2 and 3 hemoglobins (GLB1, 2 and 3) and lines in which the respective genes were either downregulated by RNAi (GLB1) or knocked out (GLB2 and GLB3). The process was executed......, 15, and 16), feed-back repressors of the cytokinin pathway, was repressed in both hemoglobin over-expressors whereas that of several Type-B ARRs (ARR2, 12, and 13), transcription activators of cytokinin-responsive genes, was induced. Such changes enhanced the sensitivity of the root explants...

  7. Identity Expansion and Transcendence

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2014-05-01

    Full Text Available Emerging developments in communications and computing technology may transform the nature of human identity, in the process rendering obsolete the traditional philosophical and scientific frameworks for understanding the nature of individuals and groups.  Progress toward an evaluation of this possibility and an appropriate conceptual basis for analyzing it may be derived from two very different but ultimately connected social movements that promote this radical change. One is the governmentally supported exploration of Converging Technologies, based in the unification of nanoscience, biology, information science and cognitive science (NBIC. The other is the Transhumanist movement, which has been criticized as excessively radical yet is primarily conducted as a dignified intellectual discussion within a new school of philosophy about human enhancement.  Together, NBIC and Transhumanism suggest the immense transformative power of today’s technologies, through which individuals may explore multiple identities by means of online avatars, semi-autonomous intelligent agents, and other identity expansions.

  8. Biometrics and Identity Management

    DEFF Research Database (Denmark)

    management. BIOID 2008. The papers are categorized in four classes. These classes represent the 4 working groups of the COST Action 2101. For more information, see http://www.cost2101.org/.   Biometric data quality and multimodal biometric templates, Unsupervised interactive interfaces for multimodal...... security and border control scenarios it is now apparent that the widespread availability of biometrics in everyday life will also spin out an ever increasing number of (private) applications in other domains. Crucial to this vision is the management of the user's identity, which does not only imply...... biometrics, Biometric attacks and countermeasures, Standards and privacy issues for biometrics in identity documents and smart cards. BIOID 2008 is an initiative of the COST Action 2101 on Biometrics for Identity Documents and Smart Cards. It is supported by the EU Framework 7 Programme. Other sponsors...

  9. Identity negotiations in meetings

    DEFF Research Database (Denmark)

    Asmuß, Birte; Oshima, Sae

    of the company, and all members know (and display) that he holds some information that the rest don’t have access to. Our analysis shows that the participants evoke various identities of the manager, sometimes orienting to the structure of the organization, and other times orienting to wider social categories......Meetings are places, where identity negotiation is a central activity and where members’ local practices recurrently inform and are informed by larger categories (Antaki and Widdicombe 1998). Correspondingly, the approach to understanding organization (macro) by way of identity work (micro) has...... company, and in the data recorded over 10 days, the employees frequently complain about the many changes that have taken place. Our focus lies in a unique occasion where one of the managers makes an unusual appearance at the lunchroom. In this situation, he is the only one that is on the business side...

  10. Learning as Negotiating Identities

    DEFF Research Database (Denmark)

    Jørgensen, Kenneth Mølbjerg; Keller, Hanne Dauer

    The paper explores the contribution of Communities of Practice (COP) to Human Resource Development (HRD). Learning as negotiating identities captures the contribution of COP to HRD. In COP the development of practice happens through negotiation of meaning. The learning process also involves modes...... of belonging constitutive of our identities. We suggest that COP makes a significant contribution by linking learning and identification. This means that learning becomes much less instrumental and much more linked to fundamental questions of being. We argue that the COP-framework links learning with the issue...... of time - caught in the notion of trajectories of learning - that integrate past, present and future. Working with the learners' notion of time is significant because it is here that new learning possibilities become visible and meaningful for individuals. Further, we argue that the concept of identity...

  11. The profile of wounding in civilian public mass shooting fatalities.

    Science.gov (United States)

    Smith, Edward Reed; Shapiro, Geoff; Sarani, Babak

    2016-07-01

    The incidence and severity of civilian public mass shootings (CPMS) continue to rise. Initiatives predicated on lessons learned from military woundings have placed strong emphasis on hemorrhage control, especially via use of tourniquets, as means to improve survival. We hypothesize that both the overall wounding pattern and the specific fatal wounds in CPMS events are different from those in military combat fatalities and thus may require a new management strategy. A retrospective study of autopsy reports for all victims involved in 12 CPMS events was performed. Civilian public mass shootings was defined using the FBI and the Congressional Research Service definition. The site of injury, probable site of fatal injury, and presence of potentially survivable injury (defined as survival if prehospital care is provided within 10 minutes and trauma center care within 60 minutes of injury) was determined independently by each author. A total 139 fatalities consisting of 371 wounds from 12 CPMS events were reviewed. All wounds were due to gunshots. Victims had an average of 2.7 gunshots. Relative to military reports, the case fatality rate was significantly higher, and incidence of potentially survivable injuries was significantly lower. Overall, 58% of victims had gunshots to the head and chest, and only 20% had extremity wounds. The probable site of fatal wounding was the head or chest in 77% of cases. Only 7% of victims had potentially survivable wounds. The most common site of potentially survivable injury was the chest (89%). No head injury was potentially survivable. There were no deaths due to exsanguination from an extremity. The overall and fatal wounding patterns following CPMS are different from those resulting from combat operations. Given that no deaths were due to extremity hemorrhage, a treatment strategy that goes beyond use of tourniquets is needed to rescue the few victims with potentially survivable injuries. Prognostic/epidemiologic study, level IV

  12. On the fundamentals of identity

    NARCIS (Netherlands)

    van der Gaag, Mandy

    Various new perspectives on identity have been introduced or have increased in popularity over the past two decades. These include identity as dynamic system (Kunnen & Bosma, 2001), a narrative approach to identity (McAdams, 2001), multi-dimensional models of identity formation (Luyckx et al., 2006;

  13. Splitting Ward identity

    Energy Technology Data Exchange (ETDEWEB)

    Safari, Mahmoud [Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-04-15

    Within the background-field framework we present a path integral derivation of the splitting Ward identity for the one-particle irreducible effective action in the presence of an infrared regulator, and make connection with earlier works on the subject. The approach is general in the sense that it does not rely on how the splitting is performed. This identity is then used to address the problem of background dependence of the effective action at an arbitrary energy scale. We next introduce the modified master equation and emphasize its role in constraining the effective action. Finally, application to general gauge theories within the geometric approach is discussed. (orig.)

  14. Social identities and risk

    DEFF Research Database (Denmark)

    Blok, Anders; Jensen, Mette; Kaltoft, Pernille

    2008-01-01

    Expert-based environmental and health risk regulation is widely believed to suffer from a lack of public understanding and legitimacy. On controversial issues such as genetically modified organisms and food-related chemicals, a "lay-expert discrepancy" in the assessment of risks is clearly visible...... of social identities. On the basis of qualitative interviews with citizens and experts, respectively, we focus on the multiple ways in which identities come to be employed in actors' risk accounts. Empirically, we identify salient characteristics of "typical" imagined experts and lay-people, while arguing...

  15. Splitting Ward identity

    International Nuclear Information System (INIS)

    Safari, Mahmoud

    2016-01-01

    Within the background-field framework we present a path integral derivation of the splitting Ward identity for the one-particle irreducible effective action in the presence of an infrared regulator, and make connection with earlier works on the subject. The approach is general in the sense that it does not rely on how the splitting is performed. This identity is then used to address the problem of background dependence of the effective action at an arbitrary energy scale. We next introduce the modified master equation and emphasize its role in constraining the effective action. Finally, application to general gauge theories within the geometric approach is discussed. (orig.)

  16. Law and Identity

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2011-01-01

    processes of social integration. Within media-based and political debates, transnational marriages are frequently described as practices destructive both to individual freedom and to Danish national identity. Nonetheless, it is a practice in which both minority and majority citizens engage, one that frames...... both their family lives and their lives as citizens. This article analyses the dynamic relationship between public discourse and practices of transnational marriage. The first part describes how political and legislative perceptions of transnational (arranged) marriages are situated within a discussion......' expressions of autonomy and choice and their adaptations of such concepts to understandings of social belonging, inclusion and identity formation vis--vis the Danish nation-state....

  17. Editorial: Negotiating Gamer Identities

    Directory of Open Access Journals (Sweden)

    Matthew Barr

    2016-07-01

    Full Text Available The term ‘gamer identity’ is hotly contested, and certainly not understood as a broadly accepted term. From the outdated stereotype of white, heterosexual, teenage boys playing Nintendo in their parents’ basement to the equally contested proclamation that “‘gamers’ are over”, the current game culture climate is such that movements as divisive and controversial as #gamergate can flourish. For this latest special issue of Press Start, we invited submissions regarding the recent controversies surrounding the notion of player identities, with the aim of receiving papers from different viewpoints on gamer identity and culture.

  18. Dose rate, mitotic cycle duration, and sensitivity of cell transitions from G1 → S and G2 → M to protracted gamma radiation in root meristems

    International Nuclear Information System (INIS)

    Evans, L.S.; Hof, J.V.

    1975-01-01

    Experiments were designed to determine the relative radiosensitivity of the cell transition points of G1 → S and G2 → M in root meristems of several plant species. Label and mitotic indices and microspectrophotometry were used to measure the proportions of cells in each mitotic cycle stage in root meristems after protracted gamma radiation. The criterion of radiosensitivity was the dose rate needed to produce a tissue with less than 1 percent cells in S and none in M after 3 days of continuous exposure. The results show that DNA is the primary radiation target in proliferative root meristems and that the cycle duration stipulates the time interval of vulnerability. In each species, nonrandom reproducible cell proportions were established with 2C:4C:8C amounts of nuclear DNA after 3 days of exposure. Roots of Helianthus annuus, Crepis capillaris, and Tradescantia clone 02 had 80 percent cells with a 2C amount of DNA and 20 percent had a 4C amount of DNA. In these species the transition point of G1 → S was more radiosensitive than G2 → M. Roots of Pisum sativum and Triticum aestivum had cell proportions at 2C:4C:8C amounts of DNA in frequencies of 0.10 to 0.20:0.40 to 0.60:0.30 to 0.40. In these two species 0.30 to 0.40 cells underwent radiation-induced endoreduplication that resulted from a rapid inhibition of cell transit from G2 → M and a slower impairment of G1 → S. Cells increased from 2C to 4C and from 4C to 8C amounts of DNA during irradiation. The proportions of nuclei with 2C:4C:8C amounts of DNA were dependent in part upon the relative radiosensitivity of the G1 → S and G2 → M control points. The data show the relative radiosensitivity of the transition points from G1 → S and from G2 → M was species specific and unrelated to the cycle duration and mean nuclear DNA content of the plant species

  19. Model Persamaan Massa Karbon Akar Pohon dan Root-Shoot Ratio Massa Karbon (Equation Models of Tree Root Carbon Mass and Root-Shoot Carbon Mass Ratio

    Directory of Open Access Journals (Sweden)

    Elias .

    2011-03-01

    Full Text Available The case study was conducted in the area of Acacia mangium plantation at BKPH Parung Panjang, KPH Bogor. The objective of the study was to formulate equation models of tree root carbon mass and root to shoot carbon mass ratio of the plantation. It was found that carbon content in the parts of tree biomass (stems, branches, twigs, leaves, and roots was different, in which the highest and the lowest carbon content was in the main stem of the tree and in the leaves, respectively. The main stem and leaves of tree accounted for 70% of tree biomass. The root-shoot ratio of root biomass to tree biomass above the ground and the root-shoot ratio of root biomass to main stem biomass was 0.1443 and 0.25771, respectively, in which 75% of tree carbon mass was in the main stem and roots of tree. It was also found that the root-shoot ratio of root carbon mass to tree carbon mass above the ground and the root-shoot ratio of root carbon mass to tree main stem carbon mass was 0.1442 and 0.2034, respectively. All allometric equation models of tree root carbon mass of A. mangium have a high goodness-of-fit as indicated by its high adjusted R2.Keywords: Acacia mangium, allometric, root-shoot ratio, biomass, carbon mass

  20. Corporate Brand Identity in SMEs

    DEFF Research Database (Denmark)

    Mäläskä, Minna; Jones, Richard Ian

    Purpose: To study the emergence of corporate brand identity in SMEs and to develop a typology of brand identity drivers that reflects a co-creative approach to the emergence of brand identity. Design / Methodology / Approach : Existing approaches to brand identity are summarised. A narrative...... studies. The research is important since it suggests an iterative and co-creative approach to brand identity. A typology of brand identity formation for SMEs is presented: entrepreneur driven, market driven, stakeholder driven. Practical implications: The three paths to creating a strong brand identity...... challenge existing notions that brand identity is based solely on the values of the entrepreneur. This typology suggests that SMEs should be open to creating an identity that draws from their stakeholder eco-system. Originality / value: this research challenges the existing assumption that brand identity...

  1. Influence of shoot topping on yield and quality of Vitis vinifera L.

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... Key words: Vitis vinifera L., shoot topping, yield, quality, canopy management, shoot topping, fruit set, yield components, fruit .... Sensory characteristics were under the interaction effect of year and topping level. Berry weight was influenced separately by the year and topping (Table 2 and 3). Yield per vine ...

  2. Unexpected Genome Variability at Multiple Loci Suggests Cacao Swollen Shoot Virus Comprises Multiple, Divergent Molecular Variants.

    Science.gov (United States)

    Cacao swollen shoot virus (CSSV) [Badnavirus, Caulimoviridae] causes swollen shoot disease of Theobroma cacao L. in West Africa. Since ~2000, various diagnostic tests have failed to detect CSSV in ~50-70% of symptomatic cacao plants, suggesting the possible emergence of new, previously uncharacteriz...

  3. 50 CFR 20.106 - Seasons, limits, and shooting hours for sandhill cranes.

    Science.gov (United States)

    2010-10-01

    ... sandhill cranes. 20.106 Section 20.106 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE..., and Shooting Hours Schedules § 20.106 Seasons, limits, and shooting hours for sandhill cranes. This section provides for the annual hunting of sandhill cranes in designated portions of the 48 contiguous...

  4. Nucleotide diversity and linkage disequilibrium in five Lolium perenne genes with putative role in shoot branching

    DEFF Research Database (Denmark)

    Brazauskas, Gintaras; Pašakinskienė, Izolda; Asp, Torben

    2010-01-01

    Knowledge on nucleotide diversity and linkage disequilibrium (LD) patterns is prerequisite for association analyses. However, little is known about the nucleotide diversity in the evolutionary important ryegrass shoot morphology genes. Five candidate genes, LpIAA1, LpRUB1, LpBRI1, LpSHOOT1 and Lp...

  5. The Nutritional Facts of Bamboo Shoots and Their Usage as Important Traditional Foods of Northeast India

    Science.gov (United States)

    Nongdam, P.; Tikendra, Leimapokpam

    2014-01-01

    Bamboo shoots are considered as one of the useful health foods because of their rich contents of proteins, carbohydrates, vitamins, fibres, and minerals and very low fat. Though bamboo shoots provide lots of health benefits, their consumption is confined mostly to Southeast Asian and East Asian countries. The acceptability of bamboo shoots as popular vegetable crop is very less due to their high pungent smell and bitter acidic taste. The use of bamboo as food in India is mainly restricted to Northeastern part of the country where they form an indispensable part of several traditional speciality dishes. The different ethnic communities take fresh or fermented bamboo shoot as one of most preferred traditional food items. Some of the important bamboo based traditional foods are ushoi, soibum, rep, mesu, eup, ekhung, hirring, and so forth. Bamboo shoots should be properly processed before they are consumed as freshly harvested shoots have high content of toxic cyanogenic glycosides which may pose serious health problems. The prospect of bamboo shoot industry in Northeast India is bright due to its rich genetic resources of bamboos. However, habitat destruction and extensive use of bamboos for food, handicraft, and construction purposes have resulted in severe depletion of natural bamboo resources. This review stresses upon the high nutritive values and health benefits of bamboo shoots and their usage as important traditional foods in Northeast India. The bamboo market potential of the region and use of in vitro plant micropropagation methods as effective means of bamboo conservation are also emphasized in this paper. PMID:27433496

  6. Developmental anatomy of blueberry (Vaccinium corymbosum L. ‘Aurora’) shoot regeneration

    Science.gov (United States)

    The culture of Vaccinium corymbosum L. ’Aurora’ leaves on regeneration medium results in the regeneration of adventitious shoots. We present anatomical evidence that these new shoot apices are directly regenerated from the cultured blades. Mounds of densely staining cells, which formed from epidermi...

  7. Shooting method for solution of boundary-layer flows with massive blowing

    Science.gov (United States)

    Liu, T.-M.; Nachtsheim, P. R.

    1973-01-01

    A modified, bidirectional shooting method is presented for solving boundary-layer equations under conditions of massive blowing. Unlike the conventional shooting method, which is unstable when the blowing rate increases, the proposed method avoids the unstable direction and is capable of solving complex boundary-layer problems involving mass and energy balance on the surface.

  8. Violent mass shootings in Sweden from 1960 to 1995: profiles, patterns, and motives.

    Science.gov (United States)

    Lindquist, O; Lidberg, L

    1998-03-01

    During the past few decades, violent mass shooting in Sweden has increased rapidly. In the 36 years between 1960 and 1995, fourteen such occasions were recorded, during which 32 people were killed and 57 were wounded. The 14 offenders were men between the ages of 17 and 61 years. In the 20 years from 1960 to 1979, five shootings were committed by five offenders, leaving 10 dead and 13 wounded; in the 16 years between 1980 and 1995, there were nine different shootings committed by nine offenders, with 22 dead and 44 wounded. Seven of the shootings were classified as mass shootings, six as spree shootings, and one as a serial shooting. In all but four of these cases, the firearms used were illegal weapons. The four legal firearms belonged to an unemployed young laborer, an officer, a former United Nations (U.N.) soldier, and a member of the Swedish military volunteer corps. Of those killed, 68.8% were strangers to the offender; among the wounded, the corresponding figure was 89.5%. Profiles of the offenders and of the victims were studied. The psychiatric diagnoses among the offenders and the measures taken to prevent the increase in mass shooting in Sweden are presented.

  9. 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

  10. Reality-based practice under pressure improves handgun shooting performance of police officers.

    NARCIS (Netherlands)

    Oudejans, R.R.D.

    2008-01-01

    The current study examined whether reality-based practice under pressure may help in preventing degradation of handgun shooting performance under pressure for police officers. Using a pre-post-test design, one group of nine police officers practised handgun shooting under pressure evoked by an

  11. Growth and morphogenesis of shoot initials of Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, in vitro

    NARCIS (Netherlands)

    Evers, P.W.

    1984-01-01

    An optimalized method of micropropagation of Douglas fir is described. Seasonal changes were found in optima for nitrate and sucrose in the medium and in the optimum for the light intensity during the culture of shoot initials. Differences in morphogenesis were obtained from shoot initials that had

  12. performance routines followed by free throw shooting accuracy in secondary basketball players

    Directory of Open Access Journals (Sweden)

    Phelps Ashley

    2015-12-01

    Full Text Available Study aim: The purpose of the current study was to determine whether existing pre-performance routines had an effect on free throw shooting accuracy in high school pupils as compared to shooting without a pre-performance routine.

  13. Experts Appear to Use Angle of Elevation Information in Basketball Shooting

    Science.gov (United States)

    de Oliveira, Rita Ferraz; Oudejans, Raoul R. D.; Beek, Peter J.

    2009-01-01

    For successful basketball shooting, players must use information about the location of the basket relative to themselves. In this study, the authors examined to what extent shooting performance depends on the absolute distance to the basket ("m") and the angle of elevation (alpha). In Experiment 1, expert players took jump shots under different…

  14. The effect of time constraints and running phases on combined event pistol shooting performance.

    Science.gov (United States)

    Dadswell, Clare; Payton, Carl; Holmes, Paul; Burden, Adrian

    2016-01-01

    The combined event is a crucial aspect of the modern pentathlon competition, but little is known about how shooting performance changes through the event. This study aimed to identify (i) how performance-related variables changed within each shooting series and (ii) how performance-related variables changed between each shooting series. Seventeen modern pentathletes completed combined event trials. An optoelectronic shooting system recorded score and pistol movement, and force platforms recorded centre of pressure movement 1 s prior to every shot. Heart rate and blood lactate values were recorded throughout the event. Whilst heart rate and blood lactate significantly increased between series (P  0.05). Thus, combined event shooting performance following each running phase appears similar to shooting performance following only 20 m of running. This finding has potential implications for the way in which modern pentathletes train for combined event shooting, and highlights the need for modern pentathletes to establish new methods with which to enhance shooting accuracy.

  15. A Hybrid Finite Element/Helmholtz-Kirchhoff-Integral Model for Shooting Range Sound Prediction

    NARCIS (Netherlands)

    Nijhof, M.J.J.; Eerden, F.J.M. van der

    2013-01-01

    National legislation enforces a limit on the Sound Levels of outdoor military shooting ranges observed in nearby residential areas. These restrictions directly influence the number of shots that may be fired at a specific shooting range, which may conflict with the required/ scheduled training

  16. When the Exception Is the Rule: School Shootings, Bare Life, and the Sovereign Self

    Science.gov (United States)

    Shapiro, Harvey

    2015-01-01

    Much discourse on school shootings tends to imply a binary separation between what is considered normal and exceptional, between an expected course of human events and sociohistorical aberrations. In this article Harvey Shapiro suggests the need for new directions in our responses: First, he shows how responses to school shootings tend to…

  17. What Can Be Done about School Shootings? A Review of the Evidence

    Science.gov (United States)

    Borum, Randy; Cornell, Dewey G.; Modzeleski, William; Jimerson, Shane R.

    2010-01-01

    School shootings have generated great public concern and fostered a widespread impression that schools are unsafe for many students; this article counters those misapprehensions by examining empirical evidence of school and community violence trends and reviewing evidence on best practices for preventing school shootings. Many of the school safety…

  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. Bud removal affects shoot, root, and callus development of hardwood Populus cuttings

    Science.gov (United States)

    A.H. Wiese; J.A. Zalesny; D.M. Donner; Ronald S., Jr. Zalesny

    2006-01-01

    The inadvertent removal and/or damage of buds during processing and planting of hardwood poplar (Populus spp.) cuttings are a concern because of their potential impact on shoot and root development during establishment. The objective of the current study was to test for differences in shoot dry mass, root dry mass, number of roots, length of the...

  20. Simulating the partitioning of biomass and nitrogen between roots and shoot in crop and grass plants

    NARCIS (Netherlands)

    Yin, X.; Schapendonk, A.H.C.M.

    2004-01-01

    Quantification of the assimilate partitioning between roots and shoot has been one of the components that need improvement in crop growth models. In this study we derived two equations for root-shoot partitioning of biomass and nitrogen (N) that hold for crops grown under steady-state conditions.

  1. Ontogeny of axillary buds and shoots in roses: Leaf initiation and pith development.

    NARCIS (Netherlands)

    Marcelis-van Acker, C.A.M.

    1994-01-01

    The ontogeny of an axillary bud (in the middle region of a shoot) from initiation up to flowering of the subsequent shoot was studied. The first secondary buds appeared in the axillary bud (primary bud) when the leaf subtending the primary bud unfolded. By that time, the primary bud contained seven

  2. Effects of visual control training on the shooting performance of elite female basketball players

    NARCIS (Netherlands)

    Oudejans, R.R.D.

    2012-01-01

    In the current study, a method was tested to train visual control in basketball shooting. Using a sender/receiver system, Plato liquid-crystal goggles were wirelessly and manually controlled by the experimenter to manipulate vision of players while they were shooting. During the training the goggles

  3. Long-term impact of shoot blight disease on red pine saplings

    Science.gov (United States)

    Linda M. Haugen; Michael E. Ostry

    2013-01-01

    Damage from Sirococcus and Diplodia shoot blights of red pine is widespread and periodically severe in the Lake States. An outbreak of shoot blight occurred in red pine sapling plantations across northern Wisconsin, northern Minnesota, and the Upper Peninsula of Michigan in 1993. We established monitoring plots in red pine sapling...

  4. Development of Sirococcus shoot blight following thinning in western hemlock regeneration.

    Science.gov (United States)

    Charles G. Shaw; Thomas H. Laurent; Spencer. Israelson

    1981-01-01

    Shoot mortality from Sirococcus strobilinus Preuss. and other causes was recorded by crown position from April 1978 through October 1979 in younggrowth western hemlock (Tsuga heterophylla (Raf.) Sarg.) crop trees released in a 1977 thinning at Thomas Bay, Alaska. All study trees contained some infected shoots, but no terminal...

  5. 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)

  6. THE PRELIMINARY STUDIES ON THE INFLUENCE OF SHOOTING RANGES ON ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Karolina Wodnik

    2017-08-01

    Full Text Available The aim of the study was to assess the impact of the shooting activity on the environment. The studies were conducted in the area of the sports shooting range. The invertebrates assemblages were identified to the family level as well as morphospecies. The second method do not require the proficiency in identification. The following indices of the biodiversity were used for the assessment of the impact of sports shooting ranges: Simpson, Shannon-Wiener, Margalef, Berger-Parker and Menhinick. A decreased biodiversity was observed at two studied sites comparing to the reference site what proves the influence of shooting activity on the biodiversity and suggest disturbance of the ecosystem integrity because of shooting activity.

  7. 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)

  8. THE EFFICIENCY OF SHOOT AND PLANTLET FORMATION OF Cephaelis ipecacuanha AFTER THREE SUBCULTURES IN VITRO

    Directory of Open Access Journals (Sweden)

    Osmar Alves Lameira

    1994-12-01

    Full Text Available Multiple adventitious shoot formed from internodal segments of Cephaelis ipecacuanha cultured 25 days on Gamborg basal medium (GAMBORG et al., 1968 supplemented with 6.66mM 6-benzylaminopurine there was a maximum of nine shoots per segment and an average of five shoots per segment formed. The presence of gibberellic acid in the subculture media promoted shoot elongation in all treatments. The shoots attained 3cm in height and rooting of 100% after 35 days of culturing upon Murashige and Skoog's basal medium (MS, added with 4.92mM indole-3-butyric acid, 0.87m gibberellic acid and 0.1% activated charcoal. Further growth was accelerated after the transfer to 1/2 MS without growth regulators. Rooted plantlets transferred to potting soil could be successfully established.

  9. 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.

  10. Language, Identity, and Exile

    Science.gov (United States)

    Erdinast-Vulcan, Daphna

    2010-01-01

    The exilic mode of being, a living on boundary-lines, produces a constant relativization of one's home, one's culture, one's language, and one's self, through the acknowledgement of otherness. It is a homesickness without nostalgia, without the desire to return to the same, to be identical to oneself. The encounter with the other which produces a…

  11. Bilingualism versus identity

    DEFF Research Database (Denmark)

    Hermann, Jesper

    1988-01-01

    During the last hundred years psychologists, philosophers and theologians have developed two different conceptions of personal identity. One of them insists that each person is a unique and transcendental being, whereas the other finds the personality deriving from interaction with other persons....... (This is the prevailing view today.) These theories are placed in relation to the difficulties an immigrant encounters....

  12. Language and Identity Explored

    Directory of Open Access Journals (Sweden)

    Thomas Rozanov

    2016-06-01

    Full Text Available The relationship between language and identity is widely discussed in applied linguistics, sociology, communications and other related scholarly fields. Furthermore, many researchers have focused on the post-Soviet region, which given its unique historical context allows for testing of this relationship. The widespread bilingualism as a result of historical russification and the linguistic transformations that occurred after the collapse of the Soviet Union make the region a ‘sociolinguistic playground’. Recent events in Ukraine have given grounds to further explore this relationship, now in attempt to link language and identity as potential forces for geopolitical change in the region. This paper presents an overview of existing research, theories, and opposing perspectives related to the relationship between language and identity, and considers complications such as historical russification, religious influence, socioeconomic factors, and education with regards to the Ukrainian and post-Soviet context.  I aim to illustrate the significance of language and its effects on socio-political change in the case of Ukraine, by presenting arguments and complications in support of the relationship between language and identity.

  13. Shifting Design Consultancy Identities

    DEFF Research Database (Denmark)

    Larsen, Henry; Huijboom, Nina; Holm Nielsen, Anne

    2014-01-01

    and identities that resonate more with freelancing and portfolio careers than with the intention of creating firms that are intended to expand. We recognized a pattern where freelancers build up their work as a portfolio by moving from one engagement to another, a process that we will call sequential freelancing...

  14. Migration, Narration, Identity

    DEFF Research Database (Denmark)

    Leese, Peter

    three consecutive summers from 2010 to 2012. The articles focus on various aspects of the migrant experience and try to answer questions about migrant identity and its representations in literature and the media. The book closes with an original play by Carlos Morton, the Chicano playwright working...

  15. The Visual Identity Project

    Science.gov (United States)

    Tennant-Gadd, Laurie; Sansone, Kristina Lamour

    2008-01-01

    Identity is the focus of the middle-school visual arts program at Cambridge Friends School (CFS) in Cambridge, Massachusetts. Sixth graders enter the middle school and design a personal logo as their first major project in the art studio. The logo becomes a way for students to introduce themselves to their teachers and to represent who they are…

  16. Work and Female Identity.

    Science.gov (United States)

    Reohr, Janet R.

    In climbing an organizational ladder dominated by males, the professional woman encounters obstacles to the more traditional feminine behaviors and mannerisms to which she may be accustomed. These obstacles may erode her sense of identity, creating difficulties both inside and outside of her work environment. Traditional distinctions between…

  17. Positioning health professional identity

    DEFF Research Database (Denmark)

    Lund, Ole; Krogh Christensen, Mette; Mørcke, Anne Mette

    2017-01-01

    Drawing on positioning theory, the purpose of this paper is to characterize the activities and positions of students and supervisors at workplaces and on-campus skills training sites across the higher health professional educations of medicine, sports science, and nursing. Furthermore, the study ...... explored the impact of work-based learning (WBL) and skills training on students’ personal professional identity development....

  18. Dissociative Identity Disorder

    Science.gov (United States)

    Schmidt, Tom

    2007-01-01

    Few psychological disorders in the Diagnostic Statistical Manual have generated as much controversy as Dissociative Identity Disorder (DID). For the past 35 years diagnoses of DID, previously referred to as Multiple Personality Disorder (MPD), have increased exponentially, causing various psychological researchers and clinicians to question the…

  19. Spatial Identity in Gagauzia

    Directory of Open Access Journals (Sweden)

    A. V. Salavatova

    2015-01-01

    Full Text Available Historically the gagauz developed a self-perception based on their difference from Moldova as well as the ‘Turkish world’. The article argues that this fact has determined their pro-Russian political orientation as the only possible way of maintaining their identity

  20. Body Integrity Identity Disorder

    NARCIS (Netherlands)

    Blom, Rianne M.; Hennekam, Raoul C.; Denys, Damiaan

    2012-01-01

    Introduction: Body Integrity Identity Disorder (BIID) is a rare, infrequently studied and highly secretive condition in which there is a mismatch between the mental body image and the physical body. Subjects suffering from BIID have an intense desire to amputate a major limb or severe the spinal