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1

Identification of genes associated with growth cessation and bud dormancy entrance using a dormancy-incapable tree mutant  

PubMed Central

Background In many tree species the perception of short days (SD) can trigger growth cessation, dormancy entrance, and the establishment of a chilling requirement for bud break. The molecular mechanisms connecting photoperiod perception, growth cessation and dormancy entrance in perennials are not clearly understood. The peach [Prunus persica (L.) Batsch] evergrowing (evg) mutant fails to cease growth and therefore cannot enter dormancy under SD. We used the evg mutant to filter gene expression associated with growth cessation after exposure to SD. Wild-type and evg plants were grown under controlled conditions of long days (16 h/8 h) followed by transfer to SD (8 h/16 h) for eight weeks. Apical tissues were sampled at zero, one, two, four, and eight weeks of SD and suppression subtractive hybridization was performed between genotypes at the same time points. Results We identified 23 up-regulated genes in the wild-type with respect to the mutant during SD exposure. We used quantitative real-time PCR to verify the expression of the differentially expressed genes in wild-type tissues following the transition to SD treatment. Three general expression patterns were evident: one group of genes decreased at the time of growth cessation (after 2 weeks in SD), another that increased immediately after the SD exposure and then remained steady, and another that increased throughout SD exposure. Conclusions The use of the dormancy-incapable mutant evg has allowed us to reduce the number of genes typically detected by differential display techniques for SD experiments. These genes are candidates for involvement in the signalling pathway leading from photoperiod perception to growth cessation and dormancy entrance and will be the target of future investigations. PMID:20144228

2010-01-01

2

Epigenetic regulation of bud dormancy events in perennial plants  

PubMed Central

Release of bud dormancy in perennial plants resembles vernalization in Arabidopsis thaliana and cereals. In both cases, a certain period of chilling is required for accomplishing the reproductive phase, and several transcription factors with the MADS-box domain perform a central regulatory role in these processes. The expression of DORMANCY-ASSOCIATED MADS-box (DAM)-related genes has been found to be up-regulated in dormant buds of numerous plant species, such as poplar, raspberry, leafy spurge, blackcurrant, Japanese apricot, and peach. Moreover, functional evidence suggests the involvement of DAM genes in the regulation of seasonal dormancy in peach. Recent findings highlight the presence of genome-wide epigenetic modifications related to dormancy events, and more specifically the epigenetic regulation of DAM-related genes in a similar way to FLOWERING LOCUS C, a key integrator of vernalization effectors on flowering initiation in Arabidopsis. We revise the most relevant molecular and genomic contributions in the field of bud dormancy, and discuss the increasing evidence for chromatin modification involvement in the epigenetic regulation of seasonal dormancy cycles in perennial plants. PMID:24917873

Rios, Gabino; Leida, Carmen; Conejero, Ana; Badenes, Maria Luisa

2014-01-01

3

Dormancy in Reproductive Vegetative Buds in Creeping Perennials  

E-print Network

. Emergence was impaired in Cirsium arvense, Equisetum arvense, Sonchus arvensis and Tussilago farfara during a period in September-October. This seasonality was, however, not preserved in C. arvense root buds after temperature. None of the 12 combinations of photoperiods and temperatures used induced dormancy in C. arvense

4

Co-ordinated gene expression during phases of dormancy release in raspberry (Rubus idaeus L.) buds.  

PubMed

Bud break in raspberry (Rubus idaeus L.) is often poor and uneven, with many of the subapical buds remaining in a dormant state. In order to determine the dormancy status of raspberry buds, an empirical measure of bud burst in a growth-permissive environment following exposure to chilling (4 degrees C cold storage) was developed. For cv. Glen Ample, percentage bud burst in intact canes and isolated nodes was recorded after 14 d. Isolated nodes (a measure of endodormancy) achieved 100% bud burst after approximately 1500 h chilling whereas buds on intact plants (combined endo- and paradormancy) required an additional 1000 h chilling. A microarray approach was used to follow changes in gene expression that occurred during dormancy transition. The probes for the microarrays were obtained from endodormant and paradormant raspberry bud cDNA libraries. The expression profiles of 5300 clones from these libraries were subjected to principal component analysis to determine the most significant expression patterns. Sequence analysis of these clones, in many cases, enabled their functional categorization and the development of hypotheses concerning the mechanisms of bud dormancy release. Thus a set of novel candidates for key dormancy-related genes from raspberry buds have been identified. Bud dormancy is fundamental to the study of plant developmental processes and, in addition, its regulation is of significant economic importance to fruit and horticultural industries. PMID:17244630

Mazzitelli, Luca; Hancock, Robert D; Haupt, Sophie; Walker, Paul G; Pont, Simon D A; McNicol, Jim; Cardle, Linda; Morris, Jenny; Viola, Roberto; Brennan, Rex; Hedley, Peter E; Taylor, Mark A

2007-01-01

5

Light and temperature sensing and signaling in induction of bud dormancy in woody plants  

Microsoft Academic Search

In woody species cycling between growth and dormancy must be precisely synchronized with the seasonal climatic variations.\\u000a Cessation of apical growth, resulting from exposure to short photoperiod (SD) and altered light quality, is gating the chain\\u000a of events resulting in bud dormancy and cold hardiness. The relative importance of these light parameters, sensed by phytochromes\\u000a and possibly a blue light

Jorunn E. Olsen

2010-01-01

6

Effects of endogenous ABA levels and temperature on cedar (Cedrus libani Loudon) bud dormancy in vitro  

Microsoft Academic Search

Axillary and apical buds of in-vitro-propagated cuttings of Cedrus libani are unable to burst at 24 °C, but this inhibition was overcome at 30 °C. Here we have used cedar microcuttings to investigate\\u000a whether the levels of endogenous hormones vary with bud dormancy and temperature. We analysed the levels of abscisic acid,\\u000a indole-3-acetic acid, zeatin, isopentenyladenine and their major metabolites

F. Piola; P. Label; P. Vergne; P. von Aderkas; R. Rohr

1998-01-01

7

Chilling-Dependent Release of Seed and Bud Dormancy in Peach Associates to Common Changes in Gene Expression  

PubMed Central

Reproductive meristems and embryos display dormancy mechanisms in specialized structures named respectively buds and seeds that arrest the growth of perennial plants until environmental conditions are optimal for survival. Dormancy shows common physiological features in buds and seeds. A genotype-specific period of chilling is usually required to release dormancy by molecular mechanisms that are still poorly understood. In order to find common transcriptional pathways associated to dormancy release, we analyzed the chilling-dependent expression in embryos of certain genes that were previously found related to dormancy in flower buds of peach. We propose the presence of short and long-term dormancy events affecting respectively the germination rate and seedling development by independent mechanisms. Short periods of chilling seem to improve germination in an abscisic acid-dependent manner, whereas the positive effect of longer cold treatments on physiological dwarfing coincides with the accumulation of phenylpropanoids in the seed. PMID:22590512

Arbona, Vicent; Gomez-Cadenas, Aurelio; Llacer, Gerardo; Badenes, Maria Luisa; Rios, Gabino

2012-01-01

8

Molecular analysis of signals controlling dormancy and growth in underground adventitious buds of leafy spurge.  

PubMed

Dormancy and subsequent regrowth of adventitious buds is a critical physiological process for many perennial plants. We have used the expression of hormone and cell cycle-responsive genes as markers to follow this process in leafy spurge (Euphorbia esula). In conjunction with earlier studies, we show that loss of mature leaves results in decreased sugar levels and increased gibberellin perception in underground adventitious buds. Gibberellin is sufficient for induction of S phase-specific but not M phase-specific gene expression. Loss of both apical and axillary buds or inhibition of polar auxin transport did not result in induction of S phase- or M phase-specific gene expression. Loss of polar auxin transport was necessary for continuation of the cell cycle and further bud development if the S phase was previously initiated. PMID:11950992

Horvath, David P; Chao, Wun S; Anderson, James V

2002-04-01

9

Candidate genes associated with bud dormancy release in blackcurrant (Ribes nigrum L.)  

PubMed Central

Background The detrimental effects of mild winter temperatures on the consistency of cropping of blackcurrant (Ribes nigrum L.) in parts of Europe have led to increasing interest in the genetic control of dormancy release in this species. This study examined patterns of gene expression in leaf buds of blackcurrant to identify key differential changes in these profiles around the time of budbreak. Results Using leaf bud tissue of blackcurrant, a cDNA library was generated as a source of blackcurrant ESTs for construction of a custom microarray, which was used to identify differential gene expression during dormancy release. Gene activity was lowest in early stages of dormancy, increasing to reach a maximum around the time of budbreak. Genes with significantly changing expression profiles were clustered and evidence is provided for the transient activity of genes previously associated with dormancy processes in other species. Expression profiling identified candidate genes which were mapped onto a blackcurrant genetic linkage map containing budbreak-related QTL. Three genes, which putatively encode calmodulin-binding protein, beta tubulin and acetyl CoA carboxylase respectively, were found to co-localise with budbreak QTL. Conclusions This study provides insight into the genetic control of dormancy transition in blackcurrant, identifying key changes in gene expression around budbreak. Genetic mapping of ESTs enabled the identification of genes which co-localise with previously-characterised blackcurrant QTL, and it is concluded that these genes have probable roles in release of dormancy and can therefore provide a basis for the development of genetic markers for future breeding deployment. PMID:20840772

2010-01-01

10

Low temperatures impact dormancy status, flowering competence, and transcript profiles in crown buds of leafy spurge.  

PubMed

Leafy spurge (Euphorbia esula) is an herbaceous perennial weed that produces vegetatively from an abundance of underground adventitious buds. In this study, we report the effects of different environmental conditions on vegetative production and flowering competence, and determine molecular mechanisms associated with dormancy transitions under controlled conditions. Reduction in temperature (27-10 degrees C) and photoperiod (16-8 h) over a 3-month period induced a para- to endo-dormant transition in crown buds. An additional 11 weeks of cold (5-7 degrees C) and short-photoperiod resulted in accelerated shoot growth from crown buds, and 99% floral competence when plants were returned to growth-promoting conditions. Exposure of paradormant plants to short-photoperiod and prolonged cold treatment alone had minimal affect on growth potential and resulted in ~1% flowering. Likewise, endodormant crown buds without prolonged cold treatment displayed delayed shoot growth and ~2% flowering when returned to growth-promoting conditions. Transcriptome analysis revealed that 373 and 260 genes were differentially expressed (P < 0.005) during para- to endo-dormant and endo- to eco-dormant transitions, respectively. Transcripts from flower competent vs. non-flower competent crown buds identified 607 differentially expressed genes. Further, sub-network analysis identified expression targets and binding partners associated with circadian clock, dehydration/cold signaling, phosphorylation cascades, and response to abscisic acid, ethylene, gibberellic acid, and jasmonic acid, suggesting these central regulators affect well-defined phases of dormancy and flowering. Potential genetic pathways associated with these dormancy transitions and flowering were used to develop a proposed conceptual model. PMID:20340040

Do?ramaci, Münevver; Horvath, David P; Chao, Wun S; Foley, Michael E; Christoffers, Michael J; Anderson, James V

2010-05-01

11

Bud dormancy release in elm (Ulmus spp.) clones--a case study of photoperiod and temperature responses.  

PubMed

Dormancy release as influenced by duration of outdoor winter chilling in Florence (Italy) was studied under different photoperiodic and temperature treatments in collected twigs of two European (Ulmus glabra Huds. and Ulmus minor Mill.) and four Asian (Ulmus pumila L., Ulmus parvifolia Jacq., Ulmus macrocarpa Hance and Ulmus villosa Brandis) elm clones. Photoperiod had no effect on dormancy release, and there was no evidence that photoperiod affected bud burst during quiescence in the studied elm clones. Thermal time (day degrees >0 degrees C) to bud burst decreased in all the clones with increasing outdoor chilling. Although all the clones exhibited a rather weak dormancy, they significantly differed from each other. Dormancy was released earlier in the Asian than in the European clones, and the clones could be ranked from the U. pumila clone (very weak and short dormancy) to the U. minor clone (relatively stronger and longer dormancy), the other clones being intermediate. In all the clones except U. minor, the observed decrement in thermal time to bud burst was efficiently explained as an inverse exponential function of the number of chill days < or =5 degrees C received outdoor in autumn and winter. Endodormancy, as measured by the single-node cuttings test, was weak and short in all the clones. The latter result suggests that correlative inhibitions were largely responsible for preventing bud burst during winter in these elm clones. PMID:20022864

Ghelardini, Luisa; Santini, Alberto; Black-Samuelsson, Sanna; Myking, Tor; Falusi, Mauro

2010-02-01

12

The Cold Awakening of Doritaenopsis ‘Tinny Tender’ Orchid Flowers: The Role of Leaves in Cold-induced Bud Dormancy Release  

Microsoft Academic Search

Massive flowering of tropical Phalaenopsis orchids is coordinated by the cold-induced release of reproductive bud dormancy. Light and temperature are the two key factors\\u000a integrated by the dormancy mechanism to both stop and reactivate the meristem development of many other angiosperm species,\\u000a including fruit trees and ornamental plants. It is well established that leaves and roots play a major role

Qiaoping Qin; Quentin Kaas; Chi Zhang; Luping Zhou; Xiaoyan Luo; Mingbing Zhou; Xiaoming Sun; Lanlan Zhang; Kee-Yoeup Paek; Yongyi Cui

13

Transcriptional profiling of bud dormancy induction and release in oak by next-generation sequencing  

PubMed Central

Background In temperate regions, the time lag between vegetative bud burst and bud set determines the duration of the growing season of trees (i.e. the duration of wood biomass production). Dormancy, the period during which the plant is not growing, allows trees to avoid cold injury resulting from exposure to low temperatures. An understanding of the molecular machinery controlling the shift between these two phenological states is of key importance in the context of climatic change. The objective of this study was to identify genes upregulated during endo- and ecodormancy, the two main stages of bud dormancy. Sessile oak is a widely distributed European white oak species. A forcing test on young trees was first carried out to identify the period most likely to correspond to these two stages. Total RNA was then extracted from apical buds displaying endo- and ecodormancy. This RNA was used for the generation of cDNA libraries, and in-depth transcriptome characterization was performed with 454 FLX pyrosequencing technology. Results Pyrosequencing produced a total of 495,915 reads. The data were cleaned, duplicated reads removed, and sequences were mapped onto the oak UniGene data. Digital gene expression analysis was performed, with both R statistics and the R-Bioconductor packages (edgeR and DESeq), on 6,471 contigs with read numbers ? 5 within any contigs. The number of sequences displaying significant differences in expression level (read abundance) between endo- and ecodormancy conditions ranged from 75 to 161, depending on the algorithm used. 13 genes displaying significant differences between conditions were selected for further analysis, and 11 of these genes, including those for glutathione-S-transferase (GST) and dehydrin xero2 (XERO2) were validated by quantitative PCR. Conclusions The identification and functional annotation of differentially expressed genes involved in the “response to abscisic acid”, “response to cold stress” and “response to oxidative stress” categories constitutes a major step towards characterization of the molecular network underlying vegetative bud dormancy, an important life history trait of long-lived organisms. PMID:23575249

2013-01-01

14

Comparative proteomic and transcriptomic approaches to address the active role of GA4 in Japanese apricot flower bud dormancy release  

PubMed Central

Hormones are closely associated with dormancy in deciduous fruit trees, and gibberellins (GAs) are known to be particularly important. In this study, we observed that GA4 treatment led to earlier bud break in Japanese apricot. To understand better the promoting effect of GA4 on the dormancy release of Japanese apricot flower buds, proteomic and transcriptomic approaches were used to analyse the mechanisms of dormancy release following GA4 treatment, based on two-dimensional gel electrophoresis (2-DE) and digital gene expression (DGE) profiling, respectively. More than 600 highly reproducible protein spots (P<0.05) were detected and, following GA4 treatment, 38 protein spots showed more than a 2-fold difference in expression, and 32 protein spots were confidently identified according to the databases. Compared with water treatment, many proteins that were associated with energy metabolism and oxidation–reduction showed significant changes after GA4 treatment, which might promote dormancy release. We observed that genes at the mRNA level associated with energy metabolism and oxidation–reduction also played an important role in this process. Analysis of the functions of the identified proteins and genes and the related metabolic pathways would provide a comprehensive proteomic and transcriptomic view of the coordination of dormancy release after GA4 treatment in Japanese apricot flower buds. PMID:24014872

Zhuang, Weibing; Gao, Zhihong; Zhang, Zhen

2013-01-01

15

Changes in the expression of carbohydrate metabolism genes during three phases of bud dormancy in leafy spurge.  

PubMed

Underground adventitious buds of leafy spurge (Euphorbia esula) undergo three well-defined phases of dormancy, para-, endo-, and ecodormancy. In this study, relationships among genes involved in carbohydrate metabolism and bud dormancy were examined after paradormancy release (growth induction) by decapitation and in response to seasonal signals. Real-time PCR was used to determine the expression levels of carbohydrate metabolism genes at different phases of bud dormancy. Among differentially-regulated genes, expression of a specific Euphorbia esula beta-amylase gene (Ee-BAM1) increased 100-fold after growth induction and 16,000-fold from July (paradormancy) to December (ecodormancy). Sequence data analysis indicated that two genes, Ee-BAM1 and Ee-BAM2, could encode this beta-amylase. However, real-time PCR using gene-specific primer pairs only amplified Ee-BAM1, indicating that Ee-BAM2 is either specific to other organs or not abundant. The deduced amino acid sequences of these two genes are very similar at the N-terminal but differ at the C-terminal. Both contain a nearly identical, predicted 48-amino acid plastid transit peptide. Immunoblot analyses identified a 29 kD (mature Ee-BAM1 after cleavage of the transit peptide) and a 35 kD (unprocessed EeBAM1) protein. Both 35 and 29 kD proteins were constitutively expressed in growth-induced and seasonal samples. Immunolocalization indicated that Ee-BAM1 is in the cytosol of cells at the shoot tip of the bud. Ee-BAM1 also surrounds the amyloplasts in mature cells toward the base of the bud. These observations suggests that Ee-BAM1 may have dual functions; serving as reserve protein in the cytosol and as a degrading enzyme at the surface of amyloplasts. PMID:19924545

Chao, Wun S; Serpe, Marcelo D

2010-05-01

16

Conservation and divergence of four kiwifruit SVP-like MADS-box genes suggest distinct roles in kiwifruit bud dormancy and flowering  

PubMed Central

MADS-box genes similar to Arabidopsis SHORT VEGETATIVE PHASE (SVP) have been implicated in the regulation of flowering in annual species and bud dormancy in perennial species. Kiwifruit (Actinidia spp.) are woody perennial vines where bud dormancy and out-growth affect flower development. To determine the role of SVP-like genes in dormancy and flowering of kiwifruit, four MADS-box genes with homology to Arabidopsis SVP, designated SVP1, SVP2, SVP3, and SVP4, have been identified and analysed in kiwifruit and functionally characterized in Arabidopsis. Phylogenetic analysis indicate that these genes fall into different sub-clades within the SVP-like gene group, suggesting distinct functions. Expression was generally confined to vegetative tissues, and increased transcript accumulation in shoot buds over the winter period suggests a role for these genes in bud dormancy. Down-regulation before flower differentiation indicate possible roles as floral repressors. Over-expression and complementation studies in Arabidopsis resulted in a range of floral reversion phenotypes arising from interactions with Arabidopsis MADS-box proteins, but only SVP1 and SVP3 were able to complement the svp mutant. These results suggest that the kiwifruit SVP-like genes may have distinct roles during bud dormancy and flowering. PMID:22071267

Wu, Rong-Mei; Walton, Eric F.; Richardson, Annette C.; Wood, Marion; Hellens, Roger P.; Varkonyi-Gasic, Erika

2012-01-01

17

Effect of Photoperiod on Key Enzyme Activities of Respiration in Nectarine Buds During Dormancy Induction  

Microsoft Academic Search

Shuguang (Prunus persica var. nectariana cv. Shuguang) nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sprouting ability. Spectrophotometry was used to investigate activities of phosphohexose isomerase (PGI), malic dehydrogenase (MDH), and glucose-6-phosphate dehydrogenase (G6PDH). The results revealed that short day (SD) treatment promoted dormancy induction while

Dong-mei LI; Ling LI; Yue TAN; Xiu-de CHEN; Hai-sen ZHANG; Dong-sheng GAO; Jin LI

2011-01-01

18

Gene-expression profiling of grape bud response to two alternative dormancy-release stimuli expose possible links between impaired mitochondrial activity, hypoxia, ethylene-ABA interplay and cell enlargement  

Microsoft Academic Search

A grape-bud-oriented genomic platform was produced for a large-scale comparative analysis of bud responses to two stimuli\\u000a of grape-bud dormancy release, hydrogen cyanamide (HC) and heat shock (HS). The results suggested considerable similarity\\u000a in bud response to the stimuli, both in the repertoire of responding genes and in the temporary nature of the transcriptome\\u000a reprogramming. Nevertheless, the bud response to

Ron Ophir; Xuequn Pang; Tamar Halaly; Jaganatha Venkateswari; Shimon Lavee; David Galbraith; Etti

2009-01-01

19

ptr-MIR169 is a posttranscriptional repressor of PtrHAP2 during vegetative bud dormancy period of aspen (Populus tremuloides) trees  

SciTech Connect

Highlights: ? We show a novel microRNA-mediated mechanism for control of bud dormancy in trees. ? ptr-MIR169a and PtrHAP2–5 gene showed inverse expression during dormancy period. ? The PtrHAP2–5 decline in abundance correlated with high ptr-MIR169a levels. ? PtrHAP2–5 cleavage occurred at the miR169 site during PtrHAP2–5 transcript decline. ? Our results show that miR169 attenuates PtrHAP2–5 transcript during dormancy. -- Abstract: Dormancy is a mechanism evolved in woody perennial plants to survive the winter freezing and dehydration stress via temporary suspension of growth. We have identified two aspen microRNAs (ptr-MIR169a and ptr-MIR169h) which were highly and specifically expressed in dormant floral and vegetative buds. ptr-MIR169a and its target gene PtrHAP2–5 showed inverse expression patterns during the dormancy period. ptr-MIR169a transcript steadily increased through the first half of the dormancy period and gradually declined with the approach of active growing season. PtrHAP2–5 abundance was higher in the beginning of the dormancy period but rapidly declined thereafter. The decline of PtrHAP2–5 correlated with the high levels of ptr-MIR169a accumulation, suggesting miR169-mediated attenuation of the target PtrHAP2–5 transcript. We experimentally verified the cleavage of PtrHAP2–5 at the predicted miR169a site at the time when PtrHAP2–5 transcript decline was observed. HAP2 is a subunit of a nuclear transcription factor Y (NF-Y) complex consisting of two other units, HAP3 and HAP5. Using digital expression profiling we show that poplar HAP2 and HAP5 are preferentially detected in dormant tissues. Our study shows that microRNAs play a significant and as of yet unknown and unstudied role in regulating the timing of bud dormancy in trees.

Potkar, Rewati; Recla, Jill [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)] [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Busov, Victor, E-mail: vbusov@mtu.edu [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)] [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)

2013-02-15

20

BRANCHED1 Promotes Axillary Bud Dormancy in Response to Shade in Arabidopsis[C][W  

PubMed Central

Plants interpret a decrease in the red to far-red light ratio (R:FR) as a sign of impending shading by neighboring vegetation. This triggers a set of developmental responses known as shade avoidance syndrome. One of these responses is reduced branching through suppression of axillary bud outgrowth. The Arabidopsis thaliana gene BRANCHED1 (BRC1), expressed in axillary buds, is required for branch suppression in response to shade. Unlike wild-type plants, brc1 mutants develop several branches after a shade treatment. BRC1 transcription is positively regulated 4 h after exposure to low R:FR. Consistently, BRC1 is negatively regulated by phytochrome B. Transcriptional profiling of wild-type and brc1 buds of plants treated with simulated shade has revealed groups of genes whose mRNA levels are dependent on BRC1, among them a set of upregulated abscisic acid response genes and two networks of cell cycle– and ribosome-related downregulated genes. The downregulated genes have promoters enriched in TEOSINTE BRANCHED1, CYCLOIDEA, and PCF (TCP) binding sites, suggesting that they could be transcriptionally regulated by TCP factors. Some of these genes respond to BRC1 in seedlings and buds, supporting their close relationship with BRC1 activity. This response may allow the rapid adaptation of plants to fluctuations in the ratio of R:FR light. PMID:23524661

Gonzalez-Grandio, Eduardo; Poza-Carrion, Cesar; Sorzano, Carlos Oscar S.; Cubas, Pilar

2013-01-01

21

Chilling of dormant buds hyperinduces FLOWERING LOCUS T and recruits GA-inducible 1,3-beta-glucanases to reopen signal conduits and release dormancy in Populus.  

PubMed

In trees, production of intercellular signals and accessibility of signal conduits jointly govern dormancy cycling at the shoot apex. We identified 10 putative cell wall 1,3-?-glucanase genes (glucan hydrolase family 17 [GH17]) in Populus that could turn over 1,3-?-glucan (callose) at pores and plasmodesmata (PD) and investigated their regulation in relation to FT and CENL1 expression. The 10 genes encode orthologs of Arabidopsis thaliana BG_ppap, a PD-associated glycosylphosphatidylinositol (GPI) lipid-anchored protein, the Arabidopsis PD callose binding protein PDCB, and a birch (Betula pendula) putative lipid body (LB) protein. We found that these genes were differentially regulated by photoperiod, by chilling (5°C), and by feeding of gibberellins GA(3) and GA(4). GA(3) feeding upregulated all LB-associated GH17s, whereas GA(4) upregulated most GH17s with a GPI anchor and/or callose binding motif, but only GA(4) induced true bud burst. Chilling upregulated a number of GA biosynthesis and signaling genes as well as FT, but not CENL1, while the reverse was true for both GA(3) and GA(4). Collectively, the results suggest a model for dormancy release in which chilling induces FT and both GPI lipid-anchored and GA(3)-inducible GH17s to reopen signaling conduits in the embryonic shoot. When temperatures rise, the reopened conduits enable movement of FT and CENL1 to their targets, where they drive bud burst, shoot elongation, and morphogenesis. PMID:21282527

Rinne, Päivi L H; Welling, Annikki; Vahala, Jorma; Ripel, Linda; Ruonala, Raili; Kangasjärvi, Jaakko; van der Schoot, Christiaan

2011-01-01

22

A rapid transcriptional activation is induced by the dormancy-breaking chemical hydrogen cyanamide in kiwifruit (Actinidia deliciosa) buds  

Microsoft Academic Search

Budbreak in kiwifruit (Actinidia deliciosa) can be poor in locations that have warm winters with insufficient winter chilling. Kiwifruit vines are often treated with the dormancy-breaking chemical hydrogen cyanamide (HC) to increase and synchronize budbreak. This treatment also offers a tool to understand the processes involved in budbreak. A genomics approach is presented here to increase our understanding of budbreak

Eric F. Walton; Rong-Mei Wu; Annette C. Richardson; Marcus Davy; Roger P. Hellens; Kate Thodey; Bart J. Janssen; Andrew P. Gleave; Georgina M. Rae; Marion Wood; Robert J. Schaffer

2009-01-01

23

A rapid transcriptional activation is induced by the dormancy-breaking chemical hydrogen cyanamide in kiwifruit (Actinidia deliciosa) buds  

PubMed Central

Budbreak in kiwifruit (Actinidia deliciosa) can be poor in locations that have warm winters with insufficient winter chilling. Kiwifruit vines are often treated with the dormancy-breaking chemical hydrogen cyanamide (HC) to increase and synchronize budbreak. This treatment also offers a tool to understand the processes involved in budbreak. A genomics approach is presented here to increase our understanding of budbreak in kiwifruit. Most genes identified following HC application appear to be associated with responses to stress, but a number of genes appear to be associated with the reactivation of growth. Three patterns of gene expression were identified: Profile 1, an HC-induced transient activation; Profile 2, an HC-induced transient activation followed by a growth-related activation; and Profile 3, HC- and growth-repressed. One group of genes that was rapidly up-regulated in response to HC was the glutathione S-transferase (GST) class of genes, which have been associated with stress and signalling. Previous budbreak studies, in three other species, also report up-regulated GST expression. Phylogenetic analysis of these GSTs showed that they clustered into two sub-clades, suggesting a strong correlation between their expression and budbreak across species. PMID:19651683

Walton, Eric F.; Wu, Rong-Mei; Richardson, Annette C.; Davy, Marcus; Hellens, Roger P.; Thodey, Kate; Janssen, Bart J.; Gleave, Andrew P.; Rae, Georgina M.; Wood, Marion; Schaffer, Robert J.

2009-01-01

24

Transcriptome analysis identifies novel responses and potential regulatory genes involved in seasonal dormancy transitions of leafy spurge (Euphorbia esula L.)  

Microsoft Academic Search

BACKGROUND: Dormancy of buds is a critical developmental process that allows perennial plants to survive extreme seasonal variations in climate. Dormancy transitions in underground crown buds of the model herbaceous perennial weed leafy spurge were investigated using a 23 K element cDNA microarray. These data represent the first large-scale transcriptome analysis of dormancy in underground buds of an herbaceous perennial

David P Horvath; Wun S Chao; Jeffrey C Suttle; Jyothi Thimmapuram; James V Anderson

2008-01-01

25

Stamen development and winter dormancy in apricot (Prunus armeniaca)  

PubMed Central

Background and Aims In temperate woody perennials, flower bud development is halted during the winter, when the buds enter dormancy. This dormant period is a prerequisite for adequate flowering, is genetically regulated, and plays a clear role in possibly adapting species and cultivars to climatic areas. However, information on the biological events underpinning dormancy is lacking. Stamen development, with clear differentiated stages, appears as a good framework to put dormancy in a developmental context. Here, stamen developmental changes are characterized in apricot (Prunus armeniaca) and are related to dormancy. Methods Stamen development was characterized cytochemically from the end of August to March, over 4 years. Developmental changes were related to dormancy, using the existing empirical information on chilling requirements. Key Results Stamen development continued during the autumn, and the flower buds entered dormancy with a fully developed sporogenous tissue. Although no anatomical changes were observed during dormancy, breaking of dormancy occurred following a clear sequence of events. Starch accumulated in particular places, pre-empting further development in those areas. Vascular bundles developed and pollen mother cells underwent meiosis followed by microspore development. Conclusions Dormancy appears to mark a boundary between the development of the sporogenous tissue and the occurrence of meiosis for further microspore development. Breaking of dormancy occurs following a clear sequence of events, providing a developmental context in which to study winter dormancy and to evaluate differences in chilling requirements among genotypes. PMID:21474504

Julian, C.; Rodrigo, J.; Herrero, M.

2011-01-01

26

Acetylated H4 histone and genomic DNA methylation patterns during bud set and bud burst in Castanea sativa.  

PubMed

The relationships between genomic DNA cytosine methylation, histone H4 acetylation and bud dormancy in Castanea sativa are described. Acetylated H4 histone and genomic DNA methylation patterns showed opposite abundance patterns during bud set and bud burst. Increased and decreased methylation levels in the apical buds coincided with bud set and bud burst, respectively. Intermediate axillary buds were characterized by constant levels of DNA methylation during burst of apical buds and reduced fluctuation in DNA methylation throughout the year, which coincided with the absence of macro-morphological changes. Furthermore, acetylated histone H4 (AcH4) levels from apical buds were higher during bud burst than during bud set, as was demonstrated by immunodetection. Results were validated with three additional C. sativa provenances. Thus, global DNA methylation and AcH4 levels showed opposite patterns and coincided with changes in bud dormancy in C. sativa. PMID:19376609

Santamaría, Ma Estrella; Hasbún, Rodrigo; Valera, Ma José; Meijón, Mónica; Valledor, Luis; Rodríguez, Jose L; Toorop, Peter E; Cañal, Ma Jesús; Rodríguez, Roberto

2009-09-01

27

Changes in the activities of catalase, peroxidase, and polyphenol oxidase in apple buds during bud break induced by thidiazuron  

Microsoft Academic Search

The breaking of dormancy in apple buds (Malus domestica Borkh cv. York Imperial) by thidiazuron (N-phenyl-N?-1,2,3,-thidiazol-5-ylurea) was investigated in relation to catalase, peroxidase, and polyphenol oxidase activities and their\\u000a isoenzyme patterns. The activity and number of isoenzymic components of catalase increased progressively during bud break,\\u000a then decreased after buds started to grow. Peroxidase activity was highest during dormancy and declined

Shiow Y. Wang; Hong J. Jiao; Miklos Faust

1991-01-01

28

Transcriptome variation along bud development in grapevine (Vitis vinifera L.)  

PubMed Central

Background Vegetative buds provide plants in temperate environments the possibility for growth and reproduction when environmental conditions are favorable. In grapevine, crucial developmental events take place within buds during two growing seasons in consecutive years. The first season, the shoot apical meristem within the bud differentiates all the basic elements of the shoot including flowering transition in lateral primordia and development of inflorescence primordia. These events practically end with bud dormancy. The second season, buds resume shoot growth associated to flower formation and development. Gene expression has been previously monitored at specific stages of bud development but has never been followed along the two growing seasons. Results Gene expression changes were analyzed along the bud annual cycle at eight different time points. Principal Components Analysis (PCA) revealed that the main factors explaining the global gene expression differences were the processes of bud dormancy and active growth as well as stress responses. Accordingly, non dormant buds showed an enrichment in functional categories typical of actively proliferating and growing cells together with the over abundance of transcripts belonging to stress response pathways. Differential expression analyses performed between consecutive time points indicated that major transcriptional changes were associated to para/endodormancy, endo/ecodormancy and ecodormancy/bud break transitions. Transcripts encoding key regulators of reproductive development were grouped in three major expression clusters corresponding to: (i) transcripts associated to flowering induction, (ii) transcripts associated to flower meristem specification and initiation and (iii) transcripts putatively involved in dormancy. Within this cluster, a MADS-box gene (VvFLC2) and other transcripts with similar expression patterns could participate in dormancy regulation. Conclusions This work provides a global view of major transcriptional changes taking place along bud development in grapevine, highlighting those molecular and biological functions involved in the main events of bud development. As reported in other woody species, the results suggest that genes regulating flowering could also be involved in dormancy regulatory pathways in grapevine. PMID:23035802

2012-01-01

29

Transcriptome analysis identifies novel responses and potential regulatory genes involved in seasonal dormancy transitions of leafy spurge (Euphorbia esula L.)  

PubMed Central

Background Dormancy of buds is a critical developmental process that allows perennial plants to survive extreme seasonal variations in climate. Dormancy transitions in underground crown buds of the model herbaceous perennial weed leafy spurge were investigated using a 23 K element cDNA microarray. These data represent the first large-scale transcriptome analysis of dormancy in underground buds of an herbaceous perennial species. Crown buds collected monthly from August through December, over a five year period, were used to monitor the changes in the transcriptome during dormancy transitions. Results Nearly 1,000 genes were differentially-expressed through seasonal dormancy transitions. Expected patterns of gene expression were observed for previously characterized genes and physiological processes indicated that resolution in our analysis was sufficient for identifying shifts in global gene expression. Conclusion Gene ontology of differentially-expressed genes suggests dormancy transitions require specific alterations in transport functions (including induction of a series of mitochondrial substrate carriers, and sugar transporters), ethylene, jasmonic acid, auxin, gibberellic acid, and abscisic acid responses, and responses to stress (primarily oxidative and cold/drought). Comparison to other dormancy microarray studies indicated that nearly half of the genes identified in our study were also differentially expressed in at least two other plant species during dormancy transitions. This comparison allowed us to identify a particular MADS-box transcription factor related to the DORMANCY ASSOCIATED MADS-BOX genes from peach and hypothesize that it may play a direct role in dormancy induction and maintenance through regulation of FLOWERING LOCUS T. PMID:19014493

Horvath, David P; Chao, Wun S; Suttle, Jeffrey C; Thimmapuram, Jyothi; Anderson, James V

2008-01-01

30

Seed coat structure and dormancy  

Microsoft Academic Search

An understanding of dormancy mechanisms is of ecological and economic importance. Identification of the level at which dormancy is imposed appears to be species specific. The variation brought about by this therefore requires that developmental studies be included in seed coat dormancy experiments. In most cases, a site of permeability can be identified during the developmental process, and this information

K. M. Kelly; J. Staden; W. E. Bell

1992-01-01

31

Seed dormancy in alpine species  

PubMed Central

In alpine species the classification of the various mechanisms underlying seed dormancy has been rather questionable and controversial. Thus, we investigated 28 alpine species to evaluate the prevailing types of dormancy. Embryo type and water impermeability of seed coats gave an indication of the potential seed dormancy class. To ascertain the actual dormancy class and level, we performed germination experiments comparing the behavior of seeds without storage, after cold-dry storage, after cold-wet storage, and scarification. We also tested the light requirement for germination in some species. Germination behavior was characterized using the final germination percentage and the mean germination time. Considering the effects of the pretreatments, a refined classification of the prevailing dormancy types was constructed based on the results of our pretreatments. Only two out of the 28 species that we evaluated had predominantly non-dormant seeds. Physiological dormancy was prevalent in 20 species, with deep physiological dormancy being the most abundant, followed by non-deep and intermediate physiological dormancy. Seeds of four species with underdeveloped embryos were assigned to the morphophysiologial dormancy class. An impermeable seed coat was identified in two species, with no additional physiological germination block. We defined these species as having physical dormancy. Light promoted the germination of seeds without storage in all but one species with physiological dormancy. In species with physical dormancy, light responses were of minor importance. We discuss our new classification in the context of former germination studies and draw implications for the timing of germination in the field. PMID:24415831

Schwienbacher, Erich; Navarro-Cano, Jose Antonio; Neuner, Gilbert; Erschbamer, Brigitta

2011-01-01

32

Quantitative trait loci and candidate gene mapping of bud set and bud flush in populus.  

PubMed Central

The genetic control of bud phenology in hybrid poplar was studied by mapping quantitative trait loci (QTL) affecting the timing of autumn bud set and spring bud flush. The founders of the mapping pedigree were collected from widely separated latitudes to maximize segregating variation for dormancy-related traits in the F(2) generation-the female Populus trichocarpa parent is from Washington State (48 degrees N) and the male P. deltoides parent is from Texas (31 degrees N). Bud set and bud flush timing were measured on the F(2) generation in a replicated clonal field trial. Using a linkage map constructed of AFLP and microsatellite markers, three QTL controlling bud set and six QTL controlling bud flush were detected. Additionally, five candidate genes believed to be involved in perception of photoperiod (PHYB1, PHYB2) or transduction of abscisic acid response signals (ABI1B, ABI1D, and ABI3) were placed on the QTL map. PHYB2 and ABI1B were found to be coincident with QTL affecting bud set and bud flush. PMID:10655234

Frewen, B E; Chen, T H; Howe, G T; Davis, J; Rohde, A; Boerjan, W; Bradshaw, H D

2000-01-01

33

Yield stability of peach germplasm differing in dormancy and blooming season in the Mexican subtropics  

Microsoft Academic Search

Peach cultivation in Mexico has recently extended to subtropical climates to reduce drought, but in many areas winter frosts are a strong limiting factor. Information about the behavior of a wide range of peach accessions during dormancy and bud-break was collected over a 4-year period in the most important peach growing region in the subtropical highlands of central Mexico where

S Pérez

2004-01-01

34

Water impermeable seed dormancy  

Microsoft Academic Search

Viable seeds that do not imbibe water and thus fail to germinate in an apparently favorable environment are commonly termed\\u000a impermeable or hard seed. This physical, exogenous dormancy is especially common in species of the Fabaceae. The ecological\\u000a significance of hard seed includes the ability to rapidly recolonize burnt areas after fire and to withstand ingestion by\\u000a animals and birds.

M. Philip Rolston

1978-01-01

35

Early wound reactions of Japanese maple during winter dormancy: the effect of two contrasting temperature regimes  

PubMed Central

During winter dormancy, temperate trees are capable of only a restricted response to wounding. Depending on the ambient temperature during winter dormancy, wounded trees may start compartmentalization, e.g. by producing inhibitory compounds, but it is thought that processes involving cell proliferation, such as the formation of callus and wound xylem, are delayed until the next growing season. We investigated the effect of two contrasting temperature regimes on early reactions of Acer palmatum trees to wounding during winter bud dormancy. Stems of A. palmatum trees were wounded and stored under an ambient temperature of 4 or 15 °C for 3 weeks during winter bud dormancy. We then studied wound reactions in the living bark, cambial region and xylem. In the 4 °C treatment, wound reactions were virtually absent. In the 15 °C treatment, however, trees reacted to wounding by dieback of the cortex and phloem and by the formation of ligno-suberized layers. In the cambial zone, cambial dieback occurred and callus tissue and wound xylem were formed locally, close to the wound margins. In the xylem, compartmentalization took place by deposition of inhibitory compounds in fibre cells and vessel elements. We conclude that temperature is an important factor in wound reactions during winter dormancy, and may even induce proliferation of callus and wound xylem within a 3-week period. It therefore seems likely that trees that have been wounded during dormancy in areas with mild or warm winters might cope better with wounding, as unlike trees in cold environments, they may compartmentalize wounds even during winter dormancy. PMID:25275087

Copini, Paul; den Ouden, Jan; Decuyper, Mathieu; Mohren, Godefridus M. J.; Loomans, Antoon J. M.; Sass-Klaassen, Ute

2014-01-01

36

Entrance Examinations as Gatekeepers  

ERIC Educational Resources Information Center

Research on teacher education entrance examinations has become a significant branch of educational research in Finland. Class teacher selections are of great importance to get those applicants into training who are the most suitable for the teaching profession. This article investigates how successful entrance examinations are, as well as the…

Valli, Raine; Johnson, Peter

2007-01-01

37

Release of apical dominance in potato tuber is accompanied by programmed cell death in the apical bud meristem.  

PubMed

Potato (Solanum tuberosum) tuber, a swollen underground stem, is used as a model system for the study of dormancy release and sprouting. Natural dormancy release, at room temperature, is initiated by tuber apical bud meristem (TAB-meristem) sprouting characterized by apical dominance (AD). Dormancy is shortened by treatments such as bromoethane (BE), which mimics the phenotype of dormancy release in cold storage by inducing early sprouting of several buds simultaneously. We studied the mechanisms governing TAB-meristem dominance release. TAB-meristem decapitation resulted in the development of increasing numbers of axillary buds with time in storage, suggesting the need for autonomous dormancy release of each bud prior to control by the apical bud. Hallmarks of programmed cell death (PCD) were identified in the TAB-meristems during normal growth, and these were more extensive when AD was lost following either extended cold storage or BE treatment. Hallmarks included DNA fragmentation, induced gene expression of vacuolar processing enzyme1 (VPE1), and elevated VPE activity. VPE1 protein was semipurified from BE-treated apical buds, and its endogenous activity was fully inhibited by a cysteinyl aspartate-specific protease-1-specific inhibitor N-Acetyl-Tyr-Val-Ala-Asp-CHO (Ac-YVAD-CHO). Transmission electron microscopy further revealed PCD-related structural alterations in the TAB-meristem of BE-treated tubers: a knob-like body in the vacuole, development of cytoplasmic vesicles, and budding-like nuclear segmentations. Treatment of tubers with BE and then VPE inhibitor induced faster growth and recovered AD in detached and nondetached apical buds, respectively. We hypothesize that PCD occurrence is associated with the weakening of tuber AD, allowing early sprouting of mature lateral buds. PMID:22362870

Teper-Bamnolker, Paula; Buskila, Yossi; Lopesco, Yael; Ben-Dor, Shifra; Saad, Inbal; Holdengreber, Vered; Belausov, Eduard; Zemach, Hanita; Ori, Naomi; Lers, Amnon; Eshel, Dani

2012-04-01

38

Physiological processes during winter dormancy and their ecological significance  

SciTech Connect

Lengthy and severe winters require that trees in the forests of boreal and mountain zones undergo winter dormancy. Physiologically, a high resistance to subfreezing temperatures and concomitant dehydration are necessary. To accomplish this dormancy, both physiological and structural changes are needed at the cellular level that require induction by endogenous and photoperiodic control early in autumn. Endogenous rhythmicity promotes cold hardening in early autumn and the persistence of hardiness throughout the winter. Numerous physiological functions are maintained at a reduced level, or become completely inhibited during true winter dormancy. Winter hardiness also includes the capability to minimize water loss effectively when water uptake is severely impeded or impossible. Anatomical features such as tracheids act to minimize xylem embolism during frequent freeze-thaw cycles, and {open_quotes}crown{close_quotes} tissues enable buds to stay in a dehydrated and, thus, more resistant state during winter. Both these structural features are adaptations that contribute to the dominance of conifers in cold climates. Interestingly, deciduous tree species rather than evergreen conifers dominate in the most severe winter climates, although it is not clear whether limitations during winter, during the summer growth period, or during both are most limiting to conifer tree ecology. Additional work that evaluates the importance of winter and summer growth restriction, and their interaction, is needed before a comprehensive understanding of conifer tree ecophysiology will be possible.

Havranek, W.M.; Tranquillini, W.

1995-07-01

39

Catalase inhibition accelerates dormancy release and sprouting in potato (Solanum tuberosum L.) tubers  

Microsoft Academic Search

The involvement of hydrogen peroxide (H2O2) metabolism in dormancy release and sprouting of potato (Solanum tuberosum L.) tubers has been investigated using three complementary approaches. In the fi rst approach, the evolution of the sprouting kinetics, H2O2 content and antioxidant enzyme activities were examined during tuber storage. The most important changes occurred at the « bud\\/sprout » level. In particular,

Mohammed Bajji; Frédéric Gastiny

2007-01-01

40

Expressional regulation of PpDAM5 and PpDAM6, peach (Prunus persica) dormancy-associated MADS-box genes, by low temperature and dormancy-breaking reagent treatment  

PubMed Central

The present study investigated the expressional regulation of PpDAM5 and PpDAM6, two of the six peach (Prunus persica) dormancy-associated MADS-box genes, in relation to lateral bud endodormancy. PpDAM5 and PpDAM6 were originally identified as homologues of Arabidopsis SHORT VEGETATIVE PHASE/AGAMOUS-LIKE 24 identified in the EVERGROWING locus of peach. Furthermore, PpDAM5 and PpDAM6 have recently been suggested to be involved in terminal bud dormancy. In this study, seasonal expression analyses using leaves, stems, and lateral buds of high-chill and low-chill peaches in field conditions indicated that both genes were up-regulated during the endodormancy period and down-regulated with endodormancy release. Controlled environment experiments showed that the expression of both PpDAM5 and PpDAM6 were up-regulated by ambient cool temperatures in autumn, while they were down-regulated by the prolonged period of cold temperatures in winter. A negative correlation between expression levels of PpDAM5 and PpDAM6 and bud burst percentage was found in the prolonged cold temperature treatment. Application of the dormancy-breaking reagent cyanamide to endo/ecodormant lateral buds induced early bud break and down-regulation of PpDAM5 and PpDAM6 expression at the same time. These results collectively suggest that PpDAM5 and PpDAM6 may function in the chilling requirement of peach lateral buds through growth-inhibiting functions for bud break. PMID:21378115

Yamane, Hisayo; Ooka, Tomomi; Jotatsu, Hiroaki; Hosaka, Yukari; Sasaki, Ryuta; Tao, Ryutaro

2011-01-01

41

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from

Mushtaq Ahmed; John H. Anderson; Earl R. Berry; Fred Brent; Ming He; Jimmy O. Ong; Mike K. Porter; Randy Roberts; Charles H. Schrader; Lalit S. Shah; Kenneth A. Yackly

2002-01-01

42

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using petroleum coke and ChevronTexaco's proprietary gasification technology. The objective of Phase I was to determine the

Randy Roberts

2003-01-01

43

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine

John Anderson; Mark Anselmo; Earl Berry; Mark Bohn; Ming He; Charles H. Schrader; Lalit Shah; Donald Todd; Robert Schavey

2004-01-01

44

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The 1999 U. S. Department of Energy (DOE) award to Texaco Energy Systems Inc. (presently Texaco Energy Systems LLC, a subsidiary of ChevronTexaco) was made to provide a Preliminary Engineering Design of an Early Entrance Coproduction Plant (EECP). Since the award presentation, work has been undertaken to achieve an economical concept design that makes strides toward the DOE Vision 21

Charles Benham; Mark Bohn; John Anderson; Earl Berry; Fred Brent; Ming He; Randy Roberts; Lalit Shah; Marjan Roos

2003-01-01

45

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine

John Anderson; Mark Anselmo; Earl Berry; Mark Bohn; Roko Bujas; Ming He; Ken Kwik; Charles H. Schrader; Lalit Shah; Dennis Slater; Donald Todd; Don Wall

2003-01-01

46

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define

Abdalla H. Ali; John H. Anderson; Earl R. Berry; Charles H. Schrader; Lalit S. Shah

2003-01-01

47

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from

John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; Jimmy O. Ong; Sarah J. Patel; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Phil J. Shires; Rae Song

2000-01-01

48

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using

Mushtaq Ahmed; John H. Anderson; Earl R. Berry; Troy Raybold; Lalit S. Shah; Kenneth A. Yackly

2003-01-01

49

Early Entrance Coproduction Plant  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using

Mushtaq Ahmed; John H. Anderson; Earl R. Berry; Troy Raybold; Lalit S. Shah; Kenneth A. Yackly

2004-01-01

50

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using

Mushtaq Ahmed; John H. Anderson; Charles Benham; Earl R. Berry; Fred Brent; Ming He; Troy Raybold; Lalit S. Shah; Kenneth A. Yackly

2003-01-01

51

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from

Mushtaq Ahmed; John H. Anderson; Charles Benham; Earl R. Berry; Fred Brent; Belma Demirel; Ming He; Troy Raybold; Manuel E. Quintana; Lalit S. Shah; Kenneth A. Yackly

2003-01-01

52

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from

John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; Jimmy O. Ong; Sarah J. Patel; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Phil J. Shires; Rae Song

2001-01-01

53

Release of Apical Dominance in Potato Tuber Is Accompanied by Programmed Cell Death in the Apical Bud Meristem[C][W  

PubMed Central

Potato (Solanum tuberosum) tuber, a swollen underground stem, is used as a model system for the study of dormancy release and sprouting. Natural dormancy release, at room temperature, is initiated by tuber apical bud meristem (TAB-meristem) sprouting characterized by apical dominance (AD). Dormancy is shortened by treatments such as bromoethane (BE), which mimics the phenotype of dormancy release in cold storage by inducing early sprouting of several buds simultaneously. We studied the mechanisms governing TAB-meristem dominance release. TAB-meristem decapitation resulted in the development of increasing numbers of axillary buds with time in storage, suggesting the need for autonomous dormancy release of each bud prior to control by the apical bud. Hallmarks of programmed cell death (PCD) were identified in the TAB-meristems during normal growth, and these were more extensive when AD was lost following either extended cold storage or BE treatment. Hallmarks included DNA fragmentation, induced gene expression of vacuolar processing enzyme1 (VPE1), and elevated VPE activity. VPE1 protein was semipurified from BE-treated apical buds, and its endogenous activity was fully inhibited by a cysteinyl aspartate-specific protease-1-specific inhibitor N-Acetyl-Tyr-Val-Ala-Asp-CHO (Ac-YVAD-CHO). Transmission electron microscopy further revealed PCD-related structural alterations in the TAB-meristem of BE-treated tubers: a knob-like body in the vacuole, development of cytoplasmic vesicles, and budding-like nuclear segmentations. Treatment of tubers with BE and then VPE inhibitor induced faster growth and recovered AD in detached and nondetached apical buds, respectively. We hypothesize that PCD occurrence is associated with the weakening of tuber AD, allowing early sprouting of mature lateral buds. PMID:22362870

Teper-Bamnolker, Paula; Buskila, Yossi; Lopesco, Yael; Ben-Dor, Shifra; Saad, Inbal; Holdengreber, Vered; Belausov, Eduard; Zemach, Hanita; Ori, Naomi; Lers, Amnon; Eshel, Dani

2012-01-01

54

Experiences with dormancy in tardigrades  

Microsoft Academic Search

Tardigrades often colonise extreme habitats, in which they survive using both types of dormancy: quiescence and diapause. To- gether with nematodes and bdelloid rotifers, tardigrades are known to enter quiescence (with several forms of cryptobiosis: anhy- drobiosis, cryobiosis, anoxybiosis, osmobiosis) at any stage of their life cycle, from egg to adult. Entering anhydrobiosis, tardigrades contract their body into a so-called

Roberto BERTOLANI; Roberto GUIDETTI; K. Ingemar JÖNSSON; Tiziana ALTIERO; Deborah BOSCHINI; Lorena REBECCHI

2004-01-01

55

Detail of secondary entrance south of main entrance on east ...  

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

Detail of secondary entrance south of main entrance on east elevation; camera facing west. - Mare Island Naval Shipyard, Mechanics Shop, Waterfront Avenue, west side between A Street & Third Street, Vallejo, Solano County, CA

56

8. WEST ENTRANCE TO CATWALK LOOKING TOWARDS EASTERN ENTRANCE. STORAGE ...  

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

8. WEST ENTRANCE TO CATWALK LOOKING TOWARDS EASTERN ENTRANCE. STORAGE TANKS LOCATED BELOW CATWALK. - Rocky Mountain Arsenal, Tank House, Quadrant 1, approximately 1000 feet South of December Seventh Avenue; 2200 feet East of D Street, Commerce City, Adams County, CO

57

EARLY ENTRANCE COPRODUCTION PLANT  

Microsoft Academic Search

As part of the Department of Energy's (DOE) Gasification Technologies and Transportation Fuels and Chemicals programs, DOE and Texaco are partners through Cooperative Agreement DE-FC26-99FT40658 to determine the feasibility of developing, constructing and operating an Early Entrance Coproduction Plant (EECP). The overall objective of the project is the three-phase development of an EECP that produces at least one product from

John H. Anderson; William K. Davis; Thomas W. Sloop

2001-01-01

58

Effect of Three Species of Arbuscular Mycorrhiza on Bud Sprout and Ripening in Grapevine (Vitis vinifera L.) cv. Perlette  

Microsoft Academic Search

Investigations were carried out with grape cv. Perlette to assess the influence of arbuscular mycorrhiza (AM) on breaking bud dormancy, and hastening flowering, berry set and berry ripening. Eighteen year old vines of Perlette, having uniform vigour and growth, planted at 2.5 × 2.5 m and trained on a telephone system, were inoculated with three strains of AM namely Glomus

K. Usha; Rebecca Mathew; B. Singh

2005-01-01

59

Amer. J. Bot. 70(6): 912-915. 1983. HORMONAL REGULATION OF EPIPHYLLOUS BUD RELEASE AND  

E-print Network

to de- velop into plantlets, and presumably this was due to a block in the flow of a substance away from acid (GA). Other species of Bryophyllum normally de- Received for publication 19 July 1982; revision ac dormancy. Elongation of ex- cised epiphyllous buds of B. tubzflorum was stimulated by GA, but inhibited

Rieseberg, Loren

60

Transcript profiling of Paoenia ostii during artificial chilling induced dormancy release identifies activation of GA pathway and carbohydrate metabolism.  

PubMed

Endo-dormant flower buds must pass through a period of chilling to reinitiate growth and subsequent flowering, which is a major obstacle to the forcing culture of tree peony in winter. Customized cDNA microarray (8×15 K element) was used to investigate gene expression profiling in tree peony 'Feng Dan Bai' buds during 24 d chilling treatment at 0-4°C. According to the morphological changes after the whole plants were transferred to green house, endo-dormancy was released after 18 d chilling treatment, and prolonged chilling treatment increased bud break rate. Pearson correlation hierarchical clustering of sample groups was highly consistent with the dormancy transitions revealed by morphological changes. Totally 3,174 significantly differentially-expressed genes (P<0.05) were observed through endo-dormancy release process, of which the number of up-regulated (1,611) and that of down-regulated (1,563) was almost the same. Functional annotation of differentially-expressed genes revealed that cellular process, metabolic process, response to stimulus, regulation of biological process and development process were well-represented. Hierarchical clustering indicated that activation of genes involved in carbohydrate metabolism (Glycolysis, Citrate cycle and Pentose phosphate pathway), energy metabolism and cell growth. Based on the results of GO analysis, totally 51 probes presented in the microarray were associated with GA response and GA signaling pathway, and 22 of them were differently expressed. The expression profiles also revealed that the genes of GA biosynthesis, signaling and response involved in endo-dormancy release. We hypothesized that activation of GA pathway played a central role in the regulation of dormancy release in tree peony. PMID:23405132

Gai, Shupeng; Zhang, Yuxi; Liu, Chunying; Zhang, Yang; Zheng, Guosheng

2013-01-01

61

Transcript Profiling of Paoenia ostii during Artificial Chilling Induced Dormancy Release Identifies Activation of GA Pathway and Carbohydrate Metabolism  

PubMed Central

Endo-dormant flower buds must pass through a period of chilling to reinitiate growth and subsequent flowering, which is a major obstacle to the forcing culture of tree peony in winter. Customized cDNA microarray (8×15 K element) was used to investigate gene expression profiling in tree peony ‘Feng Dan Bai’ buds during 24 d chilling treatment at 0–4°C. According to the morphological changes after the whole plants were transferred to green house, endo-dormancy was released after 18 d chilling treatment, and prolonged chilling treatment increased bud break rate. Pearson correlation hierarchical clustering of sample groups was highly consistent with the dormancy transitions revealed by morphological changes. Totally 3,174 significantly differentially-expressed genes (P<0.05) were observed through endo-dormancy release process, of which the number of up-regulated (1,611) and that of down-regulated (1,563) was almost the same. Functional annotation of differentially-expressed genes revealed that cellular process, metabolic process, response to stimulus, regulation of biological process and development process were well-represented. Hierarchical clustering indicated that activation of genes involved in carbohydrate metabolism (Glycolysis, Citrate cycle and Pentose phosphate pathway), energy metabolism and cell growth. Based on the results of GO analysis, totally 51 probes presented in the microarray were associated with GA response and GA signaling pathway, and 22 of them were differently expressed. The expression profiles also revealed that the genes of GA biosynthesis, signaling and response involved in endo-dormancy release. We hypothesized that activation of GA pathway played a central role in the regulation of dormancy release in tree peony. PMID:23405132

Liu, Chunying; Zhang, Yang; Zheng, Guosheng

2013-01-01

62

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The object of phase 1 is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD and T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase 2 is to implement the work as outlined in the Phase 1 RD and T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase 3 is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site.

Chi M. Ho; Robert A. Battista; Ashok Anand; Kenneth Yackly

2003-07-22

63

Multiple risk reduction mechanisms: can dormancy substitute for dispersal?  

Microsoft Academic Search

In a spatiotemporally variable environment, plants use seed dispersal and dormancy to reduce risk. Intuition suggests that dormancy should be able to substitute for dispersal, so that dormancy will reduce the optimal mean dispersal distance, and previous theoretical studies using temporally uncorrelated environments have found this to be true. I show that in the presence of positive temporal correlations, dormancy

Robin E. Snyder

2006-01-01

64

UC Santa Cruz Main Entrance  

E-print Network

UC Santa Cruz West Entrance Em pire Grade Main Entrance HagarDrive Coolid geDrive P H ellerSt. Mission St. Bay St. Bay St. WesternDr. University of California Santa Cruz campus GlennCoolidgeDr. Water meters are posted regarding hours of enforcement. S T Campus shuttle stop Santa Cruz Metro bus stop

Wilmers, Chris

65

Modelling Kiwifruit Budbreak as a Function of Temperature and Bud Interactions  

PubMed Central

This paper presents two models of budbreak on canes of ‘Hayward’ kiwifruit (Actinidia deliciosa). A conventional ‘chill unit’ (CU) type model is compared with an alternative ‘loss of potential’ (LOP) approach, which assumes that the number of buds developing in spring depends on climate and node position?dependent bud?to?bud interactions that vary in duration and intensity. Both models describe how temperature, and application of a dormancy?breaking chemical, determine the overall amount of budbreak for whole canes. However, the LOP model does so by describing patterns of budbreak along canes. To do this, the cumulative influence of distal neighbours is assumed to cause a progressive fall in the capacity for bud development over the autumn–winter period, an influence that gets stronger as temperature rises. The LOP model also assumes that the rate of decline varies along the cane, as a function of some inherent bud property. These two factors mean that buds towards the base of the cane break less often under the suppressive influence of distal neighbours, while low temperature (‘chilling’) increases budbreak by diminishing the intensity of suppression relative to bud development rate. Under this scenario, dormancy?breaking chemicals (such as hydrogen cyanamide, HC) enhance budbreak by diminishing the duration of suppression. Models were calibrated using daily temperature series and budbreak proportion data from a multi?year regional survey, and were then tested against independent data sets. Both models were run from a fixed start date until the time budbreak was almost complete, or until a standard date. The fitted models described 87 % of variation in amount of budbreak due to site, year, HC and node position effects in the original data set. Results suggest that the correlation between chilling and the amount of budbreak can be interpreted as a population?based phenomenon based on interaction among buds. PMID:12102525

AUSTIN, P. T.; HALL, A. J.; SNELGAR, W. P.; CURRIE, M. J.

2002-01-01

66

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

Mushtaq Ahmed; John H. Anderson; Earl R. Berry; Fred Brent; Ming He; Jimmy O. Ong; Mike K. Porter; Randy Roberts; Charles H. Schrader; Lalit S. Shah; Kenneth A. Yackly

2002-11-22

67

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three-phase development of an Early Entrance Coproduction Plant (EECP) that produces at least one product from at least two of the following three categories: Electric power (or heat); Fuels; and Chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or some other carbonaceous feedstock, such as petroleum coke. The objective of Phase I was to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II. This objective has now been accomplished. A specific site, Motiva Refinery in Port Arthur, Texas, has been selected as the location best suited for the EECP. The accomplishments of Phase I are discussed in detail in this Phase I Concept Report. A RD and T Plan and a preliminary project financing plan have been developed and are submitted separately from this report.

John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; David Mintner; Wendy Moore; Jimmy O. Ong; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Kalapi D. Sheth; Phil J. Shires; Rae Song

2001-05-17

68

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing Plan (RD and T) for implementation in Phase II. The objective of Phase II is to implement the RD and T as outlined in the Phase I RD and T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information that will be needed to move the EECP forward to detailed design, construction, and operation by industry.

John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; Jimmy O. Ong; Sarah J. Patel; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Phil J. Shires; Rae Song

2001-02-15

69

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objectives of Phase I were to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The work performed under Phase II will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

Mushtaq Ahmed; John H. Anderson; Earl R. Berry; Troy Raybold; Lalit S. Shah; Kenneth A. Yackly

2003-12-16

70

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objectives of Phase I were to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

Mushtaq Ahmed; John H. Anderson; Charles Benham; Earl R. Berry; Fred Brent; Ming He; Troy Raybold; Lalit S. Shah; Kenneth A. Yackly

2003-09-09

71

Early Entrance Coproduction Plant  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objectives of Phase I were to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The work performed under Phase II will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

Mushtaq Ahmed; John H. Anderson; Earl R. Berry; Troy Raybold; Lalit S. Shah; Kenneth A. Yackly

2004-01-26

72

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD and T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

William K. Davis

2001-03-21

73

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objectives of Phase I were to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

Mushtaq Ahmed; John H. Anderson; Charles Benham; Earl R. Berry; Fred Brent; Belma Demirel; Ming He; Troy Raybold; Manuel E. Quintana; Lalit S. Shah; Kenneth A. Yackly

2003-06-09

74

RNAi in Budding Yeast  

E-print Network

RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi ...

Drinnenberg, Ines A.

75

RNAi in budding yeast.  

PubMed

RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi is present in other budding yeast species, including Saccharomyces castellii and Candida albicans. These species use noncanonical Dicer proteins to generate small interfering RNAs, which mostly correspond to transposable elements and Y' subtelomeric repeats. In S. castellii, RNAi mutants are viable but have excess Y' messenger RNA levels. In S. cerevisiae, introducing Dicer and Argonaute of S. castellii restores RNAi, and the reconstituted pathway silences endogenous retrotransposons. These results identify a previously unknown class of Dicer proteins, bring the tool of RNAi to the study of budding yeasts, and bring the tools of budding yeast to the study of RNAi. PMID:19745116

Drinnenberg, Ines A; Weinberg, David E; Xie, Kathleen T; Mower, Jeffrey P; Wolfe, Kenneth H; Fink, Gerald R; Bartel, David P

2009-10-23

76

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

As part of the Department of Energy's (DOE) Gasification Technologies and Transportation Fuels and Chemicals programs, DOE and Texaco are partners through Cooperative Agreement DE-FC26-99FT40658 to determine the feasibility of developing, constructing and operating an Early Entrance Coproduction Plant (EECP). The overall objective of the project is the three-phase development of an EECP that produces at least one product from at least two of the following three categories: Electric power (or heat); Fuels; and Chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or some other carbonaceous feedstock, such as petroleum coke. The objective of Phase I was to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II. This objective has now been accomplished. A specific site, Motiva Refinery in Port Arthur, Texas, has been selected as the location best suited for the EECP. The specific work requirements of Phase I included: Prepare an EECP Preliminary Concept Report covering Tasks 2-8 specified in the Cooperative Agreement; Develop a Research, Development, and Testing (RD and T) Plan as specified in Task 9 of the Cooperative Agreement for implementation in Phase II; and Develop a Preliminary Project Financing Plan for the EECP Project as specified in Task 10 of the Cooperative Agreement. This document is the Preliminary Project Financing Plan for the design, construction, and operation of the EECP at the Motiva Port Arthur Refinery.

John H. Anderson; William K. Davis; Thomas W. Sloop

2001-03-21

77

Seed dormancy distribution: explanatory ecological factors  

PubMed Central

Background and Aims Knowledge of those traits that vary with latitude should be helpful in predicting how they may evolve locally under climate change. In the sea beet Beta vulgaris ssp. maritima, seed dormancy largely controls the timing of germination, is highly heritable and varies geographically; it is therefore thought to be selected by climate. The aim here was to characterize the variation in seed dormancy among sea beet populations across the French distribution area, as well as the ecological factors in situ that are correlated with and that could therefore select for seed dormancy. The relative importance of genetic inheritance vs. non-genetic variation is also evaluated. Methods The proportions of dormant seeds from 85 natural populations encompassing different climates over the whole French distribution area were measured under controlled conditions. Germination phenology was observed in a common garden experiment. Dormancy variation of seeds collected in situ was compared with that of seeds collected on plants grown in the greenhouse. Key Results The proportions of dormant seeds in the greenhouse were highly variable, covering almost the entire range from 0 to 1, and followed a geographical pattern from lower dormancy at high latitudes to high dormancy at low latitudes. The distribution of dormancy was positively correlated with yearly temperatures, especially summer temperatures. Minimum temperatures in winter did not significantly explain the trait variation. The genetic component of the total variation was significant and is probably completed by an important adjustment to the local conditions brought about by maternal adaptive phenotypic plasticity. Conclusions Dormancy in sea beet could be interpreted as a way to limit summer germination and spread germination over the first autumn and spring or following autumns. This highly heritable trait has the potential to evolve in the relatively near future because of climate change. PMID:22952378

Wagmann, Kristen; Hautekèete, Nina-Coralie; Piquot, Yves; Meunier, Cécile; Schmitt, S. Eric; Van Dijk, Henk

2012-01-01

78

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

In 1999, the U. S. Department of Energy (DOE) awarded a Cooperative Agreement to Texaco Energy Systems Inc. to provide a preliminary engineering design of an Early Entrance Coproduction Plant (EECP). Since the award, continuous and diligent work has been undertaken to achieve the design of an economical facility that makes strides toward attaining the goal of DOE's Vision 21 Program. The objective of the EECP is to convert coal and/or petroleum coke to power while coproducing transportation fuels, chemicals, and useful utilities such as steam. This objective is being pursued in a three-phase effort through the partnership of the DOE with prime contractor Texaco Energy Systems, LLC. (TES), the successor to Texaco Energy Systems, Inc. The key subcontractors to TES include General Electric (GE), Praxair, and Kellogg Brown and Root. ChevronTexaco provided gasification technology and Rentech Inc.'s Fischer-Tropsch (F-T) technology that has been developed for non-natural gas sources. GE provided gas turbine technology for the combustion of low energy content gas. Praxair provided air separation technology and KBR provided engineering to integrate the facility. A conceptual design was completed in Phase I and the report was accepted by the DOE in May 2001. The Phase I work identified risks and critical research, development, and testing that would improve the probability of technical success of the EECP. The objective of Phase II was to mitigate the risks by executing research, development, and testing. Results from the Phase II work are the subject of this report. As the work of Phase II concluded, it became evident that sufficient, but not necessarily complete, technical information and data would be available to begin Phase III - Preliminary Engineering Design. Work in Phase II requires additional technical development work to correctly apply technology at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The decision to proceed with Phase III centers on locating a new site and favorable commercial and economic factors.

John Anderson; Charles Schrader

2004-01-26

79

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, Inc., GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. During Phase I, a design basis for the Fischer-Tropsch Synthesis section was developed based on limited experience with the specified feed gas and operating conditions. The objective of this Task in Phase II RD&T work was to confirm the performance of the F-T reactor at the set design conditions. Although much of the research, development, and testing work were done by TES outside of this project, several important issues were addressed in this phase of the project. They included Rejuvenation/Regeneration of the Fischer-Tropsch Catalyst, online Catalyst Withdrawal and Addition from the synthesis reactor, and the Fischer-Tropsch Design Basis Confirmation. In Phase III the results from these RD&T work will be incorporated in developing the engineering design package. This Topical Report documents the Phase II RD&T work that was completed for this task.

David Storm; Govanon Nongbri; Steve Decanio; Ming He; Lalit Shah; Charles Schrader; Earl Berry; Peter Ricci; Belma Demirel; Charles Benham; Mark Bohn

2004-01-12

80

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems was assessed for technical risks and barriers. A plan was developed to mitigate the identified risks (Phase II RD&T Plan, October 2000). The potential technical and economic risks to the EECP from Task 2.5 can be mitigated by demonstrating that the end-use products derived from the upgrading of the F-T synthesis total liquid product can meet or exceed current specifications for the manufacture of ethylene and propylene chemicals from F-T naphtha, for the generation of hydrogen from F-T naphtha to power fuel cells, for direct blending of F-T diesels into transportation fuels, for the conversion of F-T heavy product wax to transportation fuels, and the conversion of F-T Heavy product wax to a valuable high melting point food-grade specialty wax product. Product evaluations conducted under Task 2.5 of Phase II successfully mitigated the above technical and economic risks to the EECP with the development of product yields and product qualities for the production of chemicals, transportation fuels, and specialty food-grade waxes from the F-T synthesis products.

Fred D. Brent; Lalit Shah; Earl Berry; Charles H. Schrader; John Anderson; Ming He; James F. Stevens; Centha A. Davis; Michael Henley; Jerome Mayer; Harry Tsang; Jimell Erwin; Jennifer Adams; Michael Tillman; Chris Taylor; Marjan J. Roos; Robert F. Earhart

2004-01-27

81

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. During Phase I the team identified several potential methods to reduce or minimize the environmental impact of the proposed EECP. The EECP Project Team identified F-T catalyst disposal, beneficial gasifier slag usage (other than landfill), and carbon dioxide recovery for the gas turbine exhaust for study under this task. Successfully completing the Task 2.10 RD&T provides additional opportunities for the EECP to meet the goals of DOE's Vision 21 Program. The gasification section offers several opportunities to maximize the environmental benefits of an EECP. The spent F-T catalyst can be sent to landfills or to the gasification section. Testing in Phase II shows that the spent F-T catalyst with a small wax coating can safely meet federal landfill requirements. As an alternative to landfilling, it has been proposed to mix the spent F-T catalyst with the petroleum coke and feed this mixture to the gasification unit. Based on ChevronTexaco's experience with gasification and the characteristics of the spent F-T catalyst this appears to be an excellent opportunity to reduce one potential waste stream. The slag from the gasification unit can be commercially marketed for construction or fuel (such as cement kiln fuel) uses. The technical and economic benefits of these options must be reviewed for the final EECP before incorporating a specific alternative into the design basis. Reducing greenhouse gas emissions, particularly carbon dioxide, is an important goal of the EECP. The Texaco gasification process provides opportunities to capture high purity streams of carbon dioxide. For Phase II, a carbon fiber composite molecular sieve (CFCMS) was tested to determine its potential to remove high purity carbon dioxide from the exhaust of a gas turbine. Testing on with a simulated gas turbine exhaust shows that the CFCMS is able to remove high purity carbon dioxide from the exhaust. However, more development is required to optimize the system.

John H. Anderson; Charles Benham; Earl R. Berry; Ming He; Charles H. Schrader; Lalit S. Shah; O.O. Omatete; T.D. Burchell

2004-01-12

82

EARLY ENTRANCE COPRODUCTION PLANT  

SciTech Connect

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. During Phase I the team identified the integration of the water produced in the F-T synthesis section with the gasification section as an area of potential synergy. By utilizing the F-T water in the petroleum coke slurry for the gasifier, the EECP can eliminate a potential waste stream and reduce capital costs. There is a low technical risk for this synergy, however, the economic risk, particularly in regards to the water, can be high. The economic costs include the costs of treating the water to meet the locally applicable environmental standards. This option may require expensive chemicals and treatment facilities. EECP Phase II included tests conducted to confirm the viability of integrating F-T water in the slurry feed for the gasifier. Testing conducted at ChevronTexaco's Montebello Technology Center (MTC) included preparing slurries made using petroleum coke with F-T water collected at the LaPorte Alternative Fuels Development Unit (AFDU). The work included bench scale tests to determine the slurry ability of the petroleum coke and F-T water. The results of the tests show that F-T water does not adversely affect slurries for the gasifier. There are a few cases where in fact the addition of F-T water caused favorable changes in viscosity of the slurries. This RD&T task was executed in Phase II and results are reported herein.

Abdalla H. Ali; Raj Kamarthi; John H. Anderson; Earl R. Berry; Charles H. Schrader; Lalit S. Shah

2003-04-16

83

Making an Entrance. Teaching Art with Art.  

ERIC Educational Resources Information Center

Provides a discussion on entrance designs to interest students in the history of architecture. Focuses on reasons why studying entrances is important. Includes pictures of four different entrances to show students the diversity of entrances and offer examples to give student ideas for their work. (CMK)

Hubbard, Guy

2001-01-01

84

Tansley review Seed dormancy and the control of germination  

E-print Network

Tansley review Seed dormancy and the control of germination William E. Finch-Savage1 and Gerhard This section on applied aspects of the control of seed germination by dormancy is an additional part the seed at the molecular level? 5. Applied aspects of the control of germination by seed dormancy Seeds

Leubner, Gerhard

85

On dormancy strategies in tardigrades.  

PubMed

In this review we analyze the dormancy strategies of metazoans inhabiting "hostile to life" habitats, which have a strong impact on their ecology and in particular on the traits of their life history. Tardigrades are here considered a model animal, being aquatic organisms colonizing terrestrial habitats. Tardigrades evolved a large variety of dormant stages that can be ascribed to diapause (encystment, cyclomorphosis, resting eggs) and cryptobiosis (anhydrobiosis, cryobiosis, anoxibiosis). In tardigrades, diapause and cryptobiosis can occur separately or simultaneously, consequently the adoption of one adaptive strategy is not necessarily an alternative to the adoption of the other. Encystment and cyclomorphosis are characterized by seasonal cyclic changes in morphology and physiology of the animals. They share several common features and their evolution is strictly linked to the molting process. A bet-hedging strategy with different patterns of egg hatching time has been observed in a tardigrade species. Four categories of eggs have been identified: subitaneous, delayed-hatching, abortive and diapause resting eggs, which needs a stimulus to hatch (rehydration after a period of desiccation). Cryptobiotic tardigrades are able to withstand desiccation (anhydrobiosis) and freezing (cryobiosis) at any stage of their life-cycle. This ability involves a complex array of factors working at molecular (bioprotectans), physiological and structural levels. Animal survival and the accumulation of molecular damage are related to the time spent in the cryptobiotic state, to the abiotic parameters during the cryptobiotic state, and to the conditions during initial and final phases of the process. Cryptobiosis evolved independently at least two times in tardigrades, in eutardigrades and in echiniscoids. Within each evolutionary line, the absence of cryptobiotic abilities is more related to selective pressures to local habitat adaptation than to phylogenetic relationships. The selective advantages of cryptobiosis (e.g. persistency in "hostile to life" habitats, reduction of competitors, parasites and predators, escaping in time from stressful conditions) could explain the high tardigrade species diversity and number of specimens found in habitats that dry out compared to freshwater habitats. PMID:21402076

Guidetti, Roberto; Altiero, Tiziana; Rebecchi, Lorena

2011-05-01

86

Identification and analysis of phosphorylation status of proteins in dormant terminal buds of poplar  

PubMed Central

Background Although there has been considerable progress made towards understanding the molecular mechanisms of bud dormancy, the roles of protein phosphorylation in the process of dormancy regulation in woody plants remain unclear. Results We used mass spectrometry combined with TiO2 phosphopeptide-enrichment strategies to investigate the phosphoproteome of dormant terminal buds (DTBs) in poplar (Populus simonii × P. nigra). There were 161 unique phosphorylated sites in 161 phosphopeptides from 151 proteins; 141 proteins have orthologs in Arabidopsis, and 10 proteins are unique to poplar. Only 34 sites in proteins in poplar did not match well with the equivalent phosphorylation sites of their orthologs in Arabidopsis, indicating that regulatory mechanisms are well conserved between poplar and Arabidopsis. Further functional classifications showed that most of these phosphoproteins were involved in binding and catalytic activity. Extraction of the phosphorylation motif using Motif-X indicated that proline-directed kinases are a major kinase group involved in protein phosphorylation in dormant poplar tissues. Conclusions This study provides evidence about the significance of protein phosphorylation during dormancy, and will be useful for similar studies on other woody plants. PMID:22074553

2011-01-01

87

Clove bud oil: an efficient, economical and widely available oil for the inhibition of wheat seed germination  

Microsoft Academic Search

Pre-harvest sprouting refers to the precocious germination of the grain in the spike prior to harvest as a result of moist\\u000a weather conditions at harvest time. From the agricultural viewpoint, it is necessary to impose an exogenous dormancy to wheat\\u000a seeds in order to improve the resistance of seed to pre-harvest sprouting. In this regard, we found that clove bud

Hossein Reza Darabi; Shabnam Mohandessi; Yadollah Balavar; Mojtaba Mirhosseini Moghaddam; Kioumars Aghapoor; Farshid Mohsenzadeh; Abbas Ali Nourinia

88

Subtractive cDNA Libraries Identify Differentially Expressed Genes in Dormant and Growing Buds of Leafy Spurge ( Euphorbia esula )  

Microsoft Academic Search

Two subtractive cDNA libraries were developed to study genes associated with bud dormancy (reverse library) and initiation\\u000a of shoot growth (forward library) in leafy spurge. To identify unique sequences represented in each library, 15744 clones\\u000a were screened to reduce the level of redundancy within both libraries. A total of 516 unique sequences were obtained from\\u000a 2304 minimally redundant clones. Radioactive

Ying Jia; James V. Anderson; David P. Horvath; Yong-Qiang Gu; Rodney G. Lym; Wun S. Chao

2006-01-01

89

South Entrance North Reading Room  

E-print Network

South Entrance FLOOR 2 North Reading Room Heyns Reading Room Current Periodicals Rosberg Reading 251 M Dissertation Writers' Room Reference Desk 215 Current Periodicals FLOOR 2 North Reading Room Heyns Reading Room Current Periodicals Rosberg Reading Room Graduate Services 212 218 Reference Hall

Walker, Matthew P.

90

(Construction entrance only) intramural fields  

E-print Network

(visitors, faculty, staff) rice boulevard track/soccer stadium reckling park jake hess tennis stadium tennis............... 67 Building Track and Soccer Stadium...................... 68 Tudor Fieldhouse for Physics Site of South Colleges Renovation and Addition Rice University Campus Map Entrance Gates Visitor's

Richards-Kortum, Rebecca

91

UC Santa Cruz Main Entrance  

E-print Network

COFFEE SHOP PAGE SMITH LIBRARY RR RR RR RR COWELL/STEVENSON MAIN ENTRANCE COLLEGE OFFICE DINING COMMONS The Eloise Pickard Smith Gallery is located in Cowell College, in the southeast corner of the campus coreLaughlin Drive, turn left at the second opportunity, following the sign for Cowell College. There are several

Wilmers, Chris

92

Does tumour dormancy offer a therapeutic target?  

Microsoft Academic Search

The increasing number of cancer survivors is cause for celebration, but this expanding population has highlighted the problem of tumour dormancy, which can lead to relapse. As we start to understand more about the biology of dormant cancer cells, we can begin to address how best to treat this form of disease. Preclinical models and initial clinical trials, as exemplified

Paul E. Goss; Ann F. Chambers

2010-01-01

93

Seed Dormancy in Red Rice 1  

PubMed Central

The weak acid character of many previously identified, but otherwise chemically dissimilar, dormancy-breaking compounds may contribute to their physiological activity. To test this idea, short chain monocarboxylic acids of one to six carbons, for which no previous reports of such activity exist, were incubated with dormant, dehulled red rice (Oryza sativa) seeds. Greater than 90% germination was observed after 24 hours of imbibition with 19 millimolar formic, 53 millimolar acetic, 20 millimolar propionic, 28 millimolar butyric, 20 millimolar valeric, or 16 millimolar caproic acid followed by 7 to 14 days incubation on water at 30°C. Dormancy-breaking activity was pH-dependent. Incubation medium pH values that favored formation of the protonated species resulted in the highest germination percentages. There was no promotive effect of medium pH itself in the range of 3 to 7. In contrast, germination of intact seeds was less than 40% in the presence of 55 millimolar monocarboxylic acids at pH 3, unless seeds were partially dry-afterripened. The pH-dependent activity of these acids was maintained during afterripening of intact seeds. The results are consistent with the idea that the dissociable proton of weak acids is responsible for their dormancy-breaking activity. Many other weak acids may break seed dormancy but have been over-looked due to the rigid pH dependence necessary for activity. PMID:16665509

Cohn, Marc Alan; Chiles, Lisa A.; Hughes, John A.; Boullion, Karen J.

1987-01-01

94

Increase in ACC oxidase levels and activities during paradormancy release of leafy spurge (Euphorbia esula) buds.  

PubMed

The plant hormone ethylene is known to affect various developmental processes including dormancy and growth. Yet, little information is available about the role of ethylene during paradormancy release in underground adventitious buds of leafy spurge. In this study, we examined changes in ethylene evolution and the ethylene biosynthetic enzyme ACC oxidase following paradormancy release (growth induction). Our results did not show an obvious increase in ethylene during bud growth. However, when buds were incubated with 1 mM ACC, ethylene levels were higher in growing than non-growing buds, suggesting that the levels of ACC oxidase increased in growing buds. Real-time qPCR indicated that the transcript of a Euphorbia esula ACC oxidase (Ee-ACO) increased up to threefold following growth induction. In addition, a 2.5- to 4-fold increase in ACO activity was observed 4 days after decapitation, and the Ee-ACO accounted for 40 % of the total ACO activity. Immunoblot analyses identified a 36-kD Ee-ACO protein that increased in expression during bud growth. This protein was highly expressed in leaves, moderately expressed in crown buds, stems and meristems, and weakly expressed in roots and flowers. Immunolocalization of Ee-ACO on growing bud sections revealed strong labeling of the nucleus and cytoplasm in cells at the shoot apical meristem and leaf primordia. An exception to this pattern occurred in cells undergoing mitosis, where labeling of Ee-ACO was negligible. Taken together, our results indicated an increase in the levels of Ee-ACO during paradormancy release of leafy spurge that was not correlated with an increase in ethylene synthesis. PMID:23625016

Chao, Wun S; Serpe, Marcelo; Suttle, Jeffrey C; Jia, Ying

2013-07-01

95

30 CFR 18.37 - Lead entrances.  

...2014-07-01 2014-07-01 false Lead entrances. 18.37 Section 18.37...Construction and Design Requirements § 18.37 Lead entrances. (a) Insulated cable...enclosure, shall pass through a stuffing-box lead entrance. All sharp edges that...

2014-07-01

96

Main Entrances Free City Bus Stops  

E-print Network

647 EASBY ROAD A647 A647 25 26 27 B Main Entrances Free City Bus Stops Controlled parking areas Information B Bus Stops B Main Entrances Free City Bus Stops Controlled parking areas (permit holders only B Main Entrances Free City Bus Stops Controlled parking areas (permit holders only)P Visitor car

Magee, Derek

97

Proteomic approach to analyze dormancy breaking of tree seeds.  

PubMed

In forest broadleaves from the temperate zone, a large number of species exhibit seed dormancy phenomena. Tree seeds show some of the most pronounced and complicated forms of dormancy in the plant kingdom. Many seeds are deeply physiologically dormant whatever their moisture level and age. However, dormancy can usually be overcome by a cold or warm stratification for several months. The transition from seed dormancy to germination is a multi-step process. In combination with the availability of genome sequence data, proteomics has opened up enormous possibilities for identifying the total set of expressed proteins as well as expression changes during dormancy breaking. The proteomic approach used for analysis of dormancy breaking of tree seeds offers new data allowing better understanding of the mechanism of deep physiological dormancy. The results of proteomic studies on dormancy breaking and the presence of abscisic and gibberellic acids in tree seeds (beech Fagus sylvatica L., Norway maple Acer platanoides L. and sycamore Acer pseudoplatanus L.), help to explain this process better. Most of the changes in protein expression were observed at the end of stratification and in the germinated seeds. This is the most active period of dormancy breaking when seeds pass from the quiescent state to germination. The analysis of the proteins' function showed that the mechanism of seed dormancy breaking involves many processes. Energy metabolism, proteasome, transcription, protein synthesis, signal transduction and methionine metabolism proteins have a special importance. PMID:20306286

Paw?owski, Tomasz Andrzej

2010-05-01

98

Colon Cryptogenesis: Asymmetric Budding  

PubMed Central

The process of crypt formation and the roles of Wnt and cell-cell adhesion signaling in cryptogenesis are not well described; but are important to the understanding of both normal and cancer colon crypt biology. A quantitative 3D-microscopy and image analysis technique is used to study the frequency, morphology and molecular topography associated with crypt formation. Measurements along the colon reveal the details of crypt formation and some key underlying biochemical signals regulating normal colon biology. Our measurements revealed an asymmetrical crypt budding process, contrary to the previously reported symmetrical fission of crypts. 3D immunofluorescence analyses reveals heterogeneity in the subcellular distribution of E-cadherin and ?-catenin in distinct crypt populations. This heterogeneity was also found in asymmetrical budding crypts. Singular crypt formation (i.e. no multiple new crypts forming from one parent crypt) were observed in crypts isolated from the normal colon mucosa, suggestive of a singular constraint mechanism to prevent aberrant crypt production. The technique presented improves our understanding of cryptogenesis and suggests that excess colon crypt formation occurs when Wnt signaling is perturbed (e.g. by truncation of adenomatous polyposis coli, APC protein) in most colon cancers. PMID:24205248

Tan, Chin Wee; Hirokawa, Yumiko; Gardiner, Bruce S.; Smith, David W.; Burgess, Antony W.

2013-01-01

99

Colon cryptogenesis: asymmetric budding.  

PubMed

The process of crypt formation and the roles of Wnt and cell-cell adhesion signaling in cryptogenesis are not well described; but are important to the understanding of both normal and cancer colon crypt biology. A quantitative 3D-microscopy and image analysis technique is used to study the frequency, morphology and molecular topography associated with crypt formation. Measurements along the colon reveal the details of crypt formation and some key underlying biochemical signals regulating normal colon biology. Our measurements revealed an asymmetrical crypt budding process, contrary to the previously reported symmetrical fission of crypts. 3D immunofluorescence analyses reveals heterogeneity in the subcellular distribution of E-cadherin and ?-catenin in distinct crypt populations. This heterogeneity was also found in asymmetrical budding crypts. Singular crypt formation (i.e. no multiple new crypts forming from one parent crypt) were observed in crypts isolated from the normal colon mucosa, suggestive of a singular constraint mechanism to prevent aberrant crypt production. The technique presented improves our understanding of cryptogenesis and suggests that excess colon crypt formation occurs when Wnt signaling is perturbed (e.g. by truncation of adenomatous polyposis coli, APC protein) in most colon cancers. PMID:24205248

Tan, Chin Wee; Hirokawa, Yumiko; Gardiner, Bruce S; Smith, David W; Burgess, Antony W

2013-01-01

100

PtABI3 impinges on the growth and differentiation of embryonic leaves during bud set in poplar.  

PubMed

The Arabidopsis ABSCISIC ACID-INSENSITIVE3 (ABI3) protein plays a crucial role during late seed development and has an additional function at the vegetative meristem, particularly during periods of growth-arresting conditions and quiescence. Here, we show that the ABI3 homolog of poplar (PtABI3) is expressed in buds during natural bud set. Expression occurs clearly after perception of the critical daylength that initiates bud set and dormancy in poplar. In short-day conditions mimicking natural bud set, the expression of a chimeric PtABI3::beta-glucuronidase (GUS) gene occurred in those organs and cells of the apex that grow actively but will undergo arrest: the young embryonic leaves, the subapical meristem, and the procambial strands. If PtABI3 is overexpressed or downregulated, bud development in short-day conditions is altered. Constitutive overexpression of PtABI3 resulted in apical buds with large embryonic leaves and small stipules, whereas in antisense lines, bud scales were large and leaves were small. Thus, PtABI3 influences the size and ratio of embryonic leaves and bud scales/stipules that differentiate from the primordia under short-day conditions. These observations, together with the expression of PtABI3::GUS in embryonic leaves but not in bud scales/stipules, support the idea that wild-type PtABI3 is required for the relative growth rate and differentiation of embryonic leaves inside the bud. These experiments reveal that ABI3 plays a role in the cellular differentiation of vegetative tissues, in addition to its function in seeds. PMID:12172029

Rohde, Antje; Prinsen, Els; De Rycke, Riet; Engler, Gilbert; Van Montagu, Marc; Boerjan, Wout

2002-08-01

101

Effect of Growth Regulators on CO2 Assimilation in Leaves, and its Correlation with the Bud Break Response in Photosynthesis 1  

PubMed Central

Experiments have been done to confirm the previously reported effect of indoleacetic acid (IAA) on the rate of CO2 assimilation in bean leaves. It was shown that spraying the leaves of a variety of plants caused an increase in the rate of CO2 assimilation from 30% to 100% during the half-hour to 1 hour period following spraying. The only plant tested which did not show such an effect was corn. The breaking of dormancy of axial buds in the bean plant was correlated with an increase in the rate of CO2 assimilation in adjacent leaves for a brief period of time. It has been shown that IAA solution sprayed on 1 leaflet of a leaf can cause an increase in the rate of CO2 assimilation in the other leaflets, and that IAA applied to the cut stem of a leaflet or a developing bud can be transported to adjacent leaves and cause an increase in the CO2 assimilation rate. The reaction caused by IAA is very similar to that caused by the breaking of dormancy of a bud. This indicates that the bud break response in CO2 assimilation in leaves is caused by auxin synthesized in a bud as it begins to grow, and exported into adjacent leaves. PMID:16656249

Bidwell, R. G. S.; Turner, Wendy B.

1966-01-01

102

Fiber Optic Entrance Links For Electric Utilities  

NASA Astrophysics Data System (ADS)

This paper discusses the installation of a fiber optic entrance link in operation for nearly one year at Alabama Power Company's Barry Generating Plant. Optical and electronics selection and installation of this system are shown to be straightforward and trouble-free. The reasons why optical entrance links are the first electrical utility application to become technically and economically practical are reviewed. An economic analysis compares optical entrance link systems with conventional protection systems. This analysis shows that fiber optic entrance links should be used in the majority of future utility installations.

Fairaizl, Alan F.; Engineer, Carl P.

1980-09-01

103

INVITED REVIEW Plant hormone interactions during seed dormancy release  

E-print Network

dormancy, promotes germination and coun- teracts ABA effects. Ethylene and BR promote seed germination and also counteract ABA effects. We present an integrated view of the molecular genetics, physiology-limited germination, ethylene, gibberellin, hormone mutants, Nicotiana, seed dormancy, seed germination, signal

Leubner, Gerhard

104

Phases of Dormancy in Yam Tubers (Dioscorea rotundata)  

Microsoft Academic Search

Background and Aims The control of dormancy in yam (Disocorea spp.) tubers is poorly understood and attempts to shorten the long dormant period (i.e. cause tubers to sprout or germinate much earlier) have been unsuccessful. The aim of this study was to identify and define the phases of dormancy in Dioscorea rotundata tubers, and to produce a framework within which

E. I. ILE; P. Q. CRAUFURD; N. H. BATTEY; R. ASIEDU

2006-01-01

105

Seed dormancy and germination--emerging mechanisms and new hypotheses  

PubMed Central

Seed dormancy has played a significant role in adaptation and evolution of seed plants. While its biological significance is clear, molecular mechanisms underlying seed dormancy induction, maintenance and alleviation still remain elusive. Intensive efforts have been made to investigate gibberellin and abscisic acid metabolism in seeds, which greatly contributed to the current understanding of seed dormancy mechanisms. Other mechanisms, which might be independent of hormones, or specific to the seed dormancy pathway, are also emerging from genetic analysis of “seed dormancy mutants.” These studies suggest that chromatin remodeling through histone ubiquitination, methylation and acetylation, which could lead to transcription elongation or gene silencing, may play a significant role in seed dormancy regulation. Small interfering RNA and/or long non-coding RNA might be a trigger of epigenetic changes at the seed dormancy or germination loci, such as DELAY OF GERMINATION1. While new mechanisms are emerging from genetic studies of seed dormancy, novel hypotheses are also generated from seed germination studies with high throughput gene expression analysis. Recent studies on tissue-specific gene expression in tomato and Arabidopsis seeds, which suggested possible “mechanosensing” in the regulatory mechanisms, advanced our understanding of embryo-endosperm interaction and have potential to re-draw the traditional hypotheses or integrate them into a comprehensive scheme. The progress in basic seed science will enable knowledge translation, another frontier of research to be expanded for food and fuel production. PMID:24904627

Nonogaki, Hiroyuki

2014-01-01

106

7. WALKWAY/ENTRANCE TO ADMINSITRATIVE SITE ADJACENT TO ENTRANCE ROAD AND ...  

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

7. WALKWAY/ENTRANCE TO ADMINSITRATIVE SITE ADJACENT TO ENTRANCE ROAD AND INTERNAL POLICE POST, LOOKING SOUTHEAST - Manzanar War Relocation Center, Owens Valley off U.S. Highway 395, 6 miles South of Independence, Independence, Inyo County, CA

107

Presynaptically silent synapses: dormancy and awakening of presynaptic vesicle release.  

PubMed

Synapses represent the main junctures of communication between neurons in the nervous system. In many neurotransmitter systems, a fraction of presynaptic terminals fails to release vesicles in response to action potential stimulation and strong calcium influx. These silent presynaptic terminals exhibit a reversible functional dormancy beyond low vesicle release probability, and dormancy status may have important implications in neural function. Recent advances have implicated presynaptic proteins interacting with vesicles downstream of cAMP and protein kinase A signaling cascades in modulating the number of these mute presynaptic terminals, and dormancy induction may represent a homeostatic neuroprotective mechanism active during pathological insults involving excitotoxicity. Interestingly, dormancy reversal may also be induced during Hebbian plasticity. Here, details of synaptic dormancy, recent insights into the molecular signaling cascades involved, and potential clinical and mechanistic implications of this form of synaptic plasticity are described. PMID:21908849

Crawford, Devon C; Mennerick, Steven

2012-06-01

108

"PROBATION AT ENTRANCE"--A STUDY.  

ERIC Educational Resources Information Center

PERSISTENCY AND SUCCESS OF 200 FALL, 1962, "PROBATION AT ENTRANCE" STUDENTS (WITH LESS THAN 2.0 GRADE POINT AVERAGE) WAS STUDIED. PERCENTAGE OF MEN AND WOMEN FROM VARIOUS HIGH SCHOOLS, MEDIAN ENTRANCE TEST SCORES, MAJOR FIELDS CHOSEN, AND EXTRACURRICULAR ACTIVITIES WERE ENUMERATED. THE MAJORITY OF STUDENTS CHOSE GOALS WITHIN THEIR ABILITY LEVELS,…

LUKE, ORRAL S.

109

Kindergarten Entrance Age and Academic Achievement.  

ERIC Educational Resources Information Center

The practice of delaying students' entrance into kindergarten raises several questions. This literature review asks: (1) How does the entrance age of kindergarten children affect academic achievement?; (2) Do age-eligible older students perform better academically than younger students?; (3) Do year-older or "red-shirted" students have an academic…

Narahara, May

110

PennAccess: Levine Hall Entrance Information  

E-print Network

PennAccess: Levine Hall Entrance Information: 200 South 33rd Street . Philadelphia . PA . 19104 1. Levine Hall is accessible through the main entrance on Walnut Street. There is a hallway which leads. 3. Levine Hall may also be accessed through the Skirkanich Hall entry off 33rd Street. Elevator

Plotkin, Joshua B.

111

Candidate cave entrances on Mars  

USGS Publications Warehouse

This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

Cushing, Glen E.

2012-01-01

112

Subtractive cDNA libraries identify differentially expressed genes in dormant and growing buds of leafy spurge (Euphorbia esula).  

PubMed

Two subtractive cDNA libraries were developed to study genes associated with bud dormancy (reverse library) and initiation of shoot growth (forward library) in leafy spurge. To identify unique sequences represented in each library, 15744 clones were screened to reduce the level of redundancy within both libraries. A total of 516 unique sequences were obtained from 2304 minimally redundant clones. Radioactive probes developed from RNAs extracted from crown buds of either intact (para-dormant control) or a series of growth-induced (2 h, 2, and 4 d after decapitation) plants were used to identify differentially expressed genes by macroarray analysis. Semi-quantitative RT-PCR was used to confirm results obtained by macroarray analysis and to determine the expression profiles for other transcripts identified within the subtractive libraries. Selected clones were also used to examine gene expression in crown buds after growth induction and/or during normal seasonal growth. In this study, four distinct patterns of gene expression were observed during the transition from para-dormancy to growth-induction. Many of the differentially regulated genes identified have unknown or hypothetical functions while others are known to play important roles in molecular functions. Gene ontology analysis identified a greater proportion of genes involved with catalytic activity in the forward library while the reverse library had a greater proportion of genes involved in DNA/RNA binding. PMID:16786310

Jia, Ying; Anderson, James V; Horvath, David P; Gu, Yong-Qiang; Lym, Rodney G; Chao, Wun S

2006-05-01

113

Budding and fission of vesicles.  

PubMed Central

We report on budding and fission of protein-free vesicles swollen from a natural lipid mixture of bovine brain sphingomyelins. Budding was induced by increasing the area-to-volume ratio through heating. Morphological changes were monitored by phase contrast microscopy and correlated with the thermal behavior of the bilayer by differential scanning calorimetry. Freeze fracture electron microscopy revealed that budding and fission are not restricted to giant vesicles but also occur on length scales relevant for cellular processes. We also observed osmotically induced budding and fission in mixtures of dimyristoyl phosphatidylcholine with cholesterol. We find that these shape transitions are driven by liquid/gel domain formation and/or coupling of the spontaneous curvature of the membrane to the local lipid composition. Our results provide evidence that coat proteins are not necessary for budding and fission of vesicles. The physics of the lipid bilayer is rich enough to explain the observed behavior. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 PMID:8274633

Dobereiner, H G; Kas, J; Noppl, D; Sprenger, I; Sackmann, E

1993-01-01

114

Functional genomics of seed dormancy in wheat: advances and prospects.  

PubMed

Seed dormancy is a mechanism underlying the inability of viable seeds to germinate under optimal environmental conditions. To achieve rapid and uniform germination, wheat and other cereal crops have been selected against dormancy. As a result, most of the modern commercial cultivars have low level of seed dormancy and are susceptible to preharvest sprouting when wet and moist conditions occur prior to harvest. As it causes substantial loss in grain yield and quality, preharvest sprouting is an ever-present major constraint to the production of wheat. The significance of the problem emphasizes the need to incorporate an intermediate level of dormancy into elite wheat cultivars, and this requires detailed dissection of the mechanisms underlying the regulation of seed dormancy and preharvest sprouting. Seed dormancy research in wheat often involves after-ripening, a period of dry storage during which seeds lose dormancy, or comparative analysis of seeds derived from dormant and non-dormant cultivars. The increasing development in wheat genomic resources along with the application of transcriptomics, proteomics, and metabolomics approaches in studying wheat seed dormancy have extended our knowledge of the mechanisms acting at transcriptional and post-transcriptional levels. Recent progresses indicate that some of the molecular mechanisms are associated with hormonal pathways, epigenetic regulations, targeted oxidative modifications of seed mRNAs and proteins, redox regulation of seed protein thiols, and modulation of translational activities. Given that preharvest sprouting is closely associated with seed dormancy, these findings will significantly contribute to the designing of efficient strategies for breeding preharvest sprouting tolerant wheat. PMID:25309557

Gao, Feng; Ayele, Belay T

2014-01-01

115

Stratification requirements for seed dormancy alleviation in a wetland weed.  

PubMed

Echinochloaoryzicola(syn.E. phyllopogon) is an exotic weed of California rice paddies that has evolved resistance to multiple herbicides. Elimination of seedlingsthroughcertain weed control methods can limit the spread of this weed, but is contingent on accurate predictions of germination and emergence timing, which are influenced by seed dormancy levels.In summer annuals, dormancy can often be relieved through stratification, a period of prolonged exposure to cold and moist conditions.We used population-based threshold models to quantify the effects of stratification on seed germination of four E. Oryzicola populations at a range of water potential (?) and oxygen levels. We also determined how stratification temperatures, moisture levels and durations contributed to dormancy release. Stratification released dormancy by decreasing base ? and hydrotimerequired for germination and by eliminating any germination sensitivity to oxygen. Stratification also increased average germination rates (GR), which were used as a proxy for relative dormancy levels. Alternating temperatures nearly doubled GR in all populations, indicating that seeds could be partially dormant despite achieving high final germination percentages. Stratification at ??=?0 MPa increased GR compared to stratification at lower water potentials, demonstrating that ? contributed to regulating dormancy release. Maximum GR occurred after 2-4 weeks of stratification at 0 MPa; GR were often more rapid for herbicide-resistant than for herbicide-susceptible seeds, implying greater dormancy in the latter. Manipulation of field conditions to promote dormancy alleviation of E. oryzicola seeds might improve the rate and uniformity of germination for seed bank depletion through seedling weed control. Our results suggest field soil saturation in winter would contribute towards E. oryzicola dormancy release and decrease the time to seedling emergence. PMID:24039714

Boddy, Louis G; Bradford, Kent J; Fischer, Albert J

2013-01-01

116

Functional genomics of seed dormancy in wheat: advances and prospects  

PubMed Central

Seed dormancy is a mechanism underlying the inability of viable seeds to germinate under optimal environmental conditions. To achieve rapid and uniform germination, wheat and other cereal crops have been selected against dormancy. As a result, most of the modern commercial cultivars have low level of seed dormancy and are susceptible to preharvest sprouting when wet and moist conditions occur prior to harvest. As it causes substantial loss in grain yield and quality, preharvest sprouting is an ever-present major constraint to the production of wheat. The significance of the problem emphasizes the need to incorporate an intermediate level of dormancy into elite wheat cultivars, and this requires detailed dissection of the mechanisms underlying the regulation of seed dormancy and preharvest sprouting. Seed dormancy research in wheat often involves after-ripening, a period of dry storage during which seeds lose dormancy, or comparative analysis of seeds derived from dormant and non-dormant cultivars. The increasing development in wheat genomic resources along with the application of transcriptomics, proteomics, and metabolomics approaches in studying wheat seed dormancy have extended our knowledge of the mechanisms acting at transcriptional and post-transcriptional levels. Recent progresses indicate that some of the molecular mechanisms are associated with hormonal pathways, epigenetic regulations, targeted oxidative modifications of seed mRNAs and proteins, redox regulation of seed protein thiols, and modulation of translational activities. Given that preharvest sprouting is closely associated with seed dormancy, these findings will significantly contribute to the designing of efficient strategies for breeding preharvest sprouting tolerant wheat. PMID:25309557

Gao, Feng; Ayele, Belay T.

2014-01-01

117

Wheat seed proteins regulated by imbibition independent of dormancy status.  

PubMed

Seed dormancy is an important trait in wheat (Trticum aestivum L.) and it can be released by germination-stimulating treatments such as after-ripening. Previously, we identified proteins specifically associated with after-ripening mediated developmental switches of wheat seeds from the state of dormancy to germination. Here, we report seed proteins that exhibited imbibition induced co-regulation in both dormant and after-ripened seeds of wheat, suggesting that the expression of these specific proteins/protein isoforms is not associated with the maintenance or release of seed dormancy in wheat. PMID:24084602

Park, Seokhoon; Rampitsch, Christof; Humphreys, Gavin D; Ayele, Belay T

2013-01-01

118

46 CFR 310.6 - Entrance requirements.  

Code of Federal Regulations, 2010 CFR

...Regional Maritime Academies and Colleges § 310.6 Entrance requirements...Possess a secondary school education or equivalent, satisfactory...admission as an undergraduate, to colleges or universities under control of the State...

2010-10-01

119

Wil Wheaton and the Grand Entrance  

NASA Video Gallery

As NASA prepares for Curiosity rover landing on Mars, Wil Wheaton shares this thrilling story of NASA's hardest planetary science mission to date. The video titled, "Grand Entrance," guides viewers...

120

William Shatner and the Grand Entrance  

NASA Video Gallery

As NASA prepares for Curiosity rover landing on Mars, William Shatner shares this thrilling story of NASA's hardest planetary science mission to date. The video titled, "Grand Entrance," guides vie...

121

The perivascular niche regulates breast tumour dormancy.  

PubMed

In a significant fraction of breast cancer patients, distant metastases emerge after years or even decades of latency. How disseminated tumour cells (DTCs) are kept dormant, and what wakes them up, are fundamental problems in tumour biology. To address these questions, we used metastasis assays in mice and showed that dormant DTCs reside on microvasculature of lung, bone marrow and brain. We then engineered organotypic microvascular niches to determine whether endothelial cells directly influence breast cancer cell (BCC) growth. These models demonstrated that endothelial-derived thrombospondin-1 induces sustained BCC quiescence. This suppressive cue was lost in sprouting neovasculature; time-lapse analysis showed that sprouting vessels not only permit, but accelerate BCC outgrowth. We confirmed this surprising result in dormancy models and in zebrafish, and identified active TGF-?1 and periostin as tumour-promoting factors derived from endothelial tip cells. Our work reveals that stable microvasculature constitutes a dormant niche, whereas sprouting neovasculature sparks micrometastatic outgrowth. PMID:23728425

Ghajar, Cyrus M; Peinado, Héctor; Mori, Hidetoshi; Matei, Irina R; Evason, Kimberley J; Brazier, Hélène; Almeida, Dena; Koller, Antonius; Hajjar, Katherine A; Stainier, Didier Y R; Chen, Emily I; Lyden, David; Bissell, Mina J

2013-07-01

122

The perivascular niche regulates breast tumor dormancy  

PubMed Central

In a significant fraction of breast cancer patients, distant metastases emerge after years or even decades of latency. How disseminated tumor cells (DTCs) are kept dormant, and what ‘wakes them up’, are fundamental problems in tumor biology. To address these questions, we utilized metastasis assays in mice to show that dormant DTCs reside upon microvasculature of lung, bone marrow and brain. We then engineered organotypic microvascular niches to determine whether endothelial cells directly influence breast cancer cell (BCC) growth. These models demonstrated that endothelial-derived thrombospondin-1 induces sustained BCC quiescence. This suppressive cue was lost in sprouting neovasculature; time-lapse analysis showed that sprouting vessels not only permit, but accelerate BCC outgrowth. We confirmed this surprising result in dormancy models and in zebrafish, and identified active TGF-?1 and periostin as tumor-promoting, endothelial tip cell-derived factors. Our work reveals that stable microvasculature constitutes a ‘dormant niche,’ whereas sprouting neovasculature sparks micrometastatic outgrowth. PMID:23728425

Peinado, Hector; Mori, Hidetoshi; Matei, Irina R.; Evason, Kimberley J.; Brazier, Helene; Almeida, Dena; Koller, Antonius; Hajjar, Katherine A.; Stainier, Didier Y.R.; Chen, Emily I.; Lyden, David

2013-01-01

123

Oxidative signaling in seed germination and dormancy  

PubMed Central

Reactive Oxygen Species (ROS) play a key role in various events of seed life. In orthodox seeds, ROS are produced from embryogenesis to germination, i.e., in metabolically active cells, but also in quiescent dry tissues during after ripening and storage, owing various mechanisms depending on the seed moisture content. Although ROS have been up to now widely considered as detrimental to seeds, recent advances in plant physiology signaling pathways has lead to reconsider their role. ROS accumulation can therefore be also beneficial for seed germination and seedling growth by regulating cellular growth, ensuring a protection against pathogens or controlling the cell redox status. ROS probably also act as a positive signal in seed dormancy release. They interact with abscisic acid and gibberellins transduction pathway and are likely to control numerous transcription factors and properties of specific protein through their carbonylation. PMID:19513212

El-Maarouf-Bouteau, Hayat

2008-01-01

124

Influence of flower bud density, flower bud drop and fruit set on apricot productivity  

Microsoft Academic Search

Flower bud density, flower bud drop and fruit set were studied for nine apricot cultivars in order to understand the influence of these variables on apricot biology and productivity. Cultivars in southern Spain were chosen as representatives of different flowering times and productivity. Results indicate differences among cultivars in the studied parameters. Low flower bud production, high flower bud drop

N. Alburquerque; L. Burgos; J. Egea

2004-01-01

125

Eyeing emergence: modified treatments for terminating dormancy of conifer seeds.  

PubMed

Many seeds of coniferous species display a deep primary dormancy at maturity and require several weeks of pretreatment to produce seed populations that germinate in a vigorous and timely manner. Facilitating an efficient transition from dormancy to germination by devising improved protocols for dormancy breakage is not only important to conifer seed research, aiding in the study of the dormancy process itself, but is also of interest and applicability to commercial forest nursery operations. In the forests of British Columbia, Canada, several conifer species are well-adapted to their environment, with seeds needing to experience long durations in the moist state at cool or fluctuating temperatures. These include yellow-cedar (Callitropsis nootkatensis), western white pine (Pinus monticola), and true fir species, such as Pacific silver fir and subalpine fir (Abies amabilis and A. lasiocarpa, respectively). In this chapter, we discuss the development of new dormancy-breaking protocols for the aforementioned species that centre on the balance of several key aspects: (1) reducing the time needed to terminate dormancy in the seed population; (2) synchronicity of germination; (3) ease of use; (4) cost-effectiveness; and (5) repeatability. Where possible, any new or modified protocol should be further tested in relationship to promoting rapid seedling growth in a forest nursery greenhouse setting and after planting at natural stands. Based on the five criteria listed above, very significant improvements compared to traditional dormancy-breaking methods have been achieved for the targeted conifer species. Where tested (e.g. yellow-cedar), the modified dormancy-breaking treatments result in vigorous growth in the greenhouse and after planting at natural stands. PMID:21898249

Feurtado, J Allan; Kermode, Allison R

2011-01-01

126

Metabolic Dormancy and Responses to Environmental Desiccation in Fish Embryos  

Microsoft Academic Search

\\u000a Metabolic depression is relatively uncommon among the fishes with the greatest number of species exhibiting dormancy as embryos.\\u000a Dormancy in fish embryos is largely associated with deposition of embryos into terrestrial habitats to avoid embryo predation\\u000a or to survive intermittent drying of aquatic habitats. Killifish embryos in general, and especially the embryos of annual\\u000a killifish, are highly adapted for life

Jason E. Podrabsky; Angèle Tingaud-Sequeira; Joan Cerdà

127

Using Generic Data to Establish Dormancy Failure Rates  

NASA Technical Reports Server (NTRS)

Many hardware items are dormant prior to being operated. The dormant period might be especially long, for example during missions to the moon or Mars. In missions with long dormant periods the risk incurred during dormancy can exceed the active risk contribution. Probabilistic Risk Assessments (PRAs) need to account for the dormant risk contribution as well as the active contribution. A typical method for calculating a dormant failure rate is to multiply the active failure rate by a constant, the dormancy factor. For example, some practitioners use a heuristic and divide the active failure rate by 30 to obtain an estimate of the dormant failure rate. To obtain a more empirical estimate of the dormancy factor, this paper uses the recently updated database NPRD-2011 [1] to arrive at a set of distributions for the dormancy factor. The resulting dormancy factor distributions are significantly different depending on whether the item is electrical, mechanical, or electro-mechanical. Additionally, this paper will show that using a heuristic constant fails to capture the uncertainty of the possible dormancy factors.

Reistle, Bruce

2014-01-01

128

Effects of Dormancy Regulating Chemicals on Innate and Salinity Induced Dormancy in the Invasive Prosopis juliflora (Sw.) DC. Shrub  

Microsoft Academic Search

The effect of different types and concentrations of dormancy regulating chemicals (DRCs) on innate and induced dormancy was evaluated under optimal germination conditions in the invasive Prosopis juliflora shrub. Lower concentrations of gibberellic acid (0.3 mM) and kinetin (0.05 mM) were more effective in enhancing germination % and rate at higher concentrations of NaCl, but the reverse was true for thiourea. None

Ali-El-Keblawy; Fatima Al-Ansari; Awatif Al-Rawai

2005-01-01

129

The role of metastasis suppressor genes in metastatic dormancy  

PubMed Central

Metastasis suppressor genes (MSGs) are defined by their ability to inhibit overt metastasis in a secondary organ without affecting tumor growth at the primary site. Over 20 MSGs have been confirmed in vivo. This class of genes is only unified by their capacity to suppress metastasis, as they encode for proteins with a wide range of biochemical activities that are components of a variety of signaling pathways. In addition, metastasis suppressors impinge upon different stages of the metastatic cascade to manifest their suppressive effects. The MSGs KISS1, KAI1, MKK4/7 and Nm23-H1 promote tumor dormancy at the metastatic site, since tumor cells with induced expression of these MSGs disseminate, but do not form overt metastases in the secondary organ throughout the duration of a metastasis assay. Evidence suggests that KISS1 triggers dormancy in solitary, metastatic tumor cells by causing growth arrest of solitary cells at the secondary site. KAI1 induces growth arrest prior to extravasation by binding a vascular endothelial cell surface marker. MKK4, MKK7 and Nm23-H1 appear to promote dormancy of micrometastatic colonies, after disseminated tumor cells have undergone several rounds of proliferation. Other MSGs may also function in tumor dormancy, but so far their role has not been fully elucidated. Therapeutic approaches that either mimic the effects of MSGs or re-establish MSG expression in metastatic lesions may hold promise for the establishment or maintenance of dormancy. PMID:18834404

HORAK, CHRISTINE E.; LEE, JONG HEUN; MARSHALL, JEAN-CLAUDE; SHREEVE, S. MARTIN; STEEG, PATRICIA S.

2012-01-01

130

Hydrothermal time analysis of seed dormancy in true (botanical) potato seeds  

Microsoft Academic Search

As seed dormancy is released within a seed population, both the rate and percentage of germina- tion increase progressively with increasing dose of a dormancy-breaking treatment or condition. Popu- lation-based models can account for this behaviour on the basis of shifting response thresholds as dormancy is alleviated. In particular, hydrothermal time analysis of germination sensitivity to water potential (C) and

Kent J. Bradford; Veria Alvarado

2005-01-01

131

University Entrance Examinations in Brazil: Measurement Procedures.  

ERIC Educational Resources Information Center

New legislation on education, introduced in Brazil from 1968 to 1971, addresses university entrance requirements and exam characteristics by calling for centralization of exam preparation, examinee registration, test administration, test scoring and result reporting, and the use of objective tests. The Brazilian educational structure has three…

Bessa, Nicia M.

132

Supercalculators and University Entrance Calculus Examinations.  

ERIC Educational Resources Information Center

Investigates whether the use of computer algebra systems could provide a significant advantage to students taking standard university entrance calculus examinations. Indicates that supercalculators would probably provide a significant advantage, particularly for lower-achieving students. Demonstrates that it is possible to write questions in which…

Hong, Ye Yoon; Thomas, Mike; Kiernan, Christine

2000-01-01

133

EARLY-AGE ENTRANCE TO FIRST GRADE.  

ERIC Educational Resources Information Center

THREE AREAS WERE CONSIDERED IN "EARLY-AGE ENTRANCE TO FIRST GRADE." FIRST, A LIST OF BACKGROUND MATERIALS USED INCLUDED SENATE NUMBER 723, DELORES DURKIN'S "CHILDREN WHO LEARNED TO READ AT HOME," AND "AN EARLIER START IN READING," JAMES R. HOBSON'S "HIGH SCHOOL PERFORMANCE OF UNDERAGE PUPILS INITIALLY ADMITTED TO KINDERGARTEN ON THE BASIS OF…

BONSALL, MARCELLA; AND OTHERS

134

The University Entrance Examination System in China  

ERIC Educational Resources Information Center

Every year, millions of high school students sit the Chinese national university entrance exam, and their results determine entry into universities or alternatives such as employment. Limited information about the exam is available in the Western literature even though it determines the future of millions of young people, and is increasingly of…

Davey, Gareth; De Lian, Chuan; Higgins, Louise

2007-01-01

135

Cancer dormancy: isolation and characterization of dormant lymphoma cells.  

PubMed Central

"Tumor dormancy" is an operational term used to describe a prolonged quiescent state in which tumor cells are present, but tumor progression is not clinically apparent. Although clinical examples of tumor dormancy abound, little is known regarding the mechanisms underlying this state. Here we utilize an antibody-induced dormancy model of an aggressive murine B-cell lymphoma (BCL1) and show that the induction of the dormant state is accompanied by dramatic changes in tumor cell morphology and cell cycle status. These data indicate the feasibility of altering the malignant phenotype of transformed cells by specific signals originating at the cell surface, and they suggest new opportunities for therapeutic intervention in cancer. Images Fig. 1 Fig. 2 Fig. 3 PMID:8446596

Yefenof, E; Picker, L J; Scheuermann, R H; Tucker, T F; Vitetta, E S; Uhr, J W

1993-01-01

136

Laminar flow control via utilization of pipe entrance inserts (a comment on entrance length concept)  

Microsoft Academic Search

Flow field measurements behind pipe entrance inserts called as flow conditioners in a mean flow Reynolds number range 547?Re?9000 are presented herein. A tube bundle, a Laws’ perforated plate and an etoile were located at the entrance of a smooth circular pipe of inner diameter, D=26.6mm. The covered ranges of open area ratio, ? and non-dimensional length, L\\/D were 0.49???0.74

Melda Özdinç Çarp?nl?o?lu; Emrah Özahi

2011-01-01

137

Repellence of the red bud borer (Resseliella oculiperda) to grafted apple trees by impregnation of budding tape with essential oils  

Microsoft Academic Search

The red bud borer Resseliella oculiperda (Rübs.) is a pest insect of apple trees when rootstocks are grafted with scion buds by shield budding. The female midges are attracted to the wounds of the grafted buds where they lay their eggs. The larvae feed on the cambium and destroy the buds completely or partially, leading to bad union of the

Tol van R. W. H. M; Linden van der A; H. J. Swarts; J. H. Visser

2007-01-01

138

DELLA-mediated cotyledon expansion breaks coat-imposed seed dormancy.  

PubMed

Seed dormancy is a key adaptive trait in plants responsible for the soil seed bank. The long established hormone-balance theory describes the antagonistic roles of the dormancy promoting plant hormone abscisic acid (ABA), and the germination promoting hormone gibberellin (GA) in dormancy control. Light, temperature, and other dormancy-breaking signals function to modulate the synthesis and perception of these hormones in the seed. However, the way in which these hormones control dormancy in the imbibed seed remains unknown. Here, we show that the DELLA protein regulators of the GA response are required for dormancy and describe a model through which hormone signal integration and dormancy regulation is achieved. We demonstrate that cotyledon expansion precedes radicle emergence during Arabidopsis seed germination and that a striking correlation exists between final seedling cotyledon size and seed dormancy in the DELLA mutants. Furthermore, twelve previously characterized seed-dormancy mutants are also defective in the control of cotyledon size in a manner consistent with their effect on germination potential. We propose that DELLA-mediated, light-, temperature-, and hormone-responsive cotyledon expansion prior to radicle emergence overcomes dormancy imposed by the seed coat and underlies seed-dormancy control in Arabidopsis. PMID:17141619

Penfield, Steven; Gilday, Alison D; Halliday, Karen J; Graham, Ian A

2006-12-01

139

57. POWDER MAGAZINE, DETAIL VIEW OF NORTHEAST FRONT ENTRANCE TO ...  

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

57. POWDER MAGAZINE, DETAIL VIEW OF NORTHEAST FRONT ENTRANCE TO ACESS PASSAGE TO MAGAZINES FROM INTERIOR OF MAGAZINE SHOWING VENTILATION WINDOWS (BARRED) FLANKING ENTRANCE DOOR (OPEN). NOTE ACCESS PASSAGE TO ADJOING MAGAZINE. - Fort Monroe, Fortress, Hampton, Hampton, VA

140

6. DETAIL VIEW OF ENTRANCE GATES, SHOWING IRON GATE, STONE ...  

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

6. DETAIL VIEW OF ENTRANCE GATES, SHOWING IRON GATE, STONE WORK, AND GATE STOP FROM SOUTHEAST OF NORTHWEST ELEMENTS. - William Enston Home, Entrance Gate, 900 King Street, Charleston, Charleston County, SC

141

Clinal Variation in phyB2, a Candidate Gene for Day-Length-Induced Growth Cessation and Bud Set, Across a Latitudinal Gradient in European Aspen (Populus tremula)  

PubMed Central

The initiation of growth cessation and dormancy represents a critical ecological and evolutionary trade-off between survival and growth in most forest trees. The most important environmental cue regulating the initiation of dormancy is a shortening of the photoperiod and phytochrome genes have been implicated in short-day-induced bud set and growth cessation in Populus. We characterized patterns of DNA sequence variation at the putative candidate gene phyB2 in 4 populations of European aspen (Populus tremula) and scored single-nucleotide polymorphisms in an additional 12 populations collected along a latitudinal gradient in Sweden. We also measured bud set from a subset of these trees in a growth chamber experiment. Buds set showed significant clinal variation with latitude, explaining ?90% of the population variation in bud set. A sliding-window scan of phyB2 identified six putative regions with enhanced population differentiation and four SNPs showed significant clinal variation. The clinal variation at individual SNPs is suggestive of an adaptive response in phyB2 to local photoperiodic conditions. Three of four SNPs showing clinal variation were located in regions with excessive genetic differentiation, demonstrating that searching for regions of high genetic differentiation can be useful for identifying sites putatively involved in local adaptation. PMID:16361240

Ingvarsson, Par K.; Garcia, M. Victoria; Hall, David; Luquez, Virginia; Jansson, Stefan

2006-01-01

142

Entrance channel cluster folding potentials for knockout reactions  

SciTech Connect

The entrance channel optical potentials for ({alpha},2{alpha}) reactions are calculated using single folding models. These are found to be much different from the conventional entrance channel potentials and use of these folded entrance channel optical potentials significantly change the absolute cross sections. Small reductions in the entrance channel potentials are found to increase the peak to dip cross section ratios drastically for the knockout of {alpha}-clusters bound in the l=1 state.

Jain, Arun K.; Joshi, B. N. [Nuclear Physics Division, Bhabha Atomic Research Center, Mumbai-400 085 (India)

2008-02-15

143

ESSAY REVIEW The evolutionary ecology of vegetative dormancy in  

E-print Network

Richard P. Shefferson* Odum School of Ecology, University of Georgia, Athens, GA 30602, USA Summary 1. I is more complex, because some species increase flowering and fruiting after dormancy while others do: (i) photosynthesis and (ii) the opportunity to flower and reproduce. The costs include: (i) greater

Shefferson, Richard P.

144

Primary and Secondary Dormancy in Lomatium Dissectum Seeds  

Microsoft Academic Search

Lomatium Dissectum (Apiaceae) is a perennial, herbaceous plant of wide distribution in Western North America. At the time of dispersal, L. dissectum seeds are dormant and have underdeveloped embryos. We investigated the environmental requirements for dormancy break and embryo growth. The embryos elongated between five and seven fold inside the seeds over several weeks of cold stratification. Embryo growth prior

Jacklyn Donahue; Michelle Perez

2009-01-01

145

Role of kinetin in the dormancy of Cercis siliquastrum seeds  

Microsoft Academic Search

Summary Studies conducted onCercis siliquastrum seeds treated with kinetin confirm that this hormone does not interrupt dormancy in either whole seeds or those decoated at the radical pole. Seeds totally decoated or decoated at the cotyledon pole only demonstrated atypical germinations linked to cotyledon growth, permitting the embryo to escape the inhibitory action present in the endosperm; this does not

Paola Gastaldo; Paola Profumo; Liliana Caffaro Corti

1982-01-01

146

Metastasis Dormancy in Estrogen Receptor-Positive Breast Cancer  

PubMed Central

About 20-40% of breast cancer patients eventually develop recurrences in distant organs, which are often not detected until years to decades after the primary tumor diagnosis. This phenomenon is especially pronounced in ER+ breast cancer, suggesting that ER+ cancer cells may stay dormant for a protracted period of time, despite adjuvant therapies. Multiple mechanisms have been proposed to explain how cancer cells survive and remain in dormancy , and how they become reactivated and exit dormancy. These mechanisms include angiogenic switch, immunosurveillance, and interaction with extracellular matrix (ECM) and stromal cells. How to eradicate or suppress these dormant cancer cells remains a major clinical issue because of the lack of knowledge about the biological and clinical nature of these cells. Herein, we review the clinical manifestation of metastasis dormancy in ER+ tumors, the current biological insights of tumor dormancy obtained from various experimental models, and the clinical challenges to predict, detect, and treat dormant metastases. We also discuss future research directions toward a better understanding of the biological mechanisms and clinical management of ER+ dormant metastasis. PMID:24298069

Zhang, Xiang H.-F.; Giuliano, Mario; Trivedi, Meghana V.; Schiff, Rachel; Kent Osborne, C.

2013-01-01

147

Ethylene, a key factor in the regulation of seed dormancy  

PubMed Central

Ethylene is an important component of the gaseous environment, and regulates numerous plant developmental processes including seed germination and seedling establishment. Dormancy, the inability to germinate in apparently favorable conditions, has been demonstrated to be regulated by the hormonal balance between abscisic acid (ABA) and gibberellins (GAs). Ethylene plays a key role in dormancy release in numerous species, the effective concentrations allowing the germination of dormant seeds ranging between 0.1 and 200 ?L L-1. Studies using inhibitors of ethylene biosynthesis or of ethylene action and analysis of mutant lines altered in genes involved in the ethylene signaling pathway (etr1, ein2, ain1, etr1, and erf1) demonstrate the involvement of ethylene in the regulation of germination and dormancy. Ethylene counteracts ABA effects through a regulation of ABA metabolism and signaling pathways. Moreover, ethylene insensitive mutants in Arabidopsis are more sensitive to ABA and the seeds are more dormant. Numerous data also show an interaction between ABA, GAs and ethylene metabolism and signaling pathways. It has been increasingly demonstrated that reactive oxygen species (ROS) may play a significant role in the regulation of seed germination interacting with hormonal signaling pathways. In the present review the responsiveness of seeds to ethylene will be described, and the key role of ethylene in the regulation of seed dormancy via a crosstalk between hormones and other signals will be discussed.

Corbineau, Francoise; Xia, Qiong; Bailly, Christophe

2014-01-01

148

Dormancy-associated MADS genes from the EVG locus of peach [Prunus persica (L.) Batsch] have distinct seasonal and photoperiodic expression patterns  

PubMed Central

Mapping and sequencing of the non-dormant evg mutant in peach [Prunus persica (L.) Batsch] identified six tandem-arrayed DAM (dormancy-associated MADS-box) genes as candidates for regulating growth cessation and terminal bud formation. To narrow the list of candidate genes, an attempt was made to associate bud phenology with the seasonal and environmental patterns of expression of the candidates in wild-type trees. The expression of the six peach DAM genes at the EVG locus of peach was characterized throughout an annual growing cycle in the field, and under controlled conditions in response to a long day–short day photoperiod transition. DAM1, 2, 4, 5, and 6 were responsive to a reduction in photoperiod in controlled conditions and the direction of response correlated with the seasonal timing of expression in field-grown trees. DAM3 did not respond to photoperiod and may be regulated by chilling temperatures. The DAM genes in peach appear to have at least four distinct patterns of expression. DAM1, 2, and 4 are temporally associated with seasonal elongation cessation and bud formation and are the most likely candidates for control of the evg phenotype. PMID:19553369

Li, Zhigang; Reighard, Gregory Lynn; Abbott, Albert Glenn; Bielenberg, Douglas Gary

2009-01-01

149

Mitochondrial network size scaling in budding yeast.  

PubMed

Mitochondria must grow with the growing cell to ensure proper cellular physiology and inheritance upon division. We measured the physical size of mitochondrial networks in budding yeast and found that mitochondrial network size increased with increasing cell size and that this scaling relation occurred primarily in the bud. The mitochondria-to-cell size ratio continually decreased in aging mothers over successive generations. However, regardless of the mother's age or mitochondrial content, all buds attained the same average ratio. Thus, yeast populations achieve a stable scaling relation between mitochondrial content and cell size despite asymmetry in inheritance. PMID:23139336

Rafelski, Susanne M; Viana, Matheus P; Zhang, Yi; Chan, Yee-Hung M; Thorn, Kurt S; Yam, Phoebe; Fung, Jennifer C; Li, Hao; Costa, Luciano da F; Marshall, Wallace F

2012-11-01

150

Mitochondrial Network Size Scaling in Budding Yeast**  

PubMed Central

Mitochondria must grow with the growing cell to ensure proper cellular physiology and inheritance upon division. We measured the physical size of mitochondrial networks in budding yeast and found that mitochondrial network size increased with increasing cell size and that this scaling relation occurred primarily in the bud. The mitochondria to cell size ratio continually decreased in aging mothers over successive generations. However, regardless of mother age or mitochondrial content, all buds attained the same average ratio. Thus, yeast populations achieve a stable scaling relation between mitochondrial content and cell size despite asymmetry in inheritance. PMID:23139336

Rafelski, Susanne M.; Viana, Matheus P.; Zhang, Yi; Chan, Yee-Hung M.; Thorn, Kurt S.; Yam, Phoebe; Fung, Jennifer C.; Li, Hao; Costa, Luciano da F.; Marshall, Wallace F.

2013-01-01

151

Phylogeny of seed dormancy in Convolvulaceae, subfamily Convolvuloideae (Solanales)  

PubMed Central

Background and Aims The water gap is an important morphoanatomical structure in seeds with physical dormancy (PY). It is an environmental signal detector for dormancy break and the route of water into the non-dormant seed. The Convolvulaceae, which consists of subfamilies Convolvuloideae (11 tribes) and Humbertoideae (one tribe, monotypic Humberteae), is the only family in the asterid clade known to produce seeds with PY. The primary aim of this study was to compare the morphoanatomical characteristics of the water gap in seeds of species in the 11 tribes of the Convolvuloideae and to use this information, and that on seed dormancy and storage behaviour, to construct a phylogenetic tree of seed dormancy for the subfamily. Methods Scanning electron microscopy (SEM) was used to define morphological changes in the hilum area during dormancy break; hand and vibratome sections were taken to describe the anatomy of the water gap, hilum and seed coat; and dye tracking was used to identify the initial route of water entry into the non-dormant seed. Results were compared with a recent cladogram of the family. Key Results Species in nine tribes have (a) layer(s) of palisade cells in the seed coat, a water gap and orthodox storage behaviour. Erycibe (Erycibeae) and Maripa (Maripeae) do not have a palisade layer in the seed coat or a water gap, and are recalcitrant. The hilar fissure is the water gap in relatively basal Cuscuteae, and bulges adjacent to the micropyle serve as the water gap in the Convolvuloideae, Dicranostyloideae (except Maripeae) and the Cardiochlamyeae clades. Seeds from the Convolvuloideae have morphologically prominent bulges demarcated by cell shape in the sclereid layer, whereas the Dicranostyloideae and Cardiochlamyeae have non-prominent bulges demarcated by the number of sub-cell layers. The anatomy and morphology of the hilar pad follow the same pattern. Conclusions PY in the subfamily Convolvuloideae probably evolved in the aseasonal tropics from an ancestor with recalcitrant non-dormant seeds, and it may have arisen as Convolvulaceae radiated to occupy the seasonal tropics. Combinational dormancy may have developed in seeds of some Cuscuta spp. as this genus moved into temperate habitats. PMID:19074450

Jayasuriya, K. M. G. Gehan; Baskin, Jerry M.; Geneve, Robert L.; Baskin, Carol C.

2009-01-01

152

Tumor dormancy: potential therapeutic target in tumor recurrence and metastasis prevention  

PubMed Central

In past decades, cancer patient survival has been improved with earlier detection and advancements in therapy. However, many patients who exhibit no clinical symptoms after frontline therapy subsequently suffer, often many years later, aggressive tumor recurrence. Cancer recurrence represents a critical clinical challenge in effectively treating malignancies and for patients’ quality of life. Tumor cell dormancy may help to explain treatment resistance and recurrence or metastatic reactivation. Understanding the dormant stage of tumor cells may help in discovering ways to maintain the dormant state or permanently eliminate dormant residual disseminated tumor cells. Over the past decade, numerous studies indicate that various mechanisms of tumor dormancy exist, including cellular dormancy (quiescence), angiogenic dormancy, and immunologic dormancy. In this short review, we summarize recent experimental and clinical evidence for these three mechanisms and other possible tumor microenvironment mechanisms that may influence tumor dormancy. PMID:24502434

2013-01-01

153

A Cellular Automaton Model for Tumor Dormancy: Emergence of a Proliferative Switch  

E-print Network

Malignant cancers that lead to fatal outcomes for patients may remain dormant for very long periods of time. Although individual mechanisms such as cellular dormancy, angiogenic dormancy and immunosurveillance have been proposed, a comprehensive understanding of cancer dormancy and the "switch" from a dormant to a proliferative state still needs to be strengthened from both a basic and clinical point of view. Computational modeling enables one to explore a variety of scenarios for possible but realistic microscopic dormancy mechanisms and their predicted outcomes. The aim of this paper is to devise such a predictive computational model of dormancy with an emergent "switch" behavior. Specifically, we generalize a previous cellular automaton (CA) model for proliferative growth of solid tumor that now incorporates a variety of cell-level tumor-host interactions and different mechanisms for tumor dormancy, for example the effects of the immune system. Our new CA rules induce a natural "competition" between the tu...

Chen, Duyu; Torquato, Salvatore

2014-01-01

154

A local dormancy cline is related to the seed maturation environment, population genetic composition and climate  

PubMed Central

Background and Aims Seed dormancy varies within species in response to climate, both in the long term (through ecotypes or clines) and in the short term (through the influence of the seed maturation environment). Disentangling both processes is crucial to understand plant adaptation to environmental changes. In this study, the local patterns of seed dormancy were investigated in a narrow endemic species, Centaurium somedanum, in order to determine the influence of the seed maturation environment, population genetic composition and climate. Methods Laboratory germination experiments were performed to measure dormancy in (1) seeds collected from different wild populations along a local altitudinal gradient and (2) seeds of a subsequent generation produced in a common garden. The genetic composition of the original populations was characterized using intersimple sequence repeat (ISSR) PCR and principal co-ordinate analysis (PCoA), and its correlation with the dormancy patterns of both generations was analysed. The effect of the local climate on dormancy was also modelled. Key Results An altitudinal dormancy cline was found in the wild populations, which was maintained by the plants grown in the common garden. However, seeds from the common garden responded better to stratification, and their release from dormancy was more intense. The patterns of dormancy variation were correlated with genetic composition, whereas lower temperature and summer precipitation at the population sites predicted higher dormancy in the seeds of both generations. Conclusions The dormancy cline in C. somedanum is related to a local climatic gradient and also corresponds to genetic differentiation among populations. This cline is further affected by the weather conditions during seed maturation, which influence the receptiveness to dormancy-breaking factors. These results show that dormancy is influenced by both long-and short-term climatic variation. Such processes at such a reduced spatial scale highlight the potential of plants to adapt to fast environmental changes. PMID:23864001

Fernandez-Pascual, Eduardo; Jimenez-Alfaro, Borja; Caujape-Castells, Juli; Jaen-Molina, Ruth; Diaz, Tomas Emilio

2013-01-01

155

Habitat preferences as related to the prolonged dormancy of perennial herbs and ferns  

Microsoft Academic Search

Prolonged dormancy (hereafter dormancy), a phenomenon in which a perennial herbaceous plant does not sprout for one or more\\u000a years, is examined. The phenomenon may be more frequent than stated so far and discovery of its role in plant life history\\u000a and performance is still underway. Data from published papers was reviewed and all known species exhibiting dormancy were\\u000a analysed

Margit Reintal; Kadri Tali; Marina Haldna; Tiiu Kull

2010-01-01

156

Variation in dormancy and germination in three co-occurring perennial forest herbs  

Microsoft Academic Search

Mesic deciduous forest herbs often disperse seed with morphophysiological dormancy (MPD) that prevents germination during\\u000a unfavorable periods for seedling survival. However, for seeds of some species with MPD, seasonal separation of root and shoot\\u000a emergence and variation in dormancy levels can complicate interpretation of seedling emergence timing in the field. We tested\\u000a whether dormancy-break and germination requirements differed among co-occurring

Matthew A. Albrecht; Brian C. McCarthy

157

A genetic model and molecular markers for wild oat (Avena fatua L.) seed dormancy  

Microsoft Academic Search

Seed dormancy allows weed seeds to persist in agricultural soils. Wild oat (Avena fatua L.) is a major weed of cereal grains and expresses a range of seed dormancy phenotypes. Genetic analysis of wild oat dormancy\\u000a has been complicated by the difficulty of phenotypic classification in segregating populations. Therefore, little is known\\u000a about the nature of the genes that regulate

S. A. Fennimore; W. E. Nyquist; G. E. Shaner; R. W. Doerge; M. E. Foley

1999-01-01

158

Mechanisms of disseminated cancer cell dormancy: an awakening field  

PubMed Central

Metastases arise from residual disseminated tumour cells (DTCs). This can happen years after primary tumour treatment because residual tumour cells can enter dormancy and evade therapies. As the biology of minimal residual disease seems to diverge from that of proliferative lesions, understanding the underpinnings of this new cancer biology is key to prevent metastasis. Analysis of approximately 7 years of literature reveals a growing focus on tumour and normal stem cell quiescence, extracellular and stromal microenvironments, autophagy and epigenetics as mechanisms that dictate tumour cell dormancy. In this Review, we attempt to integrate this information and highlight both the weaknesses and the strengths in the field to provide a framework to understand and target this crucial step in cancer progression. PMID:25118602

Sosa, María Soledad; Bragado, Paloma; Aguirre-Ghiso, Julio A.

2014-01-01

159

Dormancy phases in seeds of Verbascum thapsus L  

Microsoft Academic Search

Summary Seeds ofVerbascum thapsus were imbibed on filter papers in Petri dishes and were exposed to a series of temperatures of 4°C?10°C?20°C?10°C?4°C in darkness. After each temperature treatment lasting one month, samples were removed and tested in light and darkness over a range of alternating temperatures. The results showed us that the dormancy state changes gradually according to the imbibition

Koen A. Vanlerberghe; Jozef A. Van Assche

1986-01-01

160

Human Granuloma In Vitro Model, for TB Dormancy and Resuscitation  

PubMed Central

Tuberculosis (TB) is responsible for death of nearly two million people in the world annually. Upon infection, Mycobacterium tuberculosis (Mtb) causes formation of granuloma where the pathogen goes into dormant state and can live for decades before resuscitation to develop active disease when the immune system of the host is weakened and/or suppressed. In an attempt to better understand host-pathogen interactions, several groups have been developing in vitro models of human tuberculosis granuloma. However, to date, an in vitro granuloma model in which Mtb goes into dormancy and can subsequently resuscitate under conditions that mimic weakening of the immune system has not been reported. We describe the development of a biomimetic in vitro model of human tuberculosis granuloma using human primary leukocytes, in which the Mtb exhibited characteristics of dormant mycobacteria as demonstrated by (1) loss of acid-fastness, (2) accumulation of lipid bodies (3) development of rifampicin-tolerance and (4) gene expression changes. Further, when these micro granulomas were treated with immunosuppressant anti-tumor necrosis factor-alpha monoclonal antibodies (anti-TNF? mAbs), resuscitation of Mtb was observed as has been found in humans. In this human in vitro granuloma model triacylglycerol synthase 1deletion mutant (?tgs1) with impaired ability to accumulate triacylglycerides (TG), but not the complemented mutant, could not go into dormancy. Deletion mutant of lipY, with compromised ability to mobilize the stored TG, but not the complemented mutant, was unable to come out of dormancy upon treatment with anti-TNF? mAbs. In conclusion, we have developed an in vitro human tuberculosis granuloma model that largely exhibits functional features of dormancy and resuscitation observed in human tuberculosis. PMID:23308269

Kapoor, Nidhi; Pawar, Santosh; Sirakova, Tatiana D.; Deb, Chirajyoti; Warren, William L.; Kolattukudy, Pappachan E.

2013-01-01

161

Expression and activity of antioxidant enzymes during potato tuber dormancy  

Microsoft Academic Search

Summary  The expression of antioxidant genes has been analyzed in a potato plant and during tuber dormancy. Manganese superoxide dismutase\\u000a (MnSOD), cytosolic copper and zinc superoide dismutase (Cu\\/ZnSOD), catalase class II, cytosolic ascorbate peroxidase (APX)\\u000a and glutathione peroxidase (GPX) are expressed at the RNA level in all the contexts analyzed. By contrast, the expression\\u000a of the iron superoxide dismutase (FeSOD) and

J. A. Rojas-Beltran; F. Dejaeghere; M. Abd Alla Kotb; P. Du Jardin

2000-01-01

162

Senescence, dormancy and tillering in perennial C4 grasses.  

PubMed

Perennial, temperate, C4 grasses, such as switchgrass and miscanthus have been tabbed as sources of herbaceous biomass for the production of green fuels and chemicals based on a number of positive agronomic traits. Although there is important literature on the management of these species for biomass production on marginal lands, numerous aspects of their biology are as yet unexplored at the molecular level. Perenniality, a key agronomic trait, is a function of plant dormancy and winter survival of the below-ground parts of the plants. These include the crowns, rhizomes and meristems that will produce tillers. Maintaining meristem viability is critical for the continued survival of the plants. Plant tillers emerge from the dormant crown and rhizome meristems at the start of the growing period in the spring, progress through a phase of vegetative growth, followed by flowering and eventually undergo senescence. There is nutrient mobilization from the aerial portions of the plant to the crowns and rhizomes during tiller senescence. Signals arising from the shoots and from the environment can be expected to be integrated as the plants enter into dormancy. Plant senescence and dormancy have been well studied in several dicot species and offer a potential framework to understand these processes in temperate C4 perennial grasses. The availability of latitudinally adapted populations for switchgrass presents an opportunity to dissect molecular mechanisms that can impact senescence, dormancy and winter survival. Given the large increase in genomic and other resources for switchgrass, it is anticipated that projected molecular studies with switchgrass will have a broader impact on related species. PMID:24467906

Sarath, Gautam; Baird, Lisa M; Mitchell, Robert B

2014-03-01

163

A combined physical and physiological dormancy controls seasonal seedling emergence of Geranium robertianum.  

PubMed

Temperate forest herbs with seeds exhibiting both a physical and a physiological dormancy mechanism are rare, and knowledge on the factors regulating germination of these species is fragmentary. The biennial Geranium robertianum L. grows mainly in temperate woodlands, but can also be found in exposed habitats. Seedlings of G. robertianum are known to emerge from spring until autumn, but little is known about the environmental factors regulating germination. In this study, phenology of seedling emergence and of physical dormancy loss was examined for seeds buried at shaded or sunny exposed locations. The role of temperature in regulating dormancy and germination was analysed by incubating seeds in temperature sequences simulating temperatures that seeds experience in nature. The results indicate that most seeds of G. robertianum buried in sunny conditions germinate immediately after physical dormancy loss in summer. Seeds buried in shaded conditions also lose physical dormancy mainly during summer, but remain physiologically dormant and do not germinate until late winter or early spring. Besides physical dormancy, seeds of G. robertianum also initially have a high level of physiological dormancy, which is reduced during dry storage. Physiological dormancy is reduced through chilling in winter, thus enabling the seeds to germinate at low temperatures. We conclude that a complex combination of physical and physiological dormancy ensures that G. robertianum seeds germinate in summer at exposed sites and in early spring at shaded sites. PMID:20701699

Vandelook, F; Van Assche, J A

2010-09-01

164

Physical dormancy in seeds: a game of hide and seek?  

PubMed

Historically, 'physical dormancy', or 'hard seededness', where seeds are prevented from germinating by a water-impermeable seed coat, is viewed as a dormancy mechanism. However, upon water uptake, resumption of metabolism leads to the unavoidable release of volatile by-products, olfactory cues that are perceived by seed predators. Here, we examine the hypothesis that hard seeds are an anti-predator trait that evolved in response to powerful selection by small mammal seed predators. Seeds of two legume species with dimorphic seeds ('hard' and 'soft'), Robinia pseudoacacia and Vicia sativa, were offered to desert hamsters (Phodopus roborovskii) in a series of seed removal studies examining the differences in seed harvest between hard and soft seeds. Volatile compounds emitted by dry and imbibed soft seeds were identified by headspace gas chromatography-mass spectrometry (GC-MS). Fourteen main volatile compounds were identified, and hamsters readily detected both buried imbibed seeds and an artificial 'volatile cocktail' that mimicked the scent of imbibed seeds, but could not detect buried hard or dry soft seeds. We argue that physical dormancy has evolved to hide seeds from mammalian predators. This hypothesis also helps to explain some otherwise puzzling features of hard seeds and has implications for seed dispersal. PMID:23421728

Paulsen, Torbjørn Rage; Colville, Louise; Kranner, Ilse; Daws, Matthew I; Högstedt, Göran; Vandvik, Vigdis; Thompson, Ken

2013-04-01

165

INTERIOR VIEW OF ENTRANCE TO LABORATORY, SHOWING HANDHAMMERED ALUMINUM DOORS ...  

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

INTERIOR VIEW OF ENTRANCE TO LABORATORY, SHOWING HAND-HAMMERED ALUMINUM DOORS AND MARBLE. NOTE ALUMINUM LIGHT FIXTURE - Alcoa Research Laboratory, Freeport Road, New Kensington, Westmoreland County, PA

166

7. INTERIOR, VIEW FROM ENTRANCE TOWARD ENCLOSED STAIRS AND REAR ...  

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

7. INTERIOR, VIEW FROM ENTRANCE TOWARD ENCLOSED STAIRS AND REAR DOOR - Mulliken-Spragins Tenant House, National Museum of American History, Smithsonian Institution, Washington, District of Columbia, DC

167

?Cat FACE? SCAR ON LONGLEAF PINE TREE, OVERHILLS HISTORIC ENTRANCE ...  

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

?Cat FACE? SCAR ON LONGLEAF PINE TREE, OVERHILLS HISTORIC ENTRANCE ROAD, FACING NORTHEAST - Overhills, Fort Bragg Military Reservation, Approximately 15 miles NW of Fayetteville, Overhills, Harnett County, NC

168

6. WEST FRONT DETAIL, SHOWING AUTO ENTRANCE, WINDOWS AND MASONRY. ...  

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

6. WEST FRONT DETAIL, SHOWING AUTO ENTRANCE, WINDOWS AND MASONRY. VIEW TO NORTH. - Commercial & Industrial Buildings, Dubuque Oat Meal Mill Powerhouse, Seventh & Washington Streets, Dubuque, Dubuque County, IA

169

Physical Dormancy in Seeds of the Holoparasitic Angiosperm Cuscuta australis (Convolvulaceae, Cuscuteae): Dormancy-breaking Requirements, Anatomy of the Water Gap and Sensitivity Cycling  

PubMed Central

Background and Aims Dormancy in seeds of Cuscuta (Convolvulaceae, tribe Cuscuteae) is due to a water-impermeable seed coat (physical dormancy). In nondormant seeds of several species of this family, bulges adjacent to the micropyle have been identified as the initial route of water entry into seeds (water gap). However, there are claims that water enters seeds of Cuscuta spp. via the entire seed coat. Although several studies have been done on seed coat anatomy of Cuscuta, none has identified and/or characterized the morphology/anatomy of a water gap. Thus, the primary aim of this research was to identify and describe the morphology and anatomy of the water gap in seeds of Cuscuta australis. It was also determined if sensitivity cycling to dormancy-breaking treatments occurs in seeds of this species. Methods Light microscopy, scanning electron microscopy, tissue-sectioning and dye-tracking and blocking experiments were used to investigate the morphology and anatomy of the water gap. Treatments simulating natural conditions were used to break seed dormancy. Storage of seeds at different temperatures was tested for their effect on sensitivity to dormancy-breaking treatment. Key Results Dormancy-breaking treatments caused the tightly closed hilar fissure to open. Staining was observed in cells below the hilum area but not in those below the seed coat away from the hilum. Sensitivity to dormancy-breaking treatment was induced by storing seeds dry and reduced by storing them wet. Conclusions Whereas bulges adjacent to the micropyle act as the water gap in other species of Convolvulaceae with physical dormancy, the hilar fissure serves this function in Cuscuta. Cuscuta australis can cycle between insensitivity ? sensitivity to dormancy-breaking treatments. PMID:18453546

Jayasuriya, K. M. G. Gehan; Baskin, Jerry M.; Geneve, Robert L.; Baskin, Carol C.; Chien, Ching-Te

2008-01-01

170

Dehydration and vernalization treatments identify overlapping molecular networks impacting endodormancy maintenance in leafy spurge crown buds.  

PubMed

Leafy spurge (Euphorbia esula L.) is a herbaceous perennial weed that reproduces vegetatively from an abundance of underground adventitious buds (UABs), which undergo well-defined phases of seasonal dormancy (para-, endo-, and ecodormancy). In this study, the effects of dehydration stress on vegetative growth and flowering potential from endodormant UABs of leafy spurge was monitored. Further, microarray analysis was used to identify critical signaling pathways of transcriptome profiles associated with endodormancy maintenance in UABs. Surprisingly, only 3-day of dehydration stress is required to break the endodormant phase in UABs; however, the dehydration-stress treatment did not induce flowering. Previous studies have shown that prolonged cold treatment of UABs breaks endodormancy and induces a vernalization response leading to flowering. Thus, in this study, comparing transcriptome data from UABs exposed to short-term dehydration and vernalization provided a unique approach to identify overlapping molecular mechanisms involved in endodormancy maintenance and floral competence. Analysis of transcriptome data associated with breaking endodormancy by both environmental treatments identified LEC1, PHOTOSYSTEM I RC, and brassinosteroids as common central hubs of upregulated genes, while DREB1A, CBF2, GPA1, MYC2, bHLH, BZIP, and flavonoids were identified as common central hubs of downregulated genes. The majority of over-represented gene sets common to breaking endodormancy by dehydration stress and vernalization were downregulated and included pathways involved in hormone signaling, chromatin modification, and circadian rhythm. Additionally, the over-represented gene sets highlighted pathways involved in starch and sugar degradation and biogenesis of carbon skeletons, suggesting a high metabolic activity is necessary during the endodormant phase. The data presented in this study helped to refine our previous model for dormancy regulation. PMID:21789635

Do?ramac?, Münevver; Horvath, David P; Christoffers, Michael J; Anderson, James V

2011-12-01

171

Sympatric species of Hibbertia (Dilleniaceae) vary in dormancy break and germination requirements: implications for classifying morphophysiological dormancy in Mediterranean biomes  

PubMed Central

Background and Aims Several ecologically important plant families in Mediterranean biomes have seeds with morphophysiological dormancy (MPD) but have been poorly studied. The aim of this study was to understand the seed ecology of these species by focusing on the prominent, yet intractably dormant Australian genus Hibbertia. It was hypothesized that the slow germination in species of this genus is caused by a requirement for embryo growth inside the seed before germination, and that initiation of embryo growth is reliant upon a complex sequence of environmental cues including seasonal fluctuations in temperature and moisture, and an interplay with light and smoke. Using the results, the classification of the MPD level in species of Hibbertia is considered. Methods Four species of Hibbertia in winter rainfall south-western Australia were selected. These species, whilst differing in geographic distributions, are variously sympatric, and all are important understorey components of plant communities. The following aspects related to dormancy break, embryo growth and germination were investigated: temperature and moisture requirements; effects of karrikinolide, gibberellic acid and aerosol smoke; and phenology. Key Results Following exposure to wet/dry cycles at low or high temperatures, embryo growth and germination occurred, albeit slowly in all species at low temperatures when moisture was unlimited, corresponding to winter in south-west Australia. Photo regime influenced germination only in H. racemosa. Aerosol smoke triggered substantial germination during the 1st germination season in H. huegelii and H. hypericoides. Conclusions Although the study species are con-generic, sympatric and produce seeds of identical morphology, they possessed different dormancy-break and germination requirements. The physiological component of MPD was non-deep in H. racemosa but varied in the other three species where more deeply dormant seeds required >1 summer to overcome dormancy and, thus, germination was spread over time. Embryos grew during winter, but future studies need to resolve the role of cold versus warm stratification by using constant temperature regimes. To include Mediterranean species with MPD, some modifications to the current seed-dormancy classification system may need consideration: (a) wet/dry conditions for warm stratification and (b) a relatively long period for warm stratification. These outcomes have important implications for improving experimental approaches to resolve the effective use of broadcast seed for ecological restoration. PMID:22362661

Hidayati, Siti N.; Walck, Jeffrey L.; Merritt, David J.; Turner, Shane R.; Turner, David W.; Dixon, Kingsley W.

2012-01-01

172

The role of temperature in the regulation of dormancy and germination of two related summer-annual mudflat species  

Microsoft Academic Search

Dormancy and germination requirements were investigated in seeds (achenes) of the closely-related annuals Bidens cernua and Bidens tripartita (Asteraceae). They showed clear differences in their temperature requirements for germination, their dormancy and seed longevity in soil. In B. cernua seeds, primary dormancy was relieved when stratified at 3, 8, and 12°C, as seeds germinated to a maximum of more than

Markus Brändel

2004-01-01

173

Respiration and hemoglobin function in the giant African bullfrog Pyxicephalus adspersus Tschudi (Anura: Pyxicephalidae) during rest, exercise and dormancy  

Microsoft Academic Search

The survival strategies of frogs exposed to harsh conditions include various forms of dormancy. Giant bullfrogs Pyxicephalus adspersus subjected to slow desiccation without access to moist substrata over winter in cocoons during dormancy. We found that Pyxicephalus can survive long periods of dormancy in soil without forming cocoons. With virtually no information available on the associated respiratory adaptations, we measured

W. J. van Aardt; Roy E. Weber

2010-01-01

174

The promotive effect of combustion products from plant vegetation on the release of seeds from dormancy  

Microsoft Academic Search

In darkness, dormancy was imposed on seeds of lettuce (Lactuca sativa L. cv. Grand rapids) by high temperature and on seeds of oilseed rape (Brassica napus L. cv. Apex) by osmotic stress using polyethylene glycol (PEG 8000). In both cases, dormancy was broken by incubating the seeds in aqueous extracts of combustion products from Salix viminalis wood chips or Themeda

M. A. Thornton; T. H. Thomas; N. C. B. Peters

1999-01-01

175

Some reflections on the relationship between endogenous hormones and light-mediated seed dormancy  

Microsoft Academic Search

The relationships between phytochrome and endogenous hormones in the light-mediated control of seed dormancy are discussed. It is concluded that gibberellins are primarily involved in post-dormancy metabolic processes leading to embryo growth and radicle emergence, such as food reserve mobilisation and endosperm softening. Evidence is considered that germination inhibitors, particularly abscisic acid, are involved in the establishment and maintenance of

Tudor H. Thomas

1992-01-01

176

Environmental regulation of dormancy loss in seeds of Lomatium dissectum (Apiaceae)  

Microsoft Academic Search

†Background and Aims Lomatium dissectum (Apiaceae) is a perennial, herbaceous plant of wide distribution in Western North America. At the time of dispersal, L. dissectum seeds are dormant and have under-developed embryos. The aims of this work were to determine the requirements for dormancy break and germination, to characterize the type of seed dormancy, and to determine the effect of

Melissa Scholten; Jacklyn Donahue; Nancy L. Shaw; Marcelo D. Serpe

2009-01-01

177

Prolonged pupal dormancy is associated with significant fitness cost for adults of Rhagoletis cerasi (Diptera: Tephritidae).  

PubMed

In temperate areas, dormancy (diapause and/or quiescence) enables herbivorous insect species to persist and thrive by synchronizing growth and reproduction with the seasonal phenology of their host plants. Within-population variability in dormancy increases survival chances under unpredictable environmental changes. However, prolonged dormancy may be costly, incurring trade-offs in important adult fitness traits such as life span and reproduction. We used the European cherry fruit fly, Rhagoletis cerasi, a stenophagous, univoltine species that overwinters in the pupal stage for usually one or more years to test the hypotheses that prolonged dormancy of pupae has trade-offs with body size, survival and reproduction of the resulting adults. We used two geographically isolated populations of R. cerasi to compare the demographic traits of adults obtained from pupae subjected to one or two cycles of warm-cold periods (annual and prolonged dormancy respectively). Regardless of population, adults from pupae that experienced prolonged dormancy were larger than counterparts emerging within 1year. Prolonged dormancy did not affect adult longevity but both lifetime fecundity and oviposition were significantly decreased. Extension of the life cycle of some individuals in R. cerasi populations in association with prolonged dormancy is likely a bet-hedging strategy. PMID:22684113

Moraiti, Cleopatra A; Nakas, Christos T; Papadopoulos, Nikos T

2012-08-01

178

Phoenix clones: recovery after long-term defoliation-induced dormancy  

Microsoft Academic Search

Many long-lived plants are known to prolong dormancy in response to abiotic stresses such as drought. We are unaware, however, of any reports of plants prolonging dormancy in response to biotic stresses such as herbivory. We monitored 140 putative Solidago missouriensis clones (hereafter clones) ‡ 13 years before, during and after intense defoliation by the specialist herbivore Trirhabda canadensis. Eight

Patrice A. Morrow; Joel P. Olfelt

2003-01-01

179

On the role of abscisic acid in seed dormancy of red rice  

Microsoft Academic Search

Abscisic acid (ABA) is commonly assumed to be the primary effector of seed dormancy, but conclusive evidence for this role is lacking. This paper reports on the relationships occurring in red rice between ABA and seed dormancy. Content of free ABA in dry and imbibed caryopses, both dormant and after-ripened, the effects of inhibitors, and the ability of applied ABA

Alberto Gianinetti; Paolo Vernieri

2010-01-01

180

7. CLOSEUP VIEW OF ENTRANCE TO BUILDING NO. 33 FACING ...  

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

7. CLOSE-UP VIEW OF ENTRANCE TO BUILDING NO. 33 FACING EAST. VIEW SHOWS CONCRETE PLANTING BOXES ON EACH SIDE OF ENTRANCE AND CONCRETE CANOPY OVERHANG ABOVE. - U.S. Naval Base, Pearl Harbor, Marine Barracks, West Loch, B Avenue near Arizona Road, Pearl City, Honolulu County, HI

181

15. Interior view of main entrance hallway looking at opposite ...  

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

15. Interior view of main entrance hallway looking at opposite entrance; showing display cases, cashier's window, and doors to public restrooms; near southeast corner of upper level; view to north. - Ellsworth Air Force Base, Mess Hall & Administration Building, 1301 Ellsworth Street, Blackhawk, Meade County, SD

182

Does Delaying Kindergarten Entrance Give Children a Head Start?  

ERIC Educational Resources Information Center

The rising trend in the minimum entrance age for kindergarten in the US has been motivated by findings from cross-sectional studies that older entrants have more favorable school outcomes compared to younger entrants. However, these studies fail to account for endogeneity in entrance age resulting from parental choice, leading to biased estimates…

Datar, Ashlesha

2006-01-01

183

DETAIL OF MAIN ENTRANCE ON NORTH SIDE; NOTE GOTHIC DETAILING ...  

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

DETAIL OF MAIN ENTRANCE ON NORTH SIDE; NOTE GOTHIC DETAILING ON ENTRANCE PAVILION, PARAPET: ORIGINAL, PORTION OF THIS BUILDING WAS DESIGNED BY RATH PLANT ENGINEER J.S. BARTLEY IN 1925 - Rath Packing Company, Administration Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

184

Love and Work: The Legacy of Early University Entrance  

ERIC Educational Resources Information Center

This is the second follow-up study of the Early Entrance Program at the University of Washington. Ninety-five individuals (45%) participated. Respondents overwhelmingly chose early university entrance because they were excited to learn; many also praised the peer group, intellectual stimulation, and faculty and staff support. Some reported feeling…

Noble, Kathleen D.; Vaughan, Robert C.; Chan, Christina; Childers, Sarah; Chow, Bryan; Federow, Ariel; Hughes, Sean

2007-01-01

185

Domain-induced budding in buckling membranes.  

PubMed

We present a phase field model on buckling membranes to analyze phase separation and budding on soft membranes. By numerically integrating dynamic equations, it turns out that the formation of caps is greatly influenced by the presence of a little excess area due to the surface area constraint. When cap-shaped domains are created, domain coalescence is mainly observed not between domains with same budding directions, but between domains with opposite budding directions, because the bending energy between two domains is larger in the former case. Although we do not introduce spontaneous curvature like Helfrich model, we obtain some suggestions related to the slow dynamics of the phase separation on vesicles. PMID:17712524

Minami, A; Yamada, K

2007-08-01

186

Ants' learning of nest entrance characteristics (Hymenoptera, Formicidae).  

PubMed

Young workers, experimentally removed from their nest and set in front of it, are not very good at finding the nest entrance and entering the nest. I examined how young ants learn their nest entrance characteristics, dealing only with the entrance sensu stricto, not with its vicinity. I observed that young ants have the innate behavior of trying to exit and re-enter their nest. I found that they are imprinted with the nest entrance odor while they are still living inside their nest and that they learn the visual aspect of their nest entrances, thanks to operant conditioning, when they exit their nest and succeed in re-entering in the course of their first short trips outside. PMID:24059564

Cammaerts, M C

2014-02-01

187

Possible Role of Volatile Fatty Acids and Abscisic Acid in the Dormancy of Oats  

PubMed Central

Species of Avena differ markedly in their levels of pre- and post-harvest dormancy. These species offer the opportunity of determining if dormancy is related to the endogenous level of growth inhibitor. Germinability in two species of differing levels of dormancy, common oat Avena sativa L., and wild oat Avena fatua L. was assessed as were the contents of abscisic acid and volatile fatty acids of chain length C6-C10. In A. sativa which did not possess postharvest dormancy there was no correlation between germination and inhibitor levels but in A. fatua the relationship between the content of fatty acid and dormancy was good. The loss of these fatty acids in dry storage by evaporation could explain after ripening. PMID:16660807

Berrie, Alex M. M.; Buller, David; Don, Ronald; Parker, William

1979-01-01

188

Possible role of volatile Fatty acids and abscisic Acid in the dormancy of oats.  

PubMed

Species of Avena differ markedly in their levels of pre- and post-harvest dormancy. These species offer the opportunity of determining if dormancy is related to the endogenous level of growth inhibitor. Germinability in two species of differing levels of dormancy, common oat Avena sativa L., and wild oat Avena fatua L. was assessed as were the contents of abscisic acid and volatile fatty acids of chain length C(6)-C(10). In A. sativa which did not possess postharvest dormancy there was no correlation between germination and inhibitor levels but in A. fatua the relationship between the content of fatty acid and dormancy was good. The loss of these fatty acids in dry storage by evaporation could explain after ripening. PMID:16660807

Berrie, A M

1979-04-01

189

Wheat ABA-insensitive mutants result in reduced grain dormancy  

PubMed Central

This paper describes the isolation of wheat mutants in the hard red spring Scarlet resulting in reduced sensitivity to the plant hormone abscisic acid (ABA) during seed germination. ABA induces seed dormancy during embryo maturation and inhibits the germination of mature seeds. Wheat sensitivity to ABA gradually decreases with dry after-ripening. Scarlet grain normally fails to germinate when fully dormant, shows ABA sensitive germination when partially after-ripened, and becomes ABA insensitive when after-ripened for 8–12 months. Scarlet ABA-insensitive (ScABI) mutants were isolated based on the ability to germinate on 5 µM ABA after only 3 weeks of after-ripening, a condition under which Scarlet would fail to germinate. Six independent seed-specific mutants were recovered. ScABI 1, ScABI2, ScABI3 and ScABI4 are able to germinate more efficiently than Scarlet at up to 25 µM ABA. The two strongest ABA insensitive lines, ScABI3 and ScABI4, both proved to be partly dominant suggesting that they result from gain-of-function mutations. The ScABI1, ScABI2, ScABI3, ScABI4, and ScABI5 mutants after-ripen more rapidly than Scarlet. Thus, ABA insensi-tivity is associated with decreased grain dormancy in Scarlet wheat. This suggests that ABA sensitivity is an important factor controlling grain dormancy in wheat, a trait that impacts seedling emergence and pre-harvest sprouting resistance.

Schramm, Elizabeth C.; Nelson, Sven K.

2014-01-01

190

Short Photoperiod Induces Dormancy in Lotus (Nelumbo nucifera)  

PubMed Central

• Background and Aims Lotus (Nelumbo nucifera) has been cultivated as an ornamental and food plant in Japan for more than 1000 years. As large areas are required for its cultivation (approximately 2?m2 per plant), physiological research, such as into the effect of environmental factors on dormancy, has not been well studied until recently. In this paper, seedlings were used to examine environmental factors affecting dormancy induction. • Methods In a first experiment, seeds were sown from 6 April to 6 October at 2-month intervals, and cultivated for 2 months in an unheated greenhouse. In a second experiment, seeds were prepared for germination on 16 November and 16 May and the seedlings were grown at 25 or 30?°C under natural daylength in phytotron growth rooms. After 1 month, the seedlings were cultivated at 20, 25 or 30?°C for a further month. The number of leaves and rhizome branches on the main stem were counted, and growth of rhizomes on the main stem was calculated using a rhizome enlargement index (= maximum internode diameter/internode length) after 2 months of culture in both experiments. • Key Results Rhizomes elongated without enlargement when the seeds were sown in April and June. Sowing the seeds in August and October resulted in rhizome enlargement from the tenth and fifth internodes, respectively. Rhizomes enlarged in the November-sowing but elongated in the May-sowing irrespective of temperature treatments under natural daylength in the phytotron rooms. The seedlings cultivated from May at 25–30?°C for 2 months had more leaves, and more rhizome branches and nodes than those cultivated from November. • Conclusions Short days led to induced dormancy in lotus. PMID:16287906

MASUDA, JUN-ICHIRO; URAKAWA, TOSHIHIRO; OZAKI, YUKIO; OKUBO, HIROSHI

2006-01-01

191

Environmental regulation of dormancy loss in seeds of Lomatium dissectum (Apiaceae)  

PubMed Central

Background and Aims Lomatium dissectum (Apiaceae) is a perennial, herbaceous plant of wide distribution in Western North America. At the time of dispersal, L. dissectum seeds are dormant and have under-developed embryos. The aims of this work were to determine the requirements for dormancy break and germination, to characterize the type of seed dormancy, and to determine the effect of dehydration after embryo growth on seed viability and secondary dormancy. Methods The temperature requirements for embryo growth and germination were investigated under growth chamber and field conditions. The effect of GA3 on embryo growth was also analysed to determine the specific type of seed dormancy. The effect of dehydration on seed viability and induction of secondary dormancy were tested in seeds where embryos had elongated about 4-fold their initial length. Most experiments examining the nature of seed dormancy were conducted with seeds collected at one site in two different years. To characterize the degree of variation in dormancy-breaking requirements among seed populations, the stratification requirements of seeds collected at eight different sites were compared. Key Results Embryo growth prior to and during germination occurred at temperatures between 3 and 6 °C and was negligible at stratification temperatures of 0·5 and 9·1 °C. Seeds buried in the field and exposed to natural winter conditions showed similar trends. Interruption of the cold stratification period by 8 weeks of dehydration decreased seed viability by about 30 % and induced secondary dormancy in the remaining viable seeds. Comparison of the cold stratification requirements of different seed populations indicates that seeds collected from moist habitats have longer cold stratification requirements that those from semiarid environments. Conclusions Seeds of L. dissectum have deep complex morphophysiological dormancy. The requirements for dormancy break and germination reflect an adaptation to trigger germination in late winter. PMID:19233890

Scholten, Melissa; Donahue, Jacklyn; Shaw, Nancy L.; Serpe, Marcelo D.

2009-01-01

192

Cancer dormancy: time to explore its clinical relevance  

PubMed Central

Dormant disseminated cancer cells, arrested and nonproliferating, are “good” cancer cells because there is no need to worry unless they resume growth. The mechanisms by which dormant disseminated cancer cells are put to sleep at distant sites and re-awakened are poorly understood. Moreover, it is not clear whether re-awakened cancer cells have a role in disease courses. Cyrus Ghajar and colleagues identified a mechanism of dormancy and growth resumption that might become important when more closely linked to clinical reality. PMID:24359585

2013-01-01

193

Semliki Forest Virus Budding: Assay, Mechanisms, and Cholesterol Requirement  

Microsoft Academic Search

All enveloped viruses must bud through a cellular membrane in order to acquire their lipid bilayer, but little is known about this important stage in virus biogenesis. We have developed a quantitative biochemical assay to monitor the budding of Semliki Forest virus (SFV), an enveloped alphavirus that buds from the plasma membrane in a reaction requiring both viral spike proteins

YANPING E. LU; MARGARET KIELIAN

2000-01-01

194

Dormancy Is Not Necessary or Sufficient for Bacterial Persistence  

PubMed Central

The antibiotic tolerances of bacterial persisters have been attributed to transient dormancy. While persisters have been observed to be growth inhibited prior to antibiotic exposure, we sought to determine whether such a trait was essential to the phenotype. Furthermore, we sought to provide direct experimental evidence of the persister metabolic state so as to determine whether the common assumption of metabolic inactivity was valid. Using fluorescence-activated cell sorting (FACS), a fluorescent indicator of cell division, a fluorescent measure of metabolic activity, and persistence assays, we found that bacteria that are rapidly growing prior to antibiotic exposure can give rise to persisters and that a lack of replication or low metabolic activity prior to antibiotic treatment simply increases the likelihood that a cell is a persister. Interestingly, a lack of significant growth or metabolic activity does not guarantee persistence, as the majority of even “dormant” subpopulations (>99%) were not persisters. These data suggest that persistence is far more complex than dormancy and point to additional characteristics needed to define the persister phenotype. PMID:23629720

Orman, Mehmet A.

2013-01-01

195

Overexpression of the kiwifruit SVP3 gene affects reproductive development and suppresses anthocyanin biosynthesis in petals, but has no effect on vegetative growth, dormancy, or flowering time  

PubMed Central

SVP-like MADS domain transcription factors have been shown to regulate flowering time and both inflorescence and flower development in annual plants, while having effects on growth cessation and terminal bud formation in perennial species. Previously, four SVP genes were described in woody perennial vine kiwifruit (Actinidia spp.), with possible distinct roles in bud dormancy and flowering. Kiwifruit SVP3 transcript was confined to vegetative tissues and acted as a repressor of flowering as it was able to rescue the Arabidopsis svp41 mutant. To characterize kiwifruit SVP3 further, ectopic expression in kiwifruit species was performed. Ectopic expression of SVP3 in A. deliciosa did not affect general plant growth or the duration of endodormancy. Ectopic expression of SVP3 in A. eriantha also resulted in plants with normal vegetative growth, bud break, and flowering time. However, significantly prolonged and abnormal flower, fruit, and seed development were observed, arising from SVP3 interactions with kiwifruit floral homeotic MADS-domain proteins. Petal pigmentation was reduced as a result of SVP3-mediated interference with transcription of the kiwifruit flower tissue-specific R2R3 MYB regulator, MYB110a, and the gene encoding the key anthocyanin biosynthetic step, F3GT1. Constitutive expression of SVP3 had a similar impact on reproductive development in transgenic tobacco. The flowering time was not affected in day-neutral and photoperiod-responsive Nicotiana tabacum cultivars, but anthesis and seed germination were significantly delayed. The accumulation of anthocyanin in petals was reduced and the same underlying mechanism of R2R3 MYB NtAN2 transcript reduction was demonstrated. PMID:24948678

Wu, Rongmei; Wang, Tianchi; McGie, Tony; Voogd, Charlotte; Allan, Andrew C.; Hellens, Roger P.; Varkonyi-Gasic, Erika

2014-01-01

196

Overexpression of the kiwifruit SVP3 gene affects reproductive development and suppresses anthocyanin biosynthesis in petals, but has no effect on vegetative growth, dormancy, or flowering time.  

PubMed

SVP-like MADS domain transcription factors have been shown to regulate flowering time and both inflorescence and flower development in annual plants, while having effects on growth cessation and terminal bud formation in perennial species. Previously, four SVP genes were described in woody perennial vine kiwifruit (Actinidia spp.), with possible distinct roles in bud dormancy and flowering. Kiwifruit SVP3 transcript was confined to vegetative tissues and acted as a repressor of flowering as it was able to rescue the Arabidopsis svp41 mutant. To characterize kiwifruit SVP3 further, ectopic expression in kiwifruit species was performed. Ectopic expression of SVP3 in A. deliciosa did not affect general plant growth or the duration of endodormancy. Ectopic expression of SVP3 in A. eriantha also resulted in plants with normal vegetative growth, bud break, and flowering time. However, significantly prolonged and abnormal flower, fruit, and seed development were observed, arising from SVP3 interactions with kiwifruit floral homeotic MADS-domain proteins. Petal pigmentation was reduced as a result of SVP3-mediated interference with transcription of the kiwifruit flower tissue-specific R2R3 MYB regulator, MYB110a, and the gene encoding the key anthocyanin biosynthetic step, F3GT1. Constitutive expression of SVP3 had a similar impact on reproductive development in transgenic tobacco. The flowering time was not affected in day-neutral and photoperiod-responsive Nicotiana tabacum cultivars, but anthesis and seed germination were significantly delayed. The accumulation of anthocyanin in petals was reduced and the same underlying mechanism of R2R3 MYB NtAN2 transcript reduction was demonstrated. PMID:24948678

Wu, Rongmei; Wang, Tianchi; McGie, Tony; Voogd, Charlotte; Allan, Andrew C; Hellens, Roger P; Varkonyi-Gasic, Erika

2014-09-01

197

Temperature rather than photoperiod controls growth cessation and dormancy in Sorbus species  

PubMed Central

Environmental regulation of growth and dormancy of four Sorbus genotypes was studied in controlled environments. Emphasis was placed on assessment of the presence and nature of the deficient photoperiodic dormancy regulation system that has previously been reported for some woody Rosaceae species. Two genotypes of Sorbus aucuparia L. maintained indeterminate growth for 8 weeks and 9 weeks at temperatures of 15 °C and 21 °C in both 20 h and 10 h photoperiods, while at 9 °C, in the same photoperiodic conditions, they immediately ceased growing. At the higher temperatures, initiation of new leaves (nodes) was unaffected by photoperiod, while internode elongation was significantly enhanced by long days (LD). However, even after prolonged exposure to 9 °C, most plants resumed growth when moved to high temperature and LD, indicating a shallow state of dormancy. Seedlings of Sorbus intermedia (J. F. Ehrh.) Pers. and micro-propagated plantlets of S. commixta Hedl. ‘Dodong’ were also unaffected by photoperiod during primary growth, but failed to elongate and gradually became dormant regardless of temperature and day-length conditions. However, after chilling and breaking of dormancy, the plants elongated vigorously but changed to a determinate mode of growth. Furthermore, a temperature of 9 °C was found to be fully effective for breaking dormancy in S. intermedia plants. It is concluded that deficient photoperiodic dormancy control seems widespread in the Rosaceae and that, in such plants, both dormancy induction and release is brought about by low temperature. The potential impacts of climate change on such trees are discussed. PMID:21862485

Heide, Ola M.

2011-01-01

198

Temperature rather than photoperiod controls growth cessation and dormancy in Sorbus species.  

PubMed

Environmental regulation of growth and dormancy of four Sorbus genotypes was studied in controlled environments. Emphasis was placed on assessment of the presence and nature of the deficient photoperiodic dormancy regulation system that has previously been reported for some woody Rosaceae species. Two genotypes of Sorbus aucuparia L. maintained indeterminate growth for 8 weeks and 9 weeks at temperatures of 15 °C and 21 °C in both 20 h and 10 h photoperiods, while at 9 °C, in the same photoperiodic conditions, they immediately ceased growing. At the higher temperatures, initiation of new leaves (nodes) was unaffected by photoperiod, while internode elongation was significantly enhanced by long days (LD). However, even after prolonged exposure to 9 °C, most plants resumed growth when moved to high temperature and LD, indicating a shallow state of dormancy. Seedlings of Sorbus intermedia (J. F. Ehrh.) Pers. and micro-propagated plantlets of S. commixta Hedl. 'Dodong' were also unaffected by photoperiod during primary growth, but failed to elongate and gradually became dormant regardless of temperature and day-length conditions. However, after chilling and breaking of dormancy, the plants elongated vigorously but changed to a determinate mode of growth. Furthermore, a temperature of 9 °C was found to be fully effective for breaking dormancy in S. intermedia plants. It is concluded that deficient photoperiodic dormancy control seems widespread in the Rosaceae and that, in such plants, both dormancy induction and release is brought about by low temperature. The potential impacts of climate change on such trees are discussed. PMID:21862485

Heide, Ola M

2011-11-01

199

A Cellular Automaton Model for Tumor Dormancy: Emergence of a Proliferative Switch  

PubMed Central

Malignant cancers that lead to fatal outcomes for patients may remain dormant for very long periods of time. Although individual mechanisms such as cellular dormancy, angiogenic dormancy and immunosurveillance have been proposed, a comprehensive understanding of cancer dormancy and the “switch” from a dormant to a proliferative state still needs to be strengthened from both a basic and clinical point of view. Computational modeling enables one to explore a variety of scenarios for possible but realistic microscopic dormancy mechanisms and their predicted outcomes. The aim of this paper is to devise such a predictive computational model of dormancy with an emergent “switch” behavior. Specifically, we generalize a previous cellular automaton (CA) model for proliferative growth of solid tumor that now incorporates a variety of cell-level tumor-host interactions and different mechanisms for tumor dormancy, for example the effects of the immune system. Our new CA rules induce a natural “competition” between the tumor and tumor suppression factors in the microenvironment. This competition either results in a “stalemate” for a period of time in which the tumor either eventually wins (spontaneously emerges) or is eradicated; or it leads to a situation in which the tumor is eradicated before such a “stalemate” could ever develop. We also predict that if the number of actively dividing cells within the proliferative rim of the tumor reaches a critical, yet low level, the dormant tumor has a high probability to resume rapid growth. Our findings may shed light on the fundamental understanding of cancer dormancy. PMID:25329892

Chen, Duyu; Jiao, Yang; Torquato, Salvatore

2014-01-01

200

Co-adaptation of seed dormancy and flowering time in the arable weed Capsella bursa-pastoris (shepherd's purse)  

PubMed Central

Background and Aims The duration of the plant life cycle is an important attribute that determines fitness and coexistence of weeds in arable fields. It depends on the timing of two key life-history traits: time from seed dispersal to germination and time from germination to flowering. These traits are components of the time to reproduction. Dormancy results in reduced and delayed germination, thus increasing time to reproduction. Genotypes in the arable seedbank predominantly have short time to flowering. Synergy between reduced seed dormancy and reduced flowering time would create stronger contrasts between genotypes, offering greater adaptation in-field. Therefore, we studied differences in seed dormancy between in-field flowering time genotypes of shepherd's purse. Methods Genotypes with early, intermediate or late flowering time were grown in a glasshouse to provide seed stock for germination tests. Secondary dormancy was assessed by comparing germination before and after dark-incubation. Dormancy was characterized separately for seed myxospermy heteromorphs, observed in each genotype. Seed carbon and nitrogen content and seed mass were determined as indicators of seed filling and resource partitioning associated with dormancy. Key Results Although no differences were observed in primary dormancy, secondary dormancy was weaker among the seeds of early-flowering genotypes. On average, myxospermous seeds showed stronger secondary dormancy than non-myxospermous seeds in all genotypes. Seed filling was similar between the genotypes, but nitrogen partitioning was higher in early-flowering genotypes and in non-myxospermous seeds. Conclusions In shepherd's purse, early flowering and reduced seed dormancy coincide and appear to be linked. The seed heteromorphism contributes to variation in dormancy. Three functional groups of seed dormancy were identified, varying in dormancy depth and nitrate response. One of these groups (FG-III) was distinct for early-flowering genotypes. The weaker secondary dormancy of early-flowering genotypes confers a selective advantage in arable fields. PMID:22147546

Toorop, Peter E.; Campos Cuerva, Rafael; Begg, Graham S.; Locardi, Bruna; Squire, Geoff R.; Iannetta, Pietro P. M.

2012-01-01

201

Seed Anatomy and Water Uptake in Relation to Seed Dormancy in Opuntia tomentosa (Cactaceae, Opuntioideae)  

PubMed Central

Background and Aims There is considerable confusion in the literature concerning impermeability of seeds with ‘hard’ seed coats, because the ability to take up (imbibe) water has not been tested in most of them. Seeds of Opuntia tomentosa were reported recently to have a water-impermeable seed coat sensu lato (i.e. physical dormancy), in combination with physiological dormancy. However, physical dormancy is not known to occur in Cactaceae. Therefore, the aim of this study was to determine if seeds of O. tomentosa are water-permeable or water-impermeable, i.e. if they have physical dormancy. Methods The micromorphology of the seed coat and associated structures were characterized by SEM and light microscopy. Permeability of the seed-covering layers was assessed by an increase in mass of seeds on a wet substrate and by dye-tracking and uptake of tritiated water by intact versus scarified seeds. Key Results A germination valve and a water channel are formed in the hilum–micropyle region during dehydration and ageing in seeds of O. tomentosa. The funicular envelope undoubtedly plays a role in germination of Opuntia seeds via restriction of water uptake and mechanical resistance to expansion of the embryo. However, seeds do not exhibit any of three features characteristic of those with physical dormancy. Thus, they do not have a water-impermeable layer(s) of palisade cells (macrosclereids) or a water gap sensu stricto and they imbibe water without the seed coat being disrupted. Conclusions Although dormancy in seeds of this species can be broken by scarification, they have physiological dormancy only. Further, based on information in the literature, it is concluded that it is unlikely that any species of Opuntia has physical dormancy. This is the first integrative study of the anatomy, dynamics of water uptake and dormancy in seeds of Cactaceae subfamily Opuntioideae. PMID:17298989

Orozco-Segovia, A.; Marquez-Guzman, J.; Sanchez-Coronado, M. E.; Gamboa de Buen, A.; Baskin, J. M.; Baskin, C. C.

2007-01-01

202

8. WEST REAR, DETAIL SHOWING SECOND FLOOR ENTRANCE AND WINDOW ...  

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

8. WEST REAR, DETAIL SHOWING SECOND FLOOR ENTRANCE AND WINDOW TREATMENT. See CA-174-B-22 FOR INTERIOR OF SECOND FLOOR LAB AT CENTER. - Hughes Aircraft Company, Engineering-Administration Building, 6775 Centinela Avenue, Los Angeles, Los Angeles County, CA

203

Historical bathymetric changes near the entrance to Grays Harbor, Washington  

SciTech Connect

Large changes in the distribution of sediment near the entrance to Grays Harbor, Washington, have occurred since the long rock jetties were built to confine flow. Spits to the north and south of the entrance have grown, the entrance channel has deepened, and the outer bar has eroded and moved offshore. The shorelines of North Beach and South Beach have experienced significant amounts of both erosion and accretion since the jetties were constructed around the turn of the century. Recently, the erosion rate at South Beach has increased and, because Half Moon Bay is growing at the expense of the shoreward side of Point Chehalis, the vegetated portion of the spit is now less than 350 ft wide at the narrowest section. The US Army Corps of Engineers, Seattle District, requested that Battelle/Marine Sciences Laboratory evaluate long-term trends in erosion near the entrance to Grays Harbor.

Burch, T.L.; Sherwood, C.R. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

1992-12-01

204

31. VIEW OF CONCRETE SLAB AT WEST ENTRANCE OF WALKWAY. ...  

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

31. VIEW OF CONCRETE SLAB AT WEST ENTRANCE OF WALKWAY. '1944 JOE LANDETA' SCRATCHED INTO FRESH CONCRETE. March 1987 - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

205

INTERIOR VIEW SHOWING MAIN ENTRANCE DOOR INTO SITTING ROOM AND ...  

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

INTERIOR VIEW SHOWING MAIN ENTRANCE DOOR INTO SITTING ROOM AND DOOR TO PASSAGEWAY AND FERRY BUILDING IN DISTANCE - Ellis Island, New Immigration Building, New York Harbor, New York, New York County, NY

206

Perspective view of main entrance, north façade with two story ...  

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

Perspective view of main entrance, north façade with two story square tower, Note medical cross made of wood on tower, originally there were four. - Richmond Field Hospital, 1330 Cutting Boulevard, Richmond, Contra Costa County, CA

207

View from western bridge portal along entrance road, softball fields ...  

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

View from western bridge portal along entrance road, softball fields to right and hospital complex in distance - New York State Soldiers & Sailors Home, Department of Veterans Affairs Medical Center, 76 Veterans Avenue, Bath, Steuben County, NY

208

24. LAUNCH CONTROL CAPSULE. ENTRANCE TO ACOUSTICAL ENCLOSURE. SHOCK ISOLATOR ...  

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

24. LAUNCH CONTROL CAPSULE. ENTRANCE TO ACOUSTICAL ENCLOSURE. SHOCK ISOLATOR AT FAR LEFT. VIEW TO NORTH. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

209

72. Detail of keystone emblem over the main entrance to ...  

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

72. Detail of keystone emblem over the main entrance to the Carpenter's Union Hall. The inscription translates 'Labor conquers all.' - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

210

3. View of entrance to cellar and heavy timber framing ...  

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

3. View of entrance to cellar and heavy timber framing of the wine press building, looking southeast. - Merkel Farmstead, Wine Press Building, 8570 Louella Lane, south side of U.S. Route 64, Shiloh, St. Clair County, IL

211

1. EXTERIOR VIEW, LOOKING EAST, WITH ENTRANCES AND SIDE ELEVATIONS ...  

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

1. EXTERIOR VIEW, LOOKING EAST, WITH ENTRANCES AND SIDE ELEVATIONS ALONG THE OLD BANKHEAD HIGHWAY (NOW 20TH STREET) AND ELLIOTT BOULEVARD - G. W. Posey Store, Twentieth Street & Elliot Boulevard, Jasper, Walker County, AL

212

1. VIEW OF THE ENTRANCE TO THE HATCH ADIT (FEATURE ...  

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

1. VIEW OF THE ENTRANCE TO THE HATCH ADIT (FEATURE B-28), FACING WEST. (OCTOBER, 1995) - Nevada Lucky Tiger Mill & Mine, Hatch Adit, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

213

2. EXTERIOR VIEW OF HILLSIDE PLANT ENTRANCE. NOTE CONTRAST BETWEEN ...  

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

2. EXTERIOR VIEW OF HILLSIDE PLANT ENTRANCE. NOTE CONTRAST BETWEEN THIS MODERN ADDITION AND THE OLDER SECTION OF THE MILL VISIBLE IN HAER No. GA-130-1. - Hillside Cotton Mill, 1300 Brownwood Avenue, La Grange, Troup County, GA

214

3. FIRST FLOOR, FRONT ROOM WITH ENTRANCE DOORS ON THE ...  

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

3. FIRST FLOOR, FRONT ROOM WITH ENTRANCE DOORS ON THE EAST WALL - Penn School Historic District, Butler Building, SC Route 37, 1 mile South of Frogmore, St. Helena Island, Frogmore, Beaufort County, SC

215

1. GENERAL VIEW OF ENTRANCE INTO ALUMINUM CITY TERRACE ALONG ...  

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

1. GENERAL VIEW OF ENTRANCE INTO ALUMINUM CITY TERRACE ALONG EAST HILL DRIVE. BUILDING 1 ON RIGHT, BUILDING 2 ON LEFT, FACING EAST. - Aluminum City Terrace, East Hill Drive, New Kensington, Westmoreland County, PA

216

1. VIEW WEST SOUTHWEST OF BUILDING 7 SHOWING MAIN ENTRANCE ...  

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

1. VIEW WEST SOUTHWEST OF BUILDING 7 SHOWING MAIN ENTRANCE TO OFFICES; MANAGEMENT AND FINANCE OFFICES WERE LOCATED HERE; BUILDING 23 IS AT RIGHT OF PHOTOGRAPH - Bryant Electric Company, 1421 State Street, Bridgeport, Fairfield County, CT

217

5. Lighthouse, first floor and stairs, looking south from entrance ...  

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

5. Lighthouse, first floor and stairs, looking south from entrance - Squirrel Point Light Station, Off Highway 127, Steen Road to end of Bald Head Road, .8 mile down footpath, Arrowsic, Sagadahoc County, ME

218

5. BUILDING 0503, INTERIOR WOODEN ARCHES. Looking south from entrance. ...  

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

5. BUILDING 0503, INTERIOR WOODEN ARCHES. Looking south from entrance. - Edwards Air Force Base, South Base Sled Track, Earth Covered Bunker Types, North of Sled Track, Lancaster, Los Angeles County, CA

219

EXTERIOR VIEW, LOOKING EAST, FRONT FACADE AND ENTRANCE TO COMPANY ...  

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

EXTERIOR VIEW, LOOKING EAST, FRONT FACADE AND ENTRANCE TO COMPANY SCHOOL FOR CHILDREN OF BLACK TCI-US STEEL RED ORE MINE WORKERS - Company School for Blacks, 413 Morgan Road, Bessemer, Jefferson County, AL

220

15. ROOMS 48 AND 49, LOOKING SOUTH FROM ENTRANCE TO ...  

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

15. ROOMS 48 AND 49, LOOKING SOUTH FROM ENTRANCE TO ROOM 47. THE OAK CABINETS ARE USED TO STORE ROCK CORE SAMPLES. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

221

2. EAST ELEVATION. IT IS CURRENTLY THE ENTRANCE ELEVATION. THE ...  

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

2. EAST ELEVATION. IT IS CURRENTLY THE ENTRANCE ELEVATION. THE STREET TO THE LEFT IS RANSTEAD STREET, AND THE STREET TO THE RIGHT IS LUDLOW STREET - Philadelphia Bourse, 11-21 South Fifth Street, Philadelphia, Philadelphia County, PA

222

Detail view in caryatid breezeway to show entrance steps; lion ...  

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

Detail view in caryatid breezeway to show entrance steps; lion statues once flanked these steps - National Park Seminary, Aloha House, North of Linden Lane near corner of Beech Drive, Silver Spring, Montgomery County, MD

223

View of bridge, hospital complex in distance from entrance road ...  

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

View of bridge, hospital complex in distance from entrance road looking West North West - New York State Soldiers & Sailors Home, Department of Veterans Affairs Medical Center, 76 Veterans Avenue, Bath, Steuben County, NY

224

North & south wall elevation of the east entrance loggia; ...  

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

North & south wall elevation of the east entrance loggia; detail of pilaster base and capital - National Zoological Park, Elephant House, 3001 Connecticut Avenue NW, Washington, District of Columbia, DC

225

Perspective view looking across park entrance (path flanked by the ...  

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

Perspective view looking across park entrance (path flanked by the two urns) and down 1100 block of West Lanvale Street - Lafayette Square, Bounded by West Lafayette, North Arlington, West Lanvale & North Carrollton streets, Baltimore, Independent City, MD

226

14. Detail of possible entrance on north side of Pentagon ...  

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

14. Detail of possible entrance on north side of Pentagon 2 (note leaning logs at center). View to west. - Pentagon Site, Pentagon 2, West of Barry's Landing off Highway 37, Fort Smith, Big Horn County, MT

227

2. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 ENTRANCE ...  

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

2. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 ENTRANCE DETAIL, SS. PETER & PAUL'S JESUIT CHURCH, DETROIT MICHIGAN - Sts. Peter & Paul's Jesuit Church, East Jefferson Avenue & Saint Antoine Street, Detroit, Wayne County, MI

228

VIEW ON FIRST FLOOR AT SOUTHEAST ENTRANCE, SHOWING MAIN STAIR, ...  

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

VIEW ON FIRST FLOOR AT SOUTHEAST ENTRANCE, SHOWING MAIN STAIR, DOUBLE LOADED CORRIDOR AT CENTER, AND STAIRS LEADING TO SECOND FLOOR, FACING NORTH - Schwartz Bath House, 2201-2207 East First Street, Los Angeles, Los Angeles County, CA

229

VIEW OF TYPICAL SIDE DOOR ENTRANCE OF BUILDING 23, (AT ...  

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

VIEW OF TYPICAL SIDE DOOR ENTRANCE OF BUILDING 23, (AT SOUTHWEST CORNER), FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

230

VIEW OF FRONT SIDE (ENTRANCE) OF BUILDING 23, FROM MIDDLE ...  

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

VIEW OF FRONT SIDE (ENTRANCE) OF BUILDING 23, FROM MIDDLE OF COURTYARD, FACING WEST - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

231

VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST ...  

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

VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST CORNER OF BUILDING 23, FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

232

OBLIQUE VIEW OF FRONT SIDE (ENTRANCE) AND COURTYARD OF BUILDING ...  

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

OBLIQUE VIEW OF FRONT SIDE (ENTRANCE) AND COURTYARD OF BUILDING 23, FACING SOUTHWEST - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

233

CONTROL BUILDING, WEST FRONT SHOWING ENTRANCE Edwards Air Force ...  

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

CONTROL BUILDING, WEST FRONT SHOWING ENTRANCE - Edwards Air Force Base, X-15 Engine Test Complex, Firing Control Building, Rogers Dry Lake, east of runway between North Base & South Base, Boron, Kern County, CA

234

6. MAIN ENTRANCE, LOOKING SOUTH FROM SYCAMORE STREET; CORNER OF ...  

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

6. MAIN ENTRANCE, LOOKING SOUTH FROM SYCAMORE STREET; CORNER OF BUILDING 88 IS VISIBLE AT RIGHT, BUILDING 93 IS AT CENTER, BUILDING 145 AT LEFT - Rath Packing Company, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

235

49. POWDER MAGAZINE, DETAIL OF ENTRANCE FROM ACCESS PASSAGE SHOWING ...  

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

49. POWDER MAGAZINE, DETAIL OF ENTRANCE FROM ACCESS PASSAGE SHOWING BARRED VENTILATION WINDOWS FLANKING DOORWAY, AND GRANITE STONE SURROUND FROM BOTH, LOOKING NORTHEAST TO SOUTHWEST TOWARDS REAR OF MAGAZINE - Fort Monroe, Fortress, Hampton, Hampton, VA

236

Detail of fire alarm boxes located adjacent to the entrance ...  

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

Detail of fire alarm boxes located adjacent to the entrance of the northwest wing - Mare Island Naval Shipyard, Guard House & Barracks, Railroad Avenue near Eighteenth Street, Vallejo, Solano County, CA

237

1. GENERAL VIEW OF ENTRANCE TO BLUE RIDGE TUNNEL (LEFT) ...  

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

1. GENERAL VIEW OF ENTRANCE TO BLUE RIDGE TUNNEL (LEFT) FROM SOUTHEAST. ORIGINAL BLUE RIDGE R.R. (CROZET) TUNNEL IS VISIBLE AT RIGHT. - Chesapeake & Ohio Railroad, Blue Ridge Tunnel, Highway 250 at Rockfish Gap, Afton, Nelson County, VA

238

14. Main entrance to Gwing from Apollo Drive, looking north ...  

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

14. Main entrance to G-wing from Apollo Drive, looking north - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

239

67. View of old, abandoned vehicular bridge near entrance to ...  

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

67. View of old, abandoned vehicular bridge near entrance to Lake Trapps. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

240

42. View near entrance to Dingle Basin, looking southwest. Photo ...  

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

42. View near entrance to Dingle Basin, looking southwest. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

241

A study of driver behavior on freeway entrance ramps  

E-print Network

A STUDY OF DRIVER BEHAVIOR ON FREEWAY ENTRANCE RAMPS A Thesis By FRED HUNTLEY EDWARDS Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August 1961 Major Subject: Civil Engineering A STUDY OF DRIVER BEHAVIOR ON FREEWAY ENTRANCE RAMPS A Thesis By FRED HUNTLEY EDWARDS Approved as to style and content by: Chairman of Committee Head of Department August 1961 TABLE...

Edwards, Fred Huntley

2012-06-07

242

Regional trends for bud burst and flowering of woody plants in Norway as related to climate change.  

PubMed

Data series for bud burst, beginning of flowering and petal fall for 20 species of deciduous trees and conifers at four sites in different regions of southern Norway have been analysed and related to temperature series. On average, the spring phenophases occurred 7 days earlier during the period 1971-2005. The most significant linear trends were observed for the earliest phases. The trends in this period were compared with trends in other periods, the longest one starting in 1927. Those starting in cold decades and ending in 2005 were in most instances statistically significant, whereas hardly any significant trend appeared for series starting in warm decades. This fact showed that the results of trend studies are very sensitive to the choice of starting year. There were significant decadal variations in 40% of the series. The dates of occurrence of the phenophases, varying from the first days of May to the first days of June, correlated with seasonal temperature series, in most cases strongest to mean temperatures for the seasons March-May and April-May. The North Atlantic Oscillation Index (NAOI) for January and February appeared to have some predictive power for the date of occurrence of the recorded phases. The basis for this may be that the oscillations described by the index are of importance for the fulfilment of physiological chilling requirements needed to break bud dormancy. The same genotypes of the trees were grown in region West Norway and in Central Norwegian region; during the period 1965-2005 the trends towards earlier bud burst were more pronounced and steeper at the western site. PMID:18418631

Nordli, Ø; Wielgolaski, F E; Bakken, A K; Hjeltnes, S H; Måge, F; Sivle, A; Skre, O

2008-09-01

243

Germination responses to temperature and water potential in Jatropha curcas seeds: a hydrotime model explains the difference between dormancy expression and dormancy induction at different incubation temperatures  

PubMed Central

Background and Aims Jatropha curcas is a drought-resistant tree whose seeds are a good source of oil that can be used for producing biodiesel. A successful crop establishment depends on a rapid and uniform germination of the seed. In this work we aimed to characterize the responses of J. curcas seeds to temperature and water availability, using thermal time and hydrotime analysis, Methods Thermal and hydrotime analysis was performed on germination data obtained from the incubation of seeds at different temperatures and at different water potentials. Key Results Base and optimum temperatures were 14·4 and 30 °C, respectively. Approximately 20 % of the seed population displayed absolute dormancy and part of it displayed relative dormancy which was progressively expressed in further fractions when incubation temperatures departed from 25 °C. The thermal time model, but not the hydrotime model, failed to describe adequately final germination percentages at temperatures other than 25 °C. The hydrotime constant, ?H, was reduced when the incubation temperature was increased up to 30 °C, the base water potential for 50 % germination,?b(50), was less negative at 20 and 30 °C than at 25 °C, indicating either expression or induction of dormancy. At 20 °C this less negative ?b(50) explained satisfactorily the germination curves obtained at all water potentials, while at 30 °C it had to be corrected towards even less negative values to match observed curves at water potentials below 0. Hence, ?b(50) appeared to have been further displaced to less negative values as exposure to 30 °C was prolonged by osmoticum. These results suggest expression of dormancy at 20 °C and induction of secondary dormancy above 25 °C. This was confirmed by an experiment showing that inhibition of germination imposed by temperatures higher than 30 °C, but not that imposed at 20 °C, is a permanent effect. Conclusions This study revealed (a) the extremely narrow thermal range within which dormancy problems (either through expression or induction of dormancy) may not be encountered; and (b) the high sensitivity displayed by these seeds to water shortage. In addition, this work is the first one in which temperature effects on dormancy expression could be discriminated from those on dormancy induction using a hydrotime analysis. PMID:21917817

Windauer, Liliana B.; Martinez, J.; Rapoport, D.; Wassner, D.; Benech-Arnold, Roberto

2012-01-01

244

Tumor dormancy and cell signaling. II. Antibody as an agonist in inducing dormancy of a B cell lymphoma in SCID mice  

PubMed Central

Tumor dormancy can be induced in a murine B cell lymphoma (BCL1) by immunizing BALB/c mice with the tumor immunoglobulin (Ig) before tumor cell challenge. In this report, we have investigated the immunological and cellular mechanisms underlying the induction of dormancy. BCL1 tumor cells were injected into SCID mice passively immunized with antibody against different epitopes on IgM or IgD with or without idiotype (Id)-immune T lymphocytes. Results indicate that antibody to IgM is sufficient to induce a state of dormancy. Antibodies against other cell surface molecules including IgD and CD44 (Pgp1) had no effect on tumor growth. Id-immune T cells by themselves also had no effect on tumor growth in SCID mice. However, simultaneous transfer of anti-Id and Id-immune T cells enhanced both the induction and duration of the dormant state. In vitro studies indicated that antibody to IgM induced apoptosis within several hours and cell cycle arrest by 24 h. Hyper cross-linking increased apoptosis. The Fc gamma RII receptor played little or no role in the negative signaling. Antibodies that did not negatively signal in vitro did not induce dormancy in vivo. The results suggest that anti-IgM plays a decisive role in inducing tumor dormancy to BCL1 by acting as an agonist of IgM-mediated signal transduction pathways. PMID:7535341

1995-01-01

245

Studies in Wild Oat Seed Dormancy: I. THE ROLE OF ETHYLENE IN DORMANCY BREAKAGE AND GERMINATION OF WILD OAT SEEDS (AVENA FATUA L.).  

PubMed

Seed of Avena fatua were shown to exhibit a characteristic loss of dormancy during dry storage at 25 C, whereas similar seed stored at 5 C maintained dormancy. 2-Chloroethylphosphonic acid was shown to increase germination of partly dormant seed imbibed under certain temperature regimes; a similar effect could not be established for fully dormant or fully nondormant seed. Using gas-liquid chromatography, natural ethylene levels were followed during imbibition of fully dormant and nondormant seed. A large peak in production was observed in the period prior to radicle emergence in the case of the nondormant seed. Measurements of ethylene production taken at 15 C, following periods of after-ripening in moist soil at either 5 or 25 C, indicated that endogenous production was unlikely to be a main cause of dormancy breakage in this species. The possibility that endogenous ethylene could play a role in natural dormancy breakage in aged seeds is discussed. The practical possibilities of 2-chloroethylphosphonic acid as a dormancy breaking agent in a field situation are outlined. PMID:16661675

Adkins, S W; Ross, J D

1981-02-01

246

HIV-1 Assembly, Budding, and Maturation  

PubMed Central

A defining property of retroviruses is their ability to assemble into particles that can leave producer cells and spread infection to susceptible cells and hosts. Virion morphogenesis can be divided into three stages: assembly, wherein the virion is created and essential components are packaged; budding, wherein the virion crosses the plasma membrane and obtains its lipid envelope; and maturation, wherein the virion changes structure and becomes infectious. All of these stages are coordinated by the Gag polyprotein and its proteolytic maturation products, which function as the major structural proteins of the virus. Here, we review our current understanding of the mechanisms of HIV-1 assembly, budding, and maturation, starting with a general overview and then providing detailed descriptions of each of the different stages of virion morphogenesis. PMID:22762019

Sundquist, Wesley I.; Krausslich, Hans-Georg

2012-01-01

247

Modeling Citation Networks Based on Vigorousness and Dormancy  

NASA Astrophysics Data System (ADS)

In citation networks, the activity of papers usually decreases with age and dormant papers may be discovered and become fashionable again. To model this phenomenon, a competition mechanism is suggested which incorporates two factors: vigorousness and dormancy. Based on this idea, a citation network model is proposed, in which a node has two discrete stage: vigorous and dormant. Vigorous nodes can be deactivated and dormant nodes may be activated and become vigorous. The evolution of the network couples addition of new nodes and state transitions of old ones. Both analytical calculation and numerical simulation show that the degree distribution of nodes in generated networks displays a good right-skewed behavior. Particularly, scale-free networks are obtained as the deactivated vertex is target selected and exponential networks are realized for the random-selected case. Moreover, the measurement of four real-world citation networks achieves a good agreement with the stochastic model.

Wang, Xue-Wen; Zhang, Li-Jie; Yang, Guo-Hong; Xu, Xin-Jian

2013-08-01

248

Breaking Cancer Dormancy to Sensitize Dormant Breast Cancer Cells to Cytotoxic Chemotherapy.  

National Technical Information Service (NTIS)

Patients with breast cancer can develop recurrent metastatic disease with latency periods that range from years to decades. This pause can be explained by micrometastatic disseminated tumor cell (DTC) dormancy, a stage in cancer progression in which resid...

D. Tran

2012-01-01

249

RNA-Seq transcriptome analysis of Spirodela dormancy without reproduction  

PubMed Central

Background Higher plants exhibit a remarkable phenotypic plasticity to adapt to adverse environmental changes. The Greater Duckweed Spirodela, as an aquatic plant, presents exceptional tolerance to cold winters through its dormant structure of turions in place of seeds. Abundant starch in turions permits them to sink and escape the freezing surface of waters. Due to their clonal propagation, they are the fastest growing biomass on earth, providing yet an untapped source for industrial applications. Results We used next generation sequencing technology to examine the transcriptome of turion development triggered by exogenous ABA. A total of 208 genes showed more than a 4-fold increase compared with 154 down-regulated genes in developing turions. The analysis of up-regulated differential expressed genes in response to dormancy exposed an enriched interplay among various pathways: signal transduction, seed dehydration, carbohydrate and secondary metabolism, and senescence. On the other side, the genes responsible for rapid growth and biomass accumulation through DNA assembly, protein synthesis and carbon fixation are repressed. Noticeably, three members of late embryogenesis abundant protein family are exclusively expressed during turion formation. High expression level of key genes in starch synthesis are APS1, APL3 and GBSSI, which could artificially be reduced for re-directing carbon flow from photosynthesis to create a higher energy biomass. Conclusions The identification and functional annotation of differentially expressed genes open a major step towards understanding the molecular network underlying vegetative frond dormancy. Moreover, genes have been identified that could be engineered in duckweeds for practical applications easing agricultural production of food crops. PMID:24456086

2014-01-01

250

Genes controlling seed dormancy and pre-harvest sprouting in a rice-wheat-barley comparison  

Microsoft Academic Search

Pre-harvest sprouting results in significant economic loss for the grain industry around the world. Lack of adequate seed dormancy is the major reason for pre-harvest sprouting in the field under wet weather conditions. Although this trait is governed by multiple genes it is also highly heritable. A major QTL controlling both pre-harvest sprouting and seed dormancy has been identified on

Chengdao Li; Peixiang Ni; Michael Francki; Adam Hunter; Yong Zhang; David Schibeci; Heng Li; Allen Tarr; Jun Wang; Mehmet Cakir; Jun Yu; Matthew Bellgard; Reg Lance; Rudi Appels

2004-01-01

251

The effects of cis-trans ABA on embryo germination and seed dormancy in wheat  

Microsoft Academic Search

Pre-harvest sprouting of wheat grain can cause economic losses especially in cultivars with low levels of seed dormancy. The\\u000a aim of this study was to determine genotype differences in embryo sensitivity to germination in response to exogenous (+\\/–)\\u000a cis-trans ABA treatments at different concentrations. Six white and four red seed-colored bread wheat genotypes that differed in dormancy\\u000a were grown in

J. M. Nyachiro; F. R. Clarke; R. M. DePauw; R. E. Knox; K. C. Armstrong

2002-01-01

252

Detection of seed dormancy QTL in multiple mapping populations derived from crosses involving novel barley germplasm  

Microsoft Academic Search

Seed dormancy is one of the most important traits in germination process to control malting and pre-harvest sprouting in barley\\u000a (Hordeum vulgare L.). EST based linkage maps were constructed on seven recombinant inbred (RI) and one doubled haploid (DH) populations derived\\u000a from crosses including eleven cultivated and one wild barley strains showing the wide range of seed dormancy levels. Seed

Kiyosumi Hori; Kazuhiro Sato; Kazuyoshi Takeda

2007-01-01

253

Dormancy patterns, germination ecology, and seed-bank types of twenty temperate fen grassland species  

Microsoft Academic Search

The germination ecology, including primary and secondary dormancy, mortality of seeds, and seed-bank type, of 20 fen grassland\\u000a species from Northern Germany was investigated using a combination of burial and germination experiments. To analyze primary\\u000a dormancy and effects of after-ripening (dry storage for 28 days) on freshly matured seeds, germination was measured at two\\u000a fluctuating temperature regimes (15\\/25°C and 5\\/15°C)

Kai Jensen

2004-01-01

254

Involvement of the ethylene response pathway in dormancy induction in chrysanthemum.  

PubMed

Temperature plays a significant role in the annual cycling between growth and dormancy of the herbaceous perennial chrysanthemum (Chrysanthemum morifolium Ramat.). After exposure to high summer temperatures, cool temperature triggers dormancy. The cessation of flowering and rosette formation by the cessation of elongation are characteristic of dormant plants, and can be stimulated by exogenous ethylene. Thus, the ethylene response pathway may be involved in temperature-induced dormancy of chrysanthemum. Transgenic chrysanthemums expressing a mutated ethylene receptor gene were used to assess this involvement. The transgenic lines showed reduced ethylene sensitivity: ethylene causes leaf yellowing in wild-type chrysanthemums, but leaves remained green in the transgenic lines. Extension growth and flowering of wild-type and transgenic lines varied between temperatures: at 20 degrees C, the transgenic lines showed the same stem elongation and flowering as the wild type; at cooler temperatures, the wild type formed rosettes with an inability to flower and entered dormancy, but some transgenic lines continued to elongate and flower. This supports the involvement of the ethylene response pathway in the temperature-induced dormancy of chrysanthemum. At the highest dosage of ethephon, an ethylene-releasing agent, wild-type plants formed rosettes with an inability to flower and became dormant, but one transgenic line did not. This confirms that dormancy is induced via the ethylene response pathway. PMID:18952907

Sumitomo, Katsuhiko; Narumi, Takako; Satoh, Shigeru; Hisamatsu, Tamotsu

2008-01-01

255

Involvement of the ethylene response pathway in dormancy induction in chrysanthemum  

PubMed Central

Temperature plays a significant role in the annual cycling between growth and dormancy of the herbaceous perennial chrysanthemum (Chrysanthemum morifolium Ramat.). After exposure to high summer temperatures, cool temperature triggers dormancy. The cessation of flowering and rosette formation by the cessation of elongation are characteristic of dormant plants, and can be stimulated by exogenous ethylene. Thus, the ethylene response pathway may be involved in temperature-induced dormancy of chrysanthemum. Transgenic chrysanthemums expressing a mutated ethylene receptor gene were used to assess this involvement. The transgenic lines showed reduced ethylene sensitivity: ethylene causes leaf yellowing in wild-type chrysanthemums, but leaves remained green in the transgenic lines. Extension growth and flowering of wild-type and transgenic lines varied between temperatures: at 20 °C, the transgenic lines showed the same stem elongation and flowering as the wild type; at cooler temperatures, the wild type formed rosettes with an inability to flower and entered dormancy, but some transgenic lines continued to elongate and flower. This supports the involvement of the ethylene response pathway in the temperature-induced dormancy of chrysanthemum. At the highest dosage of ethephon, an ethylene-releasing agent, wild-type plants formed rosettes with an inability to flower and became dormant, but one transgenic line did not. This confirms that dormancy is induced via the ethylene response pathway. PMID:18952907

Sumitomo, Katsuhiko; Satoh, Shigeru; Hisamatsu, Tamotsu

2008-01-01

256

Transcriptional changes induced by the tumor dormancy-associated microRNA-190  

PubMed Central

Tumor dormancy is a highly prevalent stage in cancer progression. We have previously generated and characterized in vivo experimental models of human tumor dormancy in which micro-tumors remain occult until they spontaneously shift into rapid tumor growth. We showed that the dormant micro-tumors undergo a stable microRNA (miRNA) switch during their transition from dormancy to a fast-growing phenotype and reported the identification of a consensus signature of human tumor dormancy-associated miRNAs (DmiRs). miRNA-190 (miR-190) is among the most upregulated DmiRs in all dormant tumors analyzed. Upregulation of miR-190 led to prolonged tumor dormancy in otherwise fast-growing glioblastomas and osteosarcomas. Here we investigate the transcriptional changes induced by miR-190 expression in cancer cells and show similar patterns of miR-190 mediated transcriptional reprogramming in both glioblastoma and osteosarcoma cells. The data suggests that miR-190 mediated effects rely on an extensive network of molecular changes in tumor cells and that miR-190 affects several transcriptional factors, tumor suppressor genes and interferon response pathways. The molecular mechanisms governing tumor dormancy described in this work may provide promising targets for early prevention of cancer and may lead to novel treatments to convert the malignant tumor phenotype into an asymptomatic dormant state. PMID:23863200

Almog, Nava; Briggs, Christine; Beheshti, Afshin; Ma, Lili; Wilkie, Kathleen P.; Rietman, Edward; Hlatky, Lynn

2013-01-01

257

Analysis of natural allelic variation at seed dormancy loci of Arabidopsis thaliana.  

PubMed Central

Arabidopsis accessions differ largely in their seed dormancy behavior. To understand the genetic basis of this intraspecific variation we analyzed two accessions: the laboratory strain Landsberg erecta (Ler) with low dormancy and the strong-dormancy accession Cape Verde Islands (Cvi). We used a quantitative trait loci (QTL) mapping approach to identify loci affecting the after-ripening requirement measured as the number of days of seed dry storage required to reach 50% germination. Thus, seven QTL were identified and named delay of germination (DOG) 1-7. To confirm and characterize these loci, we developed 12 near-isogenic lines carrying single and double Cvi introgression fragments in a Ler genetic background. The analysis of these lines for germination in water confirmed four QTL (DOG1, DOG2, DOG3, and DOG6) as showing large additive effects in Ler background. In addition, it was found that DOG1 and DOG3 genetically interact, the strong dormancy determined by DOG1-Cvi alleles depending on DOG3-Ler alleles. These genotypes were further characterized for seed dormancy/germination behavior in five other test conditions, including seed coat removal, gibberellins, and an abscisic acid biosynthesis inhibitor. The role of the Ler/Cvi allelic variation in affecting dormancy is discussed in the context of current knowledge of Arabidopsis germination. PMID:12807791

Alonso-Blanco, Carlos; Bentsink, Leónie; Hanhart, Corrie J; Blankestijn-de Vries, Hetty; Koornneef, Maarten

2003-01-01

258

ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.  

PubMed Central

Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds. PMID:19487389

Goggin, Danica E.; Steadman, Kathryn J.; Emery, R. J. Neil; Farrow, Scott C.; Benech-Arnold, Roberto L.; Powles, Stephen B.

2009-01-01

259

Are budburst dates, dormancy and cold acclimation in walnut trees (Juglans regia L.) under mainly genotypic or environmental control?  

PubMed

As observed for most stresses, tree frost resistance can be split into two main processes: avoidance and tolerance. Avoidance of freezing is achieved by introducing species only in the climatic context in which the probability of freezing events is very low for the sensitive stages of buds or stems; i.e., when good synchronism exists between the annual cycle and the critical climatic periods. Buds become able to grow only after chilling requirements have been satisfied (endodormancy released) during winter; they subsequently break after heat requirements have been completed (end of ecodormancy) in early spring. Actually, this period is often subject to more or less severe freezing events. Trees are also able to adjust their freezing tolerance by increasing their capacity of extracellular freezing and decreasing the possibility of intracellular freezing through the process of frost acclimation. Both freezing resistance processes (avoidance and tolerance) are environmentally driven (by photoperiod and temperature), but there are also genotypic effects among species or cultivars. Here, we evaluated the degree to which differences in dormancy release and frost acclimation were related to environmental and genetic influences by comparing trees growing in common garden conditions. This investigation was carried out for two winters in lowland and mountain locations on different walnut genotypes differing significantly for budburst dates. Chilling requirement for endodormancy release and heat requirement during ecodormancy were evaluated in all situations. In addition, frost acclimation was assessed by the electrolyte leakage method on stems from the same trees before leaf fall through budburst. No significant differences were observed in chilling requirements among genotypes. Moreover, frost acclimation dynamics were similar between genotypes or locations when expressed depending on chilling units accumulated since 15 September as a time basis instead of Julian day. The only exception was for maximal frost hardiness observed during winter with the timber-oriented being significantly more resistant than fruit-oriented genotypes. Heat requirement was significantly different among genotypes. Thus, growth was significantly faster in fruit-oriented than in wood-oriented genotypes. Furthermore, among wood-oriented genotypes, differences in growth rate were observed only at cold temperatures. Frost acclimation changes differed significantly between fruit- and wood- walnuts from January through budburst. In conclusion, from September through January, the acclimation dynamic was driven mainly by environmental factors whereas from January through budburst a significant genotype effect was identified in both frost tolerance and avoidance processes. PMID:21805380

Charrier, Guillaume; Bonhomme, Marc; Lacointe, André; Améglio, Thierry

2011-11-01

260

Progressive activation of paratrigeminal nucleus during entrance to hibernation  

SciTech Connect

The paratrigeminal nucleus (Pa5) undergoes a progressive increase in its uptake of 2-({sup 14}C)deoxyglucose (2DG) relative to other brain structures during entrance to hibernation in the ground squirrel. This highly significant increase results in the Pa5 becoming the most highly labeled brain region during hibernation, even though it exhibits one of the lowest levels of 2DG uptake in the brain during the nonhibernating state. The progressive activation of the Pa5 observed during entrance is reversed during arousal from hibernation. These observations and the neuroanatomical projections of the Pa5 implicate this nucleus as playing a role in the entrance and maintenance of the hibernating state.

Kilduff, T.S.; Sharp, F.R.; Heller, H.C. (Stanford Univ., CA (USA) Univ. of California, San Francisco (USA) Veterans Administration Medical Center, San Francisco, CA (USA))

1988-07-01

261

Overexpression of Constans Homologs CO1 and CO2 Fails to Alter Normal Reproductive Onset and Fall Bud Set in Woody Perennial Poplar  

PubMed Central

CONSTANS (CO) is an important flowering-time gene in the photoperiodic flowering pathway of annual Arabidopsis thaliana in which overexpression of CO induces early flowering, whereas mutations in CO cause delayed flowering. The closest homologs of CO in woody perennial poplar (Populus spp.) are CO1 and CO2. A previous report [1] showed that the CO2/FLOWERING LOCUS T1 (FT1) regulon controls the onset of reproduction in poplar, similar to what is seen with the CO/FLOWERING LOCUS T (FT) regulon in Arabidopsis. The CO2/FT1 regulon was also reported to control fall bud set. Our long-term field observations show that overexpression of CO1 and CO2 individually or together did not alter normal reproductive onset, spring bud break, or fall dormancy in poplar, but did result in smaller trees when compared with controls. Transcripts of CO1 and CO2 were normally most abundant in the growing season and rhythmic within a day, peaking at dawn. Our manipulative experiments did not provide evidence for transcriptional regulation being affected by photoperiod, light intensity, temperature, or water stress when transcripts of CO1 and CO2 were consistently measured in the morning. A genetic network analysis using overexpressing trees, microarrays, and computation demonstrated that a majority of functionally known genes downstream of CO1 and CO2 are associated with metabolic processes, which could explain their effect on tree size. In conclusion, the function of CO1 and CO2 in poplar does not appear to overlap with that of CO from Arabidopsis, nor do our data support the involvement of CO1 and CO2 in spring bud break or fall bud set. PMID:23029015

Hsu, Chuan-Yu; Adams, Joshua P.; No, Kyoungok; Liang, Haiying; Meilan, Richard; Pechanova, Olga; Barakat, Abdelali; Carlson, John E.; Page, Grier P.; Yuceer, Cetin

2012-01-01

262

Bud and Yvonne, still imageSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

Bud and Yvonne are delighted by Bud's recovery thanks to Gleevec. Diagnosed with chronic myeloid leukemia (CML), Bud noticed an article in the newspaper on Brian Druker's research. Bud and his wife Yvonne contacted Druker in 1996, and Bud was the first patient to receive the drug STI-571 (Gleevec) in clinical trials.

2008-10-06

263

Role of relative humidity, temperature, and water status in dormancy alleviation of sunflower seeds during dry after-ripening  

PubMed Central

The effect of various combinations of temperature and relative humidity on dormancy alleviation of sunflower seeds during dry after-ripening was investigated. The rate of dormancy alleviation depended on both temperature and embryo moisture content (MC). Below an embryo MC of 0.1 g H2O g?1 dw, dormancy release was faster at 15 °C than at higher temperatures. This suggests that dormancy release at low MC was associated with negative activation energy, supported by Arrhenius plots, and low Q10 values. At higher MC, the rate of dormancy alleviation increased with temperature, correlating well with the temperature dependence of biochemical processes. These findings suggests the involvement of two distinct cellular mechanisms in dormancy release; non-enzymatic below 0.1 g H2O g?1 dw and associated with active metabolism above this value. The effects of temperature on seed dormancy release above the threshold MC were analysed using a population-based thermal time approach and a model predicting the rate of dormancy alleviation is provided. Sunflower embryo dormancy release was effective at temperatures above 8 °C (the base temperature for after-ripening, TbAR, was 8.17 °C), and the higher the after-ripening temperature above this threshold value, the higher was the rate of dormancy loss. Thermodynamic analyses of water sorption isotherms revealed that dormancy release was associated with less bound water and increased molecular mobility within the embryonic axes but not the cotyledons. It is proposed that the changes in water binding properties result from oxidative processes and can, in turn, allow metabolic activities. PMID:20978143

Bazin, J.; Batlla, D.; Dussert, S.; El-Maarouf-Bouteau, H.; Bailly, C.

2011-01-01

264

1. Credit PSR. This view captures the main entrance to ...  

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

1. Credit PSR. This view captures the main entrance to the Administration/Shops Building, constructed in 1963, looking north northeast (30°). The plaque at the base of the flagpole commemorates the first firing of a liquid-fueled rocket engine at Test Stand "A" in 1945. - Jet Propulsion Laboratory Edwards Facility, Administration & Shops Building, Edwards Air Force Base, Boron, Kern County, CA

265

Oblique view, looking eastsoutheast, of main gatehouse, main entrance, and ...  

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

Oblique view, looking east-southeast, of main gatehouse, main entrance, and battery storage house. East side of canal wall in foreground - Grand Valley Diversion Dam, Half a mile north of intersection of I-70 & Colorado State Route 65, Cameo, Mesa County, CO

266

5. GENERAL VIEW OF ENTRANCE ROAD SHOWING WALKWAY TO ADMINISTRATIVE ...  

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

5. GENERAL VIEW OF ENTRANCE ROAD SHOWING WALKWAY TO ADMINISTRATIVE SITE, INTERNAL POLICE POST AND MILITARY POLICE POST, LOOKING NORTHNORHTEAST. - Manzanar War Relocation Center, Owens Valley off U.S. Highway 395, 6 miles South of Independence, Independence, Inyo County, CA

267

1. OVERVIEW OF MAIN ENTRANCE TO RESORT WITH STATE HIGHWAY ...  

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

1. OVERVIEW OF MAIN ENTRANCE TO RESORT WITH STATE HIGHWAY 89 IN FOREGROUND; MAIN LODGE IS ON THE FAR LEFT (WEST); CORD CABIN IS BEHIND AND TO THE RIGHT OF PARKED VEHICLES. - Camp Richardson Resort, Cord Cabin, U.S. Highway 89, 3 miles west of State Highway 50 & 89, South Lake Tahoe, El Dorado County, CA

268

RUTGERS UNIVERSITY STUDENT PRE-ENTRANCE IMMUNIZATION RECORD  

E-print Network

: (Consult your personal physician or Rutgers Health Services if you have questions about these immunizationsRUTGERS UNIVERSITY STUDENT PRE-ENTRANCE IMMUNIZATION RECORD To be completed and signed by your in a country with a high prevalence of TB (If past positive TB skin test, do not repeat. Please record the date

269

103. CANAL AT THE ENTRANCE TO THE POMPTON FEEDER NEAR ...  

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

103. CANAL AT THE ENTRANCE TO THE POMPTON FEEDER NEAR MOUNTAIN VIEW, NEW JERSEY. THE POMPTON FEEDER BOATS TO TRAVEL NORTH 4.26 MILES TO TO POMPTON AS WELL AS PROVIDING THE MAIN CANAL WITH WATER FROM GREENWOOD LAKE. A MODIFIED QUEEN POST TRUSS BRIDGE SPANS THE CANAL IN THE FOREGROUND. - Morris Canal, Phillipsburg, Warren County, NJ

270

South entrance, plan, section, & detail. San Bernardino Valley Union ...  

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

South entrance, plan, section, & detail. San Bernardino Valley Union Junior College, Science Building. Detailed drawings of tile work, wrought iron, and art stone, Howard E. Jones, Architect, San Bernardino, California. Sheet 6, job no. 311. Scale 1.2 inch to the foot. February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

271

9. EXTERIOR VIEW OF FRONT ENTRANCE TO BUNKER. CAMERA FACING ...  

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

9. EXTERIOR VIEW OF FRONT ENTRANCE TO BUNKER. CAMERA FACING EAST. TANK COVER AND FRAME TO THE REAR OF VIEW. INEL PHOTO NUMBER 65-6170, TAKEN NOVEMBER 10, 1965. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

272

ENTRANCE TO GOLD AREA SECURITY ROOM IN BASEMENT, LOCATED IN ...  

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

ENTRANCE TO GOLD AREA SECURITY ROOM IN BASEMENT, LOCATED IN BOTTOM OF ORIGINAL WET-BUCKET ELEVATOR SHAFT, ADJACENT TO DIESTER TABLE ROOM. NOTE BOARD WITH INDIVIDUAL TAGS FOR GOLD AREA EMPLOYEES. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

273

56. View of street level entrance to parking garage elevators ...  

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

56. View of street level entrance to parking garage elevators and detail of aluminum and glass connection to brick from east side of 1946/1948 store for homes and parking garage. - Rich's Downtown Department Store, 45 Broad Street, Atlanta, Fulton County, GA

274

4. VIEW LOOKING WEST FROM ELM STREET AT THE ENTRANCE ...  

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

4. VIEW LOOKING WEST FROM ELM STREET AT THE ENTRANCE TO THE ELM CITY PLANT. NOTE TILE ROOF AND COLONIAL REVIVAL DESIGN MOTIFS. THE BOILER STACK IS VISIBLE ON THE LEFT. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

275

3. Interior. Looking from balance room to the front entrance. ...  

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

3. Interior. Looking from balance room to the front entrance. Chemicals related to Edison's experiments on the extraction of latex for rubber from the goldenrod plant. Room is set up based on reconstruction research done in 1972. - Thomas A. Edison Laboratories, Building No. 2, West Orange, Essex County, NJ

276

42. VIEW OF MARISCAL QUICKSILVER MINE ENTRANCE TWENTY YARDS SOUTHWEST ...  

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

42. VIEW OF MARISCAL QUICKSILVER MINE ENTRANCE TWENTY YARDS SOUTHWEST OF MAIN SHAFT LOOKING NORTHWEST. MINE CLOSURE BY PARK SERVICE, 1995. NOTE CONCRETE FOUNDATIONS IN THE CENTER OF IMAGE BEHIND OPENING FOR MAIN-SHAFT HOIST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

277

UW China Hong Kong Entrance Scholarship University of Waterloo ID#  

E-print Network

UW ­ China Hong Kong Entrance Scholarship Name: University of Waterloo ID#: Program Applied of Waterloo who currently lives in or who previously lived in Hong Kong or mainland China. Candidates must also intend to return to Hong Kong or China after graduation. Selection will be based on academic

Le Roy, Robert J.

278

"Dog House" or vestibule at the secondstory entrance located at ...  

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

"Dog House" or vestibule at the second-story entrance located at the intersection of the west Verandah of the south wing and the south Verandah of the rotunda extension. - U. S. Naval Asylum, Biddle Hall, Gray's Ferry Avenue, Philadelphia, Philadelphia County, PA

279

4. FACING NORTHWEST ACROSS BRIDGE SHOWING ENTRANCE TO PARKING AREA ...  

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

4. FACING NORTHWEST ACROSS BRIDGE SHOWING ENTRANCE TO PARKING AREA BETWEEN TAMARACK AND CASCADE CREEK BRIDGES. POST TO LOWER LEFT, 'B2', IS A MARKER FOR A SELF-GUIDED ROAD TOUR TO PARK. - Tamarack Creek Bridge, Spanning Tamarack Creek on New Big Oak Flat Road, Yosemite Village, Mariposa County, CA

280

5. EAST ENTRANCE TO CATWALK LOOKING TOWARDS THE SOUTHWEST CORNER ...  

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

5. EAST ENTRANCE TO CATWALK LOOKING TOWARDS THE SOUTHWEST CORNER OF THE BUILDING. AGENT STORAGE TANKS LOCATED BELOW CATWALK. - Rocky Mountain Arsenal, Tank House, Quadrant 1, approximately 1000 feet South of December Seventh Avenue; 2200 feet East of D Street, Commerce City, Adams County, CO

281

6. EAST ENTRANCE TO CATWALK LOOKING TOWARDS THE NORTHWEST CORNER ...  

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

6. EAST ENTRANCE TO CATWALK LOOKING TOWARDS THE NORTHWEST CORNER OF THE BUILDING. AGENT STORAGE TANKS LOCATED BELOW CATWALK. - Rocky Mountain Arsenal, Tank House, Quadrant 1, approximately 1000 feet South of December Seventh Avenue; 2200 feet East of D Street, Commerce City, Adams County, CO

282

2. EAST FACADE, ENTRANCE TO CATWALK OVER CONCRETE TANK VAULT. ...  

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

2. EAST FACADE, ENTRANCE TO CATWALK OVER CONCRETE TANK VAULT. BUILDING 742 TO RIGHT OF PHOTOGRAPH. - Rocky Mountain Arsenal, Tank House, Quadrant 1, approximately 1000 feet South of December Seventh Avenue; 2200 feet East of D Street, Commerce City, Adams County, CO

283

PRIMARY ENTRANCE INTO THE JENNE FARM, WEST FAÇADE. (The Jenne ...  

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

PRIMARY ENTRANCE INTO THE JENNE FARM, WEST FAÇADE. (The Jenne Barn has board and batten exterior cladding and sits above-grade on a poured concrete foundation. The barn is painted red with white trim. This door is painted green.) - Jenne Farm, Barn, 538 Engle Road, Coupeville, Island County, WA

284

Interior view, front entrance doors; note; double doors have a ...  

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

Interior view, front entrance doors; note; double doors have a box lock, sliding bolt locks into door head and sill as well as modern locks, butt hinges, slightly recessed panels, and five-ligh transom - Fort Hill, Clemson University Campus, Clemson, Pickens County, SC

285

21. VIEW OF THE ENTRANCE TO THE TUNNEL CONNECTING BUILDINGS ...  

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

21. VIEW OF THE ENTRANCE TO THE TUNNEL CONNECTING BUILDINGS 881 AND 883. THE TUNNEL WAS CONSTRUCTED IN 1957 TO TRANSPORT ENRICHED URANIUM COMPONENTS BETWEEN THE BUILDINGS. (1/98) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

286

Exterior oblique view of trash chute, balconies, and unit entrances ...  

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

Exterior oblique view of trash chute, balconies, and unit entrances on west side of Building 10, from courtyard, looking southeast - North Beach Place, 501 Bay Street, 600 Francisco Street, 501 Bay Street, 600 Francisco Street, San Francisco, San Francisco County, CA

287

VIEW OF ENTRANCE SIDE OF HOUSE, TAKEN FROM NEIGHBORING CARPORT ...  

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

VIEW OF ENTRANCE SIDE OF HOUSE, TAKEN FROM NEIGHBORING CARPORT AREA. WITH NEIGHBOR?S TRASH ENCLOSURE IN FOREGROUND. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Types 8 and 11, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

288

DETAIL VIEW, MAIN ENTRANCE GATES, SHOWING A WINGED HOURGLASS MOTIF, ...  

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

DETAIL VIEW, MAIN ENTRANCE GATES, SHOWING A WINGED HOURGLASS MOTIF, WHICH REFERS TO THE QUICK PASSAGE OF TIME AND THE SHORTNESS OF HUMAN LIFE. USE OF THIS MOTIF WAS A CARRYOVER FROM THE MCARTHUR GATES. - Woodlands Cemetery, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

289

34. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" ENTRANCE CORRIDOR LOOKING ...  

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

34. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" ENTRANCE CORRIDOR LOOKING SOUTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

290

42. ELEVATION EAST FACE BLDG. 4, 3, AND ENTRANCE BLDG. ...  

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

42. ELEVATION EAST FACE BLDG. 4, 3, AND ENTRANCE BLDG. 8. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

291

5. PERSPECTIVE VIEW TO THE NORTHWEST SHOWING ENTRANCE TO CREW ...  

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

5. PERSPECTIVE VIEW TO THE NORTHWEST SHOWING ENTRANCE TO CREW SHELTER AND THE TAPERING SHAPE OF THE SOUTHEAST END WALL OF AR-8. - Edwards Air Force Base, South Base, Rammed Earth Aircraft Dispersal Revetments, Western Shore of Rogers Dry Lake, Boron, Kern County, CA

292

School entrance recommendation: a question of age or development?  

Microsoft Academic Search

Fixed cutoff dates regulating school entry create disadvantages for children who are young relative to their classmates. Early and late school enrollment, though, might mitigate these disadvantages. In this paper, we analyze in a first step which factors determine school entry, if entrance screenings allow for early and late enrollment. Second, we study whether children benefit from a delayed school

Julia Horstschräer; Grit Muehler

2012-01-01

293

2. WEST FRONT ENTRANCE, WITH OWNERS MR. & MRS. ISACC ...  

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

2. WEST FRONT ENTRANCE, WITH OWNERS MR. & MRS. ISACC N. HAGAN (WHO CONTRACTED WITH FRANK LLOYD WRIGHT FOR THE DESIGN OF THIS HOUSE) - Isaac N. Hagan House, Kentuck Knob, U.S. Route 40 vicinity (Stewart Township), Chalkhill, Fayette County, PA

294

69. VIEW OF FOREBAY AND RESERVOIR, SHOWING FLUME ENTRANCE TO ...  

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

69. VIEW OF FOREBAY AND RESERVOIR, SHOWING FLUME ENTRANCE TO RESERVOIR ON THE RIGHT OF FOREBAY IN THE BACKGROUND (SHOWN BY THE WHITE X ON THE PHOTOGRAPHS), Print No. 191, December 1903 - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

295

PennAccess: Moore School Building Entrance Information  

E-print Network

) side of Levine Hall, which is interconnected internally with the Moore School. 3. There is a level entrance on the west (Chancellor) side of Levine Hall, which is interconnected internally with the Moore in the southeast corner of Levine Hall. This elevator goes to all floors of Levine Hall. There are level passages

Plotkin, Joshua B.

296

Molecular Mechanism of Arenavirus Assembly and Budding  

PubMed Central

Arenaviruses have a bisegmented negative-strand RNA genome, which encodes four viral proteins: GP and NP by the S segment and L and Z by the L segment. These four viral proteins possess multiple functions in infection, replication and release of progeny viruses from infected cells. The small RING finger protein, Z protein is a matrix protein that plays a central role in viral assembly and budding. Although all arenaviruses encode Z protein, amino acid sequence alignment showed a huge variety among the species, especially at the C-terminus where the L-domain is located. Recent publications have demonstrated the interactions between viral protein and viral protein, and viral protein and host cellular protein, which facilitate transportation and assembly of viral components to sites of virus egress. This review presents a summary of current knowledge regarding arenavirus assembly and budding, in comparison with other enveloped viruses. We also refer to the restriction of arenavirus production by the antiviral cellular factor, Tetherin/BST-2. PMID:23202453

Urata, Shuzo; Yasuda, Jiro

2012-01-01

297

Epoxyeicosanoids stimulate multiorgan metastasis and tumor dormancy escape in mice.  

PubMed

Epoxyeicosatrienoic acids (EETs) are small molecules produced by cytochrome P450 epoxygenases. They are lipid mediators that act as autocrine or paracrine factors to regulate inflammation and vascular tone. As a result, drugs that raise EET levels are in clinical trials for the treatment of hypertension and many other diseases. However, despite their pleiotropic effects on cells, little is known about the role of these epoxyeicosanoids in cancer. Here, using genetic and pharmacological manipulation of endogenous EET levels, we demonstrate that EETs are critical for primary tumor growth and metastasis in a variety of mouse models of cancer. Remarkably, we found that EETs stimulated extensive multiorgan metastasis and escape from tumor dormancy in several tumor models. This systemic metastasis was not caused by excessive primary tumor growth but depended on endothelium-derived EETs at the site of metastasis. Administration of synthetic EETs recapitulated these results, while EET antagonists suppressed tumor growth and metastasis, demonstrating in vivo that pharmacological modulation of EETs can affect cancer growth. Furthermore, inhibitors of soluble epoxide hydrolase (sEH), the enzyme that metabolizes EETs, elevated endogenous EET levels and promoted primary tumor growth and metastasis. Thus, our data indicate a central role for EETs in tumorigenesis, offering a mechanistic link between lipid signaling and cancer and emphasizing the critical importance of considering possible effects of EET-modulating drugs on cancer. PMID:22182838

Panigrahy, Dipak; Edin, Matthew L; Lee, Craig R; Huang, Sui; Bielenberg, Diane R; Butterfield, Catherine E; Barnés, Carmen M; Mammoto, Akiko; Mammoto, Tadanori; Luria, Ayala; Benny, Ofra; Chaponis, Deviney M; Dudley, Andrew C; Greene, Emily R; Vergilio, Jo-Anne; Pietramaggiori, Giorgio; Scherer-Pietramaggiori, Sandra S; Short, Sarah M; Seth, Meetu; Lih, Fred B; Tomer, Kenneth B; Yang, Jun; Schwendener, Reto A; Hammock, Bruce D; Falck, John R; Manthati, Vijaya L; Ingber, Donald E; Kaipainen, Arja; D'Amore, Patricia A; Kieran, Mark W; Zeldin, Darryl C

2012-01-01

298

[Effects of photoperiod on photosynthesis and PSII performance in peach during dormancy induction].  

PubMed

Long-day and short-day photoperiods were set artificially, with natural condition as the control, to examine photosynthetic parameters and chlorophyll fluorescence transient kinetics of 6-year-old 'Chunjie' peach cultivar (Prunus persica cv. Chunjie), and to investigate the effects of photoperiod on photosynthesis of the northern deciduous fruit trees. The tree advanced into the dormancy induction period under the short-day condition, and delayed under the long-day condition. In the dormancy induction period, the leaf net photosynthetic rate (Pn) and stomatal conductance (g(s)) decreased, and the intercellular CO2 concentration (Ci) increased, suggesting that the Pn decreased because of non-stomatal limitation. Maximum quantum yield for primary photochemistry (PhiPo, or Fv/Fm), potential activity (Fv/Fo), probability that a trapped exciton moved an electron into the electron transport chain beyond Q(A)-(Psi(o)) and performance index on absorption basis (Pl(ABS)) decreased in the dormancy induction period, suggesting that the electron transport capacity of photosynthetic electron transport chain was inhibited, possibly due to the damage to downstream electron transport chain (after Q(A)- acceptor) of PS II reaction center. Long-day photoperiod improved Pn in the dormancy induction period, and reduced the range of decline in PI(ABS) and the injured degree of photosystem. Short-day photoperiod deepened and accelerated the damage to photosynthetic apparatus significantly. The induced effect of photoperiod was associated with the dormancy processes. PMID:25345042

Li, Dong-Mei; Tan, Qiu-Ping; Gao, Dong-Sheng; Chen, Xiu-De; Li, Ling

2014-07-01

299

Computational Predictions of Structures of Multichromosomes of Budding Yeast  

E-print Network

Computational Predictions of Structures of Multichromosomes of Budding Yeast (Accepted, Conf Proc of budding yeast nucleus. We successfully generated a large number of model genomes of yeast with appropriate yeast genome realistically. The model developed here provides a general computational framework

Liang, Jie

300

Rhodopseudomonas palustris and Rh. viridis —Photosynthetic budding bacteria  

Microsoft Academic Search

Rhodopseudomonas palustris and Rh. viridis were found to reproduce by budding. The differences between budding reproduction and binary fission were discussed, and it was concluded that there was a lack of evidence to indicate a fundamental difference between the two processes in bacteria. Taxonomic and nomenclatural changes were discussed.

R. Whittenbury; A. G. McLee

1967-01-01

301

Bud Initiation in Excised Roots of Linaria vulgaris  

Microsoft Academic Search

VEGETATIVE reproduction in Linaria vulgaris is effected by the formation of root-buds at the junction of the parent and some of the lateral roots. Up to four buds may be formed in the superficial layers of the lateral root within the cortex of the parent root1 (Fig. 1), though parent and lateral root tissues are often not separately recognizable in

W. A. Charlton

1965-01-01

302

Effects of shading and thidiazuron + oil treatment on dormancy breaking, blooming and fruit set in apricot in a warm-winter climate  

Microsoft Academic Search

Overcoming dormancy represents one of the major limitations to fruit tree production in warm areas. High temperatures during the chilling period have a negative effect on breaking of dormancy. Shading of trees reduces the incidence of radiation and the temperature. Previous works on shading did not take into account the stage of dormancy. The aim of this work was to

J. A. Campoy; D. Ruiz; J. Egea

2010-01-01

303

Ecotype-dependent control of growth, dormancy and freezing tolerance under seasonal changes in Betula pendula Roth  

Microsoft Academic Search

Woody plants in the temperate and boreal zone undergo annual cycle of growth and dormancy under seasonal changes. Growth cessation and dormancy induction in autumn are prerequisites for the development of substantial cold hardiness in winter. During evolution, woody plants have developed different ecotypes that are closely adapted to the local climatic conditions. In this study, we employed distinct photoperiodic

Chunyang Li; Anneli Viherä-Aarnio; Tuula Puhakainen; Olavi Junttila; Pekka Heino; E. Tapio Palva

2003-01-01

304

Demography, reproduction, and dormancy along altitudinal gradients in three intermountain Allium species with contrasting abundance and distribution  

Microsoft Academic Search

Little is known about the variation in demographics, flower number, fruit set, and summer dormancy in Allium species native to the Intermountain West region of the United States. The purpose of this study was to investigate demographic patterns, summer dormancy traits, and variation in reproductive characteristics among habitats. Three populations of each of three species, Allium acuminatum, A. brandegei, and

Nathan C. Phillips; Daniel T. Drost; William A. Varga; Leila M. Shultz

2011-01-01

305

Effect of low temperature on dormancy breaking and growth after planting in lily bulblets regenerated in vitro  

Microsoft Academic Search

Lilies regenerating on scale segments may develop dormancy in vitro depending on the culture conditions. The dormancy is broken by storage for several weeks at a low temperature (5 °C). The effect of the low temperature on sprouting, time of leaf emergence and further bulb growth was studied. Dormant and non-dormant bulblets were regenerated in vitro on bulb scale segments

Merel M. Langens-Gerrits; William B. M. Miller; Anton F. Croes; Geert-Jan de Klerk

2003-01-01

306

Proteome analysis of Norway maple (Acer platanoides L.) seeds dormancy breaking and germination: influence of abscisic and gibberellic acids  

Microsoft Academic Search

BACKGROUND: Seed dormancy is controlled by the physiological or structural properties of a seed and the external conditions. It is induced as part of the genetic program of seed development and maturation. Seeds with deep physiological embryo dormancy can be stimulated to germinate by a variety of treatments including cold stratification. Hormonal imbalance between germination inhibitors (e.g. abscisic acid) and

Tomasz A Paw?owski

2009-01-01

307

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

PubMed Central

Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the “domestication syndrome.” Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy classes exist among plant species. Physical dormancy (often called hardseededness), as found in legumes, involves the development of a water-impermeable seed coat, caused by the presence of phenolics- and suberin-impregnated layers of palisade cells. The dormancy release mechanism primarily involves seed responses to temperature changes in the habitat, resulting in testa permeability to water. The underlying genetic controls in legumes have not been identified yet. However, positive correlation was shown between phenolics content (e.g., pigmentation), the requirement for oxidation and the activity of catechol oxidase in relation to pea seed dormancy, while epicatechin levels showed a significant positive correlation with soybean hardseededness. myeloblastosis family of transcription factors, WD40 proteins and enzymes of the anthocyanin biosynthesis pathway were involved in seed testa color in soybean, pea and Medicago, but were not tested directly in relation to seed dormancy. These phenolic compounds play important roles in defense against pathogens, as well as affecting the nutritional quality of products, and because of their health benefits, they are of industrial and medicinal interest. In this review, we discuss the role of the testa in mediating legume seed germination, with a focus on structural and chemical aspects. PMID:25101104

Smykal, Petr; Vernoud, Vanessa; Blair, Matthew W.; Soukup, Ales; Thompson, Richard D.

2014-01-01

308

Seed Maturation Regulators Are Related to the Control of Seed Dormancy in Wheat (Triticum aestivum L.).  

PubMed

In Arabidopsis, the regulation network of the seed maturation program controls the induction of seed dormancy. Wheat EST sequences showing homology with the master regulators of seed maturation, LEAFY COTYLEDON1 (LEC1), LEC2 and FUSCA3 (FUS3), were searched from databases and designated respectively as TaL1L (LEC1-LIKE), TaL2L (LEC2-LIKE), and TaFUS3. TaL1LA, TaL2LA and TaFUS3 mainly expressed in seeds or embryos, with the expression limited to the early stages of seed development. Results show that tissue-specific and developmental-stage-dependent expressions are similar to those of seed maturation regulators in Arabidopsis. In wheat cultivars, the expression level of TaL1LA is correlated significantly with the germination index (GI) of whole seeds at 40 days after pollination (DAP) (r?=?-0.83**). Expression levels of TaFUS3 and TaL2LA are significantly correlated respectively with GIs at 40 DAP and 50 DAP, except for dormant cultivars. No correlation was found between the expression level of TaVP1, orthologue of ABA INSENSITIVE3 (ABI3), and seed dormancy. DELAY OF GERMINATION1 (DOG1) was identified as a quantitative trait locus (QTL) for the regulation of seed dormancy in Arabidopsis. Its promoter has RY motif, which is a target sequence of LEC2. Significant correlation was found between the expression of TaDOG1 and seed dormancy except for dormant cultivars. These results indicate that TaL1LA, TaL2LA, and TaFUS3 are wheat orthologues of seed maturation regulators. The expressions of these genes affect the level of seed dormancy. Furthermore, the pathways, which involve seed maturation regulators and TaDOG1, are important for regulating seed dormancy in wheat. PMID:25211528

Rikiishi, Kazuhide; Maekawa, Masahiko

2014-01-01

309

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

PubMed

Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the "domestication syndrome." Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy classes exist among plant species. Physical dormancy (often called hardseededness), as found in legumes, involves the development of a water-impermeable seed coat, caused by the presence of phenolics- and suberin-impregnated layers of palisade cells. The dormancy release mechanism primarily involves seed responses to temperature changes in the habitat, resulting in testa permeability to water. The underlying genetic controls in legumes have not been identified yet. However, positive correlation was shown between phenolics content (e.g., pigmentation), the requirement for oxidation and the activity of catechol oxidase in relation to pea seed dormancy, while epicatechin levels showed a significant positive correlation with soybean hardseededness. myeloblastosis family of transcription factors, WD40 proteins and enzymes of the anthocyanin biosynthesis pathway were involved in seed testa color in soybean, pea and Medicago, but were not tested directly in relation to seed dormancy. These phenolic compounds play important roles in defense against pathogens, as well as affecting the nutritional quality of products, and because of their health benefits, they are of industrial and medicinal interest. In this review, we discuss the role of the testa in mediating legume seed germination, with a focus on structural and chemical aspects. PMID:25101104

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

2014-01-01

310

[Research progress in seegrass seed dormancy, germination, and seedling growth and related affecting factors].  

PubMed

Seagrass bed is the main primary producer in coastal areas, having highly ecological and economical values, and being one of the most important shallow-marine ecosystems. This paper reviewed the research progress in the seed dormancy, germination, and seedling growth of seagrass and related affecting factors, summarized the seed dormancy modes and durations and their affecting factors, and discussed the effects of water salinity, temperature, transparency, hormone, dissolved oxygen, and population structure on the seed germination and the seedling survival and growth. Some issues in related researches and several research directions in the future were prospected. PMID:22303688

Zhang, Pei-Dong; Sun, Yan; Niu, Shu-Na; Zhang, Xiu-Mei

2011-11-01

311

33 CFR 334.390 - Atlantic Ocean south of entrance to Chesapeake Bay; firing range.  

Code of Federal Regulations, 2011 CFR

...Waters 3 2011-07-01 2011-07-01 false Atlantic Ocean south of entrance to Chesapeake Bay; firing range...ZONE AND RESTRICTED AREA REGULATIONS § 334.390 Atlantic Ocean south of entrance to Chesapeake Bay; firing...

2011-07-01

312

33 CFR 334.390 - Atlantic Ocean south of entrance to Chesapeake Bay; firing range.  

Code of Federal Regulations, 2013 CFR

...Waters 3 2013-07-01 2013-07-01 false Atlantic Ocean south of entrance to Chesapeake Bay; firing range...ZONE AND RESTRICTED AREA REGULATIONS § 334.390 Atlantic Ocean south of entrance to Chesapeake Bay; firing...

2013-07-01

313

33 CFR 334.390 - Atlantic Ocean south of entrance to Chesapeake Bay; firing range.  

Code of Federal Regulations, 2012 CFR

...Waters 3 2012-07-01 2012-07-01 false Atlantic Ocean south of entrance to Chesapeake Bay; firing range...ZONE AND RESTRICTED AREA REGULATIONS § 334.390 Atlantic Ocean south of entrance to Chesapeake Bay; firing...

2012-07-01

314

33 CFR 334.390 - Atlantic Ocean south of entrance to Chesapeake Bay; firing range.  

Code of Federal Regulations, 2010 CFR

...Waters 3 2010-07-01 2010-07-01 false Atlantic Ocean south of entrance to Chesapeake Bay; firing range...ZONE AND RESTRICTED AREA REGULATIONS § 334.390 Atlantic Ocean south of entrance to Chesapeake Bay; firing...

2010-07-01

315

46 CFR 111.83-5 - Bottom entrance and protected enclosures.  

Code of Federal Regulations, 2010 CFR

...ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Shore Connection Boxes § 111.83-5 Bottom entrance and protected enclosures. Each shore connection box must have a bottom entrance for the shore connection cable. The box must provide...

2010-10-01

316

Comparative study in stingless bees (Meliponini) demonstrates that nest entrance size predicts traffic and defensivity  

E-print Network

Comparative study in stingless bees (Meliponini) demonstrates that nest entrance size predicts could provide stronger evidence. Stingless bees (Meliponini) are an ideal group for making comparisons; stingless bees. Abstract Stingless bees (Meliponini) construct their own species-specific nest entrance

Wenseleers, Tom

317

Alterations of membrane curvature during influenza virus budding.  

PubMed

Influenza A virus belongs to the Orthomyxoviridae family. It is an enveloped virus that contains a segmented and negative-sense RNA genome. Influenza A viruses cause annual epidemics and occasional major pandemics, are a major cause of morbidity and mortality worldwide, and have a significant financial impact on society. Assembly and budding of new viral particles are a complex and multi-step process involving several host and viral factors. Influenza viruses use lipid raft domains in the apical plasma membrane of polarized epithelial cells as sites of budding. Two viral glycoproteins, haemagglutinin and neuraminidase, concentrate in lipid rafts, causing alterations in membrane curvature and initiation of the budding process. Matrix protein 1 (M1), which forms the inner structure of the virion, is then recruited to the site followed by incorporation of the viral ribonucleoproteins and matrix protein 2 (M2). M1 can alter membrane curvature and progress budding, whereas lipid raft-associated M2 stabilizes the site of budding, allowing for proper assembly of the virion. In the later stages of budding, M2 is localized to the neck of the budding virion at the lipid phase boundary, where it causes negative membrane curvature, leading to scission and virion release. PMID:25233426

Martyna, Agnieszka; Rossman, Jeremy

2014-10-01

318

Section AA through main entrance gates & west stairs. San ...  

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

Section AA through main entrance gates & west stairs. San Bernardino Valley Union Junior College, Science Building. Also includes plans and sections of boys' and girls' toilets. Howard E. Jones, Architect, San Bernardino, California. Sheet 5, job no. 311. Scales 1/4 inch to the foot (section AA) and 1/2 inch to the foot (toilet rooms). February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

319

3. OVERALL VIEW FROM WEST From left to right: Entrance ...  

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

3. OVERALL VIEW FROM WEST From left to right: Entrance Sign Blacksmith Shop No. 2 (HAER No. PA-232-B) Power Plant (HAER No. PA-232-I) Blacksmith Shop No. 1 (HAER No. PA-232-A) Paint Stores (HAER No. PA-232-H) Flue Shed (HAER No. PA-232-E) Boiler Shop - Juniata Shops, East side of Chestnut Avenue, South of Sixth Street, Altoona, Blair County, PA

320

9. NORTHEAST FROM SOUTH ENTRANCE ACROSS RECEIVING AREA OF FACTORY ...  

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

9. NORTHEAST FROM SOUTH ENTRANCE ACROSS RECEIVING AREA OF FACTORY PAST THE GLASS-ENCLOSED OFFICE TOWARD SHOP AREA. BESIDE THE VERTICAL POST ROOF SUPPORT IN THE LEFT FOREGROUND IS A SCALE AND DRAFTING TABLE. BESIDE THE OFFICE WALL ON THE RIGHT IS A SMALL SHOP REPAIR BENCH, WHILE ABOVE THE OFFICE WINDOWS ARE BOXES OF COMPANY MANUSCRIPT BUSINESS RECORDS. THE WELDED METAL PIPE RACK IS A MODERN INTRUSION. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

321

2. View from the mansion formal entrance driveway toward the ...  

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

2. View from the mansion formal entrance driveway toward the big meadow at the Billings Farm & Museum. The driveway is flanked by granite gateposts surmounted by wrought iron urn lamps. The view includes a manicured hemlock hedge (Tsuga canadensis) retained by a stone wall at left, and white birch (Betula species) under-planted with ferns at center. - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

322

30 CFR 18.29 - Access openings and covers, including unused lead-entrance holes.  

...Access openings and covers, including unused lead-entrance holes. 18.29 Section...Access openings and covers, including unused lead-entrance holes. (a) Access openings...Holes in enclosures that are provided for lead entrances but which are not in use...

2014-07-01

323

Budding and fruitfulness of seedless grape in the São Francisco River Valley, northeast Brazil  

Microsoft Academic Search

th 2002, and Apr 8 th to 12 th 2002. The bud burst percentage was calculated by the ratio number of pushed buds and the total number of buds. The fertility index was obtained by dividing the total number of bunches by the total number of buds per plant. The results were statistically analyzed by the SAS computer program, and

Patrícia Coelho de S. Leão; Emanuel E. G da Silva

324

DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature-and  

E-print Network

- and gibberellin-dependent control of seed germination Kai Graebera,b , Ada Linkiesb,c , Tina Steinbrechera , Klaus dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-reg- ulated genes encoding cell of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm

Chittka, Lars

325

TBK1 Regulates Prostate Cancer Dormancy through mTOR Inhibition12  

PubMed Central

The mechanisms that regulate hematopoietic stem cell (HSC) dormancy and self-renewal are well established and are largely dependent on signals emanating from the HSC niche. Recently, we found that prostate cancer (PCa) cells target the HSC niche in mouse bone marrow (BM) during metastasis. Little is known, however, as to how the HSC niche may regulate dormancy in cancer cells. In this study, we investigated the effects of TANK binding kinase 1 (TBK1) on PCa dormancy in the BM niche. We found that binding with niche osteoblasts induces the expression of TBK1 in PCa cells PC3 and C4-2B. Interestingly, TBK1 interacts with mammalian target of rapamycin (mTOR) and inhibits its function. Rapamycin, an mTOR inhibitor, induces cell cycle arrest of PCa cells and enhances chemotherapeutic resistance of PCa cells. As a result, the knockdown of TBK1 decreases PCa stem-like cells and drug resistance in vitro and in vivo. Taken together, these results strongly indicate that TBK1 plays an important role in the dormancy and drug resistance of PCa. PMID:24027431

Kim, Jin Koo; Jung, Younghun; Wang, Jingcheng; Joseph, Jeena; Mishra, Anjali; Hill, Elliott E; Krebsbach, Paul H; Pienta, Kenneth J; Shiozawa, Yusuke; Taichman, Russell S

2013-01-01

326

Temperature effects on dormancy levels and germination in temperate forest sedges (Carex)  

Microsoft Academic Search

The effects of stratification temperatures and burial in soil on dormancy levels of Carex pendula L. and C. remota L., two spring-germinating perennials occurring in moist forests, were investigated. Seeds buried for 34 months outdoors, and seeds stratified in the laboratory at temperatures between 3 and 18 °C for periods between 2 and 28 weeks, were tested over a range of

Markus Brändel; Wolfgang Schütz

2005-01-01

327

8. The role of plant growth regulators in dormancy in forest trees  

Microsoft Academic Search

The role of plant growth regulators, i.e. indole-3-acetic acid, abscisic acid, gibberellins, cytokinins, and ethylene, in the initiation, maintenance, and breaking of dormancy in perennial, woody, temperate plants is reviewed. Particular topics discussed include: a) roles of individual compounds and antagonistic or synergistic effects of several growth regulators acting simultaneously; b) problems of compound isolation and identification; and c) hypotheses

Denis P. Lavender; Salim N. Silim

1987-01-01

328

QTL analysis of seed dormancy in Arabidopsis using recombinant inbred lines and MQM mapping  

Microsoft Academic Search

The genetic differences for seed germination between two commonly used Arabidopsis thaliana ecotypes Ler and Col, both showing a low level of seed dormancy, were investigated. The analysis was performed with 98 recombinant inbred lines (RILs) derived from the cross between the two ecotypes, and these lines had previously been analysed for molecular marker composition. The analysis of germination was

Wybe van der Schaar; Carlos Alonso-Blanco; Karen M. Léon-Kloosterziel; Ritsert C. Jansen; Johan W. van Ooijen; Maarten Koornneef

1997-01-01

329

QTL analysis of seed dormancy in Arabidopsis using recombinant inbred lines and MQM mapping  

Microsoft Academic Search

The genetic differences for seed germination between two commonly used Arabidopsis thaliana ecotypes Ler and Col, both showing a low level of seed dormancy, were investigated. The analysis was performed with 98 recombinant inbred lines (RILs) derived from the cross between the two ecotypes, and these lines had previously been analysed for molecular marker composition by Lister and Dean (Norwich,

Wybe van der Schaar; Carlos Alonso-Blanco; Karen M Léon-Kloosterziel; Ritsert C Jansen; Johan W van Ooijen; Maarten Koornneef

1997-01-01

330

Temperature requirements for dormancy break and seed germination vary greatly among 14 wetland Carex species  

Microsoft Academic Search

We evaluated dormancy loss in seeds of 14 Carex species (C. atherodes, C. brevior, C. comosa, C. cristatella, C. cryptolepis, C. granularis, C. hystericina, C. lacustris, C. pellita, C. scoparia, C. stipata, C. stricta, C. utriculata, C. vulpinoidea) under growing season and stratification conditions and determined the temperature requirements for germination. Seeds were germinated for 1 year at a diel

Karin M. Kettenring; Susan M. Galatowitsch

2007-01-01

331

The Mechanisms Involved in Seed Dormancy Alleviation by Hydrogen Cyanide Unravel the Role of Reactive  

E-print Network

The Mechanisms Involved in Seed Dormancy Alleviation by Hydrogen Cyanide Unravel the Role ethylene or hydrogen cyanide (HCN) during imbibition. The aim of this work was to provide a comprehensive after- ripening or by HCN treatment, and the effect of cyanide on gene expression is likely

Leubner, Gerhard

332

One phase of the dormancy developmental pathway is critical for the evolution of insect seasonality  

E-print Network

Evolutionary change in the timing of dormancy enables animals and plants to adapt to changing seasonal in animal seasonality can result from simple developmental and genetic changes. Although characterizing whether) organisms rapidly respond to global climate change, expand their ranges after accidental

Dopman, Erik B.

333

Cell cycle activity and beta-tubulin accumulation during dormancy breaking of Acer platanoides L. seeds  

Microsoft Academic Search

Cell cycle events in embryo axes of Norway maple (Acer platanoides L.) seeds were studied during dormancy breaking by flow cytometric analyses of the nuclear DNA content and by immunodetection of ?-tubulin. Most embryonic nuclei of dry, fully matured seeds were arrested in the G2 phase of the cell cycle. In addition, the lowest content of ?-tubulin was detected in

T. A. Pawlowski; J. H. W. Bergervoet; R. J. Bino; S. P. C. Groot

2004-01-01

334

Polyamines in dormancy breaking of tree seeds Z. Szczotka U. Lewandowska  

E-print Network

in the physiology of dormancy breaking of Acer platanoides and Fraxi- nus excelsior seeds (in the initial stage) has in Szczotka (1984a, b). A. platanoides seeds were soaked before stratification in the following solutions. Results We observed that changes in the level of polyamine in A. platanoides seeds were similar

Paris-Sud XI, Université de

335

Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure  

NASA Astrophysics Data System (ADS)

Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

2014-05-01

336

Dissecting the spatial structure of overlapping transcription in budding yeast  

E-print Network

This thesis presents a computational and algorithmic method for the analysis of high-resolution transcription data in the budding yeast Saccharomyces cerevisiae. We begin by describing a computational system for storing ...

Danford, Timothy W. (Timothy William), 1979-

2010-01-01

337

A robust budding model of Balinese water temple networks  

Microsoft Academic Search

Ethnohistory, genetics and simulation are used to propose a new ‘budding model’ to describe the historical processes by which complex irrigation communities may come into existence. We review two alternative theories, Wittfogel's top-down state-formation theory and common-pool resource management, and suggest that a budding model would better account for existing archaeological and ethnographic descriptions of a well-studied network of irrigation

J. Stephen Lansing; Murray P. Cox; Sean S. Downey; Marco A. Janssen; John W. Schoenfelder

2009-01-01

338

13. Detail of vestibule, or main entrance, showing lamp and ...  

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

13. Detail of vestibule, or main entrance, showing lamp and eastern set of doors. (Sept. 1991) The other sides of these doors are seen from the inside in WA-197-14. The 'ghosts' of ornamental wooden griffins can be seen above the doors. These griffins were stolen shortly after protective plywood doors were removed on Sept. 6, 1991 in preparation for the public auction on Sept. 10. At the time of the theft, the griffins had not yet been photographed. - Fox Theater, Seventh Avenue & Olive Way, Seattle, King County, WA

339

Evaluation of entrance surface air kerma in pediatric chest radiography  

NASA Astrophysics Data System (ADS)

The objective of this study was to evaluate the entrance surface air kerma in pediatric chest radiography. An evaluation of 301 radiographical examinations in anterior-posterior (AP) and posterior-anterior (PA) (166 examinations) and lateral (LAT) (135 examinations) projections was performed. The analyses were performed on patients grouped by age; the groups included ages 0-1 y, 1-5 y, 5-10 y, and 10-15 y. The entrance surface air kerma was determined with DoseCal software (Radiological Protection Center of Saint George's Hospital, London) and thermoluminescent dosimeters. Two different exposure techniques were compared. The doses received by patients who had undergone LAT examinations were 40% higher, on average, those in AP/PA examinations because of the difference in tube voltage. A large high-dose “tail” was observed for children up to 5 y old. An increase in tube potential and corresponding decrease in current lead to a significant dose reduction. The difference between the average dose values for different age ranges was not practically observed, implying that the exposure techniques are still not optimal. Exposure doses received using the higher tube voltage and lower current-time product correspond to the international diagnostic reference levels.

Porto, L.; Lunelli, N.; Paschuk, S.; Oliveira, A.; Ferreira, J. L.; Schelin, H.; Miguel, C.; Denyak, V.; Kmiecik, C.; Tilly, J.; Khoury, H.

2014-11-01

340

Interface Region Imaging Spectrograph (IRIS) entrance aperture design  

NASA Astrophysics Data System (ADS)

The Interface Region Imaging Spectrograph (IRIS) is a complementary follow-on to Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO-AIA) and funded as a member of the NASA SMEX program. This paper presents the thermal design of the IRIS telescope front end, with a focus on the IRIS door and entrance aperture assembly. The challenge of the IRIS entrance aperture, including the door design, was to manage the solar flux, both before and after the door was opened. This is especially a problem with instruments that are permanently pointed directly at the sun. Though there is an array of effective flux-rejecting coatings, they are expensive, hard to apply, harder to measure, delicate, prone to unpredictable performance decay with exposure, and very often a source of contamination. This paper presents a thermal control and protection method based on robust, inexpensive coatings and materials, combined to produce high thermal and structural isolation. The end result is a first line of thermal protection whose performance is easy to predict and well isolated from the instrument it is protecting.

Cheimets, P.; Park, S.; Bergner, H.; Chou, C.; Gates, R.; Honsa, M.; Podgorski, W.; Yanari, C.

2014-07-01

341

Mapping quantitative trait loci controlling seed dormancy and heading date in rice, Oryza sativa L., using backcross inbred lines  

Microsoft Academic Search

To detect quantitative trait loci (QTLs) controlling seed dormancy, 98 BC1F5 lines (backcross inbred lines) derived from a backcross of Nipponbare (japonica)\\/Kasalath (indica)\\/\\/Nipponbare were analyzed genetically. We used 245 RFLP markers to construct a framework linkage map. Five putative QTLs\\u000a affecting seed dormancy were detected on chromosomes 3, 5, 7 (two regions) and 8, respectively. Phenotypic variations explained\\u000a by each

S. Y. Lin; T. Sasaki; M. Yano

1998-01-01

342

Validating a novel allele of viviparous-1 ( Vp-1Bf ) associated with high seed dormancy of Chinese wheat landrace, Wanxianbaimaizi  

Microsoft Academic Search

Pre-harvest sprouting (PHS) can easily lead to yield losses of wheat and downgrading of grain quality in wheat-growing areas\\u000a where long periods of wet weather occur frequently during harvest. As a main component of PHS, seed dormancy is often evaluated\\u000a by germination index (GI). Previous researches have proved allelic variations of Vp-1B to have a close relationship with dormancy of

C. Chang; J. M. Feng; H. Q. Si; B. Yin; H. P. Zhang; C. X. Ma

2010-01-01

343

Are there efferent synapses in fish taste buds?  

PubMed

In fish, nerve fibers of taste buds are organized within the bud's nerve fiber plexus. It is located between the sensory epithelium consisting of light and dark elongated cells and the basal cells. It comprises the basal parts and processes of light and dark cells that intermingle with nerve fibers, which are the dendritic endings of the taste sensory neurons belonging to the cranial nerves VII, IX or X. Most of the synapses at the plexus are afferent; they have synaptic vesicles on the light (or dark) cells side, which is presynaptic. In contrast, the presumed efferent synapses may be rich in synaptic vesicles on the nerve fibers (presynaptic) side, whereas the cells (postsynaptic) side may contain a subsynaptic cistern; a flat compartment of the smooth endoplasmic reticulum. This structure is regarded as a prerequisite of a typical efferent synapse, as occurring in cochlear and vestibular hair cells. In fish taste buds, efferent synapses are rare and were found only in a few species that belong to different taxa. The significance of efferent synapses in fish taste buds is not well understood, because efferent connections between the gustatory nuclei of the medulla with taste buds are not yet proved. PMID:16217620

Reutter, Klaus; Witt, Martin

2004-12-01

344

Induction of endodormancy in crown buds of leafy spurge (Euphorbia esula L.) implicates a role for ethylene and cross-talk between photoperiod and temperature.  

PubMed

Leafy spurge is a model for studying well-defined phases of dormancy in underground adventitious buds (UABs) of herbaceous perennial weeds, which is a primary factor facilitating their escape from conventional control measures. A 12-week ramp down in both temperature (27 ? 10 °C) and photoperiod (16 ? 8 h light) is required to induce a transition from para- to endo-dormancy in UABs of leafy spurge. To evaluate the effects of photoperiod and temperature on molecular networks of UABs during this transition, we compared global transcriptome data-sets obtained from leafy spurge exposed to a ramp down in both temperature and photoperiod (RDtp) versus a ramp down in temperature (RDt) alone. Analysis of data-sets indicated that transcript abundance for genes associated with circadian clock, photoperiodism, flowering, and hormone responses (CCA1, COP1, HY5, MAF3, MAX2) preferentially increased in endodormant UABs. Gene-set enrichment analyses also highlighted metabolic pathways involved in endodormancy induction that were associated with ethylene, auxin, flavonoids, and carbohydrate metabolism; whereas, sub-network enrichment analyses identified hubs (CCA1, CO, FRI, miR172A, EINs, DREBs) of molecular networks associated with carbohydrate metabolism, circadian clock, flowering, and stress and hormone responses. These results helped refine existing models for the transition to endodormancy in UABs of leafy spurge, which strengthened the roles of circadian clock associated genes, DREBs, COP1-HY5, carbohydrate metabolism, and involvement of hormones (ABA, ethylene, and strigolactones). We further examined the effects of ethylene by application of 1-aminocyclopropane-1-carboxylate (ACC) to paradormant plants without a ramp down treatment. New vegetative growth from UABs of ACC-treated plants resulted in a dwarfed phenotype that mimicked the growth response in RDtp-induced endodormant UABs. The results of this study provide new insights into dormancy regulation suggesting a short-photoperiod treatment provides an additive cross-talk effect with temperature signals that may impact ethylene's effect on AP2/ERF family members. PMID:23436173

Do?ramac?, Münevver; Foley, Michael E; Chao, Wun S; Christoffers, Michael J; Anderson, James V

2013-04-01

345

Cross-species approaches to seed dormancy and germination: conservation and biodiversity of ABA-regulated mechanisms and the Brassicaceae DOG1 genes  

Microsoft Academic Search

Seed dormancy is genetically determined with substantial environmental influence mediated, at least in part, by the plant\\u000a hormone abscisic acid (ABA). The ABA-related transcription factor ABI3\\/VP1 (ABA INSENSITIVE3\\/VIVIPAROUS1) is widespread among green plants. Alternative splicing of its transcripts appears to be involved in regulating seed dormancy,\\u000a but the role of ABI3\\/VP1 goes beyond seeds and dormancy. In contrast, DOG1 (DELAY

Kai Graeber; Ada Linkies; Kerstin Müller; Andrea Wunchova; Anita Rott; Gerhard Leubner-Metzger

2010-01-01

346

Microbial dormancy in batch cultures as a function of substrate-dependent mortality.  

PubMed

We present models and computational studies of dormancy in batch cultures to try to understand the relationship between reculturing time and death penalty for low substrate and the relative advantage of fast versus slow reawakening on the part of the bacteria. We find that the advantage goes to the faster waker for shorter reculturing times and lower mortality under low substrate, and moves to the slower waker as reculturing times and death penalty increase. The advantage returns again to the fast waker for very high death penalties. We use an explicit, continuous structure variable to represent dormancy so as to allow for flexibility in substrate usage on the part of dormant cells, and for a more mechanistic representation of the reawakening process. PMID:22004996

Ayati, Bruce P

2012-01-21

347

Regulation of cell cycle regulators by environmental signals during growth-dormancy cycle of trees  

PubMed Central

Climate change such as changing temperature and increasing concentrations of atmospheric CO2, are likely to drive significant modifications in forests. While many studies have demonstrated the responses and adoptions of tree to fluctuations in climatic and environmental conditions, the impact of environmental signals on trees is complex and poorly understood with respect to the molecular biology in context of the seasonal change of environmental signals. This addendum is focused on the impact of environmental signals on growth-dormancy cycle of trees growing in temperate regions, especially the regulation of cell cycle regulators by temperature and photoperiod. In addition, the plant hormone control of growth-dormancy cycle of trees and cell cycle regulators in the cambium is also discussed. PMID:19826221

Li, Wan-Feng; Cui, Ke-Ming

2009-01-01

348

Nitric oxide implication in the control of seed dormancy and germination  

PubMed Central

Germination ability is regulated by a combination of environmental and endogenous signals with both synergistic and antagonistic effects. Nitric oxide (NO) is a potent dormancy-releasing agent in many species, including Arabidopsis, and has been suggested to behave as an endogenous regulator of this physiological blockage. Distinct reports have also highlighted a positive impact of NO on seed germination under sub-optimal conditions. However, its molecular mode of action in the context of seed biology remains poorly documented. This review aims to focus on the implications of this radical in the control of seed dormancy and germination. The consequences of NO chemistry on the investigations on both its signaling and its targets in seeds are discussed. NO-dependent protein post-translational modifications are proposed as a key mechanism underlying NO signaling during early seed germination. PMID:24065970

Arc, Erwann; Galland, Marc; Godin, Beatrice; Cueff, Gwendal; Rajjou, Loic

2013-01-01

349

Abscisic acid and the regulation of embryo dormancy in the genus Acer.  

PubMed

Germination of Acer pseudoplatanus L. and Acer platanoides L. seeds was increased by moist storage of the intact fruits (seed + pericarp) at 5 degrees C, but not at 17 degrees C. In both species, germinative capacity of isolated embryos (seeds with testa removed) was increased by moist storage of fruits at either 5 or 17 degrees C. Thus dormancy loss by intact seeds and excised embryos was not necessarily correlated. Loss of dormancy in isolated embryos was associated with a reduction in free abscisic acid (ABA) content. Embryos from freshly harvested fruits of A. pseudoplatanus had a higher germinative capacity and a lower free ABA content than embryos from freshly harvested fruits of A. platanoides. Morever, germinative capacity increased, and free ABA content decreased, more rapidly with length of fruit storage in A. platanoides embryos than in A. pseudoplatanus embryos. PMID:14972962

Pinfield, N J; Stutchbury, P A; Bazaid, S A; Gwarazimba, V E

1990-03-01

350

Investigation B: Laminar confined coaxial entrance flow with heat generation  

NASA Technical Reports Server (NTRS)

The results of a parametric study on the entrance flow region in a gas core nuclear reactor are presented. The physical system is modeled as laminar confined, coaxial flow with heat generation in the inner fluid. The governing equations include the boundary layer approximations and the assumptions of only radial radiative transport of energy represented as an energy diffusion term. The Von Mises transformation and a zeta transformation are used to transform the equations into nonlinear nonhomogeneous convective-diffusion equations. A unique combination of forward and backward difference equations which yields accurate results at moderate computational times, is used in the numerical method. Results show that the rapidly accelerating, heat generating inner stream actually shrinks in radius as it expands axially.

Bobba, G. K. M.; Weinstein, H.

1975-01-01

351

Use of burrow entrances to indicate densities of Townsend's ground squirrels  

USGS Publications Warehouse

Counts of burrow entrances have been positively correlated with densities of semi-fossorial rodents and used as an index of densities. We evaluated their effectiveness in indexing densities of Townsend's ground squirrels (Spermophilus townsendii) in the Snake River Birds of Prey National Conservation Area (SRBOPNCA), Idaho, by comparing burrow entrance densities to densities of ground squirrels estimated from livetrapping in 2 consecutive years over which squirrel populations declined by >75%. We did not detect a consistent relation between burrow entrance counts and ground squirrel density estimates within or among habitat types. Scatter plots indicated that burrow entrances had little predictive power at intermediate densities. Burrow entrance counts did not reflect the magnitude of a between-year density decline. Repeated counts of entrances late in the squirrels' active season varied in a manner that would be difficult to use for calibration of transects sampled only once during this period. Annual persistence of burrow entrances varied between habitats. Trained observers were inconsistent in assigning active-inactive status to entrances. We recommend that burrow entrance counts not be used as measures or indices of ground squirrel densities in shrubsteppe habitats, and that the method be verified thoroughly before being used in other habitats.

Van Horne, Beatrice; Schooley, R.L.; Knick, Steven T.; Olson, G.S.; Burnham, K.P.

1997-01-01

352

Dormancy release and seed ageing in the endangered species Silene diclinis  

Microsoft Academic Search

The influence of seed testa color, temperature and seed water content on dormancy release and seed viability loss in the endangered,\\u000a endemic species Silene diclinis (Lag.) M. Laínz was evaluated. Dormant heterogeneous seeds (black, red and grey colored) were exposed to three different\\u000a temperatures (5, 20, and 35°C) and two relative humidities (33 and 60%) in order to assay their

Sara Mira; M. Elena González-Benito; Ana M. Ibars; Elena Estrelles

2011-01-01

353

Dormancy break of celery (Apium graveolens L.) seeds by plant derived smoke extract  

Microsoft Academic Search

Seed dormancy of a highly-dormant cultivar of celery (Apium graveolens L.) was broken by combinations of plant-derived smoke extract or N6-benzyladenine (BA) and gibberellins A4\\/7 (GA4\\/7) in the dark at temperatures between 18 and 26°C. A less dormant cultivar which responded to GA4\\/7 alone showed no additional response to smoke extract or BA. Neither smoke extract nor BA affected either

T. H. Thomas; J. Staden

1995-01-01

354

Role of reactive oxygen species in the regulation of Arabidopsis seed dormancy.  

PubMed

Freshly harvested seeds of Arabidopsis thaliana, Columbia (Col) accession were dormant when imbibed at 25°C in the dark. Their dormancy was alleviated by continuous light during imbibition or by 5 weeks of storage at 20°C (after-ripening). We investigated the possible role of reactive oxygen species (ROS) in the regulation of Col seed dormancy. After 24 h of imbibition at 25°C, non-dormant seeds produced more ROS than dormant seeds, and their catalase activity was lower. In situ ROS localization revealed that germination was associated with an accumulation of superoxide and hydrogen peroxide in the radicle. ROS production was temporally and spatially regulated: ROS were first localized within the cytoplasm upon imbibition of non-dormant seeds, then in the nucleus and finally in the cell wall, which suggests that ROS play different roles during germination. Imbibition of dormant and non-dormant seeds in the presence of ROS scavengers or donors, which inhibited or stimulated germination, respectively, confirmed the role of ROS in germination. Freshly harvested seeds of the mutants defective in catalase (cat2-1) and vitamin E (vte1-1) did not display dormancy; however, seeds of the NADPH oxidase mutants (rbohD) were deeply dormant. Expression of a set of genes related to dormancy upon imbibition in the cat2-1 and vet1-1 seeds revealed that their non-dormant phenotype was probably not related to ABA or gibberellin metabolism, but suggested that ROS could trigger germination through gibberellin signaling activation. PMID:21937678

Leymarie, Juliette; Vitkauskaité, Giedré; Hoang, Hai Ha; Gendreau, Emmanuel; Chazoule, Virginie; Meimoun, Patrice; Corbineau, Françoise; El-Maarouf-Bouteau, Hayat; Bailly, Christophe

2012-01-01

355

Improvement of caper ( Capparis spinosa L.) seed germination by breaking seed coat-induced dormancy  

Microsoft Academic Search

Different dormancy-breaking pretreatments were assessed in order to improve germination of caper (Capparis spinosa L.) seeds. High germination percentages were obtained using concentrated sulfuric acid, followed by either a 90-min soaking procedure in a 100 ppm gibberellin (GA4 + 7) solution, or adding 0.2% potassium nitrate to the test substrate. Results obtained by means of a surgical treatment clearly suggest

Gabriel O. Sozzi; Angel Chiesa

1995-01-01

356

Reduction in Surface Urokinase Receptor Forces Malignant Cells into a Protracted State of Dormancy  

Microsoft Academic Search

Considerable evidence links urokinase plas- minogen activator (uPA) bound to its surface receptor (uPAR) with enhanced invasiveness of cancer cells. By blocking uPAR expression in human epidermoid carci- noma cells (HEp3), we have now identified an addi- tional and novel in vivo function for this receptor by showing that receptor-deficient cells enter a state of dormancy reminiscent of that observed

W. Yu; J. Kim; L. Ossowski

1997-01-01

357

Rate of Change in Dormancy Level and Light Requirement in Weed Seeds During Stratification  

Microsoft Academic Search

The rate of change in dormancy level and light requirement, induced during stratification at 3.2 °C, was investigated in seeds ofStellaria media, Cerastium fontanum, Veronica agrestisandTaraxacum officinale.Two stratification environments, soil and wet filter paper in petri-dishes, were used. On nine occasions during a 6 week stratification period, germination was tested under three light conditions at 3.5\\/18.5 °C: (1) darkness; (2)

ANGELA NORONHA; LARS ANDERSSON; PER MILBERG

1997-01-01

358

Rate of Change in Dormancy Level and Light Requirement in Weed Seeds During Stratification  

Microsoft Academic Search

The rate of change in dormancy level and light requirement, induced during stratification at 3-2 ?C, was investigated in seeds of Stellaria media, Cerastium fontanum, Veronica agrestis and Taraxacum ocinale. Two stratification environments, soil and wet filter paper in petri-dishes, were used. On nine occasions during a 6 week stratification period, germination was tested under three light conditions at 3-5}18-5

ANGELA N ORONHA; L ARS; P ER M ILBERG

359

Dormancy of Nicotiana benthamiana seeds can be broken by different compounds  

Microsoft Academic Search

The influence of after-ripening, sodium nitroprusside, potassium ferricyanide, cyanide, paclobutrazol and nitrite on germination\\u000a of seeds of Nicotiana benthamiana was investigated as well as the influence of plant hormones such as gibberellins and abscisic acid. Dormancy of N. benthamiana seeds was broken by all treatments except treatments with abscisic acid, paclobutrazol and gibberellic acid (GA3). Gibberellins had an interesting effect

Andrea Wünschová; Veronika Be?ová; Helena Vlašínová; Ladislav Havel

2009-01-01

360

Tools for Carex revegetation in freshwater wetlands: understanding dormancy loss and germination temperature requirements  

Microsoft Academic Search

Carex is a globally distributed genus with more than 2000 species worldwide and Carex species are the characteristic vegetation of sedge meadow wetlands. In the mid-continental United States, Carex species are dominant in natural freshwater wetlands yet are slow to recolonize hydrologically restored wetlands. To aid in\\u000a Carex revegetation efforts, we determined the dormancy breaking and temperature germination requirements of

Karin M. Kettenring; Susan M. Galatowitsch

2007-01-01

361

Temperature effects on seed germination and expression of seed dormancy in wheat  

Microsoft Academic Search

Because preharvest sprouting decreases quantity and quality of wheat grain, researchers need effective protocols to assess\\u000a response to preharvest sprouting conditions. The aim of this study was to determine which temperature gives the greatest difference\\u000a in seed germination and expression of seed dormancy in 10 spring wheat genotypes. The genotypes were grown in the field near\\u000a Swift Current, Saskatchewan in

J. M. Nyachiro; F. R. Clarke; R. M. DePauw; R. E. Knox; K. C. Armstrong

2002-01-01

362

Release of sunflower seed dormancy by cyanide: cross-talk with ethylene signalling pathway  

PubMed Central

Freshly harvested sunflower (Helianthus annuus L.) seeds are considered to be dormant because they fail to germinate at relatively low temperatures (10 °C). This dormancy results mainly from an embryo dormancy and disappears during dry storage. Although endogenous ethylene is known to be involved in sunflower seed alleviation of dormancy, little attention had been paid to the possible role of cyanide, which is produced by the conversion of 1-aminocyclopropane 1-carboxylic acid to ethylene, in this process. The aims of this work were to investigate whether exogenous cyanide could improve the germination of dormant sunflower seeds and to elucidate its putative mechanisms of action. Naked dormant seeds became able to germinate at 10 °C when they were incubated in the presence of 1 mM gaseous cyanide. Other respiratory inhibitors showed that this effect did not result from an activation of the pentose phosphate pathway or the cyanide-insensitive pathway. Cyanide stimulated germination of dormant seeds in the presence of inhibitors of ethylene biosynthesis, but its improving effect required functional ethylene receptors. It did not significantly affect ethylene production and the expression of genes involved in ethylene biosynthesis or in the first steps of ethylene signalling pathway. However, the expression of the transcription factor Ethylene Response Factor 1 (ERF1) was markedly stimulated in the presence of gaseous cyanide. It is proposed that the mode of action of cyanide in sunflower seed dormancy alleviation does not involve ethylene production and that ERF1 is a common component of the ethylene and cyanide signalling pathways. PMID:18448476

Oracz, Krystyna; El-Maarouf-Bouteau, Hayat; Bogatek, Renata; Bailly, Christophe

2008-01-01

363

Physical and physiological dormancy in black henbane ( Hyoscyamus niger L.) seeds  

Microsoft Academic Search

Aim of this study was to investigate the nature of dormancy in black henbane (Hyoscyamus niger) seeds which have low germination rate under normal laboratory conditions. To do this, before placing the seeds in Petri\\u000a dishes, they were soaked in 5,10 and 15 mg\\/L GA; 1,2 and 3% H2SO4, 15 mg\\/L GA + 1% H2SO4, 0.01 M KNO3 solutions, tap

Cüneyt çrak; Kudret Kevseroglu; Birsen Sa?lam

2004-01-01

364

GAS EXCHANGE AND VENTILATION DURING DORMANCY IN THE TEGU LIZARD TUPINAMBIS MERIANAE  

Microsoft Academic Search

The tegu lizard Tupinambis merianae exhibits an episodic ventilatory pattern when dormant at 17 °C but a uniform ventilatory pattern when dormant at 25 °C. At 17 °C, ventilatory episodes were composed of 1-22 breaths interspaced by non-ventilatory periods lasting 1.8-26 min. Dormancy at the higher body temperature was accompanied by higher rates of O2 consumption and ventilation. The increase

DENIS VIEIRA DE ANDRADE; AUGUSTO SHINYA ABE

365

Association studies of dormancy and cooking quality traits in direct-seeded indica rice.  

PubMed

Association analysis was applied to a panel of accessions of Assam rice (indica) using 98 SSR markers for dormancy-related traits and cooking quality. Analysis of population structure revealed 10 subgroups in the population. The mean r(2) and D' value for all intrachromosomal loci pairs was 0.24 and 0.51, respectively. Linkage disequilibrium between linked markers decreased with distance. Marker-trait associations were investigated using the unified mixed-model approach, considering both population structure (Q) and kinship (K). Genome-wide scanning, detected a total of seven significant marker-trait associations (P < 0.01), with the R(2) values ranging from 12.0 to 18.0%. The significant marker associations were for grain dormancy (RM27 on chromosome 2), ?-amylase activity (RM27 and RM234 on chromosomes 2 and 7, respectively), germination (RM27 and RM106 on chromosome 2), amylose (RM282 on chromosome 3) and grain length elongation ratio (RM142 on chromosome 4). The present study revealed the association of marker RM27 with traits like dormancy, ?-amylase activity and germination. Simple correlation analysis of these traits revealed that these traits were positively correlated with each other and this marker may be useful for simultaneous improvement of these traits. The study indicates the presence of novel QTLs for a few traits under consideration. The study reveals association of traits like dormancy, ?-amylase activity, germination, amylose content, grain length elongation ratio with SSR markers indicating the feasibility of undertaking association analysis in conjunction with germplasm characterization. PMID:24840818

Rathi, Sunayana; Pathak, K; Yadav, R N S; Kumar, B; Sarma, R N

2014-04-01

366

Cell Cycle Activity and ?-Tubulin Accumulation During Dormancy Breaking of Acer platanoides L. seeds  

Microsoft Academic Search

Cell cycle events in embryo axes of Norway maple (Acer platanoides L.) seeds were studied during dormancy breaking by flow cytometric analyses of the nuclear DNA content and by immunodetection\\u000a of ?-tubulin. Most embryonic nuclei of dry, fully matured seeds were arrested in the G2 phase of the cell cycle. In addition, the lowest content of ?-tubulin was detected in

T. A. Paw?owski; J. H. W. Bergervoet; R. J. Bino; S. P. C. Groot

2004-01-01

367

RoleofEndogenous Growth Regulators inSeedDormancy of Avena fatua  

Microsoft Academic Search

Thehypothesis that endogenous short chain fatty acids (C6-C10)are important inmaintaining seeds ofwild oat(Avena fatua L.)inthedormant state byacting asnatural germination inhibitors (Berrie, Buller, Don, Parker, 1979Plant Physiol 63:758-764) wasinvestigated. Whengermi- nation ofnondormant seeds wasinhibited bytreatment withshort chain fatty acids, theseeds didnotrevert toasimilar biochemical andphysiolog- ical state asexhibited bydormant seeds. First, nonanoic acid-induced inhibition ofseedgermination wasnotreversed byhormone treatments whichnormally break dormancy inwild

I. SHORTCHAINFATTYACIDS

368

Genetic analysis of adaptive syndromes interrelated with seed dormancy in weedy rice ( Oryza sativa )  

Microsoft Academic Search

Seed dormancy in rice interrelates to the weedy characteristics shattering, awn, black hull color, and red pericarp color. A cross between the weedy strain SS18-2 and the breeding line EM93-1 was developed to investigate the genetic basis and adaptive significance of these interrelationships. These characteristics or their components differed in average degree of dominance from -0.8 to 1.5, in heritability

Xing-You Gu; Shahryar F. Kianian; Gary A. Hareland; Barry L. Hoffer; Michael E. Foley

2005-01-01

369

Ruffed grouse feeding behavior and its relationship to secondary metabolites of quaking aspen flower buds.  

PubMed

Quaking aspen (Populus tremuloides Michx.) staminate flower buds and the extended catkins are primary food resources for ruffed grouse (Bonasa umbellus). Winter feeding observations indicate that ruffed grouse select specific trees or clones of quaking aspen to feed in. Flower buds and catkins of quaking aspen were analyzed for secondary compounds (tannins, alkaloids, and phenolics) that might cause ruffed grouse to avoid trees with high levels of these compounds. Coniferyl benzoate, a compound that has not been previously found in quaking aspen, exists in significantly higher concentrations in buds from trees with no feeding history as compared to ruffed grouse feeding trees. Aspen catkins were also significantly lower in coniferyl benzoate than buds from the same tree. Ruffed grouse feeding preference was not related to the tannin or total phenolic levels found in buds or catkins. Buds from feeding trees had higher protein levels than trees with no feeding history; however, catkins did not differ from buds in protein concentration. The high use of extended catkins in the spring by ruffed grouse is probably due to a lower percentage of bud scale material in the catkin as opposed to the dormant bud. Bud scales contain almost all of the nontannin phenolics in catkins and dormant buds. A feeding strategy where bud scales are avoided may exist for other bird species that feed on quaking aspen. Dormant flower buds are significantly lower in protein-precipitable tannins than catkins and differ in secondary metabolite composition from other aspen foliage. PMID:24272191

Jakubas, W J; Gullion, G W; Clausen, T P

1989-06-01

370

Life history, aggregation and dormancy of the rubber plantation litter beetle, Luprops tristis, from the rubber plantations of moist south Western Ghats.  

PubMed

Life history, aggregation and dormancy of rubber plantation litter beetle Luprops tristis Fabricius, (Tenebrionidae: Coleoptera) is described from rubber plantation belts in the western slopes of Western Ghats from the south Indian state of Kerala. The life cycle lasted 12 months, including the 5 larval instars lasting 1 month, the 3 day pupal stage, and the adult stage that can last 11 months. The adult stage includes an inactive dormancy phase of 9 months in shelters and 1 month each of active pre-dormancy (feeding) and post-dormancy (feeding and reproduction) phases that occur in rubber plantation litter. Reproductive activities are confined to the post-dormancy phase. With the onset of summer rains, huge aggregations of adults invade residential buildings and enter into a state of dormancy for 9 months. Beetle aggregations were in the range of 0.5 million to 4.5 million individuals per residential building. Dormancy in L. tristis is best classified as oligopause, which is intermediate between quiescence and diapause. Adults and larvae feed preferentially on wilted rubber tree leaves. Age-specific variation in mortality during dormancy is distinct with higher survivability for adults that have a longer pre-dormancy period. Generations are non-overlapping. PMID:20345315

Sabu, Thomas K; Vinod, K V; Jobi, M C

2008-01-01

371

Selection for low or high primary dormancy in Lolium rigidum Gaud seeds results in constitutive differences in stress protein expression and peroxidase activity  

PubMed Central

Seed dormancy in wild Lolium rigidum Gaud (annual ryegrass) populations is highly variable and not well characterized at the biochemical level. To identify some of the determinants of dormancy level in these seeds, the proteomes of subpopulations selected for low and high levels of primary dormancy were compared by two-dimensional polyacrylamide gel electrophoresis of extracts from mature, dry seeds. High-dormancy seeds showed higher expression of small heat shock proteins, enolase, and glyoxalase I than the low-dormancy seeds. The functional relevance of these differences in protein expression was confirmed by the fact that high-dormancy seeds were more tolerant to high temperatures imposed at imbibition and had consistently higher glyoxalase I activity over 0–42?d dark stratification. Higher expression of a putative glutathione peroxidase in low-dormancy seeds was not accompanied by higher activity, but these seeds had a slightly more oxidized glutathione pool and higher total peroxidase activity. Overall, these biochemical and physiological differences suggest that L. rigidum seeds selected for low dormancy are more prepared for rapid germination via peroxidase-mediated cell wall weakening, whilst seeds selected for high dormancy are constitutively prepared to survive environmental stresses, even in the absence of stress during seed development. PMID:20974739

Goggin, Danica E.; Powles, Stephen B.; Steadman, Kathryn J.

2011-01-01

372

Role of the ectonucleotidase NTPDase2 in taste bud function.  

PubMed

Taste buds are unusual in requiring ATP as a transmitter to activate sensory nerve fibers. In response to taste stimuli, taste cells release ATP, activating purinergic receptors containing the P2X2 and P2X3 subunits on taste nerves. In turn, the released ATP is hydrolyzed to ADP by a plasma membrane nucleoside triphosphate previously identified as nucleoside triphosphate diphosphohydrolase-2 (NTPDase2). In this paper we investigate the role of this ectonucleotidase in the function of taste buds by examining gene-targeted Entpd2-null mice globally lacking NTPDase2. RT-PCR confirmed the absence of NTPDase2, and ATPase enzyme histochemistry reveals no reaction product in taste buds of knockout mice, suggesting that NTPDase2 is the dominant form in taste buds. RT-PCR and immunocytochemistry demonstrated that in knockout mice all cell types are present in taste buds, even those cells normally expressing NTPDase2. In addition, the overall number and size of taste buds are normal in Entpd2-null mice. Luciferin/luciferase assays of circumvallate tissue of knockout mice detected elevated levels of extracellular ATP. Electrophysiological recordings from two taste nerves, the chorda tympani and glossopharyngeal, revealed depressed responses to all taste stimuli in Entpd2-null mice. Responses were more depressed in the glossopharyngeal nerve than in the chorda tympani nerve and involved all taste qualities; responses in the chorda tympani were more depressed to sweet and umami stimuli than to other qualities. We suggest that the excessive levels of extracellular ATP in the Entpd2-knockout animals desensitize the P2X receptors associated with nerve fibers, thereby depressing taste responses. PMID:23959882

Vandenbeuch, Aurelie; Anderson, Catherine B; Parnes, Jason; Enjyoji, Keiichi; Robson, Simon C; Finger, Thomas E; Kinnamon, Sue C

2013-09-01

373

Role of the ectonucleotidase NTPDase2 in taste bud function  

PubMed Central

Taste buds are unusual in requiring ATP as a transmitter to activate sensory nerve fibers. In response to taste stimuli, taste cells release ATP, activating purinergic receptors containing the P2X2 and P2X3 subunits on taste nerves. In turn, the released ATP is hydrolyzed to ADP by a plasma membrane nucleoside triphosphate previously identified as nucleoside triphosphate diphosphohydrolase-2 (NTPDase2). In this paper we investigate the role of this ectonucleotidase in the function of taste buds by examining gene-targeted Entpd2-null mice globally lacking NTPDase2. RT-PCR confirmed the absence of NTPDase2, and ATPase enzyme histochemistry reveals no reaction product in taste buds of knockout mice, suggesting that NTPDase2 is the dominant form in taste buds. RT-PCR and immunocytochemistry demonstrated that in knockout mice all cell types are present in taste buds, even those cells normally expressing NTPDase2. In addition, the overall number and size of taste buds are normal in Entpd2-null mice. Luciferin/luciferase assays of circumvallate tissue of knockout mice detected elevated levels of extracellular ATP. Electrophysiological recordings from two taste nerves, the chorda tympani and glossopharyngeal, revealed depressed responses to all taste stimuli in Entpd2-null mice. Responses were more depressed in the glossopharyngeal nerve than in the chorda tympani nerve and involved all taste qualities; responses in the chorda tympani were more depressed to sweet and umami stimuli than to other qualities. We suggest that the excessive levels of extracellular ATP in the Entpd2-knockout animals desensitize the P2X receptors associated with nerve fibers, thereby depressing taste responses. PMID:23959882

Vandenbeuch, Aurelie; Anderson, Catherine B.; Parnes, Jason; Enjyoji, Keiichi; Robson, Simon C.; Finger, Thomas E.; Kinnamon, Sue C.

2013-01-01

374

Budding of retroviruses utilizing divergent L domains requires nucleocapsid.  

PubMed

We recently reported that human immunodeficiency virus type 1 (HIV-1) carrying PTAP and LYPX(n)L L domains ceased budding when the nucleocapsid (NC) domain was mutated, suggesting a role for NC in HIV-1 release. Here we investigated whether NC involvement in virus release is a property specific to HIV-1 or a general requirement of retroviruses. Specifically, we examined a possible role for NC in the budding of retroviruses relying on divergent L domains and structurally homologous NC domains that harbor diverse protein sequences. We found that NC is critical for the release of viruses utilizing the PTAP motif whether it functions within its native Gag in simian immunodeficiency virus cpzGAB2 (SIVcpzGAB2) or SIVsmmE543 or when it is transplanted into the heterologous Gag protein of equine infectious anemia virus (EIAV). In both cases, virus release was severely diminished even though NC mutant Gag proteins retained the ability to assemble spherical particles. Moreover, budding-defective NC mutants, which displayed particles tethered to the plasma membrane, were triggered to release virus when access to the cell endocytic sorting complex required for transport pathway was restored (i.e., in trans expression of Nedd4.2s). We also examined the role of NC in the budding of EIAV, a retrovirus relying exclusively on the (L)YPX(n)L-type L domain. We found that EIAV late budding defects were rescued by overexpression of the isolated Alix Bro1 domain (Bro1). Bro1-mediated rescue of EIAV release required the wild-type NC. EIAV NC mutants lost interactions with Bro1 and failed to produce viruses despite retaining the ability to self-assemble. Together, our studies establish a role for NC in the budding of retroviruses harboring divergent L domains and evolutionarily diverse NC sequences, suggesting the utilization of a common conserved mechanism and/or cellular factor rather than a specific motif. PMID:22345468

Bello, Nana F; Dussupt, Vincent; Sette, Paola; Rudd, Victoria; Nagashima, Kunio; Bibollet-Ruche, Frederic; Chen, Chaoping; Montelaro, Ronald C; Hahn, Beatrice H; Bouamr, Fadila

2012-04-01

375

The first day of clinical trials for Gleevec, Bud and YvonneSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

Interviewee: Bud DNAi Location:Applications>Genes and medicine>drug design>Bud's Story>The first patient The first patient Yvonne, Bud's wife, talks about the first day of the clinical trials in June of 1998

2008-03-26

376

Cold stratification and exogenous nitrates entail similar functional proteome adjustments during Arabidopsis seed dormancy release.  

PubMed

Despite having very similar initial pools of stored mRNAs and proteins in the dry state, mature Arabidopsis seeds can either proceed toward radicle protrusion or stay in a dormant state upon imbibition. Dormancy breaking, a prerequisite to germination completion, can be induced by different treatments though the underlying mechanisms remain elusive. Thus, we investigated the consequence of such treatments on the seed proteome. Two unrelated dormancy-releasing treatments were applied to dormant seeds, namely, cold stratification and exogenous nitrates, in combination with differential proteomic tools to highlight the specificities of the imbibed dormant state. The results reveal that both treatments lead to highly similar proteome adjustments. In the imbibed dormant state, enzymes involved in reserve mobilization are less accumulated and it appears that several energetically costly processes associated to seed germination and preparation for subsequent seedling establishment are repressed. Our data suggest that dormancy maintenance is associated to an abscisic-acid-dependent recapitulation of the late maturation program resulting in a higher potential to cope with environmental stresses. The comparison of the present results with previously published -omic data sets reinforces and extends the assumption that post-transcriptional, translational, and post-translational regulations are determinant for seed germination. PMID:22985405

Arc, Erwann; Chibani, Kamel; Grappin, Philippe; Jullien, Marc; Godin, Béatrice; Cueff, Gwendal; Valot, Benoit; Balliau, Thierry; Job, Dominique; Rajjou, Loïc

2012-11-01

377

Survival and Dormancy of Mycobacterium avium subsp. paratuberculosis in the Environment  

PubMed Central

The survival of Mycobacterium avium subsp. paratuberculosis was studied by culture of fecal material sampled at intervals for up to 117 weeks from soil and grass in pasture plots and boxes. Survival for up to 55 weeks was observed in a dry fully shaded environment, with much shorter survival times in unshaded locations. Moisture and application of lime to soil did not affect survival. UV radiation was an unlikely factor, but infrared wavelengths leading to diurnal temperature flux may be the significant detrimental component that is correlated with lack of shade. The organism survived for up to 24 weeks on grass that germinated through infected fecal material applied to the soil surface in completely shaded boxes and for up to 9 weeks on grass in 70% shade. The observed patterns of recovery in three of four experiments and changes in viable counts were indicative of dormancy, a hitherto unreported property of this taxon. A dps-like genetic element and relA, which are involved in dormancy responses in other mycobacteria, are present in the M. avium subsp. paratuberculosis genome sequence, providing indirect evidence for the existence of physiological mechanisms enabling dormancy. However, survival of M. avium subsp. paratuberculosis in the environment is finite, consistent with its taxonomic description as an obligate parasite of animals. PMID:15128561

Whittington, Richard J.; Marshall, D. Jeff; Nicholls, Paul J.; Marsh, Ian B.; Reddacliff, Leslie A.

2004-01-01

378

Increased ABA sensitivity results in higher seed dormancy in soft white spring wheat cultivar ‘Zak’  

PubMed Central

As a strategy to increase the seed dormancy of soft white wheat, mutants with increased sensitivity to the plant hormone abscisic acid (ABA) were identified in mutagenized grain of soft white spring wheat “Zak”. Lack of seed dormancy is correlated with increased susceptibility to preharvest sprouting in wheat, especially those cultivars with white kernels. ABA induces seed dormancy during embryo maturation and inhibits the germination of mature grain. Three mutant lines called Zak ERA8, Zak ERA19A, and Zak ERA19B (Zak ENHANCED RESPONSE to ABA) were recovered based on failure to germinate on 5 µM ABA. All three mutants resulted in increased ABA sensitivity over a wide range of concentrations such that a phenotype can be detected at very low ABA concentrations. Wheat loses sensitivity to ABA inhibition of germination with extended periods of dry after-ripening. All three mutants recovered required more time to after-ripen sufficiently to germinate in the absence of ABA and to lose sensitivity to 5 µM ABA. However, an increase in ABA sensitivity could be detected after as long as 3 years of after-ripening using high ABA concentrations. The Zak ERA8 line showed the strongest phenotype and segregated as a single semi-dominant mutation. This mutation resulted in no obvious decrease in yield and is a good candidate gene for breeding preharvest sprouting tolerance. PMID:23212773

Schramm, Elizabeth C.; Nelson, Sven K.; Kidwell, Kimberlee K.

2014-01-01

379

Increased ABA sensitivity results in higher seed dormancy in soft white spring wheat cultivar 'Zak'.  

PubMed

As a strategy to increase the seed dormancy of soft white wheat, mutants with increased sensitivity to the plant hormone abscisic acid (ABA) were identified in mutagenized grain of soft white spring wheat "Zak". Lack of seed dormancy is correlated with increased susceptibility to preharvest sprouting in wheat, especially those cultivars with white kernels. ABA induces seed dormancy during embryo maturation and inhibits the germination of mature grain. Three mutant lines called Zak ERA8, Zak ERA19A, and Zak ERA19B (Zak ENHANCED RESPONSE to ABA) were recovered based on failure to germinate on 5 ?M ABA. All three mutants resulted in increased ABA sensitivity over a wide range of concentrations such that a phenotype can be detected at very low ABA concentrations. Wheat loses sensitivity to ABA inhibition of germination with extended periods of dry after-ripening. All three mutants recovered required more time to after-ripen sufficiently to germinate in the absence of ABA and to lose sensitivity to 5 ?M ABA. However, an increase in ABA sensitivity could be detected after as long as 3 years of after-ripening using high ABA concentrations. The Zak ERA8 line showed the strongest phenotype and segregated as a single semi-dominant mutation. This mutation resulted in no obvious decrease in yield and is a good candidate gene for breeding preharvest sprouting tolerance. PMID:23212773

Schramm, Elizabeth C; Nelson, Sven K; Kidwell, Kimberlee K; Steber, Camille M

2013-03-01

380

Breaking seed dormancy in Hippophae salicifolia, a high value medicinal plant.  

PubMed

Seed dormancy is an important limiting factor in exploitation of an economically important species to its fullest. Hippophae salicifolia D. Don (seabuckthorn), a rich source of medicinal metabolites shows both exogenous and endogenous dormancy. Evidently, we recorded a high seed viability (94 %) but poor germination (22 %) of untreated seeds. We applied different pre-sowing seed priming treatments including NaCl (50, 100, 200, 500 mM), KNO3 (0.1, 0.2, 0.3 %), Thiourea (1, 2, 3 %), GA3 (100, 250, 500 mg/L), Sulphuric acid (98 %) and cold (4 °C) and warm water (65 °C) stratifications to explore improvements in its germination percentage, if any. We found KNO3 (0.1 %) and Thiourea (1 %) treatments to be superior to other methods for enhancement of mean seed germination percentage of H. salicifolia. Considering the practical applicability and cost effectiveness, these treatments can be applied to overcome seed dormancy and recommended for mass multiplication through seeds of H. salicifolia. PMID:23573034

Gupta, Sanjay Mohan; Pandey, Pankaj; Grover, Atul; Ahmed, Zakwan

2011-10-01

381

What Prolongs a Butterfly's Life?: Trade-Offs between Dormancy, Fecundity and Body Size  

PubMed Central

In butterflies, life span often increases only at the expense of fecundity. Prolonged life span, on the other hand, provides more opportunities for oviposition. Here, we studied the association between life span and summer dormancy in two closely related species of Palearctic Meadow Brown butterflies, the endemic Maniola nurag and the widespread M. jurtina, from two climatic provenances, a Mediterranean and a Central European site, and tested the relationships between longevity, body size and fecundity. We experimentally induced summer dormancy and hence prolonged the butterflies’ life in order to study the effects of such a prolonged life. We were able to modulate longevity only in Mediterranean females by rearing them under summer photoperiodic conditions (light 16 h : dark 8 h), thereby more than doubling their natural life span, to up to 246 days. Central European individuals kept their natural average live span under all treatments, as did Mediterranean individuals under autumn treatment (light 11: dark 13). Body size only had a significant effect in the smaller species, M. nurag, where it affected the duration of dormancy and lifetime fecundity. In the larger species, M. jurtina, a prolonged adult life span did, surprisingly, not convey any fecundity loss. In M. nurag, which generally deposited fewer eggs, extended life had a fecundity cost. We conclude that Mediterranen M. jurtina butterflies have an extraordinary plasticity in aging which allows them to extend life span in response to adverse environmental conditions and relieve the time limitation on egg-laying while maintaining egg production at equal levels. PMID:25390334

Haeler, Elena; Fiedler, Konrad; Grill, Andrea

2014-01-01

382

Proteomic analysis of embryogenesis and the acquisition of seed dormancy in Norway maple (Acer platanoides L.).  

PubMed

The proteome of zygotic embryos of Acer platanoides L. was analyzed via high-resolution 2D-SDS-PAGE and MS/MS in order to: (1) identify significant physiological processes associated with embryo development; and (2) identify changes in the proteome of the embryo associated with the acquisition of seed dormancy. Seventeen spots were identified as associated with morphogenesis at 10 to 13 weeks after flowering (WAF). Thirty-three spots were associated with maturation of the embryo at 14 to 22 WAF. The greatest changes in protein abundance occurred at 22 WAF, when seeds become fully mature. Overall, the stage of morphogenesis was characterized by changes in the abundance of proteins (tubulins and actin) associated with the growth and development of the embryo. Enzymes related to energy supply were especially elevated, most likely due to the energy demand associated with rapid growth and cell division. The stage of maturation is crucial to the establishment of seed dormancy and is associated with a higher abundance of proteins involved in genetic information processing, energy and carbon metabolism and cellular and antioxidant processes. Results indicated that a glycine-rich RNA-binding protein and proteasome proteins may be directly involved in dormancy acquisition control, and future studies are warranted to verify this association. PMID:24941250

Staszak, Aleksandra Maria; Paw?owski, Tomasz Andrzej

2014-01-01

383

The Storage and Seasoning of Pecan Bud Wood.  

E-print Network

of plant propagation. Columella (4), about 23 A. D., described this method of graftage, "* * * whereby the tree receives the buds themselves, with a little bark, into a part of itself from which the bark is taken away. * * * It is not fit for all sorts... of plant propagation. Columella (4), about 23 A. D., described this method of graftage, "* * * whereby the tree receives the buds themselves, with a little bark, into a part of itself from which the bark is taken away. * * * It is not fit for all sorts...

Brison, Fred R. (Fred Robert)

1933-01-01

384

Project BudBurst: People, Plants, and Climate Change  

NASA Astrophysics Data System (ADS)

Providing opportunities for individuals to contribute to a better understanding of climate change is the hallmark of Project BudBurst (www.budburst.org). This highly successful, national citizen science program, now in its third year, is bringing climate change education outreach to thousands of individuals. Project BudBurst is a national citizen science initiative designed to engage the public in observations of phenological (plant life cycle) events that raise awareness of climate change, and create a cadre of informed citizen scientists. Citizen science programs such as Project BudBurst provide the opportunity for students and interested laypersons to actively participate in scientific research. Such programs are important not only from an educational perspective, but because they also enable scientists to broaden the geographic and temporal scale of their observations. The goals of Project BudBurst are to 1) increase awareness of phenology as an area of scientific study; 2) Increase awareness of the impacts of changing climates on plants; and 3) increase science literacy by engaging participants in the scientific process. From its 2008 launch in February, this on-line educational and data-entry program, engaged participants of all ages and walks of life in recording the timing of the leafing and flowering of wild and cultivated species found across the continent. Thus far, thousands of participants from all 50 states have submitted data. Project BudBurst has been the subject of almost 200 media outlets including NPR, national and regional television broadcasts, and most of the major national and regional newspapers. This presentation will provide an overview of Project BudBurst and will report on the results of the 2009 field campaign and discuss plans to expand Project BudBurst in 2010 including the use of mobile phones applications for data collection and reporting from the field. Project BudBurst co managed by the National Ecological Observatory Network and the Chicago botanic Garden. Financial support has been received from the National Science Foundation, UCLA Center for Embedded network Sensors U.S. Bureau of Land Management, U.S. Geological Survey , National Geographic Education Foundation, U.S. Fish and Wildlife Foundation, and NASA.

Henderson, S.; Ward, D.; Havens, K.; Gardiner, L. S.; Alaback, P.

2010-12-01

385

Characterization of steam volatiles in the essential oil of black currant buds and the antioxidant properties of different bud extracts.  

PubMed

Currently essential oil from black currant ( Ribes nigrum L.) buds is mainly used as a valuable perfumery ingredient. This study reports more comprehensive characterization of dormant buds of various black currant ( Ribes nigrum L.) cultivars which are grown in Northern European countries. Essential oils were isolated from the buds by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), GC-flame ionization detection (GC-FID), and GC--olfactometry (GC-O). The most abundant compounds in black currant bud essential oil were sabinene, delta-3-carene, and terpinolene. The most frequent descriptors of the essential oil components assessed by GC-O were "woody", "terpene", "fruity", "sweet", "citrus", "herbaceous", "pine", "green", "oily", "herbal", and "musty". The residues obtained after hydrodistillation were separated into liquid and solid fractions. The solid fraction was dried and extracted with acetone (AE), while the liquid fraction (water extract) was divided in two parts, one of which was spray-dried (SDWF extracts) and the other freeze-dried (FDWF extract). In addition, a portion of whole frozen buds was extracted with methanol (ME). The radical scavenging capacity (RSC) of black currant bud extracts varied in a wide range; in the DPPH * reaction system FDWF at the applied concentration scavenged 43-79%; SDWF, 54-80%; AE, 16-36%; ME, 42-60% of radicals; while in the ABTS *+ reaction system the RSC was 39-72, 38-53, 1-5, and 30-49%, respectively. The total amount of phenolic compounds expressed in gallic acid equivalents in FDWF varied in the range of 132-192 mg/g; in SDWF, 140-209 mg/g; in AE, 49-107 mg/g; and in ME extracts, 111-180 mg/g. PMID:18412360

Dvaranauskaite, Asta; Venskutonis, Petras R; Raynaud, Christine; Talou, Thierry; Viskelis, Pranas; Dambrauskiene, Edita

2008-05-14

386

Induction of budding on chloronemata and caulonemata of the moss, Physcomitrella patens , using isopentenyladenine  

Microsoft Academic Search

The bud-inducing effect of the cytokinin N6-(?2-isopentenyl)-adenine (i6-Ade) was examined in the moss Physcomitrella patens growing in liquid culture. Under these conditions, buds could be induced on chloronemata as well as on caulonemata. By application of i6-Ade, bud-formation was accelerated in both types of tissue. The number of buds, their size and their site of development were dependent on the

R. Reski; W. O. Abel

1985-01-01

387

Induction of ectopic taste buds by SHH reveals the competency and plasticity of adult lingual epithelium.  

PubMed

Taste buds are assemblies of elongated epithelial cells, which are innervated by gustatory nerves that transmit taste information to the brain stem. Taste cells are continuously renewed throughout life via proliferation of epithelial progenitors, but the molecular regulation of this process remains unknown. During embryogenesis, sonic hedgehog (SHH) negatively regulates taste bud patterning, such that inhibition of SHH causes the formation of more and larger taste bud primordia, including in regions of the tongue normally devoid of taste buds. Here, using a Cre-lox system to drive constitutive expression of SHH, we identify the effects of SHH on the lingual epithelium of adult mice. We show that misexpression of SHH transforms lingual epithelial cell fate, such that daughter cells of lingual epithelial progenitors form cell type-replete, onion-shaped taste buds, rather than non-taste, pseudostratified epithelium. These SHH-induced ectopic taste buds are found in regions of the adult tongue previously thought incapable of generating taste organs. The ectopic buds are composed of all taste cell types, including support cells and detectors of sweet, bitter, umami, salt and sour, and recapitulate the molecular differentiation process of endogenous taste buds. In contrast to the well-established nerve dependence of endogenous taste buds, however, ectopic taste buds form independently of both gustatory and somatosensory innervation. As innervation is required for SHH expression by endogenous taste buds, our data suggest that SHH can replace the need for innervation to drive the entire program of taste bud differentiation. PMID:24993944

Castillo, David; Seidel, Kerstin; Salcedo, Ernesto; Ahn, Christina; de Sauvage, Frederic J; Klein, Ophir D; Barlow, Linda A

2014-08-01

388

Salamander and Mouse How are the positions of the limb buds determined?  

E-print Network

of the limb buds determined? #12;Fig13.6 Important points: 1. Fgf10 expressed throughout lateral mesoderm 2 stabilized in hindlimb bud by Wnt8c #12;Fig. 13.5 Fgf10 expression where limb buds form An extra (ectopic) limb forms where cells expressing Fgf10 were implanted #12;Fgf10+/+ Fgf10+/- Fgf10-/- #12;Fig. 13

389

Rhabdoviruses and the Cellular Ubiquitin-Proteasome System: a Budding Interaction  

Microsoft Academic Search

The matrix (M) proteins of vesicular stomatitis virus (VSV) and rabies virus (RV) play a key role in both assembly and budding of progeny virions. A PPPY motif (PY motif or late-budding domain) is conserved in the M proteins of VSV and RV. These PY motifs are important for virus budding and for mediating interactions with specific cellular proteins containing

RONALD N. HARTY; MELISSA E. BROWN; JAMES P. MCGETTIGAN; GUANGLI WANG; HIMANGI R. JAYAKAR; JON M. HUIBREGTSE; MICHAEL A. WHITT; MATTHIAS J. SCHNELL

2001-01-01

390

Molecular events of apical bud formation in white spruce, Picea glauca.  

PubMed

Bud formation is an adaptive trait that temperate forest trees have acquired to facilitate seasonal synchronization. We have characterized transcriptome-level changes that occur during bud formation of white spruce [Picea glauca (Moench) Voss], a primarily determinate species in which preformed stem units contained within the apical bud constitute most of next season's growth. Microarray analysis identified 4460 differentially expressed sequences in shoot tips during short day-induced bud formation. Cluster analysis revealed distinct temporal patterns of expression, and functional classification of genes in these clusters implied molecular processes that coincide with anatomical changes occurring in the developing bud. Comparing expression profiles in developing buds under long day and short day conditions identified possible photoperiod-responsive genes that may not be essential for bud development. Several genes putatively associated with hormone signalling were identified, and hormone quantification revealed distinct profiles for abscisic acid (ABA), cytokinins, auxin and their metabolites that can be related to morphological changes to the bud. Comparison of gene expression profiles during bud formation in different tissues revealed 108 genes that are differentially expressed only in developing buds and show greater transcript abundance in developing buds than other tissues. These findings provide a temporal roadmap of bud formation in white spruce. PMID:21118421

El Kayal, Walid; Allen, Carmen C G; Ju, Chelsea J-T; Adams, Eri; King-Jones, Susanne; Zaharia, L Irina; Abrams, Suzanne R; Cooke, Janice E K

2011-03-01

391

Flexible life history responses to flower and rosette bud removal in three perennial herbs  

Microsoft Academic Search

Flexible life history responses to flower and rosette bud removal in three perennial herbs Nienke Hartemink, Eelke Jongejans and Hans de Kroon, In a garden experiment we investigated the response to continuous removal of either flower buds or rosette buds in three perennial grassland species (Hypochaeris radicata, Succisa pratensis and Centaurea jacea), which differ in longevity and flowering type. We

Nienke Hartemink; Eelke Jongejans; J. C. J. M. de Kroon

2004-01-01

392

Spermidine and flower-bud differentiation in thin-layer explants of tobacco  

Microsoft Academic Search

Three lines of evidence indicate a connection between high spermidine levels and floral initiation in thin-layer tissue cultures of Wisconsin-38 tobacco (Nicotiana tabacum L.). (1) Spermidine levels are much higher in floral buds than in vegetative buds. (2) Inhibition of spermidine synthesis by cyclohexylamine prevents the rise in spermidine titer, inhibits floral initiation and promotes the formation of vegetative buds

R. Kaur-Sawhney; A. F. Tiburcio; A. W. Galston

1988-01-01

393

Quantitative resistance of Cirsium arvense to root bud infection by Puccinia punctiformis  

Microsoft Academic Search

A method is presented to test clones of Cirsium arvense for resistance to root bud infection by the rust fungus Puccinia punctiformis. Root buds were stained and cleared to detect mycelium of the rust. The fraction of root buds infected was determined and used as a measure of resistance. Clones of C. arvense, collected from three sites, were tested for

J. Frantzen; W. Van Der Zweerde

1994-01-01

394

The ultrastructural aspects of the cytokinin-induced bud formation in Ceratodon purpureus  

Microsoft Academic Search

Summary The fine structure of gametophore buds developing in response to a cytokinin treatment is described and compared with the results of biochemical and physiological investigations. In the early period of growth, the buds followed a regular pattern of development, with the differentiation of a tetrahedral apical cell at the 3-cell stage of the bud. After 6 and 48 hours

Krystyna Idzikowska; Alicja Szweykowska

1978-01-01

395

Shoot preformation in clones of Fraxinus pennsylvanica in relation to site and year of bud formation  

Microsoft Academic Search

Shoot preformation was investigated in buds of four clones of Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern. at two sites in Manitoba in the second (1988) and third (1989) growing seasons after grafting. More preformed primordia were produced in terminal buds in 1989 compared to 1988 at each site. Both terminal and lateral buds at Morden contained significantly more primordia than

W. R. Remphrey; C. G. Davidson

1994-01-01

396

Budding: A new stage in the development of Chytridiopsis typographi (Zygomycetes: Microsporidia)  

Microsoft Academic Search

Chytridiopsis typographiWeiser, 1954, the microsporidian pathogen of the spruce bark beetle, Ips typographus L. (Coleoptera: Scolytidae), has an early developmental period with plurinucleate mother cells, each of which produces a single bud. The globular bud is connected with the mother cell by a collar and the cellular constituents are pushed to the distant end of the bud. Both the mother

Tomas Tonka; Jaroslav Weiser Jr.

2010-01-01

397

The Inside-Out Mechanism of Dicers from Budding Yeasts  

E-print Network

,5 Dinshaw J. Patel,4,* and David P. Bartel1,2,3,* 1Whitehead Institute for Biomedical Research, 9 Cambridge-Kettering Cancer Center, New York, NY 10065, USA 5These authors contributed equally to this work *Correspondence both Dicer and Argonaute homologs. Nonetheless, other budding-yeast species, including Saccharomyces

Bartel, David

398

Nuclear Envelope Fission Is Linked to Cytokinesis in Budding Yeast  

Microsoft Academic Search

We have investigated the relationship between nuclear envelope fission and cytokinesis during mitotic cell division in budding yeast. By carrying out time-lapse and optical sectioning video microscopy analysis of cells that express green fluorescent protein (GFP)-tagged nuclear envelope and actomyosin ring components, we found that nuclear division is temporally coupled to cytokinesis. Light and electron microscopy analysis also showed that

John Lippincott; Rong Li

2000-01-01

399

Clustering, Communication and Environmental Oscillations in Populations of Budding Yeast  

E-print Network

Clustering, Communication and Environmental Oscillations in Populations of Budding Yeast Chris describe how simple models of communication, consistent with known yeast phys- iological mechanisms relevant variables during yeast growth and division have been reported and studied for over 40 years [8, 12

Young, Todd

400

Soluble Sugar Concentrations Associated with Tuber and Winter Bud Sprouting  

Microsoft Academic Search

Many aquatic weeds rely on vegetative structures for surviv- al and propagation, rather than seeds. American pondweed ( Potamogeton nodosus Poiret) winter buds , and hydrilla ( Hydril- la verticillata (L.f.) Royle, monoecious and dioecious types) tubers were allowed to sprout in water in the dark. At two-to- three day intervals individual propagules and dependent shoots were analyzed for soluble

D. F. SPENCER; F. J. RYAN; L. AUNG; G. G. KSANDER

2001-01-01

401

The inheritance of accessory buds in Rubus idaeus L  

Microsoft Academic Search

In the red raspberry cultivar Lloyd George, accessory (secondary) bud formation is controlled by two complementary genesBd\\u000a 1 andBd\\u000a 2, whose expression is markedly influenced by homozygosity, minor genes, and environment.

Elizabeth Keep

1968-01-01

402

Mechanisms of budding of nanoscale particles through lipid bilayers  

E-print Network

We examine the budding of a nanoscale particle through a lipid bilayer using molecular dynamics simulations, free energy calculations, and an elastic theory, with the aim of determining the extent to which equilibrium elasticity theory can describe the factors that control the mechanism and efficiency of budding. The particle is a smooth sphere which experiences attractive interactions to the lipid head groups. Depending on the parameters, we observe four classes of dynamical trajectories: particle adhesion to the membrane, stalled partially wrapped states, budding followed by scission, and membrane rupture. In most regions of parameter space we find that the elastic theory agrees nearly quantitatively with the simulated phase behavior as a function of adhesion strength, membrane bending rigidity, and particle radius. However, at parameter values near the transition between particle adhesion and budding, we observe long-lived partially wrapped states which are not captured by existing elastic theories. These states could constrain the accessible system parameters for those enveloped viruses or drug delivery vehicles which rely on exo- or endocytosis for membrane transport.

Teresa Ruiz-Herrero; Enrique Velasco; Michael F. Hagan

2012-02-21

403

Science Shorts: Project BudBurst--Analyzing Data  

ERIC Educational Resources Information Center

Project BudBurst is a national program intended to get students and other "citizen scientists" to participate in a real study about plants, the environment, and climate change. It also provides an excellent opportunity for students to build data-analysis skills. A collaboration of several agencies and universities, the program began last year and…

Davis, Kimberly J.; Coskie, Tracy L.

2008-01-01

404

Early Replication of Short Telomeres in Budding Yeast  

E-print Network

Early Replication of Short Telomeres in Budding Yeast Alessandro Bianchi1, * and David Shore1 1.bianchi@molbio.unige.ch DOI 10.1016/j.cell.2007.01.041 SUMMARY The maintenance of an appropriate number of telomere repeats by telomerase is essential for proper chromosome protection. The action of telomerase at the telomere terminus

Halazonetis, Thanos

405

Nipped in the Bud: Suppression of the China Democracy Party  

NSDL National Science Digital Library

In September, Human Rights Watch posted five new reports on their Website. Nipped in the Bud: Suppression of the China Democracy Party examines the situation of more than 30 people imprisoned for their role in the China Democracy Party and argues for their immediate release.

406

Chromosome condensation and sister chromatid pairing in budding yeast  

Microsoft Academic Search

We have developed a fluorescent in situ hy- bridization (FISH) method to examine the structure of both natural chromosomes and small artificial chromo- somes during the mitotic cycle of budding yeast. Our results suggest that the pairing of sister chromatids: (a) occurs near the centromere and at multiple places along the chromosome arm as has been observed in other eukaryotic

Vincent Guacci; Eileen Hogan; Douglas Koshland

1994-01-01

407

Detecting and tracking honeybees in 3D at the beehive entrance using stereo vision  

E-print Network

that the cumulative effect of pesticides, even at doses below the detectable threshold, weakens bees and causes-based system for monitoring flying honeybees in three dimensions at the beehive entrance. Tracking bees-based system that is able to detect bees at the beehive entrance and is sufficiently reli- able for tracking

Paris-Sud XI, Université de

408

Age at Preschool Entrance and Noncognitive Skills before School - An Instrumental Variable Approach  

Microsoft Academic Search

We estimate the effect of age at preschool entrance on crucial noncognitive skills in theyear before school starts. Using an instrumental variable approach and exploiting cut-offdates for the time at preschool entrance we find that children entering preschool earlierin life have better noncognitive skills in terms of being more assertive and being moreable to form friendships. Hence, our results offer

Martin Schlotter

2011-01-01

409

EntranceRequirementswww.cam.ac.uk/entrancerequirements/ Detailswww.cam.ac.uk/entrancerequirements/  

E-print Network

143142 EntranceRequirementswww.cam.ac.uk/entrancerequirements/ Detailswww.cam can be found in our Subject Matters leaflet, available online at: www.study.cam.ac.uk/ undergraduate the website for more details (www.study.cam.ac.uk/ undergraduate/apply/ otherroutes.html). Entrance

Travis, Adrian

410

Integration and sharing study on optimization of campus entrance area design  

Microsoft Academic Search

The planning and construction of campus entrance area is an important part of the integrated and harmonious development of campus and urban. Aiming at several problems in current constructing practice such as formalism, the design of Tianjin light industry technical college entrance area starts from the integrated planning of Haihe educational park, following the idea of \\

Wei SU; Jin Zuo

2011-01-01

411

Reform of the College Entrance Examination: Ideology, Principles, and Policy Recommendations  

ERIC Educational Resources Information Center

Reform of the College Entrance Examination is trending toward simultaneous unification and diversification. The objective of reforming the entrance exam is to establish a college enrollment examination system that is primarily based on a unified test, which would assess students' abilities, appraise them on multiple levels, and classify them.…

Liu, Haifeng

2013-01-01

412

INDICATORS OF CONSERVATION VALUE OF AZOREAN CAVES BASED ON ITS BRYOPHYTE FLORA AT THE ENTRANCE  

Microsoft Academic Search

Cave entrances in the Azores are particularly humid habitats. These provide opportunities for the colonization of a diverse assemblage of bryophyte species. Using both published data and new field sampling, we evaluated species diversity and rarity of bryophytes at the entrance of all known Azorean lava tubes and volcanic pits with such flora. Frequent species include the liverworts: Calypogeia arguta,

Rosalina Gabriel; Fernando Pereira; Paulo A. V. Borges; João P. Constância; S. Miguel

413

Project BudBurst: Citizen Science for All Seasons  

NASA Astrophysics Data System (ADS)

Providing opportunities for individuals to contribute to a better understanding of climate change is the hallmark of Project BudBurst (www.budburst.org). This highly successful, national citizen science program, now in its second year, is bringing climate change education outreach to thousands of individuals. Project BudBurst is a national citizen science initiative designed to engage the public in observations of phenological (plant life cycle) events that raise awareness of climate change, and create a cadre of informed citizen scientists. Citizen science programs such as Project BudBurst provide the opportunity for students and interested laypersons to actively participate in scientific research. Such programs are important not only from an educational perspective, but because they also enable scientists to broaden the geographic and temporal scale of their observations. The goals of Project BudBurst are to 1) increase awareness of phenology as an area of scientific study; 2) Increase awareness of the impacts of changing climates on plants; and 3) increase science literacy by engaging participants in the scientific process. From its 2008 launch in February, this on-line educational and data-entry program, engaged participants of all ages and walks of life in recording the timing of the leafing and flowering of wild and cultivated species found across the continent. Thus far, participants from 49 states have submitted data that is being submitted to the USA National Phenology Network (www.usanpn.org) database. Project BudBurst has been the subject of almost 200 media outlets including NPR, national and regional television broadcasts, and most of the major national and regional newspapers. This presentation will provide an overview of Project Budburst and will report on the results of the 2008 field campaign and discuss plans to expand Project BudBurst in 2009. Project BudBurst is a Windows to the Universe Citizen Science program managed by the University Corporation for Atmospheric Research, the Chicago Botanic Garden, University of Montana in collaboration with the USA -National Phenology Network and with financial support from U.S. Bureau of Land Management, U.S. Geological Survey, NEON, and the Fish and Wildlife Foundation.

Meymaris, K.; Henderson, S.; Alaback, P.; Havens, K.

2008-12-01

414

Low temperature dormancy affects the quantity and quality of the female sexual attractiveness pheromone in red-sided garter snakes.  

PubMed

Low temperature dormancy is a necessary requirement of the annual cycle of most nonmigratory, temperate vertebrates. The red-sided garter snake, Thamnophis sirtalis parietalis, overwinters in communal dens during its prolonged winter dormancy (8 mo), and upon emergence, reproductive behavior of both sexes is maximal. Previous work on this species showed that male courtship behavior is maximally induced after simulated low temperature dormancy. The purpose of this study was to determine whether low temperature dormancy affects the pheromone profiles of individual female red-sided garter snakes. We collected females in the fall at den sites in Manitoba, Canada, and extracted pheromones from individuals at three different time points: fall (field), winter (lab), and spring (lab). Total skin lipid and pheromone fraction masses increased from fall to spring, and pheromone profiles were distinctly different in the fall and spring. Pheromone profiles became dominated by the long-chain, unsaturated methyl ketone components of the blend by the time snakes emerged in the spring. Further, the amounts of both saturated and unsaturated components increased from fall to spring, suggesting significant sex pheromone synthesis was induced by low temperature dormancy. PMID:19904571

Parker, M Rockwell; Mason, Robert T

2009-10-01

415

AXR1 Acts after Lateral Bud Formation to Inhibit Lateral Bud Growth in Arabidopsis1  

PubMed Central

The AXR1 gene of Arabidopsis is required for many auxin responses. The highly branched shoot phenotype of mature axr1 mutant plants has been taken as genetic evidence for a role of auxin in the control of shoot branching. We compared the development of lateral shoots in wild-type Columbia and axr1-12 plants. In the wild type, the pattern of lateral shoot development depends on the developmental stage of the plant. During prolonged vegetative growth, axillary shoots arise and develop in a basal-apical sequence. After floral transition, axillary shoots arise rapidly along the primary shoot axis and grow out to form lateral inflorescences in an apical-basal sequence. For both patterns, the axr1 mutation does not affect the timing of axillary meristem formation; however, subsequent lateral shoot development proceeds more rapidly in axr1 plants. The outgrowth of lateral inflorescences from excised cauline nodes of wild-type plants is inhibited by apical auxin. axr1-12 nodes are resistant to this inhibition. These results provide evidence for common control of axillary growth in both patterns, and suggest a role for auxin during the late stages of axillary shoot development following the formation of the axillary bud and several axillary leaf primordia. PMID:10557232

Stirnberg, Petra; Chatfield, Steven P.; Leyser, H.M. Ottoline

1999-01-01

416

Novel spherical hohlraum with cylindrical laser entrance holes and shields  

NASA Astrophysics Data System (ADS)

Our recent works [K. Lan et al., Phys. Plasmas 21, 010704 (2014); K. Lan et al., Phys. Plasmas 21, 052704 (2014)] have shown that the octahedral spherical hohlraums are superior to the cylindrical hohlraums in both higher symmetry during the capsule implosion and lower backscatter without supplementary technology. However, both the coupling efficiency from the drive laser energy to the capsule and the capsule symmetry decrease remarkably when larger laser entrance holes (LEHs) are used. In addition, the laser beams injected at angles > 45° transport close to the hohlraum wall, thus the wall blowoff causes the LEH to close faster and results in strong laser plasma interactions inside the spherical hohlraums. In this letter, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs to alleviate these problems. From our theoretical study, with the LEH shields, the laser coupling efficiency is significantly increased and the capsule symmetry is remarkably improved in the spherical hohlraums. The cylindrical LEHs take advantage of the cylindrical hohlraum near the LEH and mitigate the influence of the blowoff on laser transport inside a spherical hohlraum. The cylindrical LEHs can also be applied to the rugby and elliptical hohlraums.

Lan, Ke; Zheng, Wudi

2014-09-01

417

The time required for dormancy release in Arabidopsis is determined by DELAY OF GERMINATION1 protein levels in freshly harvested seeds.  

PubMed

Seed dormancy controls the start of a plant's life cycle by preventing germination of a viable seed in an unfavorable season. Freshly harvested seeds usually show a high level of dormancy, which is gradually released during dry storage (after-ripening). Abscisic acid (ABA) has been identified as an essential factor for the induction of dormancy, whereas gibberellins (GAs) are required for germination. The molecular mechanisms controlling seed dormancy are not well understood. DELAY OF GERMINATION1 (DOG1) was recently identified as a major regulator of dormancy in Arabidopsis thaliana. Here, we show that the DOG1 protein accumulates during seed maturation and remains stable throughout seed storage and imbibition. The levels of DOG1 protein in freshly harvested seeds highly correlate with dormancy. The DOG1 protein becomes modified during after-ripening, and its levels in stored seeds do not correlate with germination potential. Although ABA levels in dog1 mutants are reduced and GA levels enhanced, we show that DOG1 does not regulate dormancy primarily via changes in hormone levels. We propose that DOG1 protein abundance in freshly harvested seeds acts as a timer for seed dormancy release, which functions largely independent from ABA. PMID:22829147

Nakabayashi, Kazumi; Bartsch, Melanie; Xiang, Yong; Miatton, Emma; Pellengahr, Silke; Yano, Ryoichi; Seo, Mitsunori; Soppe, Wim J J

2012-07-01

418

An excellent source of vegetative buds for use in plant hormone studies on apical dominance.  

PubMed

When studying the role of plant hormones in the control of growth at apical meristems, it is often difficult to obtain needed amounts of physiologically uniform buds. A source and method are described for obtaining sufficient quantities of large, uniform buds and for the treatment of the buds with indoleacetic acid and kinetin. Buds from the root system of Euphorbia esula L. were grown in Petri plates, with agar suspending the short root sections from which they emanate. Plant hormones are applied by their incorporation in the agar. The effect of various concentrations of indoleacetic acid and kinetin on bud growth was examined. PMID:16658506

Budd, T W

1973-07-01

419

Sequence Variation and Expression Analysis of Seed Dormancy- and Germination-Associated ABA- and GA-Related Genes in Rice Cultivars  

PubMed Central

Abscisic acid (ABA) and Gibberellic acid (GA) play key roles in regulating seed dormancy and germination. First, when examining germination of different rice cultivars, we found that their germination timing and dormancy status are rather distinct, coupled with different GA/ABA ratio. Second, we studied genomic sequences of ABA and GA dormancy- and germination-associated genes in rice and discovered single nucleotide polymorphisms and insertions/deletions (Indels) in both coding and regulatory sequences. We aligned all these variations to the genome assemblies of 9311 and PA64s and demonstrated their relevance to seed dormancy both quantitatively and qualitatively based on gene expression data. Third, we surveyed and compared differentially expressed genes in dry seeds between 9311 and PA64s to show that these differentially expressed genes may play roles in seed dormancy and germination. PMID:22629259

Liu, Fei; Zhang, Hangxiao; Wu, Gang; Sun, Jing; Hao, Lili; Ge, Xiaomeng; Yu, Jun; Wang, Weiwei

2011-01-01

420

33 CFR 110.54 - Long Island Sound, on west side of entrance to Pataguanset River, Conn.  

Code of Federal Regulations, 2010 CFR

...Waters 1 2010-07-01 2010-07-01 false Long Island Sound, on west side of entrance to Pataguanset River...REGULATIONS Special Anchorage Areas § 110.54 Long Island Sound, on west side of entrance to Pataguanset...

2010-07-01

421

16 CFR Figures 2 and 3 to Part 1512 - Handlebar Stem Loading and Entrance 8 Observation Angles  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Handlebar Stem Loading and Entrance 8 Observation Angles 2 Figures 2 and 3 to Part 1512 Commercial Practices ...Part 1512—Handlebar Stem Loading and Entrance 8 Observation Angles...

2011-01-01

422

16 CFR Figures 2 and 3 to Part 1512 - Handlebar Stem Loading and Entrance 8 Observation Angles  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Handlebar Stem Loading and Entrance 8 Observation Angles 2 Figures 2 and 3 to Part 1512 Commercial Practices ...Part 1512—Handlebar Stem Loading and Entrance 8 Observation Angles...

2010-01-01

423

33 CFR 165.731 - Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance Channel.  

Code of Federal Regulations, 2010 CFR

...false Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance...731 Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance...and land from bank to bank within Cumberland Sound and the...

2010-07-01

424

33 CFR 165.731 - Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance Channel.  

Code of Federal Regulations, 2011 CFR

...false Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance...731 Safety/Security Zone: Cumberland Sound, Georgia and St. Marys River Entrance...and land from bank to bank within Cumberland Sound and the...

2011-07-01

425

Induction of secondary dormancy by hypoxia in barley grains and its hormonal regulation.  

PubMed

In barley, primary dormant grains did not germinate at 30 °C in air and at 15 °C in an atmosphere containing less than 10% O2, while they germinated easily at 15 °C in air. O2 tension in embryos measured with microsensors was 15.8% at 15 °C but only 0.3% at 30 °C. Incubation of grains at 30 °C is known to induce secondary dormancy in barley, and it was shown here that secondary dormancy was also induced by a 3 d treatment in O2 tensions lower than 10% at 15 °C. After such treatments, the grains lost their ability to germinate subsequently at 15 °C in air. During seed treatment in 5% O2, embryo abscisic acid (ABA) content decreased more slowly than in air and was not altered after transfer into air. Hypoxia did not alter the expression of ABA metabolism genes after 1 d, and induction of HvNCED2 occurred only after 3 d in hypoxia. Embryo sensitivity to ABA was similar in both primary and hypoxia-induced secondary dormant grains. Gibberellic acid (GA) metabolism genes were highly regulated and regulated earlier by the hypoxia treatment, with major changes in HvGA2ox3, HvGA3ox2 and HvGA20ox1 expression after 1 d, resulting in reduced GA signalling. Although a high temperature has an indirect effect on O2 availability, the data showed that it did not affect expression of prolyl-4-hydroxylases and that induction of secondary dormancy by hypoxia at 15 °C or by high temperature in air involved separate signalling pathways. Induction by hypoxia at 15 °C appears to be more regulated by GA and less by ABA than the induction by high temperature. PMID:23519728

Hoang, Hai Ha; Bailly, Christophe; Corbineau, Françoise; Leymarie, Juliette

2013-04-01

426

Induction of secondary dormancy by hypoxia in barley grains and its hormonal regulation  

PubMed Central

In barley, primary dormant grains did not germinate at 30 °C in air and at 15 °C in an atmosphere containing less than 10% O2, while they germinated easily at 15 °C in air. O2 tension in embryos measured with microsensors was 15.8% at 15 °C but only 0.3% at 30 °C. Incubation of grains at 30 °C is known to induce secondary dormancy in barley, and it was shown here that secondary dormancy was also induced by a 3 d treatment in O2 tensions lower than 10% at 15 °C. After such treatments, the grains lost their ability to germinate subsequently at 15 °C in air. During seed treatment in 5% O2, embryo abscisic acid (ABA) content decreased more slowly than in air and was not altered after transfer into air. Hypoxia did not alter the expression of ABA metabolism genes after 1 d, and induction of HvNCED2 occurred only after 3 d in hypoxia. Embryo sensitivity to ABA was similar in both primary and hypoxia-induced secondary dormant grains. Gibberellic acid (GA) metabolism genes were highly regulated and regulated earlier by the hypoxia treatment, with major changes in HvGA2ox3, HvGA3ox2 and HvGA20ox1 expression after 1 d, resulting in reduced GA signalling. Although a high temperature has an indirect effect on O2 availability, the data showed that it did not affect expression of prolyl-4-hydroxylases and that induction of secondary dormancy by hypoxia at 15 °C or by high temperature in air involved separate signalling pathways. Induction by hypoxia at 15 °C appears to be more regulated by GA and less by ABA than the induction by high temperature. PMID:23519728

Leymarie, Juliette

2013-01-01

427

WRKY41 controls Arabidopsis seed dormancy via direct regulation of ABI3 transcript levels not downstream of ABA.  

PubMed

Although seed dormancy is an important agronomic trait, its molecular basis is poorly understood. ABSCISIC ACID INSENSITIVE 3 (ABI3) plays an essential role in the establishment of seed dormancy. Here, we show that the lack of a seed-expressed WRKY transcription factor, WRKY41, confers reduced primary seed dormancy and thermoinhibition, phenotypes resembling those for a lack of ABI3. Loss-of-function abi3-17 and wrky41 alleles also both confer reduced sensitivity to ABA during germination and early seedling growth. Absence of WRKY41 decreases ABI3 transcript abundance in maturing and imbibed seeds, whereas transgenically overexpressing WRKY41 increases ABI3 expression. Moreover, transgenic overexpression of ABI3 completely restores seed dormancy phenotypes on wrky41. ChIP-qPCR and EMSA reveal that WRKY41 binds directly to the ABI3 promoter through three adjacent W-boxes, and a transactivation assay indicates that these W-boxes are essential for ABI3 expression. Whilst RT-qPCR analysis shows that the regulation of ABI3 by WRKY41 is not through ABA and other factors known to promote ABI3 transcription during seed maturation and germination, we also show that high concentrations of ABA might promote negative feedback regulation of WRKY41 expression. Finally, analysis of the wrky41 aba2 double mutant confirms that WRKY41 and ABA collaboratively regulate ABI3 expression and seed dormancy. In summary, our results demonstrate that WRKY41 is an important regulator of ABI3 expression, and hence of seed dormancy. PMID:24946881

Ding, Zhong Jie; Yan, Jing Ying; Li, Gui Xin; Wu, Zhong Chang; Zhang, Shu Qun; Zheng, Shao Jian

2014-09-01

428

Variation in the Loss of Seed Dormancy during After-ripening of Wild and Cultivated Rice Species  

PubMed Central

• Background and Aims The aim of this paper was to verify the variation in the loss of seed dormancy during after-ripening and the interspecific and interpopulation variability in the degree of dormancy of seven wild and two cultivated rice species comprising 21 populations and two cultivars. • Methods Four wild rice species from South America, Oryza glumaepatula, O. latifolia, O. grandiglumis and O. alta, and two O. sativa cultivars were tested in one experiment. In a second experiment, five wild species, O. punctata, O. eichingeri, O.rufipogon, O. latifolia and O. glumaepatula, and one cultivated species (O. glaberrima) were evaluated. Initial germination tests were performed soon after the seeds were harvested and subsequently at 2-month intervals, for a total of six storage periods in the first experiment and three in the second. All tests were conducted in the dark at a temperature of 27 °C. • Key Results Different patterns of after-ripening among populations within and between species were observed. • Conclusions The cultivated species (O. sativa and O. glaberrima) and, amongst the wild species, the tetraploids O. latifolia, O. grandiglumis and the diploids O. eichingeri and O. punctata, had weak dormancy, losing it completely 2 months after harvest, while O. rufipogon and O. glumaepatula exhibited pronounced dormancy. The latter showed different patterns of after-ripening between populations indigenous to the Amazon region and those originating in the Paraguay River system. Seeds of Solimões (Amazon) and Japura origin showed weak dormancy whereas those of Paraguay origin showed deep dormancy. Ecological differences among natural habitats may be involved in such differentiation. PMID:15471820

VEASEY, E. A.; KARASAWA, M. G.; SANTOS, P. P.; ROSA, M. S.; MAMANI, E.; OLIVEIRA, G. C. X.

2004-01-01

429

Bloodcount returns to normal with Gleevec, Bud and YvonneSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

Interviewee: Bud and Yvonne DNAi Location:Applications>Genes and medicine>drug design>Bud's Story>A Breakthrough A breakthrough CML causes an increased production of white blood cells. Bud and Yvonne talk about the breakthrough that brought Bud's white blood cell count back to normal.

2008-03-26

430

Paediatric entrance doses from exposure index in computed radiography  

NASA Astrophysics Data System (ADS)

Over the last two years we have evaluated paediatric patient doses in projection radiography derived from exposure level (EL) in computed radiography (CR) in a large university hospital. Entrance surface air kerma (ESAK) for 3501 paediatric examinations was calculated from the EL, which is a dose index parameter related to the light emitted by the phosphor-stimulable plate, archived in the Digital Imaging and Communications in Medicine (DICOM) header of the images and automatically transferred to a database using custom-built dedicated software. Typical mean thicknesses for several age bands of paediatric patients was estimated to calculate ESAK from the EL values, using results of experimental measurements with phantoms for the typical x-ray beam qualities used in paediatric examinations. Mean/median ESAK values (in µGy) for the age bands of <1 year, 1-5 years, 6-10 years and 11-15 years have been obtained for chest without a bucky: 51/41, 57/34, 91/54 and 122/109; chest with a bucky (for only the last three age bands): 114/87, 129/105 and 219/170; abdomen: 119/91, 291/225, 756/600 and 1960/1508 and pelvis: 65/48, 455/314, 943/707 and 2261/1595. Sample sizes of clinical images used for the (indirect) measurements were 1724 for chest without a bucky, 799 for chest with a bucky, 337 for abdomen and 641 for pelvis. The methodology we describe could be applicable to other centres using CR as an imaging modality for paediatrics. Presently, this method is the only practical approach to automatically extract parameters contained in the DICOM header, for the calculation of patient dose values for the CR modality.

Vano, E.; Martinez, D.; Fernandez, J. M.; Ordiales, J. M.; Prieto, C.; Floriano, A.; Ten, J. I.

2008-06-01

431

No exit: targeting the budding process to inhibit filovirus replication.  

PubMed

The filoviruses, Ebola and Marburg, cause severe hemorrhagic fever in humans and nonhuman primates, with high mortality rates. Although the filovirus replication pathway is now understood in considerable detail, no antiviral drugs have yet been developed that directly inhibit steps in the replication cycle. One potential target is the filovirus VP40 matrix protein, the key viral protein that drives the budding process, in part by mediating specific virus-host interactions to facilitate the efficient release of virions from the infected cell. This review will summarize current knowledge of key structural and functional domains of VP40 believed to be necessary for efficient budding of virions and virus-like particles. A better understanding of the structure and function of these key regions of VP40 will be crucial, as they may represent novel and rational targets for inhibitors of filovirus egress. PMID:19114059

Harty, Ronald N

2009-03-01

432

No exit: targeting the budding process to inhibit filovirus replication  

PubMed Central

The filoviruses, Ebola and Marburg, cause severe hemorrhagic fever in humans and nonhuman primates, with high mortality rates. Although the filovirus replication pathway is now understood in considerable detail, no antiviral drugs have yet been developed that directly inhibit steps in the replication cycle. One potential target is the filovirus VP40 matrix protein, the key viral protein that drives the budding process, in part by mediating specific virus-host interactions to facilitate the efficient release of virions from the infected cell. This review will summarize current knowledge of key structural and functional domains of VP40 believed to be necessary for efficient budding of virions and virus-like particles. A better understanding of the structure and function of these key regions of VP40 will be crucial, as they may represent novel and rational targets for inhibitors of filovirus egress. PMID:19114059

Harty, Ronald N.

2009-01-01

433

bud96ov -- Fiscal Year 1996 Congressional Budget Request Overview  

NSF Publications Database

Figure 2 Upholding World Leadership NSF Share of Total Federal Support for Basic Research at Academic Institutions and for Mathematics and Science Education (FIG 2 HERE) Download file bud96ov.xls NSF's FY 1996 request includes a balanced set of investments that will help uphold the agency?s leadership role in fundamental research and education. NSF's FY 1996 budget will also provide for sustained investments in other programs that foster partnerships, including Engineering Research Centers, ...

434

Mise en place-this bud's for the Golgi.  

PubMed

Selective cargo export from the endoplasmic reticulum is brought about by the budding of COPII vesicles. While the main structural components of the COPII coat have been identified and characterized, the regulatory event(s) promoting COPII vesicle biogenesis and cargo selection still remains largely unknown. New data by Glick and colleagues suggest that Sec12 and COPII function may be downstream of important early events coordinated by transitional ER (tER) exit sites. PMID:15149587

LaPointe, Paul; Gurkan, Cemal; Balch, William E

2004-05-21

435

The Inside-Out Mechanism of Dicers from Budding Yeasts  

SciTech Connect

The Dicer ribonuclease III (RNase III) enzymes process long double-stranded RNA (dsRNA) into small interfering RNAs (siRNAs) that direct RNA interference. Here, we describe the structure and activity of a catalytically active fragment of Kluyveromyces polysporus Dcr1, which represents the noncanonical Dicers found in budding yeasts. The crystal structure revealed a homodimer resembling that of bacterial RNase III but extended by a unique N-terminal domain, and it identified additional catalytic residues conserved throughout eukaryotic RNase III enzymes. Biochemical analyses showed that Dcr1 dimers bind cooperatively along the dsRNA substrate such that the distance between consecutive active sites determines the length of the siRNA products. Thus, unlike canonical Dicers, which successively remove siRNA duplexes from the dsRNA termini, budding-yeast Dicers initiate processing in the interior and work outward. The distinct mechanism of budding-yeast Dicers establishes a paradigm for natural molecular rulers and imparts substrate preferences with ramifications for biological function.

Weinberg, David E.; Nakanishi, Kotaro; Patel, Dinshaw J.; Bartel, David P. (Whitehead); (MSKCC)

2011-09-20

436

The Inside-Out Mechanism of Dicers from Budding Yeasts  

SciTech Connect

The Dicer ribonuclease III (RNase III) enzymes process long double-stranded RNA (dsRNA) into small interfering RNAs (siRNAs) that direct RNA interference. Here, we describe the structure and activity of a catalytically active fragment of Kluyveromyces polysporus Dcr1, which represents the noncanonical Dicers found in budding yeasts. The crystal structure revealed a homodimer resembling that of bacterial RNase III but extended by a unique N-terminal domain, and it identified additional catalytic residues conserved throughout eukaryotic RNase III enzymes. Biochemical analyses showed that Dcr1 dimers bind cooperatively along the dsRNA substrate such that the distance between consecutive active sites determines the length of the siRNA products. Thus, unlike canonical Dicers, which successively remove siRNA duplexes from the dsRNA termini, budding-yeast Dicers initiate processing in the interior and work outward. The distinct mechanism of budding-yeast Dicers establishes a paradigm for natural molecular rulers and imparts substrate preferences with ramifications for biological function.

D Weinberg; K Nakanishi; D Patel; D Bartel

2011-12-31

437

Paramyxovirus Assembly and Budding: Building Particles that Transmit Infections  

PubMed Central

The paramyxoviruses define a diverse group of enveloped RNA viruses that includes a number of important human and animal pathogens. Examples include human respiratory syncytial virus and the human parainfluenza viruses, which cause respiratory illnesses in young children and the elderly; measles and mumps viruses, which have caused recent resurgences of disease in developed countries; the zoonotic Hendra and Nipah viruses, which have caused several outbreaks of fatal disease in Australia and Asia; and Newcastle disease virus, which infects chickens and other avian species. Like other enveloped viruses, paramyxoviruses form particles that assemble and bud from cellular membranes, allowing the transmission of infections to new cells and hosts. Here, we review recent advances that have improved our understanding of events involved in paramyxovirus particle formation. Contributions of viral matrix proteins, glycoproteins, nucleocapsid proteins, and accessory proteins to particle formation are discussed, as well as the importance of host factor recruitment for efficient virus budding. Trafficking of viral structural components within infected cells is described, together with mechanisms that allow for the selection of specific sites on cellular membranes for the coalescence of viral proteins in preparation of bud formation and virion release. PMID:20398786

Harrison, Megan S.; Sakaguchi, Takemasa; Schmitt, Anthony P.

2010-01-01

438

Antagonistic Action of Strigolactone and Cytokinin in Bud Outgrowth Control1[W  

PubMed Central

Cytokinin (CK) has long been implicated as a promoter of bud outgrowth in plants, but exactly how this is achieved in coordination with other plant hormones is unclear. The recent discovery of strigolactones (SLs) as the long-sought branch-inhibiting hormone allowed us to test how CK and SL coordinately regulate bud outgrowth in pea (Pisum sativum). We found that SL-deficient plants are more sensitive to stimulation of bud growth by low concentrations of locally applied CK than wild-type plants. Furthermore, in contrast with SL mutant plants, buds of wild-type plants are almost completely resistant to stimulation by CK supplied to the vasculature. Regardless of whether the exogenous hormones were supplied locally or to the xylem stream, SL and CK acted antagonistically on bud outgrowth. These data suggest that SLs do not affect the delivery of CK to axillary buds and vice versa. Rather, these data combined with dose-response experiments suggest that SLs and CK can act directly in buds to control their outgrowth. These hormones may converge at a common point in the bud outgrowth regulatory pathway. The expression of pea BRANCHED1, a TCP transcription factor expressed strongly in buds and thought to act downstream of SLs in shoot branching, is regulated by CK and SL without a requirement for protein synthesis and in a manner that correlates with observed bud growth responses. PMID:22042819

Dun, Elizabeth A.; de Saint Germain, Alexandre; Rameau, Catherine; Beveridge, Christine A.

2012-01-01

439

Role of protein and mRNA oxidation in seed dormancy and germination  

PubMed Central

Reactive oxygen species (ROS) are key players in the regulation of seed germination and dormancy. Although their regulated accumulation is a prerequisite for germination, the cellular basis of their action remains unknown, but very challenging to elucidate due to the lack of specificity of these compounds that can potentially react with all biomolecules. Among these, nucleic acids and proteins are very prone to oxidative damage. RNA is highly sensitive to oxidation because of its single-stranded structure and the absence of a repair system. Oxidation of mRNAs induces their decay through processing bodies or results in the synthesis of aberrant proteins through altered translation. Depending on the oxidized amino acid, ROS damage of proteins can be irreversible (i.e., carbonylation) thus triggering the degradation of the oxidized proteins by the cytosolic 20S proteasome or can be reversed through the action of thioredoxins, peroxiredoxins, or glutaredoxins (cysteine oxidation) or by methionine sulfoxide reductase (methionine oxidation). Seed dormancy alleviation in the dry state, referred to as after-ripening, requires both selective mRNA oxidation and protein carbonylation. Similarly, seed imbibition of non-dormant seeds is associated with targeted oxidation of a subset of proteins. Altogether, these specific features testify that such oxidative modifications play important role in commitment of the cellular functioning toward germination completion. PMID:23579315

El-Maarouf-Bouteau, Hayat; Meimoun, Patrice; Job, Claudette; Job, Dominique; Bailly, Christophe

2013-01-01

440

The Dormancy Regulator DosR Controls Ribosome Stability in Hypoxic Mycobacteria*  

PubMed Central

It is thought that during latent infection, Mycobacterium tuberculosis bacilli are retained within granulomas in a low-oxygen environment. The dormancy survival (Dos) regulon, regulated by the response regulator DosR, appears to be essential for hypoxic survival in M. tuberculosis, but it is not known how the regulon promotes survival. Here we report that mycobacteria, in contrast to enteric bacteria, do not form higher-order structures (e.g. ribosomal dimers) upon entry into stasis. Instead, ribosomes are stabilized in the associated form (70S). Using a strategy incorporating microfluidic, proteomic, and ribosomal profiling techniques to elucidate the fate of mycobacterial ribosomes during hypoxic stasis, we show that the dormancy regulator DosR is required for optimal ribosome stabilization. We present evidence that the majority of this effect is mediated by the DosR-regulated protein MSMEG_3935 (a S30AE domain protein), which is associated with the ribosome under hypoxic conditions. A ?3935 mutant phenocopies the ?dosR mutant during hypoxia, and complementation of ?dosR with the MSMEG_3935 gene leads to complete recovery of dosR mutant phenotypes during hypoxia. We suggest that this protein is named ribosome-associated factor under hypoxia (RafH) and that it is the major factor responsible for DosR-mediated hypoxic survival in mycobacteria. PMID:22544737

Trauner, Andrej; Lougheed, Kathryn E. A.; Bennett, Mark H.; Hingley-Wilson, Suzanne M.; Williams, Huw D.

2012-01-01

441

Trancriptional landscape of Aspergillus niger at breaking of conidial dormancy revealed by RNA-sequencing  

PubMed Central

Background Genome-wide analysis was performed to assess the transcriptional landscape of germinating A. niger conidia using both next generation RNA-sequencing and GeneChips. The metabolism of storage compounds during conidial germination was also examined and compared to the transcript levels from associated genes. Results The transcriptome of dormant conidia was shown to be highly differentiated from that of germinating conidia and major changes in response to environmental shift occurred within the first hour of germination. The breaking of dormancy was associated with increased transcript levels of genes involved in the biosynthesis of proteins, RNA turnover and respiratory metabolism. Increased transcript levels of genes involved in metabolism of nitrate at the onset of germination implies its use as a source of nitrogen. The transcriptome of dormant conidia contained a significant component of antisense transcripts that changed during germination. Conclusion Dormant conidia contained transcripts of genes involved in fermentation, gluconeogenesis and the glyoxylate cycle. The presence of such transcripts in dormant conidia may indicate the generation of energy from non-carbohydrate substrates during starvation-induced conidiation or for maintenance purposes during dormancy. The immediate onset of metabolism of internal storage compounds after the onset of germination, and the presence of transcripts of relevant genes, suggest that conidia are primed for the onset of germination. For some genes, antisense transcription is regulated in the transition from resting conidia to fully active germinants. PMID:23577966

2013-01-01

442

Effects of temperature and photoperiod on postponing bermudagrass (Cynodon dactylon [L.] Pers.) turf dormancy.  

PubMed

Growth chamber and field experiments were carried out to determine the effects of extended photoperiod under low and freezing temperatures on bermudagrass turf dormancy at Bajgah, in the southern part of Iran. The experiment in the growth chamber was conducted with four temperature regimes (15, 7.5, 0 and -7.5°C) and three light durations (8, 12 and 16h) in a completely randomized design with four replications. The field study was conducted in two consecutive years (2008-2009) with three light durations (8, 12 and 16h) in months with natural short day length and arranged in a randomized complete blocks design with three replications. Results in both experiments showed that decreasing temperature and photoperiod decreased verdure fresh and dry weight, shoot height, tiller density, leaf area and chlorophyll and relative water contents (RWC). However, rooting depth and fresh weight of roots increased in the growth chamber. Decreasing the temperature and light duration increased electrolyte leakage and proline content. Reducing sugars increased with decreasing temperature and declined with lowering light duration in both shoots and roots. Starch content of both shoots and roots showed an adverse trend compared to reducing sugars; starch content increased in both shoots and roots in all treatments by shortening the photoperiod. Practically, the problem of bermudagrass turf's dormancy could be solved via increasing the photoperiod in months with short day lengths. This treatment would be efficient and useful for turfgrass managers to apply in landscapes and stadiums. PMID:22465814

Esmaili, Somayeh; Salehi, Hassan

2012-06-15

443

Model of Tumor Dormancy/Recurrence after Short-Term Chemotherapy  

PubMed Central

Although many tumors regress in response to neoadjuvant chemotherapy, residual tumor cells are detected in most cancer patients post-treatment. These residual tumor cells are thought to remain dormant for years before resuming growth, resulting in tumor recurrence. Considering that recurrent tumors are most often responsible for patient mortality, there exists an urgent need to study signaling pathways that drive tumor dormancy/recurrence. We have developed an in vitro model of tumor dormancy/recurrence. Short-term exposure of tumor cells (breast or prostate) to chemotherapy at clinically relevant doses enriches for a dormant tumor cell population. Several days after removing chemotherapy, dormant tumor cells regain proliferative ability and establish colonies, resembling tumor recurrence. Tumor cells from “recurrent” colonies exhibit increased chemotherapy resistance, similar to the therapy resistance of recurrent tumors in cancer patients. Previous studies using long-term chemotherapy selection models identified acquired mutations that drive tumor resistance. In contrast, our short term chemotherapy exposure model enriches for a slow-cycling, dormant, chemo-resistant tumor cell sub-population that can resume growth after drug removal. Studying unique signaling pathways in dormant tumor cells enriched by short-term chemotherapy treatment is expected to identify novel therapeutic targets for preventing tumor recurrence. PMID:24845582

Li, Shenduo; Kennedy, Margaret; Payne, Sturgis; Kennedy, Kelly; Seewaldt, Victoria L.; Pizzo, Salvatore V.; Bachelder, Robin E.

2014-01-01

444

Transcriptomic analysis of the exit from dormancy of Aspergillus fumigatus conidia  

PubMed Central

Background Establishment of aspergillosis is depending upon the exit from dormancy and germination of the conidia of Aspergillus fumigatus in the lung. To gain an understanding of the molecular mechanisms underlying the early steps of conidial germination, we undertook a transcriptomic analysis using macroarrays constructed with PCR fragments from > 3,000 genes (around one third of the annotated A. fumigatus genome). Results Major results of this analysis are the following: (i) conidia stored pre-packaged mRNAs transcripts (27% of genes have transcripts in the resting conidia; (ii) incubation at 37°C in a nutritive medium induced up- and down-regulation of genes: 19% of the total number of genes deposited on the array were up-regulated whereas 22% of the genes with pre-packaged mRNA in the resting conidia were down-regulated; (iii) most modifications were seen during the first 30 min of germination whereas very little modification of gene expression occurred during the following hour; (iv) one-year old conidia and one-week old conidia behaved similarly at transcriptional level. Conclusion Transcriptomic data indicate that the exit from dormancy is associated with a shift from a fermentative metabolism to a respiratory metabolism as well as a trend toward immediate protein synthesis. PMID:18796135

Lamarre, Claude; Sokol, Serguei; Debeaupuis, Jean-Paul; Henry, Christine; Lacroix, Celine; Glaser, Philippe; Coppee, Jean-Yves; Francois, Jean-Marie; Latge, Jean-Paul

2008-01-01

445

Tissue factor expression provokes escape from tumor dormancy and leads to genomic alterations  

PubMed Central

The coagulation system links immediate (hemostatic) and late (inflammatory, angiogenic) tissue responses to injury, a continuum that often is subverted in cancer. Here we provide evidence that tumor dormancy is influenced by tissue factor (TF), the cancer cell-associated initiator of the coagulation system and a signaling receptor. Thus, indolent human glioma cells deficient for TF remain viable but permanently dormant at the injection site for nearly a year, whereas the expression of TF leads to a step-wise transition to latent and overt tumor growth phases, a process that is preceded by recruitment of vascular (CD105+) and myeloid (CD11b+ and F4/80+) cells. Importantly, the microenvironment orchestrated by TF expression drives permanent changes in the phenotype, gene-expression profile, DNA copy number, and DNA methylation state of the tumor cells that escape from dormancy. We postulate that procoagulant events in the tissue microenvironment (niche) may affect the fate of occult tumor cells, including their biological and genetic progression to initiate a full-blown malignancy. PMID:24520174

Magnus, Nathalie; Garnier, Delphine; Meehan, Brian; McGraw, Serge; Lee, Tae Hoon; Caron, Maxime; Bourque, Guillaume; Milsom, Chloe; Jabado, Nada; Trasler, Jacquetta; Pawlinski, Rafal; Mackman, Nigel; Rak, Janusz

2014-01-01

446

Gas exchange and ventilation during dormancy in the tegu lizard tupinambis merianae  

PubMed

The tegu lizard Tupinambis merianae exhibits an episodic ventilatory pattern when dormant at 17 degrees C but a uniform ventilatory pattern when dormant at 25 degrees C. At 17 degrees C, ventilatory episodes were composed of 1-22 breaths interspaced by non-ventilatory periods lasting 1.8-26 min. Dormancy at the higher body temperature was accompanied by higher rates of O(2) consumption and ventilation. The increase in ventilation was due only to increases in breathing frequency with no change observed in tidal volume. The air convection requirement for O(2) did not differ at the two body temperatures. The respiratory quotient was 0.8 at 17 degrees C and 1.0 at 25 degrees C. We found no consistent relationship between expired gas composition and the start/end of the ventilatory period during episodic breathing at 17 degrees C. However, following non-ventilatory periods of increasing duration, there was an increase in the pulmonary O(2) extraction that was not coupled to an equivalent increase in elimination of CO(2) from the lungs. None of the changes in the variables studied could alone explain the initiation/termination of episodic ventilation in the tegus, suggesting that breathing episodes are shaped by a complex interaction between many variables. The estimated oxidative cost of breathing in dormant tegus at 17 degrees C was equivalent to 52.3 % of the total metabolic rate, indicating that breathing is the most costly activity during dormancy. PMID:10574745

de Andrade DV; Abe

1999-12-01

447

East and West Elevations and Entrance Details U.S. Veterans ...  

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

East and West Elevations and Entrance Details - U.S. Veterans Hospital, Jefferson Barracks, Therapeutic Exercise Building, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

448

PennAccess: Laboratory for Research on the Structure of Matter Entrance Information  

E-print Network

PennAccess: Laboratory for Research on the Structure of Matter Entrance Information: 3231 Walnut. Hours: · The Laboratory for Research on the Structure of Matter is open to the public: Monday through

Plotkin, Joshua B.

449

Cotton embryogenesis: The entrance and discharge of the pollen tube in the embryo sac  

Microsoft Academic Search

An analysis of the entrance and discharge of the pollen tube into the embryo sac of Gossypium hirsutum was made with the light and electron microscopes. The following sequence of events is seen in cotton:

William A. Jensen; Donald B. Fisher

1967-01-01

450

Kommunikation und Marketing // August 2012 1 von 38 Abitur (higher education entrance qualification,  

E-print Network

Glossar Kommunikation und Marketing // August 2012 1 von 38 Abitur Abitur (higher education for Economics Allgemeine Hochschulreife general higher education entrance qualification Allgemeiner Assyriologie ancient Near Eastern studies with a focus on Assyriology #12;Glossar Kommunikation und Marketing

Heermann, Dieter W.

451

Components of variation, heritabilities and correlations for indices of sprouting tolerance and seed dormancy in Triticum spp  

Microsoft Academic Search

Germination of wheat (Triticum spp) kernels prior to harvest reduces the economic value of grain. Losses attributable to pre-harvest sprouting could be reduced by developing sprouting tolerant (ST) cultivars if heritable variation exists for this trait. Objectives of this study were to compare various assays that measure ST, seed dormancy (SD), and alpha-amylase activity, and to divide the total variation

R. M. DePauw; T. N. McCaig

1991-01-01

452

Immunogenicity of Eight Dormancy Regulon-Encoded Proteins of Mycobacterium tuberculosis in DNA-Vaccinated and Tuberculosis-Infected Mice  

Microsoft Academic Search

Hypoxia and low concentrations of nitric oxide have been reported to upregulate in vitro gene expression of 48 proteins of the dormancy (DosR) regulon of Mycobacterium tuberculosis. These proteins are thought to be essential for the survival of bacteria during persistence in vivo and are targeted by the immune system during latent infection in humans. Here we have analyzed the

Virginie Roupie; Marta Romano; Lei Zhang; Hannelie Korf; May Young Lin; Kees L. M. C. Franken; Tom H. M. Ottenhoff; Michel R. Klein; Kris Huygen

2007-01-01

453

Anatomy of Two Mechanisms of Breaking Physical Dormancy by Experimental Treatments in Seeds of Two North American Rhus Species (Anacardiaceae)  

Microsoft Academic Search

Anatomy of the endocarp was studied in relation to the physical dormancy-breaking mechanisms in experimentally treated Rhus aromatica var. aromatica and R. glabra germination units, which include seed plus endocarp (hereafter seeds). The endocarp has three distinct layers, with brachysclereids on the outside, osteosclereids in the middle, and macrosclereids on the inside. Brachysclereids in the carpellary micropyle region (i.e., region

Xiaojie Li; Jerry M. Baskin; Carol C. Baskin

1999-01-01

454

Variation within species and inter-species comparison of seed dormancy and germination of four annual Lamium species  

Microsoft Academic Search

In an ecological context, knowledge of intra-species variation in dormancy and germination is necessary both for practical and theoretical reasons. We used four or five seed batches (replicates) of four closely related annuals co-occurring in arable fields in Sweden: Lamium amplexicaule, L. confertum, L. hybridum and L. purpureum. Seeds used for experiments stemmed from plants cultivated on two sites, each

Laila M. Karlsson; Per Milberg

2008-01-01

455

Dormancy release during hydrated storage in Lolium rigidum seeds is dependent on temperature, light quality, and hydration status  

Microsoft Academic Search

The influence of temperature, light environment, and seed hydration on the rate of dormancy release in Lolium rigidum (annual ryegrass) seeds during hydrated storage (stratification) was investigated. In a series of experiments, seeds were subjected to a range of temperatures (nine between 5 ?C and 37 ?C), light (white, red, far-red, and dark), and hydration (4- 70 g H2O 100

Kathryn J. Steadman

2004-01-01

456

Adenine nucleotides and energy charge during dormancy breaking in embryo axes of Acer platanoides and Fagus sylvatica seeds  

Microsoft Academic Search

We analysed changes in AMP, ADP, and ATP concentrations and adenylate energy charge in Norway maple (Acer platanoides L.) and European beech (Fagus sylvatica L.) seeds during dormancy breaking (at 3 °C) and in the control variant at 15 °C. Values of the studied indicators in stratified\\u000a beech seeds were generally higher at 15 °C, at least until germination (+3

Kazimierz Krawiarz; Zofia Szczotka

2005-01-01

457

Interaction Between Seed Dormancy-release Mechanism, Environment and Seed Bank Strategy for a Widely Distributed Perennial Legume, Parkinsonia aculeata (Caesalpinaceae)  

PubMed Central

Background and Aims Parkinsonia aculeata (Caesalpinaceae) is a perennial legume with seeds that have hard-seeded (physical) dormancy and are potentially very long-lived. Seed dormancy is a characteristic that can both help maximize the probability of seedling establishment and spread the risk of recruitment failure across years (bet-hedging). In this study, dormancy-release patterns are described across the diverse environments in which this species occurs in order to test whether wet heat (incubation under wet, warm-to-hot, conditions) alone can explain those patterns, and in order to determine the likely ecological role of physical dormancy across this species distribution. Methods A seed burial trial was conducted across the full environmental distribution of P. aculeata in Australia (arid to wet-dry tropics, uplands to wetlands, soil surface to 10 cm deep). Key Results Wet heat explained the pattern of dormancy release across all environments. Most seeds stored in the laboratory remained dormant throughout the trial (at least 84 %). Dormancy release was quickest for seeds buried during the wet season at relatively high rainfall, upland sites (only 3 % of seeds remained dormant after 35 d). The longest-lived seeds were in wetlands (9 % remained dormant after almost 4 years) and on the soil surface (57 % after 2 years). There was no consistent correlation between increased aridity and rate of dormancy release. Conclusions The results suggest that physical dormancy in P. aculeata is a mechanism for maximizing seedling establishment rather than a bet-hedging strategy. However, seed persistence can occur in environmental refuges where dormancy-release cues are weak and conditions for germination and establishment are poor (e.g. under dense vegetation or in more arid micro-environments) or unsuitable (e.g. when seeds are inundated or on the soil surface). Risks of recruitment failure in suboptimal environments could therefore be reduced by inter-year fluctuations in microclimate or seed movement. PMID:18558626

Van Klinken, Rieks D.; Lukitsch, Bert; Cook, Carly

2008-01-01

458

Quantitative description of the effect of stratification on dormancy release of grape seeds in response to various temperatures and water contents  

PubMed Central

The effect of stratification on dormancy release of grape seeds crossing from the sub- to the supraoptimal range of temperatures and water contents was analysed by modified threshold models. The stratification impacted on dormancy release in three different ways: (i) dormancy was consistently released with prolonged stratification time when stratified at temperatures of <15?°C; (ii) at 15?°C and 20?°C, the stratification effect initially increased, and then decreased with extended time; and (iii) stratification at 25?°C only reduced germinable seeds. These behaviours indicated that stratification could not only release primary dormancy but also induce secondary dormancy in grape seed. The rate of dormancy release changed linearly in two phases, while induction increased exponentially with increasing temperature. The thermal time approaches effectively quantified dormancy release only at suboptimal temperature, but a quantitative method to integrate the occurrence of dormancy release and induction at the same time could describe it well at either sub- or supraoptimal temperatures. The regression with the percentage of germinable seeds versus stratification temperature or water content within both the sub- and supraoptimal range revealed how the optimal temperature (Tso) and water content (Wso) for stratification changed. The Tso moved from 10.6?°C to 5.3?°C with prolonged time, while Wso declined from >0.40?g H2O g DW?1 at 5?°C to ?0.23?g H2O g DW?1 at 30?°C. Dormancy release in grape seeds can occur across a very wide range of conditions, which has important implications for their ability to adapt to a changeable environment in the wild. PMID:19491305

Wang, W. Q.; Song, S. Q.; Li, S. H.; Gan, Y. Y.; Wu, J. H.; Cheng, H. Y.

2009-01-01

459

Water content: a key factor of the induction of secondary dormancy in barley grains as related to ABA metabolism.  

PubMed

Primary dormant barley (Hordeum vulgare) grains germinate at 10-15°C but not at 30°C, and there exist a positive correlation between embryo ABA content after 24?h on water and the depth of dormancy. Incubation at 30°C results in a progressive loss of the ability to germinate at 15°C. This induction of a secondary dormancy is optimal after 3?days and requires an embryo water content higher than 0.50?g H?O g?¹ DW, this corresponding with activation of the cell cycle. There exists no correlation between ABA content after 3?days at 30°C and the induction of secondary dormancy. However, at high water content (1.60-1.87?g H?O g?¹ DW), secondary dormancy is associated with an high embryo ABA content after transfer to 15°C, resulting from an increase in HvNCED1 and HvNCED2 expression and a decrease in HvABA8'OH-1. Such changes are not observed at 0.45?g H?O g?¹ DW. Incubation at 30°C also results in an increase in expression of genes involved in GA catabolism (HvGA2ox1, HvGA2ox3 and HvGA2ox5) and synthesis (HvGA3ox2, HvGA20ox1 and HvGA20ox3). The HvGA3ox2/HvGA2ox3 transcript ratio remains low (0.27-0.37) at 30°C and after transfer to 15°C in secondary dormant seeds, but it is higher than two when secondary dormancy is not induced. Changes in HvExpA11 expression indicate that GA signaling decreases when a secondary dormancy is expressed. Our results clearly indicate that expression of genes involved in ABA and GA metabolism differs in primary and secondary dormancies and furthermore, their expression is related to embryo water content. PMID:23061651

Hoang, Hai Ha; Sotta, Bruno; Gendreau, Emmanuel; Bailly, Christophe; Leymarie, Juliette; Corbineau, Françoise

2013-06-01

460

Reconstituting ring-rafts in bud-mimicking topography of model membranes  

NASA Astrophysics Data System (ADS)

During vesicular trafficking and release of enveloped viruses, the budding and fission processes dynamically remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud topography in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the dynamic membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud topography in the so