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Sample records for pretreated root tips

  1. Cytology of root tips of Dioscoreophyllum cumminsii (STAPF) diel ...

    African Journals Online (AJOL)

    , University of Nigeria Nsukka. Root tips for the chromosome work were obtained from three sources: runners originating from main vine; sprouting pieces of tubers and redifferentiated root tips from callus. The results showed that normal ...

  2. Onion root tip cell system for biodosimetry?

    International Nuclear Information System (INIS)

    Paradiz, J; Druskovic, B.; Lovka, M.; Skrk, J.

    1996-01-01

    Methodology for radiation dose assessment based on chromosomal damage to plant cells has no yet been established, although root meristems have been the pioneer cytogenetic materials and profound analyses of irradiated meristematic cells of horse bean (Viciafaba L.) had been performed. Onion (Allium cepa L.) root tips frequently used for radiation cytogenetic studies, are recently considered to be one of the most promising plant test system for the detection of genotoxic environmental pollutants. We studied the possibility of using cytogenetic analyses of irradiated onion cells to determine the effective biological dose of ionizing radiation. The dose-effect relationships for chromosomal damages to onion meristematic cells were established after plants had been irradiated and subsequently grown in both laboratory and field conditions

  3. Building a hair: tip growth in Arabidopsis thaliana root hairs.

    OpenAIRE

    Carol, Rachel J; Dolan, Liam

    2002-01-01

    The Arabidopsis thaliana root hair is used as a model for studying tip growth in plants. We review recent advances, made using physiological and genetic approaches, which give rise to different, yet compatible, current views of the establishment and maintenance of tip growth in epidermal cells. For example, an active calcium influx channel localized at the tip of Arabidopsis root hairs has been identified by patch-clamp measurements. Actin has been visualized in vivo in Arabidopsis root hairs...

  4. Disproportionate abundance between ectomycorrhizal root tips and their associated mycelia

    DEFF Research Database (Denmark)

    Kjøller, Rasmus

    2006-01-01

    compared the ectomycorrhizal external mycelial community with the adjacent root-tip community in a Danish beech forest. Sand-filled in-growth mesh bags were used to trap external mycelia by incubating the mesh bags in the soil for 70 days. The adjacent ectomycorrhizal root-tip communities were recorded...

  5. Effects of cloning and root-tip size on observations of fungal ITS sequences from Picea glauca roots

    Science.gov (United States)

    Daniel L. Lindner; Mark T. Banik

    2009-01-01

    To better understand the effects of cloning on observations of fungal ITS sequences from Picea glauca (white spruce) roots two techniques were compared: (i) direct sequencing of fungal ITS regions from individual root tips without cloning and (ii) cloning and sequencing of fungal ITS regions from individual root tips. Effect of root tip size was...

  6. Patterns of auxin and abscisic acid movement in the tips of gravistimulated primary roots of maize

    Science.gov (United States)

    Young, L. M.; Evans, M. L.

    1996-01-01

    Because both abscisic acid (ABA) and auxin (IAA) have been suggested as possible chemical mediators of differential growth during root gravitropism, we compared with redistribution of label from applied 3H-IAA and 3H-ABA during maize root gravitropism and examined the relative basipetal movement of 3H-IAA and 3H-ABA applied to the caps of vertical roots. Lateral movement of 3H-ABA across the tips of vertical roots was non-polar and about 2-fold greater than lateral movement of 3H-IAA (also non-polar). The greater movement of ABA was not due to enhanced uptake since the uptake of 3H-IAA was greater than that of 3H-ABA. Basipetal movement of label from 3H-IAA or 3H-ABA applied to the root cap was determined by measuring radioactivity in successive 1 mm sections behind the tip 90 minutes after application. ABA remained largely in the first mm (point of application) whereas IAA was concentrated in the region 2-4 mm from the tip with substantial levels found 7-8 mm from the tip. Pretreatment with inhibitors of polar auxin transport decreased both gravicurvature and the basipetal movement of IAA. When roots were placed horizontally, the movement of 3H-IAA from top to bottom across the cap was enhanced relative to movement from bottom to top whereas the pattern of movement of label from 3H-ABA was unaffected. These results are consistent with the hypothesis that IAA plays a role in root gravitropism but contrary to the idea that gravi-induced asymmetric distribution of ABA contributes to the response.

  7. Building a hair: tip growth in Arabidopsis thaliana root hairs.

    Science.gov (United States)

    Carol, Rachel J; Dolan, Liam

    2002-06-29

    The Arabidopsis thaliana root hair is used as a model for studying tip growth in plants. We review recent advances, made using physiological and genetic approaches, which give rise to different, yet compatible, current views of the establishment and maintenance of tip growth in epidermal cells. For example, an active calcium influx channel localized at the tip of Arabidopsis root hairs has been identified by patch-clamp measurements. Actin has been visualized in vivo in Arabidopsis root hairs by using a green-fluorescent-protein-talin reporter and shown to form a dense mesh in the apex of the growing tip. The kojak gene, which encodes a protein similar to the catalytic subunit of cellulose synthase, is needed in the first stages of hair growth. A role for LRX1, a leucine-rich repeat extensin, in determining the morphology of the cell wall of root hairs has been established using reverse genetics. The new information can be integrated into a general and more advanced view of how these specialized plant cells grow.

  8. Abscisic Acid Regulates Auxin Homeostasis in Rice Root Tips to Promote Root Hair Elongation

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2017-06-01

    Full Text Available Abscisic acid (ABA plays an essential role in root hair elongation in plants, but the regulatory mechanism remains to be elucidated. In this study, we found that exogenous ABA can promote rice root hair elongation. Transgenic rice overexpressing SAPK10 (Stress/ABA-activated protein kinase 10 had longer root hairs; rice plants overexpressing OsABIL2 (OsABI-Like 2 had attenuated ABA signaling and shorter root hairs, suggesting that the effect of ABA on root hair elongation depends on the conserved PYR/PP2C/SnRK2 ABA signaling module. Treatment of the DR5-GUS and OsPIN-GUS lines with ABA and an auxin efflux inhibitor showed that ABA-induced root hair elongation depends on polar auxin transport. To examine the transcriptional response to ABA, we divided rice root tips into three regions: short root hair, long root hair and root tip zones; and conducted RNA-seq analysis with or without ABA treatment. Examination of genes involved in auxin transport, biosynthesis and metabolism indicated that ABA promotes auxin biosynthesis and polar auxin transport in the root tip, which may lead to auxin accumulation in the long root hair zone. Our findings shed light on how ABA regulates root hair elongation through crosstalk with auxin biosynthesis and transport to orchestrate plant development.

  9. Attachment of Agrobacterium tumefaciens B6 and A. radiobacter K84 to Tomato Root Tips

    OpenAIRE

    Penalver, R.; Serra, M. T.; Duran-Vila, N.; Lopez, M. M.

    1996-01-01

    Agrobacterium tumefaciens B6 and the avirulent Agrobacterium radiobacter strain K84 attached to in vitro-cultured tomato root tips, but the binding of strain B6 to root tips was greater than the binding of strain K84. Strain K84 was not able to block the attachment of A. tumefaciens B6 to in vitro-cultured tomato root tips.

  10. Diversity of an ectomycorrhizal fungal community studied by a root tip and total soil DNA approach.

    Science.gov (United States)

    Landeweert, Renske; Leeflang, Paula; Smit, Eric; Kuyper, Thom

    2005-01-01

    Molecular methods based on soil DNA extracts are increasingly being used to study the fungal diversity of ectomycorrhizal (EM) fungal communities in soil. Contrary to EM root tip identification, the use of molecular methods enables identification of extramatrical mycelia in soil. To compare fungal diversity as determined by root tip identification and mycelial identification, six soil samples were analysed. Root tips were extracted from the six samples and after amplification, the basidiomycete diversity on the root tips was analysed by denaturing gradient gel electrophoresis (DGGE). The soil from the six samples was sieved, total soil DNA was extracted and after amplification, the basidiomycete diversity in the soil fractions was analysed by DGGE. Fourteen different bands were excised from the DGGE gel and sequenced; fungal taxon names could be assigned to eight bands. Out of a total of 14 fungal taxa detected in soil, 11 fungal taxa were found on root tips, of which seven were EM fungal taxa. To examine whether the sieving treatment would affect EM species diversity, two different sieve mesh sizes were used and in addition, the organic soil fraction was analysed separately. DGGE analysis showed no differences in banding pattern for the different soil fractions. The organic fraction gave the highest DGGE band intensities. This work demonstrates that there is a high correspondence between basidiomycete diversity detected by molecular analysis of root tips and soil samples, irrespective of the soil fraction being analysed.

  11. A novel tracking tool for the analysis of plant-root tip movements

    International Nuclear Information System (INIS)

    Russino, A; Ascrizzi, A; Popova, L; Tonazzini, A; Mancuso, S; Mazzolai, B

    2013-01-01

    The growth process of roots consists of many activities, such as exploring the soil volume, mining minerals, avoiding obstacles and taking up water to fulfil the plant's primary functions, that are performed differently, depending on environmental conditions. Root movements are strictly related to a root decision strategy, which helps plants to survive under stressful conditions by optimizing energy consumption. In this work, we present a novel image-analysis tool to study the kinematics of the root tip (apex), named analyser for root tip tracks (ARTT). The software implementation combines a segmentation algorithm with additional software imaging filters in order to realize a 2D tip detection. The resulting paths, or tracks, arise from the sampled tip positions through the acquired images during the growth. ARTT allows work with no markers and deals autonomously with new emerging root tips, as well as handling a massive number of data relying on minimum user interaction. Consequently, ARTT can be used for a wide range of applications and for the study of kinematics in different plant species. In particular, the study of the root growth and behaviour could lead to the definition of novel principles for the penetration and/or control paradigms for soil exploration and monitoring tasks. The software capabilities were demonstrated by experimental trials performed with Zea mays and Oryza sativa. (paper)

  12. Pollen tube and root-hair tip growth is disrupted in a mutant of Arabidopsis thaliana.

    Science.gov (United States)

    Schiefelbein, J; Galway, M; Masucci, J; Ford, S

    1993-11-01

    The expansion of both root hairs and pollen tubes occurs by a process known as tip growth. In this report, an Arabidopsis thaliana mutant (tip1) is described that displays defects in both root-hair and pollen-tube growth. The root hairs of the tip1 mutant plants are shorter than those of the wild-type plants and branched at their base. The tip1 pollen-tube growth defect was identified by the aberrant segregation ratio of phenotypically normal to mutant seeds in siliques from self-pollinated, heterozygous plants. Homozygous mutant seeds are not randomly distributed in the siliques, comprising only 14.4% of the total seeds, 5.3% of the seeds from the bottom half, and 2.2% of the seeds from the bottom quarter of the heterozygous siliques. Studies of pollen-tube growth in vivo showed that mutant pollen tubes grow more slowly than wild-type pollen through the transmitting tissue of wild-type flowers. Cosegregation studies indicate that the root-hair and pollen-tube defects are caused by the same genetic lesion. Based on these findings, the TIP1 gene is likely to encode a product involved in a fundamental aspect of tip growth in plant cells.

  13. Contact laser-assisted neuroendoscopy can be performed safely by using pretreated 'black' fibre tips: experimental data

    NARCIS (Netherlands)

    Willems, P. W.; Vandertop, W. P.; Verdaasdonk, R. M.; van Swol, C. F.; Jansen, G. H.

    2001-01-01

    Laser-assisted endoscopic neurosurgery by using conventional fibres requires the use of high-power laser light. Because this is potentially hazardous, we developed a pretreated fibre tip and evaluated tissue effects in vitro and in vivo. By applying a highly absorbing coating to the front of the

  14. 1-Aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC synthase expression in soybean roots, root tips, and soybean cyst nematode (Heterodera glycines)-infected roots.

    Science.gov (United States)

    Tucker, Mark L; Xue, Ping; Yang, Ronghui

    2010-01-01

    Colonization of plant roots by root knot and cyst nematodes requires a functional ethylene response pathway. However, ethylene plays many roles in root development and whether its role in nematode colonization is direct or indirect, for example lateral root initiation or root hair growth, is not known. The temporal requirement for ethylene and localized synthesis of ethylene during the life span of soybean cyst nematode (SCN) on soybean roots was further investigated. Although a significant increase in ethylene evolution was not detected from SCN-colonized roots, the concentration of the immediate precursor to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), was higher in SCN-colonized root pieces and root tips than in other parts of the root. Moreover, expression analysis of 17 ACC synthase (ACS) genes indicated that a select set of ACS genes is expressed in SCN-colonized root pieces that is clearly different from the set of genes expressed in non-colonized roots or root tips. Semi-quantitative real-time PCR indicated that ACS transcript accumulation correlates with the high concentration of ACC in root tips. In addition, an ACS-like sequence was found in the public SCN nucleotide database. Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS. Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested.

  15. Diversity of an ectomycorrhizal fungal community studied by a root tip and total soil DNA approach

    NARCIS (Netherlands)

    Landeweert, R.; Leeflang, P.; Smit, E.; Kuyper, T.W.

    2005-01-01

    Molecular methods based on soil DNA extracts are increasingly being used to study the fungal diversity of ectomycorrhizal (EM) fungal communities in soil. Contrary to EM root tip identification, the use of molecular methods enables identification of extramatrical mycelia in soil. To compare fungal

  16. Small RNA profiles in soybean primary root tips under water deficit.

    Science.gov (United States)

    Zheng, Yun; Hivrale, Vandana; Zhang, Xiaotuo; Valliyodan, Babu; Lelandais-Brière, Christine; Farmer, Andrew D; May, Gregory D; Crespi, Martin; Nguyen, Henry T; Sunkar, Ramanjulu

    2016-12-05

    Soybean (Glycine max) production is significantly hampered by frequent droughts in many regions of the world including the United States. Identifying microRNA (miRNA)-controlled posttranscriptional gene regulation under drought will enhance our understanding of molecular basis of drought tolerance in this important cash crop. Indeed, miRNA profiles in soybean exposed to drought were studied but not from the primary root tips, which is not only a main zone of water uptake but also critical for water stress sensing and signaling. Here we report miRNA profiles specifically from well-watered and water-stressed primary root tips (0 to 8 mm from the root apex) of soybean. Small RNA sequencing confirmed the expression of vastly diverse miRNA (303 individual miRNAs) population, and, importantly several conserved miRNAs were abundantly expressed in primary root tips. Notably, 12 highly conserved miRNA families were differentially regulated in response to water-deficit; six were upregulated while six others were downregulated at least by one fold (log2) change. Differentially regulated soybean miRNAs are targeting genes include auxin response factors, Cu/Zn Superoxide dismutases, laccases and plantacyanin and several others. These results highlighted the importance of miRNAs in primary root tips both under control and water-deficit conditions; under control conditions, miRNAs could be important for cell division, cell elongation and maintenance of the root apical meristem activity including quiescent centre whereas under water stress differentially regulated miRNAs could decrease auxin signaling and oxidative stress as well as other metabolic processes that save energy and water.

  17. Root-cause analysis of burner tip failures in coal-fired power plants

    International Nuclear Information System (INIS)

    Citirik, E.

    2014-01-01

    Warpage and complete or partial tear of burner material was frequently experienced in coal-fired power plants due to material overheating. Root-cause analysis of a burner tip failure is investigated employing stress modeling in the burner tip material in this study. The analyses performed in this research paper include heat transfer and stress analyses employing computational tools. Thermal analysis was performed using Computational Fluid Dynamics (CFD) software FLUENT for computing temperature distribution within the burner tip due to convection and radiation. Once the temperature distribution in the burner tip is determined, Finite Element Analysis (FEA) is employed using ANSYS to determine the maximum stress and deformations in burner tip material. Both FLUENT and ANSYS are numerical commercial simulation tools employed in this study. Large temperature gradients along the burner tip result in local bending stresses. These stresses resulting in creep stresses might be causing warpage in the burner tip. In this study, a design option was exercised to eliminate the excessive stress gradient in the burner tip material. Seven different FEA models were developed to simulate different operating conditions. Proposed design modification (Model 5) was able to reduce the maximum compressive stress from 76.09 MPa to 33.59 MPa. Significant reduction in the thermal stress due to design modification in Model 5 made author believe that the proposed design solution would eliminate the burner tip failures in this particular power plant. - Highlights: • Maximum stress and displacement values in the baseline model were computed. • Computations were performed using commercial FEA software ANSYS. • Different operating conditions were simulated in models 1-2-3-4. • Proposed geometry to prevent the failure is simulated in Models 5 and 6. • The proposed design solution reduced the maximum compressive stresses by ∼50%

  18. Enhancing auxin accumulation in maize root tips improves root growth and dwarfs plant height.

    Science.gov (United States)

    Li, Zhaoxia; Zhang, Xinrui; Zhao, Yajie; Li, Yujie; Zhang, Guangfeng; Peng, Zhenghua; Zhang, Juren

    2018-01-01

    Maize is a globally important food, feed crop and raw material for the food and energy industry. Plant architecture optimization plays important roles in maize yield improvement. PIN-FORMED (PIN) proteins are important for regulating auxin spatiotemporal asymmetric distribution in multiple plant developmental processes. In this study, ZmPIN1a overexpression in maize increased the number of lateral roots and inhibited their elongation, forming a developed root system with longer seminal roots and denser lateral roots. ZmPIN1a overexpression reduced plant height, internode length and ear height. This modification of the maize phenotype increased the yield under high-density cultivation conditions, and the developed root system improved plant resistance to drought, lodging and a low-phosphate environment. IAA concentration, transport capacity determination and application of external IAA indicated that ZmPIN1a overexpression led to increased IAA transport from shoot to root. The increase in auxin in the root enabled the plant to allocate more carbohydrates to the roots, enhanced the growth of the root and improved plant resistance to environmental stress. These findings demonstrate that maize plant architecture can be improved by root breeding to create an ideal phenotype for further yield increases. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  19. Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

    Science.gov (United States)

    Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

    2014-05-01

    Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses. Copyright © 2014. Published by Elsevier GmbH.

  20. Cytological changes of root tip cells of alfalfa seeds after space flight

    International Nuclear Information System (INIS)

    Ren Weibo; Xu Zhu; Chen Libo; Guo Huiqin; Wang Mi; Zhao Liang

    2008-01-01

    To understand the cytological effects of space flight on alfalfa seeds, dry seeds of three lines (Line 1, Line 2 and Line 4) were selected and loaded onto 'Shijian No.8' satellite for space flight. After returning to the ground, root tips of alfalfa were clipped and chromosome aberrations were observed by microscope. Data showed that space flight had two types of effect on cell mitotic: one was positive (Line 2, Line 4) and the other was negative (Line 1). Such chromosome aberrations were observed as micronucleus, chromosome bridge, fragments, lagging and so on. The frequency of aberration varied with the different materials. Conclusion was that space flight had significant effect on root tip cells, which mainly showed as the chromosome aberrations. (authors)

  1. PIXE analysis of mineral composition of alfalfa root-tip exposed to low pH or aluminum stress condition

    International Nuclear Information System (INIS)

    Yokota, Satoshi; Mae, Tadahiko; Ojima, Kunihiko; Ishii, Keizo.

    1994-01-01

    PIXE analysis was applied to study alteration of mineral composition (Al, P, K, and Cl) of alfalfa root-tip exposed to low pH or aluminum stress. These minerals were detectable using one or two pieces of root-tips. Short-term (within 4 h) decreases in K/P and Cl/P ratios were observed under low pH and aluminum stress conditions. However, degree of the decrease was not same. Differences in toxic effects of low pH and Al on the root-tip of alfalfa are discussed. (author)

  2. Enhancing auxin accumulation in maize root tips improves root growth and dwarfs plant height

    OpenAIRE

    Li, Zhaoxia; Zhang, Xinrui; Zhao, Yajie; Li, Yujie; Zhang, Guangfeng; Peng, Zhenghua; Zhang, Juren

    2017-01-01

    Summary Maize is a globally important food, feed crop and raw material for the food and energy industry. Plant architecture optimization plays important roles in maize yield improvement. PIN‐FORMED (PIN) proteins are important for regulating auxin spatiotemporal asymmetric distribution in multiple plant developmental processes. In this study, ZmPIN1a overexpression in maize increased the number of lateral roots and inhibited their elongation, forming a developed root system with longer semina...

  3. Changes in hormonal balance and meristematic activity in primary root tips on the slowly rotating clinostat and their effect on the development of the rapeseed root system.

    Science.gov (United States)

    Aarrouf, J; Schoevaert, D; Maldiney, R; Perbal, G

    1999-04-01

    The morphometry of the root system, the meristematic activity and the level of indole-3-acetic acid (IAA), abscisic acid (ABA) and zeatin in the primary root tips of rapeseed seedlings were analyzed as functions of time on a slowly rotating clinostat (1 rpm) or in the vertical controls (1 rpm). The fresh weight of the root system was 30% higher throughout the growth period (25 days) in clinorotated seedlings. Morphometric analysis showed that the increase in biomass on the clinostat was due to greater primary root growth, earlier initiation and greater elongation of the secondary roots, which could be observed even in 5-day-old seedlings. However, after 15 days, the growth of the primary root slowed on the clinostat, whereas secondary roots still grew faster in clinorotated plants than in the controls. At this time, the secondary roots began to be initiated closer to the root tip on the clinostat than in the control. Analysis of the meristematic activity and determination of the levels in IAA, ABA and zeatin in the primary root tips demonstrated that after 5 days on the clinostat, the increased length of the primary root could be the consequence of higher meristematic activity and coincided with an increase in both IAA and ABA concentrations. After 15 days on the clinostat, a marked increase in IAA, ABA and zeatin, which probably reached supraoptimal levels, seems to cause a progressive disturbance of the meristematic cells, during a decrease of primary root growth between 15 and 25 days. These modifications in the hormonal balance and the perturbation of the meristematic activity on the clinostat were followed by a loss of apical dominance, which was responsible for the early initiation of secondary roots, the greater elongation of the root system and the emergence of the lateral roots near the tip of the primary root.

  4. Selection for biocontrol bacteria antagonistic toward Rosellinia necatrix by enrichment of competitive avocado root tip colonizers.

    Science.gov (United States)

    Pliego, Clara; Cazorla, Francisco Manuel; González-Sánchez, María Angeles; Pérez-Jiménez, Rosa María; de Vicente, Antonio; Ramos, Cayo

    2007-06-01

    Biological control of soil-borne pathogens is frequently based on the application of antagonistic microorganisms selected solely for their ability to produce in vitro antifungal factors. The aim of this work was to select bacteria that efficiently colonize the roots of avocado plants and display antagonism towards Rosellinia necatrix, the causal agent of avocado white root rot. A high frequency of antagonistic strains (ten isolates, 24.4%) was obtained using a novel procedure based on the selection of competitive avocado root tip colonizers. Amplification and sequencing of the 16S rRNA gene, in combination with biochemical characterization, showed that eight and two of the selected isolates belonged to the genera Pseudomonas and Stenotrophomonas, respectively. Characterization of antifungal compounds produced by the antagonistic strains showed variable production of exoenzymes and HCN. Only one of these strains, Pseudomonas sp. AVO94, produced a compound that could be related to antifungal antibiotics. All of the ten selected strains showed twitching motility, a cell movement involved in competitive colonization of root tips. Production of N-acyl-homoserine lactones and indole-3-acetic acid was also reported for some of these isolates. Resistance to several bacterial antibiotics was tested, and three strains showing resistance to only one of them were selected for biocontrol assays. The three selected strains persisted in the rhizosphere of avocado plants at levels considered crucial for efficient biocontrol, 10(5)-10(6) colony forming units/g of root; two of them, Pseudomonas putida AVO102 and Pseudomonas pseudoalcaligenes AVO110, demonstrated significant protection of avocado plants against white root rot.

  5. Cytological effects of space flight on root-tip cells in rapeseed (Brassica napus L.)

    International Nuclear Information System (INIS)

    Xie Lin; Niu Yingze; Luo Yi

    2008-01-01

    The seed of rapeseed (Brassica napus L.) was carried by satellite 'Shijian 8'. The cytological effects of space mutation on the root-tip cells was studied in SP 1 generation. The results showed that the mitotic index, rate of chromosome aberration and rate of micronuclei were obviously increased in most of treated materials compared with the control, which indicated that true cytological mutations were induced by space flight. The mutagenic effects were observed higher in the maintainer lines than in the male sterile lines. (authors)

  6. Aphidicolin as synchronizing agent in root tip meristems of Haplopappus gracilis.

    Science.gov (United States)

    Galli, M G; Sala, F

    1983-06-01

    Aphidicolin, a reversible inhibitor of nuclear DNA replication, was tested as syncrhonizing agent in root tip meristems of Haplopappus gracilis. Embryos (i.e. decoated seeds) or 3-day-old seedlings were used to this purpose. After a 24 h treatment with the drug, a high level of synchrony was observed in both experimental materials for two cell cycles as assessed by determining the accumulation of cells in the S and M phases of the cycle. Highest synchronization was obtained with germinating embryos, possibly owing to a low degree of synchrony already existing in this system.

  7. Root tip morphology, anatomy, chemistry and potential hydraulic conductivity vary with soil depth in three temperate hardwood species.

    Science.gov (United States)

    Wang, Yan; Dong, Xueyun; Wang, Hongfeng; Wang, Zhengquan; Gu, Jiacun

    2016-01-01

    Root traits in morphology, chemistry and anatomy are important to root physiological functions, but the differences between shallow and deep roots have rarely been studied in woody plants. Here, we selected three temperate hardwood species, Juglans mandshurica Maxim., Fraxinus mandschurica Rupr. and Phellodendron amurense Rupr., in plantations in northeastern China and measured morphological, anatomical and chemical traits of root tips (i.e., the first-order roots) at surface (0-10 cm) and subsurface (20-30 cm) soil layers. The objectives of this study were to identify how those traits changed with soil depth and to reveal potential functional differences. The results showed that root diameters in deep root tips were greater in J. mandshurica and F. mandschurica, but smaller in P. amurense. However, root stele diameter and the ratio of stele to root diameter in the subsurface layer were consistently greater in all three species, which may enhance their abilities to penetrate into soil. All deep roots exhibited lower tissue nitrogen concentration and respiration rate, which were possibly caused by lower nutrient availability in the subsurface soil layer. Significant differences between shallow and deep roots were observed in xylem structure, with deep roots having thicker stele, wider maximum conduit and greater number of conduits per stele. Compared with shallow roots, the theoretical hydraulic conductivities in deep roots were enhanced by 133% (J. mandshurica), 78% (F. mandschurica) and 217% (P. amurense), respectively, indicating higher efficiency of transportation. Our results suggest that trees' root tip anatomical structure and physiological activity vary substantially with soil environment. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. The ZmRCP-1 promoter of maize provides root tip specific expression of transgenes in plantain.

    Science.gov (United States)

    Onyango, Stephen O; Roderick, Hugh; Tripathi, Jaindra N; Collins, Richard; Atkinson, Howard J; Oduor, Richard O; Tripathi, Leena

    2016-12-01

    Bananas and plantains (Musa spp.) provide 25 % of the food energy requirements for more than 100 million people in Africa. Plant parasitic nematodes cause severe losses to the crop due to lack of control options. The sterile nature of Musa spp. hampers conventional breeding but makes the crop suitable for genetic engineering. A constitutively expressed synthetic peptide in transgenic plantain has provided resistance against nematodes. Previous work with the peptide in potato plants indicates that targeting expression to the root tip improves the efficacy of the defence mechanism. However, a promoter that will provide root tip specific expression of transgenes in a monocot plant, such as plantain, is not currently available. Here, we report the cloning and evaluation of the maize root cap-specific protein-1 (ZmRCP-1) promoter for root tip targeted expression of transgenes that provide a defence against plant parasitic nematodes in transgenic plantain. Our findings indicate that the maize ZmRCP-1 promoter delivers expression of β-glucuronidase (gusA) gene in roots but not in leaves of transgenic plantains. In mature old roots, expression of gusA gene driven by ZmRCP-1 becomes limited to the root cap. Invasion by the nematode Radopholus similis does not modify Root Cap-specific Protein-1 promoter activity. Root cap-specific protein-1 promoter from maize can provide targeted expression of transgene for nematode resistance in transgenic plantain.

  9. Physiological effects of the form of nitrogen on corn root tips: a 31P nuclear magnetic resonance study

    International Nuclear Information System (INIS)

    Andrade, F.H.; Anderson, I.C.

    1986-01-01

    Physiological effects of different N forms (NO − 3 , NH + 4 , or a combination of both) on corn (Zea mays L.) root tips and leaves were studied by following 31 P signals with a nuclear magnetic resonance spectrometer. With root tips, both cytoplasmic and vacuolar pH could be measured, whereas with leaves, only vacuolar pH could be determined. The N treatments did not affect the cytoplasmic pH of corn root tips in contrast to proposals of previous workers. Leaf vacuolar pH was higher and root tip vacuolar pH lower with NO − 3 than with NH + 4 . Under anaerobic conditions, cytoplasmic pH was reduced because of lactic acid fermentation. Nitrate, an electron acceptor, delayed the acidification of the cytoplasm compartment because it represents an alternative way to reoxidize NADH. In conclusion, for the conditions of these experiments, the pH of the cytoplasm of corn root tips was not modified by the form of N absorbed; however, the pH of this compartment was affected by the form of N presented during development anaerobiosi. (author)

  10. Mathematical modeling and experimental validation of the spatial distribution of boron in the root of Arabidopsis thaliana identify high boron accumulation in the tip and predict a distinct root tip uptake function.

    Science.gov (United States)

    Shimotohno, Akie; Sotta, Naoyuki; Sato, Takafumi; De Ruvo, Micol; Marée, Athanasius F M; Grieneisen, Verônica A; Fujiwara, Toru

    2015-04-01

    Boron, an essential micronutrient, is transported in roots of Arabidopsis thaliana mainly by two different types of transporters, BORs and NIPs (nodulin26-like intrinsic proteins). Both are plasma membrane localized, but have distinct transport properties and patterns of cell type-specific accumulation with different polar localizations, which are likely to affect boron distribution. Here, we used mathematical modeling and an experimental determination to address boron distributions in the root. A computational model of the root is created at the cellular level, describing the boron transporters as observed experimentally. Boron is allowed to diffuse into roots, in cells and cell walls, and to be transported over plasma membranes, reflecting the properties of the different transporters. The model predicts that a region around the quiescent center has a higher concentration of soluble boron than other portions. To evaluate this prediction experimentally, we determined the boron distribution in roots using laser ablation-inductivity coupled plasma-mass spectrometry. The analysis indicated that the boron concentration is highest near the tip and is lower in the more proximal region of the meristem zone, similar to the pattern of soluble boron distribution predicted by the model. Our model also predicts that upward boron flux does not continuously increase from the root tip toward the mature region, indicating that boron taken up in the root tip is not efficiently transported to shoots. This suggests that root tip-absorbed boron is probably used for local root growth, and that instead it is the more mature root regions which have a greater role in transporting boron toward the shoots. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  11. Effects of irradiation with low-energy nitrogen ion injection on root tip cells of broad bean

    International Nuclear Information System (INIS)

    Huang Yaqin; Li Jinzhe; Huang Qunce

    2012-01-01

    In order to study the cytogenetic effects of low-energy nitrogen ion irradiation, broad bean seed embryo was irradiated by different doses of nitrogen ions. Micronucleus rate, mitotic index and chromosome aberration in root-tip cells were analyzed. The results showed that the injection of ions inhibited mitosis of root tip cells, interfered the normal process of mitosis, caused aberrations of chromosome structure, behavior and number. The frequency of micronucleus and chromosomal aberrations increased with the increasing radiation dosage, while mitotic index decreased. (authors)

  12. Clastogenic adaption of Vicia faba root tip meristem cells after consecutive treatments with S-phase dependent and S-phase independent agents

    International Nuclear Information System (INIS)

    Heindorff, K.; Schubert, I.; Rieger, R.; Michaelis, A.

    1987-01-01

    Pretreatment of Vicia faba root tip meristems with low doses of S-phase independent clastogens, such as X-rays or bleomycin, prior to a high (challenge) dose of S-phase dependent clastogens, such as alkylating agents (TEM, Trenimon) or the pyridazine derivative MH, led to decreased challenge treatment-induced aberration frequencies, i.e., clastogenic adaptation. Using the inverse treatment sequence bleomycin and MH proved to be able to substitute for each other in provoking clastogenic (cross) adaptation while bleomycin and alkylating agents were unable to do so. The data support the assumption of inducible cellular functions that become triggered by low clastogen doses and additionally describe some particular properties of bleomycin when used for conditioning. Bleomycin proved to be capable to exert protection independent of the agent used for challenge treatment. (author)

  13. Barley Seed Germination/Root Elongation Toxicity Test For Evaluation Of Sludge Pre-Treatment

    DEFF Research Database (Denmark)

    Eriksson, Eva; Kusk, Kresten Ole; Barrett Sørensen, Mie

    Application of sludge from wastewater treatment plants (WWTPs) on agricultural land is an approach for nutrient recycling that rise challenges due to recalcitrant and harmful pollutants. In this study we assessed the feasibility of a seed germination test to evaluate sludge ecotoxicity and compared......-treatments. Glyphosate and eco-labelled soil were used as references. Inhibition of germination of seeds exposed to the glyphosate and sludge was registered and thus germination was successfully applied for sludge ecotoxicity assessment, and using the root elongation as the end-point was both faster and more precise...... than the sprout elongation. In comparison of pre-treated raw samples and pre-treaded and subsequently digested sludge the effects of the pre-treatments were limited and hence, the anaerobic digestion in it-self gave the foremost detoxification....

  14. Micro-scale water potential gradients visualized in soil around plant root tips using microbiosensors.

    Science.gov (United States)

    Herron, Patrick M; Gage, Daniel J; Cardon, Zoe G

    2010-02-01

    Water availability and movement in soil are critical determinants of resource availability to, and interactions among, members of the soil community. However, it has been impossible to observe gradients in soil water potential empirically at millimetre spatial scales. Here we describe progress towards that goal using output from two microbial biosensors, Pantoea agglomerans BRT98/pPProGreen and Pseudomonas putida KT2442/pPProGreen, engineered with a reporter system based on the osmotically sensitive proU promoter from Escherichia coli. The proU-GFP construct in both microbiosensors produced green fluorescent protein (GFP) as a function total water potential in nonsterile soil. Controlled experiments in liquid culture showed that dramatically different microbiosensor growth rates (resulting from exposure to different salts as osmolytes) did not alter the GFP output as a function of water potential in either sensor, but P. agglomerans' GFP levels at a given water potential were strongly influenced by the type of carbon (energy) source available to the microbes. In non-sterile rhizosphere soil along Zea mays L. roots, though GFP expression was quite variable, microbiosensors reported statistically significantly more negative soil water potentials as a function of axial distance from root tips, reflecting the gradient in soil water potential hypothesized to develop during transpiration.

  15. Induction of micronuclei in maize root-tip cells and a correlation with forward mutation at the yg2 locus

    International Nuclear Information System (INIS)

    Wagner, E.D.; Plewa, M.J.

    1985-01-01

    A standard protocol for a micronucleus assay in root tips of Zea mays was developed and calibrated using 137 Cs gamma radiation, ethylmethanesulfonate (EMS), and N-ethyl-N-nitrosourea (ENU). The root tips were sampled 1,3, and 5 days after the treatment period. Primary root tips were the most responsive with the highest frequencies of micronuclei. The frequencies then decreased to control values after 3 days. By treating the same kernels for this assay and the yellow-green-2 (yg2) forward mutation assay, it was possible to analyze and compare the induction kinetics of micronuclei formation in root-tip cells and forward mutation at the yg2 locus in leaf primordial cells. Forward mutation at the yg2 locus by gamma rays, EMS, or ENU exhibited one hit kinetics. The induction of micronuclei demonstrated nonlinear kinetics with a significant increase over controls above 200 rads gamma rays, 10 mM EMS, or 250 μM ENU. The data suggest that a higher relative proportion of yg2 mutant sectors induced by ENU may be due to chromosome aberrations than those induced by gamma radiation or EMS

  16. Inhibitive effects of gamma-ray on root tip cells mitosis for different types of cultured rice

    International Nuclear Information System (INIS)

    Shen Mei; Wang Cailian; Zhao Kongnan; Xu Gang

    1988-01-01

    Studies on twelve varieties of different cultured rice showed that the mitotic indexdose relationship could be fitted by linear regression equations. The mitotic index was decreased with the increase of dose. The inhibitive effects on root tip cells mitosis were similar for different types of cultured rice but rather different from variety to variety

  17. The Arabidopsis Phosphatidylinositol Phosphate 5-Kinase PIP5K3 is a key regulator of root hair tip growth

    NARCIS (Netherlands)

    Kusano, H.; Testerink, C.; Vermeer, J.E.M.; Tsuge, T.; Shimada, H.; Oka, A.; Munnik, T.; Aoyama, T.

    2008-01-01

    Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] functions as a site-specific signal on membranes to promote cytoskeletal reorganization and membrane trafficking. Localization of PtdIns(4,5)P2 to apices of growing root hairs and pollen tubes suggests that it plays an important role in tip

  18. Changes in the proteomic and metabolic profiles of Beta vulgaris root tips in response to iron deficiency and resupply

    Directory of Open Access Journals (Sweden)

    Álvarez-Fernández Ana

    2010-06-01

    Full Text Available Abstract Background Plants grown under iron deficiency show different morphological, biochemical and physiological changes. These changes include, among others, the elicitation of different strategies to improve the acquisition of Fe from the rhizosphere, the adjustment of Fe homeostasis processes and a reorganization of carbohydrate metabolism. The application of modern techniques that allow the simultaneous and untargeted analysis of multiple proteins and metabolites can provide insight into multiple processes taking place in plants under Fe deficiency. The objective of this study was to characterize the changes induced in the root tip proteome and metabolome of sugar beet plants in response to Fe deficiency and resupply. Results Root tip extract proteome maps were obtained by 2-D isoelectric focusing polyacrylamide gel electrophoresis, and approximately 140 spots were detected. Iron deficiency resulted in changes in the relative amounts of 61 polypeptides, and 22 of them were identified by mass spectrometry (MS. Metabolites in root tip extracts were analyzed by gas chromatography-MS, and more than 300 metabolites were resolved. Out of 77 identified metabolites, 26 changed significantly with Fe deficiency. Iron deficiency induced increases in the relative amounts of proteins and metabolites associated to glycolysis, tri-carboxylic acid cycle and anaerobic respiration, confirming previous studies. Furthermore, a protein not present in Fe-sufficient roots, dimethyl-8-ribityllumazine (DMRL synthase, was present in high amounts in root tips from Fe-deficient sugar beet plants and gene transcript levels were higher in Fe-deficient root tips. Also, a marked increase in the relative amounts of the raffinose family of oligosaccharides (RFOs was observed in Fe-deficient plants, and a further increase in these compounds occurred upon short term Fe resupply. Conclusions The increases in DMRL synthase and in RFO sugars were the major changes induced by Fe

  19. Influence of gamma-rays on the ultrastructures of root tip cells of rye, maize and wheat

    International Nuclear Information System (INIS)

    Huang Chengyan; Zhao Shixu

    1987-01-01

    In this experiment, seedlings of rye, maize and wheat were exposed to gamma rays with the doses of 77.2 Gy, 144.75 Gy and 289.5 Gy and a dose rate of 1.42 Gy/min. Root tips were taken for electron microscopic studies. The results indicated that as the increase of exposures and prolongation of time after exposure, the degree of vacuolation in the root tip cells were increased up to intense vacuolation. The endoplasmic reticulum swelled gradually. Band-like and reticular vacuoles were formed from swelled endoplasmic raticulum. Endoplasmic reticulum and Golgi apparatus were responsible for the vacuolization of the cells. Nucleus changed there shapes irregularly and sometimes micronuclei could be observed. Mitochondria cristae decreased even disappeared. The matrix turned to light and outer and inner membrane broke forming disabled structures. No obvious structure damages were found on the Golgi apparatus and cell wall

  20. Cytogenetic effects of 48titanium (48ti) on meristematic cells of root tips of lens culinaris med

    International Nuclear Information System (INIS)

    Sepet, H.; Bozdag, B.

    2014-01-01

    Cytogenetic effects of 48Titanium (48Ti) on meristematic cells of root tips belonging to the plant (Lens culinaris Medik.) have been Investigated. Seeds of the plant, prepared were kept in 48Ti standart for different time period as control during 1/4, 1/2, 1, 2, 4, 8, 12, 16, 20, 24 hours. Seeds treated with 48Ti were made sprout and the root tips obtained were prepared for microscopic examination. At the end of the microscopic examinations, some abnormalities as chromosome breakings, chromosome dispersion, bridge chromosome, chromosome adherence, ring chromosome were observed. Abnormalities were seen at each treatment depended on the time periods. Variety and number of abnormality were usually seen to be increasing, depending on the increase of treatment time. The results obtained were evaluated statistically. (author)

  1. Effect of Hot water and dilute acid pretreatment on the chemical properties of liquorice root

    Directory of Open Access Journals (Sweden)

    zahra takzare

    2016-06-01

    Full Text Available Abstract In this study, the liquorice root (Glycyrrhiza glabra that was extracted in the factory in Kerman province, pre-hydrolyzed and then chemical compositions (Extractives, Lignin content, Holocellulose percent, the hydrolysis process yield and weight loss of the waste was measured. Pre-hydrolysis process was done on the above mentioned waste by hot water, hot water followed by 0.5 percent sulfuric acid and also alone sulfuric acid with different concentrations (0.5, 1, 1.5 and 2 percent The samples were pre-hydrolyzed in hot water at 150 °C and 30, 60 and 90 minutes as well as in the mixture of hot water and 0.5 % sulfuric acid at 150 °C and 60 minutes and also in pure sulfuric acid, at 130 °C and at 60 minutes. The results showed that the pre-hydrolyzed treatment with hot water in 60 minutes had been favorable performance in the respect of weight loss, lignin content and holocellulose percent. Also, in the case of pre-treatment including sulfuric acid, 2% dose can be good selected option in term of maximum holocellulose percent and minimum lignin content so that it can be suggested to produce higher value-added products such as bioethanol from licorice root bid.

  2. Heterologous Expression of Panax ginseng PgTIP1 Confers Enhanced Salt Tolerance of Soybean Cotyledon Hairy Roots, Composite, and Whole Plants

    Directory of Open Access Journals (Sweden)

    Jing An

    2017-07-01

    Full Text Available The Panax ginseng TIP gene PgTIP1 was previously demonstrated to have high water channel activity by its heterologous expression in Xenopus laevis oocytes and in yeast; it also plays a significant role in growth of PgTIP1-transgenic Arabidopsis plants under favorable conditions and has enhanced tolerance toward salt and drought treatment. In this work, we first investigated the physiological effects of heterologous PgTIP1 expression in soybean cotyledon hairy roots or composite plants mediated by Agrobacterium rhizogenes toward enhanced salt tolerance. The PgTIP1-transgenic soybean plants mediated by the pollen tube pathway, represented by the lines N and J11, were analyzed at the physiological and molecular levels for enhanced salt tolerance. The results showed that in terms of root-specific heterologous expression, the PgTIP1-transformed soybean cotyledon hairy roots or composite plants displayed superior salt tolerance compared to the empty vector-transformed ones according to the mitigatory effects of hairy root growth reduction, drop in leaf RWC, and rise in REL under salt stress. Additionally, declines in K+ content, increases in Na+ content and Na+/K+ ratios in the hairy roots, stems, or leaves were effectively alleviated by PgTIP1-transformation, particularly the stems and leaves of composite soybean plants. At the whole plant level, PgTIP1-trasgenic soybean lines were found to possess stronger root vigor, reduced root and leaf cell membrane damage, increased SOD, POD, CAT, and APX activities, steadily increased leaf Tr, RWC, and Pn values, and smaller declines in chlorophyll and carotenoid content when exposed to salt stress compared to wild type. Moreover, the distribution patterns of Na+, K+, and Cl- in the roots, stems, and leaves of salt-stressed transgenic plants were readjusted, in that the absorbed Na+ and Cl- were mainly restricted to the roots to reduce their transport to the shoots, and the transport of root-absorbed K+ to the

  3. Auxin increases the hydrogen peroxide (H2O2) concentration in tomato (Solanum lycopersicum) root tips while inhibiting root growth

    NARCIS (Netherlands)

    Ivanchenko, Maria G.; den Os, Desiree; Monshausen, Gabriele B.; Dubrovsky, Joseph G.; Bednarova, Andrea; Krishnan, Natraj

    2013-01-01

    The hormone auxin and reactive oxygen species (ROS) regulate root elongation, but the interactions between the two pathways are not well understood. The aim of this study was to investigate how auxin interacts with ROS in regulating root elongation in tomato, Solanum lycopersicum. Wild-type and

  4. Leaves are just the tip of the iceberg: A review of plant roots in Arctic tundra

    Science.gov (United States)

    Iversen, C. M.; Sloan, V. L.; Sullivan, P.; Euskirchen, E. S.; McGuire, A. D.; Norby, R. J.; Walker, A. P.; Warren, J.; Wullschleger, S. D.

    2013-12-01

    Arctic tundra is characterized by short-statured plant communities underlain by carbon (C)-rich soils and permafrost. Ecosystem C and nutrient cycles in tundra are driven by complex interactions between plants and their environment. However, rooting dynamics remain some of the least understood aspects of plant growth in the Arctic. Our goal in this review is to synthesize the available literature on arctic roots, and also their treatment in models. Belowground plant biomass in tundra ecosystems can be an order of magnitude larger than aboveground biomass. Roots are shallowly distributed, and often found in a thick organic horizon at the soil surface. Species-specific differences in root distribution, mycorrhizal colonization, and preference for different forms of nitrogen (N) may affect plant species competition and distribution under changing environmental conditions, and should be better represented in large-scale models. Future research should focus on estimates of arctic root production and lifespan, across the diversity of tundra ecosystems that exist in the Arctic. Improved linkages between root traits and easily-measured aboveground traits will facilitate the representation of roots in large-scale land surface models, and advance our understanding of the contribution of roots to ecosystem C and N cycling in the Arctic under current and future climates.

  5. Salicylic acid alleviates cadmium-induced stress responses through the inhibition of Cd-induced auxin-mediated reactive oxygen species production in barley root tips.

    Science.gov (United States)

    Tamás, Ladislav; Mistrík, Igor; Alemayehu, Aster; Zelinová, Veronika; Bočová, Beáta; Huttová, Jana

    2015-01-15

    Auxin is a master regulator of root growth by modulating its development under the constantly changing environment. Recently, an antagonistic interaction was suggested between SA and IAA signaling. Therefore, the purpose of this work was to analyze and compare the effect of the indole-3-acetic acid (IAA) signaling inhibitor p-chlorophenoxyisobutyric acid (PCIB) and salicylic acid (SA) as a potential IAA signaling inhibitor on the root growth, enzyme activity and reactive oxygen species (ROS) production in Cd- and IAA-treated barley root tips. Exposure of plants to Cd resulted in a more than threefold increase of IAA content in the root apex even 3h after the treatment. In addition, exogenously applied IAA evoked root responses such as root growth inhibition and swelling, ROS generation and activation of lipoxygenase or glutathione peroxidase identical to those induced by Cd. Furthermore, both Cd- and IAA-induced stress responses were markedly reversed by PCIB or SA post-treatment. Similarly to PCIB, SA did not affect the IAA content of root tips, suggesting the action of SA on the IAA signaling pathway in barley roots. SA probably does not alleviate the Cd toxicity in roots, but rather prevents or partially inhibits the root defense response to the presence of Cd through the inhibition of Cd-induced IAA-mediated ROS generation in roots. Copyright © 2014 Elsevier GmbH. All rights reserved.

  6. Effect of Soil pH on Growth and Cation Deposition in the Root Tip of Zea mays L.

    Science.gov (United States)

    Walter; Silk; Schurr

    2000-03-01

    The effects of sandy soil pH on the distribution of growth velocities and on cation concentrations and deposition rates in root growth zones of Zea mays L. seedlings were investigated. The pH values of the rooting medium varied between 4.2 and 8.6 in sand culture (70% saturated) without external supply of nutrients. At all pH values, densities (in µmoles per g fresh weight) of potassium, magnesium, and calcium increased toward the root tip. Lower pH in the medium increased calcium tissue density fivefold and magnesium density 1.7-fold, whereas the density of potassium, the overall elongation rate, and the growth velocity distribution did not show any significant pH dependence. Throughout the growth zone the deposition rates of the divalent cations, as calculated on the basis of the continuity equation, increased with lower pH. The data are consistent with the hypothesis that the effects of pH on the cation deposition rates are due to the increase in the divalent cation concentration of the soil solution at low pH and that the abundant uronic acid residues of the young walls of the meristem provide a reservoir of storage capacity for Ca and Mg under conditions of low nutrient availability.

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

    Science.gov (United States)

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

    2016-12-05

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

  8. Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells of Allium cepa

    Directory of Open Access Journals (Sweden)

    Jigna G. Tank

    2014-01-01

    Full Text Available Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

  9. Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells of Allium cepa

    Science.gov (United States)

    Tank, Jigna G.; Thaker, Vrinda S.

    2014-01-01

    Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed. PMID:24955358

  10. Induction of micronuclei in the root tip cells of Haplopappus germinating seeds by fission neutrons and X rays

    Energy Technology Data Exchange (ETDEWEB)

    Hanmoto, Hidehiro; Yonezawa, Yoshihiko (Naruto Univ. of Education, Tokushima (Japan)); Itoh, Tetsuo; Kondo, Sohei

    1992-12-01

    Seeds of Haplopappus gracilis (2n=4), an annual Compositae, were soaked in water for 24 hr and then irradiated with fission neutrons from the 1-wattage reactor, UTR-KINKI, or X rays. The root tip cells were inspected at 48 hr post-irradiation for evidence of chromosome damage using micronucleus as endpoint. The frequency of neutron-induced micronuclei increased almost linearly as the dose increased up to as much as 1.2 Gy. X-ray-induced micronuclei showed an exponential dose-response relation. From dose-response data, we estimated that the dose necessary to induce micronuclei at a frequency of 5 per 1,000 cells was 1.2 Gy for neutrons and 8.6 Gy for X rays. Thus, to induce chromosome damage in the somatic cells of germinating Haplopappus seeds, fission neutrons were much more effective than X rays. (author).

  11. Cell wall pectin methyl-esterification and organic acids of root tips involve in aluminum tolerance in Camellia sinensis.

    Science.gov (United States)

    Li, Dongqin; Shu, Zaifa; Ye, Xiaoli; Zhu, Jiaojiao; Pan, Junting; Wang, Weidong; Chang, Pinpin; Cui, Chuanlei; Shen, Jiazhi; Fang, Wanping; Zhu, Xujun; Wang, Yuhua

    2017-10-01

    Tea plant (Camellia sinensis (O.) Kuntze) can survive from high levels of aluminum (Al) in strongly acidic soils. However, the mechanism driving its tolerance to Al, the predominant factor limiting plant growth in acid condition, is still not fully understood. Here, two-year-old rooted cuttings of C. sinensis cultivar 'Longjingchangye' were used for Al resistance experiments. We found that the tea plants grew better in the presence of 0.4 mM Al than those grew under lower concentration of Al treatments (0 and 0.1 mM) as well as higher levels treatment (2 and 4 mM), confirming that appropriate Al increased tea plant growth. Hematoxylin staining assay showed that the apical region was the main accumulator in tea plant root. Subsequently, immunolocalization of pectins in the root tip cell wall showed a rise in low-methyl-ester pectin levels and a reduction of high-methyl-ester pectin content with the increasing Al concentration of treatments. Furthermore, we observed the increased expressions of C. sinensis pectin methylesterase (CsPME) genes along with the increasing de-esterified pectin levels during response to Al treatments. Additionally, the levels of organic acids increased steadily after treatment with 0.1, 0.4 or 2 mM Al, while they dropped after treatment with 4 mM Al. The organic acids secretion from root followed a similar trend. Similarly, a gradual increase in malate dehydrogenase (MDH), citrate synthase (CS) and glycolate oxidase (GO) enzyme activities and relevant metabolic genes expression were detected after the treatment of 0.1, 0.4 or 2 mM Al, while a sharp decrease was resulted from treatment with 4 mM Al. These results confirm that both pectin methylesterases and organic acids contribute to Al tolerance in C. sinensis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Effects of polyamines and polyamine biosynthetic inhibitors on mitotic activity of Allium cepa root tips.

    Science.gov (United States)

    Unal, Meral; Palavan-Unsal, Narcin; Tufekci, M A

    2008-03-01

    The genotoxic and cytotoxic effects of exogenous polyamines (PAs), putrescine (Put), spermidine (Spd), spermine (Spm) and PA biosynthetic inhibitors, alpha-difluoromethylornithine (DFMO), cyclohexilamine (CHA), methylglioxal bis-(guanylhydrazone) (MGBG) were investigated in the root meristems of Allium cepa L. The reduction of mitotic index and the induction of chromosomal aberrations such as bridges, stickiness, c-mitotic anaphases, micronuclei, endoredupliction by PAs and PA biosynthetic inhibitors were observed and these were used as evidence of genotoxicity and cytotoxicity.

  13. Effects of long exposure to spent potliner on seeds, root tips, and meristematic cells of Allium cepa L.

    Science.gov (United States)

    Andrade-Vieira, Larissa Fonseca; Palmieri, Marcel José; Davide, Lisete Chamma

    2017-09-07

    Spent potliner (SPL) is a solid waste generated in the aluminum mining and processing industry. It is sometimes dumped into the environment and leach in contact with water, thereupon affecting living beings, which are likely to be exposed to the waste for long periods. Considering this, we aimed to evaluate the effects of extended exposure to SPL through bioassays using Allium cepa as plant model system. Seeds of A. cepa were either directly exposed to SPL (continuous exposure) or first germinated in water and then exposed to SPL (discontinuous exposure). The germination rate was determined from 24 to 192 h of exposure. The maximum effects of SPL on germination were observed after 96 h in both exposure approaches. For the parameter root elongation, the discontinuous treatment was more efficient in demonstrating differences among the applied SPL concentrations (60% of reduction). Microscopic analysis was carried out in root tip cells discontinuously exposed to SPL for 96 h. A mitodepressive effect was observed (above 50%), as well as increased rate of chromosome abnormalities (up to 100-fold) and induction of cell death. The consequences of exposure to SPL for longer periods are discussed.

  14. AtNIGT1/HRS1 integrates nitrate and phosphate signals at the Arabidopsis root tip.

    Science.gov (United States)

    Medici, Anna; Marshall-Colon, Amy; Ronzier, Elsa; Szponarski, Wojciech; Wang, Rongchen; Gojon, Alain; Crawford, Nigel M; Ruffel, Sandrine; Coruzzi, Gloria M; Krouk, Gabriel

    2015-02-27

    Nitrogen and phosphorus are among the most widely used fertilizers worldwide. Nitrate (NO3(-)) and phosphate (PO4(3-)) are also signalling molecules whose respective transduction pathways are being intensively studied. However, plants are continuously challenged with combined nutritional deficiencies, yet very little is known about how these signalling pathways are integrated. Here we report the identification of a highly NO3(-)-inducible NRT1.1-controlled GARP transcription factor, HRS1, document its genome-wide transcriptional targets, and validate its cis-regulatory elements. We demonstrate that this transcription factor and a close homologue repress the primary root growth in response to P deficiency conditions, but only when NO3(-) is present. This system defines a molecular logic gate integrating P and N signals. We propose that NO3(-) and P signalling converge via double transcriptional and post-transcriptional control of the same protein, HRS1.

  15. Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-Temperature Season

    Directory of Open Access Journals (Sweden)

    Jin eSun

    2016-03-01

    Full Text Available Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C and exogenous spermidine (Spd root-pretreatment (SRP, 0.1 mM on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (Gs to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII, rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved PN of lettuce plants in a high-temperature season by both improvement of Gs to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation.

  16. Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-temperature Season.

    Science.gov (United States)

    Sun, Jin; Lu, Na; Xu, Hongjia; Maruo, Toru; Guo, Shirong

    2016-01-01

    Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C) and exogenous spermidine (Spd) root-pretreatment (SRP, 0.1 mM) on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C) were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (G s) to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII), rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved P N of lettuce plants in a high-temperature season by both improvement of G s to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation.

  17. Spatial-temporal analysis of polyethylene glycol-reduced aluminium accumulation and xyloglucan endotransglucosylase action in root tips of common bean (Phaseolus vulgaris).

    Science.gov (United States)

    Zhang, Maolin; Ma, Yanqi; Horst, Walter J; Yang, Zhong-Bao

    2016-07-01

    Aluminium (Al) toxicity and drought are two major limiting factors for common bean (Phaseolus vulgaris) production on tropical acid soils. Polyethylene glycol (PEG 6000)-induced osmotic stress (OS) simulating drought stress reduces Al accumulation in the entire root tips of common bean by alteration of cell-wall (CW) porosity, which might be regulated by two genes encoding xyloglucan endotransglucosylase/hydrolase, PvXTH9 and PvXTHb The aim of this research was to understand the spatial and temporal regulation of both XTH genes in PEG-mediated Al accumulation in the root tips. In this study the spatial and temporal expression patterns of Al-inhibited root elongation, Al accumulation, XTH gene expression and xyloglucan endotransglucosylase (XET) enzyme action in the root tips were analysed under PEG-induced OS by a combination of physiological and molecular approaches such as quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and in situ fluorescence detection of XET in root tips. The results showed that Al accumulation, expression of XTH genes and XET action were distinctly reduced in the apical 0-2, 2-7 and 7-12 mm zones under OS, implying a potential regulatory role of XTH genes and XET enzyme in CW Al accumulation in these zones. The results provide novel insights into the physiological and molecular mechanisms of CW structure modification as a response of plant roots to OS, which will contribute to mitigate Al and drought stresses, severely limiting crop yields on acid soils. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Novel roles of hydrogen peroxide (H₂O₂) in regulating pectin synthesis and demethylesterification in the cell wall of rice (Oryza sativa) root tips.

    Science.gov (United States)

    Xiong, Jie; Yang, Yongjie; Fu, Guanfu; Tao, Longxing

    2015-04-01

    Hydrogen peroxide (H₂O₂) has been reported to increase lignin formation, enhance cell wall rigidification, restrict cell expansion and inhibit root elongation. However, our results showed that it not only inhibited rice (Oryza sativa) root elongation, but also increased root diameter. No study has reported how and why H₂O₂ increases cell expansion and root diameter. Exogenous H₂O₂ and its scavenger 4-hydroxy-Tempo were applied to confirm the roles of H₂O₂. Immunofluorescence, fluorescence probe, ruthenium red staining, histological section and spectrophotometry were used to monitor changes in the degree of pectin methylesterification, pectin content, pectin methylesterase (PME) activity and H₂O₂ content. Exogenous H₂O₂ inhibited root elongation, but increased cell expansion and root diameter significantly. H₂O₂ not only increased the region of pectin synthesis and pectin content in root tips, but also increased PME activity and pectin demethylesterification. The scavenger 4-hydroxy-Tempo reduced root H₂O₂ content and recovered H₂O₂-induced increases in cell expansion and root diameter by inhibiting pectin synthesis, PME activity and pectin demethylesterification. H₂O₂ plays a novel role in the regulation of pectin synthesis, PME activity and pectin demethylesterification. H₂O₂ increases cell expansion and root diameter by increasing pectin content and demethylesterification. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  19. Wake development behind paired wings with tip and root trailing vortices: consequences for animal flight force estimates.

    Science.gov (United States)

    Horstmann, Jan T; Henningsson, Per; Thomas, Adrian L R; Bomphrey, Richard J

    2014-01-01

    Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV) of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body), angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals.

  20. Wake development behind paired wings with tip and root trailing vortices: consequences for animal flight force estimates.

    Directory of Open Access Journals (Sweden)

    Jan T Horstmann

    Full Text Available Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body, angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals.

  1. Ability of Allium cepa L. root tips and Tradescantia pallida var. purpurea in N-nitrosodiethylamine genotoxicity and mutagenicity evaluation

    Directory of Open Access Journals (Sweden)

    Claudia R. de Rainho

    2010-12-01

    Full Text Available N-nitroso compounds, such as N-nitrosodiethylamine (NDEA, can be formed by the reaction of secundary amines with nitrosating agents, and are suspected to be involved in tumors in humans. NDEA has been considered a weak carcinogen in genotoxic assays probably due to the inefficient nitrosamine activation system that is used and/or to the efficient repair system. In this work, we evaluated the sensibility of Allium cepa L. root tips and Tradescantia stamen hair mutation assay (Trad-SH using Tradescantia pallida var. purpurea for NDEA (0.1; 0.5; 5 and 25mM genotoxicity and mutagenicity induction. Allium cepa L. was treated with different NDEA concentrations for 3h, for 3 consecutive days, including negative control (distilled water and positive control maleic hydrazide (MH 30mg/mL. After treatment, the roots were hydrolyzed, squashed, and the mitotic index (MI and cytological abnormalities were scored. The results revealed a cytostatic effect of NDEA (0.5 and 5mM, showing a significant reduction in the MI. Chromosome stickiness suggests a NDEA toxic effect. T. pallida purpurea did not respond to mutagens with a dose-dependent pattern. In conclusion, our study indicates that the root tips of Allium cepa L. have sensibility to detect NDEA genotoxicity, but not for Trad-SH test.Nitrocompostos, como N-nitrosodietilamina (NDEA, podem ser formados pela reação entre uma amina secundária e agentes nitrosantes e são suspeitos de estarem envolvidos na formação de tumores em humanos. NDEA é considerada um carcinógeno fraco e ensaios genotóxicos provavelente pela utilização de um sistema de ativação ineficiente e/ou pela utilização de um eficiente sistema de reparo. Neste trabalho, nós avaliamos a sensibilidade de ensaios com Alliu cepa L. e Tradescantia pallida var. purpurea (Trad-SH à genotoxicidade e mutagenicidade induzidas por diferentes concentrações de NDEA (0,1; 0,5; 5 e 25mM por 3h, por 3 dias consecutivos, incluindo controle

  2. [Influence of Four Kinds of PPCPs on Micronucleus Rate of the Root-Tip Cells of Vicia-faba and Garlic].

    Science.gov (United States)

    Wang, Lan-jun; Wang, Jin-hua; Zhu, Lu-sheng; Wang, Jun; Zhao, Xiang

    2016-04-15

    In order to determine the degree of biological genetic injury induced by PPCPs, the genotoxic effects of the doxycycline (DOX), ciprofloxacin (CIP), triclocarban (TCC) and carbamazepine (CBZ) in the concentration range of 12.5-100 mg · L⁻¹ were studied using micronucleus rate and micronucleus index of Vicia-fabe and garlic. The results showed that: (1) When the Vicia-faba root- tip cells were exposed to DOX, CIP, TCC and CBZ, micronucleus rates were higher than 1.67 ‰ (CK₁), it was significantly different from that of the control group (P garlic root tip cells were exposed to DOX, CIP, TCC and CBZ respectively, the micronucleus rates were less than those of the Vicia-faba, while in most treatments significantly higher than that of the control group (0.67‰). The micronucleus index was higher than 3.5 in the groups exposed to CIP with concentrations of 25, 50, 100 mg · L⁻¹ and TCC and CBZ with concentrations of 25 mg · L⁻¹; With the increase of exposure concentrations, the micronucleus rate showed a trend of first increasing and then decreasing as well. (3) Under the same experimental conditions, the cells micronucleus rates of the garlic cells caused by the four tested compounds were significantly lower than those of Vicia-faba. (4) The micronucleus index of the root tip cells of Vicia-faba and garlic treated with the four kinds of compounds followed the order of CIP > CBZ > TCC > DOX. These results demonstrated that the four compounds caused biological genetic injury to root-tip cells of Vicia-faba and garlic, and the genetic damage caused to garlic was significantly lower than that to Vicia-faba. The damages caused by the four kinds of different compounds were also different.

  3. Comparison of the Distances between the Maxillary Sinus Floor and Root-Tips of the First and Second Maxillary Molar Teeth Using Panoramic Radiography among Dolichocephalic and Brachycephalic and Mesocephalic Individuals

    Directory of Open Access Journals (Sweden)

    Hamidreza Arabion

    2015-06-01

    Full Text Available Introduction: Comparison of the relationships and distance between maxillary root tips and   the maxillary sinus floor using oral panoramic in the dolichocephalic and brachycephalic compared to mesocephalic individuals. Methods: Oral panoramic images from 300 individuals were analyzed and the relationships and distance between the maxillary root tips and the sinus floor was assessed by qualitative and quantitative variables. Results: The distance was significantly higher in the brachycephalic groups than that of the mesocephalic, and the mesocephalic group showed longer distance in comparison to dolichocephalic individuals. Qualitative comparison showed that type 1 relationship was the dominant position in the brachycephalic individuals while most of dolichocephalic individuals demonstrated type 2 and 3 relationships of the molar root tips and the maxillary sinus floor. Conclusion: Higher distances between the molar root tips and the maxillary sinus floor could be expected in the brachycephalic than mesocephalic and dolichocephalic individuals

  4. Sealing ability of three root-end filling materials prepared using an erbium: Yttrium aluminium garnet laser and endosonic tip evaluated by confocal laser scanning microscopy

    Science.gov (United States)

    Nanjappa, A Salin; Ponnappa, KC; Nanjamma, KK; Ponappa, MC; Girish, Sabari; Nitin, Anita

    2015-01-01

    Aims: (1) To compare the sealing ability of mineral trioxide aggregate (MTA), Biodentine, and Chitra-calcium phosphate cement (CPC) when used as root-end filling, evaluated under confocal laser scanning microscope using Rhodamine B dye. (2) To evaluate effect of ultrasonic retroprep tip and an erbium:yttrium aluminium garnet (Er:YAG) laser on the integrity of three different root-end filling materials. Materials and Methods: The root canals of 80 extracted teeth were instrumented and obturated with gutta-percha. The apical 3 mm of each tooth was resected and 3 mm root-end preparation was made using ultrasonic tip (n = 30) and Er:YAG laser (n = 30). MTA, Biodentine, and Chitra-CPC were used to restore 10 teeth each. The samples were coated with varnish and after drying, they were immersed in Rhodamine B dye for 24 h. The teeth were then rinsed, sectioned longitudinally, and observed under confocal laser scanning microscope. Statistical Analysis Used: Data were analyzed using one-way analysis of variance (ANOVA) and a post-hoc Tukey's test at P < 0.05 (R software version 3.1.0). Results: Comparison of microleakage showed maximum peak value of 0.45 mm for Biodentine, 0.85 mm for MTA, and 1.05 mm for Chitra-CPC. The amount of dye penetration was found to be lesser in root ends prepared using Er:YAG laser when compared with ultrasonics, the difference was found to be statistically significant (P < 0.05). Conclusions: Root-end cavities prepared with Er:YAG laser and restored with Biodentine showed superior sealing ability compared to those prepared with ultrasonics. PMID:26180420

  5. A 3D digital atlas of the Nicotiana tabacum root tip and its use to investigate changes in the root apical meristem induced by the Agrobacterium 6b oncogene.

    Science.gov (United States)

    Pasternak, Taras; Haser, Thomas; Falk, Thorsten; Ronneberger, Olaf; Palme, Klaus; Otten, Léon

    2017-10-01

    Using the intrinsic Root Coordinate System (iRoCS) Toolbox, a digital atlas at cellular resolution has been constructed for Nicotiana tabacum roots. Mitotic cells and cells labeled for DNA replication with 5-ethynyl-2'-deoxyuridine (EdU) were mapped. The results demonstrate that iRoCS analysis can be applied to roots that are thicker than those of Arabidopsis thaliana without histological sectioning. A three-dimensional (3-D) analysis of the root tip showed that tobacco roots undergo several irregular periclinal and tangential divisions. Irrespective of cell type, rapid cell elongation starts at the same distance from the quiescent center, however, boundaries between cell proliferation and transition domains are cell-type specific. The data support the existence of a transition domain in tobacco roots. Cell endoreduplication starts in the transition domain and continues into the elongation zone. The tobacco root map was subsequently used to analyse root organization changes caused by the inducible expression of the Agrobacterium 6b oncogene. In tobacco roots that express the 6b gene, the root apical meristem was shorter and radial cell growth was reduced, but the mitotic and DNA replication indexes were not affected. The epidermis of 6b-expressing roots produced less files and underwent abnormal periclinal divisions. The periclinal division leading to mature endodermis and cortex3 cell files was delayed. These findings define additional targets for future studies on the mode of action of the Agrobacterium 6b oncogene. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  6. Apical pressure and extent of irrigant flow beyond the needle tip during positive-pressure irrigation in an in vitro root canal model.

    Science.gov (United States)

    Park, Ellen; Shen, Ya; Khakpour, Mehrzad; Haapasalo, Markus

    2013-04-01

    This study aimed to measure the pressure generated during positive-pressure irrigation at the periapex of an in vitro tooth model using a novel method of measurement, investigating the effect of flow rate and needle design. Apical pressure was correlated with the extent of dye clearance from the end of a needle tip in a plastic root canal model with similar dimensions. The mesiobuccal canal of a mandibular molar was instrumented to #35/06 and placed into a chamber coupled to a pressure transducer. Irrigation was performed using a digital peristaltic pump using flow rates from 1-15 mL/min with irrigation needles of different sizes and designs. A plastic root canal model instrumented to the same size filled with dye was used to measure the extent of dye clearance beyond the needle tip using the same irrigation conditions. Positive-pressure irrigation revealed a flow rate-dependent increase in apical pressure (P irrigation flow rates was several times higher than at low flow rates. Needle designs with safety features yielded statistically significant lower apical pressures than needles without safety features (P model at flow rates higher than 4 mL/min. If apical clearance of dye beyond the needle tip is a measure of irrigation effectiveness, then maximum effectiveness with safe apical pressures can be gained at specific flow rates using specific needle tip designs. The use of an irrigation flow rate of 4 mL/min was able to achieve maximum effectiveness in this study. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Laser activation of endodontic irrigants with improved conical laser fiber tips for removing smear layer in the apical third of the root canal.

    Science.gov (United States)

    George, Roy; Meyers, Ian A; Walsh, Laurence J

    2008-12-01

    With a tube etching process, conical-ended optical fibers for middle infrared lasers that have lateral emissions can be produced, a feature of benefit for delivering laser energy onto the root canal walls. This study examined the ability of these improved laser tips when Er:YAG and Er,Cr:YSGG lasers were used in root canals in which thick smear layers had been created intentionally to provide a challenge for the laser system. Smear layer was assessed from scanning electron microscopy images with an objective digital method. Lasing improved the action of ethylene diamine tetraacetic acid with cetavlon (EDTAC) in removing smear layer. Conical fibers performed better than plain fibers, but there was no difference in performance between the 2 laser systems when matched for all other parameters. These results provide a "proof of concept" for lateral emitting fibers for endodontic procedures and illustrate the novel contribution of lasing to the action of EDTAC in dissolving smear layer.

  8. Analysis of initial changes in the proteins of soybean root tip under flooding stress using gel-free and gel-based proteomic techniques.

    Science.gov (United States)

    Yin, Xiaojian; Sakata, Katsumi; Nanjo, Yohei; Komatsu, Setsuko

    2014-06-25

    Flooding has a severe negative effect on soybean cultivation in the early stages of growth. To obtain a better understanding of the response mechanisms of soybean to flooding stress, initial changes in root tip proteins under flooding were analyzed using two proteomic techniques. Two-day-old soybeans were treated with flooding for 3, 6, 12, and 24h. The weight of soybeans increased during the first 3h of flooding, but root elongation was not observed. Using gel-based and gel-free proteomic techniques, 115 proteins were identified in root tips, of which 9 proteins were commonly detected by both methods. The 71 proteins identified by the gel-free proteomics were analyzed by a hierarchical clustering method based on induction levels during the flooding, and the proteins were divided into 5 clusters. Additional interaction analysis of the proteins revealed that ten proteins belonging to cluster I formed the center of a protein interaction network. mRNA expression analysis of these ten proteins showed that citrate lyase and heat shock protein 70 were down-regulated, whereas calreticulin was up-regulated in initial phase of flooding. These results suggest that flooding stress to soybean induces calcium-related signal transduction, which might play important roles in the early responses to flooding. Flooding has a severe negative effect on soybean cultivation, particularly in the early stages of growth. To better understand the response mechanisms of soybean to the early stages of flooding stress, two proteomic techniques were used. Two-day-old soybeans were treated without or with flooding for 3, 6, 12, and 24h. The fresh weight of soybeans increased during the first 3h of flooding stress, but the growth then slowed and no root elongation was observed. Using gel-based and gel-free proteomic techniques, 115 proteins were identified in root tips, of which 9 proteins were commonly detected by both methods. The 71 proteins identified by the gel-free proteomics were analyzed

  9. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    Science.gov (United States)

    George, Roy; Walsh, Laurence J

    2010-04-01

    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  10. Methods for root effects, tip effects and extending the angle of attack range to {+-} 180 deg., with application to aerodynamics for blades on wind turbines and propellers

    Energy Technology Data Exchange (ETDEWEB)

    Montgomerie, Bjoern

    2004-06-01

    For wind turbine and propeller performance calculations aerodynamic data, valid for several radial stations along the blade, are used. For wind turbines the data must be valid for the 360 degree angle of attack range. The reason is that all kinds of abnormal conditions must be analysed especially during the design of the turbine. Frequently aerodynamic data are available from wind tunnel tests where the angle of attack range is from say -5 to +20 degrees. This report describes a method to extend such data to be valid for {+-} 180 degrees. Previously the extension of data has been very approximate following the whim of the moment with the analyst. Furthermore, the Himmelskamp effect at the root and tip effects are treated in the complete method.

  11. Micronucleus test of varying amounts of potassium bromate (KBrO3) on the meristematic cells of Allium cepa var. aggregatum root tips

    International Nuclear Information System (INIS)

    Cajigal Romnick, M.; Somera, Leomerto A.

    1999-03-01

    Four hundred twenty onion bulbs of the multiplier variety Allium cepa var. aggregatum were used as test materials to assay the micronucleus induction capacity of potassium bromate doses of 0, 5, 10, 25, 50, 75, and 100 parts per million. Microscopic analyses were done using onion root tips prepared according to a modified technique of Medina (1994). These analyses were done on root tips taken from onions grown in KBrO 3 for three days and for five days. The study was conducted following a completely randomized design and the data were statistically analyzed using a non-parametric equivalent of the analysis of variance. A significant amount of micronucleated cells (MCN) were found among treated onions compared with the almost non-occurrence in the control groups (0 ppm). The Kruskal-Wallis H-test and the Wilcoxon two-samples tests revealed significant differences among treatment means and that a significant increase in the number of MCN occurs as the dose of KBr0 3 increased in both day experiments. Results from the higher doses of 50, 75, and 100 ppm were found to be significantly the same for the day 3 experiments while those of the day 5 higher doses are characterized by lack of clear cellular and nuclear outline such that scoring is difficult. Differences in MCN averages for the day 3 and 5 experiments appear to be insignificant. However, day 3 results show averages that are more significantly different from each other. These prove that the MCN can be used as an efficient and time-saving parameter for the allium test of chemicals with chromosome breaking capacities. (Author)

  12. On the relationship between endoreduplication and collet hair initiation and tip growth, as determined using six Arabidopsis thaliana root-hair mutants.

    Science.gov (United States)

    Sliwinska, Elwira; Mathur, Jaideep; Bewley, J Derek

    2015-06-01

    A positive correlation between nuclear DNA content and cell size, as postulated by the karyoplasmic theory, has been confirmed in many plant tissues. However, there is also evidence suggesting that there are exceptions. While in previous reports the cell size:ploidy relationship was studied in intact tissues containing cells of different sizes, here simultaneously developing single cells of collet hairs were used to study endoreduplication in Arabidopsis thaliana mutants that produce hairs of variable size and morphology. Endoreduplication in the root and collet zones of six different root-hair mutants was analysed before and after collet hair development using flow cytometry and confocal microscopy. Additionally, the changes in nuclear size (ploidy), shape, and movement in developing collet hairs of a hybrid between Arabidopsis transgenic line NLS-GFP-GUS and the rhd3 (root hair defective3) mutant were followed using time-lapse confocal microscopy. In this hybrid endoreduplication in the collet hairs was disturbed. However, based on the analyses of all mutants, no correlation was found between hair length and the ploidy of the cells in the collet and root regions. The results indicate that the karyoplasmic ratio is maintained at the beginning of collet-hair development, but tip growth proceeds in a DNA-amount-independent manner. The final size of a collet hair appears to be dependent more on genetic modifiers governing general cell physiology than on its DNA content. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Remembering tips

    Science.gov (United States)

    Memory aids; Alzheimer disease - remembering tips; Early memory loss - remembering tips; Dementia - remembering tips ... active: Read a lot if you have trouble remembering words. Keep a dictionary close by. Take part ...

  14. Tips for TIPS

    NARCIS (Netherlands)

    Cuijpers, C.F.

    2015-01-01

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

  15. Investigation on the effects of guava (Psidium guajava L. infusions on germination, root tips and meristematic cells of Latuca sativa

    Directory of Open Access Journals (Sweden)

    Jaquelini Luber

    2015-06-01

    Full Text Available Guava (Psidium guajava L. is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa ("purple" - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L-1 prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic effect was significant. Therefore, guava should not be used indiscriminately in popular medicine.

  16. Investigation on the effects of guava (Psidium guajava L.) infusions on germination, root tips and meristematic cells of Latuca sativa.

    Science.gov (United States)

    Luber, Jaquelini; Palmieri, Marcel J; Botelho, Carolina M; Rinaldo, Daniel; Andrade-Vieira, Larissa F

    2015-01-01

    Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa ("purple") - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L(-1)) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic effect was significant. Therefore, guava should not be used indiscriminately in popular medicine.

  17. Magnet pole tips

    Science.gov (United States)

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

    1984-04-24

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

  18. Defining multiple, distinct, and shared spatiotemporal patterns of DNA replication and endoreduplication from 3D image analysis of developing maize (Zea mays L.) root tip nuclei.

    Science.gov (United States)

    Bass, Hank W; Hoffman, Gregg G; Lee, Tae-Jin; Wear, Emily E; Joseph, Stacey R; Allen, George C; Hanley-Bowdoin, Linda; Thompson, William F

    2015-11-01

    Spatiotemporal patterns of DNA replication have been described for yeast and many types of cultured animal cells, frequently after cell cycle arrest to aid in synchronization. However, patterns of DNA replication in nuclei from plants or naturally developing organs remain largely uncharacterized. Here we report findings from 3D quantitative analysis of DNA replication and endoreduplication in nuclei from pulse-labeled developing maize root tips. In both early and middle S phase nuclei, flow-sorted on the basis of DNA content, replicative labeling was widely distributed across euchromatic regions of the nucleoplasm. We did not observe the perinuclear or perinucleolar replicative labeling patterns characteristic of middle S phase in mammals. Instead, the early versus middle S phase patterns in maize could be distinguished cytologically by correlating two quantitative, continuous variables, replicative labeling and DAPI staining. Early S nuclei exhibited widely distributed euchromatic labeling preferentially localized to regions with weak DAPI signals. Middle S nuclei also exhibited widely distributed euchromatic labeling, but the label was preferentially localized to regions with strong DAPI signals. Highly condensed heterochromatin, including knobs, replicated during late S phase as previously reported. Similar spatiotemporal replication patterns were observed for both mitotic and endocycling maize nuclei. These results revealed that maize euchromatin exists as an intermingled mixture of two components distinguished by their condensation state and replication timing. These different patterns might reflect a previously described genome organization pattern, with "gene islands" mostly replicating during early S phase followed by most of the intergenic repetitive regions replicating during middle S phase.

  19. Tipping Point

    Medline Plus

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

  20. Effects of Maytenus ilicifolia Mart. and Bauhinia candicans Benth infusions on onion root-tip and rat bone-marrow cells

    Directory of Open Access Journals (Sweden)

    Marjori Leiva Camparoto

    2002-01-01

    Full Text Available Medicinal plants are widely used to treat various diseases, and in Brazil the plants Maytenus ilicifolia Mart. and Bauhinia candicans Benth are commonly used in popular medicine. However, there are a large number of compounds in plants which can produce alterations in genetic material, and this study was conducted to investigate any possible mutagenic and cytotoxic effects that M. ilicifolia and B. candicans infusions may have on the cell cycle and chromosomes. Infusions were prepared with in natura leaves to give two concentrations of infusions, one at the concentration normally used by the population in general and the other at 10 times this value (i.e. 3.5 and 35 mg/mL for M. ilicifolia and 0.465 and 4.65 mg/mL for B. candicans. Onion (Allium cepa L. root-tip cells (RTC and Wistar rat bone-marrow cells (BMC were used as test systems in in vivo assays. The M. ilicifolia infusions at both concentrations, and the B. candicans infusion at the lower concentration, had no statistically significant depressive mitotic effect on RTC. A statistically significant depressive mitotic effect on RTC was found with the more concentrated (4.65 mg/mL B. candicans infusion as compared with a negative control. In BMC, infusions of B. candicans and M. ilicifolia produced no statistically significant increase in the number of chromosome alterations or rates of cell division as compared to controls. The significance of these findings are discussed in the light of the use of these plants as therapeutic agents.

  1. 45S rDNA regions are chromosome fragile sites expressed as gaps in vitro on metaphase chromosomes of root-tip meristematic cells in Lolium spp.

    Directory of Open Access Journals (Sweden)

    Jing Huang

    Full Text Available BACKGROUND: In humans, chromosome fragile sites are regions that are especially prone to forming non-staining gaps, constrictions or breaks in one or both of the chromatids on metaphase chromosomes either spontaneously or following partial inhibition of DNA synthesis and have been well identified. So far, no plant chromosome fragile sites similar to those in human chromosomes have been reported. METHODS AND RESULTS: During the course of cytological mapping of rDNA on ryegrass chromosomes, we found that the number of chromosomes plus chromosome fragments was often more than the expected 14 in most cells for Lolium perenne L. cv. Player by close cytological examination using a routine chromosome preparation procedure. Further fluorescent in situ hybridization (FISH using 45S rDNA as a probe indicated that the root-tip cells having more than a 14-chromosome plus chromosome fragment count were a result of chromosome breakage or gap formation in vitro (referred to as chromosome lesions at 45S rDNA sites, and 86% of the cells exhibited chromosome breaks or gaps and all occurred at the sites of 45S rDNA in Lolium perenne L. cv. Player, as well as in L. multiflorum Lam. cv. Top One. Chromatin depletion or decondensation occurred at various locations within the 45S rDNA regions, suggesting heterogeneity of lesions of 45S rDNA sites with respect to their position within the rDNA region. CONCLUSIONS: The chromosome lesions observed in this study are very similar cytologically to that of fragile sites observed in human chromosomes, and thus we conclude that the high frequency of chromosome lesions in vitro in Lolium species is the result of the expression of 45S rDNA fragile sites. Possible causes for the spontaneous expression of fragile sites and their potential biological significance are discussed.

  2. Tipping Point

    Medline Plus

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

  3. (Allium cepa) root tip mitosis

    African Journals Online (AJOL)

    Aghomotsegin

    cytogenetic approach in plant bioassays. Plant Genotoxicity 56: 177-. 184. Minissi S, Lombi E (1997). Heavy mental and mutagenic activity evaluated by Vicus faba miconucleus test, of Triber river sediments. Mutat. Res. 393:17-21. Odeigah PGC, Nurudeen O, Amund OO (1997). Genotoxicity of oil field wastewater in Nigeria ...

  4. Tipping Point

    Medline Plus

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

  5. CPAP Tips

    Medline Plus

    Full Text Available ... a continuous positive airway pressure (CPAP) device when sleeping? Here are some tips from the U.S. Food ... 395,755 views 9:28 3 Tips for Sleeping With a CPAP - Duration: 2:02. WebMD 66, ...

  6. Root Hairs

    Science.gov (United States)

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  7. Tipping Point

    Medline Plus

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

  8. CPAP Tips

    Medline Plus

    Full Text Available ... make your opinion count. Sign in Loading... Loading... Transcript The interactive transcript could not be loaded. Loading... ... Dan Uses CPAP - Duration: 4:17. Harvard Medical School 7,950 views 4:17 Tips for building ...

  9. CPAP Tips

    Science.gov (United States)

    ... make your opinion count. Sign in Loading... Loading... Transcript The interactive transcript could not be loaded. Loading... ... Dan Uses CPAP - Duration: 4:17. Harvard Medical School 7,950 views 4:17 Tips for building ...

  10. Tipping Point

    Medline Plus

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

  11. Tipping Point

    Medline Plus

    Full Text Available ... impact can kill a child or cause severe injuries. About 16,000 (mostly young children) were treated in emergency rooms for tip-over related injuries in 2006, that’s about four times more injuries ...

  12. Tipping Point

    Medline Plus

    Full Text Available ... appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch ... reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The force of ...

  13. Tipping Point

    Medline Plus

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

  14. Genotoxicity and mutagenicity of water contaminated with tannery effluents, as evaluated by the micronucleus test and comet assay using the fish Oreochromis niloticus and chromosome aberrations in onion root-tips

    Directory of Open Access Journals (Sweden)

    Silvia Tamie Matsumoto

    2006-01-01

    Full Text Available Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.

  15. The Impact of a 940 nm Diode Laser with Radial Firing Tip and Bare End Fiber Tip on Enterococcus faecalis in the Root Canal Wall Dentin of Bovine Teeth: An In Vitro Study.

    Science.gov (United States)

    Schulte-Lünzum, Ruth; Gutknecht, Norbert; Conrads, Georg; Franzen, Rene

    2017-07-01

    This in vitro study aimed to compare the bactericidal effect of two different laser delivery systems, a radial firing tip (RFT) and bare end fiber tip (BFT) used with the 940 nm diode laser on Enterococcus faecalis inoculated onto bovine radicular dentin. A total of 100 bovine dentin slices with a defined thickness of 500 and 1000 μm were prepared. They were assigned into four test groups together with untreated samples served as control for each slice thickness. The slices were inoculated on one side with 1 μL E. faecalis suspension and laser irradiation was performed indirectly on the opposite side with the 940 nm diode laser delivered with a 200 μm RFT and a BFT at 1 and 1.5 W in continuous wave mode for 8 sec per cycle and repeated four times. After irradiation, the remaining bacteria were detached and the produced suspension was diluted and plated onto blood agar plates with 5% sheep blood and incubated overnight at 37°C in a CO 2 -rich atmosphere. The colony-forming units of E. faecalis were counted and the bacterial reduction was analyzed. The diode laser equipped with RFT fiber design further reduced the number of vital E. faecalis cells significantly compared with BFT design, regardless of the used power and dentin thickness (p diode laser in conjugation with RFT showed a satisfactory bactericidal effect without any thermal side effect to the tooth-supporting tissues.

  16. Biomass pretreatment

    Science.gov (United States)

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  17. Tipping Point

    Medline Plus

    Full Text Available ... 24 hours a day. For young children whose home is a playground, it’s the best way to prevent a tip-over tragedy. Share Post Facebook Twitter ... Security, and Legal Notice | Accessibility Policy | Open Government @ CPSC | ...

  18. CPAP Tips

    Medline Plus

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

  19. Elevated CO2 and O3 effects on ectomycorrhizal fungal root tip communities in consideration of a post-agricultural soil nutrient gradient legacy

    Science.gov (United States)

    Carrie Andrew; Erik A. Lilleskov

    2014-01-01

    Despite the critical role of EMF in nutrient and carbon (C) dynamics, combined effects of global atmospheric pollutants on ectomycorrhizal fungi (EMF) are unclear. Here, we present research on EMF root-level community responses to elevated CO2 and O3. We discovered that belowground EMF community richness and similarity were...

  20. Tip enhancement

    CERN Document Server

    Kawata, Satoshi

    2007-01-01

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

  1. The effects of nano-TiO2 on seed germination, development and mitosis of root tip cells of Vicia narbonensis L. and Zea mays L

    Science.gov (United States)

    Ruffini Castiglione, Monica; Giorgetti, Lucia; Geri, Chiara; Cremonini, Roberto

    2011-06-01

    This study aimed to provide new information about phyto-toxicology of nano-TiO2 on plant systems. To contribute to the evaluation of the potential harmful effects of the nanoparticles on monocots and dicots we considered their effects on seed germination and root elongation applying a concentration range from 0.2 to 4.0‰ in the plants Zea mays L . and Vicia narbonensis L. Moreover, we achieved a genotoxicity study at cytological level in root meristems by means of traditional cytogenetic approach, to evidence possible alterations in mitotic activity, chromosomal aberrations, and micronuclei release. From these analyses it comes out that nano-TiO2 particles, after short-term exposure and under our experimental conditions, delayed germination progression for the first 24 h in both materials. Root elongation was affected only after treatment with the higher nano-TiO2 concentration. Further significant effects were detected showing mitotic index reduction and concentration-dependent increase in the aberration emergence that evidenced a nano-TiO2-induced genotoxic effect for both species.

  2. The effects of nano-TiO{sub 2} on seed germination, development and mitosis of root tip cells of Vicia narbonensis L. and Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Ruffini Castiglione, Monica, E-mail: mruffini@biologia.unipi.it [University of Pisa, Department of Biology (Italy); Giorgetti, Lucia; Geri, Chiara [Institute of Agricultural Biology and Biotechnology (IBBA/CNR), UOS Pisa (Italy); Cremonini, Roberto [University of Pisa, Department of Biology (Italy)

    2011-06-15

    This study aimed to provide new information about phyto-toxicology of nano-TiO{sub 2} on plant systems. To contribute to the evaluation of the potential harmful effects of the nanoparticles on monocots and dicots we considered their effects on seed germination and root elongation applying a concentration range from 0.2 to 4.0 Per-Mille-Sign in the plants Zea mays L. and Vicia narbonensis L. Moreover, we achieved a genotoxicity study at cytological level in root meristems by means of traditional cytogenetic approach, to evidence possible alterations in mitotic activity, chromosomal aberrations, and micronuclei release. From these analyses it comes out that nano-TiO{sub 2} particles, after short-term exposure and under our experimental conditions, delayed germination progression for the first 24 h in both materials. Root elongation was affected only after treatment with the higher nano-TiO{sub 2} concentration. Further significant effects were detected showing mitotic index reduction and concentration-dependent increase in the aberration emergence that evidenced a nano-TiO{sub 2}-induced genotoxic effect for both species.

  3. A nonsymbiotic root hair tip growth phenotype in NORK-mutated legumes: implications for nodulation factor-induced signaling and formation of a multifaceted root hair pocket for bacteria

    NARCIS (Netherlands)

    Esseling, J.J.; Lhuissier, F.G.P.; Emons, A.M.C.

    2004-01-01

    The Medicago truncatula Does not Make Infections (DMI2) mutant is mutated in the nodulation receptor-like kinase, NORK. Here, we report that NORK-mutated legumes of three species show an enhanced touch response to experimental handling, which results in a nonsymbiotic root hair phenotype. When care

  4. Automated Root Tracking with "Root System Analyzer"

    Science.gov (United States)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

  5. Genetic studies on leaf rolling and some root traits under drought ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... Root length (cm) [the length of the root from the base of the plant to the tip of the longest root], root thickness [the average diameter. (mm) of the tip portion (about 1cm from the tip) of three random secondary roots at the middle position of the root/plant], and root : shoot ratio [ratio of the root dry weight (g) to ...

  6. Prom Health and Safety Tips

    Science.gov (United States)

    ... Autumn Tips Camping Tips Family Reunions Gardening Tips Halloween Tips Healthy Halloween Prom Tips Spring Break Valentine Tips Winter Holiday ... Breast Cancer Assess Your Relationships Be Safe on Halloween Be Smoke-Free Check Alarm Batteries Know Your ...

  7. The effect of silicon on the infection by and spread of Pythium aphanidermatum in single roots of tomato and bitter gourd.

    Science.gov (United States)

    Heine, Gregor; Tikum, George; Horst, Walter J

    2007-01-01

    The effect of silicon (Si) supply on the infection and spread of Pythium aphanidermatum was studied in the roots of tomato [Lycopersicon esculentum (=Solanum lycopersicum), an Si excluder] and bitter gourd (Mormodica charantia, an Si intermediate accumulator). Individual roots were mounted into PVC compartmented boxes which allowed the application of Si and zoospores to defined root zones. Two days after inoculation, root growth was recorded, and P. aphanidermatum colonization of individual root sections was determined by ELISA. In tomato as well as in bitter gourd the root tip was the root section most sensitive to P. aphanidermatum infection. Application of Si did not affect severe root-growth inhibition by P. aphanidermatum in either species. However, continuous Si supply significantly inhibited the basipetal spread of the pathogen from the infected root apex in bitter gourd but not in tomato. Si application to the roots only during pretreatment or only during/after the infection of the roots failed to inhibit the spread of P. aphanidermatum. Determination and compartmentation of Si in the roots of bitter gourd revealed that apoplastic Si was not, but symplastic Si was, associated with the ability of the plant to reduce the spread of the fungus in roots. It is concluded that accumulation of Si in the root cell walls does not represent a physical barrier to the spread of P. aphanidermatum in bitter gourd and tomato roots. The maintenance of elevated symplastic Si contents is a prerequisite for Si-enhanced resistance against P. aphanidermatum.

  8. Tips for Daily Living

    Science.gov (United States)

    ... Tips and Gadgets for Daily Activities Dressing Tips Shopping Tips Modifying the Bathroom Driving After Stroke Medication ... and resources. Find a group in your area . Online Support If there is not a support group ...

  9. Turbine blade squealer tip rail with fence members

    Science.gov (United States)

    Little, David A

    2012-11-20

    A turbine blade includes an airfoil, a blade tip section, a squealer tip rail, and a plurality of chordally spaced fence members. The blade tip section includes a blade tip floor located at an end of the airfoil distal from the root. The blade tip floor includes a pressure side and a suction side joined together at chordally spaced apart leading and trailing edges of the airfoil. The squealer tip rail extends radially outwardly from the blade tip floor adjacent to the suction side and extends from a first location adjacent to the airfoil trailing edge to a second location adjacent to the airfoil leading edge. The fence members are located between the airfoil leading and trailing edges and extend radially outwardly from the blade tip floor and axially from the squealer tip rail toward the pressure side.

  10. Determination of the physiological root activity of fruit trees using the radioisotopes 131I

    International Nuclear Information System (INIS)

    Reckruehm, I.

    1979-01-01

    Using the radioisotope 131 I, the author made a study of the physiological root activity in a volume of soil and the activity of the individual root tips. The results show that the root activity is affected both by the size of the branch system of the crown and by the number of root tips in the given soil volume. The greater the number of branches supplied with iodine, the higher the activity of the root tips. The greater the number of root tips in a given soil volume, the lower the physiological activity of the individual root tips. (author)

  11. Healthy Vision Tips

    Science.gov (United States)

    ... for Kids >> Healthy Vision Tips Listen All About Vision About the Eye Ask a Scientist Video Series ... Links to More Information Optical Illusions Printables Healthy Vision Tips Healthy vision starts with you! Use these ...

  12. Live cell imaging of Arabidopsis root hairs

    NARCIS (Netherlands)

    Ketelaar, T.

    2014-01-01

    Root hairs are tubular extensions from the root surface that expand by tip growth. This highly focused type of cell expansion, combined with position of root hairs on the surface of the root, makes them ideal cells for microscopic observation. This chapter describes the method that is routinely used

  13. Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1989-01-01

    Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

  14. Digestive Health Tips

    Science.gov (United States)

    ... Home / Digestive Health Topic / Digestive Health Tips Digestive Health Tips Basics 10 Tips on Belching, Bloating, and Flatulence Belching is caused by swallowed air from: Eating or drinking too fast Poorly fitting dentures; not chewing food completely Carbonated beverages Chewing gum or sucking on ...

  15. Investigation of UWB Wind Turbine Blade Deflection Sensing with a Tip Antenna inside a Blade

    DEFF Research Database (Denmark)

    Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej

    2016-01-01

    An UWB blade deflection sensing system with a tip antenna inside a blade is investigated in this paper. The lower UWB band of 3.1-5.3 GHz is utilized. This system composes of two UWB radio links between one antenna inside the blade tip and two antennas outside the blade root. Blade deflections...... are tracked via two radio links using delay-based distance estimation and triangulation. In order to build reliable radio links, time-domain pulse field distributions are simulated to optimize the in-blade tip antenna polarization and the locations of the two root antennas around the root surface. Full......-blade time-domain measurements are proposed to verify the simulations and realize the blade deflection sensing with an in-blade tip antenna. With the optimized in-blade tip antenna polarization and two root antenna locations, an accuracy of 2 cm is achieved for the tip-root antenna distance estimation...

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

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Johansen, J.

    2004-01-01

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

  17. The TIPS Liquidity Premium

    DEFF Research Database (Denmark)

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

    We introduce an arbitrage-free term structure model of nominal and real yields that accounts for liquidity risk in Treasury inflation-protected securities (TIPS). The novel feature of our model is to identify liquidity risk from individual TIPS prices by accounting for the tendency that TIPS, like...... most fixed-income securities, go into buy-and-hold investors' portfolios as time passes. We find a sizable and countercyclical TIPS liquidity premium, which greatly helps our model in matching TIPS prices. Accounting for liquidity risk also improves the model's ability to forecast inflation and match...

  18. Arctic climate tipping points.

    Science.gov (United States)

    Lenton, Timothy M

    2012-02-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the Arctic are briefly reviewed. Then, the current behaviour of a range of Arctic systems is summarised. Looking ahead, a range of potential tipping phenomena are described. This leads to a revised and expanded list of potential Arctic climate tipping elements, whose likelihood is assessed, in terms of how much warming will be required to tip them. Finally, the available responses are considered, especially the prospects for avoiding Arctic climate tipping points.

  19. [Effects nutrients on the seedlings root hair development and root growth of Poncirus trifoliata under hydroponics condition].

    Science.gov (United States)

    Cao, Xiu; Xia, Ren-Xue; Zhang, De-Jian; Shu, Bo

    2013-06-01

    Ahydroponics experiment was conducted to study the effects of nutrients (N, P, K, Ca, Mg, Fe, and Mn) deficiency on the length of primary root, the number of lateral roots, and the root hair density, length, and diameter on the primary root and lateral roots of Poncirus trifoliata seedlings. Under the deficiency of each test nutrient, root hair could generate, but was mainly concentrated on the root base and fewer on the root tip. The root hair density on lateral roots was significantly larger than that on primary root, but the root hair length was in adverse. The deficiency of each test nutrient had greater effects on the growth and development of root hairs, with the root hair density on primary root varied from 55.0 to 174.3 mm(-2). As compared with the control, Ca deficiency induced the significant increase of root hair density and length on primary root, P deficiency promoted the root hair density and length on the base and middle part of primary root and on the lateral roots significantly, Fe deficiency increased the root hair density but decreased the root hair length on the tip of primary root significantly, K deficiency significantly decreased the root hair density, length, and diameter on primary root and lateral roots, whereas Mg deficiency increased the root hair length of primary root significantly. In all treatments of nutrient deficiency, the primary root had the similar growth rate, but, with the exceptions of N and Mg deficiency, the lateral roots exhibited shedding and regeneration.

  20. Nod factors alter the microtubule cytoskeleton in Medicago truncatula root hairs to allow root hair reorientation

    NARCIS (Netherlands)

    Sieberer, B.; Timmers, A.C.J.; Emons, A.M.C.

    2005-01-01

    The microtubule (MT) cytoskeleton is an important part of the tip-growth machinery in legume root hairs. Here we report the effect of Nod factor (NF) on MTs in root hairs of Medicago truncatula. In tip-growing hairs, the ones that typically curl around rhizobia, NF caused a subtle shortening of the

  1. Tips in Reading Instruction.

    Science.gov (United States)

    Ediger, Marlow

    Some tips can assist teachers in guiding each pupil to achieve more optimally, with respect to the ability to read well and reading comprehension. Among these 10 specific tips are: (1) teach individualized phonics in context; (2) assist the student to read in proper thought units by covering up words in sentences for clarification; (3) assist…

  2. ADHD: Tips to Try

    Science.gov (United States)

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

  3. Total Telephone Tips.

    Science.gov (United States)

    Corder, Lloyd E.; And Others

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

  4. The role of the distal elongation zone in the response of maize roots to auxin and gravity

    Science.gov (United States)

    Ishikawa, H.; Evans, M. L.

    1993-01-01

    We used a video digitizer system to (a) measure changes in the pattern of longitudinal surface extension in primary roots of maize (Zea mays L.) upon application and withdrawal of auxin and (b) compare these patterns during gravitropism in control roots and roots pretreated with auxin. Special attention was paid to the distal elongation zone (DEZ), arbitrarily defined as the region between the meristem and the point within the elongation zone at which the rate of elongation reaches 0.3 of the peak rate. For roots in aqueous solution, the basal limit of the DEZ is about 2.5 mm behind the tip of the root cap. Auxin suppressed elongation throughout the elongation zone, but, after 1 to 3 h, elongation resumed, primarily as a result of induction of rapid elongation in the DEZ. Withdrawal of auxin during the period of strong inhibition resulted in exceptionally rapid elongation attributable to the initiation of rapid elongation in the DEZ plus recovery in the main elongation zone. Gravistimulation of auxin-inhibited roots induced rapid elongation in the DEZ along the top of the root. This resulted in rapid gravitropism even though the elongation rate of the root was zero before gravistimulation. The results indicate that cells of the DEZ differ from cells in the bulk of the elongation zone with respect to auxin sensitivity and that DEZ cells play an important role in gravitropism.

  5. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

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

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... vs. risks? What are the limitations of TIPS? What is a Transjugular Intrahepatic Portosystemic Shunt (TIPS)? A ... likely to require a TIPS. top of page What are some common uses of the procedure? A ...

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver ... TIPS is a minimally invasive procedure that typically has a shorter recovery time than surgery. Your TIPS ...

  8. Closed soilless growing system for producing strawberry bare root transplants and runner tips Sistema fechado de cultivo sem solo para produção de mudas de raízes nuas e de pontas de estolões de morangueiro

    Directory of Open Access Journals (Sweden)

    Gustavo Giménez

    2008-12-01

    Full Text Available The objective of this work was to test a closed soilless growing system for producing bare root transplants and runner tips of two strawberry clones, using two categories of substrates. The system used corrugated roofing panels of fiber-cement, over which a substrate layer was used as a growing bed. The nutrient solution was pumped from a reservoir toward the upper end of the roofing panels and drained back to a reservoir. Plant growth and development were determined for two advanced strawberry clones, grown in sand or in Plantmax organic substrate. Growth of the stock plants and the number and dry mass of bare root transplants were similar in the substrates, but bare roots differed in their crown diameters by substrate. For number of runner tips, no significant differences were found in total, small, and medium categories in the substrates. A mean production of about 590 runner tips per square meter and 145 bare root transplants per square meter was obtained. For both clones, a large number of bare root transplants and runner tips of adequate size were produced in the closed soilless growing system using sand or organic substrate.O objetivo deste trabalho foi testar um sistema fechado de cultivo sem solo, para a produção de mudas e pontas de estolões de dois clones de morangueiro, com uso de duas categorias de substrato. O sistema foi constituído por um leito de cultivo formado por telhas de fibrocimento, com uma camada de substrato como leito de cultivo. A solução nutritiva foi bombeada de um reservatório até a extremidade mais alta da telha e drenada de volta ao reservatório. Foram determinados o crescimento e o desenvolvimento de dois clones avançados de morangueiro, plantados na areia e no substrato orgânico Plantmax. O crescimento das plantas matrizes foi similar nos dois substratos. O número e a massa de matéria seca das mudas de raízes nuas foram semelhantes nos dois substratos, mas diferiram nos diâmetros de coroa. Quanto

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

    Science.gov (United States)

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

    2009-01-01

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

  10. External root resorption after orthodontic treatment: a study of contributing factors

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yun Hoa; Cho, Bong Hae [School of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    2011-03-15

    The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

  11. External root resorption after orthodontic treatment: a study of contributing factors

    International Nuclear Information System (INIS)

    Jung, Yun Hoa; Cho, Bong Hae

    2011-01-01

    The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

  12. First Aid Tips

    Science.gov (United States)

    ... Program Diversity In Vision Research & Ophthalmology (DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home » NEI for Kids » First Aid Tips Listen All About Vision About the Eye ...

  13. Tips for Daily Life

    Science.gov (United States)

    ... chapter Join our online community Tips for Daily Life Coping skills will help you handle day-to- ... challenges, maximize your independence and live a meaningful life with your diagnosis. Accepting changes Creating a coping ...

  14. Toilet training tips

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000944.htm Toilet training tips To use the sharing features on ... and 'pee'. Teaching Your Child to Use the Toilet Once your child is comfortable sitting on the ...

  15. Root rots

    Science.gov (United States)

    Kathryn Robbins; Philip M. Wargo

    1989-01-01

    Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and...

  16. The actin Cytoskeleton in Root Hairs: a cell elongation device

    NARCIS (Netherlands)

    Ketelaar, T.; Emons, A.M.C.

    2009-01-01

    The actin cytoskeleton plays an important role in root hair development. It is involved in both the delivery of growth materials to the expanding tip of root hairs and the regulation of the area of tip growth. This review starts with a discussion of the techniques that are available to visualize the

  17. Tips from the Classroom.

    Science.gov (United States)

    Wilhelm, Kim Hughes; Leverett, Thomas; Barrett, Rob J.; Chur-Hansen, Anna; Dantas-Whitney, Maria; Zapata, Gabriela; Garcia, Juan Felix

    1998-01-01

    Five articles present tips for rallying English-as-a-Second-Language students to the enterprise of creating context, tools, and language itself. The articles focus on using original dramas created by students, teaching nonnative English-speaking medical students to comprehend their patients' colloquial language, conducting research with native…

  18. Air Travel Health Tips

    Science.gov (United States)

    ... Conditions Prevention and Wellness Staying Healthy Healthy Living Travel Occupational Health First Aid and Injury Prevention Crisis ... MoreDepression in Children and TeensRead MoreBMI Calculator International Travel: Tips for Staying HealthyTexting and DrivingTravel Needs for ...

  19. 10 Data Visualization Tips

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

    Office 2004 Test Drive User

    communicated through the use of design choices. (as indicated in tip 8). 8. Use colour, size, and position to help the reader see what is important. Colour adds emphasis, highlights particular data points, and draws connections between graphs. The hue, value, and intensity of the colour are significant and may have cultural ...

  20. Sports Dehydration Safety Tips

    Science.gov (United States)

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

  1. Automated Tracking of Root for Confocal Time-lapse Imaging of Cellular Processes

    OpenAIRE

    Doumane, Mehdi; Lionnet, Claire; Bayle, Vincent; Jaillais, Yvon; Caillaud, Marie-C?cile

    2017-01-01

    Here we describe a protocol that enables to automatically perform time-lapse imaging of growing root tips for several hours. Plants roots expressing fluorescent proteins or stained with dyes are imaged while they grow using automatic movement of the microscope stage that compensates for root growth and allows to follow a given region of the root over time. The protocol makes possible the image acquisition of multiple growing root tips, therefore increasing the number of recorded mitotic event...

  2. Collection of gravitropic effectors from mucilage of electrotropically-stimulated roots of Zea mays L

    Science.gov (United States)

    Fondren, W. M.; Moore, R.

    1987-01-01

    We placed agar blocks adjacent to tips of electrotropically stimulated primary roots of Zea mays. Blocks placed adjacent to the anode-side of the roots for 3 h induced significant curvature when subsequently placed asymmetrically on tips of vertically-oriented roots. Curvature was always toward the side of the root unto which the agar block was placed. Agar blocks not contacting roots and blocks placed adjacent to the cathode-side of electrotropically stimulated roots did not induce significant curvature when placed asymmetrically on tips of vertically-oriented roots. Atomic absorption spectrophotometry indicated that blocks adjacent to the anode-side of electrotropically-stimulated roots contained significantly more calcium than (1) blocks not contacting roots, and (2) blocks contacting the cathode-side of roots. These results demonstrate the presence of a gradient of endogenous Ca in mucilage of electrotropically-stimulated roots (i.e. roots undergoing gravitropic-like curvature).

  3. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... TIPS. top of page What are some common uses of the procedure? A TIPS is used to ... the scanner by a cord. Some exams may use different transducers (with different capabilities) during a single ...

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

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

  5. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

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

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

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

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... heart while avoiding the liver. TIPS may successfully reduce internal bleeding in the stomach and esophagus in ... TIPS reroutes blood flow in the liver and reduces abnormally high blood pressure in the veins of ...

  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... What are the limitations of TIPS? What is a Transjugular Intrahepatic Portosystemic Shunt (TIPS)? A transjugular intrahepatic ... taking our brief survey: Survey Do you have a personal story about radiology? Share your patient story ...

  9. Methods for pretreating biomass

    Science.gov (United States)

    Balan, Venkatesh; Dale, Bruce E; Chundawat, Shishir; Sousa, Leonardo

    2017-05-09

    A method for pretreating biomass is provided, which includes, in a reactor, allowing gaseous ammonia to condense on the biomass and react with water present in the biomass to produce pretreated biomass, wherein reactivity of polysaccharides in the biomass is increased during subsequent biological conversion as compared to the reactivity of polysaccharides in biomass which has not been pretreated. A method for pretreating biomass with a liquid ammonia and recovering the liquid ammonia is also provided. Related systems which include a biochemical or biofuel production facility are also disclosed.

  10. Tip vorticity reduction and optimization of lifting surfaces

    NARCIS (Netherlands)

    Sparenberg, JA

    In linearized optimization theory, lifting surfaces, moving in an inviscid and incompressible fluid, shed tip vorticity of which the strength has infinite square-root singularities. Here we discuss that an optimization procedure can be coupled to constraints so that the strength of the shed

  11. Migraine strikes as neuronal excitability reaches a tipping point

    NARCIS (Netherlands)

    Scheffer, Marten; van den Berg, Albert; Ferrari, Michel D.

    2013-01-01

    Self-propagating waves of cerebral neuronal firing, known as spreading depolarisations, are believed to be at the roots of migraine attacks. We propose that the start of spreading depolarisations corresponds to a critical transition that occurs when dynamic brain networks approach a tipping point.

  12. Migraine Strikes as Neuronal Excitability Reaches a Tipping Point

    NARCIS (Netherlands)

    Scheffer, M.; Berg, van den A.; Ferrari, B.

    2013-01-01

    Self-propagating waves of cerebral neuronal firing, known as spreading depolarisations, are believed to be at the roots of migraine attacks. We propose that the start of spreading depolarisations corresponds to a critical transition that occurs when dynamic brain networks approach a tipping point.

  13. Light and decapitation effects on in vitro rooting in maize root segments.

    Science.gov (United States)

    Golaz, F W; Pilet, P E

    1985-10-01

    The effects of white light and decapitation on the initiation and subsequent emergence and elongation of lateral roots of apical maize (Zea mays L. cv LG 11) root segments have been examined. The formation of lateral root primordium was inhibited by the white light. This inhibition did not depend upon the presence of the primary root tip. However, root decapitation induced a shift of the site of appearance of the most apical primordium towards the root apex, and a strong disturbance of the distribution pattern of primordium volumes along the root axis. White light had a significant effect neither on the distribution pattern of primordium volumes, nor on the period of primordium development (time interval required for the smallest detectable primordia to grow out as secondary roots). Thus, considering the rooting initiation and emergence, the light effect was restricted to the initiation phase only. Moreover, white light reduced lateral root elongation as well as primary root growth.

  14. Cyclic programmed cell death stimulates hormone signaling and root development in Arabidopsis

    NARCIS (Netherlands)

    Xuan, Wei; Band, Leah R.; Kumpf, Robert P.; Rybel, De Bert

    2016-01-01

    The plant root cap, surrounding the very tip of the growing root, perceives and transmits environmental signals to the inner root tissues. In Arabidopsis thaliana, auxin released by the root cap contributes to the regular spacing of lateral organs along the primary root axis. Here, we show that

  15. Laser-induced agitation and cavitation from proprietary honeycomb tips for endodontic applications.

    Science.gov (United States)

    George, Roy; Chan, Keith; Walsh, Laurence James

    2015-05-01

    Cavitation and agitation generated by lasers in fluid-filled root canals create fluid movement and shear stresses along the root canals walls, enhancing removal of the smear layer and biofilm. When used with sodium hypochlorite and EDTA, laser activation of aqueous fluids can increase the efficiency of debridement and disinfection of root canals. However, the use of forward-firing laser fibers with such solutions poses a risk of driving fluid past the root apex, which could cause postoperative complications. The purpose of this study was to evaluate the mechanism of fluid agitation caused by a novel honeycomb tip. Glass capillary tubes filled with distilled water were used to replicate single-tooth root canals. A 980 nm pulsed diode laser was used with 200 μm diameter plain tips, tube-etched conical tips, and honeycomb tips. To record fluid movements, the tubes were backlit and imaged using a digital camera attached to a microscope. The honeycomb tips generated agitation with fluid movement directed onto the walls, while both the conventional plain fibers and the conical tips created fluid movement largely in a forward direction. The use of honeycomb tips alters the pattern of fluid agitation, and this laterally directed effect might lower the risk of fluid extrusion beyond the apex.

  16. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... liver disease are at greater risk for worsening liver failure after TIPS. If your liver failure is severe, a TIPS may not be the best use and a different procedure may be needed to control your symptoms. ... ordinarily filtered out by the liver. The TIPS may cause too much of these ...

  17. Observations on the feeding and symptomatology of xiphinema and longidorus on selected host roots.

    Science.gov (United States)

    Cohn, E

    1970-04-01

    In vitro feeding of Xiphinema brevicolle, X. index and Longidorus africanus on roots of host seedlings is described. Both Xiphinema spp. fed mainly along roots rather than at tips and up to several days at a single site. Feeding of L. africanus was confined to root tips and lasted up to 15 min. No visible short term reaction of roots parasitized by the Xiphinema spp. could be discerned, but both swelling and cessation of growth of root tips were observed within 20 hr after feeding by L. africanus. Long-term (12-month) symptoms on roots of several host plants caused by cultured populations of X. brevicolle, X. index, X. italiae, L. africanus and L. brevicaudatus are described. All the Xiphinema spp. caused a thinning and distinct darkening of root systems and, at some sites, a breakdown of the cortex. Both species of Longidorus caused stubby and swollen root tips. Root symptom severity was in proportion to nematode population levels.

  18. Effects of long-term temperature and nutrient manipulation on Norway spruce fine roots and mycelia production

    DEFF Research Database (Denmark)

    Leppälammi-Kujansuu, J.; Ostonen, I.; Strömgren, M.

    2013-01-01

    Aims and methods The effects of changing climate on ectomycorrhizal (EcM) fine roots were studied in northern Sweden by manipulating soil temperature for 14 years and/or by fertilizing for 22 years. Fine root biomass, necromass, EcM root tip biomass, morphology and number as well as mycelia...... production were determined from soil cores and mesh bags. Results and conclusions The fine root biomass and necromass were highest in the fertilized plots, following similar trends in the above-ground biomass, whereas the EcM root tip biomass per basal area decreased by 22 % in the fertilized plots compared...... to the control. Warming increased the fine root biomass, live/dead-ratio and the number of EcM root tips in the mineral soil and tended to increase the production of EcM mycelia. Greater fine root biomass meant more EcM root tips, although the tip frequency was not affected by fertilization or warming...

  19. Tip-modified Propellers

    DEFF Research Database (Denmark)

    Andersen, Poul

    1999-01-01

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

  20. Pretreatment of microbial sludges

    Science.gov (United States)

    Rivard, Christopher J.; Nagle, Nicholas J.

    1995-01-01

    Methods are described for pretreating microbial sludges to break cells and disrupt organic matter. One method involves the use of sonication, and another method involves the use of shear forces. The pretreatment of sludge enhances bioconversion of the organic fraction. This allows for efficient dewatering of the sludge and reduces the cost for final disposal of the waste.

  1. Comparison of different types of phacoemulsification tips. I. Quantitative analysis of elemental composition and tip surface microroughness.

    Science.gov (United States)

    Tsaousis, Konstantinos T; Werner, Liliana; Perez, Jesus Paulo; Li, He J; Reiter, Nicholas; Guan, Jia J; Mamalis, Nick

    2016-09-01

    To evaluate the elemental composition of phacoemulsification tips and their surface roughness in the microscale. John A. Moran Eye Center and Utah Nanofab, College of Engineering, University of Utah, Salt Lake City, Utah, USA. Experimental study. Seven types of phacoemulsification tips were studied. The phaco tips were examined through energy-dispersive x-ray spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) for elemental composition. In addition, the roughness of the opening in all tips was assessed through 3-dimensional white-light interferometry. Elemental analysis showed considerable differences in the surface layers between manufacturers. Alcon tips had a thinner oxidized titanium (Ti) layer in their surface. Through XPS, vanadium was not detected in the superficial layers of any tip, but only in deeper levels. The microroughness surface analysis showed comparable results regarding their root-mean-square (RMS) metric. Maximum peak valley distance values varied and appeared to be dependent on the quality of material process rather than the material itself. Phacoemulsification tips are made of Ti alloys and showed differences between models, especially regarding their composition in the superficial layers. Their opening end roughness showed an overall appropriate RMS value of less than 1.0 μm in all cases. The existence of small defected areas highlights the importance of adequate quality control of these critical surgical instruments. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    1989-01-01

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

  3. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  4. Tipping point leadership.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2003-04-01

    When William Bratton was appointed police commissioner of New York City in 1994, turf wars over jurisdiction and funding were rife and crime was out of control. Yet in less than two years, and without an increase in his budget, Bratton turned New York into the safest large city in the nation. And the NYPD was only the latest of five law-enforcement agencies Bratton had turned around. In each case, he succeeded in record time despite limited resources, a demotivated staff, opposition from powerful vested interests, and an organization wedded to the status quo. Bratton's turnarounds demonstrate what the authors call tipping point leadership. The theory of tipping points hinges on the insight that in any organization, fundamental changes can occur quickly when the beliefs and energies of a critical mass of people create an epidemic movement toward an idea. Bratton begins by overcoming the cognitive hurdles that block organizations from recognizing the need for change. He does this by putting managers face-to-face with operational problems. Next, he manages around limitations on funds, staff, or equipment by concentrating resources on the areas that are most in need of change and that have the biggest payoffs. He meanwhile solves the motivation problem by singling out key influencers--people with disproportionate power due to their connections or persuasive abilities. Finally, he closes off resistance from powerful opponents. Not every CEO has the personality to be a Bill Bratton, but his successes are due to much more than his personality. He relies on a remarkably consistent method that any manager looking to turn around an organization can use to overcome the forces of inertia and reach the tipping point.

  5. Effect of ultrasonic tip designs on intraradicular post removal

    Directory of Open Access Journals (Sweden)

    Anny Carine Barros Aguiar

    2014-11-01

    Full Text Available Objectives To evaluate the effect of different ultrasonic tip designs on intraradicular post removal. Materials and Methods The crowns of forty human canine teeth were removed, and after biomechanical preparation and filling, the roots were embedded in acrylic resin blocks. The post spaces were made, and root canal molding was performed with self-cured acrylic resin. After casting (Cu-Al, the posts were cemented with zinc phosphate cement. The specimens were randomly separated into 4 groups (n = 10, as follows: G1 - no ultrasonic vibration (control; G2 - ultrasonic vibration using an elongated cylindrical-shaped and active rounded tip; G3 - ultrasonic vibration with a flattened convex and linear active tip; G4 - ultrasonic vibration with active semicircular tapered tip. Ultrasonic vibration was applied for 15 seconds on each post surface and tensile test was performed in a Universal Testing Machine (Instron 4444 - 1 mm/min. Results G4 presented the highest mean values, however, with no statistically significant difference in comparison to G3 (P > 0.05. G2 presented the lowest mean values with statistically significant difference to G3 and G4 (P < 0.05. Conclusions Ultrasonic vibration with elongated cylindrical-shaped and active rounded tip was most effective in reducing force required for intraradicular post removal.

  6. ALA Pretreatment Improves Waterlogging Tolerance of Fig Plants.

    Directory of Open Access Journals (Sweden)

    Yuyan An

    Full Text Available 5-aminolevulinic acid (ALA, a natural and environmentally friendly plant growth regulator, can improve plant tolerance to various environmental stresses. However, whether ALA can improve plant waterlogging tolerance is unknown. Here, we investigated the effects of ALA pretreatment on the waterlogging-induced damage of fig (Ficus carica Linn. plants, which often suffer from waterlogging stress. ALA pretreatment significantly alleviated stress-induced morphological damage, increased leaf relative water content (RWC, and reduced leaf superoxide anion ([Formula: see text] production rate and malonaldehyde (MDA content in fig leaves, indicating ALA mitigates waterlogging stress of fig plants. We further demonstrated that ALA pretreatment largely promoted leaf chlorophyll content, photosynthetic electron transfer ability, and photosynthetic performance index, indicating ALA significantly improves plant photosynthetic efficiency under waterlogging stress. Moreover, ALA pretreatment significantly increased activities of leaf superoxide dismutase (SOD and peroxidase (POD, root vigor, and activities of root alcohol dehydrogenase (ADH, and lactate dehydrogenase (LDH, indicating ALA also significantly improves antioxidant ability and root function of fig plants under waterlogging stress. Taken together, ALA pretreatment improves waterlogging tolerance of fig plants significantly, and the promoted root respiration, leaf photosynthesis, and antioxidant ability may contribute greatly to this improvement. Our data firstly shows that ALA can improve plant waterlogging tolerance.

  7. Defoliation of strawberry mother plants for the production of runner tips

    Directory of Open Access Journals (Sweden)

    Miriane Dal Picio

    2014-07-01

    Full Text Available The objective of this work was to determine the sink-source relationships and their effects on the number and growth of runner tips of 'Camino Real' strawberry stock plants. Three types of sources were evaluated: one defoliation at 96 days after planting (DAP, two defoliations at 50 and 96 DAP, and mother plants without defoliation. Four types of sink were accessed: runner tips collected weekly and monthly, four stolons with rooted runner tips in pots, and four freely-grown stolons. A completely randomized experimental design was used in a split-plot arrangement, with four replicates. The source types were placed in the plots, and sink types in the subplots. The number of runner tips, the crown diameter, and the dry matter mass were determined. Number and growth of tips were higher on plants without defoliation, and decreased 44.7% on twice-defoliated mother plants. The two-defoliation management did not reduce runner tip dry matter mass only on plants with rooted stolons, which produced runner tips 50% heavier. Defoliation of mother plants bearing rooting stolons can be used to reduce their growth, without reducing the emission and growth of runner tips.

  8. Sites and regulation of auxin biosynthesis in Arabidopsis roots.

    Science.gov (United States)

    Ljung, Karin; Hull, Anna K; Celenza, John; Yamada, Masashi; Estelle, Mark; Normanly, Jennifer; Sandberg, Göran

    2005-04-01

    Auxin has been shown to be important for many aspects of root development, including initiation and emergence of lateral roots, patterning of the root apical meristem, gravitropism, and root elongation. Auxin biosynthesis occurs in both aerial portions of the plant and in roots; thus, the auxin required for root development could come from either source, or both. To monitor putative internal sites of auxin synthesis in the root, a method for measuring indole-3-acetic acid (IAA) biosynthesis with tissue resolution was developed. We monitored IAA synthesis in 0.5- to 2-mm sections of Arabidopsis thaliana roots and were able to identify an important auxin source in the meristematic region of the primary root tip as well as in the tips of emerged lateral roots. Lower but significant synthesis capacity was observed in tissues upward from the tip, showing that the root contains multiple auxin sources. Root-localized IAA synthesis was diminished in a cyp79B2 cyp79B3 double knockout, suggesting an important role for Trp-dependent IAA synthesis pathways in the root. We present a model for how the primary root is supplied with auxin during early seedling development.

  9. MES buffer affects Arabidopsis root apex zonation and root growth by suppressing superoxide generation in root apex

    Directory of Open Access Journals (Sweden)

    Tomoko eKagenishi

    2016-02-01

    Full Text Available In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species. MES, 2-(N-morpholinoethanesulfonic acid as one of the Good’s buffers has broadly been used for buffering medium, and it is thought to suit for plant growth with the concentration at 0.1% (w/v because the buffer capacity of MES ranging pH 5.5-7.0 (for Arabidopsis, pH 5.8. However, many reports have shown that, in nature, roots require different pH values on the surface of specific root apex zones, namely meristem, transition zone and elongation zone. Despite the fact that roots always grow on a media containing buffer molecule, little is known about impact of MES on root growth. Here, we have checked the effects of different concentrations of MES buffer using growing roots of Arabidopsis thaliana. Our results show that 1% of MES significantly inhibited root growth, the number of root hairs and length of meristem, whereas 0.1% promoted root growth and root apex area (region spanning from the root tip up to the transition zone. Furthermore, superoxide generation in root apex disappeared at 1% of MES. These results suggest that MES disturbs normal root morphogenesis by changing the reactive oxygen species (ROS homeostasis in root apex.

  10. MES Buffer Affects Arabidopsis Root Apex Zonation and Root Growth by Suppressing Superoxide Generation in Root Apex.

    Science.gov (United States)

    Kagenishi, Tomoko; Yokawa, Ken; Baluška, František

    2016-01-01

    In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species (ROS). MES, 2-(N-morpholino)ethanesulfonic acid as one of the Good's buffers has broadly been used for buffering medium, and it is thought to suit for plant growth with the concentration at 0.1% (w/v) because the buffer capacity of MES ranging pH 5.5-7.0 (for Arabidopsis, pH 5.8). However, many reports have shown that, in nature, roots require different pH values on the surface of specific root apex zones, namely meristem, transition zone, and elongation zone. Despite the fact that roots always grow on a media containing buffer molecule, little is known about impact of MES on root growth. Here, we have checked the effects of different concentrations of MES buffer using growing roots of Arabidopsis thaliana. Our results show that 1% of MES significantly inhibited root growth, the number of root hairs and length of meristem, whereas 0.1% promoted root growth and root apex area (region spanning from the root tip up to the transition zone). Furthermore, superoxide generation in root apex disappeared at 1% of MES. These results suggest that MES disturbs normal root morphogenesis by changing the ROS homeostasis in root apex.

  11. AERODYNAMICS OF WING TIP SAILS

    Directory of Open Access Journals (Sweden)

    MUSHTAK AL-ATABI

    2006-06-01

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

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... liver disease are at greater risk for worsening liver failure after TIPS. If your liver failure is severe, a TIPS may not be the ... children are more likely to be performed before liver transplant in those with ascites or variceal ... 08, 2017 Send us your feedback Did you find the ...

  13. A gradient of endogenous calcium forms in mucilage of graviresponding roots of Zea mays

    Science.gov (United States)

    Moore, R.; Fondren, W. M.

    1988-01-01

    Agar blocks that contacted the upper sides of tips of horizontally-oriented roots of Zea mays contain significantly less calcium (Ca) than blocks that contacted the lower sides of such roots. This gravity-induced gradient of Ca forms prior to the onset of gravicurvature, and does not form across tips of vertically-oriented roots or roots of agravitropic mutants. These results indicate that (1) Ca can be collected from mucilage of graviresponding roots, (2) gravity induces a downward movement of endogenous Ca in mucilage overlying the root tip, (3) this gravity-induced gradient of Ca does not form across tips of agravitropic roots, and (4) formation of a Ca gradient is not a consequence of gravicurvature. These results are consistent with gravity-induced movement of Ca being a trigger for subsequent redistribution of growth effectors (e.g. auxin) that induce differential growth and gravicurvature.

  14. Al-induced root cell wall chemical components differences of wheat ...

    African Journals Online (AJOL)

    Root growth is different in plants with different levels of Al-tolerance under Al stress. Cell wall chemical components of root tip cell are related to root growth. The aim of this study was to explore the relationship between root growth difference and cell wall chemical components. For this purpose, the cell wall chemical ...

  15. The Effect of Low Oxygen Stress on Phytophthora cinnamomi Infection and Disease of Cork Oak Roots

    Science.gov (United States)

    Karel A. Jacobs; James D. MacDonald; Alison M. Berry; Laurence R. Costello

    1997-01-01

    The incidence and severity of Phytophthora cinnamomi Rands root disease was quantified in cork oak (Quercus suber L.) roots subjected to low oxygen (hypoxia) stress. Seedling root tips were inoculated with mycelial plugs of the fungus and incubated in ≤1, 3-4, or 21 percent oxygen for 5 days. Ninety-four percent of roots...

  16. A new strategy in root canal therapy: there is a lot going on in endodontic disinfection

    NARCIS (Netherlands)

    van der Waal, S.V.

    2015-01-01

    Apical periodontitis (AP) is the inflammatory response in the surrounding tissues at the root tip of a tooth to a microbial infection of the root canal system inside the tooth. AP can only resolve after thorough root canal disinfection. However at present, state-of-the-art root canal treatment does

  17. Complex Regulation of Prolyl-4-Hydroxylases Impacts Root Hair Expansion

    DEFF Research Database (Denmark)

    Velasquez, Silvia M; Ricardi, Martiniano M; Poulsen, Christian Peter

    2015-01-01

    Root hairs are single cells that develop by tip growth, a process shared with pollen tubes, axons, and fungal hyphae. However, structural plant cell walls impose constraints to accomplish tip growth. In addition to polysaccharides, plant cell walls are composed of hydroxyproline-rich glycoprotein...... peptidyl-proline hydroxylation on EXTs, and possibly in other HRGPs, is required for proper cell wall self-assembly and hence root hair elongation in Arabidopsis thaliana....

  18. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  19. Stability of helical tip vortices in a rotor far wake

    DEFF Research Database (Denmark)

    Okulov, Valery; Sørensen, Jens Nørkær

    2007-01-01

    , corresponding to Rankine, Gaussian and Scully vortices, at radial extents ranging from the core radius of a tip vortex to several rotor radii. The analysis shows that the stability of tip vortices largely depends on the radial extent of the hub vorticity as well as on the type of vorticity distribution. As part......As a means of analysing the stability of the wake behind a multi-bladed rotor the stability of a multiplicity of helical vortices embedded in an assigned flow field is addressed. In the model the tip vortices in the far wake are approximated by infinitely long helical vortices with constant pitch...... and radius. The work is a further development of a model developed in Okulov (J. Fluid Mech., vol. 521, p. 319) in which the linear stability of N equally azimuthally spaced helical vortices was considered. In the present work the analysis is extended to include an assigned vorticity field due to root...

  20. Microwave pretreatment of switchgrass for bioethanol production

    Science.gov (United States)

    Keshwani, Deepak Radhakrishin

    conditions, 82% glucose and 63% xylose yields were achieved for switchgrass, and 87% glucose and 59% xylose yields were achieved for coastal bermudagrass following enzymatic hydrolysis of the pretreated biomass. The optimum enzyme loadings were 15 FPU/g and 20 CBU/g for switchgrass and 10 FPU/g and 20 CBU/g for coastal bermudagrass. Dielectric properties for dilute sodium hydroxide solutions were measured and compared to solid loss, lignin reduction and reducing sugar levels in hydrolyzates. Results indicate that the dielectric loss tangent of alkali solutions is a potential indicator of the severity of microwave-based pretreatments. Modeling of pretreatment processes can be a valuable tool in process simulations of bioethanol production from lignocellulosic biomass. Chapter 4 discusses three different approaches that were used to model delignification and carbohydrate loss during microwave-based pretreatment of switchgrass: statistical linear regression modeling, kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. The dielectric loss tangent of the alkali reagent and pretreatment time were used as predictors in all models. The statistical linear regression model for delignification gave comparable root mean square error (RMSE) values for training and testing data and predictions were approximately within 1% of experimental values. The kinetic model for delignification and xylan loss gave comparable RMSE values for training and testing data sets and predictions were approximately within 2% of experimental values. The kinetic model for cellulose loss was not as effective and predictions were only within 5-7% of experimental values. The time-dependent rate coefficients of the kinetic models calculated from experimental data were consistent with the heterogeneity (or lack thereof) of individual biomass components. The Mamdani-type fuzzy inference system was shown to be an effective means to model pretreatment processes and gave

  1. Defining tipping points for social-ecological systems scholarship—an interdisciplinary literature review

    Science.gov (United States)

    Milkoreit, Manjana; Hodbod, Jennifer; Baggio, Jacopo; Benessaiah, Karina; Calderón-Contreras, Rafael; Donges, Jonathan F.; Mathias, Jean-Denis; Rocha, Juan Carlos; Schoon, Michael; Werners, Saskia E.

    2018-03-01

    The term tipping point has experienced explosive popularity across multiple disciplines over the last decade. Research on social-ecological systems (SES) has contributed to the growth and diversity of the term’s use. The diverse uses of the term obscure potential differences between tipping behavior in natural and social systems, and issues of causality across natural and social system components in SES. This paper aims to create the foundation for a discussion within the SES research community about the appropriate use of the term tipping point, especially the relatively novel term ‘social tipping point.’ We review existing literature on tipping points and similar concepts (e.g. regime shifts, critical transitions) across all spheres of science published between 1960 and 2016 with a special focus on a recent and still small body of work on social tipping points. We combine quantitative and qualitative analyses in a bibliometric approach, rooted in an expert elicitation process. We find that the term tipping point became popular after the year 2000—long after the terms regime shift and critical transition—across all spheres of science. We identify 23 distinct features of tipping point definitions and their prevalence across disciplines, but find no clear taxonomy of discipline-specific definitions. Building on the most frequently used features, we propose definitions for tipping points in general and social tipping points in SES in particular.

  2. GREET Pretreatment Module

    Energy Technology Data Exchange (ETDEWEB)

    Adom, Felix K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

    2014-09-01

    A wide range of biofuels and biochemicals can be produced from cellulosic biomass via different pretreatment technologies that yield sugars. Process simulations of dilute acid and ammonia fiber expansion pretreatment processes and subsequent hydrolysis were developed in Aspen Plus for four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar). This processing yields sugars that can be subsequently converted to biofuels or biochemical. Material and energy consumption data from Aspen Plus were then compiled in a new Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREETTM) pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

  3. Xyloglucan, galactomannan, glucuronoxylan, and rhamnogalacturonan I do not have identical structures in soybean root and root hair cell walls.

    Science.gov (United States)

    Muszyński, Artur; O'Neill, Malcolm A; Ramasamy, Easwaran; Pattathil, Sivakumar; Avci, Utku; Peña, Maria J; Libault, Marc; Hossain, Md Shakhawat; Brechenmacher, Laurent; York, William S; Barbosa, Rommel M; Hahn, Michael G; Stacey, Gary; Carlson, Russell W

    2015-11-01

    Chemical analyses and glycome profiling demonstrate differences in the structures of the xyloglucan, galactomannan, glucuronoxylan, and rhamnogalacturonan I isolated from soybean ( Glycine max ) roots and root hair cell walls. The root hair is a plant cell that extends only at its tip. All other root cells have the ability to grow in different directions (diffuse growth). Although both growth modes require controlled expansion of the cell wall, the types and structures of polysaccharides in the walls of diffuse and tip-growing cells from the same plant have not been determined. Soybean (Glycine max) is one of the few plants whose root hairs can be isolated in amounts sufficient for cell wall chemical characterization. Here, we describe the structural features of rhamnogalacturonan I, rhamnogalacturonan II, xyloglucan, glucomannan, and 4-O-methyl glucuronoxylan present in the cell walls of soybean root hairs and roots stripped of root hairs. Irrespective of cell type, rhamnogalacturonan II exists as a dimer that is cross-linked by a borate ester. Root hair rhamnogalacturonan I contains more neutral oligosaccharide side chains than its root counterpart. At least 90% of the glucuronic acid is 4-O-methylated in root glucuronoxylan. Only 50% of this glycose is 4-O-methylated in the root hair counterpart. Mono O-acetylated fucose-containing subunits account for at least 60% of the neutral xyloglucan from root and root hair walls. By contrast, a galacturonic acid-containing xyloglucan was detected only in root hair cell walls. Soybean homologs of the Arabidopsis xyloglucan-specific galacturonosyltransferase are highly expressed only in root hairs. A mannose-rich polysaccharide was also detected only in root hair cell walls. Our data demonstrate that the walls of tip-growing root hairs cells have structural features that distinguish them from the walls of other roots cells.

  4. Tipping the scales.

    Science.gov (United States)

    1998-12-01

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

  5. Torsional Phacoemulsification and Tip Selection

    Directory of Open Access Journals (Sweden)

    Fırat Helvacıoğlu

    2014-10-01

    Full Text Available One of the recent advances in cataract surgery is torsional phacoemulsification. It was developed to increase the efficacy of ultrasonic emulsification. In torsional phacoemulsification, the torsional movement of the tip is translated to side-to-side cutting action with the aid of bent phaco tips. Lens material is cut in both directions, rather than only during a forward stroke. The efficiency of this technique is further enhanced by an improvement in followability provided by the inherent non-repulsive nature of the side-to-side motion. Tip selection is very important for the efficiency of torsional phacoemulsification. Theoretically, there are 2 ways to enhance the cutting efficiency of the tip. First is the stroke length; the 22-degree bent 30-degree Kelman mini-flared tip cuts longer than the 12-degree bent 30-degree mini-flared Kelman tip. Second is the angulation or bevel; the higher the degree (45 degrees, the better cutting efficiency. Retrospective analyses of the previously published clinical studies clearly demonstrated that the efficacy of the torsional phacoemulsification has positive correlation with both the aperture angles and neck angles of the tips. (Turk J Ophthalmol 2014; 44: 392-5

  6. Auxin transport and growth in intact roots of Vicia faba

    International Nuclear Information System (INIS)

    Ohwaki, Yoriko; Tsurumi, Seiji

    1976-01-01

    Transport of IAA applied to the intact root of Vicia seedlings was investigated in relation to root growth. The root was treated at 3-4,4-5 or 7-8mm from the tip with a narrow ring of lanolin paste containing IAA or IAA-2- 14 C in growth or transport experiments, repectively. The growth process along the root axis was examined in every 1-mm part from the tip at 30 min, 1 or 4 hr intervals. The elongation zone of the control root was 1-9mm from the tip. IAA treatment brought about no significant change in the growth of the region apical to the treated site, whereas distinct inhibition of growth occurred in the region basal to the treated site within 1 hr. The transport of radioactivity was observed in both acropetal and basipetal directions within 1 hr, but the later predominated for 8 hr or more; the nearer to the tip the treatment site, the longer the predominance lasted. The velocities of acropetal and basipetal transport were estimated at about 4 and 8 mm/hr, respectively. Autoradiographs of transverse section of roots showed that basipetal transport occurred mainly through the outer part of the root, whereas acropetal transport occurred mainly through the inner part, the central cylinder. It may be concluded that the basipetally transported IAA which passed cylinder. It may be concluded that the basipetally transported IAA which passed through the outer part of the root inhibited the elongation of the intact root. (auth.)

  7. Advances in aluminum pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sudour, Michel; Maintier, Philippe [PPG Industries France, 3 Z.A.E. Les Dix Muids, B.P. 89, F-59583 Marly (France); Simpson, Mark [PPG Industries Inc., 1200 Piedmont Troy, Michigan 48083 (United States); Quaglia, Paolo [PPG Industries Italia, Via Garavelli 21, I-15028 Quattordio (Italy)

    2004-07-01

    As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply were not designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective. Thus, the complexities of pre-treating aluminum body panels have actually had a negative effect on efforts to introduce more aluminum into new vehicle design programs. Recent research into ways of reducing the negative effects has led to a new understanding of the nature of zinc phosphate bath -aluminum interactions. Many of the issues associated with the pretreatment of aluminum have been identified and can be mitigated with only minor changes to the zinc phosphate bath chemistry. The use of low levels of soluble Fe ions, together with free fluoride, has been shown to dramatically improve the efficiency of a zinc phosphate system processing aluminum. Appearance of zinc phosphate coatings, coating weights and sludge are all benefited by this chemistry change. (authors)

  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  9. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Transjugular Intrahepatic Portosystemic Shunt (TIPS) Transjugular ... in the portal vein system. This pressure buildup can cause blood to flow backward from the liver ...

  10. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

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

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  13. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... and lengthy procedures requiring extended fluoroscopy use) death (rare) top of page What are the limitations of TIPS? Patients with more advanced liver disease are at greater risk for worsening liver failure ...

  14. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... less likely to require a TIPS. top of page What are some common uses of the procedure? A ... gown to wear during the procedure. top of page What does the equipment look like? In this procedure, ...

  15. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... the hepatic vein in the liver. A small metal device called a stent is placed to keep ... open by the placement of a small, tubular metal device commonly called a stent . During a TIPS ...

  16. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... of bleeding that can occur can sometimes be life threatening and those patients are monitored in intensive ... invasive procedure that typically has a shorter recovery time than surgery. Your TIPS should have less of ...

  17. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  18. Choking and Strangulation Prevention Tips

    Science.gov (United States)

    ... Safety Sponsors Recalls Media Center Blog Videos Newsletter facebook twitter instagram pinterest gplus youtube Search Menu Why It Matters ... Safety Sponsors Recalls Media Center Blog Videos Newsletter facebook twitter instagram pinterest gplus youtube Sign up for quick tips ...

  19. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  20. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This page ... American College of Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise ...

  1. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  2. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... TIPS may successfully reduce internal bleeding in the stomach and esophagus in patients with cirrhosis. Tell your ... the liver into the veins of the spleen, stomach, lower esophagus, and intestines, causing enlarged vessels, bleeding ...

  3. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... in an hour or two but may take up to several hours depending on the complexity of ... normal activities in seven to 10 days. Follow-up ultrasounds will be performed frequently after the TIPS ...

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  5. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... of an effect than open surgical bypass on future liver transplantation surgery because the abdomen has not ... TIPS. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient Center This page ...

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  9. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Contrast Materials Venography Images related to Transjugular Intrahepatic Portosystemic Shunt (TIPS) Sponsored ...

  10. Search Tips: MedlinePlus

    Science.gov (United States)

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

  11. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... to the heart while avoiding the liver. TIPS may successfully reduce internal bleeding in the stomach and ... conditions, allergies and medications you’re taking. You may be advised to stop taking aspirin, nonsteroidal anti- ...

  12. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... risks. Other possible complications of the procedure include: fever muscle stiffness in the neck bruising on the ... filtered out by the liver. The TIPS may cause too much of these substances to bypass the ...

  13. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  14. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... system. This pressure buildup can cause blood to flow backward from the liver into the veins of ... does the procedure work? A TIPS reroutes blood flow in the liver and reduces abnormally high blood ...

  15. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... liver back to the heart. top of page How should I prepare? You should report to your ... heart beat and blood pressure. top of page How does the procedure work? A TIPS reroutes blood ...

  16. Computerized automatic tip scanning operation

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  17. Tips to Prevent Tick Bites

    Science.gov (United States)

    Using the right insect repellent and other preventive actions can discourage ticks, mosquitoes, and other biting insects from landing on you. Tips include avoiding tick habitats and minimizing exposed skin.

  18. Tips to Prevent Mosquito Bites

    Science.gov (United States)

    Using the right insect repellent and other preventive actions can discourage mosquitoes from landing on you. Tips include removing mosquito habitats such as standing water, minimizing exposed skin, and staying indoors while mosquitoes are most active.

  19. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  20. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

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

  1. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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

  2. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

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    Full Text Available ... of page What are some common uses of the procedure? A TIPS is used to treat the ... during the procedure. top of page What does the equipment look like? In this procedure, x-ray ...

  3. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... is completed. top of page What are the benefits vs. risks? Benefits A TIPS is designed to produce the same ... urgent intervention heart arrhythmias or congestive heart failure radiation injury to the skin is a rare complication ( ...

  4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... local anesthetic medications, general anesthesia or to contrast materials containing iodine (sometimes referred to as "dye" or " ... the placement of the TIPS stent, a contrast material will be injected in the hepatic vein to ...

  5. Automated Tracking of Root for Confocal Time-lapse Imaging of Cellular Processes.

    Science.gov (United States)

    Doumane, Mehdi; Lionnet, Claire; Bayle, Vincent; Jaillais, Yvon; Caillaud, Marie-Cécile

    2017-04-20

    Here we describe a protocol that enables to automatically perform time-lapse imaging of growing root tips for several hours. Plants roots expressing fluorescent proteins or stained with dyes are imaged while they grow using automatic movement of the microscope stage that compensates for root growth and allows to follow a given region of the root over time. The protocol makes possible the image acquisition of multiple growing root tips, therefore increasing the number of recorded mitotic events in a given experiment. The protocol also allows the visualization of more than one fluorescent protein or dye simultaneously, using multiple channel acquisition. We particularly focus on imaging of cytokinesis in Arabidopsis root tip meristem, but this protocol is also suitable to follow root hair growth, pollen tube growth, and other regions of root over time, in various plant species. It may as well be amendable to automatically track non-plant structures with an apical growth.

  6. Tip model of cold fission

    International Nuclear Information System (INIS)

    Goennenwein, F.; Boersig, B.

    1991-01-01

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

  7. Nonhazardous Urine Pretreatment Method

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.

    2012-01-01

    A method combines solid phase acidification with two non-toxic biocides to prevent ammonia volatilization and microbial proliferation. The safe, non-oxidizing biocide combination consists of a quaternary amine and a food preservative. This combination has exhibited excellent stabilization of both acidified and unacidified urine. During pretreatment tests, composite urine collected from donors was challenged with a microorganism known to proliferate in urine, and then was processed using the nonhazardous urine pre-treatment method. The challenge microorganisms included Escherichia coli, a common gram-negative bacteria; Enterococcus faecalis, a ureolytic gram-positive bacteria; Candida albicans, a yeast commonly found in urine; and Aspergillus niger, a problematic mold that resists urine pre-treatment. Urine processed in this manner remained microbially stable for over 57 days. Such effective urine stabilization was achieved using non-toxic, non-oxidizing biocides at higher pH (3.6 to 5.8) than previous methods in use or projected for use aboard the International Space Station (ISS). ISS urine pretreatment methods employ strong oxidants including ozone and hexavalent chromium (Cr(VI)), a carcinogenic material, under very acidic conditions (pH = 1.8 to 2.4). The method described here offers a much more benign chemical environment than previous pretreatment methods, and will lower equivalent system mass (ESM) by reducing containment volume and mass, system complexity, and crew time needed to handle pre-treatment chemicals. The biocides, being non-oxidizing, minimize the potential for chemical reactions with urine constituents to produce volatile, airborne contaminants such as cyanogen chloride. Additionally, the biocides are active under significantly less acidic conditions than those used in the current system, thereby reducing the degree of required acidification. A simple flow-through solid phase acidification (SPA) bed is employed to overcome the natural buffering

  8. Immobilization of aluminum with mucilage secreted by root cap and root border cells is related to aluminum resistance in Glycine max L.

    Science.gov (United States)

    Cai, Miaozhen; Wang, Ning; Xing, Chenghua; Wang, Fangmei; Wu, Kun; Du, Xing

    2013-12-01

    The root cap and root border cells (RBCs) of most plant species produced pectinaceous mucilage, which can bind metal cations. In order to evaluate the potential role of root mucilage on aluminum (Al) resistance, two soybean cultivars differing in Al resistance were aeroponic cultured, the effects of Al on root mucilage secretion, root growth, contents of mucilage-bound Al and root tip Al, and the capability of mucilage to bind Al were investigated. Increasing Al concentration and exposure time significantly enhanced mucilage excretion from both root caps and RBCs, decreased RBCs viability and relative root elongation except roots exposed to 400 μM Al for 48 h in Al-resistant cultivar. Removal of root mucilage from root tips resulted in a more severe inhibition of root elongation. Of the total Al accumulated in root, mucilage accounted 48-72 and 12-27 %, while root tip accounted 22-52 and 73-88 % in Al-resistant and Al-sensitive cultivars, respectively. A (27)Al nuclear magnetic resonance spectrum of the Al-adsorbed mucilage showed Al tightly bound to mucilage. Higher capacity to exclude Al in Al-resistant soybean cultivar is related to the immobilization and detoxification of Al by the mucilage secreted from root cap and RBCs.

  9. Tonoplast aquaporins facilitate lateral root emergence

    DEFF Research Database (Denmark)

    Reinhardt, Hagen; Hachez, Charles; Bienert, Manuela Désirée

    2016-01-01

    mutants showed no or minor reduction in growth of the main root. This phenotype was due to the retardation of LRP emergence. Live cell imaging revealed that tight spatiotemporal control of TIP abundance in the tonoplast of the different LRP cells is pivotal to mediating this developmental process. While...

  10. Influence of temperature and rooting-promoter on the formation of root-primodia and on the rooting of chrysanthemum cuttings under storage

    International Nuclear Information System (INIS)

    Nishio, J.; Fukuda, M.

    1998-01-01

    In order to promote rooting for direct planting cuttings in a lighting cultivation of chrysanthemum, we clarified the effects of light, temperature and term of storage of the cuttings, and analyzed ways of using rooting promoters as a pre-treatment of cuttings for root-primodia formation and rooting. Light as a pre-treatment had little effect, so it seemed to be not necessary for the formation of root primodia. The formation of the root-primodia was most hastened at 25 degrees C; inversely, it was slowed down at low temperatures, that is, the root-primodia were formed in four days at 25 degrees C, five days at 20 degrees C, and seven days at 15 degrees C. With the use of rooting promoters as a pre-treatment for the rooting of cuttings, the root-primodia were formed faster when the whole of cuttings were dipped in 40 mg/L solution of indelebutyric acid (IBA) than when the base of cuttings were dipped or sprayed 400 mg/L solution of IBA. It was appropriate that cuttings were dipped in IBA then put in in plastic-pots (7.5cm) vertically, packed in polyethylene-bags and stored in a corrugated carton box

  11. The cytoskeleton in plant cell growth: lessons from root hairs

    NARCIS (Netherlands)

    Ketelaar, M.J.; Emons, A.M.C.

    2001-01-01

    In this review, we compare expansion of intercalary growing cells, in which growth takes place over a large surface, and root hairs, where expansion occurs at the tip only. Research that pinpoints the role of the cytoskeleton and the cytoplasmic free calcium in both root hairs and intercalary

  12. Assessment of root surfaces of apicected teeth: A scanning electron ...

    African Journals Online (AJOL)

    Objectives: The aim of this study was to determine the apical surface characteristics and presence of dental cracks in single‑rooted premolars, resected 3.0 mm from the root apex, using the Er: YAG laser, tungsten carbide bur, and diamond‑coated tip, by scanning electron microscopy (SEM). Experimental design: Thirty ...

  13. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order based fine root morphology and biomass?

    Directory of Open Access Journals (Sweden)

    Petra eKubisch

    2015-02-01

    Full Text Available While most temperate broad-leaved tree species form ectomycorrhizal (EM symbioses, a few species have arbuscular mycorrhizas (AM. It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus and Tilia searching for principal differences between EM and AM trees. We further assessed the evidence of convergence or divergence in root traits among the six co-occurring species. Eight fine root morphological and chemical traits were investigated in root segments of the first to fourth root order in three different soil depths and the relative importance of the factors root order, tree species and soil depth for root morphology was determined. Root order was more influential than tree species while soil depth had only a small effect on root morphology All six species showed similar decreases in specific root length and specific root area from the 1st to the 4th root order, while the species patterns differed considerably in root tissue density, root N concentration, and particularly with respect to root tip abundance. Most root morphological traits were not significantly different between EM and AM species (except for specific root area that was larger in AM species, indicating that mycorrhiza type is not a key factor influencing fine root morphology in these species. The order-based root analysis detected species differences more clearly than the simple analysis of bulked fine root mass. Despite convergence in important root traits among AM and EM species, even congeneric species may differ in certain fine root morphological traits. This suggests that, in general, species identity has a larger influence on fine root morphology than mycorrhiza type.

  14. Root patterning

    NARCIS (Netherlands)

    Scheres, Ben; Laskowski, Marta

    2016-01-01

    The mechanisms that pattern lateral root primordial are essential for the elaboration of root system architecture, a trait of key importance for future crop breeding. But which are most important: periodic or local cues? In this issue of Journal of Experimental Botany (pages 1411-1420), Kircher

  15. Biomass shock pretreatment

    Science.gov (United States)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  16. Performance assessment of novel side firing safe tips for endodontic applications

    Science.gov (United States)

    George, Roy; Walsh, Laurence J.

    2011-04-01

    During root canal or periodontal treatment, directing laser energy onto the walls of the root canal is essential for effective disinfection. This study assessed the performance of four different fiber modifications that have increased lateral emission, including three designs with safe tips to reduce irradiation directed toward the root apex. Free-running pulsed infrared lasers (Nd:YAG, Er:YAG, and Er,Cr:YSGG) and a diode laser (980 nm) were used in combination with plain ended (forward emitting) laser fibers; conical laser fibers, side firing honeycomb pattern fibers without a safe end; honeycomb fibers with silver coated ends, conical fibers with selectively abraded tips, and selectively abraded honeycomb fibers with silver coated tips (20 fibers for each laser type). Laser emissions forward and laterally were measured, and digital photographs and thermally sensitive paper used to record the emission profiles. Thermochromic dyes painted onto the root surface of an extracted tooth were used to explore the distribution of laser energy with different tips designs. All three safe tipped ends gave reduced emissions in the forward direction (range 17-59%), but had similar lateral emission characteristics. Fiber designs with reduced forward emission may be useful for various dental laser procedures.

  17. Influence of electrical fields and asymmetric application of mucilage on curvature of primary roots of Zea mays

    Science.gov (United States)

    Marcum, H.; Moore, R.

    1990-01-01

    Primary roots of Zea mays cv. Yellow Dent growing in an electric field curve towards the anode. Roots treated with EDTA and growing in electric field do not curve. When root cap mucilage is applied asymmetrically to tips of vertically-oriented roots, the roots curve toward the mucilage. Roots treated with EDTA curve toward the side receiving mucilage and toward blocks containing 10 mM CaCl2, but not toward "empty" agar blocks or the cut surfaces of severed root tips. These results suggest that 1) free calcium (Ca) is necessary for root electrotropism, 2) mucilage contains effector(s) that induce gravitropiclike curvature, and 3) mucilage can replace gravitropic effectors chelated by EDTA. These results are consistent with the hypothesis that the downward movement of gravitropic effectors to the lower sides of tips of horizontally-oriented roots occurs at least partially in the apoplast.

  18. Nanobits: customizable scanning probe tips

    DEFF Research Database (Denmark)

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

    2009-01-01

    We present here a proof-of-principle study of scanning probe tips defined by planar nanolithography and integrated with AFM probes using nanomanipulation. The so-called 'nanobits' are 2-4 mu m long and 120-150 nm thin flakes of Si3N4 or SiO2, fabricated by electron beam lithography and standard...... or dislocation of the tips of the nanobit after several scans. This approach allows an unprecedented freedom in adapting the shape and size of scanning probe tips to the surface topology or to the specific application....... silicon processing. Using a microgripper they were detached from an array and fixed to a standard pyramidal AFM probe or alternatively inserted into a tipless cantilever equipped with a narrow slit. The nanobit-enhanced probes were used for imaging of deep trenches, without visible deformation, wear...

  19. ZBrush Professional Tips and Techniques

    CERN Document Server

    Gaboury, Paul

    2012-01-01

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

  20. Office 2010 Visual Quick Tips

    CERN Document Server

    Gunter, Sherry Kinkoph

    2010-01-01

    Get more done in Office 2010 in less time with these Quick Tips!. Whether you're new to Microsoft Office or updating from older versions, this is the perfect resource to get you quickly up to speed on Office 2010. Every application is covered, including Word, Excel, PowerPoint, Outlook, and Publisher. Full-color screenshots and numbered steps clearly explain dozens of features and functions-while quick shortcuts, tips, and tricks help you save time and boost productivity. You'll also find great new ways to access and use some Office apps right from the Web.: Walks you through dozens of new fea

  1. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost......-an ectodermal tissue layer (Malassez′s epithelium), a middle layer-composed by the collagen-mesodermal tissue layer, and an innermost root-close innervation layer. Abnormalities in one of these tissue layers are thought to cause inflammatory processes in the periodontal membrane comparable to inflammatory...

  2. Licorice Root

    Science.gov (United States)

    ... T U V W X Y Z Licorice Root Share: On This Page Background How Much Do ... This fact sheet provides basic information about licorice root—common names, usefulness and safety, and resources for ...

  3. Study of binding properties of lanthanum to wheat roots by INAA

    International Nuclear Information System (INIS)

    Zhang, Z.Y.; Li, F.L.; Xiao, H.Q.; Chai, Z.F.; Xu, L.; Liu, N.

    2004-01-01

    Chemical behavior of lanthanum in root tips excized from wheat seedlings growing at both promotional and inhibitory levels of LaCl 3 in culture solutions was investigated by a sequential leaching procedure combined with instrumental neutron activation analysis. The results indicate that most of La exists in non-exchangeable species and the binding of La 3+ to the root tips is extremely stable. The root tips during growing at the inhibitory level of LaCl 3 absorb much more La than those at the promotional level. However, the La proportion in each fraction is similar for both groups. (author)

  4. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions

    Directory of Open Access Journals (Sweden)

    Alexander Martin Paya

    2015-04-01

    Full Text Available Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen and Picea mariana (black spruce seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for two months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals and paired seedlings (inter- or intra-specific, than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

  5. The tip of the iceberg

    DEFF Research Database (Denmark)

    Bjørst, Lill Rastad

    2010-01-01

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

  6. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

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

  7. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... pressure. top of page How does the procedure work? A TIPS reroutes blood flow in the liver and reduces abnormally high blood pressure in the veins of the stomach, esophagus, bowel and liver, reducing the risk of bleeding from enlarged veins across the esophagus ...

  8. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available ... failure is severe, a TIPS may not be the best use and a different procedure may be needed to control your symptoms. They are also at risk for encephalopathy , which is an alteration of normal brain function that can lead to confusion. This is ...

  9. Food Allergy: Tips to Remember

    Science.gov (United States)

    ... or get better on their own. Outgrowing Food Allergies Most children outgrow their allergies to cow’s milk, egg, soy ... can help you learn when you or your child’s food allergies are resolving with time. Healthy Tips • Always ask ...

  10. Transjugular Intrahepatic Portosystemic Shunt (TIPS)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... limitations of TIPS? Patients with more advanced liver disease are at greater risk for worsening liver failure ...

  11. Assigning Effective Homework. Classroom Tips

    Science.gov (United States)

    American Federation of Teachers (NJ), 2010

    2010-01-01

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

  12. Predicting casualties implied by TIPs

    Science.gov (United States)

    Trendafiloski, G.; Wyss, M.; Wyss, B. M.

    2009-12-01

    When an earthquake is predicted, forecast, or expected with a higher than normal probability, losses are implied. We estimated the casualties (fatalities plus injured) that should be expected if earthquakes in TIPs (locations of Temporarily Increased Probability of earthquakes) defined by Kossobokov et al. (2009) should occur. We classified the predictions of losses into the categories red (more than 400 fatalities or more than 1,000 injured), yellow (between 100 and 400 fatalities), green (fewer than 100 fatalities), and gray (undetermined). TIPs in Central Chile, the Philippines, Papua, and Taiwan are in the red class, TIPs in Southern Sumatra, Nicaragua, Vanatu, and Honshu in the yellow class, and TIPs in Tonga, Loyalty Islands, Vanatu, S. Sandwich Islands, Banda Sea, and the Kuriles, are classified as green. TIPs where the losses depend moderately on the assumed point of major energy release were classified as yellow; TIPs such as in the Talaud Islands and in Tonga, where the losses depend very strongly on the location of the epicenter, were classified as gray. The accuracy of loss estimates after earthquakes with known hypocenter and magnitude are affected by uncertainties in transmission and soil properties, the composition of the building stock, the population present, and the method by which the numbers of casualties are calculated. In the case of TIPs, uncertainties in magnitude and location are added, thus we calculate losses for a range of these two parameters. Therefore, our calculations can only be considered order of magnitude estimates. Nevertheless, our predictions can come to within a factor of two of the observed numbers, as in the case of the M7.6 earthquake of October 2005 in Pakistan that resulted in 85,000 fatalities (Wyss, 2005). In subduction zones, the geometrical relationship between the earthquake source capable of a great earthquake and the population is clear because there is only one major fault plane available, thus the epicentral

  13. Actin polymerization drives polar growth in Arabidopsis root hair cells.

    Science.gov (United States)

    Vazquez, Luis Alfredo Bañuelos; Sanchez, Rosana; Hernandez-Barrera, Alejandra; Zepeda-Jazo, Isaac; Sánchez, Federico; Quinto, Carmen; Torres, Luis Cárdenas

    2014-01-01

    In plants, the actin cytoskeleton is a prime regulator of cell polarity, growth, and cytoplasmic streaming. Tip growth, as observed in root hairs, caulonema, and pollen tubes, is governed by many factors, including calcium gradients, exocytosis and endocytosis, reactive oxygen species, and the cytoskeleton. Several studies indicate that the polymerization of G-actin into F-actin also contributes to tip growth. The structure and function of F-actin within the apical dome is variable, ranging from a dense meshwork to sparse single filaments. The presence of multiple F-actin structures in the elongating apices of tip-growing cells suggests that this cytoskeletal array is tightly regulated. We recently reported that sublethal concentrations of fluorescently labeled cytochalasin could be used to visualize the distribution of microfilament plus ends using fluorescence microscopy, and found that the tip region of the growing root hair cells of a legume plant exhibits a clear response to the nodulation factors secreted by Rhizobium. (1) In this current work, we expanded our analysis using confocal microscopy and demonstrated the existence of highly dynamic fluorescent foci along Arabidopsis root hair cells. Furthermore, we show that the strongest fluorescence signal accumulates in the tip dome of the growing root hair and seems to be in close proximity to the apical plasma membrane. Based on these findings, we propose that actin polymerization within the dome of growing root hair cells regulates polar growth.

  14. Mini-flared Kelman tip, reverse tip, and sidewinder tip with torsional phaco: a prospective randomized comparative study

    Directory of Open Access Journals (Sweden)

    Wilson Takashi Hida

    2015-02-01

    Full Text Available Purpose: To compare the efficiency of surgical procedures using three phaco tip designs in torsional phacoemulsification using the bevel-down technique. Methods: In this prospective, comparative, masked study, patients were randomly assigned to have torsional coaxial microincision cataract surgery using the mini-flared 45-degree Kelman tip, reversed mini-flared 30-degree Kelman tip, or Sidewinder 30-degree Kelman tip. Clinical measurements included preoperative and 3-month postoperative corrected distance visual acuity (CDVA, endothelial cell counts (ECC, and preoperative and 1-day postoperative central corneal thickness (CCT. Intraoperative measurements included phaco time, torsional time, aspiration time, case time, cumulative dissipated energy (CDE, and balanced salt solution volume (BSS. Results: The study evaluated 150 eyes of 150 patients. Intraoperatively, there was no statistically significant difference in cumulative dissipated energy, case time, torsional time, and aspiration time between the three tip configurations. However, less phaco time was used with the mini-flared 45-degree Kelman tip (p=0.02 than that with the Sidewinder 30-degree Kelman tip or reversed mini-flared 30-degree Kelman tip. The mini-flared 45-degree Kelman tip and the reversed mini-flared 30-degree Kelman tip required significantly less balanced salt solution volume than that required by the Sidewinder 30-degree Kelman tip (p=0.009. There was no statistically significant difference in corrected distance visual acuity and endothelial cell counts between tips 3 months postoperatively (p>0.05. Conclusion: All three tips were effective with no intraoperative complications. When using torsional phacoemulsification through microincisions and the prefracture technique with the bevel-down technique, the mini-flared 45-degree Kelman tip required a lower mean phaco time than the reversed mini-flared 30-degree Kelman tip and the Sidewinder 30-degree Kelman tip.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-15

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  17. Parenting Tips: How to Improve Toddler Behavior

    Science.gov (United States)

    ... issues. To encourage listening and cooperation, follow these parenting tips. By Mayo Clinic Staff Life can be ... and a degree of routine. Consider these practical parenting tips. Make sure your displays of affection for ...

  18. Tips for Good Oral Health during Pregnancy

    Science.gov (United States)

    Tips for Good Oral Health During Pregnancy B elow are tips for taking care of your oral health while you are pregnant. Getting oral health care, practicing good oral hygiene, eating healthy foods, ...

  19. School Avoidance: Tips for Concerned Parents

    Science.gov (United States)

    ... Email Print Share School Avoidance: Tips for Concerned Parents Page Content ​School avoidance – sometimes called school refusal ... school bully) Actual physical harm Tips for Concerned Parents: As a first step, the management of school ...

  20. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-15

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

  1. Evaluation of apical preparations performed with ultrasonic diamond and stainless steel tips at different intensities using a scanning electron microscope in endodontic surgery.

    Science.gov (United States)

    Rodríguez-Martos, Ramón; Torres-Lagares, Daniel; Castellanos-Cosano, Lizett; Serrera-Figallo, María-Angeles; Segura-Egea, Juan-José; Gutierrez-Perez, Jose-Luis

    2012-11-01

    The objective of our study is to analyse (with the help of scanning electron microscopes) the quality of the dental root surface and the appearance of dental cracks after performing apical preparations using two different types of ultrasonic tips. We used 32 single-rooted teeth that underwent a root canal and apical resection. Afterwards, the teeth were divided into 4 groups of 8 teeth each, with preparations of the apical cavities in the following manner: Group 1: stainless steel ultrasonic tip at 33 KHz. Group 2: stainless steel ultrasonic tip at 30 KHz. Group 3: diamond ultrasonic tip at 30 KHz. Group 4: diamond ultrasonic tip at 33 KHz. The quality of the root surface and the presence of cracks were evaluated by one single observer using a scanning electron microscope. All of the teeth in our study had cracks after the apical preparations. The mean number of cracks per tooth ranged between 6. ± 1.9 (group 1) and 3.5 ± 2.4 (group 4), with a significantly higher number found in the groups that used stainless steel tips (P=.03). The types of cracks produced involved: 8 complete cracks (4.5%), 167 incomplete cracks (94.4%), and 2 intradentinal cracks (1.1%), with no significant differences observed between the different frequencies used for each group. Stainless steel ultrasonic tips provoked a larger number of cracks than diamond tips. The frequency of vibration used did not have any effect on the number of cracks found.

  2. Effects of nutrient heterogeneity and competition on root architecture of spruce seedlings: implications for an essential feature of root foraging.

    Directory of Open Access Journals (Sweden)

    Hongwei Nan

    Full Text Available BACKGROUND: We have limited understanding of root foraging responses when plants were simultaneously exposed to nutrient heterogeneity and competition, and our goal was to determine whether and how plants integrate information about nutrients and neighbors in root foraging processes. METHODOLOGY/PRINCIPAL FINDINGS: The experiment was conducted in split-containers, wherein half of the roots of spruce (Picea asperata seedlings were subjected to intraspecific root competition (the vegetated half, while the other half experienced no competition (the non-vegetated half. Experimental treatments included fertilization in the vegetated half (FV, the non-vegetated half (FNV, and both compartments (F, as well as no fertilization (NF. The root architecture indicators consisted of the number of root tips over the root surface (RTRS, the length percentage of diameter-based fine root subclasses to total fine root (SRLP, and the length percentage of each root order to total fine root (ROLP. The target plants used novel root foraging behaviors under different combinations of neighboring plant and localized fertilization. In addition, the significant increase in the RTRS of 0-0.2 mm fine roots after fertilization of the vegetated half alone and its significant decrease in fertilizer was applied throughout the plant clearly showed that plant root foraging behavior was regulated by local responses coupled with systemic control mechanisms. CONCLUSIONS/SIGNIFICANCE: We measured the root foraging ability for woody plants by means of root architecture indicators constructed by the roots possessing essential nutrient uptake ability (i.e., the first three root orders, and provided new evidence that plants integrate multiple forms of environmental information, such as nutrient status and neighboring competitors, in a non-additive manner during the root foraging process. The interplay between the responses of individual root modules (repetitive root units to localized

  3. Endocardial tip cells in the human embryo - facts and hypotheses.

    Directory of Open Access Journals (Sweden)

    Mugurel C Rusu

    Full Text Available Experimental studies regarding coronary embryogenesis suggest that the endocardium is a source of endothelial cells for the myocardial networks. As this was not previously documented in human embryos, we aimed to study whether or not endothelial tip cells could be correlated with endocardial-dependent mechanisms of sprouting angiogenesis. Six human embryos (43-56 days were obtained and processed in accordance with ethical regulations; immunohistochemistry was performed for CD105 (endoglin, CD31, CD34, α-smooth muscle actin, desmin and vimentin antibodies. Primitive main vessels were found deriving from both the sinus venosus and aorta, and were sought to be the primordia of the venous and arterial ends of cardiac microcirculation. Subepicardial vessels were found branching into the outer ventricular myocardium, with a pattern of recruiting α-SMA+/desmin+ vascular smooth muscle cells and pericytes. Endothelial sprouts were guided by CD31+/CD34+/CD105+/vimentin+ endothelial tip cells. Within the inner myocardium, we found endothelial networks rooted from endocardium, guided by filopodia-projecting CD31+/CD34+/CD105+/ vimentin+ endocardial tip cells. The myocardial microcirculatory bed in the atria was mostly originated from endocardium, as well. Nevertheless, endocardial tip cells were also found in cardiac cushions, but they were not related to cushion endothelial networks. A general anatomical pattern of cardiac microvascular embryogenesis was thus hypothesized; the arterial and venous ends being linked, respectively, to the aorta and sinus venosus. Further elongation of the vessels may be related to the epicardium and subepicardial stroma and the intramyocardial network, depending on either endothelial and endocardial filopodia-guided tip cells in ventricles, or mostly on endocardium, in atria.

  4. Injector tip for an internal combustion engine

    Science.gov (United States)

    Shyu, Tsu Pin; Ye, Wen

    2003-05-20

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

  5. How do roots elongate in a structured soil?

    Science.gov (United States)

    Jin, Kemo; Shen, Jianbo; Ashton, Rhys W; Dodd, Ian C; Parry, Martin A J; Whalley, William R

    2013-11-01

    In this review, we examine how roots penetrate a structured soil. We first examine the relationship between soil water status and its mechanical strength, as well as the ability of the soil to supply water to the root. We identify these as critical soil factors, because it is primarily in drying soil that mechanical constraints limit root elongation. Water supply to the root is important because root water status affects growth pressures and root stiffness. To simplify the bewildering complexity of soil-root interactions, the discussion is focused around the special cases of root elongation in soil with pores much smaller than the root diameter and the penetration of roots at interfaces within the soil. While it is often assumed that the former case is well understood, many unanswered questions remain. While low soil-root friction is often viewed as a trait conferring better penetration of strong soils, it may also increase the axial pressure on the root tip and in so doing reduce the rate of cell division and/or expansion. The precise trade-off between various root traits involved in root elongation in homogeneous soil remains to be determined. There is consensus that the most important factors determining root penetration at an interface are the angle at which the root attempts to penetrate the soil, root stiffness, and the strength of the soil to be penetrated. The effect of growth angle on root penetration implicates gravitropic responses in improved root penetration ability. Although there is no work that has explored the effect of the strength of the gravitropic responses on penetration of hard layers, we attempt to outline possible interactions. Impacts of soil drying and strength on phytohormone concentrations in roots, and consequent root-to-shoot signalling, are also considered.

  6. Root (Botany)

    Science.gov (United States)

    Robert R. Ziemer

    1981-01-01

    Plant roots can contribute significantly to the stability of steep slopes. They can anchor through the soil mass into fractures in bedrock, can cross zones of weakness to more stable soil, and can provide interlocking long fibrous binders within a weak soil mass. In deep soil, anchoring to bedrock becomes negligible, and lateral reinforcement predominates

  7. Clean Firetube Boiler Waterside Heat Transfer Surfaces, Energy Tips: STEAM, Steam Tip Sheet #7 (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    A steam energy tip sheet for the Advanced Manufacturing Office (AMO). The prevention of scale formation in firetube boilers can result in substantial energy savings. Scale deposits occur when calcium, magnesium, and silica, commonly found in most water supplies, react to form a continuous layer of material on the waterside of the boiler heat exchange tubes. Scale creates a problem because it typically possesses a thermal conductivity, an order of magnitude less than the corresponding value for bare steel. Even thin layers of scale serve as an effective insulator and retard heat transfer. The result is overheating of boiler tube metal, tube failures, and loss of energy efficiency. Fuel consumption may increase by up to 5% in firetube boilers because of scale. The boilers steam production may be reduced if the firing rate cannot be increased to compensate for the decrease in combustion efficiency. Energy losses as a function of scale thickness and composition are given. Any scale in a boiler is undesirable. The best way to deal with scale is not to let it form in the first place. Prevent scale formation by: (1) Pretreating of boiler makeup water (using water softeners, demineralizers, and reverse osmosis to remove scale-forming minerals); (2) Injecting chemicals into the boiler feedwater; and (3) Adopting proper boiler blowdown practices.

  8. Plant root and shoot dynamics during subsurface obstacle interaction

    Science.gov (United States)

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

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

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

    NARCIS (Netherlands)

    Scheres, Ben; Krizek, Beth A.

    2018-01-01

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

  10. Vitality and chemistry of roots of red spruce in forest floors of stands with a gradient of soil Al/Ca ratios in the northeastern United States

    Science.gov (United States)

    Philip M. Wargo; Kristiina Vogt; Daniel Vogt; Quintaniay Holifield; Joel Tilley; Gregory Lawrence; Mark David

    2003-01-01

    Number of living root tips per branch, percent dead roots, percent mycorrhizae and mycorrhizal morphotype, response of woody roots to wounding and colonization by fungi, and concentrations of starch, soluble sugars, phenols, percent C and N and C/N ratio, and Al, Ca, Fe, K, Mg, Mn, and P were measured for 2 consecutive years in roots of red spruce (Picea...

  11. Root disease management guidebook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Forest tree root pathogens are widespread throughout all forested ecosystems in British Columbia. This guidebook provides a background to forest root disease management (including why, where, and how to manage root disease) and describes the necessary tools for managing root disease. It includes a review of the distribution of major root diseases in the province, host susceptibility and symptomology, and root disease and stand dynamics. The tools described include disease hazard and risk assessment, stratification surveys, and treatment methods. The major root diseases covered in the guide are Armillaria root disease, laminated root rot, Tomentosus root rot, blackstain root disease, and Annosus root disease.

  12. In vitro performance of DIAGNOdent laser fluorescence device for dental calculus detection on human tooth root surfaces

    Directory of Open Access Journals (Sweden)

    Thomas E. Rams

    2017-10-01

    Conclusions: Excellent intra- and inter-examiner reproducibility of autofluorescence intensity measurements was obtained with the DIAGNOdent laser fluorescence device on human tooth roots. Calculus-positive root surfaces exhibited significantly greater DIAGNOdent laser autofluorescence than calculus-free tooth roots, even with the laser probe tip directed parallel to root surfaces. These findings provide further in vitro validation of the potential utility of a DIAGNOdent laser fluorescence device for identifying dental calculus on human tooth root surfaces.

  13. Dual-flow-RootChip reveals local adaptations of roots towards environmental asymmetry at the physiological and genetic levels.

    Science.gov (United States)

    Stanley, Claire E; Shrivastava, Jagriti; Brugman, Rik; Heinzelmann, Elisa; van Swaay, Dirk; Grossmann, Guido

    2018-02-01

    Roots grow in highly dynamic and heterogeneous environments. Biological activity as well as uneven nutrient availability or localized stress factors result in diverse microenvironments. Plants adapt their root morphology in response to changing environmental conditions, yet it remains largely unknown to what extent developmental adaptations are based on systemic or cell-autonomous responses. We present the dual-flow-RootChip, a microfluidic platform for asymmetric perfusion of Arabidopsis roots to investigate root-environment interactions under simulated environmental heterogeneity. Applications range from investigating physiology, root hair development and calcium signalling upon selective exposure to environmental stresses to tracing molecular uptake, performing selective drug treatments and localized inoculations with microbes. Using the dual-flow-RootChip, we revealed cell-autonomous adaption of root hair development under asymmetric phosphate (Pi) perfusion, with unexpected repression in root hair growth on the side exposed to low Pi and rapid tip-growth upregulation when Pi concentrations increased. The asymmetric root environment further resulted in an asymmetric gene expression of RSL4, a key transcriptional regulator of root hair growth. Our findings demonstrate that roots possess the capability to locally adapt to heterogeneous conditions in their environment at the physiological and transcriptional levels. Being able to generate asymmetric microenvironments for roots will help further elucidate decision-making processes in root-environment interactions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  14. Prenylated stilbenes from peanut root mucilage.

    Science.gov (United States)

    Sobolev, Victor S; Potter, Thomas L; Horn, Bruce W

    2006-01-01

    Seven prenylated stilbenes were identified by combined HPLC-PAD-APCI/MSn analysis of an extract of mucilage isolated from peanut (Arachis hypogaea L.) root tips. The principal constituent was assigned the structure 4-(3-methyl-but-1-enyl)-3, 5-dimethoxy-4'-hydroxy-trans-stilbene. The common name mucilagin A is proposed for this novel compound. Its concentration in the mucilage was estimated at 250 microg/g (wet weight basis). The large body of literature on the anti-microbial properties of plant-derived stilbenes suggests that compounds detected in peanut mucilage may play a role in regulating root-soil pathogen interactions.

  15. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    Directory of Open Access Journals (Sweden)

    Lorenzo Pedrotti

    Full Text Available Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

  16. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    Science.gov (United States)

    Pedrotti, Lorenzo; Mueller, Martin J; Waller, Frank

    2013-01-01

    Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

  17. Windows 8 visual quick tips

    CERN Document Server

    McFedries, Paul

    2012-01-01

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

  18. Twitter Tips, Tricks, and Tweets

    CERN Document Server

    McFedries, Paul

    2010-01-01

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

  19. Rebleeding rates following TIPS for variceal hemorrhage in the Viatorr era: TIPS alone versus TIPS with variceal embolization.

    Science.gov (United States)

    Gaba, Ron C; Bui, James T; Cotler, Scott J; Kallwitz, Eric R; Mengin, Olga T; Martinez, Brandon K; Berkes, Jaime L; Carrillo, Tami C; Knuttinen, M Grace; Owens, Charles A

    2010-08-06

    To compare rebleeding rates following treatment of variceal hemorrhage with TIPS alone versus TIPS with variceal embolization in the covered stent-graft era. In this retrospective study, 52 patients (M:F 29:23, median age 52 years) with hepatic cirrhosis and variceal hemorrhage underwent TIPS insertion between 2003 and 2008. Median Child-Pugh and MELD scores were 8.5 and 13.5. Generally, 10-mm diameter TIPS were created using covered stent-grafts (Viatorr; W.L. Gore and Associates, Flagstaff, AZ). A total of 37 patients underwent TIPS alone, while 15 patients underwent TIPS with variceal embolization. The rates of rebleeding and survival were compared. All TIPS were technically successful. Median portosystemic pressure gradient reductions were 13 versus 11 mmHg in the embolization and non-embolization groups. There were no statistically significant differences in Child-Pugh and MELD score, or portosystemic pressure gradients between each group. A trend toward increased rebleeding was present in the non-embolization group, where 8/37 (21.6%) patients rebled while 1/15 (6.7%) patients in the TIPS with embolization group rebled (P = 0.159) during median follow-up periods of 199 and 252 days (P = 0.374). Rebleeding approached statistical significance among patients with acute hemorrhage, where 8/32 (25%) versus 0/14 (0%) rebled in the non-embolization and embolization groups (P = 0.055). A trend toward increased bleeding-related mortality was seen in the non-embolization group (P = 0.120). TIPS alone showed a high incidence of rebleeding in this series, whereas TIPS with variceal embolization resulted in reduced recurrent hemorrhage. The efficacy of embolization during TIPS performed for variceal hemorrhage versus TIPS alone should be further compared with larger prospective randomized trials.

  20. Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study.

    Science.gov (United States)

    Kasam, Swetha; Mariswamy, Annapoorna Ballagere

    2016-06-01

    Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment. To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various endodontic files. Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was performed. The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in mm(2). Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive statistics, ANOVA and Scheffe's post hoc test through SPSS for windows (v 16.0). The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (pretreatment tip proved to be an efficient method of removing obturated

  1. Locally Finite Root Supersystems

    OpenAIRE

    Yousofzadeh, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  2. Effect of phorbol derivatives and staurosporine on gravitropic response of primary root of maize

    Energy Technology Data Exchange (ETDEWEB)

    Mulkey, T.J.; Kim, S.Y. (Indiana State Univ., Terre Haute (United States)); Lee, J.S. (Ewha Womans Univ., Seoul (Korea))

    1991-05-01

    Time-lapse videography and computer-based, video image digitization were used to examine the effects of phorbol derivatives (phorbol 12-myristate 13-acetate, TPA; phorbol 12-myristate 13-acetate 4-O-methyl ether, mTPA) and staurosporine on the kinetics of gravicurvature of primary roots of maize (Zea mays L., Pioneer 3343 and Golden Cross Bantam). Pretreatment of roots with TPA (3 hr, 1 {mu}M) decreases the time lag prior to induction of positive gravicurvature in horizontally-oriented roots by > 60%. The rate of curvature is not significantly different than the rate observed in control roots. Wrongway curvature which is observed in 30-40% of control roots is not observed in TPA-pretreated roots. Oscillatory movements observed in control roots after completion of gravitropic reorientation is completely dampened in TPA-pretreated roots. Pretreatment of roots with mTPA(3hr,1{mu}M), the inactive analog of TPA, does not significantly alter the kinetics of gravicurvature of primary roots of maize. Staurosporine (10{sup {minus}8}M), a microbial alkaloid which has been reported to have antifungal activity and to inhibit phospholipid/Ca{sup ++} dependent protein kinase, completely inhibits TPA-induced alteration of the kinetics of gravitropism. DAG (1-oleoyl-2-acetyl-rac-glycerol), a synthetic diglyceride activator of protein kinase C, exhibits similar activity to TPA. TPA-induced alterations in tissue response to auxin are presented.

  3. Initiation and elongation of lateral roots in Lactuca sativa

    Science.gov (United States)

    Zhang, N.; Hasenstein, K. H.

    1999-01-01

    Lactuca sativa cv. Baijianye seedlings do not normally produce lateral roots, but removal of the root tip or application of auxin, especially indole-butyric acid, triggered the formation of lateral roots. Primordia initiated within 9 h and were fully developed after 24 h by activating the pericycle cells opposite the xylem pole. The pericycle cells divided asymmetrically into short and long cells. The short cells divided further to form primordia. The effect of root tip removal and auxin application was reversed by 6-benzylaminopurine at concentrations >10(-8) M. The cytokinin oxidase inhibitor N1-(2chloro4pyridyl)-N2-phenylurea also suppressed auxin-induced lateral rooting. The elongation of primary roots was promoted by L-alpha-(2-aminoethoxyvinyl) glycine and silver ions, but only the latter enhanced elongation of lateral roots. The data indicate that the induction of lateral roots is controlled by basipetally moving cytokinin and acropetally moving auxin. Lateral roots appear to not produce ethylene.

  4. Processes for pretreating lignocellulosic biomass: A review

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J.D.

    1992-11-01

    This paper reviews existing and proposed pretreatment processes for biomass. The focus is on the mechanisms by which the various pretreatments act and the influence of biomass structure and composition on the efficacy of particular pretreatment techniques. This analysis is used to identify pretreatment technologies and issues that warrant further research.

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

    Directory of Open Access Journals (Sweden)

    Joanna Makowczyńska

    2011-01-01

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

  6. Adhesion mechanism of a gecko-inspired oblique structure with an adhesive tip for asymmetric detachment

    International Nuclear Information System (INIS)

    Sekiguchi, Yu; Sato, Chiaki; Takahashi, Kunio

    2015-01-01

    An adhesion model of an oblique structure with an adhesive tip is proposed by considering a limiting stress for adhesion to describe the detachment mechanism of gecko foot hairs. When a force is applied to the root of the oblique structure, normal and shear stresses are generated at contact and the adhesive tip is detached from the surface when reaching the limiting stress. An adhesion criterion that considers both the normal and shear stresses is introduced, and the asymmetric detachment of the oblique structure is theoretically investigated. In addition, oblique beam array structures are manufactured, and an inclination effect of the structure on the asymmetric detachment is experimentally verified. (paper)

  7. Measuring Fan-Blade-Tip Displacements

    Science.gov (United States)

    Berry, Robert F., Jr.

    1988-01-01

    Magnets and Hall-effect transducers used to monitor tip-to-shroud clearances. Mounting permanent magnet in end of fan blade and monitoring tip-to-shroud distance by use of output of Hall-effect transducers affixed to surface of shroud. Transducers provide real-time information. By placing magnets in each fan-blade tip, complete set monitored sequentially as each blade rotates past sensor. Application in many rotating machines, providing surrounding materials nonmagnetic and temperatures not severe.

  8. Sugars en route to the roots. Transport, metabolism and storage within plant roots and towards microorganisms of the rhizosphere.

    Science.gov (United States)

    Hennion, Nils; Durand, Mickael; Vriet, Cécile; Doidy, Joan; Maurousset, Laurence; Lemoine, Rémi; Pourtau, Nathalie

    2018-04-28

    In plants, root is a typical sink organ that relies exclusively on the import of sugar from the aerial parts. Sucrose is delivered by the phloem to the most distant root tips and, en route to the tip, is used by the different root tissues for metabolism and storage. Besides, a certain portion of this carbon is exuded in the rhizosphere, supplied to beneficial microorganisms and diverted by parasitic microbes. The transport of sugars towards these numerous sinks either occurs symplastically through cell connections (plasmodesmata) or is apoplastically mediated through membrane transporters (MST, SUT/SUC and SWEET) that control monosaccharide and sucrose fluxes. Here, we review recent progresses on carbon partitioning within and outside roots, discussing membrane transporters involved in plant responses to biotic and abiotic factors. This article is protected by copyright. All rights reserved.

  9. Removal of artificial dental calculus by use of conventional and diamond ultrasound tips.

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Mourão Pinho

    2017-04-01

    Full Text Available Introduction: Periodontal disease is considered a public health problem and may lead to serious complications as the general health of patient. The main therapeutic procedure is scaling and root planing, which can be performed by a variety of techniques and instruments Objective:The aim of the present study was to evaluate the removal of calculus, produced artificially, by using a conventional ultrasonic tip and a diamond – CVD tip. Method: The calculus was produced with artificial sawdust and glue-based cyanoacrylate and distributed in twenty areas also standardized on two plates of acrylic resin (chemical activated, holding 10 samples per plate. Standards / samples were divided by lot into two simple groups, being A (treated with conventional tip and B (treated with CVD tip. Results:The treatment in Group A, promoted an average area of 20.48 ± 4.20 mm2 free of artificial calculus which is significantly higher (p <0.05 than the area removed in Group B (15.37 ± 5.29 mm2. Conclusion:The results showed that the conventional tip presented higher results than CVD tip for efficacy in the removal of calculus.

  10. Aluminium-induced reduction of plant growth in alfalfa (Medicago sativa) is mediated by interrupting auxin transport and accumulation in roots.

    Science.gov (United States)

    Wang, Shengyin; Ren, Xiaoyan; Huang, Bingru; Wang, Ge; Zhou, Peng; An, Yuan

    2016-07-20

    The objective of this study was to investigate Al(3+)-induced IAA transport, distribution, and the relation of these two processes to Al(3+)-inhibition of root growth in alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or 100 μM AlCl3 and were foliar sprayed with water or 6 mg L(-1) IAA. Aluminium stress resulted in disordered arrangement of cells, deformed cell shapes, altered cell structure, and a shorter length of the meristematic zone in root tips. Aluminium stress significantly decreased the IAA concentration in apical buds and root tips. The distribution of IAA fluorescence signals in root tips was disturbed, and the IAA transportation from shoot base to root tip was inhibited. The highest intensity of fluorescence signals was detected in the apical meristematic zone. Exogenous application of IAA markedly alleviated the Al(3+)-induced inhibition of root growth by increasing IAA accumulation and recovering the damaged cell structure in root tips. In addition, Al(3+) stress up-regulated expression of AUX1 and PIN2 genes. These results indicate that Al(3+)-induced reduction of root growth could be associated with the inhibitions of IAA synthesis in apical buds and IAA transportation in roots, as well as the imbalance of IAA distribution in root tips.

  11. Spiralizations and tropisms in Arabidopsis roots.

    Science.gov (United States)

    Migliaccio, F; Piconese, S

    2001-12-01

    When Arabidopsis seedlings are grown on a hard-agar plate, their primary roots show characteristic spiralling movements, apparent as waves, coils and torsions, together with a slanting toward the right-hand side. All these movements are believed to be the result of three different processes acting on the roots: circumnutation, positive gravitropism and negative thigmotropism. The basic movement of the roots is described as that of a growing right-handed helix, which, because of the root tip hitting the agar plate, is continuously switched from the right-hand to the left-hand of the growth direction, and vice versa. This movement also produces a slanting root-growth direction toward the right-hand because of the incomplete waves made by the right-handed root to the left-hand. By contrast, the torsions seen in the coils and waves are interpreted as artefacts that form as an adaptation of the three-dimensional root helix to the flat two-dimensional agar surface.

  12. The tip of the iceberg

    DEFF Research Database (Denmark)

    Bjørst, Lill Rastad

    2010-01-01

      Abstract: The tip of the iceberg: Ice as a nonhuman actor of the climate change debate   The global climate change debate has the Arctic as a core region of concern and ice has become a central aspect of discourses. This article discusses ice representations from six different contexts linked...... to the 2009 United Nations Climate Change Conference (COP15) in Copenhagen. The author argues that even though the discussions often seem to be centred on ice alone, the latter gets inscribed in narratives and metaphors which have wider implications for how the Arctic and its Indigenous peoples...... are represented. Ice becomes a nonhuman actor, framing the discussions, acting in specific ways, and linking hybrid networks. Indeed it is used in diverse platforms by scientists, politicians, governments, NGOs, as well as Inuit hunters and fishermen...

  13. Evaluation of apical root resorption in orthodontic patients with maxillary anterior intrusion using utility arches and mini screws: A comparative clinical trial

    Directory of Open Access Journals (Sweden)

    Muraleedhara Bhat

    2014-01-01

    Full Text Available Objectives: The purpose of this study was to compare the amount of apical root resorption in orthodontic patients undergoing maxillary anterior intrusion using utility arches and mini screws; and to compare the efficacy of mini screws and utility arches in reducing over bite. Materials and Methods: The study sample consisted of 20 patients, divided in two groups. Group A consisted of ten patients in whom titanium mini-screws were used Group B consisted of 10 patients in whom utility arches made of 0.017 × 0.25" TMA were used. Diagnostic records (study models and radiovisiography [RVG] were taken at 2 time intervals, T1 (just before implant/utility arch placement and T2 (at the end of intrusion 6 months later. The pre and post radiographic images were measured from incisal tip to the root apex with the help of intrascan DC software. Root resorption was computed as the difference between the pre-treatment total tooth length and the post treatment total tooth length. These values were subjected to statistical analyses using SPSS 16.00 statistical software. (Statistical Package for the Social Sciences, IBM Corporation, December 2007 Results: The results showed that root resorption was seen in both groups. Amount of resorption seen was higher in mini implant group than utility arch group. Mini implants were more efficient in reducing the overbite when compared to utility arches. Conclusion: It was concluded from the study that intrusion using mini implant resulted in more root resorption than utility arch; and mini implant was more effective in intruding the incisors than utility arch.

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

    DEFF Research Database (Denmark)

    Shin, K. W.; Andersen, Poul

    2015-01-01

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

  15. Tank Focus Area pretreatment activities

    International Nuclear Information System (INIS)

    McGinnis, C.P.; Welch, T.D.; Manke, K.L.

    1997-01-01

    Plans call for the high-level wastes to be retrieved from the tanks and immobilized in a stable waste form suitable for long-term isolation. Chemistry and chemical engineering operations are required to retrieve the wastes, to condition the wastes for subsequent steps, and to reduce the costs of the waste management enterprise. Pretreatment includes those processes between retrieval and immobilization, and includes preparation of suitable feed material for immobilization and separations to partition the waste into streams that yield lower life-cycle costs. Some of the technologies being developed by the Tank Focus Area (TFA) to process these wastes are described. These technologies fall roughly into three areas: (1) solid/liquid separation (SLS), (2) sludge pretreatment, and (3) supernate pretreatment

  16. Twelve Tips for Effective Electronic Presentation.

    Science.gov (United States)

    Crosby, Joy

    1994-01-01

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

  17. Economics of tipping the climate dominoes

    Science.gov (United States)

    Lemoine, Derek; Traeger, Christian P.

    2016-05-01

    Greenhouse gas emissions can trigger irreversible regime shifts in the climate system, known as tipping points. Multiple tipping points affect each other’s probability of occurrence, potentially causing a `domino effect’. We analyse climate policy in the presence of a potential domino effect. We incorporate three different tipping points occurring at unknown thresholds into an integrated climate-economy model. The optimal emission policy considers all possible thresholds and the resulting interactions between tipping points, economic activity, and policy responses into the indefinite future. We quantify the cost of delaying optimal emission controls in the presence of uncertain tipping points and also the benefit of detecting when individual tipping points have been triggered. We show that the presence of these tipping points nearly doubles today’s optimal carbon tax and reduces peak warming along the optimal path by approximately 1 °C. The presence of these tipping points increases the cost of delaying optimal policy until mid-century by nearly 150%.

  18. DGGE fragments oscillate with or counter to fluctuations in cultivable bacteria along wheat roots

    NARCIS (Netherlands)

    van Diepeningen, Anne D; de Vos, Oscar J; Zelenev, Vladimir V; Semenov, Alexandre M; van Bruggen, Ariena H C

    2005-01-01

    Previously, we showed that bacterial populations oscillate in response to a moving substrate source such as a root tip, resulting in moving wavelike distributions along roots. For this article, we investigated if bacterial communities fluctuate as a whole or if there is a succession in bacterial

  19. Nanobits - exchangable and customisable scanning probe tips

    DEFF Research Database (Denmark)

    Yildiz, Izzet

    Invention of atomic force microscopy (AFM) pioneered a novel aspect for the surface metrology concept. A range of scanning probe methods have been developed over the years based on different sorts of tip-surface interaction: electrical, optical, thermal, force. Reproducible and fast fabrication...... miniaturisation requires the scanning probes to adapt into finer geometries to provide higher lateral resolution. To meet these needs critical dimension AFM (CD-AFM) and deep trench AFM (DT-AFM) were invented, which use different types of AFM tips: high-aspect-ratio tips for DT-AFM and CD tips for CD...... replacement could greatly increase the efficiency and adaptability of a CD system. In this PhD study, NanoBits – nano-sized customisable and exchangeable scanning probe tips – were developed to meet the demands of current AFM applications. Two different methods were followed for the fabrication of Nano...

  20. Seedling root targets

    Science.gov (United States)

    Diane L. Haase

    2011-01-01

    Roots are critical to seedling performance after outplanting. Although root quality is not as quick and simple to measure as shoot quality, target root characteristics should be included in any seedling quality assessment program. This paper provides a brief review of root characteristics most commonly targeted for operational seedling production. These are: root mass...

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

    Science.gov (United States)

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

    2018-02-01

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

  2. Accumulation and translocation of K+, Na+ and Ca2+ supplied to the different root zones of corn seedlings

    International Nuclear Information System (INIS)

    Marschner, H.; Richter, Ch.

    1973-01-01

    In various distances from the tip of the primary root of 9 days old corn seedlings nutrient solution labelled with 42 K, 22 Na or 45 Ca was supplied to a 3 cm section of the root. The remainder of the root system was supplied with an identical nutrient solution but non-labelled. After 24 hours the roots were segmented and analysed for their content of 42 K, 22 Na or 45 Ca. From the treated zone K + was not only translocated in direction of the shoot but also to a high degree in direction of the root tip where a pronounced accumulation of K + was evident. In contrast to this most of the Na + , which was taken up, was accumulated in the treated zone, whereas the translocation in direction of the shoot was restricted; some translocation in direction of the root tip was detectable. The accumulation of Ca 2+ in the treated zone was less pronounced, most of the Ca 2+ was translocated to the shoot. There was no translocation of Ca 2+ in direction of the root tip (phloem transport). Supply of the same ion to the remainder of the root system scarcely affected uptake and translocation of this ion from the treated zone; however, in the presence of K + in the external solution pronounced exchange reactions and efflux of K + took place. When K + and Na + were simultaneously present in the treated zone the uptake of Na + was strongly depressed; uptake and translocation of Na + were stimulated however, when K + was supplied only to the remainder of the root system. When K + , Na + or Ca 2+ were supplied to different root zones in the region from 0-18 cm behind the root tip, in these fast growing roots the total uptake was the same in a range of 3-18 cm behind the tip. In the tip zone (0-3 cm) however, the uptake of K + was lower and the uptake of Ca 2+ was higher than in the other root zones. For all 3 cations with increasing distance from the root tip, the accumulation in the treated zone decreased and the translocation from this zone in direction of the shoot increased. The

  3. The Microtubule-Associated Protein MAP18 Affects ROP2 GTPase Activity during Root Hair Growth1[OPEN

    Science.gov (United States)

    Kang, Erfang; Zheng, Mingzhi; Zhang, Yan; Yuan, Ming; Fu, Ying

    2017-01-01

    Establishment and maintenance of the polar site are important for root hair tip growth. We previously reported that Arabidopsis (Arabidopsis thaliana) MICROTUBULE-ASSOCIATED PROTEIN18 (MAP18) functions in controlling the direction of pollen tube growth and root hair elongation. Additionally, the Rop GTPase ROP2 was reported as a positive regulator of both root hair initiation and tip growth in Arabidopsis. Both loss of function of ROP2 and knockdown of MAP18 lead to a decrease in root hair length, whereas overexpression of either MAP18 or ROP2 causes multiple tips or a branching hair phenotype. However, it is unclear whether MAP18 and ROP2 coordinately regulate root hair growth. In this study, we demonstrate that MAP18 and ROP2 interact genetically and functionally. MAP18 interacts physically with ROP2 in vitro and in vivo and preferentially binds to the inactive form of the ROP2 protein. MAP18 promotes ROP2 activity during root hair tip growth. Further investigation revealed that MAP18 competes with RhoGTPase GDP DISSOCIATION INHIBITOR1/SUPERCENTIPEDE1 for binding to ROP2, in turn affecting the localization of active ROP2 in the plasma membrane of the root hair tip. These results reveal a novel function of MAP18 in the regulation of ROP2 activation during root hair growth. PMID:28314794

  4. AtCSLD3, a cellulose synthase-like gene important for root hair growth in arabidopsis.

    Science.gov (United States)

    Wang, X; Cnops, G; Vanderhaeghen, R; De Block, S; Van Montagu, M; Van Lijsebettens, M

    2001-06-01

    A member of the cellulose synthase-like (subfamily D) gene family of Arabidopsis, AtCSLD3, has been identified by T-DNA tagging. The analysis of the corresponding mutant, csld3-1, showed that the AtCSLD3 gene plays a role in root hair growth in plants. Root hairs grow in phases: First a bulge is formed and then the root hair elongates by polarized growth, the so-called "tip growth." In the mutant, root hairs were initiated at the correct position and grew into a bulge, but their elongation was severely reduced. The tips of the csld3-1 root hairs easily leaked cytoplasm, indicating that the tensile strength of the cell wall had changed at the site of the tip. Based on the mutant phenotype and the functional conservation between CSLD3 and the genuine cellulose synthase proteins, we hypothesized that the CSLD3 protein is essential for the synthesis of polymers for the fast-growing primary cell wall at the root hair tip. The distinct mutant phenotype and the ubiquitous expression pattern indicate that the CSLD3 gene product is only limiting at the zone of the root hair tip, suggesting particular physical properties of the cell wall at this specific site of the root hair cell.

  5. Carbonic Acid Pretreatment of Biomass

    Energy Technology Data Exchange (ETDEWEB)

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic

  6. Profiling Gene Expression in Germinating Brassica Roots.

    Science.gov (United States)

    Park, Myoung Ryoul; Wang, Yi-Hong; Hasenstein, Karl H

    2014-01-01

    Based on previously developed solid-phase gene extraction (SPGE) we examined the mRNA profile in primary roots of Brassica rapa seedlings for highly expressed genes like ACT7 (actin7), TUB (tubulin1), UBQ (ubiquitin), and low expressed GLK (glucokinase) during the first day post-germination. The assessment was based on the mRNA load of the SPGE probe of about 2.1 ng. The number of copies of the investigated genes changed spatially along the length of primary roots. The expression level of all genes differed significantly at each sample position. Among the examined genes ACT7 expression was most even along the root. UBQ was highest at the tip and root-shoot junction (RS). TUB and GLK showed a basipetal gradient. The temporal expression of UBQ was highest in the MZ 9 h after primary root emergence and higher than at any other sample position. Expressions of GLK in EZ and RS increased gradually over time. SPGE extraction is the result of oligo-dT and oligo-dA hybridization and the results illustrate that SPGE can be used for gene expression profiling at high spatial and temporal resolution. SPGE needles can be used within two weeks when stored at 4 °C. Our data indicate that gene expression studies that are based on the entire root miss important differences in gene expression that SPGE is able to resolve for example growth adjustments during gravitropism.

  7. Root and Root Canal Morphology of Maxillary First Premolars: A Literature Review and Clinical Considerations.

    Science.gov (United States)

    Ahmad, Ibrahim Ali; Alenezi, Mohammad Ahmad

    2016-06-01

    Sound knowledge of the external and internal morphology of the different teeth groups is essential to ensure a successful outcome of root canal treatment. The aims of this study were to review the available literature with respect to the root and root canal morphology of maxillary first premolars and discuss the clinical considerations of this morphology on the various dental procedures. The MEDLINE/PubMed and Scopus databases were searched for relevant literature. The identified publications were classified into anatomic studies and clinical case reports. The data extracted from anatomic studies were tabulated, and weighted averages for certain internal and external morphologic features were calculated. The anatomic and developmental variations in the clinical case reports were summarized. A total of 92 studies (45 anatomic studies and 47 case reports) including a total of 11,299 teeth were identified. The majority of maxillary first premolars had 1 root (41.7%) or 2 roots (56.6%). Regardless of the number of roots, the vast majority (86.6%) had 2 root canals, with type IV (2-2) being the most common canal configuration (64.8%). The majority of the apical foramina (66.6%) did not coincide with the apical root tip. About 38% of the teeth had lateral canals, 12.3% had apical deltas, and 16.0% had isthmi. The clinical case reports showed that the 3-rooted variant was the most common anatomic variation, and developmental anomalies were rarely reported. The maxillary first premolars are predominantly 2-rooted teeth with 2 root canals. However, the clinician should be aware about the possible anatomic variations of these teeth and their relationship with the adjacent anatomic structures while planning and performing endodontic, restorative, periodontal, and surgical procedures. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Migraine strikes as neuronal excitability reaches a tipping point.

    Directory of Open Access Journals (Sweden)

    Marten Scheffer

    Full Text Available Self-propagating waves of cerebral neuronal firing, known as spreading depolarisations, are believed to be at the roots of migraine attacks. We propose that the start of spreading depolarisations corresponds to a critical transition that occurs when dynamic brain networks approach a tipping point. We show that this hypothesis is consistent with current pathogenetic insights and observed dynamics. Our view implies that migraine strikes when modulating factors further raise the neuronal excitability in genetically predisposed subjects to a level where even minor perturbations can trigger spreading depolarisations. A corollary is that recently discovered generic early warning indicators for critical transitions may be used to predict the onset of migraine attacks even before patients are clinically aware. This opens up new avenues for dissecting the mechanisms for the onset of migraine attacks and for identifying novel prophylactic treatment targets for the prevention of attacks.

  9. Crack Tip Mechanics in Distortion Gradient Plasticity

    DEFF Research Database (Denmark)

    Fuentes-Alonso, Sandra; Martínez Pañeda, Emilio

    2017-01-01

    The important role of geometrically necessary dislocations in structural integrity assessment has encouraged an extensive use of strain gradient plasticity theories to characterize the behavior at the small scales involved in crack tip deformation. However, despite the popularity of Distortion...... Gradient Plasticity (DGP), the influence on crack tip mechanics of DGP's distinguishing features that entail superior modelling capabilities has not been investigated yet. In this work crack tip fields are thoroughly examined by implementing the higher order theory of DGP in an implicit finite element...

  10. [Tip and torque changes in maxillary buccal segment after orthodontic treatment: a three-dimensional study].

    Science.gov (United States)

    Chen, Gui; Qin, Yi-fei; Xu, Tian-min

    2010-11-01

    To investigate three-dimensional imaging registration and superimposition techniques in measuring the tip and torque change of upper canine, premolar and first molar after orthodontic treatment. Twenty-eight subjects (14 extraction cases and 14 non-extraction cases) with full records were randomly selected from the Department of Orthodontics, Peking University School and Hospital of Stomatology. The pre-and post-treatment upper dental casts were digitized with three-dimensional spot laser scanner and superimposed with reverse engineering software. The facial axis of the clinical crown (FACC) was transferred from post-treatment teeth to the pre-treatment teeth using three-dimensional imaging registration. The occlusal plane was constructed on the post-treatment upper digital cast and the tip and torque values were measured. In the non-extraction group, the tip of the second premolar decreased by 1.5° (P orthodontic treatment tended to tip the upper second premolar distally and increased the buccal crown torque of the upper premolars while extraction treatment increased the lingual crown torque of the upper canine.

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

    Science.gov (United States)

    Shin, K. W.; Andersen, P.

    2015-12-01

    The blade tip loading is often reduced as an effort to restrain sheet and tip vortex cavitation in the design of marine propellers. This CFD analysis demonstrates that an excessive reduction of the tip loading can cause cloud cavitation responsible for much of noise and surface erosion. Detached eddy simulations (DES) are made for cavitating flows on three tip- modified propellers, of which one is a reference propeller having an experimental result from a cavitation tunnel test with a hull model, and the other two are modified from the reference propeller by altering the blade tip loading. DES results have been validated against the experiment in terms of sheet and cloud cavitation. In DES, non-uniform hull wake is modelled by using the inlet flow and momentum sources instead of including a hull model. A 4-bladed Kappel propeller with a smooth tip bending towards the suction side is used as the reference propeller. For the reference propeller, sheet cavitation extends over a whole chord length in the hull wake peak. As the blade gets out of the wake peak, the rear part of sheet cavity is detached in a form of cloud cavitation. For the reference propeller, the tip pitch reduction from the maximum is about 35%. When decreasing the tip pitch reduction to 10%, tip vortex cavitation is formed and cloud cavitation is significantly weakened. When increasing the tip pitch reduction to 60%, sheet cavitation slightly moves to inner radii and cloud cavitation grows larger.

  12. Graviresponsiveness of surgically altered primary roots of Zea mays

    Science.gov (United States)

    Maimon, E.; Moore, R.

    1991-01-01

    We examined the gravitropic responses of surgically altered primary roots of Zea mays to determine the route by which gravitropic inhibitors move from the root tip to the elongating zone. Horizontally oriented roots, from which a 1-mm-wide girdle of epidermis plus 2-10 layers of cortex were removed from the apex of the elongating zone, curve downward. However, curvature occurred only apical to the girdle. Filling the girdle with mucilage-like material transmits curvature beyond the girdle. Vertically oriented roots with a half-girdle' (i.e. the epidermis and 2-10 layers of the cortex removed from half of the circumference of the apex of the elongating zone) curve away from the girdle. Inserting the half-girdle at the base of the elongating zone induces curvature towards the girdle. Filling the half-circumference girdles with mucilage-like material reduced curvature significantly. Stripping the epidermis and outer 2-5 layers of cortex from the terminal 1.5 cm of one side of a primary root induces curvature towards the cut, irrespective of the root's orientation to gravity. This effect is not due to desiccation since treated roots submerged in water also curved towards their cut surface. Coating a root's cut surface with a mucilage-like substance minimizes curvature. These results suggest that the outer cell-layers of the root, especially the epidermis, play an important role in root gravicurvature, and the gravitropic signals emanating from the root tip can move apoplastically through mucilage.

  13. Calculated shape dependence of electromagnetic field in tip-enhanced Raman scattering by using a monopole antenna model

    Science.gov (United States)

    Kitahama, Yasutaka; Itoh, Tamitake; Suzuki, Toshiaki

    2018-05-01

    To evaluate the shape of an Ag tip with regard to tip-enhanced Raman scattering (TERS) signal, the enhanced electromagnetic (EM) field and scattering spectrum, arising from surface plasmon resonance at the apex of the tip, were calculated using a finite-difference time domain (FDTD) method. In the calculated forward scattering spectra from the smooth Ag tip, the band appeared within the visible region, similar to the experimental results and calculation for a corrugated Ag cone. In the FDTD calculation of TERS, the Ag tip acting as a monopole antenna was adopted by insertion of a perfect electric conductor between the root of the tip and a top boundary surface of the calculation space. As a result, the EM field was only enhanced at the apex. The shape dependence i.e. the EM field calculated at the apex with various curvatures on the different tapered tips, obtained using the monopole antenna model, was different from that simulated using a conventional dipole antenna model.

  14. Calculated shape dependence of electromagnetic field in tip-enhanced Raman scattering by using a monopole antenna model.

    Science.gov (United States)

    Kitahama, Yasutaka; Itoh, Tamitake; Suzuki, Toshiaki

    2018-01-05

    To evaluate the shape of an Ag tip with regard to tip-enhanced Raman scattering (TERS) signal, the enhanced electromagnetic (EM) field and scattering spectrum, arising from surface plasmon resonance at the apex of the tip, were calculated using a finite-difference time domain (FDTD) method. In the calculated forward scattering spectra from the smooth Ag tip, the band appeared within the visible region, similar to the experimental results and calculation for a corrugated Ag cone. In the FDTD calculation of TERS, the Ag tip acting as a monopole antenna was adopted by insertion of a perfect electric conductor between the root of the tip and a top boundary surface of the calculation space. As a result, the EM field was only enhanced at the apex. The shape dependence i.e. the EM field calculated at the apex with various curvatures on the different tapered tips, obtained using the monopole antenna model, was different from that simulated using a conventional dipole antenna model. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Tips for splinting traumatised teeth

    LENUS (Irish Health Repository)

    Leith, Rona

    2017-11-01

    A splint is required when teeth are mobile or need to be repositioned following a traumatic injury. The aim of splinting is to stabilise the injured tooth and maintain its position throughout the splinting period, improve function and provide comfort. Current best practice guidelines from the International Association for Dental Traumatology (IADT) recommend splinting for luxated, avulsed, root fractured and traumatically loosened permanent teeth.1,2 Splinting of primary teeth is usually not feasible. In general, the prognosis of a traumatised tooth is determined by the type of injury rather than the type of splint.3 However, correct splinting is important to maximise healing of the soft and hard tissues, and prevent further injury.1

  16. Tips for splinting traumatised teeth

    LENUS (Irish Health Repository)

    Leith, Rona

    2017-10-01

    A splint is required when teeth are mobile or need to be repositioned following a traumatic injury. The aim of splinting is to stabilise the injured tooth and maintain its position throughout the splinting period, improve function and provide comfort. Current best practice guidelines from the International Association for Dental Traumatology (IADT) recommend splinting for luxated, avulsed, root fractured and traumatically loosened permanent teeth.1,2 Splinting of primary teeth is usually not feasible. In general, the prognosis of a traumatised tooth is determined by the type of injury rather than the type of splint.3 However, correct splinting is important to maximise healing of the soft and hard tissues, and prevent further injury.1-6

  17. Smooth School Transitions: Tips for Military Families

    Science.gov (United States)

    ... Life Listen Text Size Email Print Share Smooth School Transitions: Tips for Military Families Page Content Article ... Internet is a great resource for this. District & School Web sites Parents and children can visit the ...

  18. Helping Your Child: Tips for Parents

    Science.gov (United States)

    ... inactive computer and video games, or listening to music on hand-held devices while sitting down. Tips ... habits or weight. Remember, you play the biggest role in your children's lives. You can help your ...

  19. Tips for Teens with Diabetes: About Diabetes

    Science.gov (United States)

    National Diabetes Education Program (NDEP), 2010

    2010-01-01

    Diabetes is a serious disease. It means that one's blood glucose, also called blood sugar, is too high. Having too much glucose in a person's blood is not healthy. This paper offers tips for managing diabetes.

  20. Winter Safety Tips for Older Adults

    Science.gov (United States)

    Winter Safety Tips for Older Adults Expert Information from Healthcare Professionals Who Specialize in the Care of ... thick clothing. Think about getting your thermals! –Essential winter wears: hats, gloves or preferably mittens, winter coat, ...

  1. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are at increased risk for overexposure ... associated with sun exposure. "It's easy to associate winter with frostbite and windburn, but most people are ...

  2. Can't sleep? Try these tips

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000853.htm Can't sleep? Try these tips To use the sharing features ... time. But if it happens often, lack of sleep can affect your health and make it hard ...

  3. Sleep Tips: 7 Steps to Better Sleep

    Science.gov (United States)

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

  4. Impetigo: Tips for Treatment and Prevention

    Science.gov (United States)

    ... DO Videos Contact Close ‹ Back to Healthy Living Impetigo: Tips for Treatment and Prevention The symptoms of ... to other parts of their bodies. Causes of Impetigo Impetigo usually affects preschool and school-aged children, ...

  5. Next Stop Adulthood: Tips for Parents

    Science.gov (United States)

    ... Email Print Share Next Stop Adulthood: Tips For Parents Page Content Article Body Becoming a young adult is exciting, difficult, and scary for both parents and teens. It is a time of increasing ...

  6. 6 Tips: IBS and Complementary Health Practices

    Science.gov (United States)

    ... health practice for IBS, here are 6 tips: Hypnotherapy (hypnosis). This practice involves the power of suggestion by ... IBS. According to reviews of the scientific literature, hypnotherapy may be a helpful treatment for managing IBS ...

  7. Tips to Manage Anxiety and Stress

    Science.gov (United States)

    ... 2018 Conference Snapshot Tips to Manage Anxiety and Stress When you're feeling anxious or stressed, the ... Subscribe to ADAA Triumph: Free Monthly E-News Stress Relief Kits Feeling stressed? Get an ADAA stress ...

  8. Tip velocity tracking control for elastic manipulators

    Science.gov (United States)

    Sever, Manfred Dieter Martin

    A unique approach to tip velocity control of an elastic robotic manipulator is presented. This method has potential application in teleoperation control and in applications where the trajectory is generated in real-time. Control is effected by reducing the tip velocity tracking error between the desired tip velocity and the measured tip velocity. Thus, in teleoperation, the concept of dead reckoning is used, so that while the manipulator's desired tip velocity is specified, the goal is for the tip to follow a path, leading toward a desired terminal position. This is done by concentrating the controller's effort on the manipulator tip while allowing the manipulator's links to deform., The controller utilizes a gain scheduling scheme to arrive at an appropriate feedback law. The control algorithm is implemented using a parallel-processing scheme on a multiprocessor system which consists of INMOS TransputersRTM . Experimental results are obtained using Radius, the Space Robotics Laboratory Facility at the University of Toronto Institute for Aerospace Studies. Radius was designed to serve specifically as a test-bed for the development and evaluation of control methods for elastic manipulators. For the present work Radius is configured as a two-link manipulator with both links structurally flexible. One of the trajectories used for the simulations and experiment is a square, which is quite difficult for an elastic manipulator to execute. This box trajectory is more demanding than trajectories typically executed by Canadarm and so link elasticity becomes an important consideration. The effect of elasticity is demonstrated using an independent joint PD controller. In simulation, excellent tip velocity tracking was achieved using the proposed controller. In the experiment, reasonable accuracy in following the desired tip path was attained, however, disturbances, mainly a result of unmodeled joint dynamics, caused degraded performance. The controller may be improved by

  9. Roles of amyloplasts and water deficit in root tropisms.

    Science.gov (United States)

    Ponce, Georgina; Rasgado, Fátima A; Cassab, Gladys I

    2008-02-01

    Directed growth of roots in relation to a moisture gradient is called hydrotropism. The no hydrotropic response (nhr1) mutant of Arabidopsis lacks a hydrotropic response, and shows a stronger gravitropic response than that of wild type (wt) in a medium with an osmotic gradient. Local application of abscisic acid (ABA) to seeds or root tips of nhr1 increased root downward growth, indicating the critical role of ABA in tropisms. Wt roots germinated and treated with ABA in this system were strongly gravitropic, even though they had almost no starch amyloplasts in the root-cap columella cells. Hydrotropically stimulated nhr1 roots, with or without ABA, maintained starch in the amyloplasts, as opposed to those of wt. Hence, the near-absence (wt) or abundant presence (nhr1) of starch granules does not influence the extent of downward gravitropism of the roots in an osmotic gradient medium. Starch degradation in the wt might help the root sustain osmotic stress and carry out hydrotropism, instead of reducing gravity responsiveness. nhr1 roots might be hydrotropically inactive because they maintain this starch reserve in the columella cells, sustaining both their turgor and growth, and in effect minimizing the need for hydrotropism and at least partially disabling its mechanism. We conclude that ABA and water stress are critical regulators of root tropic responses.

  10. The impact of an erbium, chromium:yttrium-scandium-gallium-garnet laser with radial-firing tips on endodontic treatment.

    Science.gov (United States)

    Schoop, U; Barylyak, A; Goharkhay, K; Beer, F; Wernisch, J; Georgopoulos, A; Sperr, W; Moritz, A

    2009-01-01

    Radial-firing tips should allow a more homogeneous laser irradiation of root canal walls. The aim of the study was to assess the effects of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation in conjunction with those newly designed tips. The investigation comprised bacteriology, morphological evaluations and temperature measurements. Root canals were inoculated with two test strains and laser irradiated with power settings of 0.6 W and 0.9 W and a repetition rate of 20 Hz. Subsequently, the samples were subjected to microbiological evaluation. The morphological changes of the canal walls were assessed by scanning electron microscopy. To reveal possible thermal side effects, we carried out temperature measurements. The bacteriological evaluation revealed a decisive disinfectant effect. Scanning electron microscopy showed the homogeneous removal of smear layer from the root canal walls. The temperature rise at the root surface during the irradiation was moderate, yielding 1.3 degrees C for the 0.6 W setting and 1.6 degrees C for the 0.9 W setting. The investigations indicated that the Er,Cr:YSGG laser, in conjunction with radial-firing tips, is a suitable tool for the elimination of bacteria in root canals and for the removal of smear layer.

  11. Tipping the balance: robustness of tip cell selection, migration and fusion in angiogenesis.

    Directory of Open Access Journals (Sweden)

    Katie Bentley

    2009-10-01

    Full Text Available Vascular abnormalities contribute to many diseases such as cancer and diabetic retinopathy. In angiogenesis new blood vessels, headed by a migrating tip cell, sprout from pre-existing vessels in response to signals, e.g., vascular endothelial growth factor (VEGF. Tip cells meet and fuse (anastomosis to form blood-flow supporting loops. Tip cell selection is achieved by Dll4-Notch mediated lateral inhibition resulting, under normal conditions, in an interleaved arrangement of tip and non-migrating stalk cells. Previously, we showed that the increased VEGF levels found in many diseases can cause the delayed negative feedback of lateral inhibition to produce abnormal oscillations of tip/stalk cell fates. Here we describe the development and implementation of a novel physics-based hierarchical agent model, tightly coupled to in vivo data, to explore the system dynamics as perpetual lateral inhibition combines with tip cell migration and fusion. We explore the tipping point between normal and abnormal sprouting as VEGF increases. A novel filopodia-adhesion driven migration mechanism is presented and validated against in vivo data. Due to the unique feature of ongoing lateral inhibition, 'stabilised' tip/stalk cell patterns show sensitivity to the formation of new cell-cell junctions during fusion: we predict cell fates can reverse. The fusing tip cells become inhibited and neighbouring stalk cells flip fate, recursively providing new tip cells. Junction size emerges as a key factor in establishing a stable tip/stalk pattern. Cell-cell junctions elongate as tip cells migrate, which is shown to provide positive feedback to lateral inhibition, causing it to be more susceptible to pathological oscillations. Importantly, down-regulation of the migratory pathway alone is shown to be sufficient to rescue the sprouting system from oscillation and restore stability. Thus we suggest the use of migration inhibitors as therapeutic agents for vascular

  12. Disruption of actin filaments induces mitochondrial Ca2+ release to the cytoplasm and [Ca2+]c changes in Arabidopsis root hairs

    Directory of Open Access Journals (Sweden)

    Baluška František

    2010-03-01

    Full Text Available Abstract Background Mitochondria are dynamic organelles that move along actin filaments, and serve as calcium stores in plant cells. The positioning and dynamics of mitochondria depend on membrane-cytoskeleton interactions, but it is not clear whether microfilament cytoskeleton has a direct effect on mitochondrial function and Ca2+ storage. Therefore, we designed a series of experiments to clarify the effects of actin filaments on mitochondrial Ca2+ storage, cytoplasmic Ca2+ concentration ([Ca2+]c, and the interaction between mitochondrial Ca2+ and cytoplasmic Ca2+ in Arabidopsis root hairs. Results In this study, we found that treatments with latrunculin B (Lat-B and jasplakinolide (Jas, which depolymerize and polymerize actin filaments respectively, decreased membrane potential and Ca2+ stores in the mitochondria of Arabidopsis root hairs. Simultaneously, these treatments induced an instantaneous increase of cytoplasmic Ca2+, followed by a continuous decrease. All of these effects were inhibited by pretreatment with cyclosporin A (Cs A, a representative blocker of the mitochondrial permeability transition pore (mPTP. Moreover, we found there was a Ca2+ concentration gradient in mitochondria from the tip to the base of the root hair, and this gradient could be disrupted by actin-acting drugs. Conclusions Based on these results, we concluded that the disruption of actin filaments caused by Lat-B or Jas promoted irreversible opening of the mPTP, resulting in mitochondrial Ca2+ release into the cytoplasm, and consequent changes in [Ca2+]c. We suggest that normal polymerization and depolymerization of actin filaments are essential for mitochondrial Ca2+ storage in root hairs.

  13. Full tip imaging in atom probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Du, Sichao [School of Physics, The University of Sydney, NSW 2006 (Australia); Burgess, Timothy [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Tjing Loi, Shyeh [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Gault, Baptiste [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); Department of Materials Science and Engineering, McMaster University, 1280 Main St W, Hamilton, ON, Canada L8S 4L8 (Canada); Gao, Qiang [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Bao, Peite; Li, Li [School of Physics, The University of Sydney, NSW 2006 (Australia); Cui, Xiangyuan; Kong Yeoh, Wai [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Hoe Tan, Hark; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); Zheng, Rongkun, E-mail: rongkun.zheng@sydney.edu.au [School of Physics, The University of Sydney, NSW 2006 (Australia)

    2013-01-15

    Atom probe tomography (APT) is capable of simultaneously revealing the chemical identities and three dimensional positions of individual atoms within a needle-shaped specimen, but suffers from a limited field-of-view (FOV), i.e., only the core of the specimen is effectively detected. Therefore, the capacity to analyze the full tip is crucial and much desired in cases that the shell of the specimen is also the region of interest. In this paper, we demonstrate that, in the analysis of III-V nanowires epitaxially grown from a substrate, the presence of the flat substrate positioned only micrometers away from the analyzed tip apex alters the field distribution and ion trajectories, which provides extra image compression that allows for the analysis of the entire specimen. An array of experimental results, including field desorption maps, elemental distributions, and crystallographic features clearly demonstrate the fact that the whole tip has been imaged, which is confirmed by electrostatic simulations. -- Highlights: Black-Right-Pointing-Pointer The full tip has been imaged by atom probe tomography. Black-Right-Pointing-Pointer The conductive substrate close to specimen tip introduces extra image compression. Black-Right-Pointing-Pointer The apex of the tip is far from a hemispherical shape. Black-Right-Pointing-Pointer This work demonstrates a way to increase the FOV of APT.

  14. Expression of tomato SlTIP2;2 enhances the tolerance to salt stress in the transgenic Arabidopsis and interacts with target proteins.

    Science.gov (United States)

    Xin, Shichao; Yu, Guohong; Sun, Linlin; Qiang, Xiaojing; Xu, Na; Cheng, Xianguo

    2014-11-01

    Three independent transgenic Arabidopsis lines expressing SlTIP2;2 from Solanum lycopersicum L. cv. Lichun under the control of its endogenous promoter were used to analyze the expression of SlTIP2;2 and the salt stress tolerance under NaCl concentration gradient treatment. The expression patterns of SlTIP2;2 were shown to be tissue-specific and NaCl dose-dependent under salt stress. SlTIP2;2-transformed Arabidopsis plants exhibited enhanced salt stress tolerance, and the physiological parameters suggested that SlTIP2;2 has close links with the ion homeostasis and antioxidant enzymes activities in salt-stressed transgenic Arabidopsis. Moreover, SlTIP2;2 expression significantly affected the Na(+) and K(+) fluxes from the root meristematic zones and resulted in remarkable changes in the morphology of the pith ray cells in the inflorescence stems of transgenic Arabidopsis. Based on the yeast growth assay, β-galactosidase activity testing and bimolecular fluorescence complementation, SlTIP1;1, SlTIP2;1 and an UDP-galactose transporter were confirmed to interact with SlTIP2;2, which may greatly broaden our understanding of the physiological functions of aquaporins.

  15. computer-aided root aided root aided root aided root-locus

    African Journals Online (AJOL)

    User

    equation are the same as the poles of the close loop system. Ideally, a desired performance can be achieved a control system by adjusting the location of roots in the s-plane by varying one or mo system parameters. Root-locus Method is a line. 8023278605. AIDED ROOT. AIDED ROOT-LOCUS NUMERICAL TECHNIQUE.

  16. ROOT Reference Documentation

    CERN Document Server

    Fuakye, Eric Gyabeng

    2017-01-01

    A ROOT Reference Documentation has been implemented to generate all the lists of libraries needed for each ROOT class. Doxygen has no option to generate or add the lists of libraries for each ROOT class. Therefore shell scripting and a basic C++ program was employed to import the lists of libraries needed by each ROOT class.

  17. Pretreatment Solution for Water Recovery Systems

    Science.gov (United States)

    Muirhead, Dean (Inventor)

    2018-01-01

    Chemical pretreatments are used to produce usable water by treating a water source with a chemical pretreatment that contains a hexavalent chromium and an acid to generate a treated water source, wherein the concentration of sulfate compounds in the acid is negligible, and wherein the treated water source remains substantially free of precipitates after the addition of the chemical pretreatment. Other methods include reducing the pH in urine to be distilled for potable water extraction by pretreating the urine before distillation with a pretreatment solution comprising one or more acid sources selected from a group consisting of phosphoric acid, hydrochloric acid, and nitric acid, wherein the urine remains substantially precipitate free after the addition of the pretreatment solution. Another method described comprises a process for reducing precipitation in urine to be processed for water extraction by mixing the urine with a pretreatment solution comprising hexavalent chromium compound and phosphoric acid.

  18. Salt stress affects the redox status of Arabidopsis root meristems

    Directory of Open Access Journals (Sweden)

    Keni eJiang

    2016-02-01

    Full Text Available We report the redox status (profiles for specific populations of cells that comprise the Arabidopsis root tip. For recently germinated, 3-5-day-old seedlings we show that the region of the root tip with the most reduced redox status includes the root cap initials, the quiescent center and the most distal portion of the proximal meristem, and coincides with (overlays the region of the auxin maximum. As one moves basally, further into the proximal meristem, and depending on the growth conditions, the redox status becomes more oxidized, with a 5-10 mV difference in redox potential between the two borders delimiting the proximal meristem. At the point on the root axis at which cells of the proximal meristem cease division and enter the transition zone, the redox potential levels off and remains more or less unchanged throughout the transition zone. As cells leave the transition zone and enter the zone of elongation the redox potentials become more oxidized. Treating roots with salt (50, 100 and 150 mM NaCl results in marked changes in root meristem structure and development, and is preceded by changes in the redox profile, which flattens, and initially becomes more oxidized, with pronounced changes in the redox potentials of the root cap, the root cap initials and the quiescent center. Roots exposed to relatively mild levels of salt (< 100 mM are able to re-establish a normal, pre-salt treatment redox profile 3-6 days after exposure to salt. Coincident with the salt-associated changes in redox profiles are changes in the distribution of auxin transporters (AUX1, PIN1/2, which become more diffuse in their localization. We conclude that salt stress affects root meristem maintenance, in part, through changes in redox and auxin transport.

  19. OsPIN2, which encodes a member of the auxin efflux carrier proteins, is involved in root elongation growth and lateral root formation patterns via the regulation of auxin distribution in rice.

    Science.gov (United States)

    Inahashi, Hiroki; Shelley, Israt Jahan; Yamauchi, Takaki; Nishiuchi, Shunsaku; Takahashi-Nosaka, Misuzu; Matsunami, Maya; Ogawa, Atsushi; Noda, Yusaku; Inukai, Yoshiaki

    2018-02-15

    Auxin flow is important for different root developmental processes such as root formation, emergence, elongation and gravitropism. However, the detailed information about the mechanisms regulating the auxin flow is less well understood in rice. We characterized the auxin transport-related mutants, Ospin-formed2-1 (Ospin2-1) and Ospin2-2, which exhibited curly root phenotypes and altered lateral root-formation patterns in rice. The OsPIN2 gene encodes a member of the auxin-efflux carrier proteins that possibly regulates the basipetal auxin flow from the root tip towards the root-elongation zone. According to DR5-driven GUS expression, there is an asymmetric auxin distribution in the mutants that corresponded with the asymmetric cell elongation pattern in the mutant root tip. Auxin transport inhibitor, N-1-naphthylphthalamic acid (NPA), and Ospin2-1 Osiaa13 double mutant rescued the curly root phenotype indicating that this phenotype results from a defect in proper auxin distribution. The typical curly root phenotype was not observed when Ospin2-1 was grown in distilled water as an alternative to tap water, although higher auxin levels were found at the root tip region of the mutant than that of the wild type. Therefore, the lateral root formation zone in the mutant was shifted basipetally compared with the wild type. These results reflect that an altered auxin flow in the root tip region is responsible for root elongation growth and lateral root formation patterns in rice. This article is protected by copyright. All rights reserved.

  20. Characterization of root agravitropism induced by genetic, chemical, and developmental constraints

    International Nuclear Information System (INIS)

    Moore, R.; Fondren, W.M.; Marcum, H.

    1987-01-01

    The patterns and rates of organelle redistribution in columella (i.e., putative statocyte) cells of agravitropic agt mutants of Zea mays are not significantly different from those of columella cells in graviresponsive roots. Graviresponsive roots of Z. mays are characterized by a strongly polar movement of 45 Ca 2+ across the root tip from the upper to the lower side. Horizontally-oriented roots of agt mutants exhibit only a minimal polar transport of 45 Ca 2+ . Exogenously-induced asymmetries of Ca result in curvature of agt roots toward the Ca source. A similar curvature can be induced by a Ca asymmetry in normally nongraviresponsive (i.e., lateral) roots of Phaseolus vulgaris. Similarly, root curvature can be induced by placing the roots perpendicular to an electric field. This electrotropism increase with (1) currents between 8-35 mA, and (2) time between 1-9 hr when the current is constant. Electrotropism is reduced significantly by treating roots with triiodobenzoic acid (TIBA), an inhibitor of auxin transport. These results suggest that (1) if graviperception occurs via the sedimentation of amyloplasts in columella cells, then nongraviresponsive roots apparently sense gravity as do graviresponsive roots, (2) exogenously induced asymmetries of a gravitropic effector (i.e., Ca) can induce curvature of normally nongraviresponsive roots, (3) the gravity-induced downward movement of exogenously-applied 45 Ca 2+ across tips of graviresponsive roots does not occur in nongraviresponsive roots, (4) placing roots in an electrical field (i.e., one favoring the movement of ions such as Ca 2+ ) induces root curvature and (5) electrically-induced curvature is apparently dependent on auxin transport. These result are discussed relative to a model to account for the lack of graviresponsiveness by these roots

  1. Conversão in vitro de raízes e folhas de Miltonia flavescens Lindl. em protocormos e regeneração de plantas In vitro conversion of Miltonia flavescens Lindl. roots and leaf tip cells in protocorm like bodies and plant regeneration

    Directory of Open Access Journals (Sweden)

    Suzana Stefanello

    2009-02-01

    Full Text Available Objetivou-se, no presente trabalho, avaliar o efeito do 2,4-D e do BAP na formação de protocormos a partir de regiões meristemáticas da raiz e segmentos foliares de Miltonia flavescens Lindl., bem como testar o efeito de concentrações de sacarose e níveis de pH no crescimento in vitro dos protocormos. Ápices radiculares e segmentos de folhas de plantas germinadas in vitro foram inoculados em meio de cultura MS/2 suplementado com 2,4-D e BAP onde permaneceram por 210 dias no escuro, sendo transferidos para a luz e inoculados em meio de cultura isento de reguladores, avaliando-se a porcentagem de explantes com protocormos e o número médio de protocormos regenerados por explante. A associação de 3 mg L-1 de 2,4-D e 1 ou 3 mg L-1 de BAP proporcionou os melhores resultados quanto à formação de protocormos. Esses foram cultivados em meio de cultura MS/2 onde testou-se o efeito da sacarose (0, 15, 30, 45 e 60 g L-1 e do pH (5.0, 5.8 e 6.6 sobre o seu crescimento. As concentrações de 15 e 30 g L-1 de sacarose independentes do pH, mostraram-se mais eficientes para o cultivo in vitro da espécie proporcionando a formação de um maior número e comprimento de raízes, altura de parte aérea e peso da matéria fresca. O pH só apresentou-se significativo quando em combinação com 15 g L-1 de sacarose para as variáveis comprimento da maior raiz e peso da matéria fresca.The aim of the present work was to evaluate the effect of 2,4-D and BAP on the protocorm formation from meristematic areas of the root and leaf segments of Miltonia flavescens Lindl., as well as to test the effect of sucrose concentrations and pH levels on the in vitro growth of protocorms. Root apexes and leaf segments of in vitro-germinated plants were cultured on MS/2 culture medium supplemented with 2,4-D and BAP and kept in the dark for 210 days. Explants were then transferred to light and cultured on culture medium lacking growth regulators. Percentage of explants

  2. Comparative assessment of the polypeptide profiles from lateral and primary roots of Phaseolus vulgaris L

    Science.gov (United States)

    Westberg, J.; Odom, W. R.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    In Phaseolus vulgaris, primary roots show gravitational sensitivity soon after emerging from the seed. In contrast, lateral roots are agravitropic during early development, and become gravitropic after several cm growth. Primary and lateral root tissues were examined by polyacrylamide gel electrophoresis, coupled with western blotting techniques, to compare proteins which may contribute to the acquisition of gravitational sensitivity. Root tips and zones of cell elongation were compared for each root type, using immunological probes for calmodulin, alpha-actin, alpha-tubulin, and proteins of the plastid envelope. Lateral roots contained qualitatively less calmodulin, and showed a slightly different pattern of actin-related epitope proteins, than did primary root tissues, suggesting that polypeptide differences may contribute to the gravitational sensitivity which these root types express.

  3. Effect of ultrasound pre-treatment on the drying kinetics of brown seaweed Ascophyllum nodosum.

    Science.gov (United States)

    Kadam, Shekhar U; Tiwari, Brijesh K; O'Donnell, Colm P

    2015-03-01

    The effect of ultrasound pre-treatment on the drying kinetics of brown seaweed Ascophyllum nodosum under hot-air convective drying was investigated. Pretreatments were carried out at ultrasound intensity levels ranging from 7.00 to 75.78 Wcm(-2) for 10 min using an ultrasonic probe system. It was observed that ultrasound pre-treatments reduced the drying time required. The shortest drying times were obtained from samples pre-treated at 75.78 Wcm(-2). The fit quality of 6 thin-layer drying models was also evaluated using the determination of coefficient (R(2)), root means square error (RMSE), AIC (Akaike information criterion) and BIC (Bayesian information criterion). Drying kinetics were modelled using the Newton, Henderson and Pabis, Page, Wang and Singh, Midilli et al. and Weibull models. The Newton, Wang and Singh, and Midilli et al. models showed the best fit to the experimental drying data. Color of ultrasound pretreated dried seaweed samples were lighter compared to control samples. It was concluded that ultrasound pretreatment can be effectively used to reduce the energy cost and drying time for drying of A. nodosum. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. 78 FR 13402 - Proposed Collection; Comment Request for Tip Reporting Alternative Tip Agreement Used in the...

    Science.gov (United States)

    2013-02-27

    ... Used in the Cosmetology and Barber Industry AGENCY: Internal Revenue Service (IRS), Treasury. ACTION..., the IRS is soliciting comments concerning tip reporting alternative commitment used in the cosmetology...: Tip Reporting Alternative Commitment Agreement used in the Cosmetology and Barber Industry. OMB Number...

  5. 75 FR 11226 - Proposed Collection; Comment Request for Tip Reporting Alternative Tip Agreement Used in the...

    Science.gov (United States)

    2010-03-10

    ... Used in the Cosmetology and Barber Industry AGENCY: Internal Revenue Service (IRS), Treasury. ACTION..., the IRS is soliciting comments concerning Tip Reporting Alternative Commitment used in the Cosmetology...: Tip Reporting Alternative Commitment Agreement used in the Cosmetology and Barber Industry. OMB Number...

  6. Intraspecific variation in root and leaf traits and leaf-root trait linkages in eight aspen demes (Populus tremula and P. tremuloides

    Directory of Open Access Journals (Sweden)

    Peter eHajek

    2013-10-01

    Full Text Available Leaf and fine root morphology and physiology have been found to vary considerably among tree species, but not much is known about intraspecific variation in root traits and their relatedness to leaf traits. Various aspen progenies (Populus tremula and P. tremuloides with different growth performance are used in short-rotation forestry. Hence, a better understanding of the link between root trait syndromes and the adaptation of a deme to a particular environment is essential in order to improve the match between planted varieties and their growth conditions. We examined the between-deme (genetic and within-deme (mostly environmental variation in important fine root traits [mean root diameter, specific root area (SRA and specific root length (SRL, root tissue density (RTD, root tip abundance, root N concentration] and their co-variation with leaf traits [specific leaf area (SLA, leaf size, leaf N concentration] in eight genetically distinct P. tremula and P. tremuloides demes. Five of the six root traits varied significantly between the demes with largest genotypic variation in root tip abundance and lowest in mean root diameter and RTD (no significant difference. Within-deme variation in root morphology was as large as between-deme variation suggesting a relatively low genetic control. Significant relationships existed neither between SLA and SRA nor between leaf N and root N concentration in a plant. Contrary to expectation, high aboveground relative growth rates (RGR were associated with large, and not small, fine root diameters with low SRA and SRL. Compared to leaf traits, the influence of root traits on RGR was generally low. We conclude that aspen exhibits large intraspecific variation in leaf and also in root morphological traits which is only partly explained by genetic distances. A root order-related analysis might give deeper insights into intraspecific root trait variation.

  7. Enhanced root production in Haplopappus gracilis grown under spaceflight conditions

    Science.gov (United States)

    Levine, H. G.; Krikorian, A. D.

    1996-01-01

    The production and growth of roots in two aseptically maintained clonal populations of Haplopappus gracilis (family Compositae), each with a distinctive pattern of root production, were studied after they had been exposed to space for 5 days aboard a NASA Space Shuttle. Total root production of both populations was 67-95% greater when compared with their Earth-grown controls. Roots were generated: (1) laterally from pre-formed roots, the tips of which had been severed at the time of plantlet insertion into a "horticultural foam" substrate supplied with a nutrient solution; (2) adventitiously from the basal or cut-end portion of shoots; (3) de novo, i.e. from primordial which were non-existent at the outset of the experiment. Roots grew in all directions in space but were uniformly positively gravitropic in ground controls. In space and on Earth, both clonal populations maintained their clone-specific root formation and growth characteristics and produced an equivalent amount of tissue when compared to each other. As on Earth, and as expected, there were fewer and shorter roots on plantlets that formed floral buds. The significance of altered moisture distribution in the "horticultural foam" substrate in space for root growth and the significance of our findings for growing plants in altered gravity environments are discussed.

  8. The evolution of root hairs and rhizoids

    Science.gov (United States)

    Jones, Victor A.S.; Dolan, Liam

    2012-01-01

    Background Almost all land plants develop tip-growing filamentous cells at the interface between the plant and substrate (the soil). Root hairs form on the surface of roots of sporophytes (the multicellular diploid phase of the life cycle) in vascular plants. Rhizoids develop on the free-living gametophytes of vascular and non-vascular plants and on both gametophytes and sporophytes of the extinct rhyniophytes. Extant lycophytes (clubmosses and quillworts) and monilophytes (ferns and horsetails) develop both free-living gametophytes and free-living sporophytes. These gametophytes and sporophytes grow in close contact with the soil and develop rhizoids and root hairs, respectively. Scope Here we review the development and function of rhizoids and root hairs in extant groups of land plants. Root hairs are important for the uptake of nutrients with limited mobility in the soil such as phosphate. Rhizoids have a variety of functions including water transport and adhesion to surfaces in some mosses and liverworts. Conclusions A similar gene regulatory network controls the development of rhizoids in moss gametophytes and root hairs on the roots of vascular plant sporophytes. It is likely that this gene regulatory network first operated in the gametophyte of the earliest land plants. We propose that later it functioned in sporophytes as the diploid phase evolved a free-living habit and developed an interface with the soil. This transference of gene function from gametophyte to sporophyte could provide a mechanism that, at least in part, explains the increase in morphological diversity of sporophytes that occurred during the radiation of land plants in the Devonian Period. PMID:22730024

  9. Comparing root architectural models

    Science.gov (United States)

    Schnepf, Andrea; Javaux, Mathieu; Vanderborght, Jan

    2017-04-01

    Plant roots play an important role in several soil processes (Gregory 2006). Root architecture development determines the sites in soil where roots provide input of carbon and energy and take up water and solutes. However, root architecture is difficult to determine experimentally when grown in opaque soil. Thus, root architectural models have been widely used and been further developed into functional-structural models that are able to simulate the fate of water and solutes in the soil-root system (Dunbabin et al. 2013). Still, a systematic comparison of the different root architectural models is missing. In this work, we focus on discrete root architecture models where roots are described by connected line segments. These models differ (a) in their model concepts, such as the description of distance between branches based on a prescribed distance (inter-nodal distance) or based on a prescribed time interval. Furthermore, these models differ (b) in the implementation of the same concept, such as the time step size, the spatial discretization along the root axes or the way stochasticity of parameters such as root growth direction, growth rate, branch spacing, branching angles are treated. Based on the example of two such different root models, the root growth module of R-SWMS and RootBox, we show the impact of these differences on simulated root architecture and aggregated information computed from this detailed simulation results, taking into account the stochastic nature of those models. References Dunbabin, V.M., Postma, J.A., Schnepf, A., Pagès, L., Javaux, M., Wu, L., Leitner, D., Chen, Y.L., Rengel, Z., Diggle, A.J. Modelling root-soil interactions using three-dimensional models of root growth, architecture and function (2013) Plant and Soil, 372 (1-2), pp. 93 - 124. Gregory (2006) Roots, rhizosphere and soil: the route to a better understanding of soil science? European Journal of Soil Science 57: 2-12.

  10. Method for pretreating lignocellulosic biomass

    Science.gov (United States)

    Kuzhiyil, Najeeb M.; Brown, Robert C.; Dalluge, Dustin Lee

    2015-08-18

    The present invention relates to a method for pretreating lignocellulosic biomass containing alkali and/or alkaline earth metal (AAEM). The method comprises providing a lignocellulosic biomass containing AAEM; determining the amount of the AAEM present in the lignocellulosic biomass; identifying, based on said determining, the amount of a mineral acid sufficient to completely convert the AAEM in the lignocellulosic biomass to thermally-stable, catalytically-inert salts; and treating the lignocellulosic biomass with the identified amount of the mineral acid, wherein the treated lignocellulosic biomass contains thermally-stable, catalytically inert AAEM salts.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. A bell pepper cultivar tolerant to chilling enhanced nitrogen allocation and stress-related metabolite accumulation in the roots in response to low root-zone temperature.

    Science.gov (United States)

    Aidoo, Moses Kwame; Sherman, Tal; Lazarovitch, Naftali; Fait, Aaron; Rachmilevitch, Shimon

    2017-10-01

    Two bell pepper (Capsicum annuum) cultivars, differing in their response to chilling, were exposed to three levels of root-zone temperatures. Gas exchange, shoot and root phenology, and the pattern of change of the central metabolites and secondary metabolites caffeate and benzoate in the leaves and roots were profiled. Low root-zone temperature significantly inhibited gaseous exchange, with a greater effect on the sensitive commercial pepper hybrid (Canon) than on the new hybrid bred to enhance abiotic stress tolerance (S103). The latter was less affected by the treatment with respect to plant height, shoot dry mass, root maximum length, root projected area, number of root tips and root dry mass. More carbon was allocated to the leaves of S103 than nitrogen at 17°C, while in the roots at 17°C, more nitrogen was allocated and the ratio between C/N decreased. Metabolite profiling showed greater increase in the root than in the leaves. Leaf response between the two cultivars differed significantly. The roots accumulated stress-related metabolites including γ-aminobutyric acid (GABA), proline, galactinol and raffinose and at chilling (7°C) resulted in an increase of sugars in both cultivars. Our results suggest that the enhanced tolerance of S103 to root cold stress, reflected in the relative maintenance of shoot and root growth, is likely linked to a more effective regulation of photosynthesis facilitated by the induction of stress-related metabolism. © 2017 Scandinavian Plant Physiology Society.

  13. Antisense expression of an Arabidopsis ran binding protein renders transgenic roots hypersensitive to auxin and alters auxin-induced root growth and development by arresting mitotic progress

    Science.gov (United States)

    Kim, S. H.; Arnold, D.; Lloyd, A.; Roux, S. J.

    2001-01-01

    We cloned a cDNA encoding an Arabidopsis Ran binding protein, AtRanBP1c, and generated transgenic Arabidopsis expressing the antisense strand of the AtRanBP1c gene to understand the in vivo functions of the Ran/RanBP signal pathway. The transgenic plants showed enhanced primary root growth but suppressed growth of lateral roots. Auxin significantly increased lateral root initiation and inhibited primary root growth in the transformants at 10 pM, several orders of magnitude lower than required to induce these responses in wild-type roots. This induction was followed by a blockage of mitosis in both newly emerged lateral roots and in the primary root, ultimately resulting in the selective death of cells in the tips of both lateral and primary roots. Given the established role of Ran binding proteins in the transport of proteins into the nucleus, these findings are consistent with a model in which AtRanBP1c plays a key role in the nuclear delivery of proteins that suppress auxin action and that regulate mitotic progress in root tips.

  14. Tip vortices in the actuator line model

    Science.gov (United States)

    Martinez, Luis; Meneveau, Charles

    2017-11-01

    The actuator line model (ALM) is a widely used tool to represent the wind turbine blades in computational fluid dynamics without the need to resolve the full geometry of the blades. The ALM can be optimized to represent the `correct' aerodynamics of the blades by choosing an appropriate smearing length scale ɛ. This appropriate length scale creates a tip vortex which induces a downwash near the tip of the blade. A theoretical frame-work is used to establish a solution to the induced velocity created by a tip vortex as a function of the smearing length scale ɛ. A correction is presented which allows the use of a non-optimal smearing length scale but still provides the downwash which would be induced using the optimal length scale. Thanks to the National Science Foundation (NSF) who provided financial support for this research via Grants IGERT 0801471, IIA-1243482 (the WINDINSPIRE project) and ECCS-1230788.

  15. Tipping elements in the Arctic marine ecosystem.

    Science.gov (United States)

    Duarte, Carlos M; Agustí, Susana; Wassmann, Paul; Arrieta, Jesús M; Alcaraz, Miquel; Coello, Alexandra; Marbà, Núria; Hendriks, Iris E; Holding, Johnna; García-Zarandona, Iñigo; Kritzberg, Emma; Vaqué, Dolors

    2012-02-01

    The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem.

  16. Estimation of surgical tool-tip tracking error distribution in coordinate reference frame involving pivot calibration uncertainty.

    Science.gov (United States)

    Min, Zhe; Ren, Hongliang; Meng, Max Q-H

    2017-10-01

    Accurate understanding of surgical tool-tip tracking error is important for decision making in image-guided surgery. In this Letter, the authors present a novel method to estimate/model surgical tool-tip tracking error in which they take pivot calibration uncertainty into consideration. First, a new type of error that is referred to as total target registration error (TTRE) is formally defined in a single-rigid registration. Target localisation error (TLE) in two spaces to be registered is considered in proposed TTRE formulation. With first-order approximation in fiducial localisation error (FLE) or TLE magnitude, TTRE statistics (mean, covariance matrix and root-mean-square (RMS)) are then derived. Second, surgical tool-tip tracking error in optical tracking system (OTS) frame is formulated using TTRE when pivot calibration uncertainty is considered. Finally, TTRE statistics of tool-tip in OTS frame are then propagated relative to a coordinate reference frame (CRF) rigid-body. Monte Carlo simulations are conducted to validate the proposed error model. The percentage passing statistical tests that there is no difference between simulated and theoretical mean and covariance matrix of tool-tip tracking error in CRF space is more than 90% in all test cases. The RMS percentage difference between simulated and theoretical tool-tip tracking error in CRF space is within 5% in all test cases.

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

    Directory of Open Access Journals (Sweden)

    K. S. Nagesh

    2008-09-01

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

  18. Nitrogen for growth of stock plants and production of strawberry runner tips

    Directory of Open Access Journals (Sweden)

    Djeimi Isabel Janisch

    2012-01-01

    Full Text Available The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control, 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested were collected weekly and counted during the growth period. The number of leaves, dry matter (DM of leaves, crown and root, specific leaf area and leaf area index (LAI was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.

  19. Rhizosphere microbial community structure in relation to root location and plant iron nutritional status.

    Science.gov (United States)

    Yang, C H; Crowley, D E

    2000-01-01

    Root exudate composition and quantity vary in relation to plant nutritional status, but the impact of the differences on rhizosphere microbial communities is not known. To examine this question, we performed an experiment with barley (Hordeum vulgare) plants under iron-limiting and iron-sufficient growth conditions. Plants were grown in an iron-limiting soil in root box microcosms. One-half of the plants were treated with foliar iron every day to inhibit phytosiderophore production and to alter root exudate composition. After 30 days, the bacterial communities associated with different root zones, including the primary root tips, nonelongating secondary root tips, sites of lateral root emergence, and older roots distal from the tip, were characterized by using 16S ribosomal DNA (rDNA) fingerprints generated by PCR-denaturing gradient gel electrophoresis (DGGE). Our results showed that the microbial communities associated with the different root locations produced many common 16S rDNA bands but that the communities could be distinguished by using correspondence analysis. Approximately 40% of the variation between communities could be attributed to plant iron nutritional status. A sequence analysis of clones generated from a single 16S rDNA band obtained at all of the root locations revealed that there were taxonomically different species in the same band, suggesting that the resolving power of DGGE for characterization of community structure at the species level is limited. Our results suggest that the bacterial communities in the rhizosphere are substantially different in different root zones and that a rhizosphere community may be altered by changes in root exudate composition caused by changes in plant iron nutritional status.

  20. Tip-Based Nanofabrication for Scalable Manufacturing

    Directory of Open Access Journals (Sweden)

    Huan Hu

    2017-03-01

    Full Text Available Tip-based nanofabrication (TBN is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. In this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

  1. Social tipping points and Earth systems dynamics

    Directory of Open Access Journals (Sweden)

    R. Alexander eBentley

    2014-08-01

    Full Text Available Recently, Early Warning Signals (EWS have been developed to predict tipping points in Earth Systems. This discussion highlights the potential to apply EWS to human social and economic systems, which may also undergo similar critical transitions. Social tipping points are particularly difficult to predict, however, and the current formulation of EWS, based on a physical system analogy, may be insufficient. As an alternative set of EWS for social systems, we join with other authors encouraging a focus on heterogeneity, connectivity through social networks and individual thresholds to change.

  2. Windows 7 Annoyances Tips, Secrets, and Solutions

    CERN Document Server

    Karp, David

    2010-01-01

    Windows 7 may be faster and more stable than Vista, but it's a far cry from problem-free. David A. Karp comes to the rescue with the latest in his popular Windows Annoyances series. This thorough guide gives you the tools you need to fix the troublesome parts of this operating system, plus the solutions, hacks, and timesaving tips to make the most of your PC. Streamline Windows Explorer, improve the Search tool, eliminate the Green Ribbon of Death, and tame User Account Control promptsExplore powerful Registry tips and tools, and use them to customize every aspect of Windows and solve its sho

  3. Relationships between root diameter, root length and root branching along lateral roots in adult, field-grown maize

    OpenAIRE

    Wu, Qian; Pag?s, Lo?c; Wu, Jie

    2016-01-01

    Background and Aims Root diameter, especially apical diameter, plays an important role in root development and function. The variation in diameter between roots, and along roots, affects root structure and thus the root system?s overall foraging performance. However, the effect of diameter variation on root elongation, branching and topological connections has not been examined systematically in a population of high-order roots, nor along the roots, especially for mature plants grown in the f...

  4. A 30 mK, 13.5 T scanning tunneling microscope with two independent tips

    Science.gov (United States)

    Roychowdhury, Anita; Gubrud, M. A.; Dana, R.; Anderson, J. R.; Lobb, C. J.; Wellstood, F. C.; Dreyer, M.

    2014-04-01

    We describe the design, construction, and performance of an ultra-low temperature, high-field scanning tunneling microscope (STM) with two independent tips. The STM is mounted on a dilution refrigerator and operates at a base temperature of 30 mK with magnetic fields of up to 13.5 T. We focus on the design of the two-tip STM head, as well as the sample transfer mechanism, which allows in situ transfer from an ultra high vacuum preparation chamber while the STM is at 1.5 K. Other design details such as the vibration isolation and rf-filtered wiring are also described. Their effectiveness is demonstrated via spectral current noise characteristics and the root mean square roughness of atomic resolution images. The high-field capability is shown by the magnetic field dependence of the superconducting gap of CuxBi2Se3. Finally, we present images and spectroscopy taken with superconducting Nb tips with the refrigerator at 35 mK that indicate that the effective temperature of our tips/sample is approximately 184 mK, corresponding to an energy resolution of 16 μeV.

  5. A Deep-Learning System for Fully-Automated Peripherally Inserted Central Catheter (PICC) Tip Detection.

    Science.gov (United States)

    Lee, Hyunkwang; Mansouri, Mohammad; Tajmir, Shahein; Lev, Michael H; Do, Synho

    2017-10-05

    A peripherally inserted central catheter (PICC) is a thin catheter that is inserted via arm veins and threaded near the heart, providing intravenous access. The final catheter tip position is always confirmed on a chest radiograph (CXR) immediately after insertion since malpositioned PICCs can cause potentially life-threatening complications. Although radiologists interpret PICC tip location with high accuracy, delays in interpretation can be significant. In this study, we proposed a fully-automated, deep-learning system with a cascading segmentation AI system containing two fully convolutional neural networks for detecting a PICC line and its tip location. A preprocessing module performed image quality and dimension normalization, and a post-processing module found the PICC tip accurately by pruning false positives. Our best model, trained on 400 training cases and selectively tuned on 50 validation cases, obtained absolute distances from ground truth with a mean of 3.10 mm, a standard deviation of 2.03 mm, and a root mean squares error (RMSE) of 3.71 mm on 150 held-out test cases. This system could help speed confirmation of PICC position and further be generalized to include other types of vascular access and therapeutic support devices.

  6. Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits

    Science.gov (United States)

    Wang, Yan-Liang; Almvik, Marit; Clarke, Nicholas; Eich-Greatorex, Susanne; Øgaard, Anne Falk; Krogstad, Tore; Lambers, Hans; Clarke, Jihong Liu

    2015-01-01

    Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids (OAs) to low available P (1 μM P) and sufficient P (50 μM P) in barley, canola and micropropagated seedlings of potato—three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area and an increase in root-exuded malic acid under low-P conditions. Potato exuded relatively small amounts of OAs under low P, while there was a marked increase in root tips. Based on the results, we conclude that different crops show divergent morphological and physiological responses to low P availability, having evolved specific traits of root morphology and root exudation that enhance their P-uptake capacity under low-P conditions. These results could underpin future efforts to improve P uptake of the three crops that are of importance for future sustainable crop production. PMID:26286222

  7. Dielectrophoretic positioning of single nanoparticles on atomic force microscope tips for tip-enhanced Raman spectroscopy.

    Science.gov (United States)

    Leiterer, Christian; Deckert-Gaudig, Tanja; Singh, Prabha; Wirth, Janina; Deckert, Volker; Fritzsche, Wolfgang

    2015-05-01

    Tip-enhanced Raman spectroscopy, a combination of Raman spectroscopy and scanning probe microscopy, is a powerful technique to detect the vibrational fingerprint of molecules at the nanometer scale. A metal nanoparticle at the apex of an atomic force microscope tip leads to a large enhancement of the electromagnetic field when illuminated with an appropriate wavelength, resulting in an increased Raman signal. A controlled positioning of individual nanoparticles at the tip would improve the reproducibility of the probes and is quite demanding due to usually serial and labor-intensive approaches. In contrast to commonly used submicron manipulation techniques, dielectrophoresis allows a parallel and scalable production, and provides a novel approach toward reproducible and at the same time affordable tip-enhanced Raman spectroscopy tips. We demonstrate the successful positioning of an individual plasmonic nanoparticle on a commercial atomic force microscope tip by dielectrophoresis followed by experimental proof of the Raman signal enhancing capabilities of such tips. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tip off the HAT- Epigenetic control of learning and memory by Drosophila Tip60.

    Science.gov (United States)

    Xu, Songjun; Elefant, Felice

    2015-01-01

    Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders.

  9. Soil sheaths, photosynthate distribution to roots, and rhizosphere water relations for Opuntia ficus-indica

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.; North, G.B.; Nobel, P.S. (Univ. of California, Los Angeles, CA (United States))

    1993-09-01

    Soil sheaths incorporating aggregated soil particles surround young roots of many species, but the effects of such sheaths on water movement between roots and the soil are largely unknown. The quantity and location of root exudates associated with soil sheath along the entire length of its young roots, except within 1.4 cm of the tip. The soil sheaths, which average 0.7 mm in thickness, were composed of soil particles and root hairs, both of which were covered with exuded mucilaginous material. As determined with a [sup 14]C pulse-labeling technique, 2% of newly fixed [sup 14]C-photosynthate was translocated into the roots at 3d, 6% at 9 d, and 8% at 15 d after labeling. The fraction of insoluble [sup 14]C in the roots increased twofold from 3 d to 15 d. Over the same time period, 6%-9% of the [sup 14]C translocated to the roots was exuded into the soil. The soluble [sup 14]C compounds exuded into the soil were greater in the 3-cm segment at the root tip than elsewhere along the root, whereas mucilage was exuded relatively uniformly along roots 15 cm in length. The volumetric efflux of water increase for both sheathed and unsheathed roots as the soil water potential decreased form -0.1 MPa to -1.0 MPa. The efflux rate was greater for unsheathed roots than for sheathed roots, which were more turgid and had a higher water potential, especially at lower soil water potentials. During drying, soil particles in the sheaths aggregate more tightly, making the sheaths less permeable to water and possibly creating air gaps. The soil sheaths of O. ficus-indica thus reduce water loss from the roots to a drying soil. 34 refs., 6 figs., 1 tab.

  10. Tooth Eruption without Roots

    OpenAIRE

    Wang, X.-P.

    2013-01-01

    Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the diffic...

  11. Neutron tomography of the root-soil interface: water distribution around different parts of the root structure

    Science.gov (United States)

    Moradi, A. B.; Carminati, A.

    2009-12-01

    Although the importance of the root-soil interface in water uptake by plant roots has been acknowledged in many studies, there is a gap of knowledge on how water enters the roots. The main reason for this gap is the technical difficulties in resolving soil moisture dynamics in the vicinity of roots. Spatially and temporally resolved data on water flow across soil-root interface is needed to improve our understanding of mechanisms controlling water uptake by roots. We used neutron tomography to image soil water distribution around roots in-situ. We grew chick peas and lupines in sand-filled cylinders for 10 days at a water potential of -20 hPa. The samples were tomographed for 4 days over day and night and during a drying period and after rewetting. We observed that water content near the root surface was higher than in the bulk soil during the whole course of measurement for all the samples. Our hypothesis is that this increase of water content next to roots was due to the distinct water retention curve of the soil next to roots, the rhizosphere. Our hypothesis is that the rhizosphere water retention curve is caused by mucilage exuded by roots. Mucilage contains more than 90% water even at low water potentials, consequently increasing the water holding capacity of the rhizosphere. In another words, the roots modify the physical and chemical properties of their rhizosphere. The thickness of the area of increasing water, rhizosphere, varied along the root length. It ranged from slightly less than 1.5 mm in the distal part of the roots to more than 3 mm around the root tip. Also, it was slightly thicker around the main root compared to the lateral roots. As the soil water was being consumed by the roots, the extent of the rhizosphere decreased slightly, and then increased again after rewetting. We expect that the high water-holding capacity of the rhizosphere favors root water uptake, especially in dry soils. Most of the present modeling approaches neglect this effect.

  12. Damage to the root after tooth movement towards a temporary anchorage device: An animal pilot study

    Directory of Open Access Journals (Sweden)

    Cheng-Tsung Huang

    2012-06-01

    Conclusions: A root moving towards a screw during OTM leads to crater-like damage. When time was allowed for healing, a trace of labeled cementum was found to have repaired the root surface, although a large portion of the concavity was filled in with alveolar bone, and the periodontal ligament space remained constant. A root moving against a screw produced excessive tipping. To avoid deviation from the predicted biomechanics and damage to the root, extra caution should be used to ensure the best benefits for patients when TADs are used interdentally for distalization of the dentition during orthodontic treatment.

  13. Root production method system

    Science.gov (United States)

    Wayne Lovelace

    2002-01-01

    The RPM system (Root Production Method) is a multistep production system of container tree production that places primary emphasis on the root system because the root system ultimately determines the tree's survival and performance in its outplanted environment. This particular container production system has been developed to facilitate volume production, in a...

  14. Armillaria root rot

    Science.gov (United States)

    First described on grapevines in California in the 1880s, Armillaria root rot occurs in all major grape-growing regions of the state. The causal fungus, Armillaria mellea, infects woody grapevine roots and the base of the trunk (the root collar), resulting in a slow decline and eventual death of the...

  15. Root canal irrigation

    NARCIS (Netherlands)

    van der Sluis, L.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, L.E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root

  16. The Root Canal Biofilm

    NARCIS (Netherlands)

    van der Sluis, L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, Michel; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root

  17. Two similar enhanced root-colonizing Pseudomonas strains differ largely in their colonization strategies of avocado roots and Rosellinia necatrix hyphae.

    Science.gov (United States)

    Pliego, Clara; de Weert, Sandra; Lamers, Gerda; de Vicente, Antonio; Bloemberg, Guido; Cazorla, Francisco Manuel; Ramos, Cayo

    2008-12-01

    Pseudomonas alcaligenes AVO73 and Pseudomonas pseudoalcaligenes AVO110 were selected previously as efficient avocado root tip colonizers, displaying in vitro antagonism towards Rosellinia necatrix, causal agent of avocado white root rot. Despite the higher number of antagonistic properties shown in vitro by AVO73, only AVO110 demonstrated significant protection against avocado white root rot. As both strains are enhanced root colonizers, and as colonization is crucial for the most likely biocontrol mechanisms used by these strains, namely production of non-antibiotic antifungal compounds and competition for nutrients and niches, we decided to compare the interactions of the bacterial strains with avocado roots as well as with R. necatrix hyphae. The results indicate that strain AVO110 is superior in biocontrol trait swimming motility and establishes on the root tip of avocado plants faster than AVO73. Visualization studies, using Gfp-labelled derivatives of these strains, showed that AVO110, in contrast to AVO73, colonizes intercellular crevices between neighbouring plant root epidermal cells, a microhabitat of enhanced exudation. Moreover, AVO110, but not AVO73, also colonizes root wounds, described to be preferential penetration sites for R. necatrix infection. This result strongly suggests that AVO110 meets, and can attack, the pathogen on the root. Finally, when co-inoculated with the pathogen, AVO110 utilizes hyphal exudates more efficiently for proliferation than AVO73 does, and colonizes the hyphae more abundantly than AVO73. We conclude that the differences between the strains in colonization levels and strategies are likely to contribute to, and even can explain, the difference in disease-controlling abilities between the strains. This is the first report that shows that two similar bacterial strains, selected by their ability to colonize avocado root, use strongly different root colonization strategies and suggests that in addition to the total bacterial

  18. In vitro performance of DIAGNOdent laser fluorescence device for dental calculus detection on human tooth root surfaces.

    Science.gov (United States)

    Rams, Thomas E; Alwaqyan, Abdulaziz Y

    2017-10-01

    This study assessed the reproducibility of a red diode laser device, and its capability to detect dental calculus in vitro on human tooth root surfaces. On each of 50 extracted teeth, a calculus-positive and calculus-free root surface was evaluated by two independent examiners with a low-power indium gallium arsenide phosphide diode laser (DIAGNOdent) fitted with a periodontal probe-like sapphire tip and emitting visible red light at 655 nm wavelength. Laser autofluorescence intensity readings of examined root surfaces were scored on a 0-99 scale, with duplicate assessments performed using the laser probe tip directed both perpendicular and parallel to evaluated tooth root surfaces. Pearson correlation coefficients of untransformed measurements, and kappa analysis of data dichotomized with a >40 autofluorescence intensity threshold, were calculated to assess intra- and inter-examiner reproducibility of the laser device. Mean autofluorescence intensity scores of calculus-positive and calculus-free root surfaces were evaluated with the Student's t -test. Excellent intra- and inter-examiner reproducibility was found for DIAGNOdent laser autofluorescence intensity measurements, with Pearson correlation coefficients above 94%, and kappa values ranging between 0.96 and 1.0, for duplicate readings taken with both laser probe tip orientations. Significantly higher autofluorescence intensity values were measured when the laser probe tip was directed perpendicular, rather than parallel, to tooth root surfaces. However, calculus-positive roots, particularly with calculus in markedly-raised ledges, yielded significantly greater mean DIAGNOdent laser autofluorescence intensity scores than calculus-free surfaces, regardless of probe tip orientation. DIAGNOdent autofluorescence intensity values >40 exhibited a stronger association with calculus (36.6 odds ratio) then measurements of ≥5 (20.1 odds ratio) when the laser probe tip was advanced parallel to root surfaces. Excellent

  19. Adipogenesis: forces that tip the scales

    DEFF Research Database (Denmark)

    MacDougald, Ormond A; Mandrup, Susanne

    2001-01-01

    factors reviewed include Wnt, transforming growth factor beta, inflammatory cytokines and prostaglandin F(2alpha). Tipping the scales towards or away from adipogenesis has profound implications for human health. In this review, we describe recent contributions to the field and will focus on factors...

  20. Tip Saves Energy, Money for Pennsylvania Plant

    Science.gov (United States)

    A wastewater treatment plant in Berks County, Pennsylvania is saving nearly $45,000 a year and reducing hundreds of metric tons of greenhouse gases since employing an energy conservation tip offered by the Water Protection Division in EPA’s R3 and PADEP.

  1. International Travel: Tips for Staying Healthy

    Science.gov (United States)

    ... Conditions Prevention and Wellness Staying Healthy Healthy Living Travel Occupational Health First Aid and Injury Prevention Crisis ... MoreDepression in Children and TeensRead MoreBMI Calculator Air Travel Health TipsTexting and DrivingTravel Needs for SeniorsFood PoisoningAcute ...

  2. Barbecue Basics: Tips to Prevent Foodborne Illness

    Medline Plus

    Full Text Available ... Español Search FDA Submit search Popular Content Home Food Drugs Medical Devices Radiation-Emitting Products Vaccines, ... Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Updates Barbecue Basics: Tips to ...

  3. What Do You Mean, 'Tipping Point'?

    NARCIS (Netherlands)

    Nes, van E.H.; Shojaei Arani, M.; Staal, A.; Bolt, van der B.; Flores, Bernardo M.; Bathiany, S.; Scheffer, M.

    2016-01-01

    Over the past 10 years the use of the term ‘tipping point’ in the scientific literature has exploded. It was originally used loosely as a metaphor for the phenomenon that, beyond a certain threshold, runaway change propels a system to a new state. Although several specific mathematical definitions

  4. Direct calculation of wind turbine tip loss

    DEFF Research Database (Denmark)

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

    2016-01-01

    . We develop three methods for the direct calculation of the tip loss. The first is the computationally expensive calculation of the velocities induced by the helicoidal wake which requires the evaluation of infinite sums of products of Bessel functions. The second uses the asymptotic evaluation...

  5. The Tipping Points of Technology Development

    Directory of Open Access Journals (Sweden)

    Tauno Kekäle

    2014-07-01

    Full Text Available The tipping point, the decisive point in time in the competition between old and new, is an interesting phenomenon in physics of today. This aspect in technology acceptance is connected to many business decisions such as technology investments, product releases, resource allocation, sales forecasts and, ultimately, affects the profitability and even survival of a company. The tipping point itself is based on many stochastic and dynamic variables, and the process may at least partly be described as path-dependent. This paper analyses the tipping point from three aspects: (1 product performance, (2 features of the market and infrastructure (including related technologies and human network externalities, and (3 actions of the incumbents (including customer lock-in, systems lock-in, and sustaining innovation. The paper is based on the Bass s-curve idea and the technology trajectory concept proposed by Dosi. Three illustrative cases are presented to make the point of the multiple factors affecting technology acceptance and, thus, the tipping point. The paper also suggests outlines for further research in field of computer simulation.

  6. Tips for Airline Travelers with Sjogren's Syndrome

    Science.gov (United States)

    Tips for Airline Travelers with Sjögren’s Syndrome For more information on Sjogren's syndrome, visit the SSF Web site at www.sjogrens. ... org for more information on Sjögren’s syndrome. New airline rules can have a profound effect on those ...

  7. Final Technical Report: Electrohydrodynamic Tip Streaming

    Energy Technology Data Exchange (ETDEWEB)

    Basaran, Osman [Purdue Univ., West Lafayette, IN (United States)

    2016-01-06

    When subjected to strong electric fields, liquid drops and films form conical tips and emit thin jets from their tips. Such electrodydrodynamic (EDH) tip streaming or cone-jetting phenomena, which are sometimes referred to as electrospraying, occur widely in nature, e.g., in ejection of streams of small charged drops from pointed tips of raindrops in thunderclouds, and technology, e.g., in electrospray mass spectrometry or electric field-driven solvent extraction. More recently, EHD cone-jetting has emerged as a powerful technique for direct printing of solar cells, micro- and nano- particle production, and microencapsulation for controlled release. In many of the aforementioned situations, of equal importance to the processes by which one drop disintegrates to form several drops are those by which (a) two drops come together and coalesce and (b) two drops are coupled to form a double droplet system (DDS) or a capillary switch (CS). the main objective of this research program is to advance through simulation, theory, and experiment the breakup, coalescence, and oscillatory dynamics of single and pairs of charged as well as uncharged drops.

  8. Tip cells: master regulators of tubulogenesis?

    Science.gov (United States)

    Weavers, Helen; Skaer, Helen

    2014-07-01

    The normal development of an organ depends on the coordinated regulation of multiple cell activities. Focusing on tubulogenesis, we review the role of specialised cells or groups of cells that are selected from within tissue primordia and differentiate at the outgrowing tips or leading edge of developing tubules. Tip or leading cells develop distinctive patterns of gene expression that enable them to act both as sensors and transmitters of intercellular signalling. This enables them to explore the environment, respond to both tissue intrinsic signals and extrinsic cues from surrounding tissues and to regulate the behaviour of their neighbours, including the setting of cell fate, patterning cell division, inducing polarity and promoting cell movement and cell rearrangements by neighbour exchange. Tip cells are also able to transmit mechanical tension to promote tissue remodelling and, by interacting with the extracellular matrix, they can dictate migratory pathways and organ shape. Where separate tubular structures fuse to form networks, as in the airways of insects or the vascular system of vertebrates, specialised fusion tip cells act to interconnect disparate elements of the developing network. Finally, we consider their importance in the maturation of mature physiological function and in the development of disease. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Amelioration of bromobenzene hepatotoxicity by Withania somnifera pretreatment: Role of mitochondrial oxidative stress

    OpenAIRE

    Vedi, Mahima; Rasool, Mahaboobkhan; Sabina, Evan Prince

    2014-01-01

    The present study investigated the possible protective role of Withania somnifera (Linn.) Dunal (Solanaceae) root powder against bromobenzene-induced oxidative damage in rat liver mitochondria. Administration of bromobenzene (10 mmol/kg body weight) to rats resulted in increased levels of liver marker enzymes, lipid peroxidation, TNF-α, IL-1β and VEGF. There was also marked depletion in the levels of mitochondrial enzymes and antioxidant activity. Pre-treatment with W. somnifera significantly...

  10. Root and Nodulation Phenotypes of the Ethylene-Insensitive Sickle Mutant of Medicago truncatula

    Directory of Open Access Journals (Sweden)

    JOKO PRAYITNO

    2010-09-01

    Full Text Available The sickle (skl mutant of the model legume Medicago truncatula is an ethylene-sensitive mutant that have a ten-fold increase in nodule numbers. The nodulation and root phenotypes of the skl mutant were investigated and further characterised. The skl mutant had longer roots than the wild type, but when inoculated with Sinorhizobium, its root length was reduced to the level of wild type. Furthermore, lateral root numbers in uninoculated skl were similar to those in uninoculated wild type. However, when the root tips were decapitated, fewer lateral roots formed in skl than in wild type. Nodule numbers of the skl mutant were significantly reduced by low nitrate concentration (2.5 mM. These results suggest that skl mutant has alterations in both root and nodule development.

  11. Wash water waste pretreatment system

    Science.gov (United States)

    1977-01-01

    Investigations were completed on wash waters based on each candidate personal cleansing agent. Evaluations of coagulants, antifoam agents, and the effect of promising antifoams on the chemical precipitation were included. Based on these evaluations two candidate soaps as well as their companion antifoam agents were selected for further work. Operating parameters included the effect of soap concentration, ferric chloride concentration, duration of mixing, and pore size of depth filters on the degree of soap removal. The effect of pressure on water flow through filter cartridges and on the rate of decline of water flow was also investigated. The culmination of the program was the recommendation of a pretreatment concept based on chemical precipitation followed by pressure filtration.

  12. Study of tip loss corrections using CFD rotor computations

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zhu, Wei Jun; Sørensen, Jens Nørkær

    2014-01-01

    Tip loss correction is known to play an important role for engineering prediction of wind turbine performance. There are two different types of tip loss corrections: tip corrections on momentum theory and tip corrections on airfoil data. In this paper, we study the latter using detailed CFD compu...... and compared with CFD results for the NordTank 500 kW turbine and the NREL 5 MW turbine. Comparisons show that BEM with the new tip loss function can predict correctly the loading near the blade tip.......Tip loss correction is known to play an important role for engineering prediction of wind turbine performance. There are two different types of tip loss corrections: tip corrections on momentum theory and tip corrections on airfoil data. In this paper, we study the latter using detailed CFD...... computations for wind turbines with sharp tip. Using the technique of determination of angle of attack and the CFD results for a NordTank 500 kW rotor, airfoil data are extracted and a new tip loss function on airfoil data is derived. To validate, BEM computations with the new tip loss function are carried out...

  13. Adaptive root foraging strategies along a boreal-temperate forest gradient.

    Science.gov (United States)

    Ostonen, Ivika; Truu, Marika; Helmisaari, Heljä-Sisko; Lukac, Martin; Borken, Werner; Vanguelova, Elena; Godbold, Douglas L; Lõhmus, Krista; Zang, Ulrich; Tedersoo, Leho; Preem, Jens-Konrad; Rosenvald, Katrin; Aosaar, Jürgen; Armolaitis, Kęstutis; Frey, Jane; Kabral, Naima; Kukumägi, Mai; Leppälammi-Kujansuu, Jaana; Lindroos, Antti-Jussi; Merilä, Päivi; Napa, Ülle; Nöjd, Pekka; Parts, Kaarin; Uri, Veiko; Varik, Mats; Truu, Jaak

    2017-08-01

    The tree root-mycorhizosphere plays a key role in resource uptake, but also in the adaptation of forests to changing environments. The adaptive foraging mechanisms of ectomycorrhizal (EcM) and fine roots of Picea abies, Pinus sylvestris and Betula pendula were evaluated along a gradient from temperate to subarctic boreal forest (38 sites between latitudes 48°N and 69°N) in Europe. Variables describing tree resource uptake structures and processes (absorptive fine root biomass and morphology, nitrogen (N) concentration in absorptive roots, extramatrical mycelium (EMM) biomass, community structure of root-associated EcM fungi, soil and rhizosphere bacteria) were used to analyse relationships between root system functional traits and climate, soil and stand characteristics. Absorptive fine root biomass per stand basal area increased significantly from temperate to boreal forests, coinciding with longer and thinner root tips with higher tissue density, smaller EMM biomass per root length and a shift in soil microbial community structure. The soil carbon (C) : N ratio was found to explain most of the variability in absorptive fine root and EMM biomass, root tissue density, N concentration and rhizosphere bacterial community structure. We suggest a concept of absorptive fine root foraging strategies involving both qualitative and quantitative changes in the root-mycorrhiza-bacteria continuum along climate and soil C : N gradients. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  14. OsORC3 is required for lateral root development in rice.

    Science.gov (United States)

    Chen, Xinai; Shi, Jing; Hao, Xi; Liu, Huili; Shi, Jianghua; Wu, Yunrong; Wu, Zhongchang; Chen, Mingxiu; Wu, Ping; Mao, Chuanzao

    2013-04-01

    The origin recognition complex (ORC) is a pivotal element in DNA replication, heterochromatin assembly, checkpoint regulation and chromosome assembly. Although the functions of the ORC have been determined in yeast and model animals, they remain largely unknown in the plant kingdom. In this study, Oryza sativa Origin Recognition Complex subunit 3 (OsORC3) was cloned using map-based cloning procedures, and functionally characterized using a rice (Oryza sativa) orc3 mutant. The mutant showed a temperature-dependent defect in lateral root (LR) development. Map-based cloning showed that a G→A mutation in the 9th exon of OsORC3 was responsible for the mutant phenotype. OsORC3 was strongly expressed in regions of active cell proliferation, including the primary root tip, stem base, lateral root primordium, emerged lateral root primordium, lateral root tip, young shoot, anther and ovary. OsORC3 knockdown plants lacked lateral roots and had a dwarf phenotype. The root meristematic zone of ORC3 knockdown plants exhibited increased cell death and reduced vital activity compared to the wild-type. CYCB1;1::GUS activity and methylene blue staining showed that lateral root primordia initiated normally in the orc3 mutant, but stopped growing before formation of the stele and ground tissue. Our results indicate that OsORC3 plays a crucial role in the emergence of lateral root primordia. © 2013 The Authors The Plant Journal © 2013 Blackwell Publishing Ltd.

  15. Responses of Sugar Beet Roots to Iron Deficiency. Changes in Carbon Assimilation and Oxygen Use1

    Science.gov (United States)

    López-Millán, Ana Flor; Morales, Fermín; Andaluz, Sofía; Gogorcena, Yolanda; Abadía, Anunciación; Rivas, Javier De Las; Abadía, Javier

    2000-01-01

    Different root parts with or without increased iron-reducing activities have been studied in iron-deficient and iron-sufficient control sugar beet (Beta vulgaris L. Monohil hybrid). The distal root parts of iron-deficient plants, 0 to 5 mm from the root apex, were capable to reduce Fe(III)-chelates and contained concentrations of flavins near 700 μm, two characteristics absent in the 5 to 10 mm sections of iron-deficient plants and the whole root of iron-sufficient plants. Flavin-containing root tips had large pools of carboxylic acids and high activities of enzymes involved in organic acid metabolism. In iron-deficient yellow root tips there was a large increase in carbon fixation associated to an increase in phosphoenolpyruvate carboxylase activity. Part of this carbon was used, through an increase in mitochondrial activity, to increase the capacity to produce reducing power, whereas another part was exported via xylem. Root respiration was increased by iron deficiency. In sugar beet iron-deficient roots flavins would provide a suitable link between the increased capacity to produce reduced nucleotides and the plasma membrane associated ferric chelate reductase enzyme(s). Iron-deficient roots had a large oxygen consumption rate in the presence of cyanide and hydroxisalycilic acid, suggesting that the ferric chelate reductase enzyme is able to reduce oxygen in the absence of Fe(III)-chelates. PMID:11027736

  16. Ultra-morphology of root surface subsequent to periodontal instrumentation: A scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    Parveen Dahiya

    2012-01-01

    Full Text Available Background: The aim of this study was to compare root surface characteristic following root planing with various hand and power driven instruments. Materials and Methods: A total of 20 single rooted teeth were used in this study, of which two specimens were used as control (no instrumentation done and remaining 18 specimens were equally divided into three groups. Specimens from each group were then subjected to root planing by one of the following instruments: (1 a Gracey curette (2 Ultrasonic tip and (3 a Rotary bur. In each case, the time required for scaling and root planing was measured. After treatment, the specimens were observed under scanning electron microscope and surface roughness was measured by using Roughness and loss of tooth substance index (RLTSI. Results: The mean RLTSI scores for Gracey curette, ultrasonic and rotary instrument group were 2.5, 2.0 and 0.667 respectively. The mean scores of time spent for scaling and root planing by Gracey curette, ultrasonic and rotary instrument group in seconds were 42.50, 35.83 and 54.50. Conclusion: All the three instruments namely Gracey curette, Ultrasonic tip and Rotary bur were effective in mechanical debridement of root surface. The results favoured the use of rotary instruments for root planing to achieve smooth clean root surface; however, the use of rotary instrument was more time consuming which might limit its use in clinical practice.

  17. Pretreatment of the macroalgae Chaetomorpha linum for the production of bioethanol - Comparison of five pretreatment technologies

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Thygesen, Anders; Thomsen, Sune Tjalfe

    2013-01-01

    -assisted pretreatment (PAP) and ball milling (BM), to determine effects of the pretreatment methods on the conversion of C. linum into ethanol by simultaneous saccharification and fermentation (SSF). WO and BM showed the highest ethanol yield of 44. g ethanol/100. g glucan, which was close to the theoretical ethanol......A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma...... yield of 57. g ethanol/100. g glucan. A 64% higher ethanol yield, based on raw material, was reached after pretreatment with WO and BM compared with unpretreated C. linum, however 50% of the biomass was lost during WO. Results indicated that the right combination of pretreatment and marine macroalgae...

  18. Tips for Good Health in Later Life: For Older Women

    Science.gov (United States)

    ... Geriatrics Osteoporosis Prevention Related Documents PDF Tips for Good Health in Later Life: For Older Women Download Join our e-newsletter! Resources Tips for Good Health in Later Life: For Older Women Tools ...

  19. Tips to Make Fast Food Friendlier for Kids

    Science.gov (United States)

    ... Workplace Food and Beverage Toolkit Tips to Make Fast Food Friendlier for Kids Updated:Feb 6,2017 Finding ... reheated or eaten on the road. But when fast food is your only option, try these tips to ...

  20. Conserved regulatory mechanism controls the development of cells with rooting functions in land plants

    OpenAIRE

    Tam, Thomas Ho Yuen; Catarino, Bruno; Dolan, Liam

    2015-01-01

    This work describes the discovery of an ancient genetic mechanism that was used to build rooting systems when plants colonized the relatively dry continental surfaces >470 million years ago. We demonstrate that a group of basic helix–loop–helix transcription factors—the LOTUS JAPONICUS ROOTHAIRLESS1-LIKE proteins—is part of a conserved auxin-regulated gene network that controls the development of tip-growing cells with rooting functions among extant land plants. This result suggests that this...

  1. AFM tip-sample convolution effects for cylinder protrusions

    Science.gov (United States)

    Shen, Jian; Zhang, Dan; Zhang, Fei-Hu; Gan, Yang

    2017-11-01

    A thorough understanding about the AFM tip geometry dependent artifacts and tip-sample convolution effect is essential for reliable AFM topographic characterization and dimensional metrology. Using rigid sapphire cylinder protrusions (diameter: 2.25 μm, height: 575 nm) as the model system, a systematic and quantitative study about the imaging artifacts of four types of tips-two different pyramidal tips, one tetrahedral tip and one super sharp whisker tip-is carried out through comparing tip geometry dependent variations in AFM topography of cylinders and constructing the rigid tip-cylinder convolution models. We found that the imaging artifacts and the tip-sample convolution effect are critically related to the actual inclination of the working cantilever, the tip geometry, and the obstructive contacts between the working tip's planes/edges and the cylinder. Artifact-free images can only be obtained provided that all planes and edges of the working tip are steeper than the cylinder sidewalls. The findings reported here will contribute to reliable AFM characterization of surface features of micron or hundreds of nanometers in height that are frequently met in semiconductor, biology and materials fields.

  2. Mechanisms for enlarging lesion size during irrigated tip radiofrequency ablation

    DEFF Research Database (Denmark)

    Petersen, Helen Høgh; Roman-Gonzalez, Javier; Johnson, Susan B

    2004-01-01

    INTRODUCTION: Irrigated tip radiofrequency ablation of cardiac arrhythmias was developed to increase the size of the radiofrequency-induced lesion, since cooling of the electrode tip allows use of higher power settings. The purpose of this study was to determine if the increased lesion size during......(3) (P radiofrequency irrigated-tip ablation is that higher power levels can be used...

  3. Modular design of AFM probe with sputtered silicon tip

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Thaysen, Jacob; Bouwstra, Siebe

    2001-01-01

    of the thin films constituting the cantilever. The AFM probe has an integrated tip made of a thick sputtered silicon layer, which is deposited after the probe has been defined and just before the cantilevers are released. The tips are so-called rocket tips made by reactive ion etching. We present probes...

  4. Contribution of root cap mucilage and presence of an intact root cap in maize (Zea mays) to the reduction of soil mechanical impedance.

    Science.gov (United States)

    Iijima, Morio; Higuchi, Toshifumi; Barlow, Peter W

    2004-09-01

    The impedance to root growth imposed by soil can be decreased by both mucilage secretion and the sloughing of border cells from the root cap. The aim of this study is to quantify the contribution of these two factors for maize root growth in compact soil. These effects were evaluated by assessing growth after removing both mucilage (treatment I -- intact) and the root cap (treatment D -- decapped) from the root tip, and then by adding back 2 micro L of mucilage to both intact (treatment IM -- intact plus mucilage) and decapped (treatment DM -- decapped plus mucilage) roots. Roots were grown in either loose (0.9 Mg m(-3)) or compact (1.5 Mg m(-3)) loamy sand soils. Also examined were the effects of decapping on root penetration resistance at three soil bulk densities (1.3, 1.4 and 1.5 Mg m(-3)). In treatment I, mucilage was visible 12 h after transplanting to the compact soil. The decapping and mucilage treatments affected neither the root elongation nor the root widening rates when the plants were grown in loose soil for 12 h. Root growth pressures of seminal axes in D, DM, I and IM treatments were 0.328, 0.288, 0.272 and 0.222 MPa, respectively, when the roots were grown in compact soil (1.5 Mg m(-3) density; 1.59 MPa penetrometer resistance). The contributions of mucilage and presence of the intact root cap without mucilage to the lubricating effect of root cap (percentage decrease in root penetration resistance caused by decapping) were 43 % and 58 %, respectively. The lubricating effect of the root cap was about 30 % and unaffected by the degree of soil compaction (for penetrometer resistances of 0.52, 1.20 and 1.59 MPa).

  5. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera)

    OpenAIRE

    Kumar Ramesh R.; Reddy Anjaneya Prasanna L.; Subbaiah Chinna J.; Kumar Niranjana A.; Prasad Nagendra H.N.; Bhukya Balakishan

    2011-01-01

    Ashwagandha (Withania somnifera) is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes) and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant) and crude fiber content exhibited strong association among them and ...

  6. Twelve tips for facilitating Millennials' learning.

    Science.gov (United States)

    Roberts, David H; Newman, Lori R; Schwartzstein, Richard M

    2012-01-01

    The current, so-called "Millennial" generation of learners is frequently characterized as having deep understanding of, and appreciation for, technology and social connectedness. This generation of learners has also been molded by a unique set of cultural influences that are essential for medical educators to consider in all aspects of their teaching, including curriculum design, student assessment, and interactions between faculty and learners.  The following tips outline an approach to facilitating learning of our current generation of medical trainees.  The method is based on the available literature and the authors' experiences with Millennial Learners in medical training.  The 12 tips provide detailed approaches and specific strategies for understanding and engaging Millennial Learners and enhancing their learning.  With an increased understanding of the characteristics of the current generation of medical trainees, faculty will be better able to facilitate learning and optimize interactions with Millennial Learners.

  7. Auxin increases the hydrogen peroxide (H2O2) concentration in tomato (Solanum lycopersicum) root tips while inhibiting root growth

    Czech Academy of Sciences Publication Activity Database

    Ivanchenko, M. G.; den Os, D.; Monshausen, G. B.; Dubrovsky, J, G.; Bednářová, Andrea; Krishnan, N.

    2013-01-01

    Roč. 112, č. 6 (2013), s. 1107-1116 ISSN 0305-7364 R&D Projects: GA ČR GAP501/10/1215 Grant - others:GA JU(CZ) 062/2011/P Institutional support: RVO:60077344 Keywords : auxin * ROS * hydrogen peroxide Subject RIV: EF - Botanics Impact factor: 3.295, year: 2013

  8. Soil incorporation of logging residue affects fine-root and mycorrhizal root-tip dynamics of young loblolly pine clones

    Science.gov (United States)

    Seth G. Pritchard; Chris A. Maier; Kurt H. Johnsen; Andrea J. Grabman; Anne P. Chalmers

    2010-01-01

    Loblolly pine (Pinus taeda L.) plantations cover a large geographic area of the southeastern USA and supply a large proportion of the nation’s wood products. Research on management strategies designed to maximize wood production while also optimizing nutrient use efficiency and soil C sequestration is needed. We used minirhizotrons to quantify the effects of...

  9. Tooth eruption without roots.

    Science.gov (United States)

    Wang, X-P

    2013-03-01

    Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the difficulties in studying late stages of tooth development and tooth movement and the lack of good model systems. Transgenic mice with eruption problems and short or no roots can be used as a powerful model for further deciphering of the cellular, molecular, and genetic mechanisms underlying root formation and tooth eruption. Better understanding of these processes can provide hints on delivering more efficient dental therapies in the future.

  10. Reconstruction of nasal tip and columella.

    Science.gov (United States)

    Faris, Callum; Vuyk, Hade D

    2011-02-01

    Reconstruction of nasal tip and columella defects is demanding area with a range of reconstructive options, varying in complexity depending on requirements from simple skin grafting to multiple stage reconstruction with regional flaps. A framework is suggested to aid the reader in choice of reconstruction by classifying the defect based on size and the requirements of one to three layer (full thickness) reconstruction. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Oracle Apex reporting tips and tricks

    CERN Document Server

    Bara, George

    2013-01-01

    Take advantage of all the exciting Reporting features of Oracle Application Express 4.2. Designed for a hands-on approach, this book contains in-depth practical guidelines from George Bara, a well-known Oracle Apex expert and blogger. From Classic to Interactive Reports, Web Services and Pdf Printing, "Oracle Apex Reporting Tips & Tricks" is a must-have for all database developers that want to make the most out of the Oracle Apex reporting engine.

  12. Exodontia: tips and techniques for better outcomes.

    Science.gov (United States)

    Dym, Harry; Weiss, Adam

    2012-01-01

    This article reviews and highlights exodontia tips as well as new techniques to make simple and complex exodontia more predictable and efficient with improved patient outcomes. A discussion of a powered periotome that has been developed to aid in the atraumatic extraction of teeth and another new device, the piezosurgery, increasingly used for outpatient oral surgery procedures are included. Physics forceps, a new type of exodontia forceps, is also discussed in this article. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Root Bending Is Antagonistically Affected by Hypoxia and ERF-Mediated Transcription via Auxin Signaling.

    Science.gov (United States)

    Eysholdt-Derzsó, Emese; Sauter, Margret

    2017-09-01

    When plants encounter soil water logging or flooding, roots are the first organs to be confronted with reduced gas diffusion resulting in limited oxygen supply. Since roots do not generate photosynthetic oxygen, they are rapidly faced with oxygen shortage rendering roots particularly prone to damage. While metabolic adaptations to low oxygen conditions, which ensure basic energy supply, have been well characterized, adaptation of root growth and development have received less attention. In this study, we show that hypoxic conditions cause the primary root to grow sidewise in a low oxygen environment, possibly to escape soil patches with reduced oxygen availability. This growth behavior is reversible in that gravitropic growth resumes when seedlings are returned to normoxic conditions. Hypoxic root bending is inhibited by the group VII ethylene response factor (ERFVII) RAP2.12, as rap2.12-1 seedlings show exaggerated primary root bending. Furthermore, overexpression of the ERFVII member HRE2 inhibits root bending, suggesting that primary root growth direction at hypoxic conditions is antagonistically regulated by hypoxia and hypoxia-activated ERFVIIs. Root bending is preceded by the establishment of an auxin gradient across the root tip as quantified with DII-VENUS and is synergistically enhanced by hypoxia and the auxin transport inhibitor naphthylphthalamic acid. The protein abundance of the auxin efflux carrier PIN2 is reduced at hypoxic conditions, a response that is suppressed by RAP2.12 overexpression, suggesting antagonistic control of auxin flux by hypoxia and ERFVII. Taken together, we show that hypoxia triggers an escape response of the primary root that is controlled by ERFVII activity and mediated by auxin signaling in the root tip. © 2017 American Society of Plant Biologists. All Rights Reserved.

  14. Uptake and Distribution of Aluminum in Root Apices of Two Rice Varieties under Aluminum Stress

    Directory of Open Access Journals (Sweden)

    MIFTAHUDIN

    2007-09-01

    Full Text Available Aluminum (Al toxicity is the major limiting factor of plant growth and production in acid soils. The target of Al toxicity is the root tip, which affects mainly on root growth inhibition. The aim of this research was to study the uptake and distribution of Al in root apices of two rice varieties IR64 (Al-sensitive and Krowal (Al-tolerant, which were grown on nutrient solution containing 0, 15, 30, 45, and 60 ppm of Al. The root growth was significantly inhibited in both rice varieties at as low as 15 ppm Al concentration. The adventive roots of both varieties showed stunted growth in respons to Al stress. There was no difference in root growth inhibition between both rice varieties as well as among Al concentrations. Al uptake on root apices was qualitatively and quantitatively analyzed. Histochemical staining of roots using hematoxylin showed dark purple color on 1 mm region of Al-treated root apices. Rice var. IR 64 tended to take up more Al in root tip than Krowal did. However, there was no statistically significant difference (p = 0.176 in root Al content of both varieties in response to different concentration and period of Al treatments. Al distribution in root apices was found in the epidermal and subepidermal region in both rice varieties. Based on those results, rice var. Krowal that was previously grouped as Al-tolerant variety has similar root growth and physiological response to Al stress as compared to Al-sensitive variety IR64.

  15. Uptake and localisation of lead in the root system of Brassica juncea

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Donald E.R. [University of the Sunshine Coast, Maroochydore DC, Qld 4558 (Australia)], E-mail: dmeyers@usc.edu.au; Auchterlonie, Graeme J. [Centre for Microscopy and Microanalysis, Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Brisbane, Qld 4067 (Australia)], E-mail: g.auchterlonie@uq.edu.au; Webb, Richard I. [Centre for Microscopy and Microanalysis, Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Brisbane, Qld 4067 (Australia)], E-mail: r.webb@uq.edu.au; Wood, Barry [Brisbane Surface Analysis Facility, Centre for Microscopy and Microanalysis, Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Brisbane, Qld 4067 (Australia)], E-mail: b.wood@uq.edu.au

    2008-05-15

    The uptake and distribution of Pb sequestered by hydroponically grown (14 days growth) Brassica juncea (3 days exposure; Pb activities 3.2, 32 and 217 {mu}M) was investigated. Lead uptake was restricted largely to root tissue. Examination using scanning transmission electron microscopy-energy dispersive spectroscopy revealed substantial and predominantly intracellular uptake at the root tip. Endocytosis of Pb at the plasma membrane was not observed. A membrane transport protein may therefore be involved. In contrast, endocytosis of Pb into a subset of vacuoles was observed, resulting in the formation of dense Pb aggregates. Sparse and predominantly extracellular uptake occurred at some distance from the root tip. X-ray photoelectron spectroscopy confirmed that the Pb concentration was greater in root tips. Heavy metal rhizofiltration using B. juncea might therefore be improved by breeding plants with profusely branching roots. Uptake enhancement using genetic engineering techniques would benefit from investigation of plasma membrane transport mechanisms. - The sites of Pb sequestration within the root system of hydroponically grown Brassica juncea were identified.

  16. Uptake and localisation of lead in the root system of Brassica juncea

    International Nuclear Information System (INIS)

    Meyers, Donald E.R.; Auchterlonie, Graeme J.; Webb, Richard I.; Wood, Barry

    2008-01-01

    The uptake and distribution of Pb sequestered by hydroponically grown (14 days growth) Brassica juncea (3 days exposure; Pb activities 3.2, 32 and 217 μM) was investigated. Lead uptake was restricted largely to root tissue. Examination using scanning transmission electron microscopy-energy dispersive spectroscopy revealed substantial and predominantly intracellular uptake at the root tip. Endocytosis of Pb at the plasma membrane was not observed. A membrane transport protein may therefore be involved. In contrast, endocytosis of Pb into a subset of vacuoles was observed, resulting in the formation of dense Pb aggregates. Sparse and predominantly extracellular uptake occurred at some distance from the root tip. X-ray photoelectron spectroscopy confirmed that the Pb concentration was greater in root tips. Heavy metal rhizofiltration using B. juncea might therefore be improved by breeding plants with profusely branching roots. Uptake enhancement using genetic engineering techniques would benefit from investigation of plasma membrane transport mechanisms. - The sites of Pb sequestration within the root system of hydroponically grown Brassica juncea were identified

  17. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  18. Integrated analysis of hydrothermal flow through pretreatment

    Directory of Open Access Journals (Sweden)

    Archambault-Leger Veronique

    2012-07-01

    Full Text Available Abstract Background The impact of hydrothermal flowthrough (FT pretreatment severity on pretreatment and solubilization performance metrics was evaluated for three milled feedstocks (corn stover, bagasse, and poplar and two conversion systems (simultaneous saccharification and fermentation using yeast and fungal cellulase, and fermentation by Clostridium thermocellum. Results Compared to batch pretreatment, FT pretreatment consistently resulted in higher XMG recovery, higher removal of non-carbohydrate carbon and higher glucan solubilization by simultaneous saccharification and fermentation (SSF. XMG recovery was above 90% for FT pretreatment below 4.1 severity but decreased at higher severities, particularly for bagasse. Removal of non-carbohydrate carbon during FT pretreatment increased from 65% at low severity to 80% at high severity for corn stover, and from 40% to 70% for bagasse and poplar. Solids obtained by FT pretreatment were amenable to high conversion for all of the feedstocks and conversion systems examined. The optimal time and temperature for FT pretreatment on poplar were found to be 16 min and 210°C. At these conditions, SSF glucan conversion was about 85%, 94% of the XMG was removed, and 62% of the non carbohydrate mass was solubilized. Solubilization of FT-pretreated poplar was compared for C. thermocellum fermentation (10% inoculum, and for yeast-fungal cellulase SSF (5% inoculum, cellulase loading of 5 and 10 FPU/g glucan supplemented with β-glucosidase at 15 and 30 U/g glucan. Under the conditions tested, which featured low solids concentration, C. thermocellum fermentation achieved faster rates and more complete conversion of FT-pretreated poplar than did SSF. Compared to SSF, solubilization by C. thermocellum was 30% higher after 4 days, and was over twice as fast on ball-milled FT-pretreated poplar. Conclusions XMG removal trends were similar between feedstocks whereas glucan conversion trends were significantly

  19. RUNTIME DICTIONARIES FOR ROOT

    CERN Document Server

    Wind, David Kofoed

    2013-01-01

    ROOT is the LHC physicists' common tool for data analysis; almost all data is stored using ROOT's I/O system. This system benefits from a custom description of types (a so-called dictionary) that is optimised for the I/O. Until now, the dictionary cannot be provided at run-time; it needs to be prepared in a separate prerequisite step. This project will move the generation of the dictionary to run-time, making use of ROOT 6's new just-in-time compiler. It allows a more dynamic and natural access to ROOT's I/O features especially for user code.

  20. Altered susceptibility to infection by Sinorhizobium meliloti and Nectria haematococca in alfalfa roots with altered cell cycle.

    Science.gov (United States)

    Woo, H-H; Hirsch, A M; Hawes, M C

    2004-07-01

    Most infections of plant roots are initiated in the region of elongation; the mechanism for this tissue-specific localization pattern is unknown. In alfalfa expressing PsUGT1 antisense mRNA under the control of the cauliflower mosaic virus (CaMV) 35S promoter, the cell cycle in roots is completed in 48 h instead of 24 h, and border cell number is decreased by more than 99%. These plants were found to exhibit increased root-tip infection by a fungal pathogen and reduced nodule formation by a bacterial symbiont. Thus, the frequency of infection in the region of elongation by Nectria haematocca was unaffected, but infection of the root tip was increased by more than 90%; early stages of Sinorhizobium meliloti infection and nodule morphology were normal, but the frequency of nodulation was fourfold lower than in wild-type roots.

  1. Tip loss correction for actuator / Navier Stokes computations

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming

    2004-01-01

    The new tip loss correction, initially developed for ID BEM computations [1], is now extended to 2D Actuator Disc / Navier-Stokes (AD/NS) computations and 3D Actuator Line / Navier-Stokes (AL/NS) computations. As shown in the paper, the tip loss correction is an important and necessary step...... for actuator / Navier-Stokes models. Comparisons of the present results with those obtained from a EM code with new tip correction and experimental data show that the tip loss correction is correctly implemented in the actuator / Navier-Stokes models. The results demonstrate also that difference between......, Actuator Line, Navier-Stokes equations, Tip loss correction....

  2. Selection of case studies describing PICC tip malposition.

    Science.gov (United States)

    Jackson, Andrew; Buttle, Andrew

    2016-07-28

    This article presents a number of case studies, spanning a 12-month period, associated with peripherally inserted central catheter (PICC) tip location. The aim is to generate debate around the journey PICC tips may take; it is not the purpose of this article to debate technological solutions to the issue of PICC tip location. The discussion of each case illustrates a wide range of potential aberrant PICC tip locations and offers an insight into how the abberant tip location was resolved in each case.

  3. Regulation of Arabidopsis root development by nitrate availability.

    Science.gov (United States)

    Zhang, H; Forde, B G

    2000-01-01

    When the root systems of many plant species are exposed to a localized source of nitrate (NO3- they respond by proliferating their lateral roots to colonize the nutrient-rich zone. This study reviews recent work with Arabidopsis thaliana in which molecular genetic approaches are being used to try to understand the physiological and genetic basis for this response. These studies have led to the conclusion that there are two distinct pathways by which NO3- modulates root branching in Arabidopsis. On the one hand, meristematic activity in lateral root tips is stimulated by direct contact with an enriched source of NO3- (the localized stimulatory effect). On the other, a critical stage in the development of the lateral root (just after its emergence from the primary root) is highly susceptible to inhibition by a systemic signal that is related to the amount of NO3- absorbed by the plant (the systemic inhibitory effect). Evidence has been obtained that the localized stimulatory effect is a direct effect of the NO3- ion itself rather than a nutritional effect. A NO3(-)-inducible MADS-box gene (ANR1) has been identified which encodes a component of the signal transduction pathway linking the external NO3- supply to the increased rate of lateral root elongation. Experiments using auxin-resistant mutants have provided evidence for an overlap between the auxin and NO3- response pathways in the control of lateral root elongation. The systemic inhibitory effect, which does not affect lateral root initiation but delays the activation of the lateral root meristem, appears to be positively correlated with the N status of the plant and is postulated to involve a phloem-mediated signal from the shoot.

  4. Abscisic acid and hypoxic induction of anoxia tolerance in roots of lettuce seedlings.

    Science.gov (United States)

    Kato-Noguchi, H

    2000-11-01

    Lettuce (Lactuca sativa L.) seedlings were subjected to anoxic stress after ABA-pretreatment (ABA-PT) or hypoxic-pretreatment (H-PT). The H-PT increased the survivability of the anoxia in roots of the seedlings by 5.2-fold compared to that of non-pretreated (N-PT) seedlings. ABA-PT also increased the survivability at concentrations greater than 1 microM, and the survivability increased with increasing ABA doses. At 100 microM ABA, the survivability was 4.5-fold greater than that of N-PT seedlings. During pretreatment periods, alcohol dehydrogenase (ADH, EC 1.1.1.1) activity in the roots became 3.1- and 3.4-fold greater than that of N-PT seedlings following 100 microM ABA-PT and H-PT seedlings, respectively. After the onset of anoxic stress, ADH activities in all roots increased, but the activities in H-PT and ABA-PT roots remained much greater than that in N-PT roots, and the average ethanol production rate for the initial 6 h was 5.3, 4.0 and 1.4 micromol g(-1) FW h(-1) for H-PT, ABA-PT and N-PT roots, respectively. Roots of the seedlings lost ATP rapidly under anoxic stress; however, the decrease in ATP was much slower in the ABA-PT and H-PT seedlings than in the N-PT seedlings. These results suggest that the ABA-PT and H-PT may maintain ATP levels due to activation of ethanolic fermentation, which may be one of the causes of the increasing anoxia tolerance in the seedling roots. Measurement of endogenous ABA levels, however, showed that ABA levels did not increase during the H-PT, suggesting that the H-PT does not increase tolerance through an increase in ABA levels.

  5. Evaluation of a Sonic Device Designed to Activate Irrigant in the Root Canal

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, Bram; Versluis, Michel; van der Sluis, Lucas W. M.

    Introduction: The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the

  6. Evaluation of a sonic device designed to activate irrigant in the root canal

    NARCIS (Netherlands)

    Jiang, L.M.; Verhaagen, B.; Versluis, M.; van der Sluis, L.W.M.

    2010-01-01

    Introduction The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the

  7. Evaluation of a Sonic Device Designed to Activate Irrigant in the Root Canal

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Verhaagen, B.; Versluis, Michel; van der Sluis, Lucas W.M.

    2010-01-01

    Introduction The aims of this study were to evaluate the removal of dentin debris from the root canal by sonic or ultrasonic activation of the irrigant and the physical mechanisms of sonic activation by visualizing the oscillations of the sonic tip, both inside and outside the confinement of the

  8. Biocontrol of tomato foot and root rot by Pseudomonas bacteria in stonewool

    NARCIS (Netherlands)

    Validov, Shamil

    2007-01-01

    The research described in this thesis shows that the enrichment technique based on competitive root tip colonization allows the isolation of bacteria which can protect plants from TFRR through the mechanism competition for nutrients (and niches). The efficacy of biocontrol of one of these strains,

  9. Abnormal mitosis in root meristem cells of Allium cepa L. induced by ...

    African Journals Online (AJOL)

    This investigation was aimed to find mitotic abnormalities as cytological evidence induced by the dye in root tip cells of onion (Allium cepa L.) grown in different concentrations: 0.01, 0.05, 0.1, 0.5 and 1.0% (weight per volume) prepared in distilled water in separate treatment schedules for 24 and 48 h. Mitotic aberrations ...

  10. Soil Penetration by Earthworms and Plant Roots--Mechanical Energetics of Bioturbation of Compacted Soils.

    Directory of Open Access Journals (Sweden)

    Siul Ruiz

    Full Text Available We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip. The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities.

  11. Soil Penetration by Earthworms and Plant Roots--Mechanical Energetics of Bioturbation of Compacted Soils.

    Science.gov (United States)

    Ruiz, Siul; Or, Dani; Schymanski, Stanislaus J

    2015-01-01

    We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip). The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities.

  12. Understanding Ionic Liquid Pretreatment of Lignocellulosic Biomasses

    Science.gov (United States)

    Pretreatment of biomass is essential for breaking apart highly ordered and crystalline plant cell walls and loosening the lignin and hemicellulose conjugation to cellulose microfibrills, thereby facilitating enzyme accessibility and adsorption and reducing costs of downstream saccharification proces...

  13. Extrusion Pretreatment of Lignocellulosic Biomass: A Review

    Directory of Open Access Journals (Sweden)

    Jun Zheng

    2014-10-01

    Full Text Available Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs.

  14. Hydrolysis of alkaline pretreated banana peel

    Science.gov (United States)

    Fatmawati, A.; Gunawan, K. Y.; Hadiwijaya, F. A.

    2017-11-01

    Banana peel is one of food wastes that are rich in carbohydrate. This shows its potential as fermentation substrate including bio-ethanol. This paper presented banana peel alkaline pretreatment and enzymatic hydrolysis. The pretreatment was intended to prepare banana peel in order to increase hydrolysis performance. The alkaline pretreatment used 10, 20, and 30% w/v NaOH solution and was done at 60, 70 and 80°C for 1 hour. The hydrolysis reaction was conducted using two commercial cellulose enzymes. The reaction time was varied for 3, 5, and 7 days. The best condition for pretreatment process was one conducted using 30% NaOH solution and at 80°C. This condition resulted in cellulose content of 90.27% and acid insoluble lignin content of 2.88%. Seven-day hydrolysis time had exhibited the highest reducing sugar concentration, which was7.2869 g/L.

  15. Root morphological responses of three hot pepper cultivars to Cd exposure and their correlations with Cd accumulation.

    Science.gov (United States)

    Huang, Baifei; Xin, Junliang; Dai, Hongwen; Liu, Aiqun; Zhou, Wenjing; Yi, Yumei; Liao, Kebing

    2015-01-01

    Cultivars of hot pepper (Capsicum annuum L.) differ widely in their fruit cadmium (Cd) concentrations. Previously, we suggested that low-Cd cultivars are better able to prevent the translocation of Cd from roots to aboveground parts, but the corresponding mechanisms are still unknown. In this study, we aimed to improve understanding of the root morphological characteristics of the mechanisms involved in two low-Cd and a high-Cd cultivar. Seedlings were grown in nutrient solutions containing 0 (control), 2, and 10 μM Cd for 20 days, and Cd contents for the three cultivars were compared with changes in root morphology. The total root length (RL), root surface area (SA), number of root tips (RT), and specific root length (SRL) of all cultivars were decreased significantly by the 10 μM Cd treatment with the exception of the SA in JFZ, which showed no obvious change. For each cultivar, the 10 μM Cd treatment decreased significantly RL and SA specifically in roots with diameters (RD) of RD ≤ 0.2 mm or 0.2 mm roots with diameters of 0.6 mm root morphology. In the 10 μM Cd treatment, root volume (RV), SA, and RT of all cultivars were negatively correlated with Cd concentration and amount in roots. However, RL, SA, RV, and RT of all cultivars were positively correlated with Cd concentration and amount in shoots, and translocation rate of Cd. The two low-Cd cultivars of hot pepper had less root tips, shorter root length, and smaller root surface area than the high-Cd cultivar in 10 μM Cd treatment, which may play a vital role in reducing root-to-shoot Cd translocation.

  16. The role of actin in root hair morphogenesis : studies with lipochito-oligosaccharide as a growth stimulator and cytochalasin as an actin perturbing drug

    NARCIS (Netherlands)

    Miller, D.D.; Ruijter, de N.C.A.; Bisseling, T.; Emons, A.M.C.

    1999-01-01

    Root hairs develop from bulges on root epidermal cells and elongate by tip growth, in which Golgi vesicles are targeted, released and inserted into the plasma membrane on one side of the cell. We studied the role of actin in vesicle delivery and retention by comparing the actin filament

  17. Treatment of young spruce shoots with SO2 and H2S : Effects on fine root chromosomes in relation to changes in the thiol content and redox state

    NARCIS (Netherlands)

    Wonisch, A; Tausz, M; Muller, M; Weidner, W; De Kok, LJ; Grill, D

    1999-01-01

    Three year old spruce trees (Picea omorika) were exposed to 100 and 225 nl l(-1) SO2 and H2S for three weeks. The number of chromosomal aberrations and the mitotic index in the root tip meristems, and glutathione and cysteine contents in fine roots were determined twice weekly. An increase in

  18. Ultrasonic sludge pretreatment under pressure.

    Science.gov (United States)

    Le, Ngoc Tuan; Julcour-Lebigue, Carine; Delmas, Henri

    2013-09-01

    The objective of this work was to optimize the ultrasound (US) pretreatment of sludge. Three types of sewage sludge were examined: mixed, secondary and secondary after partial methanisation ("digested" sludge). Thereby, several main process parameters were varied separately or simultaneously: stirrer speed, total solid content of sludge (TS), thermal operating conditions (adiabatic vs. isothermal), ultrasonic power input (PUS), specific energy input (ES), and for the first time external pressure. This parametric study was mainly performed for the mixed sludge. Five different TS concentrations of sludge (12-36 g/L) were tested for different values of ES (7000-75,000 kJ/kgTS) and 28 g/L was found as the optimum value according to the solubilized chemical oxygen demand in the liquid phase (SCOD). PUS of 75-150 W was investigated under controlled temperature and the "high power input - short duration" procedure was the most effective at a given ES. The temperature increase in adiabatic US application significantly improved SCOD compared to isothermal conditions. With PUS of 150 W, the effect of external pressure was investigated in the range of 1-16 bar under isothermal and adiabatic conditions for two types of sludge: an optimum pressure of about 2 bar was found regardless of temperature conditions and ES values. Under isothermal conditions, the resulting improvement of sludge disintegration efficacy as compared to atmospheric pressure was by 22-67% and 26-37% for mixed and secondary sludge, respectively. Besides, mean particle diameter (D[4,3]) of the three sludge types decreased respectively from 408, 117, and 110 μm to about 94-97, 37-42, and 36-40 μm regardless of sonication conditions, and the size reduction process was much faster than COD extraction. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Pretreatment techniques for biofuels and biorefineries

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhen (ed.) [Chinese Academy of Sciences, Kunming, YN (China). Xishuangbanna Tropical Botonical Garden

    2013-02-01

    The first book focused on pretreatment techniques for biofuels contributed by the world's leading experts. Extensively covers the different types of biomass, various pretreatment approaches and methods that show the subsequent production of biofuels and chemicals. In addition to traditional pretreatment methods, novel techniques are also introduced and discussed. An accessible reference work for students, researchers, academicians and industrialists in biorefineries. This book includes 19 chapters contributed by the world's leading experts on pretreatment methods for biomass. It extensively covers the different types of biomass (e.g. molasses, sugar beet pulp, cheese whey, sugarcane residues, palm waste, vegetable oil, straws, stalks and wood), various pretreatment approaches (e.g. physical, thermal, chemical, physicochemical and biological) and methods that show the subsequent production of biofuels and chemicals such as sugars, ethanol, extracellular polysaccharides, biodiesel, gas and oil. In addition to traditional methods such as steam, hot-water, hydrothermal, diluted-acid, organosolv, ozonolysis, sulfite, milling, fungal and bacterial, microwave, ultrasonic, plasma, torrefaction, pelletization, gasification (including biogas) and liquefaction pretreatments, it also introduces and discusses novel techniques such as nano and solid catalysts, organic electrolyte solutions and ionic liquids. This book offers a review of state-of-the-art research and provides guidance for the future paths of developing pretreatment techniques of biomass for biofuels, especially in the fields of biotechnology, microbiology, chemistry, materials science and engineering. It intends to provide a systematic introduction of pretreatment techniques. It is an accessible reference work for students, researchers, academicians and industrialists in biorefineries.

  20. The roots of nodulins.

    NARCIS (Netherlands)

    Nap, J.P.H.; Bisseling, T.

    1990-01-01

    Nodulin gene expression is an integral and highly specific part of the formation of nitrogenfixing nodules on the roots of leguminous plants. Dependent on the time of expression during root nodule development, nodulin genes can be divided into early and late nodulin genes. A brief overview of the

  1. Irrational Square Roots

    Science.gov (United States)

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  2. An experimental study on suppressing Tip Vortex Cavitation by means of a Flexible Thread

    Science.gov (United States)

    Seo, Jeonghwa; Amini, Ali; Lee, Seung Jae; Park, Jongyeol; Yeo, Honggu; Farhat, Mohamed; Rhee, Shin Hyung

    2017-11-01

    Tip vortex cavitation (TVC) is an important issue in hydraulic machines and efforts to reduce it are required. The present study aims to mitigate the intensity of a TVC by attaching a flexible thread at the hydrofoil tip. As the test model, a hydrofoil with elliptical planform with NACA 16-020 cross section was used. Reynolds number, incidence angle, and cavitation number were varied to examine the cavitation suppression effects under different flow conditions. It is observed that the size of the cavitating core of the tip vortex is drastically reduced in comparison to the same flow conditions without the thread. The vortex roll-up and formation was disturbed by the fluctuations of the flexible string around the TVC, resulting in cavitation intensity reduction. In addition, the thread diameter and length were varied, to show that the technique was proved effective even for strings as short as half of the root chord length, which acted like a stiff thread. Our results demonstrate that there exists a critical thread length of, where the decrease in the cavitating core diameter converges. It is also found that this recipe ameliorates the desinent cavitation index of the TVC.

  3. The role of root development of Avena fatua in conferring soil strength.

    Science.gov (United States)

    Dumlao, Matthew R; Ramananarivo, Sophie; Goyal, Vivek; DeJong, Jason T; Waller, Jack; Silk, Wendy K

    2015-07-01

    Roots play an important role in strengthening and stabilizing soils. Existing models predict that tensile strength and root abundance are primary factors that strengthen soil. This study quantified how both factors are affected by root developmental stage.• Focusing on early development of Avena fatua, a common grassland species with a fibrous root system, we chose three developmental stages associated with major changes in the root system. Seeds were planted in rhizotrons for easy viewing and pots to allow root growth surrounded by soil. Tensile strength was determined by subjecting root segments to a progressively larger pulling force until breaking occurred. Root abundance at two depths was characterized by the cross-sectional area of the roots divided by the area of the soil core (i.e., root area ratio). Shear strength of 50 mm saturated soil columns was determined with a modified interface direct shear device.• Tensile strength increased by a factor of ≥15× with distance from the root tip. Thus, soil-strengthening properties increased with root cell development. Plants grown under dry soil conditions produced roots with higher maximal tensile strength (41.9 MPa vs. approximately 17 MPa), largely explained by 33% thinner diameters. Over 7 weeks of root growth, root abundance increased by a factor of 4.8× while saturated soil shear strength increased by 24% in the upper soil layer.• Root development should be incorporated into models of soil stability to improve understanding of this important environmental property. © 2015 Botanical Society of America, Inc.

  4. Relocalization of human chromatin remodeling cofactor TIP48 in mitosis

    International Nuclear Information System (INIS)

    Sigala, Barbara; Edwards, Mina; Puri, Teena; Tsaneva, Irina R.

    2005-01-01

    TIP48 is a highly conserved eukaryotic AAA + protein which is an essential cofactor for several complexes involved in chromatin acetylation and remodeling, transcriptional and developmental regulation and nucleolar organization and trafficking. We show that TIP48 abundance in HeLa cells did not change during the cell cycle, nor did its distribution in various biochemical fractions. However, we observed distinct changes in the subcellular localization of TIP48 during M phase using immunofluorescence microscopy. Our studies demonstrate that in interphase cells TIP48 was found mainly in the nucleus and exhibited a distinct localization in the nuclear periphery. As the cells entered mitosis, TIP48 was excluded from the condensing chromosomes but showed association with the mitotic apparatus. During anaphase, some TIP48 was detected in the centrosome colocalizing with tubulin but the strongest staining appeared in the mitotic equator associated with the midzone central spindle. Accumulation of TIP48 in the midzone and the midbody was observed in late telophase and cytokinesis. This redeployment of TIP48 during anaphase and cytokinesis was independent of microtubule assembly. The relocation of endogenous TIP48 to the midzone/midbody under physiological conditions suggests a novel and distinct function for TIP48 in mitosis and possible involvement in the exit of mitosis

  5. Numerical Simulation of LVAD Inflow Cannulas with Different Tip

    Directory of Open Access Journals (Sweden)

    Guang-Mao Liu

    2012-01-01

    Full Text Available The tip structure of LVAD inflow cannula is one of major factors to lead adverse events such as thrombosis and suction leading to obstruction. In this research, four kinds of tips that had been used in inflow cannulas were selected and designed. The flow field of the four inflow cannulas inserted into the apex of left ventricle (LV was numerically computed by computational fluid dynamics. The flow behavior was analyzed in order to compare the blood compatibility and suction in left ventricle and cannulas after the inflow cannulas with different tips were inserted to the apex of LV. The results showed that the cannula tip structure affected the LVAD performance. Among these four cannulas, the trumpet-tipped inflow cannula owned the best performance in smooth flow velocity distribution without backflow or low-velocity flow so that it was the best in blood compatibility. Nevertheless, the caged tipped cannula was the worst in blood compatibility. And the blunt-tipped and beveled tipped inflow cannulas may obstruct more easily than trumpet and caged tipped inflow cannulas because of their shape. The study indicated that the trumpet tip was the most preferable for the inflow cannula of long-term LVAD.

  6. [Plastic micro-tips for drug delivery].

    Science.gov (United States)

    Muslija, A; Guber, A E; Heckele, M; Herrmann, D; Pfleging, W; Schaller, Th

    2002-01-01

    Removal or exact transfer of minimum substance volumes from reservoirs or microfluidic systems may be accomplished by means of miniaturized tips with integrated through-going capillaries. Applications in biomedical engineering, e.g. for the application of drugs, or in life sciences, e.g. equipping of microarrays, require the use of disposable plastic products for hygienic reasons and reasons of costs. For this purpose, a method to fabricate microtips out of plastic by doublesided molding has been developed at the Forschungszentrum Karlsruhe.

  7. Semi-empirical crack tip analysis

    Science.gov (United States)

    Chudnovsky, A.; Ben Ouezdon, M.

    1988-01-01

    Experimentally observed crack opening displacements are employed as the solution of the multiple crack interaction problem. Then the near and far fields are reconstructed analytically by means of the double layer potential technqiue. Evaluation of the effective stress intensity factor resulting from the interaction of the main crack and its surrounding crazes in addition to the remotely applied load is presented as an illustrative example. It is shown that crazing (as well as microcracking) may constitute an alternative mechanism to Dugdale-Berenblatt models responsible for the cancellation of the singularity at the crack tip.

  8. Dynamic QTL and epistasis analysis on seedling root traits in upland cotton.

    Science.gov (United States)

    Liang, Qingzhi; Li, Pengbo; Hu, Cheng; Hua, Hua; Li, Zhaohu; Rong, Yihua; Wang, Kunbo; Hua, Jinping

    2014-04-01

    Roots are involved in acquisition of water and nutrients, as well as in providing structural support to plant. The root system provides a dynamic model for developmental analysis. Here, we investigated quantitative trait loci (QTL), dynamic conditional QTL and epistatic interactions for seedling root traits using an upland cotton F2 population and a constructed genetic map. Totally, 37 QTLs for root traits, 35 dynamic conditional QTLs based on the net increased amount of root traits (root tips, forks, length, surface area and volume) (i) after transplanting 10 days compared to 5 days, and (ii) after transplanting 15 days to 10 days were detected. Obvious dynamic characteristic of QTL and dynamic conditional QTL existed at different developmental stages of root because QTL and dynamic conditional QTL had not been detected simultaneously. We further confirmed that additive and dominance effects of QTL qRSA-chr1-1 in interval time 5 to 10 DAT (days after transplant) offset the effects in 10 to 15 DAT. Lots of two-locus interactions for root traits were identified unconditionally or dynamically, and a few epistatic interactions were only detected simultaneously in interval time of 5-10 DAT and 10-15 DAT, suggesting different interactive genetic mechanisms on root development at different stages. Dynamic conditional QTL and epistasis effects provide new attempts to understand the dynamics of roots and provide clues for root architecture selection in upland cotton.

  9. Basipetal auxin transport is required for gravitropism in roots of Arabidopsis

    Science.gov (United States)

    Rashotte, A. M.; Brady, S. R.; Reed, R. C.; Ante, S. J.; Muday, G. K.; Davies, E. (Principal Investigator)

    2000-01-01

    Auxin transport has been reported to occur in two distinct polarities, acropetally and basipetally, in two different root tissues. The goals of this study were to determine whether both polarities of indole-3-acetic acid (IAA) transport occur in roots of Arabidopsis and to determine which polarity controls the gravity response. Global application of the auxin transport inhibitor naphthylphthalamic acid (NPA) to roots blocked the gravity response, root waving, and root elongation. Immediately after the application of NPA, the root gravity response was completely blocked, as measured by an automated video digitizer. Basipetal [(3)H]IAA transport in Arabidopsis roots was inhibited by NPA, whereas the movement of [(14)C]benzoic acid was not affected. Inhibition of basipetal IAA transport by local application of NPA blocked the gravity response. Inhibition of acropetal IAA transport by application of NPA at the root-shoot junction only partially reduced the gravity response at high NPA concentrations. Excised root tips, which do not receive auxin from the shoot, exhibited a normal response to gravity. The Arabidopsis mutant eir1, which has agravitropic roots, exhibited reduced basipetal IAA transport but wild-type levels of acropetal IAA transport. These results support the hypothesis that basipetally transported IAA controls root gravitropism in Arabidopsis.

  10. The rapid inhibition of root respiration after exposure of bean ( Phaseolus vulgaris L.) plants to ozone

    Science.gov (United States)

    Hofstra, G.; Ali, A.; Wukasch, R. T.; Fletcher, R. A.

    The metabolic activity of the roots was very sensitive to the changes induced in the leaves by O 3. Respiratory activity began to decrease well before visible injury appeared on the leaves, and the per cent reduction of respiration was much greater than the per cent leaf injury. The triphenyl tetrazolium chloride (TTC) staining technique revealed changes in root tips very quickly, was generally more sensitive to changes in respiratory activity and was a convenient technique for handling large numbers of samples. Reducing foliar injury from O 3 with low levels of SO 2 reduced the effects on the roots indicating the effect of O 3 is on processes in the leaf.

  11. Quantifying the impact of soil compaction on root system architecture in tomato (Solanum lycopersicum) by X-ray micro-computed tomography.

    Science.gov (United States)

    Tracy, Saoirse R; Black, Colin R; Roberts, Jeremy A; Sturrock, Craig; Mairhofer, Stefan; Craigon, Jim; Mooney, Sacha J

    2012-07-01

    We sought to explore the interactions between roots and soil without disturbance and in four dimensions (i.e. 3-D plus time) using X-ray micro-computed tomography. The roots of tomato Solanum lycopersicum 'Ailsa Craig' plants were visualized in undisturbed soil columns for 10 consecutive days to measure the effect of soil compaction on selected root traits including elongation rate. Treatments included bulk density (1.2 vs. 1.6 g cm(-3)) and soil type (loamy sand vs. clay loam). Plants grown at the higher soil bulk density exploited smaller soil volumes (P < 0.05) and exhibited reductions in root surface area (P < 0.001), total root volume (P < 0.001) and total root length (P < 0.05), but had a greater mean root diameter (P < 0.05) than at low soil bulk density. Swelling of the root tip area was observed in compacted soil (P < 0.05) and the tortuosity of the root path was also greater (P < 0.01). Root elongation rates varied greatly during the 10-d observation period (P < 0.001), increasing to a maximum at day 2 before decreasing to a minimum at day 4. The emergence of lateral roots occurred later in plants grown in compacted soil (P < 0.01). Novel rooting characteristics (convex hull volume, centroid and maximum width), measured by image analysis, were successfully employed to discriminate treatment effects. The root systems of plants grown in compacted soil had smaller convex hull volumes (P < 0.05), a higher centre of mass (P < 0.05) and a smaller maximum width than roots grown in uncompacted soil. Soil compaction adversely affects root system architecture, influencing resource capture by limiting the volume of soil explored. Lateral roots formed later in plants grown in compacted soil and total root length and surface area were reduced. Root diameter was increased and swelling of the root tip occurred in compacted soil.

  12. Alternative techniques in root canal debridement

    Science.gov (United States)

    Luca, Ruxandra; Todea, Carmen; Bǎlǎbuc, Cosmin; Nica, Luminita; Armani, Giacomo; Locovei, Cosmin

    2014-01-01

    Studies have demonstrated that conventional chemo-mechanical preparation is limited regarding the decontamination of the endodontic space, which is why alternative techniques such as laser radiation have their importance in the modern endodontic treatment. The present study aims to assess the possibility of improving the debridement of the root canals by removing smear layer using Er: YAG laser radiation. We used 18 extracted teeth, which were subjected to the same initial protocol and then divided into 5 study groups: the control group has not been treated with laser; the other 4 groups were exposed to laser radiation using two different geometries peaks of quartz and two energy levels. Scanning electronic microscopy revealed an increased efficiency in the debridement of all interested areas when using PIPS and XPulse tips at proper energy. In the two groups treated with inferior laser energy, the debridement didn't prove to be superior to the conventional treatment.

  13. Root development and structure in seedlings of Ginkgo biloba.

    Science.gov (United States)

    Bonacorsi, Nikole K; Seago, James L

    2016-02-01

    The popular, highly recognizable, well-known gymnosperm, Ginkgo biloba, was studied to document selected developmental features, which are little known in its primary root system from root tips to cotyledonary node following seed germination. Using seedlings grown in soil, vermiculite, or a mixture, we examined sections at various distances from the root cap to capture a developmental sequence of anatomical structures by using standard brightfield, epifluorescence, and confocal microscopic techniques. The vascular cylinder is usually a diarch stele, although modified diarchy and triarchy are found. Between exarch protoxylem poles, metaxylem usually develops into a complete disc, except near the transition region, which has irregularly arranged tracheary cells. The disc of primary xylem undergoes secondary growth on its metaxylem flanks with many tracheids added radially within a few weeks. Production of fibers in secondary phloem also accompanies secondary growth. In the cortex, endodermis produces Casparian bands early in development and continues into the upper transition region. Phi cells with phi-thickenings (bands of lignified walls) of a layer of inner cortex are often evident before endodermis, and then adjoining, additional layers of cortex develop phi cells; phi cells do not occur in the upper transition region or stem. An exodermis is produced early in root development and is continuous into the transition region and cotyledonary node. Seedling root axes of Ginkgo biloba are more complex than the literature suggests, and our findings contribute to our knowledge of root structure of this ancient gymnosperm. © 2016 Botanical Society of America.

  14. Root canal preparation with Er:YSGG laser

    Science.gov (United States)

    Benthin, Hartmut; Ertl, Thomas P.; Onal, B.; Schruender, Stephan; Mueller, Gerhard J.

    1994-12-01

    The high level of efficiency of hard tissue ablation with Er:YAG and Er:YSGG lasers is well known. Of these lasers it is possible only to transmit Er:YSGG laser radiation with OH reduced quartz fibers. Most of the fibers we use in this study were prepared as hemispherical fiber tips. Fifty single rooted teeth were divided into ten groups (n equals 5). After conventional opening of the pulp chamber, root canal preparation was performed in five groups under water only using the laser. In the other five groups preparation with K-files to size 35 was performed before treatment with laser radiation. All teeth were axially separated with direct access to the root canal and examined in SEM investigations. The groups were compared by measuring the areas with patent dentin tubules. Representative areas were examined by TEM. The temperature at the root surface was measured during laser irradiation with thermocouples positioned at several points. The in-vitro study of the effect of the high delivered energy (50 - 100 mJ per pulse) in the root canal showed a good ablation effect. Most of the dentin tubules were opened. The increase in temperature at the root surface was tolerable.

  15. Assays for root hydrotropism and response to water stress.

    Science.gov (United States)

    Eapen, Delfeena; Martínez, Jesús J; Cassab, Gladys I

    2015-01-01

    Roots of most terrestrial plants show hydrotropic curvature when exposed to a moisture gradient. Though this root response is difficult to visualize in the soil habitat, there are reports of hydrotropism as an inherent response of primary roots of different plant species, such as Arabidopsis thaliana, Pisum sativum, and Zea mays L., from in vitro system studies. Many plant species use hydrotropism as a mechanism of avoidance to water stress. The actively growing root tip has the ability to change its direction towards greater water availability by differential growth in the elongation zone. The study of this tropic response has been challenged by the interaction of gravitropism, thigmotropism and possibly phototropism. It is hard to visualize hydrotropic curvature in vitro unless all other stimuli are neutralized by the presence of a moisture gradient. In this chapter, we describe methods for preparation of two assay systems used to visualize hydrotropic curvature in the primary roots of Arabidopsis and one moisture gradient system used for maize root seedlings.

  16. Mutagenic Potentials of the Sterilizing Fluid – Puritil on Root Tip ...

    African Journals Online (AJOL)

    The sterilizing fluid was found to exhibit both mitoclassic and chromatoclassic effects and thus induced a number of abnormalities. These abnormalities included disturbed interphase involving nuclear lesions and nuclear dissolutions, micronuclei and binucleate cells, sticky metaphase, disturbed anaphase involving ...

  17. Cytogenotoxicity of SPL "(Spent Pot Liner)" by plant root tip bioassays

    OpenAIRE

    Andrade, Larissa Fonseca

    2014-01-01

    O SPL (Spent Pot Liner) é um resíduo sólido, tóxico, gerado nas indústrias de alumínio, durante o processo de eletrólise da alumina. Sua composição é bastante variável, incluindo sais de fluoreto, cianetos, metais e compostos orgânicos. No Brasil, mais de 35.000 t de SPL são geradas por ano. Algumas indústrias já adotaram o co-processamento do produto, que é utilizado como matéria prima nas indústrias cimenteiras. No entanto, os efeitos do SPL sobre os sistemas biológicos necessitam ser compr...

  18. The actin cytoskeleton in root hairs: all is fine at the tip

    NARCIS (Netherlands)

    Ketelaar, T.

    2013-01-01

    Filamentous actin forms characteristic bundles in plant cells that facilitate cytoplasmic streaming. In contrast, networks of actin exhibiting fast turnover are found especially near sites of rapid cell expansion. These networks may serve various functions including delivering and retaining vesicles

  19. Preparation of HMW DNA from plant nuclei and chromosomes isolated from root tips

    Czech Academy of Sciences Publication Activity Database

    Šimková, Hana; Čihalíková, Jarmila; Vrána, Jan; Lysák, Martin; Doležel, Jaroslav

    2003-01-01

    Roč. 46, č. 3 (2003), s. 369-373 ISSN 0006-3134 R&D Projects: GA AV ČR IAA6038204 Institutional research plan: CEZ:AV0Z5038910 Keywords : banan * flow cytometry * nuclear DNA content Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.919, year: 2003

  20. Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity.

    Science.gov (United States)

    Michael P. Amaranthus; Debbie Page-Dumroese; Al Harvey; Efren Cazares; Larry F. Bednar

    1996-01-01

    Three levels of organic matter removal (bole only; bole and crowns; and bole, crowns, and forest floor) and three levels of mechanical soil compaction (no compaction, moderate compaction, and severe soil compaction) were studied as they influence Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and western white...

  1. Water movement through plant roots – exact solutions of the water flow equation in roots with linear or exponential piecewise hydraulic properties

    Directory of Open Access Journals (Sweden)

    F. Meunier

    2017-12-01

    Full Text Available In 1978, Landsberg and Fowkes presented a solution of the water flow equation inside a root with uniform hydraulic properties. These properties are root radial conductivity and axial conductance, which control, respectively, the radial water flow between the root surface and xylem and the axial flow within the xylem. From the solution for the xylem water potential, functions that describe the radial and axial flow along the root axis were derived. These solutions can also be used to derive root macroscopic parameters that are potential input parameters of hydrological and crop models. In this paper, novel analytical solutions of the water flow equation are developed for roots whose hydraulic properties vary along their axis, which is the case for most plants. We derived solutions for single roots with linear or exponential variations of hydraulic properties with distance to root tip. These solutions were subsequently combined to construct single roots with complex hydraulic property profiles. The analytical solutions allow one to verify numerical solutions and to get a generalization of the hydric behaviour with the main influencing parameters of the solutions. The resulting flow distributions in heterogeneous roots differed from those in uniform roots and simulations led to more regular, less abrupt variations of xylem suction or radial flux along root axes. The model could successfully be applied to maize effective root conductance measurements to derive radial and axial hydraulic properties. We also show that very contrasted root water uptake patterns arise when using either uniform or heterogeneous root hydraulic properties in a soil–root model. The optimal root radius that maximizes water uptake under a carbon cost constraint was also studied. The optimal radius was shown to be highly dependent on the root hydraulic properties and close to observed properties in maize roots. We finally used the obtained functions for evaluating the impact

  2. Water movement through plant roots - exact solutions of the water flow equation in roots with linear or exponential piecewise hydraulic properties

    Science.gov (United States)

    Meunier, Félicien; Couvreur, Valentin; Draye, Xavier; Zarebanadkouki, Mohsen; Vanderborght, Jan; Javaux, Mathieu

    2017-12-01

    In 1978, Landsberg and Fowkes presented a solution of the water flow equation inside a root with uniform hydraulic properties. These properties are root radial conductivity and axial conductance, which control, respectively, the radial water flow between the root surface and xylem and the axial flow within the xylem. From the solution for the xylem water potential, functions that describe the radial and axial flow along the root axis were derived. These solutions can also be used to derive root macroscopic parameters that are potential input parameters of hydrological and crop models. In this paper, novel analytical solutions of the water flow equation are developed for roots whose hydraulic properties vary along their axis, which is the case for most plants. We derived solutions for single roots with linear or exponential variations of hydraulic properties with distance to root tip. These solutions were subsequently combined to construct single roots with complex hydraulic property profiles. The analytical solutions allow one to verify numerical solutions and to get a generalization of the hydric behaviour with the main influencing parameters of the solutions. The resulting flow distributions in heterogeneous roots differed from those in uniform roots and simulations led to more regular, less abrupt variations of xylem suction or radial flux along root axes. The model could successfully be applied to maize effective root conductance measurements to derive radial and axial hydraulic properties. We also show that very contrasted root water uptake patterns arise when using either uniform or heterogeneous root hydraulic properties in a soil-root model. The optimal root radius that maximizes water uptake under a carbon cost constraint was also studied. The optimal radius was shown to be highly dependent on the root hydraulic properties and close to observed properties in maize roots. We finally used the obtained functions for evaluating the impact of root maturation

  3. Root resorption following periodontally accelerated osteogenic orthodontics

    Directory of Open Access Journals (Sweden)

    Donald J Ferguson

    2016-01-01

    Full Text Available Background: Literature evidence suggests that root resorption, an adverse side effect of orthodontic therapy, may be decreased under conditions of alveolar osteopenia, a condition characterized by diminished bone density and created secondary to alveolar corticotomy (Cort surgery. Purpose: To compare root resorption of the maxillary central incisors following nonextraction orthodontic therapy with and without Cort surgery. Materials and Methods: The sample comprised two groups, with and without Cort and was matched by age and gender: Cort-facilitated nonextraction orthodontics with 27 subjects, 53 central incisors of mean age 24.8 ± 10.2 years, and conventional (Conv nonextraction orthodontics with 27 subjects, 54 incisors with mean age of 19.6 ± 8.8 years. All periapical radiographs were taken with the paralleling technique; total tooth lengths of the right and left central incisors were measured by projecting and enlarging the periapical radiographs exactly 8 times. Results: t-tests revealed a significant decrease in treatment time in the Cort group (6.3 ± 8.0 vs. 17.4 ± 20.2 months, P = 0.000. Pretreatment root lengths were not significantly different (P = 0.11, but Conv had significantly shorter roots at posttreatment when compared with Cort (P = 0.03. Significant root resorption (P < 0.01 occurred in both Cort (0.3 mm and Conv (0.7 mm, but the increment of change was significantly greater in Conv (P < 0.03. The variable SNA increased significantly in the Cort (P = 0.001 group and decreased significantly in the Conv group (P < 0.001. Conclusions: Based on the conditions of this study, it may be concluded that Cort-facilitated nonextraction orthodontic therapy results in less root resorption and enhanced alveolar support within a significantly reduced clinical service delivery time frame. Rapid orthodontic treatment and reduced apical root resorption are probably due to the transient osteopenia induced by the Cort surgery and inspired by

  4. Turbine-blade tip clearance and tip timing measurements using an optical fiber bundle sensor

    Science.gov (United States)

    Garcia, Iker; Beloki, Josu; Zubia, Joseba; Durana, Gaizka; Aldabaldetreku, Gotzon

    2013-04-01

    Traditional limitations of capacitive, inductive or discharging probe sensor for tip timing and tip clearance measurements are overcome by reflective intensity modulated optical fiber sensors. This paper presents the signals and results corresponding to a one stage turbine rig which rotor has 146 blades, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on turbine casing. It is composed of a central illuminating fiber that guides the light from a laser to the turbine blade, and two concentric rings of receiving fibers that collect the reflected light. Two photodetectors turn this reflected light signal from the receiving rings into voltage. The electrical signals are acquired and saved by a high-sample-rate oscilloscope. In tip clearance calculations the ratio of the signals provided by each ring of receiving fibers is evaluated and translated into distance. In the case of tip timing measurements, only one of the signals is considered to get the arrival time of the blade. The differences between the real and theoretical arrival times of the blades are used to obtain the deflections amplitude. The system provides the travelling wave spectrum, which presents the average vibration amplitude of the blades at a certain nodal diameter. The reliability of the results in the turbine rig testing facilities suggests the possibility of performing these measurements in real turbines under real working conditions.

  5. Quantification of tip-broadening in non-contact atomic force microscopy with carbon nanotube tips

    DEFF Research Database (Denmark)

    Meinander, Kristoffer; Jensen, Thomas N.; Simonsen, Soren B.

    2012-01-01

    Carbon nanotube terminated atomic force microscopy (AFM) probes have been used for the imaging of 5 nm wide surface supported Pt nanoclusters by non-contact (dynamic mode) AFM in an ultra-high vacuum. The results are compared to AFM measurements done with conventional Si-tips, as well...

  6. Tipping point analysis of ocean acoustic noise

    Science.gov (United States)

    Livina, Valerie N.; Brouwer, Albert; Harris, Peter; Wang, Lian; Sotirakopoulos, Kostas; Robinson, Stephen

    2018-02-01

    We apply tipping point analysis to a large record of ocean acoustic data to identify the main components of the acoustic dynamical system and study possible bifurcations and transitions of the system. The analysis is based on a statistical physics framework with stochastic modelling, where we represent the observed data as a composition of deterministic and stochastic components estimated from the data using time-series techniques. We analyse long-term and seasonal trends, system states and acoustic fluctuations to reconstruct a one-dimensional stochastic equation to approximate the acoustic dynamical system. We apply potential analysis to acoustic fluctuations and detect several changes in the system states in the past 14 years. These are most likely caused by climatic phenomena. We analyse trends in sound pressure level within different frequency bands and hypothesize a possible anthropogenic impact on the acoustic environment. The tipping point analysis framework provides insight into the structure of the acoustic data and helps identify its dynamic phenomena, correctly reproducing the probability distribution and scaling properties (power-law correlations) of the time series.

  7. Ten tips for authors of scientific articles.

    Science.gov (United States)

    Hong, Sung-Tae

    2014-08-01

    Writing a good quality scientific article takes experience and skill. I propose 'Ten Tips' that may help to improve the quality of manuscripts for scholarly journals. It is advisable to draft first version of manuscript and revise it repeatedly for consistency and accuracy of the writing. During the drafting and revising the following tips can be considered: 1) focus on design to have proper content, conclusion, points compliant with scope of the target journal, appropriate authors and contributors list, and relevant references from widely visible sources; 2) format the manuscript in accordance with instructions to authors of the target journal; 3) ensure consistency and logical flow of ideas and scientific facts; 4) provide scientific confidence; 5) make your story interesting for your readers; 6) write up short, simple and attractive sentences; 7) bear in mind that properly composed and reflective titles increase chances of attracting more readers; 8) do not forget that well-structured and readable abstracts improve citability of your publications; 9) when revising adhere to the rule of 'First and Last' - open your text with topic paragraph and close it with resolution paragraph; 10) use connecting words linking sentences within a paragraph by repeating relevant keywords.

  8. Aperiodicity Correction for Rotor Tip Vortex Measurements

    Science.gov (United States)

    Ramasamy, Manikandan; Paetzel, Ryan; Bhagwat, Mahendra J.

    2011-01-01

    The initial roll-up of a tip vortex trailing from a model-scale, hovering rotor was measured using particle image velocimetry. The unique feature of the measurements was that a microscope was attached to the camera to allow much higher spatial resolution than hitherto possible. This also posed some unique challenges. In particular, the existing methodologies to correct for aperiodicity in the tip vortex locations could not be easily extended to the present measurements. The difficulty stemmed from the inability to accurately determine the vortex center, which is a prerequisite for the correction procedure. A new method is proposed for determining the vortex center, as well as the vortex core properties, using a least-squares fit approach. This approach has the obvious advantage that the properties are derived from not just a few points near the vortex core, but from a much larger area of flow measurements. Results clearly demonstrate the advantage in the form of reduced variation in the estimated core properties, and also the self-consistent results obtained using three different aperiodicity correction methods.

  9. Tipping point analysis of ocean acoustic noise

    Directory of Open Access Journals (Sweden)

    V. N. Livina

    2018-02-01

    Full Text Available We apply tipping point analysis to a large record of ocean acoustic data to identify the main components of the acoustic dynamical system and study possible bifurcations and transitions of the system. The analysis is based on a statistical physics framework with stochastic modelling, where we represent the observed data as a composition of deterministic and stochastic components estimated from the data using time-series techniques. We analyse long-term and seasonal trends, system states and acoustic fluctuations to reconstruct a one-dimensional stochastic equation to approximate the acoustic dynamical system. We apply potential analysis to acoustic fluctuations and detect several changes in the system states in the past 14 years. These are most likely caused by climatic phenomena. We analyse trends in sound pressure level within different frequency bands and hypothesize a possible anthropogenic impact on the acoustic environment. The tipping point analysis framework provides insight into the structure of the acoustic data and helps identify its dynamic phenomena, correctly reproducing the probability distribution and scaling properties (power-law correlations of the time series.

  10. Phosphate starvation of maize inhibits lateral root formation and alters gene expression in the lateral root primordium zone

    Directory of Open Access Journals (Sweden)

    Li Zhaoxia

    2012-06-01

    Full Text Available Abstract Background Phosphorus (P is an essential macronutrient for all living organisms. Maize (Zea mays is an important human food, animal feed and energy crop throughout the world, and enormous quantities of phosphate fertilizer are required for maize cultivation. Thus, it is important to improve the efficiency of the use of phosphate fertilizer for maize. Results In this study, we analyzed the maize root response to phosphate starvation and performed a transcriptomic analysis of the 1.0-1.5 cm lateral root primordium zone. In the growth of plants, the root-to-shoot ratio (R/L was reduced in both low-phosphate (LP and sufficient-phosphate (SP solutions, but the ratio (R/L exhibited by the plants in the LP solution was higher than that of the SP plants. The growth of primary roots was slightly promoted after 6 days of phosphate starvation, whereas the numbers of lateral roots and lateral root primordia were significantly reduced, and these differences were increased when associated with the stress caused by phosphate starvation. Among the results of a transcriptomic analysis of the maize lateral root primordium zone, there were two highlights: 1 auxin signaling participated in the response and the modification of root morphology under low-phosphate conditions, which may occur via local concentration changes due to the biosynthesis and transport of auxin, and LOB domain proteins may be an intermediary between auxin signaling and root morphology; and 2 the observed retardation of lateral root development was the result of co-regulation of DNA replication, transcription, protein synthesis and degradation and cell growth. Conclusions These results indicated that maize roots show a different growth pattern than Arabidopsis under low-phosphate conditions, as the latter species has been observed to halt primary root growth when the root tip comes into contact with low-phosphate media. Moreover, our findings enrich our understanding of plant

  11. Effects of plastic anisotropy on crack-tip behaviour

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  12. Dynamic of cold-atom tips in anharmonic potentials

    Science.gov (United States)

    Menold, Tobias; Federsel, Peter; Rogulj, Carola; Hölscher, Hendrik; Fortágh, József

    2016-01-01

    Background: Understanding the dynamics of ultracold quantum gases in an anharmonic potential is essential for applications in the new field of cold-atom scanning probe microscopy. Therein, cold atomic ensembles are used as sensitive probe tips to investigate nanostructured surfaces and surface-near potentials, which typically cause anharmonic tip motion. Results: Besides a theoretical description of this anharmonic tip motion, we introduce a novel method for detecting the cold-atom tip dynamics in situ and real time. In agreement with theory, the first measurements show that particle interactions and anharmonic motion have a significant impact on the tip dynamics. Conclusion: Our findings will be crucial for the realization of high-sensitivity force spectroscopy with cold-atom tips and could possibly allow for the development of advanced spectroscopic techniques such as Q-control. PMID:28144505

  13. Embolization with the Amplatzer Vascular Plug in TIPS Patients

    International Nuclear Information System (INIS)

    Pattynama, Peter M. T.; Wils, Alexandra; Linden, Edwin van der; Dijk, Lukas C. van

    2007-01-01

    Vessel embolization can be a valuable adjunct procedure in transjugular intrahepatic portosystemic shunt (TIPS). During the creation of a TIPS, embolization of portal vein collaterals supplying esophageal varices may lower the risk of secondary rebleeding. And after creation of a TIPS, closure of the TIPS itself may be indicated if the resulting hepatic encephalopathy severely impairs mental functioning. The Amplatzer Vascular Plug (AVP; AGA Medical, Golden Valley, MN) is well suited for embolization of large-diameter vessels and has been employed in a variety of vascular lesions including congenital arteriovenous shunts. Here we describe the use of the AVP in the context of TIPS to embolize portal vein collaterals (n = 8) or to occlude the TIPS (n = 2)

  14. Plastic responses of native plant root systems to the presence of an invasive annual grass.

    Science.gov (United States)

    Phillips, Allison J; Leger, Elizabeth A

    2015-01-01

    • The ability to respond to environmental change via phenotypic plasticity may be important for plants experiencing disturbances such as climate change and plant invasion. Responding to belowground competition through root plasticity may allow native plants to persist in highly invaded systems such as the cold deserts of the Intermountain West, USA.• We investigated whether Poa secunda, a native bunchgrass, could alter root morphology in response to nutrient availability and the presence of a competitive annual grass. Seeds from 20 families were grown with high and low nutrients and harvested after 50 d, and seeds from 48 families, grown with and without Bromus tectorum, were harvested after ∼2 or 6 mo. We measured total biomass, root mass fraction, specific root length (SRL), root tips, allocation to roots of varying diameter, and plasticity in allocation.• Plants had many parallel responses to low nutrients and competition, including increased root tip production, a trait associated with tolerance to reduced resources, though families differed in almost every trait and correlations among trait changes varied among experiments, indicating flexibility in plant responses. Seedlings actively increased SRL and fine root allocation under competition, while older seedlings also increased coarse root allocation, a trait associated with increased tolerance, and increased root mass fraction.• The high degree of genetic variation for root plasticity within natural populations could aid in the long-term persistence of P. secunda because phenotypic plasticity may allow native species to persist in invaded and fluctuating resource environments. © 2015 Botanical Society of America, Inc.

  15. Influence of salicylic acid pretreatment on seeds germination and some defence mechanisms of Zea mays plants under copper stress.

    Science.gov (United States)

    Moravcová, Šárka; Tůma, Jiří; Dučaiová, Zuzana Kovalíková; Waligórski, Piotr; Kula, Monika; Saja, Diana; Słomka, Aneta; Bąba, Wojciech; Libik-Konieczny, Marta

    2018-01-01

    The study was focused on the influence of salicylic acid (SA) on maize seeds germination and on some physiological and biochemical processes in maize plants growing in the hydroponic culture under copper (Cu) stress. A significant influence of SA pretreatment on the advanced induction of the maize seeds metabolic activity and the level of the endogenous SA in germinated seeds and developing roots have been stated. Although, the ability of maize seeds to uptake SA and accumulate it in the germinated roots was confirmed, the growth inhibition of Cu-stressed maize seedlings was not ameliorated by SA seeds pretreatment. Cu-stressed plants exhibited a decrease in the photosynthetic pigment concentration and the increase in non-photochemical quenching (NPQ) - an indicator of an excess energy in PSII antenna assemblies lost as a heat. The amelioration effect of SA application was found only for carotenoids content which increased in stressed plants. It was also shown that maize roots growing in stress conditions significantly differed in the chemical composition in comparison to the roots of control plants, but the SA pretreatment did not affect these differences. On the other hand, it was found that SA seed pretreatment significantly influenced the ability of stressed plants to accumulate copper in the roots. It was stated that a higher level of exogenous SA application led to a lower accumulation of Cu ions in maize roots. Cu-stressed plants exhibited higher oxidative stress in roots than in leaves which was manifested as an increase in the concentration of hydrogen peroxide due to stress factor application. We observed an increase in catalase (CAT) activity in leaves of Cu-stressed plants which corresponded with a lower H 2 O 2 content when compared with roots where the hydrogen peroxide level was higher, and the inhibition of the CAT activity was found. Furthermore, we found that the SA seed pretreatment led to a decrease in the H 2 O 2 content in the roots of the Cu

  16. Enzymatic hydrolysis of pretreated soybean straw

    International Nuclear Information System (INIS)

    Xu Zhong; Wang Qunhui; Jiang Zhaohua; Yang Xuexin; Ji Yongzhen

    2007-01-01

    In order to produce lactic acid, from agricultural residues such as soybean straw, which is a raw material for biodegradable plastic production, it is necessary to decompose the soybean straw into soluble sugars. Enzymatic hydrolysis is one of the methods in common use, while pretreatment is the effective way to increase the hydrolysis rate. The optimal conditions of pretreatment using ammonia and enzymatic hydrolysis of soybean straw were determined. Compared with the untreated straw, cellulose in straw pretreated by ammonia liquor (10%) soaking for 24 h at room temperature increased 70.27%, whereas hemicellulose and lignin in pretreated straw decreased to 41.45% and 30.16%, respectively. The results of infrared spectra (IR), scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis also showed that the structure and the surface of the straw were changed through pretreatment that is in favor of the following enzymatic hydrolysis. maximum enzymatic hydrolysis rate of 51.22% was achieved at a substrate concentration of 5% (w/v) at 50 deg. C and pH 4.8 using cellulase (50 fpu/g of substrate) for 36 h

  17. Temperature-controlled irrigated tip radiofrequency catheter ablation

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, Adrian

    1998-01-01

    INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

  18. DO SLOVENIAN DEALERS USE TECHNIQUES FOR INCREASING THEIR TIPS?

    Directory of Open Access Journals (Sweden)

    Andrej Raspor

    2016-05-01

    Full Text Available In 1996 Michael Lynn introduced the idea that restaurant managers could increase tips for their waiters and thus increase turnover by training the waiters to engage tip-enhancing behaviours. Since then, the list of tip-enhancing behaviours has expanded. Therefore the potential to increase tips is more accessible. The purpose of this paper was to examine how Slovenian dealers use strategies to increase their tips. We tested fourteen techniques to increase tips. The study was carried out among 473 gaming employees, 279 of which are dealers, in the Slovenian gaming industry, in order to find out how they use these techniques and which of them can bring about an increase in their tips. The study showed that Slovenian dealers mostly do not use these techniques, and that the dealers who do use them tend to receive tips more often. The findings imply that managers and employees should be informed of these techniques in order to increase tips and their overall income. Practical implications are that we suggest that management considers these ideas for increasing flexibility and reducing the cost of work: (1 informing dealers on ways of increasing tips, (2 including the acquisition of this specific knowledge in their career plans, (3 carrying out a reform of the reward system which would include tips. Social implications will be shown in a higher gaming revenue. It is very likely – as shown in our research – that employees will receive higher wages as these will be topped up by tips. The state, in turn, will collect more taxes.

  19. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Directory of Open Access Journals (Sweden)

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  20. Root lattices and quasicrystals

    Science.gov (United States)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown that root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All noncrystallographic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  1. Roots and routes

    DEFF Research Database (Denmark)

    Christensen, Ann-Dorte; Jensen, Sune Qvotrup

    2011-01-01

    This article is about transnational migrants, how they construct belonging to ‘new’ places where they have arrived, and how the feelings of belonging to their places of origin change when they go back. The theoretical part of the article outlines the relationship between migration and belonging...... arguing that there is a dynamic interplay between roots and routes in people's lives. The empirical point of departure is narratives about roots and routes by ethnic minorities settled in Aalborg East, an underprivileged neighbourhood in northern Denmark. One of the main findings is a gap between....... A somewhat paradoxical finding is that it appears to be more difficult for transnational migrants to maintain their roots in the country of origin when they go back than it was to establish new roots in the host country...

  2. An aluminum influence on root circumnutation in dark revealed by a new super-HARP (high-gain avalanche rushing amorphous photoconductor) camera.

    Science.gov (United States)

    Hayashi, Yoshitake; Nishiyama, Hiroki; Tanoi, Keitaro; Ohya, Tomoyuki; Nihei, Naoto; Tanioka, Kenkichi; Nakanishi, Tomoko M

    2004-03-01

    The circumnutation of a rice root under dark conditions was observed using a highly sensitive camera, a new super-HARP camera. A rice root showed regular rhythmic movement with fixed angle. When treated with Al (5 microM AlCl3), the rotation angle of the root tip was drastically decreased and then the movement was resumed again, whereas the root elongation rate was constant. With the increase of Al concentration, the cycle-fading period became shorter. This is the first report to show that an Al treatment ceased the rotation movement of the root but not elongation.

  3. Energy Savers Tips on Saving Energy& Money at Home

    Energy Technology Data Exchange (ETDEWEB)

    2003-06-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances

  4. Is a Drain Tip Culture Required After Spinal Surgery?

    Science.gov (United States)

    Kobayashi, Kazuyoshi; Imagama, Shiro; Ito, Zenya; Ando, Kei; Yagi, Hideki; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Ishiguro, Naoki

    2017-10-01

    The efficacy of use of a drain tip culture for early detection of surgical-site infection (SSI) was investigated in 329 patients after spinal surgery. To examine the efficacy of a wound drain tip culture for detection of SSI in spinal surgery. A complication of SSI after spinal surgery has high associated morbidity and mortality, and is often difficult to treat. The subjects were patients who underwent spinal surgery at our institution between January 2010 and March 2013. All subjects were treated with antimicrobial prophylaxis based on evidence-based guidelines and were followed for at least 6 months after surgery. Data from culture studies using the distal tip of the wound drain were used for analysis. Drain tip cultures were positive in 34 cases and there were 19 SSIs. Ten of the 34-tip culture-positive wounds developed SSI. Drain tip cultures had a sensitivity of 52%, specificity of 92%, positive predictive value (PPV) of 29%, and negative predictive value of 97% for predicting a wound infection. The association between a positive suction tip culture and wound infection was significant (P<0.05). The PPV for SSI was 60% in cases in which methicillin-resistant bacteria were detected in a drain tip, and the SSI rate in these cases differed significantly compared with those with non-methicillin-resistant bacteria (P=0.01). A drain tip culture is useful for early detection of SSI caused by methicillin-resistant bacteria.

  5. Microneedles array with biodegradable tips for transdermal drug delivery

    Science.gov (United States)

    Iliescu, Ciprian; Chen, Bangtao; Wei, Jiashen; Tay, Francis E. H.

    2008-12-01

    The paper presented an enhancement solution for transdermal drug delivery using microneedles array with biodegradable tips. The microneedles array was fabricated by using deep reactive ion etching (DRIE) and the biodegradable tips were made to be porous by electrochemical etching process. The porous silicon microneedle tips can greatly enhance the transdermal drug delivery in a minimum invasion, painless, and convenient manner, at the same time; they are breakable and biodegradable. Basically, the main problem of the silicon microneedles consists of broken microneedles tips during the insertion. The solution proposed is to fabricate the microneedle tip from a biodegradable material - porous silicon. The silicon microneedles are fabricated using DRIE notching effect of reflected charges on mask. The process overcomes the difficulty in the undercut control of the tips during the classical isotropic silicon etching process. When the silicon tips were formed, the porous tips were then generated using a classical electrochemical anodization process in MeCN/HF/H2O solution. The paper presents the experimental results of in vitro release of calcein and BSA with animal skins using a microneedle array with biodegradable tips. Compared to the transdermal drug delivery without any enhancer, the microneedle array had presented significant enhancement of drug release.

  6. Terahertz Nanofocusing with Cantilevered Terahertz-Resonant Antenna Tips.

    Science.gov (United States)

    Mastel, Stefan; Lundeberg, Mark B; Alonso-González, Pablo; Gao, Yuanda; Watanabe, Kenji; Taniguchi, Takashi; Hone, James; Koppens, Frank H L; Nikitin, Alexey Y; Hillenbrand, Rainer

    2017-11-08

    We developed THz-resonant scanning probe tips, yielding strongly enhanced and nanoscale confined THz near fields at their tip apex. The tips with length in the order of the THz wavelength (λ = 96.5 μm) were fabricated by focused ion beam (FIB) machining and attached to standard atomic force microscopy (AFM) cantilevers. Measurements of the near-field intensity at the very tip apex (25 nm radius) as a function of tip length, via graphene-based (thermoelectric) near-field detection, indicate their first and second order geometrical antenna resonances for tip length of 33 and 78 μm, respectively. On resonance, we find that the near-field intensity is enhanced by one order of magnitude compared to tips of 17 μm length (standard AFM tip length), which is corroborated by numerical simulations that further predict remarkable intensity enhancements of about 10 7 relative to the incident field. Because of the strong field enhancement and standard AFM operation of our tips, we envision manifold and straightforward future application in scattering-type THz near-field nanoscopy and THz photocurrent nanoimaging, nanoscale nonlinear THz imaging, or nanoscale control and manipulation of matter employing ultrastrong and ultrashort THz pulses.

  7. Energy Savers: Tips on Saving Money & Energy at Home

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-12-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  8. Dependence of electric field on STM tip preparation

    DEFF Research Database (Denmark)

    Huang, D.H.; Grey, Francois; Aono, M.

    1998-01-01

    Voltage pulses applied between an STM tip and a surface can modify the surface on the nanometer scale due to electric-field-induced evaporation. However, at present, different groups have achieved surface modification with quite different bias conditions, and it is still difficult to obtain high...... reproducibility in such experiments. In this paper, we measure the tip displacement during a pulse at constant tunnelling current, and deduce that the electric field produced by the pulse depends in a systematic way on tip preparation, The results show how differences in tip preparation can be a major source...

  9. Energy Saver: Tips on Saving Money & Energy at Home

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  10. Wettability of AFM tip influences the profile of interfacial nanobubbles

    Science.gov (United States)

    Teshima, Hideaki; Takahashi, Koji; Takata, Yasuyuki; Nishiyama, Takashi

    2018-02-01

    To accurately characterize the shape of interfacial nanobubbles using atomic force microscopy (AFM), we investigated the effect of wettability of the AFM tip while operating in the peak force tapping (PFT) mode. The AFM tips were made hydrophobic and hydrophilic by Teflon AF coating and oxygen plasma treatment, respectively. It was found that the measured base radius of nanobubbles differed between AFM height images and adhesion images, and that this difference depended on the tip wettability. The force curves obtained during the measurements were also different depending on the wettability, especially in the range of the tip/nanobubble interaction and in the magnitude of the maximum attractive force in the retraction period. The difference suggests that hydrophobic tips penetrate the gas/liquid interface of the nanobubbles, with the three phase contact line being pinned on the tip surface; hydrophilic tips on the other hand do not penetrate the interface. We then quantitatively estimated the pinning position and recalculated the true profiles of the nanobubbles by comparing the height images and adhesion images. As the AFM tip was made more hydrophilic, the penetration depth decreased and eventually approached zero. This result suggests that the PFT measurement using a hydrophilic tip is vital for the acquisition of reliable nanobubble profiles.

  11. On open and closed tips of bunsen burner flames

    Science.gov (United States)

    Kozlovsky, G.; Sivashinsky, G. I.

    1994-04-01

    An adiabatic, constant-density reaction-diffusion-advection model for the Bunsen burner flame tip is studied numerically. It is shown that for Lewis numbers exceeding unity the reaction rate and flame speed gradually increase toward the flame tip. For small Lewis numbers the picture is quite different. The reaction rate drops near the tip. In spite of this the flame survives and, moreover, manages to consume all the fuel supplied to the reaction zone. There is no leakage of the fuel through the front. The flame speed varies nonmonotonously along the front from gradual reduction to steep increase near the tip.

  12. Energy Savers: Tips on Saving Money & Energy at Home

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-05-01

    Provides consumers with home energy and money savings tips such as insulation, weatherization, heating, cooling, water heating, energy efficient windows, landscaping, lighting, and energy efficient appliances.

  13. The Early Entry of Al into Cells of Intact Soybean Roots (A Comparison of Three Developmental Root Regions Using Secondary Ion Mass Spectrometry Imaging).

    Science.gov (United States)

    Lazof, D. B.; Goldsmith, J. G.; Rufty, T. W.; Linton, R. W.

    1996-11-01

    Al localization was compared in three developmental regions of primary root of an Al-sensitive soybean (Glycine max) genotype using secondary ion mass spectrometry. In cryosections obtained after a 4-h exposure to 38 [mu]M [Al3+], Al had penetrated across the root and into the stele in all three regions. Although the greatest localized Al concentration was consistently at the root periphery, the majority of the Al in each region had accumulated in cortical cells. It was apparent that the secondary ion mass spectrometry 27Al+ mass signal was spread throughout the intracellular area and was not particularly intense in the cell wall. Inclusion of some cell wall in determinations of the Al levels across the root radius necessitated that these serve as minimal estimates for intracellular Al. Total accumulation of intracellular Al for each region was 60, 73, and 210 nmol g-1 fresh weight after 4 h, increasing with root development. Early metabolic responses to external Al, including those that have been reported deep inside the root and in mature regions, might result directly from intracellular Al. These responses might include ion transport events at the endodermis of mature roots or events associated with lateral root emergence, as well as events within the root tip.

  14. Fabrication of a quartz optical fiber tip for dental treatment with Nd:YAG laser—Proposal of a new process with TiO 2 powder

    Science.gov (United States)

    Furumoto, Tatsuaki; Aoki, Shintaro; Ueda, Takashi; Hosokawa, Akira

    2009-09-01

    In dental treatment with Nd:YAG laser beam, a quartz optical fiber is generally used to transmit the laser beam, which is irradiated to the hard and soft tissues for a caries treatment and a periodontal tissue excision. Since a normal optical fiber, which the laser beam comes out from the tip of the fiber, has difficulty irradiating to a narrow space and an inner root canal uniformly, it is effective to use a processed optical fiber tip from which is obtained a diffused and circumferential laser beam. In this paper, a new process to obtain these laser beams with TiO 2 powder is proposed, and the characteristics and the performances of the processed optical fiber were investigated. An experimental instrument was developed to measure the energy partition radiated from the processed fiber tip, and the ratio of a straight beam, a sideways beam and heat generated by the absorption of the laser beam was measured in each condition. As a result, the ratio of an energy partition was controllable by changing the incidence parameter to process the fiber tip, and the processed fiber tip corresponding to the clinical purpose could be obtained. The parameters which affected the processability of the fiber tip were processing time and incidence laser energy. The prepared cavity with processed fiber on the enamel was influenced by a straight beam, and the removal of enamel to the depth direction was controllable by using the processed fiber.

  15. Expression of the citrus CsTIP2;1 gene improves tobacco plant growth, antioxidant capacity and physiological adaptation under stress conditions.

    Science.gov (United States)

    Martins, Cristina P S; Neves, Diana M; Cidade, Luciana C; Mendes, Amanda F S; Silva, Delmira C; Almeida, Alex-Alan F; Coelho-Filho, Mauricio A; Gesteira, Abelmon S; Soares-Filho, Walter S; Costa, Marcio G C

    2017-05-01

    Overexpression of the citrus CsTIP2;1 improves plant growth and tolerance to salt and drought stresses by enhancing cell expansion, H 2 O 2 detoxification and stomatal conductance. Tonoplast intrinsic proteins (TIPs) are a subfamily of aquaporins, belonging to the major intrinsic protein family. In a previous study, we have shown that a citrus TIP isoform, CsTIP2;1, is highly expressed in leaves and also transcriptionally regulated in leaves and roots by salt and drought stresses and infection by 'Candidatus Liberibacter asiaticus', the causal agent of the Huanglongbing disease, suggesting its involvement in the regulation of the flow of water and nutrients required during both normal growth and stress conditions. Here, we show that the overexpression of CsTIP2;1 in transgenic tobacco increases plant growth under optimal and water- and salt-stress conditions and also significantly improves the leaf water and oxidative status, photosynthetic capacity, transpiration rate and water use efficiency of plants subjected to a progressive soil drying. These results correlated with the enhanced mesophyll cell expansion, midrib aquiferous parenchyma abundance, H 2 O 2 detoxification and stomatal conductance observed in the transgenic plants. Taken together, our results indicate that CsTIP2;1 plays an active role in regulating the water and oxidative status required for plant growth and adaptation to stressful environmental conditions and may be potentially useful for engineering stress tolerance in citrus and other crop plants.

  16. Heterologous expression of the wheat aquaporin gene TaTIP2;2 compromises the abiotic stress tolerance of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Chunhui Xu

    Full Text Available Aquaporins are channel proteins which transport water across cell membranes. We show that the bread wheat aquaporin gene TaTIP2;2 maps to the long arm of chromosome 7b and that its product localizes to the endomembrane system. The gene is expressed constitutively in both the root and the leaf, and is down-regulated by salinity and drought stress. Salinity stress induced an increased level of C-methylation within the CNG trinucleotides in the TaTIP2;2 promoter region. The heterologous expression of TaTIP2;2 in Arabidopsis thaliana compromised its drought and salinity tolerance, suggesting that TaTIP2;2 may be a negative regulator of abiotic stress. The proline content of transgenic A. thaliana plants fell, consistent with the down-regulation of P5CS1, while the expression of SOS1, SOS2, SOS3, CBF3 and DREB2A, which are all stress tolerance-related genes acting in an ABA-independent fashion, was also down-regulated. The supply of exogenous ABA had little effect either on TaTIP2;2 expression in wheat or on the phenotype of transgenic A. thaliana. The expression level of the ABA signalling genes ABI1, ABI2 and ABF3 remained unaltered in the transgenic A. thaliana plants. Thus TaTIP2;2 probably regulates the response to stress via an ABA-independent pathway(s.

  17. TIPS Placement in Swine, Guided by Electromagnetic Real-Time Needle Tip Localization Displayed on Previously Acquired 3-D CT

    International Nuclear Information System (INIS)

    Solomon, Stephen B.; Magee, Carolyn; Acker, David E.; Venbrux, Anthony C.

    1999-01-01

    Purpose: To determine the feasibility of guiding a transjugular intrahepatic portosystemic shunt (TIPS) procedure with an electromagnetic real-time needle tip position sensor coupled to previously acquired 3-dimensional (3-D) computed tomography (CT) images. Methods: An electromagnetic position sensor was placed at the tip of a Colapinto needle. The real-time position and orientation of the needle tip was then displayed on previously acquired 3-D CT images which were registered with the five swine. Portal vein puncture was then attempted in all animals. Results: The computer calculated accuracy of the position sensor was on average 3 mm. Four of five portal vein punctures were successful. In the successes, only one or two attempts were necessary and success was achieved in minutes. Conclusion: A real-time position sensor attached to the tip of a Colapinto needle and coupled to previously acquired 3-D CT images may potentially aid in entering the portal vein during the TIPS procedure

  18. Temperature Modelling of the Biomass Pretreatment Process

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail; Blanke, Mogens; Jensen, Jakob M.

    2012-01-01

    In a second generation biorefinery, the biomass pretreatment stage has an important contribution to the efficiency of the downstream processing units involved in biofuel production. Most of the pretreatment process occurs in a large pressurized thermal reactor that presents an irregular temperature...... distribution. Therefore, an accurate temperature model is critical for observing the biomass pretreatment. More than that, the biomass is also pushed with a constant horizontal speed along the reactor in order to ensure a continuous throughput. The goal of this paper is to derive a temperature model...... that captures the environmental temperature differences inside the reactor using distributed parameters. A Kalman filter is then added to account for any missing dynamics and the overall model is embedded into a temperature soft sensor. The operator of the plant will be able to observe the temperature in any...

  19. Cold storage of rooted and non-rooted carnation cuttings

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... The specific objectives of this study were to evaluate the effect of storage duration on the survival rate of rooted cuttings and to determine the rooting and survival rates of non-rooted cuttings for two standard carnation cultivars (that is., Dianora and Vittorio). The survival rates of rooted cuttings showed ...

  20. [Study on tissue culture and plant regeneration of the stem-tips and buds of Periploca forrestii].

    Science.gov (United States)

    Liu, Zhi-Fei; Gao, Jie; Niu, Ya-Hui; Shi, Lei; Chen, Tao-Tao

    2011-11-01

    To establish the rapid propagation systems of the stem-tips and buds of Periploca forrestii. Inserted the stem-tips and buds of Periploca forrestii into MS medium with different concentrations of 6-BA, NAA and 2.4-D and induced them growing into complete plants. The optimal culture medium for bud induction is MS + 6-BA 1.0 mg/L + NAA 0.3 mg/L and the bud induction rate can reach 86.29%. The optimal culture medium for stem-tips induction is MS +6-BA 2.0 mg/L + NAA 0.5 mg/L and the bud induction rate can reach 86.29%. The optimal culture medium for bud multiplication is MS + 6-BA 2.0 mg/L + NAA 0.1 mg/L and the multiplication coefficient can reach 2.10. The best rooting medium is 1/2 MS + IBA 0.5 mg/L and the rooting rate is 53.33%.