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Sample records for regulating secondary wall

  1. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation

    Directory of Open Access Journals (Sweden)

    Kouki eYoshida

    2013-10-01

    Full Text Available Plant tissues that require structural rigidity synthesize a thick, strong secondary cell wall of lignin, cellulose and hemicelluloses in a complicated bridged structure. Master regulators of secondary wall synthesis were identified in dicots, and orthologs of these regulators have been identified in monocots, but regulation of secondary cell wall formation in monocots has not been extensively studied. Here we demonstrate that the rice transcription factors SECONDARY WALL NAC DOMAIN PROTEINs (SWNs can regulate secondary wall formation in rice (Oryza sativa and are potentially useful for engineering the monocot cell wall. The OsSWN1 promoter is highly active in sclerenchymatous cells of the leaf blade and less active in xylem cells. By contrast, the OsSWN2 promoter is highly active in xylem cells and less active in sclerenchymatous cells. OsSWN2 splicing variants encode two proteins; the shorter protein (OsSWN2S has very low transcriptional activation ability, but the longer protein (OsSWN2L and OsSWN1 have strong transcriptional activation ability. In rice, expression of an OsSWN2S chimeric repressor, driven by the OsSWN2 promoter, resulted in stunted growth and para-wilting (leaf rolling and browning under normal water conditions due to impaired vascular vessels. The same OsSWN2S chimeric repressor, driven by the OsSWN1 promoter, caused a reduction of cell wall thickening in sclerenchymatous cells, a drooping leaf phenotype, reduced lignin and xylose contents and increased digestibility as forage. These data suggest that OsSWNs regulate secondary wall formation in rice and manipulation of OsSWNs may enable improvements in monocotyledonous crops for forage or biofuel applications.

  2. Navigating the transcriptional roadmap regulating plant secondary cell wall deposition

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    Steven Grant Hussey

    2013-08-01

    Full Text Available The current status of lignocellulosic biomass as an invaluable resource in industry, agriculture and health has spurred increased interest in understanding the transcriptional regulation of secondary cell wall (SCW biosynthesis. The last decade of research has revealed an extensive network of NAC, MYB and other families of transcription factors regulating Arabidopsis SCW biosynthesis, and numerous studies have explored SCW-related transcription factors in other dicots and monocots. Whilst the general structure of the Arabidopsis network has been a topic of several reviews, they have not comprehensively represented the detailed protein-DNA and protein-protein interactions described in the literature, and an understanding of network dynamics and functionality has not yet been achieved for SCW formation. Furthermore the methodologies employed in studies of SCW transcriptional regulation have not received much attention, especially in the case of non-model organisms. In this review, we have reconstructed the most exhaustive literature-based network representations to date of SCW transcriptional regulation in Arabidopsis. We include a manipulable Cytoscape representation of the Arabidopsis SCW transcriptional network to aid in future studies, along with a list of supporting literature for each documented interaction. Amongst other topics, we discuss the various components of the network, its evolutionary conservation in plants, putative modules and dynamic mechanisms that may influence network function, and the approaches that have been employed in network inference. Future research should aim to better understand network function and its response to dynamic perturbations, whilst the development and application of genome-wide approaches such as ChIP-seq and systems genetics are in progress for the study of SCW transcriptional regulation in non-model organisms.

  3. Current Models for Transcriptional Regulation of Secondary Cell Wall Biosynthesis in Grasses

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    Xiaolan Rao

    2018-04-01

    Full Text Available Secondary cell walls mediate many crucial biological processes in plants including mechanical support, water and nutrient transport and stress management. They also provide an abundant resource of renewable feed, fiber, and fuel. The grass family contains the most important food, forage, and biofuel crops. Understanding the regulatory mechanism of secondary wall formation in grasses is necessary for exploiting these plants for agriculture and industry. Previous research has established a detailed model of the secondary wall regulatory network in the dicot model species Arabidopsis thaliana. Grasses, branching off from the dicot ancestor 140–150 million years ago, display distinct cell wall morphology and composition, suggesting potential for a different secondary wall regulation program from that established for dicots. Recently, combined application of molecular, genetic and bioinformatics approaches have revealed more transcription factors involved in secondary cell wall biosynthesis in grasses. Compared with the dicots, grasses exhibit a relatively conserved but nevertheless divergent transcriptional regulatory program to activate their secondary cell wall development and to coordinate secondary wall biosynthesis with other physiological processes.

  4. The receptor-like kinase AtVRLK1 regulates secondary cell wall thickening.

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    Huang, Cheng; Zhang, Rui; Gui, Jinshan; Zhong, Yu; Li, Laigeng

    2018-04-20

    During the growth and development of land plants, some specialized cells, such as tracheary elements, undergo secondary cell wall thickening. Secondary cell walls contain additional lignin, compared with primary cell walls, thus providing mechanical strength and potentially improving defenses against pathogens. However, the molecular mechanisms that initiate wall thickening are unknown. In this study, we identified an Arabidopsis thaliana leucine-rich repeat receptor-like kinase, encoded by AtVRLK1 (Vascular-Related RLK 1), that is specifically expressed in cells undergoing secondary cell wall thickening. Suppression of AtVRLK1expression resulted in a range of phenotypes that included retarded early elongation of the inflorescence stem, shorter fibers, slower root growth, and shorter flower filaments. In contrast, upregulation of AtVRLK1 led to longer fiber cells, reduced secondary cell wall thickening in fiber and vessel cells, and defects in anther dehiscence. Molecular and cellular analyses showed that downregulation of AtVRLK1 promoted secondary cell wall thickening and upregulation of AtVRLK1 enhanced cell elongation and inhibited secondary cell wall thickening. We propose that AtVRLK1 functions as a signaling component in coordinating cell elongation and cell wall thickening during growth and development. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

  5. Isolation of a novel cell wall architecture mutant of rice with defective Arabidopsis COBL4 ortholog BC1 required for regulated deposition of secondary cell wall components.

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    Sato, Kanna; Suzuki, Ryu; Nishikubo, Nobuyuki; Takenouchi, Sachi; Ito, Sachiko; Nakano, Yoshimi; Nakaba, Satoshi; Sano, Yuzou; Funada, Ryo; Kajita, Shinya; Kitano, Hidemi; Katayama, Yoshihiro

    2010-06-01

    The plant secondary cell wall is a highly ordered structure composed of various polysaccharides, phenolic components and proteins. Its coordinated regulation of a number of complex metabolic pathways and assembly has not been resolved. To understand the molecular mechanisms that regulate secondary cell wall synthesis, we isolated a novel rice mutant, cell wall architecture1 (cwa1), that exhibits an irregular thickening pattern in the secondary cell wall of sclerenchyma, as well as culm brittleness and reduced cellulose content in mature internodes. Light and transmission electron microscopy revealed that the cwa1 mutant plant has regions of local aggregation in the secondary cell walls of the cortical fibers in its internodes, showing uneven thickness. Ultraviolet microscopic observation indicated that localization of cell wall phenolic components was perturbed and that these components abundantly deposited at the aggregated cell wall regions in sclerenchyma. Therefore, regulation of deposition and assembly of secondary cell wall materials, i.e. phenolic components, appear to be disturbed by mutation of the cwa1 gene. Genetic analysis showed that cwa1 is allelic to brittle culm1 (bc1), which encodes the glycosylphosphatidylinositol-anchored COBRA-like protein specifically in plants. BC1 is known as a regulator that controls the culm mechanical strength and cellulose content in the secondary cell walls of sclerenchyma, but the precise function of BC1 has not been resolved. Our results suggest that CWA1/BC1 has an essential role in assembling cell wall constituents at their appropriate sites, thereby enabling synthesis of solid and flexible internodes in rice.

  6. Identification of novel transcription factors regulating secondary cell wall formation in Arabidopsis

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    Hua eCassan-Wang

    2013-06-01

    Full Text Available The presence of lignin in secondary cell walls (SCW is a major factor preventing hydrolytic enzymes from gaining access to cellulose, thereby limiting the saccharification potential of plant biomass. To understand how lignification is regulated is a prerequisite for selecting plant biomass better adapted to bioethanol production. Because transcriptional regulation is a major mechanism controlling the expression of genes involved in lignin biosynthesis, our aim was to identify novel transcription factors dictating lignin profiles in the model plant Arabidopsis. To this end, we have developed a post-genomic approach by combining four independent in-house SCW-related transcriptome datasets obtained from (i the fiber cell wall-deficient wat1 Arabidopsis mutant, (ii Arabidopsis lines over-expressing either the master regulatory activator EgMYB2 or (iii the repressor EgMYB1 and finally (iv Arabidopsis orthologs of Eucalyptus xylem-expressed genes. This allowed us to identify 502 up- or down-regulated transcription factors. We preferentially selected those present in more than one dataset and further analyzed their in silico expression patterns as an additional selection criteria. This selection process led to 80 candidates. Notably, 16 of them were already proven to regulate SCW formation, thereby validating the overall strategy. Then, we phenotyped 43 corresponding mutant lines focusing on histological observations of xylem and interfascicular fibers. This phenotypic screen revealed six mutant lines exhibiting altered lignification patterns. Two of them (blh6 and a zinc finger transcription factor presented hypolignified SCW. Three others (myb52, myb-like TF, hb5 showed hyperlignified SCW whereas the last one (hb15 showed ectopic lignification. In addition, our meta-analyses highlighted a reservoir of new potential regulators adding to the gene network regulating SCW but also opening new avenues to ultimately improve SCW composition for biofuel

  7. Regulation of auxin on secondary cell wall cellulose biosynthesis in developing cotton fibers

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    Cotton (Gossypium hirsutum L.) fibers are unicellular trichomes that differentiate from epidermal cells of developing cotton ovules. Mature fibers exhibit thickened secondary walls composed of nearly pure cellulose. Cotton fiber development is divided into four overlapping phases, 1) initiation sta...

  8. Regulation of cell wall biosynthesis.

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    Zhong, Ruiqin; Ye, Zheng-Hua

    2007-12-01

    Plant cell walls differ in their amount and composition among various cell types and even in different microdomains of the wall of a given cell. Plants must have evolved regulatory mechanisms controlling biosynthesis, targeted secretion, and assembly of wall components to achieve the heterogeneity in cell walls. A number of factors, including hormones, the cytoskeleton, glycosylphosphatidylinositol-anchored proteins, phosphoinositides, and sugar nucleotide supply, have been implicated in the regulation of cell wall biosynthesis or deposition. In the past two years, there have been important discoveries in transcriptional regulation of secondary wall biosynthesis. Several transcription factors in the NAC and MYB families have been shown to be the key switches for activation of secondary wall biosynthesis. These studies suggest a transcriptional network comprised of a hierarchy of transcription factors is involved in regulating secondary wall biosynthesis. Further investigation and integration of the regulatory players participating in the making of cell walls will certainly lead to our understanding of how wall amounts and composition are controlled in a given cell type. This may eventually allow custom design of plant cell walls on the basis of our needs.

  9. PtrWRKY19, a novel WRKY transcription factor, contributes to the regulation of pith secondary wall formation in Populus trichocarpa

    OpenAIRE

    Li Yang; Xin Zhao; Fan Yang; Di Fan; Yuanzhong Jiang; Keming Luo

    2016-01-01

    WRKY proteins are one of the largest transcription factor families in higher plants and play diverse roles in various biological processes. Previous studies have shown that some WRKY members act as negative regulators of secondary cell wall formation in pith parenchyma cells. However, the regulatory mechanism of pith secondary wall formation in tree species remains largely unknown. In this study, PtrWRKY19 encoding a homolog of Arabidopsis WRKY12 was isolated from Populus trichocarpa. PtrWRKY...

  10. Reconstitution of a secondary cell wall in a secondary cell wall-deficient Arabidopsis mutant.

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    Sakamoto, Shingo; Mitsuda, Nobutaka

    2015-02-01

    The secondary cell wall constitutes a rigid frame of cells in plant tissues where rigidity is required. Deposition of the secondary cell wall in fiber cells contributes to the production of wood in woody plants. The secondary cell wall is assembled through co-operative activities of many enzymes, and their gene expression is precisely regulated by a pyramidal cascade of transcription factors. Deposition of a transmuted secondary cell wall in empty fiber cells by expressing selected gene(s) in this cascade has not been attempted previously. In this proof-of-concept study, we expressed chimeric activators of 24 transcription factors that are preferentially expressed in the stem, in empty fiber cells of the Arabidopsis nst1-1 nst3-1 double mutant, which lacks a secondary cell wall in fiber cells, under the control of the NST3 promoter. The chimeric activators of MYB46, SND2 and ANAC075, as well as NST3, reconstituted a secondary cell wall with different characteristics from those of the wild type in terms of its composition. The transgenic lines expressing the SND2 or ANAC075 chimeric activator showed increased glucose and xylose, and lower lignin content, whereas the transgenic line expressing the MYB46 chimeric activator showed increased mannose content. The expression profile of downstream genes in each transgenic line was also different from that of the wild type. This study proposed a new screening strategy to identify factors of secondary wall formation and also suggested the potential of the artificially reconstituted secondary cell walls as a novel raw material for production of bioethanol and other chemicals. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  11. Functional characterization of secondary wall deposition regulating transcription factors MusaVND2 and MusaVND3 in transgenic banana plants.

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    Negi, Sanjana; Tak, Himanshu; Ganapathi, T R

    2016-03-01

    NAM, ATAF, and CUC (NAC) domain-containing proteins are plant-specific transcription factors involved in stress responses and developmental regulation. MusaVND2 and MusaVND3 are vascular-related NAC domain-containing genes encoding for nuclear-localized proteins. The transcript level of MusaVND2 and MusaVND3 are gradually induced after induction of lignification conditions in banana embryogenic cells. Banana embryogenic cells differentiated to tracheary element-like cells after overexpression of MusaVND2 and MusaVND3 with a differentiation frequency of 63.5 and 23.4 %, respectively, after ninth day. Transgenic banana plants overexpressing either of MusaVND2 or MusaVND3 showed ectopic secondary wall deposition as well as transdifferentiation of cells into tracheary elements. Transdifferentiation to tracheary element-like cells was observed in cortical cells of corm and in epidermal and mesophyll cells of leaves of transgenic plants. Elevated levels of lignin and crystalline cellulose were detected in the transgenic banana lines than control plants. The results obtained are useful for understanding the molecular regulation of secondary wall development in banana.

  12. Transcriptional regulatory network controlling secondary cell wall ...

    African Journals Online (AJOL)

    Secondary wall is an abundant component of plant biomass and has a potential to be a renewable resource of bioenergy and biomaterials. It is important to unravel the molecular mechanism underlying secondary wall formation and how it contributes to plant biomass production. In this review, we summarized the potential ...

  13. Tissue and cell-specific transcriptomes in cotton reveal the subtleties of gene regulation underlying the diversity of plant secondary cell walls.

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    MacMillan, Colleen P; Birke, Hannah; Chuah, Aaron; Brill, Elizabeth; Tsuji, Yukiko; Ralph, John; Dennis, Elizabeth S; Llewellyn, Danny; Pettolino, Filomena A

    2017-07-18

    Knowledge of plant secondary cell wall (SCW) regulation and deposition is mainly based on the Arabidopsis model of a 'typical' lignocellulosic SCW. However, SCWs in other plants can vary from this. The SCW of mature cotton seed fibres is highly cellulosic and lacks lignification whereas xylem SCWs are lignocellulosic. We used cotton as a model to study different SCWs and the expression of the genes involved in their formation via RNA deep sequencing and chemical analysis of stem and seed fibre. Transcriptome comparisons from cotton xylem and pith as well as from a developmental series of seed fibres revealed tissue-specific and developmentally regulated expression of several NAC transcription factors some of which are likely to be important as top tier regulators of SCW formation in xylem and/or seed fibre. A so far undescribed hierarchy was identified between the top tier NAC transcription factors SND1-like and NST1/2 in cotton. Key SCW MYB transcription factors, homologs of Arabidopsis MYB46/83, were practically absent in cotton stem xylem. Lack of expression of other lignin-specific MYBs in seed fibre relative to xylem could account for the lack of lignin deposition in seed fibre. Expression of a MYB103 homolog correlated with temporal expression of SCW CesAs and cellulose synthesis in seed fibres. FLAs were highly expressed and may be important structural components of seed fibre SCWs. Finally, we made the unexpected observation that cell walls in the pith of cotton stems contained lignin and had a higher S:G ratio than in xylem, despite that tissue's lacking many of the gene transcripts normally associated with lignin biosynthesis. Our study in cotton confirmed some features of the currently accepted gene regulatory cascade for 'typical' plant SCWs, but also revealed substantial differences, especially with key downstream NACs and MYBs. The lignocellulosic SCW of cotton xylem appears to be achieved differently from that in Arabidopsis. Pith cell walls in

  14. On-Off Switches for Secondary Cell Wall Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Huan-Zhong Wang; Richard A.Dixon

    2012-01-01

    Secondary cell walls provide plants with rigidity and strength to support their body weight and ensure water and nutrient transport.They also provide textiles,timber,and potentially second-generation biofuels for human use.Genes responsible for synthesis of the different cell wall components,namely cellulose,hemicelluloses,and lignin,are coordinately expressed and under transcriptional regulation.In the past several years,cell wall-related NAC and MYB transcription factors have been intensively investigated in different species and shown to be master switches of secondary cell wall biosynthesis.Positive and negative regulators,which function upstream of NAC master switches,have also been identified in different plant tissues.Further elucidation of the regulatory mechanisms of cell wall synthesis will facilitate the engineering of plant feedstocks suitable for biofuel production.

  15. The dynamic interplay of plasma membrane domains and cortical microtubules in secondary cell wall patterning

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    Yoshihisa eOda

    2013-12-01

    Full Text Available Patterning of the cellulosic cell wall underlies the shape and function of plant cells. The cortical microtubule array plays a central role in the regulation of cell wall patterns. However, the regulatory mechanisms by which secondary cell wall patterns are established through cortical microtubules remain to be fully determined. Our recent study in xylem vessel cells revealed that a mutual inhibitory interaction between cortical microtubules and distinct plasma membrane domains leads to distinctive patterning in secondary cell walls. Our research revealed that the recycling of active and inactive ROP proteins by a specific GAP and GEF pair establishes distinct de novo plasma membrane domains. Active ROP recruits a plant-specific microtubule-associated protein, MIDD1, which mediates the mutual interaction between cortical microtubules and plasma membrane domains. In this mini review, we summarize recent research regarding secondary wall patterning, with a focus on the emerging interplay between plasma membrane domains and cortical microtubules through MIDD1 and ROP.

  16. Molecular regulation of plant cell wall extensibility

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    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  17. NPPs Secondary Circuit Piping Wall-Thinning Management in China

    International Nuclear Information System (INIS)

    Zhong Zhimin; Li Jinsong; Zheng Hui

    2012-01-01

    Since 1980s, secondary circuit piping wall-thinning incidents happened in nuclear power plants (NPPs) worldwide. Particularly Surry 2 and Mihama 3 accidents resulted from flow-accelerated corrosion (FAC), unplanned outage, huge fatalities and economic loss pushed whole industry to pay more attention on the wall-thinning problem.

  18. Overexpression of SbMyb60 impacts phenylpropanoid biosynthesis and alters secondary cell wall composition in sorghum bicolor

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    The phenylpropanoid biosynthesis pathway that generates lignin subunits represents a significant target to alter the abundance and composition of lignin. The major regulators of phenylpropanoid metabolism are myb transcription factors, which have been shown to modulate secondary cell wall compositi...

  19. Concrete as secondary containment for interior wall embedded waste lines

    International Nuclear Information System (INIS)

    Porter, C.L.

    1993-01-01

    Throughout the Department of Energy (DOE) complex are numerous facilities that handle hazardous waste solutions. Secondary containment of tank systems and their ancillary piping is a major concern for existing facilities. The Idaho Division of Environmental Quality was petitioned in 1990 for an Equivalent Device determination regarding secondary containment of waste lines embedded in interior concrete walls. The petition was granted, however it expires in 1996. To address the secondary containment issue, additional studies were undertaken. One study verified the hypothesis that an interior wall pipe leak would follow the path of least resistance through the naturally occurring void found below a rigidly supported pipe and pass into an adjacent room where detection could occur, before any significant deterioration of the concrete takes place. Other tests demonstrated that with acidic waste solutions rebar and cold joints are not an accelerated path to the environment. The results from these latest studies confirm that the subject configuration meets all the requirements of secondary containment

  20. Stabilization of thin shell modes by a rotating secondary wall

    International Nuclear Information System (INIS)

    Gimblett, C.G.

    1989-01-01

    A simple model is developed to investigate if and under what circumstances the thin shell instabilities of a Reverse Field Pinch can be stabilized by a rotating secondary wall. The principles may be applicable to reactor designs that utilize a flowing liquid blanket (author)

  1. The poplar MYB master switches bind to the SMRE site and activate the secondary wall biosynthetic program during wood formation.

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    Ruiqin Zhong

    Full Text Available Wood is mainly composed of secondary walls, which constitute the most abundant stored carbon produced by vascular plants. Understanding the molecular mechanisms controlling secondary wall deposition during wood formation is not only an important issue in plant biology but also critical for providing molecular tools to custom-design wood composition suited for diverse end uses. Past molecular and genetic studies have revealed a transcriptional network encompassing a group of wood-associated NAC and MYB transcription factors that are involved in the regulation of the secondary wall biosynthetic program during wood formation in poplar trees. Here, we report the functional characterization of poplar orthologs of MYB46 and MYB83 that are known to be master switches of secondary wall biosynthesis in Arabidopsis. In addition to the two previously-described PtrMYB3 and PtrMYB20, two other MYBs, PtrMYB2 and PtrMYB21, were shown to be MYB46/MYB83 orthologs by complementation and overexpression studies in Arabidopsis. The functional roles of these PtrMYBs in regulating secondary wall biosynthesis were further demonstrated in transgenic poplar plants showing an ectopic deposition of secondary walls in PtrMYB overexpressors and a reduction of secondary wall thickening in their dominant repressors. Furthermore, PtrMYB2/3/20/21 together with two other tree MYBs, the Eucalyptus EgMYB2 and the pine PtMYB4, were shown to differentially bind to and activate the eight variants of the 7-bp SMRE consensus sequence, composed of ACC(A/TA(A/C(T/C. Together, our results indicate that the tree MYBs, PtrMYB2/3/20/21, EgMYB2 and PtMYB4, are master transcriptional switches that activate the SMRE sites in the promoters of target genes and thereby regulate secondary wall biosynthesis during wood formation.

  2. Cellulose-hemicellulose interaction in wood secondary cell-wall

    International Nuclear Information System (INIS)

    Zhang, Ning; Li, Shi; Hong, Yu; Chen, Youping; Xiong, Liming

    2015-01-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose. (paper)

  3. Cellulose-hemicellulose interaction in wood secondary cell-wall

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    Zhang, Ning; Li, Shi; Xiong, Liming; Hong, Yu; Chen, Youping

    2015-12-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose.

  4. Primary Metabolism during Biosynthesis of Secondary Wall Polymers of Protoxylem Vessel Elements1[OPEN

    Science.gov (United States)

    Morisaki, Keiko; Sawada, Yuji; Sano, Ryosuke; Yamamoto, Atsushi; Kurata, Tetsuya; Suzuki, Shiro; Matsuda, Mami; Hasunuma, Tomohisa; Hirai, Masami Yokota

    2016-01-01

    Xylem vessels, the water-conducting cells in vascular plants, undergo characteristic secondary wall deposition and programmed cell death. These processes are regulated by the VASCULAR-RELATED NAC-DOMAIN (VND) transcription factors. Here, to identify changes in metabolism that occur during protoxylem vessel element differentiation, we subjected tobacco (Nicotiana tabacum) BY-2 suspension culture cells carrying an inducible VND7 system to liquid chromatography-mass spectrometry-based wide-target metabolome analysis and transcriptome analysis. Time-course data for 128 metabolites showed dynamic changes in metabolites related to amino acid biosynthesis. The concentration of glyceraldehyde 3-phosphate, an important intermediate of the glycolysis pathway, immediately decreased in the initial stages of cell differentiation. As cell differentiation progressed, specific amino acids accumulated, including the shikimate-related amino acids and the translocatable nitrogen-rich amino acid arginine. Transcriptome data indicated that cell differentiation involved the active up-regulation of genes encoding the enzymes catalyzing fructose 6-phosphate biosynthesis from glyceraldehyde 3-phosphate, phosphoenolpyruvate biosynthesis from oxaloacetate, and phenylalanine biosynthesis, which includes shikimate pathway enzymes. Concomitantly, active changes in the amount of fructose 6-phosphate and phosphoenolpyruvate were detected during cell differentiation. Taken together, our results show that protoxylem vessel element differentiation is associated with changes in primary metabolism, which could facilitate the production of polysaccharides and lignin monomers and, thus, promote the formation of the secondary cell wall. Also, these metabolic shifts correlate with the active transcriptional regulation of specific enzyme genes. Therefore, our observations indicate that primary metabolism is actively regulated during protoxylem vessel element differentiation to alter the cell’s metabolic

  5. The adventitia: essential regulator of vascular wall structure and function.

    Science.gov (United States)

    Stenmark, Kurt R; Yeager, Michael E; El Kasmi, Karim C; Nozik-Grayck, Eva; Gerasimovskaya, Evgenia V; Li, Min; Riddle, Suzette R; Frid, Maria G

    2013-01-01

    The vascular adventitia acts as a biological processing center for the retrieval, integration, storage, and release of key regulators of vessel wall function. It is the most complex compartment of the vessel wall and is composed of a variety of cells, including fibroblasts, immunomodulatory cells (dendritic cells and macrophages), progenitor cells, vasa vasorum endothelial cells and pericytes, and adrenergic nerves. In response to vascular stress or injury, resident adventitial cells are often the first to be activated and reprogrammed to influence the tone and structure of the vessel wall; to initiate and perpetuate chronic vascular inflammation; and to stimulate expansion of the vasa vasorum, which can act as a conduit for continued inflammatory and progenitor cell delivery to the vessel wall. This review presents the current evidence demonstrating that the adventitia acts as a key regulator of vascular wall function and structure from the outside in.

  6. Traumatic abdominal wall hernia secondary to motorcycle handle bar injury

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    R S Jamabo

    2011-01-01

    Conclusion: We recommend a high level of clinical suspicion for traumatic abdominal wall herniation in all patients with traumatic abdominal wall injuries. It is instructive that the area be explored with primary repair of the hernia and other tissue planes of the abdominal wall.

  7. Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

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    Levin, David E.

    2011-01-01

    The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to the Rho1 GTPase, which mobilizes a physiologic response through a variety of effectors. Activation of CWI signaling regulates the production of various carbohydrate polymers of the cell wall, as well as their polarized delivery to the site of cell wall remodeling. This review article centers on CWI signaling in Saccharomyces cerevisiae through the cell cycle and in response to cell wall stress. The interface of this signaling pathway with other pathways that contribute to the maintenance of cell wall integrity is also discussed. PMID:22174182

  8. Effect of Compliant Walls on Secondary Instabilities in Boundary-Layer Transition

    Science.gov (United States)

    Joslin, Ronald D.; Morris, Philip J.

    1991-01-01

    For aerodynamic and hydrodynamic vehicles, it is highly desirable to reduce drag and noise levels. A reduction in drag leads to fuel savings. In particular for submersible vehicles, a decrease in noise levels inhibits detection. A suggested means to obtain these reduction goals is by delaying the transition from laminar to turbulent flow in external boundary layers. For hydrodynamic applications, a passive device which shows promise for transition delays is the compliant coating. In previous studies with a simple mechanical model representing the compliant wall, coatings were found that provided transition delays as predicted from the semi-empirical e(sup n) method. Those studies were concerned with the linear stage of transition where the instability of concern is referred to as the primary instability. For the flat-plate boundary layer, the Tollmien-Schlichting (TS) wave is the primary instability. In one of those studies, it was shown that three-dimensional (3-D) primary instabilities, or oblique waves, could dominate transition over the coatings considered. From the primary instability, the stretching and tilting of vorticity in the shear flow leads to a secondary instability mechanism. This has been theoretical described by Herbert based on Floquet theory. In the present study, Herbert's theory is used to predict the development of secondary instabilities over isotropic and non-isotropic compliant walls. Since oblique waves may be dominant over compliant walls, a secondary theory extention is made to allow for these 3-D primary instabilities. The effect of variations in primary amplitude, spanwise wavenumber, and Reynolds number on the secondary instabilities are examined. As in the rigid wall case, over compliant walls the subharmonic mode of secondary instability dominates for low-amplitude primary disturbances. Both isotropic and non-isotropic compliant walls lead to reduced secondary growth rates compared to the rigid wall results. For high frequencies

  9. Gibberellin overproduction promotes sucrose synthase expression and secondary cell wall deposition in cotton fibers.

    Directory of Open Access Journals (Sweden)

    Wen-Qin Bai

    Full Text Available Bioactive gibberellins (GAs comprise an important class of natural plant growth regulators and play essential roles in cotton fiber development. To date, the molecular base of GAs' functions in fiber development is largely unclear. To address this question, the endogenous bioactive GA levels in cotton developing fibers were elevated by specifically up-regulating GA 20-oxidase and suppressing GA 2-oxidase via transgenic methods. Higher GA levels in transgenic cotton fibers significantly increased micronaire values, 1000-fiber weight, cell wall thickness and cellulose contents of mature fibers. Quantitative RT-PCR and biochemical analysis revealed that the transcription of sucrose synthase gene GhSusA1 and sucrose synthase activities were significantly enhanced in GA overproducing transgenic fibers, compared to the wild-type cotton. In addition, exogenous application of bioactive GA could promote GhSusA1 expression in cultured fibers, as well as in cotton hypocotyls. Our results suggested that bioactive GAs promoted secondary cell wall deposition in cotton fibers by enhancing sucrose synthase expression.

  10. Developmental characteristics of parenchyma and fiber cells and their secondary wall deposition in fargesia yunnanensis

    International Nuclear Information System (INIS)

    Wang, S.G.; Zhan, H.; Wan, C.B.; Lin, S.Y.

    2017-01-01

    The aim of this study is to describe and analyse the morphological characteristics of nuclei and the secondary wall deposition in parenchyma and fiber cells during the whole bamboo growth cycle from shoots to old culms, with a further purpose to assess the developmental differences between fibers and parenchyma cells and analyze the secondary wall deposition mechanism. Initially the fiber wall thickness was less than the parenchyma cell thickness in young shoots, but increased significantly after 1 year. Fibers elongated earlier than both their nuclei and parenchyma cells. Fiber nuclei also elongated and presented the spindle shape in longitudinal section. The formation and elongation of long cells were involved in the fast elongation of internodes. In mature culms, the ways of secondary wall deposition for fibers depended on their diameter and positions. Large diameter fibers usually had more cell wall layers than narrow fibers. (author)

  11. Secondary cell wall formation in Cryptococcus neoformans as a rescue mechanism against acid-induced autolysis.

    Science.gov (United States)

    Farkas, Vladimír; Takeo, Kanji; Maceková, Danka; Ohkusu, Misako; Yoshida, Soichi; Sipiczki, Matthias

    2009-03-01

    Growth of the opportunistic yeast pathogen Cryptococcus neoformans in a synthetic medium containing yeast nitrogen base and 1.0-3.0% glucose is accompanied by spontaneous acidification of the medium, with its pH decreasing from the initial 5.5 to around 2.5 in the stationary phase. During the transition from the late exponential to the stationary phase of growth, many cells died as a consequence of autolytic erosion of their cell walls. Simultaneously, there was an increase in an ecto-glucanase active towards beta-1,3-glucan and having a pH optimum between pH 3.0 and 3.5. As a response to cell wall degradation, some cells developed an unusual survival strategy by forming 'secondary' cell walls underneath the original ones. Electron microscopy revealed that the secondary cell walls were thicker than the primary ones, exposing bundles of polysaccharide microfibrils only partially masked by an amorphous cell wall matrix on their surfaces. The cells bearing secondary cell walls had a three to five times higher content of the alkali-insoluble cell wall polysaccharides glucan and chitin, and their chitin/glucan ratio was about twofold higher than in cells from the logarithmic phase of growth. The cell lysis and the formation of the secondary cell walls could be suppressed by buffering the growth medium between pH 4.5 and 6.5.

  12. Formation of wood secondary cell wall may involve two type cellulose synthase complexes in Populus.

    Science.gov (United States)

    Xi, Wang; Song, Dongliang; Sun, Jiayan; Shen, Junhui; Li, Laigeng

    2017-03-01

    Cellulose biosynthesis is mediated by cellulose synthases (CesAs), which constitute into rosette-like cellulose synthase complexe (CSC) on the plasma membrane. Two types of CSCs in Arabidopsis are believed to be involved in cellulose synthesis in the primary cell wall and secondary cell walls, respectively. In this work, we found that the two type CSCs participated cellulose biosynthesis in differentiating xylem cells undergoing secondary cell wall thickening in Populus. During the cell wall thickening process, expression of one type CSC genes increased while expression of the other type CSC genes decreased. Suppression of different type CSC genes both affected the wall-thickening and disrupted the multilaminar structure of the secondary cell walls. When CesA7A was suppressed, crystalline cellulose content was reduced, which, however, showed an increase when CesA3D was suppressed. The CesA suppression also affected cellulose digestibility of the wood cell walls. The results suggest that two type CSCs are involved in coordinating the cellulose biosynthesis in formation of the multilaminar structure in Populus wood secondary cell walls.

  13. Cellular growth in plants requires regulation of cell wall biochemistry.

    Science.gov (United States)

    Chebli, Youssef; Geitmann, Anja

    2017-02-01

    Cell and organ morphogenesis in plants are regulated by the chemical structure and mechanical properties of the extracellular matrix, the cell wall. The two primary load bearing components in the plant cell wall, the pectin matrix and the cellulose/xyloglucan network, are constantly remodelled to generate the morphological changes required during plant development. This remodelling is regulated by a plethora of loosening and stiffening agents such as pectin methyl-esterases, calcium ions, expansins, and glucanases. The tight spatio-temporal regulation of the activities of these agents is a sine qua non condition for proper morphogenesis at cell and tissue levels. The pectin matrix and the cellulose-xyloglucan network operate in concert and their behaviour is mutually dependent on their chemical, structural and mechanical modifications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A Transcriptomic Analysis of Xylan Mutants Does Not Support the Existence of a Secondary Cell Wall Integrity System in Arabidopsis.

    Science.gov (United States)

    Faria-Blanc, Nuno; Mortimer, Jenny C; Dupree, Paul

    2018-01-01

    Yeast have long been known to possess a cell wall integrity (CWI) system, and recently an analogous system has been described for the primary walls of plants (PCWI) that leads to changes in plant growth and cell wall composition. A similar system has been proposed to exist for secondary cell walls (SCWI). However, there is little data to support this. Here, we analyzed the stem transcriptome of a set of cell wall biosynthetic mutants in order to investigate whether cell wall damage, in this case caused by aberrant xylan synthesis, activates a signaling cascade or changes in cell wall synthesis gene expression. Our data revealed remarkably few changes to the transcriptome. We hypothesize that this is because cells undergoing secondary cell wall thickening have entered a committed programme leading to cell death, and therefore a SCWI system would have limited impact. The absence of transcriptomic responses to secondary cell wall alterations may facilitate engineering of the secondary cell wall of plants.

  15. BRITTLE CULM16 (BRITTLE NODE) is required for the formation of secondary cell walls in rice nodes

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; WANG Jiu-lin; GUO Xiu-ping; ZHANG Xin; LEI Cai-lin; CHENG Zhi-jun; WAN Jian-min; REN Yu-long; CHEN Sai-hua; XU Yang; ZHOU Kun-neng; ZHANG Long; MING Ming; WU Fu-qing; LIN Qi-bing

    2017-01-01

    Plant cell walls constitute the skeletal structures of plant bodies, and thus confer lodging resistance for grain crops. While the basic cell wall synthesis machinery is relatively well established now, our understanding of how the process is regulated remains limited and fragmented. In this study, we report the identification and characterization of the novel rice (Oryza sativa L.) brittle culm16 (brittle node; bc16) mutant. The brittle node phenotype of the bc16 mutant appears exclusively at nodes, and resembles the previously reported bc5 mutant. Combined histochemical staining and electron microscopy assays revealed that in the bc16 mutant, the secondary cell wall formation and thickening of node sclerenchyma tissues are seriously affected after heading. Furthermore, cell wall composition assays revealed that the bc16 mutation led to a significant reduction in cellulose and lignin contents. Using a map-based cloning approach, the bc16 locus is mapped to an approximately 1.7-Mb region of chromosome 4. Together, our findings strengthen evidence for discretely spatial differences in the secondary cell wall formation within plant bodies.

  16. A synthetic auxin (NAA) suppresses secondary wall cellulose synthesis and enhances elongation in cultured cotton fiber.

    Science.gov (United States)

    Singh, Bir; Cheek, Hannah D; Haigler, Candace H

    2009-07-01

    Use of a synthetic auxin (naphthalene-1-acetic acid, NAA) to start (Gossypium hirsutum) ovule/fiber cultures hindered fiber secondary wall cellulose synthesis compared with natural auxin (indole-3-acetic acid, IAA). In contrast, NAA promoted fiber elongation and ovule weight gain, which resulted in larger ovule/fiber units. To reach these conclusions, fiber and ovule growth parameters were measured and cell wall characteristics were examined microscopically. The differences in fiber from NAA and IAA culture were underpinned by changes in the expression patterns of marker genes for three fiber developmental stages (elongation, the transition stage, and secondary wall deposition), and these gene expression patterns were also analyzed quantitatively in plant-grown fiber. The results demonstrate that secondary wall cellulose synthesis: (1) is under strong transcriptional control that is influenced by auxin; and (2) must be specifically characterized in the cotton ovule/fiber culture system given the many protocol variables employed in different laboratories.

  17. Subclavian vein aneurysm secondary to a benign vessel wall hamartoma

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Patrick [Nationwide Children' s Hospital, Section of Pediatric Interventional Radiology, Columbus, OH (United States); Spaeth, Maya [Nationwide Children' s Hospital, Section of Plastic and Reconstructive Surgery, Columbus, OH (United States); Prasad, Vinay [Nationwide Children' s Hospital, Section of Pediatric Pathology, Columbus, OH (United States); McConnell, Patrick [Nationwide Children' s Hospital, Section of Cardiothoracic Surgery, Columbus, OH (United States)

    2013-11-15

    Venous aneurysms are rare clinical entities, particularly in children, and their presentation and natural history often depend on the anatomical location and underlying etiology. We present a single case of a 12-year-old girl who presented with a palpable right supraclavicular mass. Imaging evaluation with CT, conventional venography, MRI and sonography revealed a large fusiform subclavian vein aneurysm with an unusual, mass-like fibrofatty component incorporated into the vessel wall. The girl ultimately required complete resection of the right subclavian vein with placement of a synthetic interposition graft. This case provides a radiology/pathology correlation of an entity that has not previously been described as well as an example of the utility of multiple imaging modalities to aid diagnosis and preoperative planning. (orig.)

  18. In-situ Raman microprobe studies of plant cell walls: macromolecular organization and compositional variability in the secondary wall of Picea mariana (Mill.) B.S.P.

    Science.gov (United States)

    U.P. Agarwal; R.H. Atalla

    1986-01-01

    Native-state organization and distribution of cell-wall components in the secondary wall of woody tissue from P. mariana (Black Spruce) have been investigated using polarized Raman microspectroscopy. Evidence for orientation is detected through Raman intensity variations resulting from rotations of the exciting electric vector with respect to cell-wall geometry....

  19. Nuclear Power Plants Secondary Circuit Piping Wall-Thinning Management in China

    International Nuclear Information System (INIS)

    Zhong Zhimin; Li Jinsong; Zheng Hui

    2012-01-01

    Research and field feedbacks showed that nuclear power plants secondary circuit steam and water piping are more sensitive than that of fuel plant to the attack of flow-accelerated corrosion (FAC). FAC, Liquid droplet impingement or cavitation erosion will cause secondary circuit piping local wall-thinning in NPPs. Without effective management, the wall-thinning in those high energy piping will cause leakage or pipe rupture during nuclear power plant operation, more seriously cause unplanned shut down, injured and fatality, or heavy economic losses. This paper briefly introduces the history, development and state of the art of secondary circuit piping wall-thinning management in China NPPs. Then, the effectiveness of inspection grid size selecting was analyzed in detail based on field feedbacks. EPRI recommendatory inspection grid, JSME code recommendatory grid and plant specific inspection grid were compared and the detection probabilities of local wall-thinning were estimated. Then, the development and application of NPPs Secondary Circuit Piping Wall Thickness Management Information System, developed, operated and maintained by our team, was briefly introduced and the statistical analysis results of 11 PWR units were shared. It was conclude that the long term, systemic, effective wall-thinning management strategy of high energy piping was very important to the safety and economic operation of NPPs. Furthermore, take into account the actual situation of China nuclear power plants, some advice and suggestion on developing effective nuclear power plant secondary circuit steam and water piping wall-thinning management system are put forward from code development, design and manufacture, operation management, pipeline and locations selection, inspection method selection and application, thickness measurement result evaluation, residual life predication and decision making, feedbacks usage, personnel training and etc. (author)

  20. Exogenous GA3 Application Enhances Xylem Development and Induces the Expression of Secondary Wall Biosynthesis Related Genes in Betula platyphylla

    Directory of Open Access Journals (Sweden)

    Huiyan Guo

    2015-09-01

    Full Text Available Gibberellin (GA is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla (birch seeds were treated with 300 ppm GA3 and/or 300 ppm paclobutrazol (PAC, seed germination was recorded, and transverse sections of hypocotyls were stained with toluidine blue; the two-month-old seedlings were treated with 50 μM GA3 and/or 50 μM PAC, transverse sections of seedling stems were stained using phloroglucinol–HCl, and secondary wall biosynthesis related genes expression was analyzed by real-time quantitative PCR. Results indicated that germination percentage, energy and time of seeds, hypocotyl height and seedling fresh weight were enhanced by GA3, and reduced by PAC; the xylem development was wider in GA3-treated plants than in the control; the expression of NAC and MYB transcription factors, CESA, PAL, and GA oxidase was up-regulated during GA3 treatment, suggesting their role in GA3-induced xylem development in the birch. Our results suggest that GA3 induces the expression of secondary wall biosynthesis related genes to trigger xylogenesis in the birch plants.

  1. Nitrogen fertilizer application affects lodging resistance by altering secondary cell wall synthesis in japonica rice (Oryza sativa).

    Science.gov (United States)

    Zhang, Wujun; Wu, Longmei; Ding, Yanfeng; Yao, Xiong; Wu, Xiaoran; Weng, Fei; Li, Ganghua; Liu, Zhenghui; Tang, She; Ding, Chengqiang; Wang, Shaohua

    2017-09-01

    Stem mechanical strength is an important agricultural quantitative trait that is closely related to lodging resistance in rice, which is known to be reduced by fertilizer with higher levels of nitrogen. To understand the mechanism that regulates stem mechanical strength in response to nitrogen, we analysed stem morphology, anatomy, mechanical properties, cell wall components, and expression of cell wall-related genes, in two varieties of japonica rice, namely, Wuyunjing23 (lodging-resistant variety) and W3668 (lodging-susceptible variety). The results showed that higher nitrogen fertilizer increased the lodging index in both varieties due to a reduction in breaking strength and bending stress, and these changes were larger in W3668. Cellulose content decreased slightly under higher nitrogen fertilizer, whereas lignin content reduced remarkably. Histochemical staining revealed that high nitrogen application decreased lignin deposition in the secondary cell wall of the sclerenchyma cells and vascular bundle cells compared with the low nitrogen treatments, while it did not alter the pattern of cellulose deposition in these cells in both Wuyunjing23 and W3668. In addition, the expression of the genes involved in lignin biosynthesis, OsPAL, OsCoMT, Os4CL3, OsCCR, OsCAD2, OsCAD7, OsCesA4, and OsCesA7, were also down-regulated under higher nitrogen conditions at the early stage of culm growth. These results suggest that the genes involved in lignin biosynthesis are down-regulated by higher nitrogen fertilizer, which causes lignin deficiency in the secondary cell walls and the weakening of mechanical tissue structure. Subsequently, this results in these internodes with reduced mechanical strength and poor lodging resistance.

  2. Development of secondary cell wall in cotton fibers as examined with Fourier transform-infrared spectroscopy

    Science.gov (United States)

    Our presentation will focus on continuing efforts to examine secondary cell wall development in cotton fibers using infrared Spectroscopy. Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-...

  3. Regulator of calcineurin 1 mediates pathological vascular wall remodeling

    Science.gov (United States)

    Esteban, Vanesa; Méndez-Barbero, Nerea; Jesús Jiménez-Borreguero, Luis; Roqué, Mercè; Novensá, Laura; Belén García-Redondo, Ana; Salaices, Mercedes; Vila, Luis; Arbonés, María L.

    2011-01-01

    Artery wall remodeling, a major feature of diseases such as hypertension, restenosis, atherosclerosis, and aneurysm, involves changes in the tunica media mass that reduce or increase the vessel lumen. The identification of molecules involved in vessel remodeling could aid the development of improved treatments for these pathologies. Angiotensin II (AngII) is a key effector of aortic wall remodeling that contributes to aneurysm formation and restenosis through incompletely defined signaling pathways. We show that AngII induces vascular smooth muscle cell (VSMC) migration and vessel remodeling in mouse models of restenosis and aneurysm. These effects were prevented by pharmacological inhibition of calcineurin (CN) or lentiviral delivery of CN-inhibitory peptides. Whole-genome analysis revealed >1,500 AngII-regulated genes in VSMCs, with just 11 of them requiring CN activation. Of these, the most sensitive to CN activation was regulator of CN 1 (Rcan1). Rcan1 was strongly activated by AngII in vitro and in vivo and was required for AngII-induced VSMC migration. Remarkably, Rcan1−/− mice were resistant to AngII-induced aneurysm and restenosis. Our results indicate that aneurysm formation and restenosis share mechanistic elements and identify Rcan1 as a potential therapeutic target for prevention of aneurysm and restenosis progression. PMID:21930771

  4. Jasmonate-responsive transcription factors regulating plant secondary metabolism.

    Science.gov (United States)

    Zhou, Meiliang; Memelink, Johan

    2016-01-01

    Plants produce a large variety of secondary metabolites including alkaloids, glucosinolates, terpenoids and phenylpropanoids. These compounds play key roles in plant-environment interactions and many of them have pharmacological activity in humans. Jasmonates (JAs) are plant hormones which induce biosynthesis of many secondary metabolites. JAs-responsive transcription factors (TFs) that regulate the JAs-induced accumulation of secondary metabolites belong to different families including AP2/ERF, bHLH, MYB and WRKY. Here, we give an overview of the types and functions of TFs that have been identified in JAs-induced secondary metabolite biosynthesis, and highlight their similarities and differences in regulating various biosynthetic pathways. We review major recent developments regarding JAs-responsive TFs mediating secondary metabolite biosynthesis, and provide suggestions for further studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Impairment of Cellulose Synthases Required for Arabidopsis Secondary Cell Wall Formation Enhances Disease Resistance[W

    Science.gov (United States)

    Hernández-Blanco, Camilo; Feng, Dong Xin; Hu, Jian; Sánchez-Vallet, Andrea; Deslandes, Laurent; Llorente, Francisco; Berrocal-Lobo, Marta; Keller, Harald; Barlet, Xavier; Sánchez-Rodríguez, Clara; Anderson, Lisa K.; Somerville, Shauna; Marco, Yves; Molina, Antonio

    2007-01-01

    Cellulose is synthesized by cellulose synthases (CESAs) contained in plasma membrane–localized complexes. In Arabidopsis thaliana, three types of CESA subunits (CESA4/IRREGULAR XYLEM5 [IRX5], CESA7/IRX3, and CESA8/IRX1) are required for secondary cell wall formation. We report that mutations in these proteins conferred enhanced resistance to the soil-borne bacterium Ralstonia solanacearum and the necrotrophic fungus Plectosphaerella cucumerina. By contrast, susceptibility to these pathogens was not altered in cell wall mutants of primary wall CESA subunits (CESA1, CESA3/ISOXABEN RESISTANT1 [IXR1], and CESA6/IXR2) or POWDERY MILDEW–RESISTANT5 (PMR5) and PMR6 genes. Double mutants indicated that irx-mediated resistance was independent of salicylic acid, ethylene, and jasmonate signaling. Comparative transcriptomic analyses identified a set of common irx upregulated genes, including a number of abscisic acid (ABA)–responsive, defense-related genes encoding antibiotic peptides and enzymes involved in the synthesis and activation of antimicrobial secondary metabolites. These data as well as the increased susceptibility of ABA mutants (abi1-1, abi2-1, and aba1-6) to R. solanacearum support a direct role of ABA in resistance to this pathogen. Our results also indicate that alteration of secondary cell wall integrity by inhibiting cellulose synthesis leads to specific activation of novel defense pathways that contribute to the generation of an antimicrobial-enriched environment hostile to pathogens. PMID:17351116

  6. Investigation of secondary flows in turbulent pipe flows with three-dimensional sinusoidal walls

    Science.gov (United States)

    Chan, Leon; MacDonald, Michael; Chung, Daniel; Hutchins, Nicholas; Ooi, Andrew

    2017-11-01

    The occurrence of secondary flows is systematically investigated via Direct Numerical Simulations (DNS) of turbulent flow in a rough wall pipe at friction Reynolds numbers of 540. In this study, the peak-to-trough height of the roughness elements, which consist of three-dimensional sinusoidal roughness, is fixed at 120 viscous units while the wavelength of the roughness elements is varied. The solidity or effective slope (ES) of the roughness ranges from the sparse regime (ES = 0.18) to the closely packed roughness/dense regime (ES = 0.72). The time-independent dispersive stresses, which arise due to the stationary features of the flow, are analysed and are found to increase with increasing roughness wavelength. These dispersive stresses are related to the occurrence of secondary flows and are maximum within the roughness canopy. Above the crest of the roughness elements, the dispersive stresses reduce to zero at wall-normal heights greater than half of the roughness wavelength. This study has found that the size and wall-normal extent of the secondary flows scales with the roughness wavelength and can reach wall-normal heights of almost half of the pipe radius.

  7. Studying secondary growth and bast fiber development: the hemp hypocotyl peeks behind the wall

    Directory of Open Access Journals (Sweden)

    Marc Behr

    2016-11-01

    Full Text Available Cannabis sativa L. is an annual herbaceous crop grown for the production of long extraxylary fibers, the bast fibers, rich in cellulose and used both in the textile and biocomposite sectors. Despite being herbaceous, hemp undergoes secondary growth and this is well exemplified by the hypocotyl. The hypocotyl was already shown to be a suitable model to study secondary growth in other herbaceous species, namely Arabidopsis thaliana and it shows an important practical advantage, i.e. elongation and radial thickening are temporally separated. This study focuses on the mechanisms marking the transition from primary to secondary growth in the hemp hypocotyl by analysing the suite of events accompanying vascular tissue and bast fiber development. Transcriptomics, imaging and quantification of phytohormones were carried out on four representative developmental stages (i.e. 6-9-15-20 days after sowing to provide a comprehensive overview of the events associated with primary and secondary growth in hemp. This multidisciplinary approach provides cell wall-related snapshots of the growing hemp hypocotyl and identifies marker genes associated with the young (expansins, β-galactosidases and transcription factors involved in light-related processes and the older hypocotyl (secondary cell wall biosynthetic genes and transcription factors.

  8. On Secondary Control Approaches for Voltage Regulation in DC Microgrids

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Davari, Pooya

    2017-01-01

    Centralized or decentralized secondary controller is commonly employed to regulate the voltage drop raised by the primary controller. However, in the case of high capacity MGs and long feeders with much voltage drop on the line resistances, the conventional methods may not guarantee the voltage r...

  9. On Secondary Control Approaches for Voltage Regulation in DC Microgrids

    DEFF Research Database (Denmark)

    Peyghami Akhuleh, Saeed; Mokhtari, Hossein; Davari, Pooya

    2017-01-01

    Centralized or decentralized secondary controller is commonly employed to regulate the voltage drop raised by the primary controller. However, in the case of high capacity MGs and long feeders with much voltage drop on the line resistances, the conventional methods may not guarantee the voltage...

  10. Approaches to link RNA secondary structures with splicing regulation

    DEFF Research Database (Denmark)

    Plass, Mireya; Eyras, Eduardo

    2014-01-01

    In higher eukaryotes, alternative splicing is usually regulated by protein factors, which bind to the pre-mRNA and affect the recognition of splicing signals. There is recent evidence that the secondary structure of the pre-mRNA may also play an important role in this process, either by facilitat...... describes the steps in the analysis of the secondary structure of the pre-mRNA and its possible relation to splicing. As a working example, we use the case of yeast and the problem of the recognition of the 3' splice site (3'ss).......In higher eukaryotes, alternative splicing is usually regulated by protein factors, which bind to the pre-mRNA and affect the recognition of splicing signals. There is recent evidence that the secondary structure of the pre-mRNA may also play an important role in this process, either...

  11. Means of regulating combustible materials and products in external walls

    Directory of Open Access Journals (Sweden)

    Mikkola Esko

    2016-01-01

    Full Text Available This report presents proposals for defining means of regulating the use of combustible materials and products in external walls. Required protections are based on the quantities of fire loads and their contribution to fire development. The study is based on life safety and protection of property priorities taking into account reaction to fire classes related to different types of fire loads and fire compartmentation requirements of the adjacent spaces of concern. The proposals include the following main principles in relation to fire-separation requirements: In case of internal fire exposure the protective structure for combustible building parts needs to meet at least half of the fire-separating requirement for the compartment of concern. In case of external fire exposure the protection time requirement can be 15 minutes less than for the internal protection. The proposals are applicable for residential buildings and offices. In case of buildings with longer evacuation times more stringent requirement levels may be considered. For verification of protection performance of fire loads it is proposed to use existing standardized test methods (fire protection ability (K classes and fire-separating function (EI classes validated methods of calculation and/or large scale fire testing.

  12. The cell wall and endoplasmic reticulum stress responses are coordinately regulated in Saccharomyces cerevisiae

    OpenAIRE

    Krysan, Damian J

    2009-01-01

    The unfolded protein response (UPR) is an intracellular signaling pathway that regulates the cellular response to the accumulation of misfolded proteins in eukaryotes. Our group has demonstrated that cell wall stress activates UPR in yeast through signals transmitted by the cell wall integrity (CWI) mitogen-activated protein (MAP) kinase cascade. The UPR is required to maintain cell wall integrity; mutants lacking a functional UPR have defects in cell wall biosynthesis and are hypersensitive ...

  13. Wall thinning trend analyses for secondary side piping of Korean NPPs

    International Nuclear Information System (INIS)

    Hwang, K.M.; Jin, T.E.; Lee, S.H.; Jeon, S.C.

    2003-01-01

    Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent the FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC have conducted a study for developing systematic FAC management technology for secondary side piping of all Korean nuclear power plants. As a part of the study, FAC analyses were performed using the CHECWORKS code. The analysis results were used to select components for inspection and to determine inspection intervals on each nuclear power plant. This paper describes the introduction of the FAC analysis method and the wall thinning trend analysis results by reactor type, system, and water treatment amine. This paper also represents the site application feasibility for secondary side piping management. The site application feasibility of the analysis results was proven by comparisons of predicted and measured wear rates. (author)

  14. Matching Electron Beams Without Secondary Collimation for Treatment of Extensive Recurrent Chest-Wall Carcinoma

    International Nuclear Information System (INIS)

    Feygelman, Vladimir; Mandelzweig, Yuri; Baral, Ed

    2015-01-01

    Matching electron beams without secondary collimators (applicators) were used for treatment of extensive, recurrent chest-wall carcinoma. Due to the wide penumbra of such beams, the homogeneity of the dose distribution at and around the junction point is clinically acceptable and relatively insensitive to positional errors. Specifically, dose around the junction point is homogeneous to within ±4% as calculated from beam profiles, while the positional error of 1 cm leaves this number essentially unchanged. The experimental isodose distribution in an anthropomorphic phantom supports this conclusion. Two electron beams with wide penumbra were used to cover the desired treatment area with satisfactory dose homogeneity. The technique is relatively simple yet clinically useful and can be considered a viable alternative for treatment of extensive chest-wall disease. The steps are suggested to make this technique more universal.

  15. Comparison and validation of Fourier transform infrared spectroscopic methods for monitoring secondary cell wall cellulose from cotton fibers

    Science.gov (United States)

    The amount of secondary cell wall (SCW) cellulose in the fiber affects the quality and commercial value of cotton. Accurate assessments of SCW cellulose are essential for improving cotton fibers. Fourier Transform Infrared (FT-IR) spectroscopy enables distinguishing SCW from other cell wall componen...

  16. A light controlled cavitand wall regulates guest binding.

    Science.gov (United States)

    Berryman, Orion B; Sather, Aaron C; Rebek, Julius

    2011-01-14

    Here we report a cavitand with a photochemical switch as one of the container walls. The azo-arene switch undergoes photoisomerization when subjected to UV light producing a self-fulfilled cavitand. This process is thermally and photochemically reversible. The reported cavitand binds small molecules and these guests can be ejected from the cavitand through this photochemical process.

  17. [Sinusotrabeculectomy with regulated filtration in the treatment of secondary glaucoma].

    Science.gov (United States)

    Barashkov, V I; Dushin, N V; Beliaev, V S; Kravchinina, V V; Gonchar, P A; Frolov, M A; Semin, S B

    1999-01-01

    A new method for surgical treatment of secondary glaucoma (neovascular, postuveal, traumatic, and aphakic) is described. The aims of the new method are as follows: regulation of ophthalmic tone in the postoperative period, pain relief, organ preservation, stabilization of the process, and creation of reliable routes of intraocular fluid discharge with formation of a stable diffuse functional pad. Seven patients (8 eyes) aged 13-70 years were operated on and followed up for up to 6 months. Preliminary results are presented. Positive shifts were observed in all cases.

  18. Analysis of Pipe Wall-thinning Caused by Water Chemistry Change in Secondary System of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hun; Hwang, Kyeongmo [KEPCO E and C, Gimcheon (Korea, Republic of); Moon, Seung-Jae [Hanyang University, Seoul (Korea, Republic of)

    2015-12-15

    Pipe wall-thinning by flow-accelerated corrosion (FAC) is a significant and costly damage of secondary system piping in nuclear power plants (NPPs). All NPPs have their management programs to ensure pipe integrity from wall-thinning. This study analyzed the pipe wall-thinning caused by changing the amine, which is used for adjusting the water chemistry in the secondary system of NPPs. The pH change was analyzed according to the addition of amine. Then, the wear rate calculated in two different amines was compared at the steam cycle in NPPs. As a result, increasing the pH at operating temperature (Hot pH) can reduce the rate of FAC damage significantly. Wall-thinning is affected by amine characteristics depending on temperature and quality of water.

  19. Expression of S-adenosylmethionine Hydrolase in Tissues Synthesizing Secondary Cell Walls Alters Specific Methylated Cell Wall Fractions and Improves Biomass Digestibility

    Directory of Open Access Journals (Sweden)

    Aymerick Eudes

    2016-07-01

    Full Text Available Plant biomass is a large source of fermentable sugars for the synthesis of bioproducts using engineered microbes. These sugars are stored as cell wall polymers, mainly cellulose and hemicellulose, and are embedded with lignin, which makes their enzymatic hydrolysis challenging. One of the strategies to reduce cell wall recalcitrance is the modification of lignin content and composition. Lignin is a phenolic polymer of methylated aromatic alcohols and its synthesis in tissues developing secondary cell walls is a significant sink for the consumption of the methyl donor S-adenosylmethionine (AdoMet. In this study, we demonstrate in Arabidopsis stems that targeted expression of S-adenosylmethionine hydrolase (AdoMetase, E.C. 3.3.1.2 in secondary cell-wall synthesizing tissues reduces the AdoMet pool and impacts lignin content and composition. In particular, both NMR analysis and pyrolysis gas chromatography mass spectrometry of lignin in engineered biomass showed relative enrichment of non-methylated p-hydroxycinnamyl (H units and a reduction of dimethylated syringyl (S units. This indicates a lower degree of methylation compared to that in wild-type lignin. Quantification of cell wall-bound hydroxycinnamates revealed a reduction of ferulate in AdoMetase transgenic lines. Biomass from transgenic lines, in contrast to that in control plants, exhibits an enrichment of glucose content and a reduction in the degree of hemicellulose glucuronoxylan methylation. We also show that these modifications resulted in a reduction of cell wall recalcitrance, because sugar yield generated by enzymatic biomass saccharification was greater than that of wild type plants. Considering that transgenic plants show no important diminution of biomass yields, and that heterologous expression of AdoMetase protein can be spatiotemporally optimized, this novel approach provides a valuable option for the improvement of lignocellulosic biomass feedstock.

  20. Secondary cell wall development in cotton fibers as examined with attenuated total reflection Fourier transform infrared spectroscopy

    Science.gov (United States)

    Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-IR) spectroscopy. The selected harvesting points coincide with secondary cell wall (SCW) development in the fibers. Progressive but moderat...

  1. Web-Enhanced, Standards-Oriented Teaching Units on Post-Wall Germany for the Secondary School Classroom.

    Science.gov (United States)

    Van Handle, Donna C.; Ayres, Evelyn; Cimino, Ellen; Dunn, Bryan; Foell, Kimberly; McCarthy, Jennifer K.

    2001-01-01

    Describes the creation and use of Web sites developed by secondary school teachers of German and European history who participated in an NEH-sponsored summer institute titled "Post-Wall Germany: Integrating Post-Unification German Culture into the High School Curriculum. Teacher participants also offer suggestions for using sites they created…

  2. Characterization of xylan in the early stages of secondary cell wall formation in tobacco bright yellow-2 cells.

    Science.gov (United States)

    Ishii, Tadashi; Matsuoka, Keita; Ono, Hiroshi; Ohnishi-Kameyama, Mayumi; Yaoi, Katsuro; Nakano, Yoshimi; Ohtani, Misato; Demura, Taku; Iwai, Hiroaki; Satoh, Shinobu

    2017-11-15

    The major polysaccharides present in the primary and secondary walls surrounding plant cells have been well characterized. However, our knowledge of the early stages of secondary wall formation is limited. To address this, cell walls were isolated from differentiating xylem vessel elements of tobacco bright yellow-2 (BY-2) cells induced by VASCULAR-RELATED NAC-DOMAIN7 (VND7). The walls of induced VND7-VP16-GR BY-2 cells consisted of cellulose, pectic polysaccharides, hemicelluloses, and lignin, and contained more xylan and cellulose compared with non-transformed BY-2 and uninduced VND7-VP16-GR BY-2 cells. A reducing end sequence of xylan containing rhamnose and galaturonic acid- residues is present in the walls of induced, uninduced, and non-transformed BY-2 cells. Glucuronic acid residues in xylan from walls of induced cells are O-methylated, while those of xylan in non-transformed BY-2 and uninduced cells are not. Our results show that xylan changes in chemical structure and amounts during the early stages of xylem differentiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A Novel Plasma Membrane-Anchored Protein Regulates Xylem Cell-Wall Deposition through Microtubule-Dependent Lateral Inhibition of Rho GTPase Domains.

    Science.gov (United States)

    Sugiyama, Yuki; Wakazaki, Mayumi; Toyooka, Kiminori; Fukuda, Hiroo; Oda, Yoshihisa

    2017-08-21

    Spatial control of cell-wall deposition is essential for determining plant cell shape [1]. Rho-type GTPases, together with the cortical cytoskeleton, play central roles in regulating cell-wall patterning [2]. In metaxylem vessel cells, which are the major components of xylem tissues, active ROP11 Rho GTPases form oval plasma membrane domains that locally disrupt cortical microtubules, thereby directing the formation of oval pits in secondary cell walls [3-5]. However, the regulatory mechanism that determines the planar shape of active Rho of Plants (ROP) domains is still unknown. Here we show that IQD13 associates with cortical microtubules and the plasma membrane to laterally restrict the localization of ROP GTPase domains, thereby directing the formation of oval secondary cell-wall pits. Loss and overexpression of IQD13 led to the formation of abnormally round and narrow secondary cell-wall pits, respectively. Ectopically expressed IQD13 increased the presence of parallel cortical microtubules by promoting microtubule rescue. A reconstructive approach revealed that IQD13 confines the area of active ROP domains within the lattice of the cortical microtubules, causing narrow ROP domains to form. This activity required the interaction of IQD13 with the plasma membrane. These findings suggest that IQD13 positively regulates microtubule dynamics as well as their linkage to the plasma membrane, which synergistically confines the area of active ROP domains, leading to the formation of oval secondary cell-wall pits. This finding sheds light on the role of microtubule-plasma membrane linkage as a lateral fence that determines the planar shape of Rho GTPase domains. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Intron-Mediated Alternative Splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B Regulates Cell Wall Thickening during Fiber Development in Populus Species1[W

    Science.gov (United States)

    Zhao, Yunjun; Sun, Jiayan; Xu, Peng; Zhang, Rui; Li, Laigeng

    2014-01-01

    Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation. PMID:24394777

  5. Intron-mediated alternative splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B regulates cell wall thickening during fiber development in Populus species.

    Science.gov (United States)

    Zhao, Yunjun; Sun, Jiayan; Xu, Peng; Zhang, Rui; Li, Laigeng

    2014-02-01

    Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation.

  6. Regulation of plant cells, cell walls and development by mechanical signals

    Energy Technology Data Exchange (ETDEWEB)

    Meyerowitz, Elliot M. [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2016-06-14

    The overall goal of the revised scope of work for the final year of funding was to characterize cell wall biosynthesis in developing cotyledons and in the shoot apical meristem of Arabidopsis thaliana, as a way of learning about developmental control of cell wall biosynthesis in plants, and interactions between cell wall biosynthesis and the microtubule cytoskeleton. The proposed work had two parts – to look at the effect of mutation in the SPIRAL2 gene on microtubule organization and reorganization, and to thoroughly characterize the glycosyltransferase genes expressed in shoot apical meristems by RNA-seq experiments, by in situ hybridization of the RNAs expressed in the meristem, and by antibody staining of the products of the glycosyltransferases in meristems. Both parts were completed; the spiral2 mutant was found to speed microtubule reorientation after ablation of adjacent cells, supporting our hypothesis that reorganization correlates with microtubule severing, the rate of which is increased by the mutation. The glycosyltransferase characterization was completed and published as Yang et al. (2016). Among the new things learned was that primary cell wall biosynthesis is strongly controlled both by cell type, and by stage of cell cycle, implying not only that different, even adjacent, cells can have different sugar linkages in their (nonshared) walls, but also that a surprisingly large proportion of glycosyltransferases is regulated in the cell cycle, and therefore that the cell cycle regulates wall maturation to a degree previously unrecognized.

  7. Effect of late planting and shading on cellulose synthesis during cotton fiber secondary wall development.

    Directory of Open Access Journals (Sweden)

    Ji Chen

    Full Text Available Cotton-rapeseed or cotton-wheat double cropping systems are popular in the Yangtze River Valley and Yellow River Valley of China. Due to the competition of temperature and light resources during the growing season of double cropping system, cotton is generally late-germinating and late-maturing and has to suffer from the coupling of declining temperature and low light especially in the late growth stage. In this study, late planting (LP and shading were used to fit the coupling stress, and the coupling effect on fiber cellulose synthesis was investigated. Two cotton (Gossypium hirsutum L. cultivars were grown in the field in 2010 and 2011 at three planting dates (25 April, 25 May and 10 June each with three shading levels (normal light, declined 20% and 40% PAR. Mean daily minimum temperature was the primary environmental factor affected by LP. The coupling of LP and shading (decreased cellulose content by 7.8%-25.5% produced more severe impacts on cellulose synthesis than either stress alone, and the effect of LP (decreased cellulose content by 6.7%-20.9% was greater than shading (decreased cellulose content by 0.7%-5.6%. The coupling of LP and shading hindered the flux from sucrose to cellulose by affecting the activities of related cellulose synthesis enzymes. Fiber cellulose synthase genes expression were delayed under not only LP but shading, and the coupling of LP and shading markedly postponed and even restrained its expression. The decline of sucrose-phosphate synthase activity and its peak delay may cause cellulose synthesis being more sensitive to the coupling stress during the later stage of fiber secondary wall development (38-45 days post-anthesis. The sensitive difference of cellulose synthesis between two cultivars in response to the coupling of LP and shading may be mainly determined by the sensitiveness of invertase, sucrose-phosphate synthase and cellulose synthase.

  8. The secondary stress analyses in the fuel pin cladding due to the swelling gradient across the wall thickness

    International Nuclear Information System (INIS)

    Uwaba, Tomoyuki; Ukai, Shigeharu

    2002-01-01

    Irradiation deformation analyses of FBR fuel cladding were made by using the finite element method. In these analyses the history of the stress occurred in the cladding was evaluated paying attention to the secondary stress induced by the swelling difference across the wall thickness. It was revealed that the difference of the swelling incubation dose in the direction of the thickness and the irradiation creep deformation play an important role in the history of the secondary stress. The effect of the stress-enhanced swelling was also analyzed in this study

  9. The CWI Pathway: Regulation of the Transcriptional Adaptive Response to Cell Wall Stress in Yeast

    Directory of Open Access Journals (Sweden)

    Ana Belén Sanz

    2017-12-01

    Full Text Available Fungi are surrounded by an essential structure, the cell wall, which not only confers cell shape but also protects cells from environmental stress. As a consequence, yeast cells growing under cell wall damage conditions elicit rescue mechanisms to provide maintenance of cellular integrity and fungal survival. Through transcriptional reprogramming, yeast modulate the expression of genes important for cell wall biogenesis and remodeling, metabolism and energy generation, morphogenesis, signal transduction and stress. The yeast cell wall integrity (CWI pathway, which is very well conserved in other fungi, is the key pathway for the regulation of this adaptive response. In this review, we summarize the current knowledge of the yeast transcriptional program elicited to counterbalance cell wall stress situations, the role of the CWI pathway in the regulation of this program and the importance of the transcriptional input received by other pathways. Modulation of this adaptive response through the CWI pathway by positive and negative transcriptional feedbacks is also discussed. Since all these regulatory mechanisms are well conserved in pathogenic fungi, improving our knowledge about them will have an impact in the developing of new antifungal therapies.

  10. Toward Optic Flow Regulation for Wall-Following and Centring Behaviours

    Directory of Open Access Journals (Sweden)

    Julien Serres

    2006-06-01

    Full Text Available In our ongoing project on the autonomous guidance of Micro-Air Vehicles (MAVs in confined indoor and outdoor environments, we have developed a bio-inspired optic flow based autopilot enabling a hovercraft to travel safely, and avoid the walls of a corridor. The hovercraft is an air vehicle endowed with natural roll and pitch stabilization characteristics, in which planar flight control can be developed conveniently. It travels at a constant ground height (∼2mm and senses the environment by means of two lateral eyes that measure the right and left optic flows (OFs. The visuomotor feedback loop, which is called LORA(1 (Lateral Optic flow Regulation Autopilot, Mark 1, consists of a lateral OF regulator that adjusts the hovercraft's yaw velocity and keeps the lateral OF constant on one wall equal to an OF set-point. Simulations have shown that the hovercraft manages to navigate in a corridor at a “preset” groundspeed (1m/s without requiring a supervisor to make it switch abruptly between the control-laws corresponding to behaviours such as automatic wall-following, automatic centring, and automatically reacting to an opening encountered on a wall. The passive visual sensors and the simple control system used here are suitable for use on MAVs with an avionic payload of only a few grams.

  11. Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB.

    Science.gov (United States)

    Schirner, Kathrin; Eun, Ye-Jin; Dion, Mike; Luo, Yun; Helmann, John D; Garner, Ethan C; Walker, Suzanne

    2015-01-01

    The bacterial actin homolog MreB, which is crucial for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of lipid-linked peptidoglycan precursors. When precursors are depleted, MreB filaments disassemble into the cytoplasm, and peptidoglycan synthesis becomes disorganized. In cells that lack wall teichoic acids but continue to make peptidoglycan, dynamic MreB filaments are observed, although their presence is not sufficient to establish a rod shape. We propose that the cell regulates MreB filament association with the membrane, allowing rapid and reversible inactivation of cell wall enzyme complexes in response to the inhibition of cell wall synthesis.

  12. Toward optic flow regulation for wall-following and centring behaviours

    Directory of Open Access Journals (Sweden)

    Franck Ruffier

    2008-11-01

    Full Text Available In our ongoing project on the autonomous guidance of Micro-Air Vehicles (MAVs in confined indoor and outdoor environments, we have developed a bio-inspired optic flow based autopilot enabling a hovercraft to travel safely, and avoid the walls of a corridor. The hovercraft is an air vehicle endowed with natural roll and pitch stabilization characteristics, in which planar flight control can be developed conveniently. It travels at a constant ground height (~2mm and senses the environment by means of two lateral eyes that measure the right and left optic flows (OFs. The visuomotor feedback loop, which is called LORA(1 (Lateral Optic flow Regulation Autopilot, Mark 1, consists of a lateral OF regulator that adjusts the hovercraft's yaw velocity and keeps the lateral OF constant on one wall equal to an OF set-point. Simulations have shown that the hovercraft manages to navigate in a corridor at a "pre-set" groundspeed (1m/s without requiring a supervisor to make it switch abruptly between the control-laws corresponding to behaviours such as automatic wall-following, automatic centring, and automatically reacting to an opening encountered on a wall. The passive visual sensors and the simple control system used here are suitable for use on MAVs with an avionic payload of only a few grams.

  13. Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB

    OpenAIRE

    Schirner, Kathrin; Eun, Ye-Jin; Dion, Mike; Luo, Yun; Helmann, John D.; Garner, Ethan C.; Walker, Suzanne

    2014-01-01

    Summary The bacterial actin homolog MreB, which is critical for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of li...

  14. The Effects of Interactive Word Walls on Students with Learning Disabilities in the Secondary Science Classroom

    Science.gov (United States)

    Eustace-DeBaun, Casey Elizabeth

    Effective approaches for teaching vocabulary to various populations of learners is a topic of current research (Barr, Eslami, & Malatesha, 2012) yet little research is dedicated to students with learning disabilities in the science classroom. Within this study the interac-tive word wall was used as a tool to build vocabulary and to encourage usage of new sub-ject-specific terminology. The experiment utilized quasi-experimental pre-post test com-parison group design using interrupted time-series (Johnson & Christiensen, 2007) due to the inability to randomize participants and establish a clear control group. The data was collected across four units of terminology and with a student satisfaction survey. Stu-dents reported at least seventy percent satisfaction with the use of Interactive Word Walls and demonstrated some performance increase in both vocabulary retention and reading comprehension when utilizing Interactive Word Walls.

  15. Studying Secondary Growth and Bast Fiber Development: The Hemp Hypocotyl Peeks behind the Wall

    Czech Academy of Sciences Publication Activity Database

    Behr, M.; Legay, S.; Žižková, Eva; Motyka, Václav; Dobrev, Petre; Hausman, J.F.; Lutts, S.; Guerriero, G.

    2016-01-01

    Roč. 7, NOV 18 (2016), č. článku 1733. ISSN 1664-462X R&D Projects: GA ČR(CZ) GA16-14649S Institutional support: RVO:61389030 Keywords : plant-cell-wall * arabidopsis-thaliana * cannabis-sativa * lignin biosynthesis * microarray analysis * gene-expression * in-silico * anthocyanin biosynthesis * arabinogalactan-protein * transcription factors * Cannabis sativa * hypocotyl * bast fibers * cell wall * RNA-Seq * immunohistochemistry * phytohormones Subject RIV: EF - Botanics Impact factor: 4.298, year: 2016

  16. The carbohydrate-binding module (CBM)-like sequence is crucial for rice CWA1/BC1 function in proper assembly of secondary cell wall materials.

    Science.gov (United States)

    Sato, Kanna; Ito, Sachiko; Fujii, Takeo; Suzuki, Ryu; Takenouchi, Sachi; Nakaba, Satoshi; Funada, Ryo; Sano, Yuzou; Kajita, Shinya; Kitano, Hidemi; Katayama, Yoshihiro

    2010-11-01

    We recently reported that the cwa1 mutation disturbed the deposition and assembly of secondary cell wall materials in the cortical fiber of rice internodes. Genetic analysis revealed that cwa1 is allelic to bc1, which encodes glycosylphosphatidylinositol (GPI)-anchored COBRA-like protein with the highest homology to Arabidopsis COBRA-like 4 (COBL4) and maize Brittle Stalk 2 (Bk2). Our results suggested that CWA1/BC1 plays a role in assembling secondary cell wall materials at appropriate sites, enabling synthesis of highly ordered secondary cell wall structure with solid and flexible internodes in rice. The N-terminal amino acid sequence of CWA1/BC1, as well as its orthologs (COBL4, Bk2) and other BC1-like proteins in rice, shows weak similarity to a family II carbohydrate-binding module (CBM2) of several bacterial cellulases. To investigate the importance of the CBM-like sequence of CWA1/BC1 in the assembly of secondary cell wall materials, Trp residues in the CBM-like sequence, which is important for carbohydrate binding, were substituted for Val residues and introduced into the cwa1 mutant. CWA1/BC1 with the mutated sequence did not complement the abnormal secondary cell walls seen in the cwa1 mutant, indicating that the CBM-like sequence is essential for the proper function of CWA1/BC1, including assembly of secondary cell wall materials.

  17. A temperature-sensitive allele of a putative mRNA splicing helicase down-regulates many cell wall genes and causes radial swelling in Arabidopsis thaliana.

    Science.gov (United States)

    Howles, Paul A; Gebbie, Leigh K; Collings, David A; Varsani, Arvind; Broad, Ronan C; Ohms, Stephen; Birch, Rosemary J; Cork, Ann H; Arioli, Tony; Williamson, Richard E

    2016-05-01

    The putative RNA helicase encoded by the Arabidopsis gene At1g32490 is a homolog of the yeast splicing RNA helicases Prp2 and Prp22. We isolated a temperature-sensitive allele (rsw12) of the gene in a screen for root radial swelling mutants. Plants containing this allele grown at the restrictive temperature showed weak radial swelling, were stunted with reduced root elongation, and contained reduced levels of cellulose. The role of the protein was further explored by microarray analysis. By using both fold change cutoffs and a weighted gene coexpression network analysis (WGCNA) to investigate coexpression of genes, we found that the radial swelling phenotype was not linked to genes usually associated with primary cell wall biosynthesis. Instead, the mutation has strong effects on expression of secondary cell wall related genes. Many genes potentially associated with secondary walls were present in the most significant WGCNA module, as were genes coding for arabinogalactans and proteins with GPI anchors. The proportion of up-regulated genes that possess introns in rsw12 was above that expected if splicing was unrelated to the activity of the RNA helicase, suggesting that the helicase does indeed play a role in splicing in Arabidopsis. The phenotype may be due to a change in the expression of one or more genes coding for cell wall proteins.

  18. Affective Self-Regulation Trajectories during Secondary School Predict Substance Use among Urban Minority Young Adults

    Science.gov (United States)

    Griffin, Kenneth W.; Lowe, Sarah R.; Acevedo, Bianca P.; Botvin, Gilbert J.

    2015-01-01

    This study explored the relationship between trajectories of affective self-regulation skills during secondary school and young adult substance use in a large multiethnic, urban sample (N = 995). During secondary school, participants completed a measure of cognitive and behavioral skills used to control negative, unpleasant emotions or perceived…

  19. Regulation of cellular communication by signaling microdomains in the blood vessel wall.

    Science.gov (United States)

    Billaud, Marie; Lohman, Alexander W; Johnstone, Scott R; Biwer, Lauren A; Mutchler, Stephanie; Isakson, Brant E

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function.

  20. Regulation of Cellular Communication by Signaling Microdomains in the Blood Vessel Wall

    Science.gov (United States)

    Billaud, Marie; Lohman, Alexander W.; Johnstone, Scott R.; Biwer, Lauren A.; Mutchler, Stephanie; Isakson, Brant E.

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function. PMID:24671377

  1. New cooling regulation technology of secondary cooling station in DCS

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Yan, Jun-wei; Zhu, Dong-sheng; Liu, Fei-long; Lei, Jun-xi [The Key Lab of Enhanced Heat Transfer and Energy Conservation of Ministry of Education, School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510641 (China); Liang, Lie-quan [The Key Lab of E-Commerce Market Application Technology of Guangdong Province, Guangdong University of Business Studies, Guangzhou 510320 (China)

    2008-07-01

    In this paper, a kind of new control technology of secondary cooling station (constant flow rate/variable temperature difference) in district cooling system (DCS) is proposed in view of serial consequences including low efficiency and high operating cost caused by low temperature of supply water in DCS. This technology has been applied in DCS of Guangzhou University City. The result has already indicated that such technology can increase the supply and return temperatures of buildings, return water temperature of primary side in the plate heat exchanger unit, moreover, the efficiency of both the chiller and the whole system are improved significantly. (author)

  2. Identification of lignin genes and regulatory sequences involved in secondary cell wall formation in Acacia auriculiformis and Acacia mangium via de novo transcriptome sequencing

    Directory of Open Access Journals (Sweden)

    Cannon Charles H

    2011-07-01

    Full Text Available Abstract Background Acacia auriculiformis × Acacia mangium hybrids are commercially important trees for the timber and pulp industry in Southeast Asia. Increasing pulp yield while reducing pulping costs are major objectives of tree breeding programs. The general monolignol biosynthesis and secondary cell wall formation pathways are well-characterized but genes in these pathways are poorly characterized in Acacia hybrids. RNA-seq on short-read platforms is a rapid approach for obtaining comprehensive transcriptomic data and to discover informative sequence variants. Results We sequenced transcriptomes of A. auriculiformis and A. mangium from non-normalized cDNA libraries synthesized from pooled young stem and inner bark tissues using paired-end libraries and a single lane of an Illumina GAII machine. De novo assembly produced a total of 42,217 and 35,759 contigs with an average length of 496 bp and 498 bp for A. auriculiformis and A. mangium respectively. The assemblies of A. auriculiformis and A. mangium had a total length of 21,022,649 bp and 17,838,260 bp, respectively, with the largest contig 15,262 bp long. We detected all ten monolignol biosynthetic genes using Blastx and further analysis revealed 18 lignin isoforms for each species. We also identified five contigs homologous to R2R3-MYB proteins in other plant species that are involved in transcriptional regulation of secondary cell wall formation and lignin deposition. We searched the contigs against public microRNA database and predicted the stem-loop structures of six highly conserved microRNA families (miR319, miR396, miR160, miR172, miR162 and miR168 and one legume-specific family (miR2086. Three microRNA target genes were predicted to be involved in wood formation and flavonoid biosynthesis. By using the assemblies as a reference, we discovered 16,648 and 9,335 high quality putative Single Nucleotide Polymorphisms (SNPs in the transcriptomes of A. auriculiformis and A. mangium

  3. Brittle stalk 2 encodes a putative glycosylphosphatidylinositol-anchored protein that affects mechanical strength of maize tissues by altering the composition and structure of secondary cell walls.

    Science.gov (United States)

    Ching, Ada; Dhugga, Kanwarpal S; Appenzeller, Laura; Meeley, Robert; Bourett, Timothy M; Howard, Richard J; Rafalski, Antoni

    2006-10-01

    A spontaneous maize mutant, brittle stalk-2 (bk2-ref), exhibits dramatically reduced tissue mechanical strength. Reduction in mechanical strength in the stalk tissue was highly correlated with a reduction in the amount of cellulose and an uneven deposition of secondary cell wall material in the subepidermal and perivascular sclerenchyma fibers. Cell wall accounted for two-thirds of the observed reduction in dry matter content per unit length of the mutant stalk in comparison to the wildtype stalk. Although the cell wall composition was significantly altered in the mutant in comparison to the wildtype stalks, no compensation by lignin and cell wall matrix for reduced cellulose amount was observed. We demonstrate that Bk2 encodes a Cobra-like protein that is homologous to the rice Bc1 protein. In the bk2-ref gene, a 1 kb transposon-like element is inserted in the beginning of the second exon, disrupting the open reading frame. The Bk2 gene was expressed in the stalk, husk, root, and leaf tissues, but not in the embryo, endosperm, pollen, silk, or other tissues with comparatively few or no secondary cell wall containing cells. The highest expression was in the isolated vascular bundles. In agreement with its role in secondary wall formation, the expression pattern of the Bk2 gene was very similar to that of the ZmCesA10, ZmCesA11, and ZmCesA12 genes, which are known to be involved in secondary wall formation. We have isolated an independent Mutator-tagged allele of bk2, referred to as bk2-Mu7, the phenotype of which is similar to that of the spontaneous mutant. Our results demonstrate that mutations in the Bk2 gene affect stalk strength in maize by interfering with the deposition of cellulose in the secondary cell wall in fiber cells.

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

    Directory of Open Access Journals (Sweden)

    Toshiaki eTameshige

    2015-05-01

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

  5. A Novel Family of Cell Wall-Related Proteins Regulated Differently during the Yeast Life Cycle

    Science.gov (United States)

    Rodríguez-Peña, José Manuel; Cid, Víctor J.; Arroyo, Javier; Nombela, César

    2000-01-01

    The Saccharomyces cerevisiae Ygr189c, Yel040w, and Ylr213c gene products show significant homologies among themselves and with various bacterial β-glucanases and eukaryotic endotransglycosidases. Deletion of the corresponding genes, either individually or in combination, did not produce a lethal phenotype. However, the removal of YGR189c and YEL040w, but not YLR213c, caused additive sensitivity to compounds that interfere with cell wall construction, such as Congo red and Calcofluor White, and overexpression of YEL040w led to resistance to these compounds. These genes were renamed CRH1 and CRH2, respectively, for Congo red hypersensitive. By site-directed mutagenesis we found that the putative glycosidase domain of CRH1 was critical for its function in complementing hypersensitivity to the inhibitors. The involvement of CRH1 and CRH2 in the development of cell wall architecture was clearly shown, since the alkali-soluble glucan fraction in the crh1Δ crh2Δ strain was almost twice the level in the wild-type. Interestingly, the three genes were subject to different patterns of transcriptional regulation. CRH1 and YLR213c (renamed CRR1, for CRH related) were found to be cell cycle regulated and also expressed under sporulation conditions, whereas CRH2 expression did not vary during the mitotic cycle. Crh1 and Crh2 are localized at the cell surface, particularly in chitin-rich areas. Consistent with the observed expression patterns, Crh1–green fluorescent protein was found at the incipient bud site, around the septum area in later stages of budding, and in ascospore envelopes. Crh2 was found to localize mainly at the bud neck throughout the whole budding cycle, in mating projections and zygotes, but not in ascospores. These data suggest that the members of this family of putative glycosidases might exert a common role in cell wall organization at different stages of the yeast life cycle. PMID:10757808

  6. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 2: Assessing the influence of vapor wall losses

    OpenAIRE

    Cappa, Christopher D.; Jathar, Shantanu H.; Kleeman, Michael J.; Docherty, Kenneth S.; Jimenez, Jose L.; Seinfeld, John H.; Wexler, Anthony S.

    2016-01-01

    The influence of losses of organic vapors to chamber walls during secondary organic aerosol (SOA) formation experiments has recently been established. Here, the influence of such losses on simulated ambient SOA concentrations and properties is assessed in the UCD/CIT regional air quality model using the statistical oxidation model (SOM) for SOA. The SOM was fit to laboratory chamber data both with and without accounting for vapor wall losses following the approa...

  7. THE DEVELOPMENT OF THE SECONDARY WALL OF THE XYLEM IN ACER PSEUDOPLATANUS

    Science.gov (United States)

    Wooding, F. B. P.; Northcote, D. H.

    1964-01-01

    The development of the spirally thickened xylem element from a cambium initial of sycamore Acer pseudoplatanus has been traced by means of electron microscopy. The narrow elongated cambial initial undergoes considerable expansion in all dimensions. The cytoplasm at this stage is distributed in a thin skin between the cell wall and a large vacuole. No correlation has been observed between the distribution of any organelle and the pattern of the eventual thickenings. After the sites of thickening deposition have become apparent, the most conspicuous feature of the cell is the proliferation of Golgi bodies and vesicles. It is suggested that the material of the developing thickenings stems from direct apposition of the material in the Golgi vesicles. After glutaraldehyde fixation, microtubules (200 to 220 A in diameter) are seen to be sited in specific relation to the thickenings, the orientation of the tubules mirroring that of the fibrils seen in the thickenings. Possible reasons for absence of an observable pattern in the expanded but relatively undifferentiated cell are given, and the possible roles of the Golgi apparatus and microtubules in the thickening production are discussed PMID:14222817

  8. Asparagus Spears as a Model to Study Heteroxylan Biosynthesis during Secondary Wall Development.

    Directory of Open Access Journals (Sweden)

    Lili Song

    Full Text Available Garden asparagus (Asparagus officinalis L. is a commercially important crop species utilized for its excellent source of vitamins, minerals and dietary fiber. However, after harvest the tissue hardens and its quality rapidly deteriorates because spear cell walls become rigidified due to lignification and substantial increases in heteroxylan content. This latter observation prompted us to investigate the in vitro xylan xylosyltransferase (XylT activity in asparagus. The current model system for studying heteroxylan biosynthesis, Arabidopsis, whilst a powerful genetic system, displays relatively low xylan XylT activity in in vitro microsomal preparations compared with garden asparagus therefore hampering our ability to study the molecular mechanism(s of heteroxylan assembly. Here, we analyzed physiological and biochemical changes of garden asparagus spears stored at 4 °C after harvest and detected a high level of xylan XylT activity that accounts for this increased heteroxylan. The xylan XylT catalytic activity is at least thirteen-fold higher than that reported for previously published species, including Arabidopsis and grasses. A biochemical assay was optimized and up to seven successive Xyl residues were incorporated to extend the xylotetraose (Xyl4 acceptor backbone. To further elucidate the xylan biosynthesis mechanism, we used RNA-seq to generate an Asparagus reference transcriptome and identified five putative xylan biosynthetic genes (AoIRX9, AoIRX9-L, AoIRX10, AoIRX14_A, AoIRX14_B with AoIRX9 having an expression profile that is distinct from the other genes. We propose that Asparagus provides an ideal biochemical system to investigate the biochemical aspects of heteroxylan biosynthesis and also offers the additional benefit of being able to study the lignification process during plant stem maturation.

  9. Asparagus Spears as a Model to Study Heteroxylan Biosynthesis during Secondary Wall Development.

    Science.gov (United States)

    Song, Lili; Zeng, Wei; Wu, Aimin; Picard, Kelsey; Lampugnani, Edwin R; Cheetamun, Roshan; Beahan, Cherie; Cassin, Andrew; Lonsdale, Andrew; Doblin, Monika S; Bacic, Antony

    2015-01-01

    Garden asparagus (Asparagus officinalis L.) is a commercially important crop species utilized for its excellent source of vitamins, minerals and dietary fiber. However, after harvest the tissue hardens and its quality rapidly deteriorates because spear cell walls become rigidified due to lignification and substantial increases in heteroxylan content. This latter observation prompted us to investigate the in vitro xylan xylosyltransferase (XylT) activity in asparagus. The current model system for studying heteroxylan biosynthesis, Arabidopsis, whilst a powerful genetic system, displays relatively low xylan XylT activity in in vitro microsomal preparations compared with garden asparagus therefore hampering our ability to study the molecular mechanism(s) of heteroxylan assembly. Here, we analyzed physiological and biochemical changes of garden asparagus spears stored at 4 °C after harvest and detected a high level of xylan XylT activity that accounts for this increased heteroxylan. The xylan XylT catalytic activity is at least thirteen-fold higher than that reported for previously published species, including Arabidopsis and grasses. A biochemical assay was optimized and up to seven successive Xyl residues were incorporated to extend the xylotetraose (Xyl4) acceptor backbone. To further elucidate the xylan biosynthesis mechanism, we used RNA-seq to generate an Asparagus reference transcriptome and identified five putative xylan biosynthetic genes (AoIRX9, AoIRX9-L, AoIRX10, AoIRX14_A, AoIRX14_B) with AoIRX9 having an expression profile that is distinct from the other genes. We propose that Asparagus provides an ideal biochemical system to investigate the biochemical aspects of heteroxylan biosynthesis and also offers the additional benefit of being able to study the lignification process during plant stem maturation.

  10. The temperature control and water quality regulation for steam generator secondary side hydrostatic test

    International Nuclear Information System (INIS)

    Xiao Bo; Liu Dongyong

    2014-01-01

    The secondary side hydrostatic test for the steam generator of M310 unit is to verify the pressure tightness of steam generator secondary side tube sheet and related systems. As for the importance of the steam generator, the water temperature and water quality of hydrostatic test has strict requirements. The discussion on the water temperature control and water quality regulation for the secondary loop hydrostatic test of Fuqing Unit 1 contribute greatly to the guiding work for the preparation of the steam generator pressure test for M310 unit. (authors)

  11. A R2R3-MYB transcription factor that is specifically expressed in cotton (Gossypium hirsutum) fibers affects secondary cell wall biosynthesis and deposition in transgenic Arabidopsis.

    Science.gov (United States)

    Sun, Xiang; Gong, Si-Ying; Nie, Xiao-Ying; Li, Yang; Li, Wen; Huang, Geng-Qing; Li, Xue-Bao

    2015-07-01

    Secondary cell wall (SCW) is an important industrial raw material for pulping, papermaking, construction, lumbering, textiles and potentially for biofuel production. The process of SCW thickening of cotton fibers lays down the cellulose that will constitute the bulk (up to 96%) of the fiber at maturity. In this study, a gene encoding a MYB-domain protein was identified in cotton (Gossypium hirsutum) and designated as GhMYBL1. Quantitative real-time polymerase chain reaction (RT-PCR) analysis revealed that GhMYBL1 was specifically expressed in cotton fibers at the stage of secondary wall deposition. Further analysis indicated that this protein is a R2R3-MYB transcription factor, and is targeted to the cell nucleus. Overexpression of GhMYBL1 in Arabidopsis affected the formation of SCW in the stem xylem of the transgenic plants. The enhanced SCW thickening also occurred in the interfascicular fibers, xylary fibers and vessels of the GhMYBL1-overexpression transgenic plants. The expression of secondary wall-associated genes, such as CesA4, CesA7, CesA8, PAL1, F5H and 4CL1, were upregulated, and consequently, cellulose and lignin biosynthesis were enhanced in the GhMYBL1 transgenic plants. These data suggested that GhMYBL1 may participate in modulating the process of secondary wall biosynthesis and deposition of cotton fibers. © 2014 Scandinavian Plant Physiology Society.

  12. Stiff mutant genes of Phycomyces target turgor pressure and wall mechanical properties to regulate elongation growth rate

    Directory of Open Access Journals (Sweden)

    Joseph K. E. Ortega

    2012-05-01

    Full Text Available Regulation of cell growth is paramount to all living organisms. In plants, algae and fungi, regulation of expansive growth of cells is required for development and morphogenesis. Also, many sensory responses of stage IVb sporangiophores of Phycomyces blakesleeanus are produced by regulating elongation growth rate (growth responses and differential elongation growth rate (tropic responses. Stiff mutant sporangiophores exhibit diminished tropic responses and are found to be defective in at least four genes; madD, madE, madF and madG. Prior experimental research suggests that the defective genes affect growth regulation, but this was not verified. All the growth of the single-celled stalk of the stage IVb sporangiophore occurs in a short region termed the growth zone. Prior experimental and theoretical research indicates that elongation growth rate of the stage IVb sporangiophore can be regulated by controlling the cell wall mechanical properties within the growth zone and the magnitude of the turgor pressure. A quantitative biophysical model for elongation growth rate is required to elucidate the relationship between wall mechanical properties and turgor pressure during growth regulation. In this study, it is hypothesized that the mechanical properties of the wall within the growth zone of stiff mutant sporangiophores are different compared to wild type. A biophysical equation for elongation growth rate is derived for fungal and plant cells with a growth zone. Two strains of stiff mutants are studied, C149 madD120 (- and C216 geo- (-. Experimental results demonstrate that turgor pressure is larger but irreversible deformation rates of the wall within the growth zone and growth zone length are smaller for stiff mutant sporangiophores compared to wild type. These findings explain the diminished tropic responses of the stiff mutant sporangiophores and suggest that the defective genes affect the amount of wall-building material delivered to the inner

  13. Illumina microRNA profiles reveal the involvement of miR397a in Citrus adaptation to long-term boron toxicity via modulating secondary cell-wall biosynthesis.

    Science.gov (United States)

    Huang, Jing-Hao; Qi, Yi-Ping; Wen, Shou-Xing; Guo, Peng; Chen, Xiao-Min; Chen, Li-Song

    2016-03-10

    The mechanisms underlying tolerance to B-toxicity in plants are still controversial. Our previous studies indicated that B-toxicity is mainly limited to leaves in Citrus and that alternations of cell-wall structure in vascular bundles are involved in tolerance to B-toxicity. Here, miRNAs and their expression patterns were first identified in B-treated Citrus sinensis (tolerant) and C. grandis (intolerant) leaves via high-throughput sequencing. Candidate miRNAs were then verified with molecular and anatomical approaches. The results showed that 51 miRNAs in C. grandis and 20 miRNAs in C. sinensis were differentially expressed after B-toxic treatment. MiR395a and miR397a were the most significantly up-regulated miRNAs in B-toxic C. grandis leaves, but both were down-regulated in B-toxic C. sinensis leaves. Four auxin response factor genes and two laccase (LAC) genes were confirmed through 5'-RACE to be real targets of miR160a and miR397a, respectively. Up-regulation of LAC4 resulted in secondary deposition of cell-wall polysaccharides in vessel elements of C. sinensis, whereas down-regulation of both LAC17 and LAC4, led to poorly developed vessel elements in C. grandis. Our findings demonstrated that miR397a plays a pivotal role in woody Citrus tolerance to B-toxicity by targeting LAC17 and LAC4, both of which are responsible for secondary cell-wall synthesis.

  14. New opportunities for the regulation of secondary metabolism in plants: focus on microRNAs.

    Science.gov (United States)

    Bulgakov, Victor P; Avramenko, Tatiana V

    2015-09-01

    Plant cell cultures are of particular interest in industrial applications as a source of biologically active substances. It is difficult, however, to achieve stable production of secondary metabolites for many plant cell cultures using classical techniques. Novel approaches should be developed for removal of the inhibitor blocks that prevent pathway activation and shift the regulatory balance to the activation of entire biosynthetic pathways. MicroRNAs (miRNAs) are small RNAs that play important regulatory roles in various biological processes. Only recently miRNAs have been demonstrated as active in secondary metabolism regulation. In this work, we summarize recent data on the emerging approaches based on regulation of secondary metabolism by miRNAs.

  15. Dissecting the regulation of pollen tube growth by modelling the interplay of hydrodynamics, cell wall and ion dynamics

    Directory of Open Access Journals (Sweden)

    Junli eLiu

    2014-08-01

    Full Text Available Hydrodynamics, cell wall and ion dynamics are all important properties that regulate pollen tube growth. Currently, the two main pollen tube growth models, the cell wall model and the hydrodynamic model do not appear to be reconcilable. Here we develop an integrative model for pollen tube growth and show that our model reproduces key experimental observations: 1 that the hypertonic condition leads to a much longer oscillatory period and that the hypotonic condition halves the oscillatory period; 2 that oscillations in turgor are experimentally undetectable; 3 that increasing the extracellular calcium concentration or decreasing the pH decreases the growth oscillatory amplitude; 4 that knockout of Raba4d, a member of the Rab family of small GTPase proteins, decreases pollen tube length after germination for 24 hours. Using the model generated here, we reveal that 1 when cell wall extensibility is large, pollen tube may sustain growth at different volume changes and maintain relatively stable turgor; 2 turgor increases if cell wall extensibility decreases; 3 increasing turgor due to decrease in osmolarity in the media, although very small, increases volume change . However, increasing turgor due to decrease in cell wall extensibility decreases volume change. In this way regulation of pollen tube growth by turgor is context dependent. By changing the osmolarity in the media, the main regulatory points are extracellular osmolarity for water flow and turgor for the volume encompassed by the cell wall. However, if the viscosity of cell wall changes, the main regulatory points are turgor for water flow and wall extensibility for the volume encompassed by the cell wall. The novel methodology developed here reveals the underlying context-dependent regulatory principle of pollen tube growth.

  16. Breakdown of a Space Charge Limited Regime of a Sheath in a Weakly Collisional Plasma Bounded by Walls with Secondary Electron Emission

    International Nuclear Information System (INIS)

    Sydorenko, D.; Smolyakov, A.; Kaganovich, I.; Raitses, Y.

    2009-01-01

    A new regime of plasma-wall interaction is identified in particle-in-cell simulations of a hot plasma bounded by walls with secondary electron emission. Such a plasma has a strongly non-Maxwellian electron velocity distribution function and consists of bulk plasma electrons and beams of secondary electrons. In the new regime, the plasma sheath is not in a steady space charge limited state even though the secondary electron emission produced by the plasma bulk electrons is so intense that the corresponding partial emission coefficient exceeds unity. Instead, the plasma-sheath system performs relaxation oscillations by switching quasiperiodically between the space charge limited and non-space-charge limited states.

  17. Regulation of Cell Wall Plasticity by Nucleotide Metabolism in Lactococcus lactis*

    Science.gov (United States)

    Solopova, Ana; Formosa-Dague, Cécile; Courtin, Pascal; Furlan, Sylviane; Veiga, Patrick; Péchoux, Christine; Armalyte, Julija; Sadauskas, Mikas; Kok, Jan; Hols, Pascal; Dufrêne, Yves F.; Kuipers, Oscar P.; Chapot-Chartier, Marie-Pierre; Kulakauskas, Saulius

    2016-01-01

    To ensure optimal cell growth and separation and to adapt to environmental parameters, bacteria have to maintain a balance between cell wall (CW) rigidity and flexibility. This can be achieved by a concerted action of peptidoglycan (PG) hydrolases and PG-synthesizing/modifying enzymes. In a search for new regulatory mechanisms responsible for the maintenance of this equilibrium in Lactococcus lactis, we isolated mutants that are resistant to the PG hydrolase lysozyme. We found that 14% of the causative mutations were mapped in the guaA gene, the product of which is involved in purine metabolism. Genetic and transcriptional analyses combined with PG structure determination of the guaA mutant enabled us to reveal the pivotal role of the pyrB gene in the regulation of CW rigidity. Our results indicate that conversion of l-aspartate (l-Asp) to N-carbamoyl-l-aspartate by PyrB may reduce the amount of l-Asp available for PG synthesis and thus cause the appearance of Asp/Asn-less stem peptides in PG. Such stem peptides do not form PG cross-bridges, resulting in a decrease in PG cross-linking and, consequently, reduced PG thickness and rigidity. We hypothesize that the concurrent utilization of l-Asp for pyrimidine and PG synthesis may be part of the regulatory scheme, ensuring CW flexibility during exponential growth and rigidity in stationary phase. The fact that l-Asp availability is dependent on nucleotide metabolism, which is tightly regulated in accordance with the growth rate, provides L. lactis cells the means to ensure optimal CW plasticity without the need to control the expression of PG synthesis genes. PMID:27022026

  18. Regulation of Hypertension for Secondary Prevention of Stroke: The Possible 'Bridging Function' of Acupuncture.

    Science.gov (United States)

    Zheng, Haizhen; Han, Yuhui; Du, Yuzheng; Shi, Xuemin; Huang, Huiyuan; Yu, Xiaoyang; Tan, Xiaochan; Hu, Chunxiao; Wang, Yue; Zhou, Shiyuan

    2018-01-01

    Worldwide, stroke is the leading cause of mortality and disability, with hypertension being an independent risk factor for a secondary stroke. Acupuncture for the treatment of hypertension gains more attention in alternative and complementary medicine, but the results are inconsistent. Few studies regarding the secondary prevention of stroke by managing hypertension with acupuncture have been carried out as there are some problems regarding the antihypertensive drug status in the secondary prevention of stroke. Still, the potential of acupuncture in regulating the blood pressure for secondary stroke prevention deserves our focus. This review is based on papers recorded in the PubMed, Embase, and Web of Science databases, from their inception until March 28, 2017, and retrieved with the following search terms: hypertension and acupuncture, limited in spontaneously hypertensive rats (SHRs), stress-induced (or cold-induced) hypertensive or pre-hypertensive models. We find that, in these hypertensive animals, acupuncture could mainly influence factors related to the nervous system, oxidative stress, the endocrine system, cardiovascular function, and hemorheology, which are closely associated with the stroke outcome. This trend may give us a hint that acupuncture might well participate in the secondary prevention of stroke through these pathways when used in the management of hypertension. © 2018 S. Karger GmbH, Freiburg.

  19. Arabidopsis wat1 (walls are thin1)-mediated resistance to the bacterial vascular pathogen, Ralstonia solanacearum, is accompanied by cross-regulation of salicylic acid and tryptophan metabolism

    NARCIS (Netherlands)

    Denancé, N.; Ranocha, P.; Oria, N.; Barlet, X.; Rivière, M.P.; Yadeta, K.A.; Hoffmann, L.; Perreau, F.; Clément, G.; Maia-Grondard, A.; Berg, van den G.C.M.; Savelli, B.; Fournier, S.; Aubert, Y.; Pelletier, S.; Thomma, B.P.H.J.; Molina, A.; Jouanin, L.; Marco, Y.; Goffner, D.

    2013-01-01

    Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and

  20. The Mkk2 MAPKK Regulates Cell Wall Biogenesis in Cooperation with the Cek1-Pathway in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Elvira Román

    Full Text Available The cell wall integrity pathway (CWI plays an important role in the biogenesis of the cell wall in Candida albicans and other fungi. In the present work, the C. albicans MKK2 gene that encodes the putative MAPKK of this pathway was deleted in different backgrounds and the phenotypes of the resultant mutants were characterised. We show here that Mkk2 mediates the phosphorylation of the Mkc1 MAPK in response to cell wall assembly interfering agents such as zymolyase or tunicamycin and also to oxidative stress. Remarkably, mkk2 and mkc1 mutants display related but distinguishable- cell wall associated phenotypes and differ in the pattern of MAPK phosphorylation under different stress conditions. mkk2 and mkc1 mutants display an altered expression of GSC1, CEK1 and CRH11 genes at different temperatures. Combined deletion of MKK2 with HST7 supports a cooperative role for the Cek1-mediated and CWI pathways in regulating cell wall architecture under vegetative growth. However, and in contrast to Mkc1, Mkk2 does not seem to play a role in the virulence of C. albicans in the mouse systemic model or the Galleria mellonella model of infection.

  1. On the developmental and environmental regulation of secondary metabolism in Vaccinium spp. berries

    Directory of Open Access Journals (Sweden)

    Katja eKarppinen

    2016-05-01

    Full Text Available Secondary metabolites have important defense and signaling roles, and they contribute to the overall quality of developing and ripening fruits. Blueberries, bilberries, cranberries and other Vaccinium berries are fleshy berry fruits recognized for the high levels of bioactive compounds, especially anthocyanin pigments. Besides anthocyanins and other products of the phenylpropanoid and flavonoid pathways, these berries also contain other metabolites of interest, such as carotenoid derivatives, vitamins and flavor compounds. Recently, new information has been achieved on the mechanisms related with developmental, environmental and genetic factors involved in the regulation of secondary metabolism in Vaccinium fruits. Especially light conditions and temperature are demonstrated to have a prominent role on the composition of phenolic compounds. The present review focuses on the studies on mechanisms associated with the regulation of key secondary metabolites, mainly phenolic compounds, in Vaccinium berries. The advances in the research concerning biosynthesis of phenolic compounds in Vaccinium species, including specific studies with mutant genotypes in addition to controlled and field experiments on the genotype x environment (GxE interaction, are discussed. The recently published Vaccinium transcriptome and genome databases provide new tools for the studies on the metabolic routes.

  2. Outside-in control -Does plant cell wall integrity regulate cell cycle progression?

    Science.gov (United States)

    Gigli-Bisceglia, Nora; Hamann, Thorsten

    2018-04-13

    During recent years it has become accepted that plant cell walls are not inert objects surrounding all plant cells but are instead highly dynamic, plastic structures. They are involved in a large number of cell biological processes and contribute actively to plant growth, development and interaction with environment. Therefore, it is not surprising that cellular processes can control plant cell wall integrity while, simultaneously, cell wall integrity can influence cellular processes. In yeast and animal cells such a bi-directional relationship also exists between the yeast/animal extra-cellular matrices and the cell cycle. In yeast, the cell wall integrity maintenance mechanism and a dedicated plasmamembrane integrity checkpoint are mediating this relationship. Recent research has yielded insights into the mechanism controlling plant cell wall metabolism during cytokinesis. However, knowledge regarding putative regulatory pathways controlling adaptive modifications in plant cell cycle activity in response to changes in the state of the plant cell wall are not yet identified. In this review, we summarize similarities and differences in regulatory mechanisms coordinating extra cellular matrices and cell cycle activity in animal and yeast cells, discuss the available evidence supporting the existence of such a mechanism in plants and suggest that the plant cell wall integrity maintenance mechanism might also control cell cycle activity in plant cells. This article is protected by copyright. All rights reserved.

  3. Histone acetylation associated up-regulation of the cell wall related genes is involved in salt stress induced maize root swelling

    OpenAIRE

    Li, Hui; Yan, Shihan; Zhao, Lin; Tan, Junjun; Zhang, Qi; Gao, Fei; Wang, Pu; Hou, Haoli; Li, Lijia

    2014-01-01

    Background Salt stress usually causes crop growth inhibition and yield decrease. Epigenetic regulation is involved in plant responses to environmental stimuli. The epigenetic regulation of the cell wall related genes associated with the salt-induced cellular response is still little known. This study aimed to analyze cell morphological alterations in maize roots as a consequence of excess salinity in relation to the transcriptional and epigenetic regulation of the cell wall related protein ge...

  4. RGM regulates BMP-mediated secondary axis formation in the sea anemone Nematostella vectensis.

    Science.gov (United States)

    Leclère, Lucas; Rentzsch, Fabian

    2014-12-11

    Patterning of the metazoan dorsoventral axis is mediated by a complex interplay of BMP signaling regulators. Repulsive guidance molecule (RGM) is a conserved BMP coreceptor that has not been implicated in axis specification. We show that NvRGM is a key positive regulator of BMP signaling during secondary axis establishment in the cnidarian Nematostella vectensis. NvRGM regulates first the generation and later the shape of a BMP-dependent Smad1/5/8 gradient with peak activity on the side opposite the NvBMP/NvRGM/NvChordin expression domain. Full knockdown of Smad1/5/8 signaling blocks the formation of endodermal structures, the mesenteries, and the establishment of bilateral symmetry, while altering the gradient through partial NvRGM or NvBMP knockdown shifts the boundaries of asymmetric gene expression and the positioning of the mesenteries along the secondary axis. These findings provide insight into the diversification of axis specification mechanisms and identify a previously unrecognized role for RGM in BMP-mediated axial patterning. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  5. The role of beneficial bacteria wall elasticity in regulating innate immune response

    OpenAIRE

    ?okrozub, Viktoria V.; Lazarenko, Liudmyla M.; Sichel, Liubov M.; Babenko, Lidia P.; Lytvyn, Petro M.; Demchenko, Olga M.; Melnichenko, Yulia O.; Boyko, Nadiya V.; Biavati, Bruno; DiGioia, Diana; Bubnov, Rostyslav V.; Spivak, Mykola Ya

    2015-01-01

    Background Probiotics have great potential to contribute to development of healthy dietary regimes, preventive care, and an integrated approach to immunity-related disease management. The bacterial wall is a dynamic entity, depending on many components and playing an essential role in modulating immune response. The impact of cell wall elasticity on the beneficial effects of probiotic strains has not been sufficiently studied. The aim was to investigate the effect of lactic acid bacteria (LAB...

  6. Advanced sclerosis of the chest wall skin secondary to chronic graft-versus-host disease: a case with severe restrictive lung defect.

    Science.gov (United States)

    Ödek, Çağlar; Kendirli, Tanil; İleri, Talia; Yaman, Ayhan; Fatih Çakmakli, Hasan; Ince, Elif; İnce, Erdal; Ertem, Mehmet

    2014-10-01

    Pulmonary chronic graft-versus-host disease (cGvHD) is one of the most common causes of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (aHSCT). Herein, we describe a patient with severe restrictive lung defect secondary to cGvHD. A 21-year-old male patient was admitted to our pediatric intensive care unit (PICU) with pneumonia and respiratory distress. He had a history of aHSCT for chronic myelogeneous leukemia at the age of 17 years. Six months after undergoing aHSCT, he had developed cGvHD involving skin, mouth, eye, lung, liver, and gastrointestinal tract. At the time of PICU admission he had respiratory distress and required ventilation support. Thorax high-resolution computed tomography was consistent with bronchiolitis obliterans. Although bronchiolitis obliterans is an obstructive lung defect, a restrictive pattern became prominent in the clinical course because of the sclerotic chest wall skin. The activity of cGvHD kept increasing despite the therapy and we lost the patient because of severe respiratory distress and massive hemoptysis secondary to bronchiectasis. In conclusion, pulmonary cGvHD can present with restrictive changes related with the advanced sclerosis of the chest wall skin. Performing a fasciotomy or a scar revision for the rigid chest wall in selected patients may improve the patients ventilation.

  7. Self-Regulation and the Effects of an Educational Intervention in Secondary Education

    Directory of Open Access Journals (Sweden)

    Rosa María Osés Bargas

    2014-04-01

    Full Text Available The purpose of this paper was to foster the first grade students’ self-regulatory learning skills in a public elemental secondary school through an educational intervention program that allows them to acquire effective study skills to improve academic performance. The whole population of first grade (226 classified into six classrooms labeled from A to F was participated. The Flores and Cerino (2000 Self-regulation Questionnaire was used. It was an applied research with a time series design with static groups (Mertens, 2005. The outcomes show that the educational intervention program had an impact only on support and meta-cognitive factors in classroom A, and on the cognitive factor in classrooms A and D. In conclusion, it is important to point out the professors’ meaningful role in teaching these processes as well as the use of other methods to assess the development of the sel-regulation processes.

  8. The role of beneficial bacteria wall elasticity in regulating innate immune response.

    Science.gov (United States)

    Мokrozub, Viktoria V; Lazarenko, Liudmyla M; Sichel, Liubov M; Babenko, Lidia P; Lytvyn, Petro M; Demchenko, Olga M; Melnichenko, Yulia O; Boyko, Nadiya V; Biavati, Bruno; DiGioia, Diana; Bubnov, Rostyslav V; Spivak, Mykola Ya

    2015-01-01

    Probiotics have great potential to contribute to development of healthy dietary regimes, preventive care, and an integrated approach to immunity-related disease management. The bacterial wall is a dynamic entity, depending on many components and playing an essential role in modulating immune response. The impact of cell wall elasticity on the beneficial effects of probiotic strains has not been sufficiently studied. The aim was to investigate the effect of lactic acid bacteria (LAB) and bifidobacteria strains on phagocytic system cells (macrophages) as related to bacterial wall elasticity, estimated using atomic force microscopy (AFM). We conducted studies on Balb/c line mice 18-20 g in weight using lyophilized strains of LAB-Lactobacillus acidophilus IMV B-7279, Lactobacillus casei IMV B-7280, Lactobacillus delbrueckii subsp. bulgaricus IMV B-7281, and bifidobacteria-Bifidobacterium animalis VKL and Bifidobacterium animalis VKB. We cultivated the macrophages obtained from the peritoneal cavity of mice individually with the strains of LAB and bifidobacteria and evaluated their effect on macrophages, oxygen-dependent bactericidal activity, nitric oxide production, and immunoregulatory cytokines. We used AFM scanning to estimate bacterial cell wall elasticity. All strains had a stimulating effect on the functional activity of macrophages and ability to produce NO/NO2 in vitro. Lactobacilli strains increased the production of IL-12 and IFN-γ in vitro. The AFM demonstrated different cell wall elasticity levels in various strains of LAB and bifidobacteria. The rigidity of the cell walls among lactobacilli was distributed as follows: Lactobacillus acidophilus IMV B-7279 > Lactobacillus casei IMV B-7280 > Lactobacillus delbrueckii subsp. bulgaricus IMV B-7281; among the strains of bifidobacteria: B. animalis VKB > B. animalis VKL. Probiotic strain survival in the macrophages depended on the bacterial cell wall elasticity and on the time of their joint cultivation. LAB

  9. Influence of Wall-Current-Compensation and Secondary-Electron-Emission on the Plasma Parameters and on the Performance of Electron Cyclotron Resonance Ion Sources

    International Nuclear Information System (INIS)

    Schachter, L.; Dobrescu, S.; Stiebing, K.E.

    2005-01-01

    Axial and radial diffusion processes determine the confinement time in an ECRIS. It has been demonstrated that a biased disk redirects the ion- and electron currents in the source in such a way that the source performance is improved. This effect is due to a partial cancellation of the compensating currents in the conductive walls of the plasma chamber.In this contribution we present an experiment, where these currents were effectively suppressed by using a metal-dielectric (MD) disk instead of the standard metallic disk in the Frankfurt 14-GHz-ECRIS. Lower values of the plasma potential and higher average charge states in the presence of the MD disk as compared to the case of the standard disk indicate that, due to the insulating properties of its dielectric layer the MD disk obviously blocks compensating wall currents better than applying bias to the metallic standard disk.A comparison with results from experiments with a MD liner in the source, covering essentially the complete radial walls of the plasma chamber, clearly demonstrates that the beneficial effect of the liner on the performance of the ECRIS is much stronger than that observed with the MD-disk. In accord with our earlier interpretation, it has to be concluded that the 'liner-effect' is not just the effect of blocking the compensating wall currents but rather has to be ascribed to the unique property of the thin MD liner as a strong secondary electron emitter under bombardment by charged particles

  10. Blend-wall economics. Relaxing US ethanol regulations can lead to increased use of fossil fuels

    International Nuclear Information System (INIS)

    Zhang, Zibin; Qiu, Cheng; Wetzstein, Michael

    2010-01-01

    The US Environmental Protection Agency is currently considering a waiver allowing an increase in the fuel-ethanol blend limit (the 'blend wall') from 10% (E10) up to 15% (E15). Justifications for this waiver are reduced vehicle fuel prices and less consumption of petroleum gasoline leading to energy security. A theoretical examination of this waiver reveals an anomaly where a relaxation of this blend wall elicits a demand response. Under a wide range of elasticities, this demand response can actually increase the consumption of petroleum gasoline and thus lead to greater energy insecurity. The economics supporting this result and associated policy implications are developed and discussed. (author)

  11. Blend-wall economics. Relaxing US ethanol regulations can lead to increased use of fossil fuels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zibin [Department of Economics at Zhejiang University, Hangzhou (China); Qiu, Cheng; Wetzstein, Michael [Department of Agricultural and Applied Economics, University of Georgia, Athens, Georgia 30602 (United States)

    2010-07-15

    The US Environmental Protection Agency is currently considering a waiver allowing an increase in the fuel-ethanol blend limit (the 'blend wall') from 10% (E10) up to 15% (E15). Justifications for this waiver are reduced vehicle fuel prices and less consumption of petroleum gasoline leading to energy security. A theoretical examination of this waiver reveals an anomaly where a relaxation of this blend wall elicits a demand response. Under a wide range of elasticities, this demand response can actually increase the consumption of petroleum gasoline and thus lead to greater energy insecurity. The economics supporting this result and associated policy implications are developed and discussed. (author)

  12. The veA gene of the pine needle pathogen Dothistroma septosporum regulates sporulation and secondary metabolism

    Science.gov (United States)

    Fungi possess genetic systems to regulate the expression of genes involved in complex processes such as development and secondary metabolite biosynthesis. The product of the velvet gene veA, first identified and characterized in Aspergillus nidulans, is a key player in the regulation of both of thes...

  13. The Emotional Resources Group: Provisional outcome data for a pilot six-session emotion regulation programme for secondary care.

    Science.gov (United States)

    Bacon, Thomas; Doughty, Caitriona; Summers, Andrew; Wiffen, Benjamin; Stanley, Zoe; McAlpine, Susan

    2018-06-01

    To examine the effectiveness of a new, six-session emotion regulation group intervention designed for the secondary care setting: The Emotional Resources Group (ERG). In this pilot study, participants were recruited by referral from secondary care mental health services. Forty-seven individuals participated in the study. Participants who attended the ERG were compared on measures of emotion regulation, well-being, and self-efficacy, pre- and post-intervention. Intent-to-treat analyses indicated highly statistically significant improvements in measures of emotion regulation, well-being, and self-efficacy, accompanied by large effect sizes. In addition, improvements in emotion regulation produced good rates of both reliable and clinically significant change. The ERG may be an effective, brief intervention to improve emotion regulation in the secondary care setting, worthy of further evaluation. Clinical implications Emotion regulation may be an appropriate treatment target to improve well-being and self-efficacy in a transdiagnostic population. The ERG may be effective as a brief emotion regulation intervention for secondary care mental health settings. Outcomes of the ERG appear to be equivalent to other more intensive group-based emotion regulation interventions. The ERG's tailored design may be responsible for positive outcomes. Limitations There was a small sample size. There was no control group. There was no follow-up data. © 2018 The British Psychological Society.

  14. Physiology, regulation and multifunctional activity of the gut wall: a rationale for multicompartmental modelling

    NARCIS (Netherlands)

    Bannink, A.; Dijkstra, J.; Koopmans, S.J.; Mroz, Z.

    2006-01-01

    A rationale is given for a modelling approach to identify the mechanisms involved in the functioning and metabolic activity of tissues in the wall of the gastrointestinal tract. Maintenance and productive functions are discussed and related to the distinct compartments of the gastrointestinal tract

  15. Abdominal wall hernia and aortic injury secondary to blunt trauma: Case report and review of the literature

    Directory of Open Access Journals (Sweden)

    David H. Ballard

    2014-01-01

    CONCLUSION: The patient with blunt trauma to the abdomen is at risk for TAWH and TAAI, which are often associated with other injuries. Investigations should include thorough clinical exam through secondary survey and radiologic imaging in the hemodynamically normal patient.

  16. Wind farms providing secondary frequency regulation: Evaluating the performance of model-based receding horizon control

    International Nuclear Information System (INIS)

    Shapiro, Carl R.; Meneveau, Charles; Gayme, Dennice F.; Meyers, Johan

    2016-01-01

    We investigate the use of wind farms to provide secondary frequency regulation for a power grid. Our approach uses model-based receding horizon control of a wind farm that is tested using a large eddy simulation (LES) framework. In order to enable real-time implementation, the control actions are computed based on a time-varying one-dimensional wake model. This model describes wake advection and interactions, both of which play an important role in wind farm power production. This controller is implemented in an LES model of an 84-turbine wind farm represented by actuator disk turbine models. Differences between the velocities at each turbine predicted by the wake model and measured in LES are used for closed-loop feedback. The controller is tested on two types of regulation signals, “RegA” and “RegD”, obtained from PJM, an independent system operator in the eastern United States. Composite performance scores, which are used by PJM to qualify plants for regulation, are used to evaluate the performance of the controlled wind farm. Our results demonstrate that the controlled wind farm consistently performs well, passing the qualification threshold for all fastacting RegD signals. For the RegA signal, which changes over slower time scales, the controlled wind farm's average performance surpasses the threshold, but further work is needed to enable the controlled system to achieve qualifying performance all of the time. (paper)

  17. Na,K-ATPase regulates intercellular communication in the vascular wall via cSrc kinase dependent connexin43 phosphorylation

    DEFF Research Database (Denmark)

    Hangaard, Lise; Bouzinova, Elena; Stæhr, Christian Albeck

    2017-01-01

    Communication between vascular smooth muscle cells (VSMCs) is dependent on gap junctions and is regulated by the Na-K-ATPase. The Na-K-ATPase is therefore important for synchronized VSMC oscillatory activity, i.e., vasomotion. The signaling between the Na-K-ATPase and gap junctions is unknown. We...... coupling in rat mesenteric small arteries in vitro. Phosphorylation of cSrc kinase and connexin43 (Cx43) were semiquantified by Western blotting. Micromole concentration of ouabain reduced the amplitude of norepinephrine-induced vasomotion and desynchronized Ca2+ transients in VSMC in the arterial wall...

  18. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 2: Assessing the influence of vapor wall losses

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2016-03-01

    Full Text Available The influence of losses of organic vapors to chamber walls during secondary organic aerosol (SOA formation experiments has recently been established. Here, the influence of such losses on simulated ambient SOA concentrations and properties is assessed in the University of California at Davis / California Institute of Technology (UCD/CIT regional air quality model using the statistical oxidation model (SOM for SOA. The SOM was fit to laboratory chamber data both with and without accounting for vapor wall losses following the approach of Zhang et al. (2014. Two vapor wall-loss scenarios are considered when fitting of SOM to chamber data to determine best-fit SOM parameters, one with “low” and one with “high” vapor wall-loss rates to approximately account for the current range of uncertainty in this process. Simulations were run using these different parameterizations (scenarios for both the southern California/South Coast Air Basin (SoCAB and the eastern United States (US. Accounting for vapor wall losses leads to substantial increases in the simulated SOA concentrations from volatile organic compounds (VOCs in both domains, by factors of  ∼  2–5 for the low and  ∼  5–10 for the high scenarios. The magnitude of the increase scales approximately inversely with the absolute SOA concentration of the no loss scenario. In SoCAB, the predicted SOA fraction of total organic aerosol (OA increases from  ∼  0.2 (no to  ∼  0.5 (low and to  ∼  0.7 (high, with the high vapor wall-loss simulations providing best general agreement with observations. In the eastern US, the SOA fraction is large in all cases but increases further when vapor wall losses are accounted for. The total OA ∕ ΔCO ratio captures the influence of dilution on SOA concentrations. The simulated OA ∕ ΔCO in SoCAB (specifically, at Riverside, CA is found to increase substantially during the day only for the high vapor wall

  19. Matrix Metalloproteinase 9 (MMP-9 Regulates Vein Wall Biomechanics in Murine Thrombus Resolution.

    Directory of Open Access Journals (Sweden)

    Khanh P Nguyen

    Full Text Available Deep venous thrombosis is a common vascular problem with long-term complications including post-thrombotic syndrome. Post-thrombotic syndrome consists of leg pain, swelling and ulceration that is related to incomplete or maladaptive resolution of the venous thrombus as well as loss of compliance of the vein wall. We examine the role of metalloproteinase-9 (MMP-9, a gene important in extracellular remodeling in other vascular diseases, in mediating thrombus resolution and biomechanical changes of the vein wall.The effects of targeted deletion of MMP-9 were studied in an in vivo murine model of thrombus resolution using the FVB strain of mice. MMP-9 expression and activity significantly increased on day 3 after DVT. The lack of MMP-9 impaired thrombus resolution by 27% and this phenotype was rescued by the transplantation of wildtype bone marrow cells. Using novel biomechanical techniques, we demonstrated that the lack of MMP-9 significantly decreased thrombus-induced loss of vein wall compliance. Biomechanical analysis of the contribution of individual structural components showed that MMP-9 affected the elasticity of the extracellular matrix and collagen-elastin fibers. Biochemical and histological analyses correlated with these biomechanical effects as thrombi of mice lacking MMP-9 had significantly fewer macrophages and collagen as compared to those of wildtype mice.MMP-9 mediates thrombus-induced loss of vein wall compliance by increasing stiffness of the extracellular matrix and collagen-elastin fibers during thrombus resolution. MMP-9 also mediates macrophage and collagen content of the resolving thrombus and bone-marrow derived MMP-9 plays a role in resolution of thrombus mass. These disparate effects of MMP-9 on various aspects of thrombus illustrate the complexity of individual protease function on biomechanical and morphometric aspects of thrombus resolution.

  20. Matrix Metalloproteinase 9 (MMP-9) Regulates Vein Wall Biomechanics in Murine Thrombus Resolution

    Science.gov (United States)

    Nguyen, Khanh P.; McGilvray, Kirk C.; Puttlitz, Christian M.; Mukhopadhyay, Subhradip; Chabasse, Christine; Sarkar, Rajabrata

    2015-01-01

    Objective Deep venous thrombosis is a common vascular problem with long-term complications including post-thrombotic syndrome. Post-thrombotic syndrome consists of leg pain, swelling and ulceration that is related to incomplete or maladaptive resolution of the venous thrombus as well as loss of compliance of the vein wall. We examine the role of metalloproteinase-9 (MMP-9), a gene important in extracellular remodeling in other vascular diseases, in mediating thrombus resolution and biomechanical changes of the vein wall. Methods and Results The effects of targeted deletion of MMP-9 were studied in an in vivo murine model of thrombus resolution using the FVB strain of mice. MMP-9 expression and activity significantly increased on day 3 after DVT. The lack of MMP-9 impaired thrombus resolution by 27% and this phenotype was rescued by the transplantation of wildtype bone marrow cells. Using novel biomechanical techniques, we demonstrated that the lack of MMP-9 significantly decreased thrombus-induced loss of vein wall compliance. Biomechanical analysis of the contribution of individual structural components showed that MMP-9 affected the elasticity of the extracellular matrix and collagen-elastin fibers. Biochemical and histological analyses correlated with these biomechanical effects as thrombi of mice lacking MMP-9 had significantly fewer macrophages and collagen as compared to those of wildtype mice. Conclusions MMP-9 mediates thrombus-induced loss of vein wall compliance by increasing stiffness of the extracellular matrix and collagen-elastin fibers during thrombus resolution. MMP-9 also mediates macrophage and collagen content of the resolving thrombus and bone-marrow derived MMP-9 plays a role in resolution of thrombus mass. These disparate effects of MMP-9 on various aspects of thrombus illustrate the complexity of individual protease function on biomechanical and morphometric aspects of thrombus resolution. PMID:26406902

  1. Modeling of a New Structure of Precision Air Conditioning System Using Secondary Condenser for Rh Regulation

    Directory of Open Access Journals (Sweden)

    Aries Subiantoro

    2012-05-01

    Full Text Available A dynamic mathematical model for a new structure of precision air conditioning (PAC has been developed. The proposed PAC uses an additional secondary condenser for relative humidity regulation compared to a basic refrigeration system. The work mechanism for this system and a vapour-compression cycle process of the system are illustrated using psychrometric chart and pressure-enthalpy diagram. A non-linear system model is derived based on the conservation of mass and energy balance principles and then linearized at steady state operating point for developing a 8th-order state space model suited for multivariable controller design. The quality of linearized model is analyzed in terms of transient response, controllability, observability, and interaction between input-output variables. The developed model is verified through simulation showing its ability for imitating the nonlinear behavior and the interaction of input-output variables.

  2. Let-7 and MicroRNA-148 Regulate Parathyroid Hormone Levels in Secondary Hyperparathyroidism.

    Science.gov (United States)

    Shilo, Vitali; Mor-Yosef Levi, Irit; Abel, Roy; Mihailović, Aleksandra; Wasserman, Gilad; Naveh-Many, Tally; Ben-Dov, Iddo Z

    2017-08-01

    Secondary hyperparathyroidism commonly complicates CKD and associates with morbidity and mortality. We profiled microRNA (miRNA) in parathyroid glands from experimental hyperparathyroidism models and patients receiving dialysis and studied the function of specific miRNAs. miRNA deep-sequencing showed that human and rodent parathyroids share similar profiles. Parathyroids from uremic and normal rats segregated on the basis of their miRNA expression profiles, and a similar finding was observed in humans. We identified parathyroid miRNAs that were dysregulated in experimental hyperparathyroidism, including miR-29, miR-21, miR-148, miR-30, and miR-141 (upregulated); and miR-10, miR-125, and miR-25 (downregulated). Inhibition of the abundant let-7 family increased parathyroid hormone (PTH) secretion in normal and uremic rats, as well as in mouse parathyroid organ cultures. Conversely, inhibition of the upregulated miR-148 family prevented the increase in serum PTH level in uremic rats and decreased levels of secreted PTH in parathyroid cultures. The evolutionary conservation of abundant miRNAs in normal parathyroid glands and the regulation of these miRNAs in secondary hyperparathyroidism indicates their importance for parathyroid function and the development of hyperparathyroidism. Specifically, let-7 and miR-148 antagonism modified PTH secretion in vivo and in vitro , implying roles for these specific miRNAs. These findings may be utilized for therapeutic interventions aimed at altering PTH expression in diseases such as osteoporosis and secondary hyperparathyroidism. Copyright © 2017 by the American Society of Nephrology.

  3. 3x2 Classroom Goal Structures, Motivational Regulations, Self-Concept, and Affectivity in Secondary School.

    Science.gov (United States)

    Méndez-Giménez, Antonio; Cecchini-Estrada, José-Antonio; Fernández-Río, Javier; Prieto Saborit, José Antonio; Méndez-Alonso, David

    2017-09-20

    The main objective was to analyze relationships and predictive patterns between 3x2 classroom goal structures (CGS), and motivational regulations, dimensions of self-concept, and affectivity in the context of secondary education. A sample of 1,347 secondary school students (56.6% young men, 43.4% young women) from 10 different provinces of Spain agreed to participate (M age = 13.43, SD = 1.05). Hierarchical regression analyses indicated the self-approach CGS was the most adaptive within the spectrum of self-determination, followed by the task-approach CGS. The other-approach CGS had an ambivalent influence on motivation. Task-approach and self-approach CGS predicted academic self-concept (p approach CGS (negatively) predicted family self-concept (p approach and other-approach CGS's (p approach-oriented CGS's (p approach (positively) and self-approach (negatively) CGS (p < .001; p < .05, respectively; R 2 = .028). These results expand the 3x2 achievement goal framework to include environmental factors, and reiterate that teachers should focus on raising levels of self- and task-based goals for students in their classes.

  4. Isolation and characterization of beta-glucan synthase: A potential biochemical regulator of gravistimulated differential cell wall loosening

    Science.gov (United States)

    Kuzmanoff, K. M.

    1984-01-01

    In plants, gravity stimulates differential growth in the upper and lower halves of horizontally oriented organs. Auxin regulation of cell wall loosening and elongation is the basis for most models of this phenomenon. Auxin treatment of pea stem tissue rapidly increases the activity of Golgi-localized Beta-1,4-glucan synthase, an enzyme involved in biosynthesis of wall xyloglucan which apparently constitutes the substrate for the wall loosening process. The primary objective is to determine if auxin induces de novo formation of Golgi glucan synthase and increases the level of this glucan synthase mRNA. This shall be accomplished by (a) preparation of a monoclonal antibody to the synthase, (b) isolation, and characterization of the glucan synthase, and (c) examination for cross reactivity between the antibody and translation products of auxin induced mRNAs in pea tissue. The antibody will also be used to localize the glucan synthase in upper and lower halves of pea stem tissue before, during and after the response to gravity.

  5. The effect of self-regulated strategy instruction and behavioral consultation on motivation : A longitudinal study on the effect of school-based interventions in secondary education.

    NARCIS (Netherlands)

    Minnaert, Alexander; Prince, Arnout; Opdenakker, Marie

    2017-01-01

    Studies show a decrease in students’ motivation in secondary education. Hence, it was investigated whether training of teachers could stop this decline. Two interventions were implemented in prevocational secondary education, being self-regulated strategy instruction and behavioral consultation

  6. Calcium-dependent depletion zones in the cortical microtubule array coincide with sites of, but do not regulate, wall ingrowth papillae deposition in epidermal transfer cells

    Science.gov (United States)

    Zhang, Hui-ming; Talbot, Mark J.; McCurdy, David W.; Patrick, John W.; Offler, Christina E.

    2015-01-01

    Trans-differentiation to a transfer-cell morphology is characterized by the localized deposition of wall ingrowth papillae that protrude into the cytosol. Whether the cortical microtubule array directs wall ingrowth papillae formation was investigated using a Vicia faba cotyledon culture system in which their adaxial epidermal cells were spontaneously induced to trans-differentiate to transfer cells. During deposition of wall ingrowth papillae, the aligned cortical microtubule arrays in precursor epidermal cells were reorganized into a randomized array characterized by circular depletion zones. Concurrence of the temporal appearance, spatial pattern, and size of depletion zones and wall ingrowth papillae was consistent with each papilla occupying a depletion zone. Surprisingly, microtubules appeared not to regulate construction of wall ingrowth papillae, as neither depolymerization nor stabilization of cortical microtubules changed their deposition pattern or morphology. Moreover, the size and spatial pattern of depletion zones was unaltered when the formation of wall ingrowth papillae was blocked by inhibiting cellulose biosynthesis. In contrast, the depletion zones were absent when the cytosolic calcium plumes, responsible for directing wall ingrowth papillae formation, were blocked or dissipated. Thus, we conclude that the depletion zones within the cortical microtubule array result from localized depolymerization of microtubules initiated by elevated cytosolic Ca2+ levels at loci where wall ingrowth papillae are deposited. The physiological significance of the depletion zones as a mechanism to accommodate the construction of wall ingrowth papillae without compromising maintenance of the plasma membrane–microtubule inter-relationship is discussed. PMID:26136268

  7. Functionalization of single-walled carbon nanotubes regulates their effect on hemostasis

    International Nuclear Information System (INIS)

    Sokolov, A V; Aseychev, A V; Kostevich, V A; Gusev, A A; Gusev, S A; Vlasova, I I

    2011-01-01

    Applications of single-walled carbon nanotubes (SWNTs) in medical field imply the use of drug-coupled carbon nanotubes as well as carbon nanotubes functionalized with different chemical groups that change nanotube surface properties and interactions between nanotubes and cells. Covalent attachment of polyethylene glycol (PEG) to carboxylated single-walled carbon nanotubes (c-SWNT) is known to prevent the nanotubes from interaction with macrophages. Here we characterized nanotube's ability to stimulate coagulation processes in platelet-poor plasma (PPP), and evaluated the effect of SWNTs on platelet aggregation in platelet-rich plasma (PRP). Our study showed that PEG-SWNT did not affect the rate of clotting in PPP, while c-SWNT shortened the clot formation time five times compared to the control PPP. Since c-SWNT failed to accelerate coagulation in plasma lacking coagulation factor XI, it may be suggested that c-SWNT affects the contact activation pathway. In PRP, platelets responded to both SWNT types with irreversible aggregation, as evidenced by changes in the aggregate mean radius. However, the rate of aggregation induced by c-SWNT was two times higher than it was with PEG-SWNT. Cytological analysis also showed that c-SWNT was two times more efficient when compared to PEG-SWNT in aggregating platelets in PRP. Taken together, our results show that functionalization of nanoparticles can diminish their negative influence on blood cells. As seen from our data, modification of c-SWNT with PEG, when only a one percent of carbon atoms is bound to polymer (70 wt %), decreased the nanotube-induced coagulation in PRP and repelled the accelerating effect on the coagulation in PPP. Thus, when functionalized SWNTs are used for administration into bloodstream of laboratory animals, their possible pro-coagulant and pro-aggregating properties must be taken into account.

  8. Functionalization of single-walled carbon nanotubes regulates their effect on hemostasis

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, A V; Aseychev, A V; Kostevich, V A; Gusev, A A; Gusev, S A; Vlasova, I I, E-mail: irina.vlasova@yahoo.com [Research Institute for Physico-Chemical Medicine, FMBA, M. Pirogovskaya Str. 1a, Moscow (Russian Federation)

    2011-04-01

    Applications of single-walled carbon nanotubes (SWNTs) in medical field imply the use of drug-coupled carbon nanotubes as well as carbon nanotubes functionalized with different chemical groups that change nanotube surface properties and interactions between nanotubes and cells. Covalent attachment of polyethylene glycol (PEG) to carboxylated single-walled carbon nanotubes (c-SWNT) is known to prevent the nanotubes from interaction with macrophages. Here we characterized nanotube's ability to stimulate coagulation processes in platelet-poor plasma (PPP), and evaluated the effect of SWNTs on platelet aggregation in platelet-rich plasma (PRP). Our study showed that PEG-SWNT did not affect the rate of clotting in PPP, while c-SWNT shortened the clot formation time five times compared to the control PPP. Since c-SWNT failed to accelerate coagulation in plasma lacking coagulation factor XI, it may be suggested that c-SWNT affects the contact activation pathway. In PRP, platelets responded to both SWNT types with irreversible aggregation, as evidenced by changes in the aggregate mean radius. However, the rate of aggregation induced by c-SWNT was two times higher than it was with PEG-SWNT. Cytological analysis also showed that c-SWNT was two times more efficient when compared to PEG-SWNT in aggregating platelets in PRP. Taken together, our results show that functionalization of nanoparticles can diminish their negative influence on blood cells. As seen from our data, modification of c-SWNT with PEG, when only a one percent of carbon atoms is bound to polymer (70 wt %), decreased the nanotube-induced coagulation in PRP and repelled the accelerating effect on the coagulation in PPP. Thus, when functionalized SWNTs are used for administration into bloodstream of laboratory animals, their possible pro-coagulant and pro-aggregating properties must be taken into account.

  9. Wind farms providing secondary frequency regulation: evaluating the performance of model-based receding horizon control

    Directory of Open Access Journals (Sweden)

    C. R. Shapiro

    2018-01-01

    Full Text Available This paper is an extended version of our paper presented at the 2016 TORQUE conference (Shapiro et al., 2016. We investigate the use of wind farms to provide secondary frequency regulation for a power grid using a model-based receding horizon control framework. In order to enable real-time implementation, the control actions are computed based on a time-varying one-dimensional wake model. This model describes wake advection and wake interactions, both of which play an important role in wind farm power production. In order to test the control strategy, it is implemented in a large-eddy simulation (LES model of an 84-turbine wind farm using the actuator disk turbine representation. Rotor-averaged velocity measurements at each turbine are used to provide feedback for error correction. The importance of including the dynamics of wake advection in the underlying wake model is tested by comparing the performance of this dynamic-model control approach to a comparable static-model control approach that relies on a modified Jensen model. We compare the performance of both control approaches using two types of regulation signals, RegA and RegD, which are used by PJM, an independent system operator in the eastern United States. The poor performance of the static-model control relative to the dynamic-model control demonstrates that modeling the dynamics of wake advection is key to providing the proposed type of model-based coordinated control of large wind farms. We further explore the performance of the dynamic-model control via composite performance scores used by PJM to qualify plants for regulation services or markets. Our results demonstrate that the dynamic-model-controlled wind farm consistently performs well, passing the qualification threshold for all fast-acting RegD signals. For the RegA signal, which changes over slower timescales, the dynamic-model control leads to average performance that surpasses the qualification threshold, but further

  10. Histone acetyltransferase TGF-1 regulates Trichoderma atroviride secondary metabolism and mycoparasitism.

    Science.gov (United States)

    Gómez-Rodríguez, Elida Yazmín; Uresti-Rivera, Edith Elena; Patrón-Soberano, Olga Araceli; Islas-Osuna, María Auxiliadora; Flores-Martínez, Alberto; Riego-Ruiz, Lina; Rosales-Saavedra, María Teresa; Casas-Flores, Sergio

    2018-01-01

    Some filamentous fungi of the Trichoderma genus are used as biocontrol agents against airborne and soilborne phytopathogens. The proposed mechanism by which Trichoderma spp. antagonizes phytopathogens is through the release of lytic enzymes, antimicrobial compounds, mycoparasitism, and the induction of systemic disease-resistance in plants. Here we analyzed the role of TGF-1 (Trichoderma Gcn Five-1), a histone acetyltransferase of Trichoderma atroviride, in mycoparasitism and antibiosis against the phytopathogen Rhizoctonia solani. Trichostatin A (TSA), a histone deacetylase inhibitor that promotes histone acetylation, slightly affected T. atroviride and R. solani growth, but not the growth of the mycoparasite over R. solani. Application of TSA to the liquid medium induced synthesis of antimicrobial compounds. Expression analysis of the mycoparasitism-related genes ech-42 and prb-1, which encode an endochitinase and a proteinase, as well as the secondary metabolism-related genes pbs-1 and tps-1, which encode a peptaibol synthetase and a terpene synthase, respectively, showed that they were regulated by TSA. A T. atroviride strain harboring a deletion of tgf-1 gene showed slow growth, thinner and less branched hyphae than the wild-type strain, whereas its ability to coil around the R. solani hyphae was not affected. Δtgf-1 presented a diminished capacity to grow over R. solani, but the ability of its mycelium -free culture filtrates (MFCF) to inhibit the phytopathogen growth was enhanced. Intriguingly, addition of TSA to the culture medium reverted the enhanced inhibition growth of Δtgf-1 MFCF on R. solani at levels compared to the wild-type MFCF grown in medium amended with TSA. The presence of R. solani mycelium in the culture medium induced similar proteinase activity in a Δtgf-1 compared to the wild-type, whereas the chitinolytic activity was higher in a Δtgf-1 mutant in the absence of R. solani, compared to the parental strain. Expression of mycoparasitism

  11. Histone acetyltransferase TGF-1 regulates Trichoderma atroviride secondary metabolism and mycoparasitism.

    Directory of Open Access Journals (Sweden)

    Elida Yazmín Gómez-Rodríguez

    Full Text Available Some filamentous fungi of the Trichoderma genus are used as biocontrol agents against airborne and soilborne phytopathogens. The proposed mechanism by which Trichoderma spp. antagonizes phytopathogens is through the release of lytic enzymes, antimicrobial compounds, mycoparasitism, and the induction of systemic disease-resistance in plants. Here we analyzed the role of TGF-1 (Trichoderma Gcn Five-1, a histone acetyltransferase of Trichoderma atroviride, in mycoparasitism and antibiosis against the phytopathogen Rhizoctonia solani. Trichostatin A (TSA, a histone deacetylase inhibitor that promotes histone acetylation, slightly affected T. atroviride and R. solani growth, but not the growth of the mycoparasite over R. solani. Application of TSA to the liquid medium induced synthesis of antimicrobial compounds. Expression analysis of the mycoparasitism-related genes ech-42 and prb-1, which encode an endochitinase and a proteinase, as well as the secondary metabolism-related genes pbs-1 and tps-1, which encode a peptaibol synthetase and a terpene synthase, respectively, showed that they were regulated by TSA. A T. atroviride strain harboring a deletion of tgf-1 gene showed slow growth, thinner and less branched hyphae than the wild-type strain, whereas its ability to coil around the R. solani hyphae was not affected. Δtgf-1 presented a diminished capacity to grow over R. solani, but the ability of its mycelium -free culture filtrates (MFCF to inhibit the phytopathogen growth was enhanced. Intriguingly, addition of TSA to the culture medium reverted the enhanced inhibition growth of Δtgf-1 MFCF on R. solani at levels compared to the wild-type MFCF grown in medium amended with TSA. The presence of R. solani mycelium in the culture medium induced similar proteinase activity in a Δtgf-1 compared to the wild-type, whereas the chitinolytic activity was higher in a Δtgf-1 mutant in the absence of R. solani, compared to the parental strain. Expression

  12. In the Picture or off the Wall? Ethical Regulation, Research Habitus, and Unpeopled Ethnography

    Science.gov (United States)

    Hurdley, Rachel

    2010-01-01

    This article focuses on two unintended consequences of ethical regulation of social enquiry: the exclusion of participants and, subsequently, a transformation of research practice. An ethnography of corridor life in a large university building forms the basis of the discussion. Originally intended as a pilot for a broader study of informal…

  13. Measuring teacher regulating activities concerning student learning in secondary education classrooms : Reliability and validity of student perceptions

    NARCIS (Netherlands)

    van Beek, J. A.; de Jong, F. P. C. M.; Wubbels, Th.; Minnaert, A. E. M. G.

    2014-01-01

    This article describes the use and validation of the Pedagogical Practices Inventory, which uses student perceptions arranged into five subscales to measure teacher activities concerning the regulation of student learning in secondary education. To determine the reliability and validity of the

  14. Rubrics and Self-Assessment Scripts Effects on Self-Regulation, Learning and Self-Efficacy in Secondary Education

    Science.gov (United States)

    Panadero, Ernesto; Tapia, Jesus Alonso; Huertas, Juan Antonio

    2012-01-01

    This study compares the effects of two different self-assessment tools--rubrics and scripts--on self-regulation, learning and self-efficacy in interaction with two other independent variables (type of instructions and feedback). A total of 120 secondary school students analyzed landscapes--a usual task when studying Geography--in one of twelve…

  15. Error Detection and Self-Assessment as Mechanisms to Promote Self-Regulation of Learning among Secondary Education Students

    Science.gov (United States)

    Zamora, Ángela; Suárez, José Manuel; Ardura, Diego

    2018-01-01

    The authors' objective was to study the role of error detection and retroactive self-regulation as determinants of performance in secondary education students. A total of 198 students participated in the quasiexperimental study, which involved a control group and two experimental groups. This enabled the authors to analyze the effects of both…

  16. Actin filaments regulate the adhesion between the plasma membrane and the cell wall of tobacco guard cells.

    Science.gov (United States)

    Yu, Qin; Ren, Jing-Jing; Kong, Lan-Jing; Wang, Xiu-Ling

    2018-01-01

    During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane (PM) to the cell wall (CW). The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling. However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW. In this study, we investigated the relationship between actin dynamics and PM-CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells. We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. The inhibition of actin dynamics by treatment with latrunculin B or jasplakinolide and the disruption of the adhesion between the PM and the CW by treatment with RGDS peptide (Arg-Gly-Asp-Ser) enhanced guard cell plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis. Our results reveal that the actin depolymerization is involved in the regulation of the PW-CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells.

  17. Thermoelectric Cooling-Aided Bead Geometry Regulation in Wire and Arc-Based Additive Manufacturing of Thin-Walled Structures

    Directory of Open Access Journals (Sweden)

    Fang Li

    2018-01-01

    Full Text Available Wire and arc-based additive manufacturing (WAAM is a rapidly developing technology which employs a welding arc to melt metal wire for additive manufacturing purposes. During WAAM of thin-walled structures, as the wall height increases, the heat dissipation to the substrate is slowed down gradually and so is the solidification of the molten pool, leading to variation of the bead geometry. Though gradually reducing the heat input via adjusting the process parameters can alleviate this issue, as suggested by previous studies, it relies on experience to a large extent and inevitably sacrifices the deposition rate because the wire feed rate is directly coupled with the heat input. This study introduces for the first time an in-process active cooling system based on thermoelectric cooling technology into WAAM, which aims to eliminate the difference in heat dissipation between upper and lower layers. The case study shows that, with the aid of thermoelectric cooling, the bead width error is reduced by 56.8%, the total fabrication time is reduced by 60.9%, and the average grain size is refined by 25%. The proposed technique provides new insight into bead geometry regulation during WAAM with various benefits in terms of geometric accuracy, productivity, and microstructure.

  18. Innate Effector-Memory T-Cell Activation Regulates Post-Thrombotic Vein Wall Inflammation and Thrombus Resolution.

    Science.gov (United States)

    Luther, Natascha; Shahneh, Fatemeh; Brähler, Melanie; Krebs, Franziska; Jäckel, Sven; Subramaniam, Saravanan; Stanger, Christian; Schönfelder, Tanja; Kleis-Fischer, Bettina; Reinhardt, Christoph; Probst, Hans Christian; Wenzel, Philip; Schäfer, Katrin; Becker, Christian

    2016-12-09

    Immune cells play an important role during the generation and resolution of thrombosis. T cells are powerful regulators of immune and nonimmune cell function, however, their role in sterile inflammation in venous thrombosis has not been systematically examined. This study investigated the recruitment, activation, and inflammatory activity of T cells in deep vein thrombosis and its consequences for venous thrombus resolution. CD4 + and CD8 + T cells infiltrate the thrombus and vein wall rapidly on deep vein thrombosis induction and remain in the tissue throughout the thrombus resolution. In the vein wall, recruited T cells largely consist of effector-memory T (T EM ) cells. Using T-cell receptor transgenic reporter mice, we demonstrate that deep vein thrombosis-recruited T EM receive an immediate antigen-independent activation and produce IFN-γ (interferon) in situ. Mapping inflammatory conditions in the thrombotic vein, we identify a set of deep vein thrombosis upregulated cytokines and chemokines that synergize to induce antigen-independent IFN-γ production in CD4 + and CD8 + T EM cells. Reducing the number of T EM cells through a depletion recovery procedure, we show that intravenous T EM activation determines neutrophil and monocyte recruitment and delays thrombus neovascularization and resolution. Examining T-cell recruitment in human venous stasis, we show that superficial varicose veins preferentially contain activated memory T cells. T EM orchestrate the inflammatory response in venous thrombosis affecting thrombus resolution. © 2016 American Heart Association, Inc.

  19. FvSet2 regulates fungal growth, pathogenicity, and secondary metabolism in Fusarium verticillioides.

    Science.gov (United States)

    Gu, Qin; Wang, Zhenzhong; Sun, Xiao; Ji, Tiantian; Huang, Hai; Yang, Yang; Zhang, Hao; Tahir, Hafiz Abdul Samad; Wu, Liming; Wu, Huijun; Gao, Xuewen

    2017-10-01

    Histone H3 lysine 36 methylation (H3K36me) is generally associated with activation of gene expression in most eukaryotic cells. However, the function of H3K36me in filamentous fungi is largely unknown. Set2 is the sole lysine histone methyltransferase (KHMTase) enzyme responsible for the methylation of H3K36 in Saccharomyces cerevisiae. In the current study, we identified a single ortholog of S. cerevisiae Set2 in Fusarium verticillioides. We report that FvSet2 is responsible for the trimethylation of H3K36 (H3K36me3). The FvSET2 deletion mutant (ΔFvSet2) showed significant defects in vegetative growth, FB 1 biosynthesis, pigmentation, and fungal virulence. Furthermore, trimethylation of H3K36 was found to be important for active transcription of genes involved in FB 1 and bikaverin biosyntheses. These data indicate that FvSet2 plays an important role in the regulation of secondary metabolism, vegetative growth and fungal virulence in F. verticillioides. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Naringenin Regulates Expression of Genes Involved in Cell Wall Synthesis in Herbaspirillum seropedicae▿

    Science.gov (United States)

    Tadra-Sfeir, M. Z.; Souza, E. M.; Faoro, H.; Müller-Santos, M.; Baura, V. A.; Tuleski, T. R.; Rigo, L. U.; Yates, M. G.; Wassem, R.; Pedrosa, F. O.; Monteiro, R. A.

    2011-01-01

    Five thousand mutants of Herbaspirillum seropedicae SmR1 carrying random insertions of transposon pTnMod-OGmKmlacZ were screened for differential expression of LacZ in the presence of naringenin. Among the 16 mutants whose expression was regulated by naringenin were genes predicted to be involved in the synthesis of exopolysaccharides, lipopolysaccharides, and auxin. These loci are probably involved in establishing interactions with host plants. PMID:21257805

  1. Naringenin regulates expression of genes involved in cell wall synthesis in Herbaspirillum seropedicae.

    Science.gov (United States)

    Tadra-Sfeir, M Z; Souza, E M; Faoro, H; Müller-Santos, M; Baura, V A; Tuleski, T R; Rigo, L U; Yates, M G; Wassem, R; Pedrosa, F O; Monteiro, R A

    2011-03-01

    Five thousand mutants of Herbaspirillum seropedicae SmR1 carrying random insertions of transposon pTnMod-OGmKmlacZ were screened for differential expression of LacZ in the presence of naringenin. Among the 16 mutants whose expression was regulated by naringenin were genes predicted to be involved in the synthesis of exopolysaccharides, lipopolysaccharides, and auxin. These loci are probably involved in establishing interactions with host plants.

  2. Turmeric (Curcuma longa): miRNAs and their regulating targets are involved in development and secondary metabolite pathways.

    Science.gov (United States)

    Singh, Noopur; Sharma, Ashok

    Turmeric has been used as a therapeutic herb over centuries in traditional medicinal systems due to the presence of several secondary metabolite compounds. microRNAs are known to regulate gene expression at the post-transcriptional level by transcriptional cleavage or translation repression. miRNAs have been demonstrated to play an active role in secondary metabolism regulation. The present work was focused on the identification of the miRNAs involved in the regulation of secondary metabolite and development process of turmeric. Eighteen miRNA families were identified for turmeric. Sixteen miRNA families were observed to regulate 238 target transcripts. LncRNAs targets of the putative miRNA candidates were also predicted. Our results indicated their role in binding, reproduction, stress, and other developmental processes. Gene annotation and pathway analysis illustrated the biological function of the targets regulated by the putative miRNAs. The miRNA-mediated gene regulatory network also revealed co-regulated targets that were regulated by two or more miRNA families. miR156 and miR5015 were observed to be involved in rhizome development. miR5021 showed regulation for terpenoid backbone biosynthesis and isoquinoline alkaloid biosynthesis pathways. The flavonoid biosynthesis pathway was observed to be regulated by miR2919. The analysis revealed the probable involvement of three miRNAs (miR1168.2, miR156b and miR1858) in curcumin biosynthesis. Other miRNAs were found to be involved in the growth and developmental process of turmeric. Phylogenetic analysis of selective miRNAs was also performed. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  3. Dynamics of chest wall volume regulation during constant work rate exercise in patients with chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Takara, L.S.; Cunha, T.M.; Barbosa, P.; Rodrigues, M.K.; Oliveira, M.F.; Nery, L.E. [Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Disciplina de Pneumologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Neder, J.A. [Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Disciplina de Pneumologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen' s University, Kingston, ON (Canada)

    2012-10-15

    This study evaluated the dynamic behavior of total and compartmental chest wall volumes [(V{sub CW}) = rib cage (V{sub RC}) + abdomen (V{sub AB})] as measured breath-by-breath by optoelectronic plethysmography during constant-load exercise in patients with stable chronic obstructive pulmonary disease. Thirty males (GOLD stages II-III) underwent a cardiopulmonary exercise test to the limit of tolerance (Tlim) at 75% of peak work rate on an electronically braked cycle ergometer. Exercise-induced dynamic hyperinflation was considered to be present when end-expiratory (EE) V{sub CW} increased in relation to resting values. There was a noticeable heterogeneity in the patterns of V{sub CW} regulation as EEV{sub CW} increased non-linearly in 17/30 “hyperinflators” and decreased in 13/30 “non-hyperinflators” (P < 0.05). EEV{sub AB} decreased slightly in 8 of the “hyperinflators”, thereby reducing and slowing the rate of increase in end-inspiratory (EI) V{sub CW} (P < 0.05). In contrast, decreases in EEV{sub CW} in the “non-hyperinflators” were due to the combination of stable EEV{sub RC} with marked reductions in EEV{sub AB}. These patients showed lower EIV{sub CW} and end-exercise dyspnea scores but longer Tlim than their counterparts (P < 0.05). Dyspnea increased and Tlim decreased non-linearly with a faster rate of increase in EIV{sub CW} regardless of the presence or absence of dynamic hyperinflation (P < 0.001). However, no significant between-group differences were observed in metabolic, pulmonary gas exchange and cardiovascular responses to exercise. Chest wall volumes are continuously regulated during exercise in order to postpone (or even avoid) their migration to higher operating volumes in patients with COPD, a dynamic process that is strongly dependent on the behavior of the abdominal compartment.

  4. In vivo translocation and toxicity of multi-walled carbon nanotubes are regulated by microRNAs

    Science.gov (United States)

    Zhao, Yunli; Wu, Qiuli; Li, Yiping; Nouara, Abdelli; Jia, Ruhan; Wang, Dayong

    2014-03-01

    We employed an in vivo Caenorhabditis elegans assay system to perform SOLiD sequencing analysis to identify the possible microRNA (miRNA) targets of multi-walled carbon nanotubes (MWCNTs). Bioinformatics analysis on targeted genes for the identified dysregulated miRNAs in MWCNT exposed nematodes demonstrates their involvement in many aspects of biological processes. We used loss-of-function mutants for the identified dysregulated miRNAs to perform toxicity assessment by evaluating functions of primary and secondary targeted organs, and found the miRNA mutants with susceptible or resistant property towards MWCNT toxicity. Both the physiological state of the intestine and defecation behavior were involved in the control of the susceptible or resistant property occurrence for specific miRNA mutants towards MWCNT toxicity. This work provides the molecular basis at the miRNA level for future chemical design to reduce the nanotoxicity of MWCNTs and further elucidation of the related toxicological mechanism.We employed an in vivo Caenorhabditis elegans assay system to perform SOLiD sequencing analysis to identify the possible microRNA (miRNA) targets of multi-walled carbon nanotubes (MWCNTs). Bioinformatics analysis on targeted genes for the identified dysregulated miRNAs in MWCNT exposed nematodes demonstrates their involvement in many aspects of biological processes. We used loss-of-function mutants for the identified dysregulated miRNAs to perform toxicity assessment by evaluating functions of primary and secondary targeted organs, and found the miRNA mutants with susceptible or resistant property towards MWCNT toxicity. Both the physiological state of the intestine and defecation behavior were involved in the control of the susceptible or resistant property occurrence for specific miRNA mutants towards MWCNT toxicity. This work provides the molecular basis at the miRNA level for future chemical design to reduce the nanotoxicity of MWCNTs and further elucidation of the

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

    Science.gov (United States)

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

    2010-01-01

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

  6. Single-walled carbon nanotubes disturbed the immune and metabolic regulation function 13-weeks after a single intratracheal instillation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun-Jung, E-mail: pejtoxic@hanmail.net [Myunggok Eye Research Institute, Konyang University, Daejeon 302-718 (Korea, Republic of); Hong, Young-Shick [Division of Food and Nutrition, Chonnam National University, Yongbong-Ro, Buk-Gu, Gwangju 500-757 (Korea, Republic of); Lee, Byoung-Seok [Toxicologic Pathology Center, Korea Institute of Toxicology, Daejeon (Korea, Republic of); Yoon, Cheolho [Seoul Center, Korea Basic Science Institute, Seoul 126-16 (Korea, Republic of); Jeong, Uiseok; Kim, Younghun [Department of Chemical Engineering, Kwangwoon University, Seoul 139-701 (Korea, Republic of)

    2016-07-15

    Due to their unique physicochemical properties, the potential health effects of single-walled carbon nanotubes (SWCNTs) have attracted continuous attention together with their extensive application. In this study, we aimed to identify local and systemic health effects following pulmonary persistence of SWCNTs. As expected, SWCNTs remained in the lung for 13 weeks after a single intratracheal instillation (50, 100, and 200 μg/kg). In the lung, the total number of cells and the percentages of lymphocytes and neutrophils significantly increased at 200 μg/kg compared to the control, and the Th1-polarized immune response was induced accompanying enhanced expression of tissue damage-related genes and increased release of chemokines. Additionally, SWCNTs enhanced the expression of antigen presentation-related proteins on the surface of antigen-presenting cells, however, maturation of dendritic cells was inhibited by their persistence. As compared to the control, a significant increase in the percentage of neutrophils and a remarkable decrease of BUN and potassium level were observed in the blood of mice treated with the highest dose. This was accompanied by the down-regulation of the expression of antigen presentation-related proteins on splenocytes. Moreover, protein and glucose metabolism were disturbed with an up-regulation of fatty acid β-oxidation. Taken together, we conclude that SWCNTs may induce adverse health effects by disturbing immune and metabolic regulation functions in the body. Therefore, careful application of SWCNTs is necessary for the enforcement of safety in nano-industries. - Highlights: • We evaluated local and systemic health effects following persistence of SWCNTs. • SWCNTs remained in the lung for 13 weeks after a single intratracheal instillation. • Th1-polarized immune response was induced in the lung. • The expression of antigen presentation-related proteins was altered. • Immune and metabolic regulation function were disturbed.

  7. Secondary school pupils' food choices around schools in a London borough: Fast food and walls of crisps.

    Science.gov (United States)

    Caraher, M; Lloyd, S; Mansfield, M; Alp, C; Brewster, Z; Gresham, J

    2016-08-01

    The objective was to observe and document food behaviours of secondary school pupils from schools in a London borough. The research design combined a number of methods which included geographic information system (GIS) mapping of food outlets around three schools, systemised observations of food purchasing in those outlets before, during and after school, and focus groups conducted with pupils of those schools to gather their views in respect to those food choices. Results are summarised under the five 'A's of Access, Availability, Affordability and Acceptability & Attitudes: Access in that there were concentrations of food outlets around the schools. The majority of pupil food purchases were from newsagents, small local shops and supermarkets of chocolate, crisps (potato chips), fizzy drinks and energy drinks. Availability of fast food and unhealthy options were a feature of the streets surrounding the schools, with 200 m the optimal distance pupils were prepared to walk from and back to school at lunchtime. Affordability was ensured by the use of a consumer mentality and pupils sought out value for money offers; group purchasing of 'two for one' type offers encouraged this trend. Pupils reported healthy items on sale in school as expensive, and also that food was often sold in smaller portion sizes than that available from external food outlets. Acceptability and Attitudes, in that school food was not seen as 'cool', queuing for school food was not acceptable but queuing for food from takeaways was not viewed negatively; for younger pupils energy drinks were 'cool'. In conclusion, pupils recognised that school food was healthier but provided several reasons for not eating in school related to the five 'A's above. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Perspectives on Teaching and Regulation of Learning: A Comparison of Secondary and University Teachers

    Science.gov (United States)

    Oolbekkink-Marchand, H. W.; Van Driel, J. H.; Verloop, N.

    2014-01-01

    Many factors play a role in the successful transition of students from secondary to university education: one of them is the (university) teacher. In this study the similarities and differences in the perspectives on teaching and learning of secondary and university teachers were investigated. A survey was performed among 675 teachers. Three…

  9. Down-regulation of ABCG2, a urate exporter, by parathyroid hormone enhances urate accumulation in secondary hyperparathyroidism.

    Science.gov (United States)

    Sugimoto, Ryusei; Watanabe, Hiroshi; Ikegami, Komei; Enoki, Yuki; Imafuku, Tadashi; Sakaguchi, Yoshiaki; Murata, Michiya; Nishida, Kento; Miyamura, Shigeyuki; Ishima, Yu; Tanaka, Motoko; Matsushita, Kazutaka; Komaba, Hirotaka; Fukagawa, Masafumi; Otagiri, Masaki; Maruyama, Toru

    2017-03-01

    Hyperuricemia occurs with increasing frequency among patients with hyperparathyroidism. However, the molecular mechanism by which the serum parathyroid hormone (PTH) affects serum urate levels remains unknown. This was studied in uremic rats with secondary hyperparathyroidism where serum urate levels were found to be increased and urate excretion in the intestine and kidney decreased, presumably due to down-regulation of the expression of the urate exporter ABCG2 in intestinal and renal epithelial membranes. These effects were prevented by administration of the calcimimetic cinacalcet, a PTH suppressor, suggesting that PTH may down-regulate ABCG2 expression. This was directly tested in intestinal Caco-2 cells where the expression of ABCG2 on the plasma membrane was down-regulated by PTH (1-34) while its mRNA level remained unchanged. Interestingly, an inactive PTH derivative (13-34) had no effect, suggesting that a posttranscriptional regulatory system acts through the PTH receptor to regulate ABCG2 plasma membrane expression. As found in an animal study, additional clinical investigations showed that treatment with cinacalcet resulted in significant reductions in serum urate levels together with decreases in PTH levels in patients with secondary hyperparathyroidism undergoing dialysis. Thus, PTH down-regulates ABCG2 expression on the plasma membrane to suppress intestinal and renal urate excretion, and the effects of PTH can be prevented by cinacalcet treatment. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  10. Calcium-dependent depletion zones in the cortical microtubule array coincide with sites of, but do not regulate, wall ingrowth papillae deposition in epidermal transfer cells.

    Science.gov (United States)

    Zhang, Hui-ming; Talbot, Mark J; McCurdy, David W; Patrick, John W; Offler, Christina E

    2015-09-01

    Trans-differentiation to a transfer-cell morphology is characterized by the localized deposition of wall ingrowth papillae that protrude into the cytosol. Whether the cortical microtubule array directs wall ingrowth papillae formation was investigated using a Vicia faba cotyledon culture system in which their adaxial epidermal cells were spontaneously induced to trans-differentiate to transfer cells. During deposition of wall ingrowth papillae, the aligned cortical microtubule arrays in precursor epidermal cells were reorganized into a randomized array characterized by circular depletion zones. Concurrence of the temporal appearance, spatial pattern, and size of depletion zones and wall ingrowth papillae was consistent with each papilla occupying a depletion zone. Surprisingly, microtubules appeared not to regulate construction of wall ingrowth papillae, as neither depolymerization nor stabilization of cortical microtubules changed their deposition pattern or morphology. Moreover, the size and spatial pattern of depletion zones was unaltered when the formation of wall ingrowth papillae was blocked by inhibiting cellulose biosynthesis. In contrast, the depletion zones were absent when the cytosolic calcium plumes, responsible for directing wall ingrowth papillae formation, were blocked or dissipated. Thus, we conclude that the depletion zones within the cortical microtubule array result from localized depolymerization of microtubules initiated by elevated cytosolic Ca(2+) levels at loci where wall ingrowth papillae are deposited. The physiological significance of the depletion zones as a mechanism to accommodate the construction of wall ingrowth papillae without compromising maintenance of the plasma membrane-microtubule inter-relationship is discussed. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. A New Secondary Control Approach for Voltage Regulation in DC Microgrids

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Davari, Pooya

    2016-01-01

    feeders with much voltage drop on the line resistances, the conventional methods may not guarantee the voltage regulation on the load busses. Therefore, in addition to compensate the voltage drop of the primary controller, it is necessary to regulate the voltage of critical loads. In this paper, a new...

  12. Evaluation of the Changes in the Regulation of Secondary Education Institutions According to Teachers' Viewpoints (Turkey)

    Science.gov (United States)

    Coskun, Mucahit; Sozen, Erol

    2017-01-01

    The purpose of this study is to evaluate teachers' viewpoints about the changes made in the regulation of passing lesson at schools, which became active in 2013 to 2014 academic year. The pass grade applied depends on this regulation, common exams, shortening of the absenteeism durations, and assigning students with performance tasks according to…

  13. The Mkk2 MAPKK Regulates Cell Wall Biogenesis in Cooperation with the Cek1-Pathway in Candida albicans

    NARCIS (Netherlands)

    Román, Elvira; Alonso-Monge, Rebeca; Miranda Bedate, A.; Pla, Jesús

    2015-01-01

    The cell wall integrity pathway (CWI) plays an important role in the biogenesis of the cell wall in Candida albicans and other fungi. In the present work, the C. albicans MKK2 gene that encodes the putative MAPKK of this pathway was deleted in different backgrounds and the phenotypes of the

  14. Genomics-guided discovery of secondary metabolites and their regulation in Pseudomonas protegens Pf-5

    Science.gov (United States)

    Pseudomonas protegens strain Pf-5 is a well-characterized rhizosphere bacterium known for its production of a diverse spectrum of secondary metabolites and its capacity to suppress plant diseases caused by soilborne fungal, bacterial and oomycete pathogens. Metabolites produced by Pf-5 include 2,4-...

  15. Transcript Profiling Identifies NAC-Domain Genes Involved in Regulating Wall Ingrowth Deposition in Phloem Parenchyma Transfer Cells of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yuzhou Wu

    2018-03-01

    Full Text Available Transfer cells (TCs play important roles in facilitating enhanced rates of nutrient transport at key apoplasmic/symplasmic junctions along the nutrient acquisition and transport pathways in plants. TCs achieve this capacity by developing elaborate wall ingrowth networks which serve to increase plasma membrane surface area thus increasing the cell's surface area-to-volume ratio to achieve increased flux of nutrients across the plasma membrane. Phloem parenchyma (PP cells of Arabidopsis leaf veins trans-differentiate to become PP TCs which likely function in a two-step phloem loading mechanism by facilitating unloading of photoassimilates into the apoplasm for subsequent energy-dependent uptake into the sieve element/companion cell (SE/CC complex. We are using PP TCs in Arabidopsis as a genetic model to identify transcription factors involved in coordinating deposition of the wall ingrowth network. Confocal imaging of pseudo-Schiff propidium iodide-stained tissue revealed different profiles of temporal development of wall ingrowth deposition across maturing cotyledons and juvenile leaves, and a basipetal gradient of deposition across mature adult leaves. RNA-Seq analysis was undertaken to identify differentially expressed genes common to these three different profiles of wall ingrowth deposition. This analysis identified 68 transcription factors up-regulated two-fold or more in at least two of the three experimental comparisons, with six of these transcription factors belonging to Clade III of the NAC-domain family. Phenotypic analysis of these NAC genes using insertional mutants revealed significant reductions in levels of wall ingrowth deposition, particularly in a double mutant of NAC056 and NAC018, as well as compromised sucrose-dependent root growth, indicating impaired capacity for phloem loading. Collectively, these results support the proposition that Clade III members of the NAC-domain family in Arabidopsis play important roles in

  16. Combinatorial function of velvet and AreA in transcriptional regulation of nitrate utilization and secondary metabolism.

    Science.gov (United States)

    López-Berges, Manuel S; Schäfer, Katja; Hera, Concepción; Di Pietro, Antonio

    2014-01-01

    Velvet is a conserved protein complex that functions as a regulator of fungal development and secondary metabolism. In the soil-inhabiting pathogen Fusarium oxysporum, velvet governs mycotoxin production and virulence on plant and mammalian hosts. Here we report a previously unrecognized role of the velvet complex in regulation of nitrate metabolism. F. oxysporum mutants lacking VeA or LaeA, two key components of the complex, were impaired in growth on the non-preferred nitrogen sources nitrate and nitrite. Both velvet and the general nitrogen response GATA factor AreA were required for transcriptional activation of nitrate (nit1) and nitrite (nii1) reductase genes under de-repressing conditions, as well as for the nitrate-triggered increase in chromatin accessibility at the nit1 locus. AreA also contributed to chromatin accessibility and expression of two velvet-regulated gene clusters, encoding biosynthesis of the mycotoxin beauvericin and of the siderophore ferricrocin. Thus, velvet and AreA coordinately orchestrate primary and secondary metabolism as well as virulence functions in F. oxysporum. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. The MAP kinase-activated protein kinase Rck2p regulates cellular responses to cell wall stresses, filamentation and virulence in the human fungal pathogen Candida albicans.

    Science.gov (United States)

    Li, Xichuan; Du, Wei; Zhao, Jingwen; Zhang, Lilin; Zhu, Zhiyan; Jiang, Linghuo

    2010-06-01

    Rck2p is the Hog1p-MAP kinase-activated protein kinase required for the attenuation of protein synthesis in response to an osmotic challenge in Saccharomyces cerevisiae. Rck2p also regulates rapamycin sensitivity in both S. cerevisiae and Candida albicans. In this study, we demonstrate that the deletion of CaRCK2 renders C. albicans cells sensitive to, and CaRck2p translocates from the cytosol to the nucleus in response to, cell wall stresses caused by Congo red, Calcoflor White, elevated heat and zymolyase. However, the kinase activity of CaRck2p is not required for the cellular response to these cell wall stresses. Furthermore, transcripts of cell wall protein-encoding genes CaBGL2, CaHWP1 and CaXOG1 are reduced in C. albicans cells lacking CaRCK2. The deletion of CaRCK2 also reduces the in vitro filamentation of C. albicans and its virulence in a mouse model of systemic candidasis. The kinase activity of CaRck2p is required for the virulence, but not for the in vitro filamentation, in C. albicans. Therefore, Rck2p regulates cellular responses to cell wall stresses, filamentation and virulence in the human fungal pathogen C. albicans.

  18. Secondary Plant Products Causing Photosensitization in Grazing Herbivores: Their Structure, Activity and Regulation

    Directory of Open Access Journals (Sweden)

    Jane C. Quinn

    2014-01-01

    Full Text Available Photosensitivity in animals is defined as a severe dermatitis that results from a heightened reactivity of skin cells and associated dermal tissues upon their exposure to sunlight, following ingestion or contact with UV reactive secondary plant products. Photosensitivity occurs in animal cells as a reaction that is mediated by a light absorbing molecule, specifically in this case a plant-produced metabolite that is heterocyclic or polyphenolic. In sensitive animals, this reaction is most severe in non-pigmented skin which has the least protection from UV or visible light exposure. Photosensitization in a biological system such as the epidermis is an oxidative or other chemical change in a molecule in response to light-induced excitation of endogenous or exogenously-delivered molecules within the tissue. Photo-oxidation can also occur in the plant itself, resulting in the generation of reactive oxygen species, free radical damage and eventual DNA degradation. Similar cellular changes occur in affected herbivores and are associated with an accumulation of photodynamic molecules in the affected dermal tissues or circulatory system of the herbivore. Recent advances in our ability to identify and detect secondary products at trace levels in the plant and surrounding environment, or in organisms that ingest plants, have provided additional evidence for the role of secondary metabolites in photosensitization of grazing herbivores. This review outlines the role of unique secondary products produced by higher plants in the animal photosensitization process, describes their chemistry and localization in the plant as well as impacts of the environment upon their production, discusses their direct and indirect effects on associated animal systems and presents several examples of well-characterized plant photosensitization in animal systems.

  19. Shear-stress and wall-stress regulation of vascular remodeling after balloon angioplasty: effect of matrix metalloproteinase inhibition

    NARCIS (Netherlands)

    C.J. Slager (Cornelis); J. Kloet (Jeroen); J.A.F. Oomen; J.C.H. Schuurbiers (Johan); B.J. de Smet; M.J. Post (Mark); D.P.V. de Kleijn (Dominique); G. Pasterkamp (Gerard); R. Krams (Rob); C. Borst (Cornelius); J.J. Wentzel (Jolanda); I. Andhyiswara (Ivan)

    2001-01-01

    textabstractBACKGROUND: Constrictive vascular remodeling (VR) is the most significant component of restenosis after balloon angioplasty (PTA). Whereas in physiological conditions VR is associated with normalization of shear stress (SS) and wall stress (WS), after PTA

  20. Hsp90 orchestrates transcriptional regulation by Hsf1 and cell wall remodelling by MAPK signalling during thermal adaptation in a pathogenic yeast.

    Directory of Open Access Journals (Sweden)

    Michelle D Leach

    2012-12-01

    Full Text Available Thermal adaptation is essential in all organisms. In yeasts, the heat shock response is commanded by the heat shock transcription factor Hsf1. Here we have integrated unbiased genetic screens with directed molecular dissection to demonstrate that multiple signalling cascades contribute to thermal adaptation in the pathogenic yeast Candida albicans. We show that the molecular chaperone heat shock protein 90 (Hsp90 interacts with and down-regulates Hsf1 thereby modulating short term thermal adaptation. In the longer term, thermal adaptation depends on key MAP kinase signalling pathways that are associated with cell wall remodelling: the Hog1, Mkc1 and Cek1 pathways. We demonstrate that these pathways are differentially activated and display cross talk during heat shock. As a result ambient temperature significantly affects the resistance of C. albicans cells to cell wall stresses (Calcofluor White and Congo Red, but not osmotic stress (NaCl. We also show that the inactivation of MAP kinase signalling disrupts this cross talk between thermal and cell wall adaptation. Critically, Hsp90 coordinates this cross talk. Genetic and pharmacological inhibition of Hsp90 disrupts the Hsf1-Hsp90 regulatory circuit thereby disturbing HSP gene regulation and reducing the resistance of C. albicans to proteotoxic stresses. Hsp90 depletion also affects cell wall biogenesis by impairing the activation of its client proteins Mkc1 and Hog1, as well as Cek1, which we implicate as a new Hsp90 client in this study. Therefore Hsp90 modulates the short term Hsf1-mediated activation of the classic heat shock response, coordinating this response with long term thermal adaptation via Mkc1- Hog1- and Cek1-mediated cell wall remodelling.

  1. Tamoxifen up-regulates catalase production, inhibits vessel wall neutrophil infiltration, and attenuates development of experimental abdominal aortic aneurysms.

    Science.gov (United States)

    Grigoryants, Vladimir; Hannawa, Kevin K; Pearce, Charles G; Sinha, Indranil; Roelofs, Karen J; Ailawadi, Gorav; Deatrick, Kristopher B; Woodrum, Derek T; Cho, Brenda S; Henke, Peter K; Stanley, James C; Eagleton, Matthew J; Upchurch, Gilbert R

    2005-01-01

    controls on day 7 (P = .05). Administration of the direct catalase inhibitor AT to tamoxifen-treated rats partially reversed the aneurysm inhibitory effect of tamoxifen by nearly 30% (P = .02). In contrast, catalase administration inhibited AAA formation by 44% (P = .002). The selective estrogen receptor modulator tamoxifen inhibits the development of AAAs in male rats in association with an up-regulation of catalase and inhibition of aortic wall neutrophil infiltration.

  2. The Sur7 protein regulates plasma membrane organization and prevents intracellular cell wall growth in Candida albicans.

    Science.gov (United States)

    Alvarez, Francisco J; Douglas, Lois M; Rosebrock, Adam; Konopka, James B

    2008-12-01

    The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Delta mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Delta mutant are similar to the effects of inhibiting beta-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains.

  3. Tracking Walls, Take-It-Or-Leave-It Choices, the GDPR, and the ePrivacy Regulation

    NARCIS (Netherlands)

    Zuiderveen Borgesius, F.J.; Kruikemeier, S.; Boerman, S.C.; Helberger, N.

    2017-01-01

    On the internet, we encounter take-it-or-leave-it choices regarding our privacy on a daily basis. In Europe, online tracking for targeted advertising generally requires the internet users’ consent to be lawful. Some websites use a tracking wall, a barrier that visitors can only pass if they consent

  4. The Sur7 Protein Regulates Plasma Membrane Organization and Prevents Intracellular Cell Wall Growth in Candida albicans

    Science.gov (United States)

    Alvarez, Francisco J.; Douglas, Lois M.; Rosebrock, Adam

    2008-01-01

    The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Δ mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Δ mutant are similar to the effects of inhibiting β-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains. PMID:18799621

  5. Profiling of secondary metabolite gene clusters regulated by LaeA in Aspergillus niger FGSC A1279 based on genome sequencing and transcriptome analysis.

    Science.gov (United States)

    Wang, Bin; Lv, Yangyong; Li, Xuejie; Lin, Yiying; Deng, Hai; Pan, Li

    The global regulator LaeA controls the production of many fungal secondary metabolites, possibly via chromatin remodeling. Here we aimed to survey the secondary metabolite profile regulated by LaeA in Aspergillus niger FGSC A1279 by genome sequencing and comparative transcriptomics between the laeA deletion (ΔlaeA) and overexpressing (OE-laeA) mutants. Genome sequencing revealed four putative polyketide synthase genes specific to FGSC A1279, suggesting that the corresponding polyketide compounds might be unique to FGSC A1279. RNA-seq data revealed 281 putative secondary metabolite genes upregulated in the OE-laeA mutants, including 22 secondary metabolite backbone genes. LC-MS chemical profiling illustrated that many secondary metabolites were produced in OE-laeA mutants compared to wild type and ΔlaeA mutants, providing potential resources for drug discovery. KEGG analysis annotated 16 secondary metabolite clusters putatively linked to metabolic pathways. Furthermore, 34 of 61 Zn 2 Cys 6 transcription factors located in secondary metabolite clusters were differentially expressed between ΔlaeA and OE-laeA mutants. Three secondary metabolite clusters (cluster 18, 30 and 33) containing Zn 2 Cys 6 transcription factors that were upregulated in OE-laeA mutants were putatively linked to KEGG pathways, suggesting that Zn 2 Cys 6 transcription factors might play an important role in synthesizing secondary metabolites regulated by LaeA. Taken together, LaeA dramatically influences the secondary metabolite profile in FGSC A1279. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. Hemin and bile pigments are the secondary structure regulators of intrinsically disordered antimicrobial peptides.

    Science.gov (United States)

    Zsila, Ferenc; Juhász, Tünde; Bősze, Szilvia; Horváti, Kata; Beke-Somfai, Tamás

    2018-02-01

    The interaction of protoporphyrin compounds of human origin with the major bee venom component melittin (26 a.a., Z +6) and its hybrid derivative (CM15, 15 a.a., Z +6) were studied by a combination of various spectroscopic methods. Throughout a two-state, concentration-dependent process, hemin and its metabolites (biliverdin, bilirubin, bilirubin ditaurate) increase the parallel β-sheet content of the natively unfolded melittin, suggesting the oligomerization of the peptide chains. In contrast, α-helix promoting effect was observed with the also disordered but more cationic CM15. According to fluorescence quenching experiments, the sole Trp residue of melittin is the key player during the binding, in the vicinity of which the first pigment molecule is accommodated presumably making indole-porphyrin π-π stacking interaction. As circular dichroism titration data suggest, cooperative association of additional ligands subsequently occurs, resulting in multimeric complexes with an apparent dissociation constant ranged from 20 to 65 μM. Spectroscopic measurements conducted with the bilirubin catabolite urobilin and stercobilin refer to the requirement of intact dipyrrinone moieties for inducing secondary structure transformations. The binding topography of porphyrin rings on a model parallel β-sheet motif was evaluated by absorption spectroscopy and computational modeling showing a slipped-cofacial binding mode responsible for the red shift and hypochromism of the Soret band. Our results may aid to recognize porphyrin-responsive binding motifs of biologically relevant, intrinsically disordered peptides and proteins, where transient conformations play a vital role in their functions. © 2017 Wiley Periodicals, Inc.

  7. The cross-pathway control system regulates production of the secondary metabolite toxin, sirodesmin PL, in the ascomycete, Leptosphaeria maculans

    Directory of Open Access Journals (Sweden)

    Fox Ellen M

    2011-07-01

    Full Text Available Abstract Background Sirodesmin PL is a secondary metabolite toxin made by the ascomycetous plant pathogen, Leptosphaeria maculans. The sirodesmin biosynthetic genes are clustered in the genome. The key genes are a non-ribosomal peptide synthetase, sirP, and a pathway-specific transcription factor, sirZ. Little is known about regulation of sirodesmin production. Results Genes involved in regulation of sirodesmin PL in L. maculans have been identified. Two hundred random insertional T-DNA mutants were screened with an antibacterial assay for ones producing low levels of sirodesmin PL. Three such mutants were isolated and each transcribed sirZ at very low levels. One of the affected genes had high sequence similarity to Aspergillus fumigatus cpcA, which regulates the cross-pathway control system in response to amino acid availability. This gene was silenced in L. maculans and the resultant mutant characterised. When amino acid starvation was artificially-induced by addition of 3-aminotriazole for 5 h, transcript levels of sirP and sirZ did not change in the wild type. In contrast, levels of sirP and sirZ transcripts increased in the silenced cpcA mutant. After prolonged amino acid starvation the silenced cpcA mutant produced much higher amounts of sirodesmin PL than the wild type. Conclusions Production of sirodesmin PL in L. maculans is regulated by the cross pathway control gene, cpcA, either directly or indirectly via the pathway-specific transcription factor, sirZ.

  8. Immunosenescence Is Associated With Altered Gene Expression And Epigenetic Regulation In Primary And Secondary Immune Organs

    Directory of Open Access Journals (Sweden)

    Corinne eSidler

    2013-10-01

    Full Text Available Deterioration of the immune system (immunosenescence with age is associated with an increased susceptibility to infection, autoimmune disease and cancer, and reduced responsiveness to vaccination. Immunosenescence entails a reduced supply of naïve T cells from the thymus and increased specialization of peripheral T cell clones. Both thymic involution and peripheral T cell homeostasis are thought to involve cellular senescence. In order to analyze this at the molecular level, we studied gene expression profiles, epigenetic status and genome stability in the thymus and spleen of 1-month, 4-month and 18-month-old Long Evans rats. In the thymus, altered gene expression, DNA and histone hypomethylation, increased genome instability and apoptosis were observed in 18-month-old animals compared to 1- and 4-month-old animals. In the spleen, alterations in gene expression and epigenetic regulation occurred already by the age of 4 months compared to 1 month and persisted in 18-month-old compared to 1-month-old rats. In both organs, these changes were accompanied by the altered composition of resident T cell populations. Our study suggests that both senescence and apoptosis may be involved in altered organ function.

  9. Ultrasound enhances calcium absorption of jujube fruit by regulating the cellular calcium distribution and metabolism of cell wall polysaccharides.

    Science.gov (United States)

    Zhi, Huanhuan; Liu, Qiqi; Xu, Juan; Dong, Yu; Liu, Mengpei; Zong, Wei

    2017-12-01

    Ultrasound has been applied in fruit pre-washing processes. However, it is not sufficient to protect fruit from pathogenic infection throughout the entire storage period, and sometimes ultrasound causes tissue damage. The goal of this study was to investigate the effects of calcium chloride (CaCl 2 , 10 g L -1 ) and ultrasound (350 W at 40 kHz), separately and in combination, on jujube fruit quality, antioxidant status, tissue Ca 2+ content and distribution along with cell wall metabolism at 20 °C for 6 days. All three treatments significantly maintained fruit firmness and peel color, reduced respiration rate, decay incidence, superoxide anion, hydrogen peroxide and malondialdehyde and preserved higher enzymatic (superoxide dismutase, catalase and peroxidase) and non-enzymatic (ascorbic acid and glutathione) antioxidants compared with the control. Moreover, the combined treatment was more effective in increasing tissue Ca 2+ content and distribution, inhibiting the generation of water-soluble and CDTA-soluble pectin fractions, delaying the solubilization of Na 2 CO 3 -soluble pectin and having lower activities of cell wall-modifying enzymes (polygalacturonase and pectate lyase) during storage. These results demonstrated that the combination of CaCl 2 and ultrasound has potential commercial application to extend the shelf life of jujube fruit by facilitating Ca 2+ absorption and stabilizing the cell wall structure. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Treatment of necrotic infection on the anterior chest wall secondary to mastectomy and postoperative radiotherapy by the application of omentum and mesh skin grafting. Report of a case

    International Nuclear Information System (INIS)

    Sato, Masaaki; Tanaka, Fumihiro; Wada, Hiromi

    2002-01-01

    We report herein the case of a patient who initially underwent right radical mastectomy for breast carcinoma in 1988, followed by left breast-conserving surgery in 1997. On both occasions she was given postoperative radiation therapy of 50 Gy. Repeated dressings and the administration of antibiotics failed to heal ulcerative infected lesions that had formed on the anterior chest wall in early 1998. In 1999, the sternum and surrounding tissue were debrided and the anterior chest wall was reconstructed by omentum transposition and mesh skin grafting. The patient is currently well and alive without any evidence of recurrence of either infection or breast cancer. (author)

  11. Crystal Structure of the CTP1L Endolysin Reveals How Its Activity Is Regulated by a Secondary Translation Product.

    Science.gov (United States)

    Dunne, Matthew; Leicht, Stefan; Krichel, Boris; Mertens, Haydyn D T; Thompson, Andrew; Krijgsveld, Jeroen; Svergun, Dmitri I; Gómez-Torres, Natalia; Garde, Sonia; Uetrecht, Charlotte; Narbad, Arjan; Mayer, Melinda J; Meijers, Rob

    2016-03-04

    Bacteriophages produce endolysins, which lyse the bacterial host cell to release newly produced virions. The timing of lysis is regulated and is thought to involve the activation of a molecular switch. We present a crystal structure of the activated endolysin CTP1L that targets Clostridium tyrobutyricum, consisting of a complex between the full-length protein and an N-terminally truncated C-terminal cell wall binding domain (CBD). The truncated CBD is produced through an internal translation start site within the endolysin gene. Mutants affecting the internal translation site change the oligomeric state of the endolysin and reduce lytic activity. The activity can be modulated by reconstitution of the full-length endolysin-CBD complex with free CBD. The same oligomerization mechanism applies to the CD27L endolysin that targets Clostridium difficile and the CS74L endolysin that targets Clostridium sporogenes. When the CTP1L endolysin gene is introduced into the commensal bacterium Lactococcus lactis, the truncated CBD is also produced, showing that the alternative start codon can be used in other bacterial species. The identification of a translational switch affecting oligomerization presented here has implications for the design of effective endolysins for the treatment of bacterial infections. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. 78 FR 54758 - Modification of Treasury Regulations Pursuant to Section 939A of the Dodd-Frank Wall Street...

    Science.gov (United States)

    2013-09-06

    ... provisions under the Internal Revenue Code (Code) are affected. These regulations amend the Income Tax... Chief Counsel (Income Tax and Accounting), the Office of the Associate Chief Counsel (International) and... Excise taxes, Reporting and recordkeeping requirements. Adoption of Amendments to the Regulations...

  13. Temporal Regulation of the Bacillus subtilis Acetylome and Evidence for a Role of MreB Acetylation in Cell Wall Growth.

    Science.gov (United States)

    Carabetta, Valerie J; Greco, Todd M; Tanner, Andrew W; Cristea, Ileana M; Dubnau, David

    2016-05-01

    N ε -Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the Bacillus subtilis acetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter. The past decade highlighted N ε -lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases in B. subtilis . To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized MreB, the cell

  14. Ethylene regulates Apple (Malus x domestica) fruit softening through a dose x time-dependent mechanism and through differential sensitivities and dependencies of cell wall-modifying genes.

    Science.gov (United States)

    Ireland, Hilary S; Gunaseelan, Kularajathevan; Muddumage, Ratnasiri; Tacken, Emma J; Putterill, Jo; Johnston, Jason W; Schaffer, Robert J

    2014-05-01

    In fleshy fruit species that have a strong requirement for ethylene to ripen, ethylene is synthesized autocatalytically, producing increasing concentrations as the fruits ripen. Apple fruit with the ACC OXIDASE 1 (ACO1) gene suppressed cannot produce ethylene autocatalytically at ripening. Using these apple lines, an ethylene sensitivity dependency model was previously proposed, with traits such as softening showing a high dependency for ethylene as well as low sensitivity. In this study, it is shown that the molecular control of fruit softening is a complex process, with different cell wall-related genes being independently regulated and exhibiting differential sensitivities to and dependencies on ethylene at the transcriptional level. This regulation is controlled through a dose × time mechanism, which results in a temporal transcriptional response that would allow for progressive cell wall disassembly and thus softening. This research builds on the sensitivity dependency model and shows that ethylene-dependent traits can progress over time to the same degree with lower levels of ethylene. This suggests that a developmental clock measuring cumulative ethylene controls the fruit ripening process.

  15. Grafted c-kit+/SSEA1- eye-wall progenitor cells delay retinal degeneration in mice by regulating neural plasticity and forming new graft-to-host synapses.

    Science.gov (United States)

    Chen, Xi; Chen, Zehua; Li, Zhengya; Zhao, Chen; Zeng, Yuxiao; Zou, Ting; Fu, Caiyun; Liu, Xiaoli; Xu, Haiwei; Yin, Zheng Qin

    2016-12-30

    Despite diverse pathogenesis, the common pathological change observed in age-related macular degeneration and in most hereditary retinal degeneration (RD) diseases is photoreceptor loss. Photoreceptor replacement by cell transplantation may be a feasible treatment for RD. The major obstacles to clinical translation of stem cell-based cell therapy in RD remain the difficulty of obtaining sufficient quantities of appropriate and safe donor cells and the poor integration of grafted stem cell-derived photoreceptors into the remaining retinal circuitry. Eye-wall c-kit + /stage-specific embryonic antigen 1 (SSEA1) - cells were isolated via fluorescence-activated cell sorting, and their self-renewal and differentiation potential were detected by immunochemistry and flow cytometry in vitro. After labeling with quantum nanocrystal dots and transplantation into the subretinal space of rd1 RD mice, differentiation and synapse formation by daughter cells of the eye-wall c-kit + /SSEA1 - cells were evaluated by immunochemistry and western blotting. Morphological changes of the inner retina of rd1 mice after cell transplantation were demonstrated by immunochemistry. Retinal function of rd1 mice that received cell grafts was tested via flash electroretinograms and the light/dark transition test. Eye-wall c-kit + /SSEA1 - cells were self-renewing and clonogenic, and they retained their proliferative potential through more than 20 passages. Additionally, eye-wall c-kit + /SSEA1 - cells were capable of differentiating into multiple retinal cell types including photoreceptors, bipolar cells, horizontal cells, amacrine cells, Müller cells, and retinal pigment epithelium cells and of transdifferentiating into smooth muscle cells and endothelial cells in vitro. The levels of synaptophysin and postsynaptic density-95 in the retinas of eye-wall c-kit + /SSEA1 - cell-transplanted rd1 mice were significantly increased at 4 weeks post transplantation. The c-kit + /SSEA1 - cells were

  16. Physiological regulation of extracellular matrix collagen and elastin in the arterial wall of rats by noradrenergic tone and angiotensin II.

    Science.gov (United States)

    Dab, Houcine; Kacem, Kamel; Hachani, Rafik; Dhaouadi, Nadra; Hodroj, Wassim; Sakly, Mohsen; Randon, Jacques; Bricca, Giampiero

    2012-03-01

    The interactions between the effects of the sympathetic nervous system (SNS) and angiotensin II (ANG II) on vascular extracellular matrix (ECM) synthesis were determined in rats. The mRNA and protein content of collagen I, collagen III and elastin in the abdominal aorta (AA) and femoral artery (FA) was investigated in Wistar-Kyoto rats treated for 5 weeks with guanethidine, a sympathoplegic, losartan, an ANG II AT1 receptor (AT1R) blocker, or both. The effects of noradrenaline (NE) and ANG II on collagen III and elastin mRNA, and the receptor involved, were tested in cultured vascular smooth muscle cells (VSMCs) in vitro. Guanethidine increased collagen types I and III and decreased elastin, while losartan had an opposite effect, although without effect on collagen III. The combination of treatments abrogated changes induced by simple treatment with collagen I and elastin, but increased collagen III mRNA in AA and not in FA. NE stimulated collagen III mRNA via β receptors and elastin via α1 and α2 receptors. ANG II stimulated collagen III but inhibited elastin mRNA via AT1R. Overall, SNS and ANG II exert opposite and antagonistic effects on major components of ECM in the vascular wall. This may be of relevance for the choice of a therapeutic strategy in vascular diseases.

  17. Experience in connecting the power generating units of thermal power plants to automatic secondary frequency regulation within the united power system of Russia

    International Nuclear Information System (INIS)

    Zhukov, A. V.; Komarov, A. N.; Safronov, A. N.; Barsukov, I. V.

    2009-01-01

    The principles of central control of the power generating units of thermal power plants by automatic secondary frequency and active power overcurrent regulation systems, and the algorithms for interactions between automatic power control systems for the power production units in thermal power plants and centralized systems for automatic frequency and power regulation, are discussed. The order of switching the power generating units of thermal power plants over to control by a centralized system for automatic frequency and power regulation and by the Central Coordinating System for automatic frequency and power regulation is presented. The results of full-scale system tests of the control of power generating units of the Kirishskaya, Stavropol, and Perm GRES (State Regional Electric Power Plants) by the Central Coordinating System for automatic frequency and power regulation at the United Power System of Russia on September 23-25, 2008, are reported.

  18. The Root Hair Specific SYP123 Regulates the Localization of Cell Wall Components and Contributes to Rizhobacterial Priming of Induced Systemic Resistance

    Directory of Open Access Journals (Sweden)

    Cecilia Rodriguez-Furlán

    2016-07-01

    Full Text Available Root hairs are important for nutrient and water uptake and are also critically involved the interaction with soil inhabiting microbiota. Root hairs are tubular-shaped outgrowths that emerge from trichoblasts. This polarized elongation is maintained and regulated by a robust mechanism involving the endomembrane secretory and endocytic system. Members of the syntaxin family of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptor in plants (SYP, have been implicated in regulation of the fusion of vesicles with the target membranes in both exocytic and endocytic pathways. One member of this family, SYP123, is expressed specifically in the root hairs and accumulated in the growing tip region. This study shows evidence of the SYP123 role in polarized trafficking using knockout insertional mutant plants. We were able to observe defects in the deposition of cell wall proline rich protein PRP3 and cell wall polysaccharides. In a complementary strategy, similar results were obtained using a plant expressing a dominant negative soluble version of SYP123 (SP2 fragment lacking the transmembrane domain. The evidence presented indicates that SYP123 is also regulating PRP3 protein distribution by recycling by endocytosis. We also present evidence that indicates that SYP123 is necessary for the response of roots to plant growth promoting rhizobacterium (PGPR in order to trigger trigger induced systemic response (ISR. Plants with a defective SYP123 function were unable to mount a systemic acquired resistance (SAR in response to bacterial pathogen infection and induced systemic resistance (ISR upon interaction with rhizobacteria. These results indicated that SYP123 was involved in the polarized localization of protein and polysaccharides in growing root hairs and that this activity also contributed to the establishment of effective plant defense responses. Root hairs represent very plastic structures were many biotic and abiotic factors

  19. The Construct Validity of the German Academic Self-regulation Questionnaire (SRQ-A within Primary and Secondary School Children

    Directory of Open Access Journals (Sweden)

    Julia Kröner

    2017-06-01

    Full Text Available The assessment of students' motivation can be a powerful tool in enhancing and understanding students' learning. One valid and often applied self-report measure is the Academic Self-Regulation Questionnaire (SRQ-A which is grounded in the self-determination theory. However, to date, there is still no German equivalent to the English version of this questionnaire. Therefore, the aim of the present study was to adapt and validate the SRQ-A on a representative German student sample, consisting of 672 children (327 girls, ages 8–14 from one primary and two secondary German schools. First, the translation-back-translation method was used to ensure the linguistic equivalence of the German questionnaire. Second, item analysis of the generated scores of the German SRQ-A were conducted. Third, the multidimensional factorial structure of the original measure was tested with confirmatory factor analysis (CFA using maximum likelihood estimation. Last, additional construct validity of the German SRQ-A was tested using correlational analyses with convergent and divergent measures. After conducting CFA, four items were excluded from the original questionnaire, due to loadings lower than 0.40, resulting in 28 items. The German SRQ-A showed good internal consistency for all subscales, with Chronbach's α ranging between 0.75 and 0.88. The simplex-structure of the original measurement could also be confirmed, however, the four-factorial model could not be replicated. The measurement showed good convergent and discriminant validity with other related questionnaires. In summary, the German SRQ-A is a reliable and valid self-report instrument for the assessment of self-determined motivational styles within the school context.

  20. Four Novel Cellulose Synthase (CESA Genes from Birch (Betula platyphylla Suk. Involved in Primary and Secondary Cell Wall Biosynthesis

    Directory of Open Access Journals (Sweden)

    Xuemei Liu

    2012-09-01

    Full Text Available Cellulose synthase (CESA, which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, −4, −7 and −8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula.

  1. A mitogen-activated protein kinase Tmk3 participates in high osmolarity resistance, cell wall integrity maintenance and cellulase production regulation in Trichoderma reesei.

    Directory of Open Access Journals (Sweden)

    Mingyu Wang

    Full Text Available The mitogen-activated protein kinase (MAPK pathways are important signal transduction pathways conserved in essentially all eukaryotes, but haven't been subjected to functional studies in the most important cellulase-producing filamentous fungus Trichoderma reesei. Previous reports suggested the presence of three MAPKs in T. reesei: Tmk1, Tmk2, and Tmk3. By exploring the phenotypic features of T. reesei Δtmk3, we first showed elevated NaCl sensitivity and repressed transcription of genes involved in glycerol/trehalose biosynthesis under higher osmolarity, suggesting Tmk3 participates in high osmolarity resistance via derepression of genes involved in osmotic stabilizer biosynthesis. We also showed significant downregulation of genes encoding chitin synthases and a β-1,3-glucan synthase, decreased chitin content, 'budded' hyphal appearance typical to cell wall defective strains, and increased sensitivity to calcofluor white/Congo red in the tmk3 deficient strain, suggesting Tmk3 is involved in cell wall integrity maintenance in T. reesei. We further observed the decrease of cellulase transcription and production in T. reesei Δtmk3 during submerged cultivation, as well as the presence of MAPK phosphorylation sites on known transcription factors involved in cellulase regulation, suggesting Tmk3 is also involved in the regulation of cellulase production. Finally, the expression of cell wall integrity related genes, the expression of cellulase coding genes, cellulase production and biomass accumulation were compared between T. reesei Δtmk3 grown in solid state media and submerged media, showing a strong restoration effect in solid state media from defects resulted from tmk3 deletion. These results showed novel physiological processes that fungal Hog1-type MAPKs are involved in, and present the first experimental investigation of MAPK signaling pathways in T. reesei. Our observations on the restoration effect during solid state cultivation suggest

  2. A Mitogen-Activated Protein Kinase Tmk3 Participates in High Osmolarity Resistance, Cell Wall Integrity Maintenance and Cellulase Production Regulation in Trichoderma reesei

    Science.gov (United States)

    Wang, Mingyu; Zhao, Qiushuang; Yang, Jinghua; Jiang, Baojie; Wang, Fangzhong; Liu, Kuimei; Fang, Xu

    2013-01-01

    The mitogen-activated protein kinase (MAPK) pathways are important signal transduction pathways conserved in essentially all eukaryotes, but haven't been subjected to functional studies in the most important cellulase-producing filamentous fungus Trichoderma reesei. Previous reports suggested the presence of three MAPKs in T. reesei: Tmk1, Tmk2, and Tmk3. By exploring the phenotypic features of T. reesei Δtmk3, we first showed elevated NaCl sensitivity and repressed transcription of genes involved in glycerol/trehalose biosynthesis under higher osmolarity, suggesting Tmk3 participates in high osmolarity resistance via derepression of genes involved in osmotic stabilizer biosynthesis. We also showed significant downregulation of genes encoding chitin synthases and a β-1,3-glucan synthase, decreased chitin content, ‘budded’ hyphal appearance typical to cell wall defective strains, and increased sensitivity to calcofluor white/Congo red in the tmk3 deficient strain, suggesting Tmk3 is involved in cell wall integrity maintenance in T. reesei. We further observed the decrease of cellulase transcription and production in T. reesei Δtmk3 during submerged cultivation, as well as the presence of MAPK phosphorylation sites on known transcription factors involved in cellulase regulation, suggesting Tmk3 is also involved in the regulation of cellulase production. Finally, the expression of cell wall integrity related genes, the expression of cellulase coding genes, cellulase production and biomass accumulation were compared between T. reesei Δtmk3 grown in solid state media and submerged media, showing a strong restoration effect in solid state media from defects resulted from tmk3 deletion. These results showed novel physiological processes that fungal Hog1-type MAPKs are involved in, and present the first experimental investigation of MAPK signaling pathways in T. reesei. Our observations on the restoration effect during solid state cultivation suggest that T. reesei

  3. Adaptive responses to cefotaxime treatment in ESBL-producing Escherichia coli and the possible use of significantly regulated pathways as novel secondary targets

    DEFF Research Database (Denmark)

    Møller, Thea S. B.; Rau, Martin Holm; Bonde, Charlotte S

    2016-01-01

    The aim of the study was to determine how ESBL-producing Escherichia coli change the expression of metabolic and biosynthesis genes when adapting to inhibitory concentrations of cefotaxime. Secondly, it was investigated whether significantly regulated pathways constitute putative secondary targets......-fold). Inhibition and/or mutations in other genes that were significantly regulated, belonging to energy synthesis, purine synthesis, proline uptake or potassium uptake, also rendered the resistant bacteria more susceptible to cefotaxime. The results show that ESBL-producing E. coli adapt to treatment...

  4. The ATP-Dependent Protease ClpP Inhibits Biofilm Formation by Regulating Agr and Cell Wall Hydrolase Sle1 in Staphylococcus aureus

    Science.gov (United States)

    Liu, Qian; Wang, Xing; Qin, Juanxiu; Cheng, Sen; Yeo, Won-Sik; He, Lei; Ma, Xiaowei; Liu, Xiaoyun; Li, Min; Bae, Taeok

    2017-01-01

    Biofilm causes hospital-associated infections on indwelling medical devices. In Staphylococcus aureus, Biofilm formation is controlled by intricately coordinated network of regulating systems, of which the ATP-dependent protease ClpP shows an inhibitory effect. Here, we demonstrate that the inhibitory effect of ClpP on biofilm formation is through Agr and the cell wall hydrolase Sle1. Biofilm formed by clpP mutant consists of proteins and extracellular DNA (eDNA). The increase of the protein was, at least in part, due to the reduced protease activity of the mutant, which was caused by the decreased activity of agr. On the other hand, the increase of eDNA was due to increased cell lysis caused by the higher level of Sle1. Indeed, as compared with wild type, the clpP mutant excreted an increased level of eDNA, and showed higher sensitivity to Triton-induced autolysis. The deletion of sle1 in the clpP mutant decreased the biofilm formation, the level of eDNA, and the Triton-induced autolysis to wild-type levels. Despite the increased biofilm formation capability, however, the clpP mutant showed significantly reduced virulence in a murine model of subcutaneous foreign body infection, indicating that the increased biofilm formation capability cannot compensate for the intrinsic functions of ClpP during infection. PMID:28555174

  5. The ATP-Dependent Protease ClpP Inhibits Biofilm Formation by Regulating Agr and Cell Wall Hydrolase Sle1 in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2017-05-01

    Full Text Available Biofilm causes hospital-associated infections on indwelling medical devices. In Staphylococcus aureus, Biofilm formation is controlled by intricately coordinated network of regulating systems, of which the ATP-dependent protease ClpP shows an inhibitory effect. Here, we demonstrate that the inhibitory effect of ClpP on biofilm formation is through Agr and the cell wall hydrolase Sle1. Biofilm formed by clpP mutant consists of proteins and extracellular DNA (eDNA. The increase of the protein was, at least in part, due to the reduced protease activity of the mutant, which was caused by the decreased activity of agr. On the other hand, the increase of eDNA was due to increased cell lysis caused by the higher level of Sle1. Indeed, as compared with wild type, the clpP mutant excreted an increased level of eDNA, and showed higher sensitivity to Triton-induced autolysis. The deletion of sle1 in the clpP mutant decreased the biofilm formation, the level of eDNA, and the Triton-induced autolysis to wild-type levels. Despite the increased biofilm formation capability, however, the clpP mutant showed significantly reduced virulence in a murine model of subcutaneous foreign body infection, indicating that the increased biofilm formation capability cannot compensate for the intrinsic functions of ClpP during infection.

  6. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how wall...

  7. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how walls...... have encouraged architectural thinking of enclosure, materiality, construction and inhabitation in architectural history, the paper’s aim is to define new directions for the integration of LEDs in walls, challenging the thinking of inhabitation and program. This paper introduces the notion...... of “ambiguous walls” as a more “critical” approach to design [1]. The concept of ambiguous walls refers to the diffuse status a lumious and possibly responsive wall will have. Instead of confining it can open up. Instead of having a static appearance, it becomes a context over time. Instead of being hard...

  8. Protein kinase FgSch9 serves as a mediator of the target of rapamycin and high osmolarity glycerol pathways and regulates multiple stress responses and secondary metabolism in Fusarium graminearum.

    Science.gov (United States)

    Gu, Qin; Zhang, Chengqi; Yu, Fangwei; Yin, Yanni; Shim, Won-Bo; Ma, Zhonghua

    2015-08-01

    Saccharomyces cerevisiae protein kinase Sch9 is one of the downstream effectors of the target of rapamycin (TOR) complex 1 and plays multiple roles in stress resistance, longevity and nutrient sensing. However, the functions of Sch9 orthologs in filamentous fungi, particularly in pathogenic species, have not been characterized to date. Here, we investigated biological and genetic functions of FgSch9 in Fusarium graminearum. The FgSCH9 deletion mutant (ΔFgSch9) was defective in aerial hyphal growth, hyphal branching and conidial germination. The mutant exhibited increased sensitivity to osmotic and oxidative stresses, cell wall-damaging agents, and to rapamycin, while showing increased thermal tolerance. We identified FgMaf1 as one of the FgSch9-interacting proteins that plays an important role in regulating mycotoxin biosynthesis and virulence of F. graminearum. Co-immunoprecipitation and affinity capture-mass spectrometry assays showed that FgSch9 also interacts with FgTor and FgHog1. More importantly, both ΔFgSch9 and FgHog1 null mutant (ΔFgHog1) exhibited increased sensitivity to osmotic and oxidative stresses. This defect was more severe in the FgSch9/FgHog1 double mutant. Taken together, we propose that FgSch9 serves as a mediator of the TOR and high osmolarity glycerol pathways, and regulates vegetative differentiation, multiple stress responses and secondary metabolism in F. graminearum. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  9. The Caenorhabditis elegans RDE-10/RDE-11 complex regulates RNAi by promoting secondary siRNA amplification.

    Science.gov (United States)

    Zhang, Chi; Montgomery, Taiowa A; Fischer, Sylvia E J; Garcia, Susana M D A; Riedel, Christian G; Fahlgren, Noah; Sullivan, Christopher M; Carrington, James C; Ruvkun, Gary

    2012-05-22

    In nematodes, plants, and fungi, RNAi is remarkably potent and persistent due to the amplification of initial silencing signals by RNA-dependent RNA polymerases (RdRPs). In Caenorhabditis elegans (C. elegans), the interaction between the RNA-induced silencing complex (RISC) loaded with primary small interfering RNAs (siRNAs) and the target messenger RNA (mRNA) leads to the recruitment of RdRPs and synthesis of secondary siRNAs using the target mRNA as the template. The mechanism and genetic requirements for secondary siRNA accumulation are not well understood. From a forward genetic screen for C. elegans genes required for RNAi, we identified rde-10, and through proteomic analysis of RDE-10-interacting proteins, we identified a protein complex containing the new RNAi factor RDE-11, the known RNAi factors RSD-2 and ERGO-1, and other candidate RNAi factors. The RNAi defective genes rde-10 and rde-11 encode a novel protein and a RING-type zinc finger domain protein, respectively. Mutations in rde-10 and rde-11 genes cause dosage-sensitive RNAi deficiencies: these mutants are resistant to low dosage but sensitive to high dosage of double-stranded RNAs. We assessed the roles of rde-10, rde-11, and other dosage-sensitive RNAi-defective genes rsd-2, rsd-6, and haf-6 in both exogenous and endogenous small RNA pathways using high-throughput sequencing and qRT-PCR. These genes are required for the accumulation of secondary siRNAs in both exogenous and endogenous RNAi pathways. The RDE-10/RDE-11 complex is essential for the amplification of RNAi in C. elegans by promoting secondary siRNA accumulation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Simulated Microgravity Regulates Gene Transcript Profiles of 2T3 Preosteoblasts: Comparison of the Random Positioning Machine and the Rotating Wall Vessel Bioreactor

    Science.gov (United States)

    Patel, Mamta J.; Liu, Wenbin; Sykes, Michelle C.; Ward, Nancy E.; Risin, Semyon A.; Risin, Diana; Hanjoong, Jo

    2007-01-01

    Microgravity of spaceflight induces bone loss due in part to decreased bone formation by osteoblasts. We have previously examined the microgravity-induced changes in gene expression profiles in 2T3 preosteoblasts using the Random Positioning Machine (RPM) to simulate microgravity conditions. Here, we hypothesized that exposure of preosteoblasts to an independent microgravity simulator, the Rotating Wall Vessel (RWV), induces similar changes in differentiation and gene transcript profiles, resulting in a more confined list of gravi-sensitive genes that may play a role in bone formation. In comparison to static 1g controls, exposure of 2T3 cells to RWV for 3 days inhibited alkaline phosphatase activity, a marker of differentiation, and downregulated 61 genes and upregulated 45 genes by more than two-fold as shown by microarray analysis. The microarray results were confirmed with real time PCR for downregulated genes osteomodulin, bone morphogenic protein 4 (BMP4), runx2, and parathyroid hormone receptor 1. Western blot analysis validated the expression of three downregulated genes, BMP4, peroxiredoxin IV, and osteoglycin, and one upregulated gene peroxiredoxin I. Comparison of the microarrays from the RPM and the RWV studies identified 14 gravi-sensitive genes that changed in the same direction in both systems. Further comparison of our results to a published database showing gene transcript profiles of mechanically loaded mouse tibiae revealed 16 genes upregulated by the loading that were shown to be downregulated by RWV and RPM. These mechanosensitive genes identified by the comparative studies may provide novel insights into understanding the mechanisms regulating bone formation and potential targets of countermeasure against decreased bone formation both in astronauts and in general patients with musculoskeletal disorders.

  11. The role of hexokinases from grape berries (Vitis vinifera L.) in regulating the expression of cell wall invertase and sucrose synthase genes.

    Science.gov (United States)

    Wang, X Q; Li, L M; Yang, P P; Gong, C L

    2014-02-01

    In plants, hexokinase (HXK, EC 2.7.1.1) involved in hexose phosphorylation, plays an important role in sugar sensing and signaling. In this study, we found that at Phase I of grape berry development, lower hexose (glucose or fructose) levels were concomitant with higher HXK activities and protein levels. After the onset of ripening, we demonstrated a drastic reduction in HXK activity and protein levels accompanied by a rising hexose level. Therefore, our results revealed that HXK activity and protein levels had an inverse relationship with the endogenous glucose or fructose levels during grape berry development. A 51 kDa HXK protein band was detected throughout grape berry development. In addition, HXK located in the vacuoles, cytoplasm, nucleus, proplastid, chloroplast, and mitochondrion of the berry flesh cells. During grape berry development, HXK transcriptional level changed slightly, while cell wall invertase (CWINV) and sucrose synthase (SuSy) expression was enhanced after véraison stage. Intriguingly, when sliced grape berries were incubated in different glucose solutions, CWINV and SuSy expression was repressed by glucose, and the intensity of repression depended on glucose concentration and incubation time. After sliced, grape berries were treated with different glucose analogs, CWINV and SuSy expression analyses revealed that phosphorylation of hexoses by hexokinase was an essential component in the glucose-dependent CWINV and SuSy expression. In the meantime, mannoheptulose, a specific inhibitor of hexokinase, blocked the repression induced by glucose on CWINV and SuSy expression. It suggested that HXK played a major role in regulating CWINV and SuSy expression during grape berry development.

  12. Wall Turbulence.

    Science.gov (United States)

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  13. Future Time Perspective, Socio-Emotional Regulation, and Diurnal Cortisol Patterns in Post-Secondary Engineering Students

    Science.gov (United States)

    Cheng, Katherine C.

    2017-01-01

    Built upon Control Value Theory, this dissertation consists of two studies that examine university students' future-oriented motivation, socio-emotional regulation, and diurnal cortisol patterns in understanding students' well-being in the academic-context. Study 1 examined the roles that Learning-related Hopelessness and Future Time Perspective…

  14. Opinions of Secondary School Students on the Effects of Disciplinary Regulations and Practices on the Freedom of Thought and Expression

    Science.gov (United States)

    Taskin, Pelin

    2014-01-01

    Problem Statement: Disciplinary rules are necessary for students to benefit from education and training activities without any problems or shortcomings in the school environment. Governed by a regulation in Turkey, these rules prescribe such penalties as reprimand, short-term suspension, changing of schools or exclusion from formal education…

  15. Genomic and transcriptomic analyses reveal differential regulation of diverse terpenoid and polyketides secondary metabolites in Hericium erinaceus.

    Science.gov (United States)

    Chen, Juan; Zeng, Xu; Yang, Yan Long; Xing, Yong Mei; Zhang, Qi; Li, Jia Mei; Ma, Ke; Liu, Hong Wei; Guo, Shun Xing

    2017-08-31

    The lion's mane mushroom Hericium erinaceus is a famous traditional medicinal fungus credited with anti-dementia activity and a producer of cyathane diterpenoid natural products (erinacines) useful against nervous system diseases. To date, few studies have explored the biosynthesis of these compounds, although their chemical synthesis is known. Here, we report the first genome and tanscriptome sequence of the medicinal fungus H. erinaceus. The size of the genome is 39.35 Mb, containing 9895 gene models. The genome of H. erinaceus reveals diverse enzymes and a large family of cytochrome P450 (CYP) proteins involved in the biosynthesis of terpenoid backbones, diterpenoids, sesquiterpenes and polyketides. Three gene clusters related to terpene biosynthesis and one gene cluster for polyketides biosynthesis (PKS) were predicted. Genes involved in terpenoid biosynthesis were generally upregulated in mycelia, while the PKS gene was upregulated in the fruiting body. Comparative genome analysis of 42 fungal species of Basidiomycota revealed that most edible and medicinal mushroom show many more gene clusters involved in terpenoid and polyketide biosynthesis compared to the pathogenic fungi. None of the gene clusters for terpenoid or polyketide biosynthesis were predicted in the poisonous mushroom Amanita muscaria. Our findings may facilitate future discovery and biosynthesis of bioactive secondary metabolites from H. erinaceus and provide fundamental information for exploring the secondary metabolites in other Basidiomycetes.

  16. Do reciprocal relationships between academic workload and self-regulated learning predict medical freshmen's achievement? A longitudinal study on the educational transition from secondary school to medical school.

    Science.gov (United States)

    Barbosa, Joselina; Silva, Álvaro; Ferreira, Maria Amélia; Severo, Milton

    2018-04-16

    One of the most important factors that makes the transition from secondary school to medical school challenging is the inability to put in the study time that a medical school curriculum demands. The implementation of regulated learning is essential for students to cope with medical course environment and succeed. This study aimed to investigate the reciprocal relationships between self-regulated learning skills (SRLS) and academic workload (AW) across secondary school to medical school transition. Freshmen enrolled in medical school (N = 102) completed questionnaires at the beginning and at the end of their academic year, assessing AW (measured as study time hours and perceived workload), SRLS (planning and strategies for learning assessment, motivation and action to learning and self-directedness) and academic achievement. An exploratory factor analysis (EFA) and a longitudinal path analysis were performed. According to the EFA, study time and perceived workload revealed two factors of AW: students who had a high perceived workload also demonstrated increased study time (tandem AW); and those who had a low perceived workload also demonstrated increased study time (inverse AW). Only a longitudinal relationship between SRLS and AW was found in the path analysis: prior self-directedness was related to later tandem AW. Moreover, success during the first year of medical school is dependent on exposure to motivation, self-directedness and high study time without overload during secondary school and medical school, and prior academic achievement. By better understanding these relationships, teachers can create conditions that support academic success during the first year medical school.

  17. Rocks and walls: natural versus secondary habitats

    Czech Academy of Sciences Publication Activity Database

    Láníková, Deana; Lososová, Z.

    2009-01-01

    Roč. 44, č. 3 (2009), s. 263-280 ISSN 1211-9520 R&D Projects: GA ČR GA206/09/0329 Institutional research plan: CEZ:AV0Z60050516 Keywords : alien species * chasmophytic vegetation * diversity Subject RIV: EF - Botanics Impact factor: 1.320, year: 2009

  18. Stabilizing plug-and-play regulators and secondary coordinated control for AC islanded microgrids with bus-connected topology

    DEFF Research Database (Denmark)

    Riverso, Stefano; Tucci, Michele; Vasquez, Juan C.

    2018-01-01

    on the corresponding voltage-source converter. Following the plug-and-play design approach previously proposed by some of the authors, whenever the addition/removal of a distributed generation unit is required, feasibility of the operation is automatically checked by designing local controllers through convex...... is distributed, hence mirroring the modularity of the primary control layer. We validate primary and secondary controllers by performing experiments with both linear and nonlinear loads, on a setup composed of three bus-connected distributed generation units. Most importantly, the stability of the microgrid...... after the addition/removal of distributed generation units is assessed. Overall, the experimental results show the feasibility of the proposed modular control design framework, where generation units can be added/removed on the fly, thus enabling the deployment of virtual power plants that can...

  19. Systematically reviewing the potential of concept mapping technologies to promote self-regulated learning in primary and secondary science education

    DEFF Research Database (Denmark)

    Stevenson, Matt P.; Hartmeyer, Rikke; Bentsen, Peter

    2017-01-01

    We systematically searched five databases to assess the potential of concept mapping-based technologies to promote self-regulated learning in science education. Our search uncovered 17 relevant studies that investigated seven different types of learning technologies. We performed a narrative....... Computer software was particularly useful for developing cognitive strategies through ease of use. Teaching agents were particularly useful for developing metacognitive strategies by coupling visualisation of knowledge patterns with performance monitoring, aided by a teaching metaphor. Finally, mobile...... devices and teaching agents were most effective in enhancing motivation. Effects on knowledge gains remain unclear due to small sample sizes....

  20. Design Rationale Behind the Serious Self-Regulation Game Intervention "Balance It": Overweight Prevention Among Secondary Vocational Education Students in The Netherlands.

    Science.gov (United States)

    Spook, Jorinde E; Paulussen, Theo; Paulissen, Rosie; Visschedijk, Gillian; Kok, Gerjo; van Empelen, Pepijn

    2015-10-01

    This article describes the design rationale behind a serious self-regulation game intervention. The aim of the game is to promote healthy dietary intake and physical activity among secondary vocational educational students in The Netherlands (approximately 16-20 years of age). The game "Balance It" was developed according to an intervention mapping (IM) protocol. Following IM, we specified health promotion and usability objectives and linked these objectives to selected behavior change and persuasive methods. Accordingly, these methods were translated into a coherent intervention program. The health behavior change objectives were derived from the determinants of the behavior and from Self-Regulation Theory (e.g., students are asked to set goals, monitor and evaluate their behavior, and create coping plans). Usability objectives were derived from the RE-AIM model (i.e., Reach, Effectiveness, Adoption, Implementation, and Maintenance). Next, behavior change and persuasive techniques were selected (e.g., goal setting and prompting, respectively) that did fit with the targeted change objectives and were translated in the design of a (mobile) serious self-regulation game intervention. Subsequently, three concept and usability tests were performed to improve intervention usability, and an evaluation plan was developed. The aim of this study was to provide a design rationale for game interventions targeting health-related behaviors. We developed a coherent program design in which both health behavior change and usability factors are addressed. The IM protocol can serve as a useful guide for decision making in program development and evaluation.

  1. The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California

    Energy Technology Data Exchange (ETDEWEB)

    Maher, K.; Steefel, C. I.; White, A.F.; Stonestrom, D.A.

    2009-02-25

    In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka marine terrace chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized (White et al., 2008, GCA) and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisser and [2006] or the aluminum inhibition model proposed by Oelkers et al. [1994], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Observed maximum clay abundances in the argillic horizons occur at the depth and time where the reaction fronts of the primary minerals overlap. The modeling indicates that the argillic horizon at Santa Cruz can be explained almost entirely by weathering of primary minerals and in situ clay precipitation accompanied by undersaturation of kaolinite at the top of the profile. The rate constant for kaolinite precipitation was also determined based on model simulations of mineral abundances and dissolved Al, SiO{sub 2}(aq) and pH in pore waters. Changes in the rate of kaolinite precipitation or the flow rate do not affect the gradient of the primary mineral weathering profiles, but instead control the rate of propagation of the primary mineral weathering fronts and thus total

  2. ABA and GA3 regulate the synthesis of primary and secondary metabolites related to alleviation from biotic and abiotic stresses in grapevine.

    Science.gov (United States)

    Murcia, Germán; Fontana, Ariel; Pontin, Mariela; Baraldi, Rita; Bertazza, Gianpaolo; Piccoli, Patricia N

    2017-03-01

    Plants are able to synthesize a large number of organic compounds. Among them, primary metabolites are known to participate in plant growth and development, whereas secondary metabolites are mostly involved in defense and other facultative processes. In grapevine, one of the major fruit crops in the world, secondary metabolites, mainly polyphenols, are of great interest for the wine industry. Even though there is an extensive literature on the content and profile of those compounds in berries, scarce or no information is available regarding polyphenols in other organs. In addition, little is known about the effect of plant growth regulators (PGRs), ABA and GA 3 (extensively used in table grapes) on the synthesis of primary and secondary metabolites in wine grapes. In table grapes, cultural practices include the use of GA 3 sprays shortly before veraison, to increase berry and bunch size, and sugar content in fruits. Meanwhile, ABA applications to the berries on pre-veraison improve the skin coloring and sugar accumulation, anticipating the onset of veraison. Accordingly, the aim of this study was to assess and characterize primary and secondary metabolites in leaves, berries and roots of grapevine plants cv. Malbec at veraison, and changes in compositions after ABA and GA 3 aerial sprayings. Metabolic profiling was conducted using GC-MS, GC-FID and HPLC-MWD. A large set of metabolites was identified: sugars, alditols, organic acids, amino acids, polyphenols (flavonoids and non-flavonoids) and terpenes (mono-, sesqui-, di- and triterpenes). The obtained results showed that ABA applications elicited synthesis of mono- and sesquiterpenes in all assessed tissues, as well as L-proline, acidic amino acids and anthocyanins in leaves. Additionally, applications with GA 3 elicited synthesis of L-proline in berries, and mono- and sesquiterpenes in all the tissues. However, treatment with GA 3 seemed to block polyphenol synthesis, mainly in berries. In conclusion, ABA and GA

  3. Secondary and sucrose metabolism regulated by different light quality combinations involved in melon tolerance to powdery mildew.

    Science.gov (United States)

    Jing, Xin; Wang, Hui; Gong, Biao; Liu, Shiqi; Wei, Min; Ai, Xizhen; Li, Yan; Shi, Qinghua

    2018-03-01

    We evaluated the effect of different light combinations on powdery mildew resistance and growth of melon seedlings. Light-emitting diodes were used as the light source and there were five light combinations: white light (420-680 nm); blue light (460 nm); red light (635 nm); RB31 (ratio of red and blue light, 3: 1); and RB71 (ratio of red and blue light, 7: 1). Compared with other treatments, blue light significantly decreased the incidence of powdery mildew in leaves of melon seedlings. Under blue light, H 2 O 2 showed higher accumulation, and the content of phenolics, flavonoid and tannins, as well as expression of the genes involved in synthesis of these substances, significantly increased compared with other treatments before and after infection. Lignin content and expression of the genes related to its synthesis were also induced by blue light before infection. Melon irradiated with RB31 light showed the best growth parameters. Compared with white light, red light and RB71, RB31 showed higher accumulation of lignin and lower incidence of powdery mildew. We conclude that blue light increases melon resistance to powdery mildew, which is dependent on the induction of secondary metabolism that may be related to H 2 O 2 accumulation before infection. Induction of tolerance of melon seeds to powdery mildew by RB31 is due to higher levels of sucrose metabolism and accumulation of lignin. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  4. The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California

    Science.gov (United States)

    Maher, K.; Steefel, Carl; White, A.F.; Stonestrom, David A.

    2009-01-01

    In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation, and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka Marine Terrace Chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized [White A. F., Schulz M. S., Vivit D. V., Blum A., Stonestrom D. A. and Anderson S. P. (2008) Chemical weathering of a Marine Terrace Chronosequence, Santa Cruz, California. I: interpreting the long-term controls on chemical weathering based on spatial and temporal element and mineral distributions. Geochim. Cosmochim. Acta 72 (1), 36-68] and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisserand [Hellmann R. and Tisserand D. (2006) Dissolution kinetics as a function of the Gibbs free energy of reaction: An experimental study based on albite feldspar. Geochim. Cosmochim. Acta 70 (2), 364-383] or the aluminum inhibition model proposed by Oelkers et al. [Oelkers E. H., Schott J. and Devidal J. L. (1994) The effect of aluminum, pH, and chemical affinity on the rates of aluminosilicate dissolution reactions. Geochim. Cosmochim. Acta 58 (9), 2011-2024], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Additionally, observed maximum clay abundances in the argillic horizons occur at

  5. Deciphering the Cryptic Genome: Genome-wide Analyses of the Rice Pathogen Fusarium fujikuroi Reveal Complex Regulation of Secondary Metabolism and Novel Metabolites

    Science.gov (United States)

    Studt, Lena; Niehaus, Eva-Maria; Espino, Jose J.; Huß, Kathleen; Michielse, Caroline B.; Albermann, Sabine; Wagner, Dominik; Bergner, Sonja V.; Connolly, Lanelle R.; Fischer, Andreas; Reuter, Gunter; Kleigrewe, Karin; Bald, Till; Wingfield, Brenda D.; Ophir, Ron; Freeman, Stanley; Hippler, Michael; Smith, Kristina M.; Brown, Daren W.; Proctor, Robert H.; Münsterkötter, Martin; Freitag, Michael; Humpf, Hans-Ulrich; Güldener, Ulrich; Tudzynski, Bettina

    2013-01-01

    The fungus Fusarium fujikuroi causes “bakanae” disease of rice due to its ability to produce gibberellins (GAs), but it is also known for producing harmful mycotoxins. However, the genetic capacity for the whole arsenal of natural compounds and their role in the fungus' interaction with rice remained unknown. Here, we present a high-quality genome sequence of F. fujikuroi that was assembled into 12 scaffolds corresponding to the 12 chromosomes described for the fungus. We used the genome sequence along with ChIP-seq, transcriptome, proteome, and HPLC-FTMS-based metabolome analyses to identify the potential secondary metabolite biosynthetic gene clusters and to examine their regulation in response to nitrogen availability and plant signals. The results indicate that expression of most but not all gene clusters correlate with proteome and ChIP-seq data. Comparison of the F. fujikuroi genome to those of six other fusaria revealed that only a small number of gene clusters are conserved among these species, thus providing new insights into the divergence of secondary metabolism in the genus Fusarium. Noteworthy, GA biosynthetic genes are present in some related species, but GA biosynthesis is limited to F. fujikuroi, suggesting that this provides a selective advantage during infection of the preferred host plant rice. Among the genome sequences analyzed, one cluster that includes a polyketide synthase gene (PKS19) and another that includes a non-ribosomal peptide synthetase gene (NRPS31) are unique to F. fujikuroi. The metabolites derived from these clusters were identified by HPLC-FTMS-based analyses of engineered F. fujikuroi strains overexpressing cluster genes. In planta expression studies suggest a specific role for the PKS19-derived product during rice infection. Thus, our results indicate that combined comparative genomics and genome-wide experimental analyses identified novel genes and secondary metabolites that contribute to the evolutionary success of F

  6. The MAPKK FgMkk1 of Fusarium graminearum regulates vegetative differentiation, multiple stress response, and virulence via the cell wall integrity and high-osmolarity glycerol signaling pathways.

    Science.gov (United States)

    Yun, Yingzi; Liu, Zunyong; Zhang, Jingze; Shim, Won-Bo; Chen, Yun; Ma, Zhonghua

    2014-07-01

    Mitogen-activated protein (MAP) kinases play crucial roles in regulating fungal development, growth and pathogenicity, and in responses to the environment. In this study, we characterized a MAP kinase kinase FgMkk1 in Fusarium graminearum, the causal agent of wheat head blight. Phenotypic analyses of the FgMKK1 mutant (ΔFgMKK1) showed that FgMkk1 is involved in the regulation of hyphal growth, pigmentation, conidiation, deoxynivalenol biosynthesis and virulence of F. graminearum. ΔFgMKK1 also showed increased sensitivity to cell wall-damaging agents, and to osmotic and oxidative stresses, but exhibited decreased sensitivity to the fungicides iprodione and fludioxonil. In addition, the mutant revealed increased sensitivity to a biocontrol agent, Trichoderma atroviride. Western blot assays revealed that FgMkk1 positively regulates phosphorylation of the MAP kinases Mgv1 and FgOs-2, the key component in the cell wall integrity (CWI) and high-osmolarity glycerol (HOG) signalling pathway respectively. Yeast two-hybrid assay indicated that Mgv1 interacts with a transcription factor FgRlm1. The FgRLM1 mutant (ΔFgRLM1) showed increased sensitivity to cell wall-damaging agents and exhibited decreased virulence. Taken together, our data indicated that FgMkk1 is an upstream component of Mgv1, and regulates vegetative differentiation, multiple stress response and virulence via the CWI and HOG signalling pathways. FgRlm1 may be a downstream component of Mgv1 in the CWI pathway in F. graminearum. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Secondary Hypertension

    Science.gov (United States)

    Secondary hypertension Overview Secondary hypertension (secondary high blood pressure) is high blood pressure that's caused by another medical condition. Secondary hypertension can be caused by conditions that affect your kidneys, ...

  8. Not an 'iron pipeline', but many capillaries: regulating passive transactions in Los Angeles' secondary, illegal gun market.

    Science.gov (United States)

    Chesnut, Kelsie Y; Barragan, Melissa; Gravel, Jason; Pifer, Natalie A; Reiter, Keramet; Sherman, Nicole; Tita, George E

    2017-08-01

    California has strict firearm-related laws and is exceptional in its regulation of firearms retailers. Though evidence suggests that these laws can reduce illegal access to guns, high levels of gun violence persist in Los Angeles (LA), California. This research seeks to describe the sources of guns accessed by active offenders in LA, California and reports offenders' motivations for obtaining guns. Los Angeles County Jail (LACJ) system (four facilities). Random sampling from a screened pool of eligible participants was used to conduct qualitative semistructured interviews with 140 incarcerated gun offenders in one of four (LACJ) facilities. Researchers collected data on firearm acquisition, experiences related to gun violence, and other topics, using a validated survey instrument. Grounded theory guided the collection and analysis of data. Respondents reported possession of 77 specific guns (79.2% handguns) collectively. Social networks facilitate access to illegal guns; the majority of interviewees acquired their illegal guns through a social connection (85.7%) versus an outside broker/unregulated retailer (8.5%). Most guns were obtained through illegal purchase (n=51) or gift (n=15). A quarter of gun purchasers report engaging in a passive transaction, or one initiated by another party. Passive gun buyers were motivated by concerns for personal safety and/or economic opportunity. In LA's illegal gun market, where existing social relationships facilitate access to guns across a diffuse network, individuals, influenced by both fear and economic opportunity, have frequent opportunities to illegally possess firearms through passive transactions. Gun policies should better target and minimise these transactions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. The AreA transcription factor in Fusarium graminearum regulates the use of some nonpreferred nitrogen sources and secondary metabolite production.

    Science.gov (United States)

    Giese, Henriette; Sondergaard, Teis Esben; Sørensen, Jens Laurids

    2013-01-01

    Growth conditions are known to affect the production of secondary metabolites in filamentous fungi. The influence of different nitrogen sources and the transcription factor AreA on the production of mycotoxins in Fusarium graminearum was examined. Growth on glutamine or NH4-sources was poor and asparagine was found to be a preferential nitrogen source for F. graminearum. Deletion of areA led to poor growth on NaNO₃ suggesting its involvement in regulation of the nitrate reduction process. In addition utilization of aspartic acid, histidine, isoleucine, leucine, threonine, tyrosine, and valine as nitrogen sources was shown to depend of a functional AreA. AreA was shown to be required for the production of the mycotoxins deoxynivalenol (DON), zearalenone, and fusarielin H regardless of the nutrient medium. Deletion of nmr, the repressor of AreA under nitrogen sufficient conditions, had little effect on either growth or toxin production. AreA appears to regulate production of some mycotoxins directly or indirectly independent on nitrogen status and plays a role in utilization of certain amino acids. Copyright © 2013 The British Mycological Society. All rights reserved.

  10. Involvement of a velvet protein FgVeA in the regulation of asexual development, lipid and secondary metabolisms and virulence in Fusarium graminearum.

    Directory of Open Access Journals (Sweden)

    Jinhua Jiang

    Full Text Available The velvet protein, VeA, is involved in the regulation of diverse cellular processes. In this study, we explored functions of FgVeA in the wheat head blight pathogen, Fusarium graminearum,using a gene replacement strategy. The FgVEA deletion mutant exhibited a reduction in aerial hyphae formation, hydrophobicity, and deoxynivalenol (DON biosynthesis. Deletion of FgVEA gene led to an increase in conidial production, but a delay in conidial germination. Pathogencity assays showed that the mutant was impaired in virulence on flowering wheat head. Sensitivity tests to various stresses exhibited that the FgVEA deletion mutant showed increased resistance to osmotic stress and cell wall-damaging agents, but increased sensitivity to iprodione and fludioxonil fungicides. Ultrastructural and histochemical analyses revealed that conidia of FgVeA deletion mutant contained an unusually high number of large lipid droplets, which is in agreement with the observation that the mutant accumulated a higher basal level of glycerol than the wild-type progenitor. Serial analysis of gene expression (SAGE in the FgVEA mutant confirmed that FgVeA was involved in various cellular processes. Additionally, six proteins interacting with FgVeA were identified by yeast two hybrid assays in current study. These results indicate that FgVeA plays a critical role in a variety of cellular processes in F. graminearum.

  11. Associations between state regulations, training length, perceived quality and job satisfaction among certified nursing assistants: cross-sectional secondary data analysis.

    Science.gov (United States)

    Han, Kihye; Trinkoff, Alison M; Storr, Carla L; Lerner, Nancy; Johantgen, Meg; Gartrell, Kyungsook

    2014-08-01

    In the U.S., there are federal requirements on how much training and annual continuing education a certified nursing assistant must complete in order to be certified. The requirements are designed to enable them to provide competent and quality care to nursing home residents. Many states also require additional training and continuing education hours as improved nursing home quality indicators have been found to be related to increased training. This study investigated the associations among state level regulations, initial training quality and focus, and job satisfaction in certified nursing assistants. Cross-sectional secondary data analysis. This study used the National Nursing Home Survey and National Nursing Assistant Survey as well as data on state regulations of certified nursing assistant training. 2897 certified nursing assistants in 580 nursing homes who were currently working at a nursing home facility, who represented 680,846 certified nursing assistants in US. State regulations were related to initial training and job satisfaction among certified nursing assistants using chi square tests and binomial logistic regression models. Analyses were conducted using SAS-callable SUDAAN to correct for complex sampling design effects in the National Nursing Home Survey and National Nursing Assistant Survey. Models were adjusted for personal and facility characteristics. Certified nursing assistants reporting high quality training were more likely to work in states requiring additional initial training hours (p=0.02) and were more satisfied with their jobs (OR=1.51, 95% CI=1.09-2.09) than those with low quality training. In addition, those with more training focused on work life skills were 91% more satisfied (OR=1.91, 95% CI=1.41-2.58) whereas no relationship was found between training focused on basic care skills and job satisfaction (OR=1.36, 95% CI=0.99-1.84). Certified nursing assistants with additional initial training were more likely to report that their

  12. The PacC transcription factor regulates secondary metabolite production and stress response, but has only minor effects on virulence in the insect pathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Luo, Zhibing; Ren, Hui; Mousa, Jarrod J; Rangel, Drauzio E N; Zhang, Yongjun; Bruner, Steven D; Keyhani, Nemat O

    2017-02-01

    The PacC transcription factor is an important component of the fungal ambient pH-responsive regulatory system. Loss of pacC in the insect pathogenic fungus Beauveria bassiana resulted in an alkaline pH-dependent decrease in growth and pH-dependent increased susceptibility to osmotic (salt, sorbitol) stress and SDS. Extreme susceptibility to Congo Red was noted irrespective of pH, and ΔBbpacC conidia showed subtle increases in UV susceptibility. The ΔBbPacC mutant showed a reduced ability to acidify media during growth due to failure to produce oxalic acid. The ΔBbPacC mutant also did not produce the insecticidal compound dipicolinic acid, however, production of a yellow-colored compound was noted. The compound, named bassianolone B, was purified and its structure determined. Despite defects in growth, stress resistance, and oxalate/insecticidal compound production, only a small decrease in virulence was seen for the ΔBbpacC strain in topical insect bioassays using larvae from the greater waxmoth, Galleria mellonella or adults of the beetle, Tenebrio molitor. However, slightly more pronounced decreases were seen in virulence via intrahemcoel injection assays (G. mellonella) and in assays using T. molitor larvae. These data suggest important roles for BbpacC in mediating growth at alkaline pH, regulating secondary metabolite production, and in targeting specific insect stages. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Regulation

    International Nuclear Information System (INIS)

    Ballereau, P.

    1999-01-01

    The different regulations relative to nuclear energy since the first of January 1999 are given here. Two points deserve to be noticed: the decree of the third august 1999 authorizing the national Agency for the radioactive waste management to install and exploit on the commune of Bures (Meuse) an underground laboratory destined to study the deep geological formations where could be stored the radioactive waste. The second point is about the uranium residues and the waste notion. The judgment of the administrative tribunal of Limoges ( 9. july 1998) forbidding the exploitation of a storage installation of depleted uranium considered as final waste and qualifying it as an industrial waste storage facility has been annulled bu the Court of Appeal. It stipulated that, according to the law number 75663 of the 15. july 1965, no criteria below can be applied to depleted uranium: production residue (possibility of an ulterior enrichment), abandonment of a personal property or simple intention to do it ( future use aimed in the authorization request made in the Prefecture). This judgment has devoted the primacy of the waste notion on this one of final waste. (N.C.)

  14. A new mechanism for the regulation of stomatal aperture size in intact leaves: accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba

    International Nuclear Information System (INIS)

    Lu, P.; Outlaw, W.H. Jr.; Smith, B.G.; Freed, G.A.

    1997-01-01

    At various times after pulse-labeling broad bean (Vicia faba L.) leaflets with 14CO2, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents, whereas those from rinsed peels contained only symplastic contents. Sucrose (Suc)-specific radioactivity peaked (111 GBq mol-1) in palisade cells at 20 min. In contrast, the 14C content and Suc-specific radioactivity were very low in guard cells for 20 min, implying little CO2 incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum Suc-specific radioactivity (204 GBq mol-1) and a high Suc influx rate (0.05 pmol stoma-1 min-1). These and other comparisons implied the presence of (a) multiple Suc pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived Suc in guard-cell walls sufficient to diminish stomatal opening by approximately 3 micrometers. Factors expected to enhance Suc accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic Suc concentration, which is elevated when mesophyll Suc efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal aperture size by this previously unrecognized mechanism

  15. Longevity in vivo of primary cell wall cellulose synthases.

    Science.gov (United States)

    Hill, Joseph Lee; Josephs, Cooper; Barnes, William J; Anderson, Charles T; Tien, Ming

    2018-02-01

    Our work focuses on understanding the lifetime and thus stability of the three main cellulose synthase (CESA) proteins involved in primary cell wall synthesis of Arabidopsis. It had long been thought that a major means of CESA regulation was via their rapid degradation. However, our studies here have uncovered that AtCESA proteins are not rapidly degraded. Rather, they persist for an extended time in the plant cell. Plant cellulose is synthesized by membrane-embedded cellulose synthase complexes (CSCs). The CSC is composed of cellulose synthases (CESAs), of which three distinct isozymes form the primary cell wall CSC and another set of three isozymes form the secondary cell wall CSC. We determined the stability over time of primary cell wall (PCW) CESAs in Arabidopsis thaliana seedlings, using immunoblotting after inhibiting protein synthesis with cycloheximide treatment. Our work reveals very slow turnover for the Arabidopsis PCW CESAs in vivo. Additionally, we show that the stability of all three CESAs within the PCW CSC is altered by mutations in individual CESAs, elevated temperature, and light conditions. Together, these results suggest that CESA proteins are very stable in vivo, but that their lifetimes can be modulated by intrinsic and environmental cues.

  16. Diurnal Periodicity in the Supply of Cell Wall Components during Wood Cell Wall Formation

    OpenAIRE

    細尾, 佳宏

    2012-01-01

    This review summarizes recent studies on the diurnal periodicity in wood cell wall formation, with a major focus on those that we have conducted. Differences in the innermost surface of developing secondary walls of differentiating conifer tracheids can be seen from day to night Cellulose microfibrils are clearly evident during the day, and amorphous material containing abundant hemicelluloses is prevalent at night. These findings suggest a diurnal periodicity in the supply of cell wall compo...

  17. Up-regulation of T lymphocyte and antibody production by inflammatory cytokines released by macrophage exposure to multi-walled carbon nanotubes

    Science.gov (United States)

    Grecco, Ana Carolina P.; Paula, Rosemeire F. O.; Mizutani, Erica; Sartorelli, Juliana C.; Milani, Ana M.; Longhini, Ana Leda F.; Oliveira, Elaine C.; Pradella, Fernando; Silva, Vania D. R.; Moraes, Adriel S.; Peterlevitz, Alfredo C.; Farias, Alessandro S.; Ceragioli, Helder J.; Santos, Leonilda M. B.; Baranauskas, Vitor

    2011-07-01

    Our data demonstrate that multi-walled carbon nanotubes (MWCNTs) are internalized by macrophages, subsequently activating them to produce interleukin (IL)-12 (IL-12). This cytokine induced the proliferative response of T lymphocytes to a nonspecific mitogen and to ovalbumin (OVA). This increase in the proliferative response was accompanied by an increase in the expression of pro-inflammatory cytokines, such as interferon-gamma (IFNγ), tumor necrosis factor-alpha (TNFα) and IL-6, in mice inoculated with MWCNTs, whether or not they had been immunized with OVA. A decrease in the expression of transforming growth factor-beta (TGFβ) was observed in the mice treated with MWCNTs, whereas the suppression of the expression of both TGFβ and IL-10 was observed in mice that had been both treated and immunized. The activation of the T lymphocyte response by the pro-inflammatory cytokines leads to an increase in antibody production to OVA, suggesting the important immunostimulatory effect of carbon nanotubes.

  18. First wall

    International Nuclear Information System (INIS)

    Omori, Junji.

    1991-01-01

    Graphite and C/C composite are used recently for the first wall of a thermonuclear device since materials with small atom number have great impurity allowable capacity for plasmas. Among them, those materials having high thermal conduction are generally anisotropic and have an upper limit for the thickness upon production. Then, anisotropic materials are used for a heat receiving plate, such that the surfaces of the heat receiving plate on the side of lower heat conductivity are brought into contact with each other, and the side of higher thermal conductivity is arranged in parallel with small radius direction and the toroidal direction of the thermonuclear device. As a result, the incident heat on an edge portion can be transferred rapidly to the heat receiving plate, which can suppress the temperature elevation at the surface to thereby reduce the amount of abrasion. Since the heat expansion coefficient of the anisotropic materials is great in the direction of the lower heat conductivity and small in the direction of the higher heat conductivity, the gradient of a thermal load distribution in the direction of the higher heat expansion coefficient is small, and occurrence of thermal stresses due to temperature difference is reduced, to improve the reliability. (N.H.)

  19. Falling walls

    CERN Multimedia

    It was 20 years ago this week that the Berlin wall was opened for the first time since its construction began in 1961. Although the signs of a thaw had been in the air for some time, few predicted the speed of the change that would ensue. As members of the scientific community, we can take a moment to reflect on the role our field played in bringing East and West together. CERN’s collaboration with the East, primarily through links with the Joint Institute for Nuclear Research, JINR, in Dubna, Russia, is well documented. Less well known, however, is the role CERN played in bringing the scientists of East and West Germany together. As the Iron curtain was going up, particle physicists on both sides were already creating the conditions that would allow it to be torn down. Cold war historian Thomas Stange tells the story in his 2002 CERN Courier article. It was my privilege to be in Berlin on Monday, the anniversary of the wall’s opening, to take part in a conference entitled &lsquo...

  20. Up-regulation of T lymphocyte and antibody production by inflammatory cytokines released by macrophage exposure to multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Grecco, Ana Carolina P; Mizutani, Erica; Peterlevitz, Alfredo C; Ceragioli, Helder J; Baranauskas, Vitor [Faculdade de Engenharia Eletrica e Computacao, Universidade de Campinas, Campinas, SP (Brazil); Paula, Rosemeire F O; Sartorelli, Juliana C; Milani, Ana M; Longhini, Ana Leda F; Oliveira, Elaine C; Pradella, Fernando; Silva, Vania D R; Moraes, Adriel S; Farias, Alessandro S; Santos, Leonilda M B, E-mail: leonilda@unicamp.br [Laboratorio de Neuroimunologia, Departamento Genetica, Evolucao e Bioagentes, Instituto de Biologia, Universidade de Campinas, Campinas, SP (Brazil)

    2011-07-01

    Our data demonstrate that multi-walled carbon nanotubes (MWCNTs) are internalized by macrophages, subsequently activating them to produce interleukin (IL)-12 (IL-12). This cytokine induced the proliferative response of T lymphocytes to a nonspecific mitogen and to ovalbumin (OVA). This increase in the proliferative response was accompanied by an increase in the expression of pro-inflammatory cytokines, such as interferon-gamma (IFN{gamma}), tumor necrosis factor-alpha (TNF{alpha}) and IL-6, in mice inoculated with MWCNTs, whether or not they had been immunized with OVA. A decrease in the expression of transforming growth factor-beta (TGF{beta}) was observed in the mice treated with MWCNTs, whereas the suppression of the expression of both TGF{beta} and IL-10 was observed in mice that had been both treated and immunized. The activation of the T lymphocyte response by the pro-inflammatory cytokines leads to an increase in antibody production to OVA, suggesting the important immunostimulatory effect of carbon nanotubes.

  1. Isolation of the Cell Wall.

    Science.gov (United States)

    Canut, Hervé; Albenne, Cécile; Jamet, Elisabeth

    2017-01-01

    This chapter describes a method allowing the purification of the cell wall for studying both polysaccharides and proteins. The plant primary cell wall is mainly composed of polysaccharides (90-95 % in mass) and of proteins (5-10 %). At the end of growth, specialized cells may synthesize a lignified secondary wall composed of polysaccharides (about 65 %) and lignin (about 35 %). Due to its composition, the cell wall is the cellular compartment having the highest density and this property is used for its purification. It plays critical roles during plant development and in response to environmental constraints. It is largely used in the food and textile industries as well as for the production of bioenergy. All these characteristics and uses explain why its study as a true cell compartment is of high interest. The proposed method of purification can be used for large amount of material but can also be downscaled to 500 mg of fresh material. Tools for checking the quality of the cell wall preparation, such as protein analysis and microscopy observation, are also provided.

  2. KdmB, a Jumonji Histone H3 Demethylase, Regulates Genome-Wide H3K4 Trimethylation and Is Required for Normal Induction of Secondary Metabolism in Aspergillus nidulans.

    Directory of Open Access Journals (Sweden)

    Agnieszka Gacek-Matthews

    2016-08-01

    Full Text Available Histone posttranslational modifications (HPTMs are involved in chromatin-based regulation of fungal secondary metabolite biosynthesis (SMB in which the corresponding genes-usually physically linked in co-regulated clusters-are silenced under optimal physiological conditions (nutrient-rich but are activated when nutrients are limiting. The exact molecular mechanisms by which HPTMs influence silencing and activation, however, are still to be better understood. Here we show by a combined approach of quantitative mass spectrometry (LC-MS/MS, genome-wide chromatin immunoprecipitation (ChIP-seq and transcriptional network analysis (RNA-seq that the core regions of silent A. nidulans SM clusters generally carry low levels of all tested chromatin modifications and that heterochromatic marks flank most of these SM clusters. During secondary metabolism, histone marks typically associated with transcriptional activity such as H3 trimethylated at lysine-4 (H3K4me3 are established in some, but not all gene clusters even upon full activation. KdmB, a Jarid1-family histone H3 lysine demethylase predicted to comprise a BRIGHT domain, a zinc-finger and two PHD domains in addition to the catalytic Jumonji domain, targets and demethylates H3K4me3 in vivo and mediates transcriptional downregulation. Deletion of kdmB leads to increased transcription of about ~1750 genes across nutrient-rich (primary metabolism and nutrient-limiting (secondary metabolism conditions. Unexpectedly, an equally high number of genes exhibited reduced expression in the kdmB deletion strain and notably, this group was significantly enriched for genes with known or predicted functions in secondary metabolite biosynthesis. Taken together, this study extends our general knowledge about multi-domain KDM5 histone demethylases and provides new details on the chromatin-level regulation of fungal secondary metabolite production.

  3. Analysis of secondary motions in square duct flow

    Science.gov (United States)

    Modesti, Davide; Pirozzoli, Sergio; Orlandi, Paolo; Grasso, Francesco

    2018-04-01

    We carry out direct numerical simulations (DNS) of square duct flow spanning the friction Reynolds number range {Re}τ * =150-1055, to study the nature and the role of secondary motions. We preliminarily find that secondary motions are not the mere result of the time averaging procedure, but rather they are present in the instantaneous flow realizations, corresponding to large eddies persistent in both space and time. Numerical experiments have also been carried out whereby the secondary motions are suppressed, hence allowing to quantifying their effect on the mean flow field. At sufficiently high Reynolds number, secondary motions are found to increase the friction coefficient by about 3%, hence proportionally to their relative strength with respect to the bulk flow. Simulations without secondary motions are found to yield larger deviations on the mean velocity profiles from the standard law-of-the-wall, revealing that secondary motions act as a self-regulating mechanism of turbulence whereby the effect of the corners is mitigated.

  4. Inter-species investigation of the mechano-regulation of bone healing: comparison of secondary bone healing in sheep and rat.

    Science.gov (United States)

    Checa, Sara; Prendergast, Patrick J; Duda, Georg N

    2011-04-29

    Inter-species differences in regeneration exist in various levels. One aspect is the dynamics of bone regeneration and healing, e.g. small animals show a faster healing response when compared to large animals. Mechanical as well as biological factors are known to play a key role in the process. However, it remains so far unknown whether different animals follow at all comparable mechano-biological rules during tissue regeneration, and in particular during bone healing. In this study, we investigated whether differences observed in vivo in the dynamics of bone healing between rat and sheep are only due to differences in the animal size or whether these animals have a different mechano-biological response during the healing process. Histological sections from in vivo experiments were compared to in silico predictions of a mechano-biological computer model for the simulation of bone healing. Investigations showed that the healing processes in both animal models occur under significantly different levels of mechanical stimuli within the callus region, which could explain histological observations of early intramembranous ossification at the endosteal side. A species-specific adaptation of a mechano-biological model allowed a qualitative match of model predictions with histological observations. Specifically, when keeping cell activity processes at the same rate, the amount of tissue straining defining favorable mechanical conditions for the formation of bone had to be increased in the large animal model, with respect to the small animal, to achieve a qualitative agreement of model predictions with histological data. These findings illustrate that geometrical (size) differences alone cannot explain the distinctions seen in the histological appearance of secondary bone healing in sheep and rat. It can be stated that significant differences in the mechano-biological regulation of the healing process exist between these species. Future investigations should aim towards

  5. A gene expression analysis of cell wall biosynthetic genes in Malus × domestica infected by ‘Candidatus Phytoplasma mali’

    Science.gov (United States)

    Guerriero, Gea; Giorno, Filomena; Ciccotti, Anna Maria; Schmidt, Silvia; Baric, Sanja

    2016-01-01

    Apple proliferation (AP) represents a serious threat to several fruit-growing areas and is responsible for great economic losses. Several studies have highlighted the key role played by the cell wall in response to pathogen attack. The existence of a cell wall integrity signaling pathway which senses perturbations in the cell wall architecture upon abiotic/biotic stresses and activates specific defence responses has been widely demonstrated in plants. More recently a role played by cell wall-related genes has also been reported in plants infected by phytoplasmas. With the aim of shedding light on the cell wall response to AP disease in the economically relevant fruit-tree Malus × domestica Borkh., we investigated the expression of the cellulose (CesA) and callose synthase (CalS) genes in different organs (i.e., leaves, roots and branch phloem) of healthy and infected symptomatic outdoor-grown trees, sampled over the course of two time points (i.e., spring and autumn 2011), as well as in in vitro micropropagated control and infected plantlets. A strong up-regulation in the expression of cell wall biosynthetic genes was recorded in roots from infected trees. Secondary cell wall CesAs showed up-regulation in the phloem tissue from branches of infected plants, while either a down-regulation of some genes or no major changes were observed in the leaves. Micropropagated plantlets also showed an increase in cell wall-related genes and constitute a useful system for a general assessment of gene expression analysis upon phytoplasma infection. Finally, we also report the presence of several ‘knot’-like structures along the roots of infected apple trees and discuss the occurrence of this interesting phenotype in relation to the gene expression results and the modalities of phytoplasma diffusion. PMID:23086810

  6. Fostering Self-Regulated Learning through Distance Education: A Case Study of M.Phil Secondary Teacher Education Program of Allama Iqbal Open University

    Science.gov (United States)

    Ambreen, Munazza; Haqdad, Ambreen; Saleem, Wajid A.

    2016-01-01

    Self-regulated learning (SLR) has been recognized as a pivotal antecedent of students' effective learning and academic achievement. A self-regulated learner can independently and effectively plan for learning, choose and use appropriate learning strategies and reflect and monitor learning progress. Self-regulated learning, for learners in general…

  7. DNA repair genes RAD52 and SRS2, a cell wall synthesis regulator gene SMI1, and the membrane sterol synthesis scaffold gene ERG28 are important in efficient Agrobacterium-mediated yeast transformation with chromosomal T-DNA.

    Science.gov (United States)

    Ohmine, Yuta; Satoh, Yukari; Kiyokawa, Kazuya; Yamamoto, Shinji; Moriguchi, Kazuki; Suzuki, Katsunori

    2016-04-02

    Plant pathogenic Agrobacterium strains can transfer T-DNA regions of their Ti plasmids to a broad range of eukaryotic hosts, including fungi, in vitro. In the recent decade, the yeast Saccharomyces cerevisiae is used as a model host to reveal important host proteins for the Agrobacterium-mediated transformation (AMT). Further investigation is required to understand the fundamental mechanism of AMT, including interaction at the cell surface, to expand the host range, and to develop new tools. In this study, we screened a yeast mutant library for low AMT mutant strains by advantage of a chromosome type T-DNA, which transfer is efficient and independent on integration into host chromosome. By the mutant screening, we identified four mutant strains (srs2Δ, rad52Δ, smi1Δ and erg28Δ), which showed considerably low AMT efficiency. Structural analysis of T-DNA product replicons in AMT colonies of mutants lacking each of the two DNA repair genes, SRS2 and RAD52, suggested that the genes act soon after T-DNA entry for modification of the chromosomal T-DNA to stably maintain them as linear replicons and to circularize certain T-DNA simultaneously. The cell wall synthesis regulator SMI1 might have a role in the cell surface interaction between the donor and recipient cells, but the smi1Δ mutant exhibited pleiotropic effect, i.e. low effector protein transport as well as low AMT for the chromosomal T-DNA, but relatively high AMT for integrative T-DNAs. The ergosterol synthesis regulator/enzyme-scaffold gene ERG28 probably contributes by sensing a congested environment, because growth of erg28Δ strain was unaffected by the presence of donor bacterial cells, while the growth of the wild-type and other mutant yeast strains was suppressed by their presence. RAD52 and the DNA helicase/anti-recombinase gene SRS2 are necessary to form and maintain artificial chromosomes through the AMT of chromosomal T-DNA. A sterol synthesis scaffold gene ERG28 is important in the high

  8. A Structurally Specialized Uniform Wall Layer is Essential for Constructing Wall Ingrowth Papillae in Transfer Cells

    Science.gov (United States)

    Xia, Xue; Zhang, Hui-Ming; Offler, Christina E.; Patrick, John W.

    2017-01-01

    Transfer cells are characterized by wall labyrinths with either a flange or reticulate architecture. A literature survey established that reticulate wall ingrowth papillae ubiquitously arise from a modified component of their wall labyrinth, termed the uniform wall layer; a structure absent from flange transfer cells. This finding sparked an investigation of the deposition characteristics and role of the uniform wall layer using a Vicia faba cotyledon culture system. On transfer of cotyledons to culture, their adaxial epidermal cells spontaneously trans-differentiate to a reticulate architecture comparable to their abaxial epidermal transfer cell counterparts formed in planta. Uniform wall layer construction commenced once adaxial epidermal cell expansion had ceased to overlay the original outer periclinal wall on its inner surface. In contrast to the dense ring-like lattice of cellulose microfibrils in the original primary wall, the uniform wall layer was characterized by a sparsely dispersed array of linear cellulose microfibrils. A re-modeled cortical microtubule array exerted no influence on uniform wall layer formation or on its cellulose microfibril organization. Surprisingly, formation of the uniform wall layer was not dependent upon depositing a cellulose scaffold. In contrast, uniform wall cellulose microfibrils were essential precursors for constructing wall ingrowth papillae. On converging to form wall ingrowth papillae, the cellulose microfibril diameters increased 3-fold. This event correlated with up-regulated differential, and transfer-cell specific, expression of VfCesA3B while transcript levels of other cellulose biosynthetic-related genes linked with primary wall construction were substantially down-regulated. PMID:29259611

  9. Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum.

    Directory of Open Access Journals (Sweden)

    Ruiqin Zhong

    Full Text Available Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs and a MYB (PvMYB46A, for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

  10. 壁材交联对相变微胶囊的性能调控%Performance regulation of phase change microcapsules by cross-linking of wall material

    Institute of Scientific and Technical Information of China (English)

    管羽; 张维; 刘金树

    2017-01-01

    In order to investigate the effect of wall material composition on the performance of phase change microcapsules,a mixture of solid and liquid paraffin is used as the core material and methyl methacrylate as the wall material to prepare phase change material microcapsules by suspension polymerization method.Pentaerythritol tetraacrylate and allyl methacrylate are crosslinked with methyl methacrylate to obtain phase change microcapsules with different wall materials,and then to achieve the regulation of microcapsule performance.The results of scanning electron microscopy (SEM) show that the addition of crosslinking agents can effectively improve the regularity and surface smoothness of phase change microcapsules,as well as the uniformity of particle size distribution.The results of thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) analysis show that the crosslinking agents can significantly reduce the mass loss rate of the microcapsules at high temperature,increase the decomposition temperature range,enhance the stability of the wall material and improve the coating efficiency of the wall material.Compared with the untreated microcapsules,the phase change enthalpy decreased.When adding 1.0 g pentaerythritol tetraacrylate,the obtained microcapsules have good dispersibility,regular spherical shap.e,smooth surface,particle size of 1.0~1.5 μm,good thermal stability,can withstand 155 ℃ high temperature,and the maximum enthalpy of phase change is 29.643 J/g.%为探讨壁材组成对相变微胶囊性能的调控作用,选用固液混合石蜡为芯材,甲基丙烯酸甲酯为壁材,利用悬浮聚合法制备相变材料微胶囊.加入季戊四醇四丙烯酸酯和甲基丙烯酸烯丙酯作为交联剂,与甲基丙烯酸甲酯进行交联共聚,得到不同壁材组成的相变微胶囊,进而实现对微胶囊性能的调控.扫描电镜(SEM)结果表明,交联剂的加入能够有效提高相变微胶囊的规整性和表

  11. [Secondary hypertension].

    Science.gov (United States)

    Yoshida, Yuichi; Shibata, Hirotaka

    2015-11-01

    Hypertension is a common disease and a crucial predisposing factor of cardiovascular diseases. Approximately 10% of hypertensive patients are secondary hypertension, a pathogenetic factor of which can be identified. Secondary hypertension consists of endocrine, renal, and other diseases. Primary aldosteronism, Cushing's syndrome, pheochromocytoma, hyperthyroidism, and hypothyroidism result in endocrine hypertension. Renal parenchymal hypertension and renovascular hypertension result in renal hypertension. Other diseases such as obstructive sleep apnea syndrome are also very prevalent in secondary hypertension. It is very crucial to find and treat secondary hypertension at earlier stages since most secondary hypertension is curable or can be dramatically improved by specific treatment. One should keep in mind that screening of secondary hypertension should be done at least once in a daily clinical practice.

  12. The development and structure of thick-walled, multicellular, aerial spores in Diheterospora chlamydosporia (=Verticillium chlamydosporium).

    Science.gov (United States)

    Cambell, W P; Griffiths, D A

    1975-07-01

    The aerial, thick-walled spores in Diheterospara chlamydosporia arose as terminal swellings on erect hyphae. Repeated septation of the continuously swelling spore resulted in a multicellular structure. Immediately after the onset of septation secondary wall material was laid down between the two-layered primary wall and the plasmalemma. The presence of secondary wall material indicates that the multicellular spore is a dictyochlamydospore and not an aleuriospore. The relationship between chlamydospores and aleuriospores in other fungi is discussed.

  13. Systems and synthetic biology approaches to alter plant cell walls and reduce biomass recalcitrance.

    Science.gov (United States)

    Kalluri, Udaya C; Yin, Hengfu; Yang, Xiaohan; Davison, Brian H

    2014-12-01

    Fine-tuning plant cell wall properties to render plant biomass more amenable to biofuel conversion is a colossal challenge. A deep knowledge of the biosynthesis and regulation of plant cell wall and a high-precision genome engineering toolset are the two essential pillars of efforts to alter plant cell walls and reduce biomass recalcitrance. The past decade has seen a meteoric rise in use of transcriptomics and high-resolution imaging methods resulting in fresh insights into composition, structure, formation and deconstruction of plant cell walls. Subsequent gene manipulation approaches, however, commonly include ubiquitous mis-expression of a single candidate gene in a host that carries an intact copy of the native gene. The challenges posed by pleiotropic and unintended changes resulting from such an approach are moving the field towards synthetic biology approaches. Synthetic biology builds on a systems biology knowledge base and leverages high-precision tools for high-throughput assembly of multigene constructs and pathways, precision genome editing and site-specific gene stacking, silencing and/or removal. Here, we summarize the recent breakthroughs in biosynthesis and remodelling of major secondary cell wall components, assess the impediments in obtaining a systems-level understanding and explore the potential opportunities in leveraging synthetic biology approaches to reduce biomass recalcitrance. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  14. Secondary Evaluations.

    Science.gov (United States)

    Cook, Thomas D.

    Secondary evaluations, in which an investigator takes a body of evaluation data collected by a primary evaluation researcher and examines the data to see if the original conclusions about the program correspond with his own, are discussed. The different kinds of secondary evaluations and the advantages and disadvantages of each are pointed out,…

  15. 40 CFR 260.43 - Legitimate recycling of hazardous secondary materials regulated under § 260.34, § 261.2(a)(2)(ii...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Legitimate recycling of hazardous... (CONTINUED) HAZARDOUS WASTE MANAGEMENT SYSTEM: GENERAL Rulemaking Petitions § 260.43 Legitimate recycling of... demonstrate that the recycling is legitimate. Hazardous secondary material that is not legitimately recycled...

  16. Neurofibromas as bilateral cystic chest wall swellings.

    African Journals Online (AJOL)

    secondary to an infection, usually parasitic infections. [6,7]. However, cystic tumours of the chest wall result- ing from degenerative changes in peripheral nerves of its layers are rare, and we did not see any in the pub- lished literature. We are reporting a single case of bilat- eral cystic degenerative changes in neurofibromas ...

  17. Reflections on a flat wall

    International Nuclear Information System (INIS)

    Stevenson, G.R.; Huhtinen, M.

    1995-01-01

    This paper describes an investigation into whether estimates of attenuation in the flat sidewalls of the tunnel for the MC main ring can be based on a simple point-source/line-of-sight model. Having seen the limitations of such a model, an alternative is proposed where the main radiation source is not the initial object struck by the beam but the plane source provided by the first interactions of secondaries from the target in the shield-wall. This is shown to have a closer relation to reality than the point-source/line-of-sight model. (author)

  18. The Role of Auxin in Cell Wall Expansion.

    Science.gov (United States)

    Majda, Mateusz; Robert, Stéphanie

    2018-03-22

    Plant cells are surrounded by cell walls, which are dynamic structures displaying a strictly regulated balance between rigidity and flexibility. Walls are fairly rigid to provide support and protection, but also extensible, to allow cell growth, which is triggered by a high intracellular turgor pressure. Wall properties regulate the differential growth of the cell, resulting in a diversity of cell sizes and shapes. The plant hormone auxin is well known to stimulate cell elongation via increasing wall extensibility. Auxin participates in the regulation of cell wall properties by inducing wall loosening. Here, we review what is known on cell wall property regulation by auxin. We focus particularly on the auxin role during cell expansion linked directly to cell wall modifications. We also analyze downstream targets of transcriptional auxin signaling, which are related to the cell wall and could be linked to acid growth and the action of wall-loosening proteins. All together, this update elucidates the connection between hormonal signaling and cell wall synthesis and deposition.

  19. Cell Wall Remodeling Enzymes Modulate Fungal Cell Wall Elasticity and Osmotic Stress Resistance.

    Science.gov (United States)

    Ene, Iuliana V; Walker, Louise A; Schiavone, Marion; Lee, Keunsook K; Martin-Yken, Hélène; Dague, Etienne; Gow, Neil A R; Munro, Carol A; Brown, Alistair J P

    2015-07-28

    a network of cell wall polysaccharides, which are remodeled in response to growth conditions and environmental stress. However, little is known about how cell wall elasticity is regulated and how it affects adaptation to stresses such as sudden changes in osmolarity. We show that elasticity is critical for survival under conditions of osmotic shock, before stress signaling pathways have time to induce gene expression and drive glycerol accumulation. Critical cell wall remodeling enzymes control cell wall flexibility, and its regulation is strongly dependent on host nutritional inputs. We also demonstrate an entirely new level of cell wall dynamism, where significant architectural changes and structural realignment occur within seconds of an osmotic shock. Copyright © 2015 Ene et al.

  20. Hemicellulose biosynthesis and degradation in tobacco cell walls

    NARCIS (Netherlands)

    Compier, M.G.M.

    2005-01-01

    Natural fibres have a wide range of technological applications, such as in paper and textile industries. The basic properties and the quality of plant fibres are determined by the composition of the plant cell wall. Characteristic for fibres are thick secondary cell walls, which consist of cellulose

  1. Characterising the cellulose synthase complexes of cell walls

    NARCIS (Netherlands)

    Mansoori Zangir, N.

    2012-01-01

    One of the characteristics of the plant kingdom is the presence of a structural cell wall. Cellulose is a major component in both the primary and secondary cell walls of plants. In higher plants cellulose is synthesized by so called rosette protein complexes with cellulose synthases (CESAs) as

  2. DESIK final report. Energy wise design and regulation of the secondary side of indirect cooling systems with natural coolants; DESIK slutrapportering. Energirigtig design og regulering af sekundaersiden pae indirekte koeleanlaeg med naturlige koelemidler

    Energy Technology Data Exchange (ETDEWEB)

    Jakobsen, Arne

    2006-02-15

    The project's aim was to produce knowledge and tools to facilitate the process of implementing energy efficient secondary cooling systems, or merely to avoid overconsumption of energy on account of insufficient relevant professional background. The project has been communicated as a PC tool, which can be ordered from aj(commercial at)ipu.dk. Project focus has been on some general aspects of secondary systems as well as two scopes of application: supermarket cooling systems and air conditioning of office buildings. (BA)

  3. Secondary Headaches

    Science.gov (United States)

    ... in the medical history or examination to suggest secondary headache. Headache can be caused by general medical conditions such as severe hypertension, or by conditions that affect the brain and ...

  4. Abdominal wall fat pad biopsy

    Science.gov (United States)

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... is the most common method of taking an abdominal wall fat pad biopsy . The health care provider cleans the ...

  5. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  6. Roles of membrane trafficking in plant cell wall dynamics

    Directory of Open Access Journals (Sweden)

    Kazuo eEbine

    2015-10-01

    Full Text Available The cell wall is one of the characteristic components of plant cells. The cell wall composition differs among cell types and is modified in response to various environmental conditions. To properly generate and modify the cell wall, many proteins are transported to the plasma membrane or extracellular space through membrane trafficking, which is one of the key protein transport mechanisms in eukaryotic cells. Given the diverse composition and functions of the cell wall in plants, the transport of the cell wall components and proteins that are involved in cell wall-related events could be specialized for each cell type, i.e., the machinery for cell wall biogenesis, modification, and maintenance could be transported via different trafficking pathways. In this review, we summarize the recent progress in the current understanding of the roles and mechanisms of membrane trafficking in plant cells and focus on the biogenesis and regulation of the cell wall.

  7. Secondary Containment Design for the LLNL B801 Diala Oil Tank

    Energy Technology Data Exchange (ETDEWEB)

    Mertesdorf, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-14

    Design is to add an extension to the secondary containment of tank T1-A3 at building 801. Piping from the inner tank penetrates the secondary containment tank below the liquid level of the primary tank. To meet Oil Pollution Prevention Regulation 40 CFR 120.7 the single wall piping needs to be provided with secondary containment. Steel Tank Institute (STI) conference publication states: §112.3(d)(1)(iii) –SPCC Plan requirements- Systems shall be designed in accordance with good engineering practice, including consideration of applicable industry standards and that procedures for required inspections and testing have been established. Section 112.7(a)(2) allows for deviations from specific rule requirements, provided the Owner/operator responsible to select, document and implement alternate measure and a PE certifies the SPCC Plan in accordance with good engineering practices, including consideration of industry standards

  8. Implications of secondary structure prediction and amino acid sequence comparison of class I and class II phosphoribosyl diphosphate synthases on catalysis, regulation, and quaternary structure

    DEFF Research Database (Denmark)

    Krath, B N; Hove-Jensen, B

    2001-01-01

    Spinach 5-phospho-D-ribosyl alpha-1-diphosphate (PRPP) synthase isozyme 4 was synthesized in Escherichia coli and purified to near homogeneity. The activity of the enzyme is independent of P(i); it is inhibited by ADP in a competitive manner, indicating a lack of an allosteric site; and it accepts...... is consistent with a homotrimer. Secondary structure prediction shows that spinach PRPP synthase isozyme 4 has a general folding similar to that of Bacillus subtilis class I PRPP synthase, for which the three-dimensional structure has been solved, as the position and extent of helices and beta-sheets of the two...... in the spinach enzyme. In contrast, residues of the active site of B. subtilis PRPP synthase show extensive conservation in spinach PRPP synthase isozyme 4....

  9. Thyroid hormone receptor-β1 signaling is critically involved in regulating secondary ossification via promoting transcription of the Ihh gene in the epiphysis.

    Science.gov (United States)

    Xing, Weirong; Aghajanian, Patrick; Goodluck, Helen; Kesavan, Chandrasekhar; Cheng, Shaohong; Pourteymoor, Sheila; Watt, Heather; Alarcon, Catrina; Mohan, Subburaman

    2016-05-15

    Thyroid hormone (TH) action is mediated through two nuclear TH receptors, THRα and THRβ. Although the role of THRα is well established in bone, less is known about the relevance of THRβ-mediated signaling in bone development. On ther basis of our recent finding that TH signaling is essential for initiation and formation of secondary ossification center, we evaluated the role of THRs in mediating TH effects on epiphysial bone formation. Two-day treatment of TH-deficient Tshr(-/-) mice with TH increased THRβ1 mRNA level 3.4-fold at day 7 but had no effect on THRα1 mRNA level at the proximal tibia epiphysis. Treatment of serum-free cultures of tibias from 3-day-old mice with T3 increased THRβ1 expression 2.1- and 13-fold, respectively, at 24 and 72 h. Ten-day treatment of Tshr(-/-) newborns (days 5-14) with THRβ1 agonist GC1 at 0.2 or 2.0 μg/day increased BV/TV at day 21 by 225 and 263%, respectively, compared with vehicle treatment. Two-day treatment with GC1 (0.2 μg/day) increased expression levels of Indian hedgehog (Ihh) 100-fold, osterix 15-fold, and osteocalcin 59-fold compared with vehicle at day 7 in the proximal tibia epiphysis. Gel mobility shift assay demonstrated that a putative TH response element in the distal promoter of mouse Ihh gene interacted with THRβ1. GC1 treatment (1 nM) increased Ihh distal promoter activity 20-fold after 48 h in chondroctyes. Our data suggest a novel role for THRβ1 in secondary ossification at the epiphysis that involves transcriptional upregulation of Ihh gene.

  10. Secondary middle turbinate: case report

    Energy Technology Data Exchange (ETDEWEB)

    Aburjeli, Bruna de Oliveira Melim; Avila, Ana Flavia Assis de; Diniz, Renata Lopes Furletti Caldeira; Motta, Emilia Guerra Pinto Coelho; Ribeiro, Marcelo Almeida; Moreira, Wanderval, E-mail: bruninha86@hotmail.com [Radiology and Imaging Diagnosis, Hospital Mater Dei, Belo Horizonte, MG (Brazil)

    2012-11-15

    Secondary middle turbinate is an anatomical variant rarely observed in the nasal cavity, firstly described by Khanobthamchai et al. as a bone structure originating from the lateral nasal wall and covered by soft tissue. In most cases reported in the literature, this variant is bilateral, occurring without associated complications. In the present report, the authors describe the case of patient of their institution with such anatomical variation. (author)

  11. Secondary middle turbinate: case report

    International Nuclear Information System (INIS)

    Aburjeli, Bruna de Oliveira Melim; Avila, Ana Flavia Assis de; Diniz, Renata Lopes Furletti Caldeira; Motta, Emilia Guerra Pinto Coelho; Ribeiro, Marcelo Almeida; Moreira, Wanderval

    2012-01-01

    Secondary middle turbinate is an anatomical variant rarely observed in the nasal cavity, firstly described by Khanobthamchai et al. as a bone structure originating from the lateral nasal wall and covered by soft tissue. In most cases reported in the literature, this variant is bilateral, occurring without associated complications. In the present report, the authors describe the case of patient of their institution with such anatomical variation. (author)

  12. 40 CFR 133.102 - Secondary treatment.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Secondary treatment. 133.102 Section... TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs describe the minimum level of effluent quality attainable by secondary treatment in terms of the parameters—BOD5, SS and pH. All...

  13. The AreA transcription factor in Fusarium graminearum regulates the use of some nonpreferred nitrogen sources and secondary metabolite production

    DEFF Research Database (Denmark)

    Giese, Nanna Henriette; Sondergaard, Teis Esben; Sorensen, Jens Laurids

    2013-01-01

    and asparagine was found to be a preferential nitrogen source for F. graminearum. Deletion of areA led to poor growth on NaNO3 suggesting its involvement in regulation of the nitrate reduction process. In addition utilization of aspartic acid, histidine, isoleucine, leucine, threonine, tyrosine, and valine...... as nitrogen sources was shown to depend of a functional AreA. AreA was shown to be required for the production of the mycotoxins deoxynivalenol (DON), zearalenone, and fusarielin H regardless of the nutrient medium. Deletion of nmr, the repressor of AreA under nitrogen sufficient conditions, had little effect...

  14. Wall Finishes; Carpentry: 901895.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course outline is designed to provide instruction in selecting, preparing, and installing wall finishing materials. Prerequisites for the course include mastery of building construction plans, foundations and walls, and basic mathematics. Intended for use in grades 11 and 12, the course contains five blocks of study totaling 135 hours of…

  15. Wall Construction; Carpentry: 901892.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The curriculum guide outlines a course designed to provide instruction in floor and wall layout, and in the diverse methods and construction of walls. Upon completion of this course the students should have acquired a knowledge of construction plans and structural foundations in addition to a basic knowledge of mathematics. The course consists of…

  16. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, Lineke

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful,

  17. Supersymmetric domain walls

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Kleinschmidt, Axel; Riccioni, Fabio

    2012-01-01

    We classify the half-supersymmetric "domain walls," i.e., branes of codimension one, in toroidally compactified IIA/IIB string theory and show to which gauged supergravity theory each of these domain walls belong. We use as input the requirement of supersymmetric Wess-Zumino terms, the properties of

  18. Seismic behavior of semi-supported steel shear walls

    DEFF Research Database (Denmark)

    Jahanpour, A.; Jönsson, J.; Moharrami, H.

    2012-01-01

    During the recent past decade semi-supported steel shear walls (SSSW) have been introduced as an alternative to the traditional type of steel plate shear walls. In this system the shear wall does not connect directly to the main columns of the building frame; instead it is connected to a pair...... of secondary columns that do not carry vertical gravity loads. In this paper, the interaction between the wall plate and the surrounding frame is investigated experimentally for typical SSSW systems in which the wall-frame has a bending-dominant behavior. Based on the possible storey failure mechanisms...... a simple method is proposed for design of the floor beams. A quasi static cyclic experimental study has been performed in order to investigate the collapse behavior of the wall-plate and surrounding frame. Furthermore the test setup has been developed in order to facilitate standardized cyclic tests...

  19. Parathyroid hormone contributes to the down-regulation of cytochrome P450 3A through the cAMP/PI3K/PKC/PKA/NF-κB signaling pathway in secondary hyperparathyroidism.

    Science.gov (United States)

    Watanabe, Hiroshi; Sugimoto, Ryusei; Ikegami, Komei; Enoki, Yuki; Imafuku, Tadashi; Fujimura, Rui; Bi, Jing; Nishida, Kento; Sakaguchi, Yoshiaki; Murata, Michiya; Maeda, Hitoshi; Hirata, Kenshiro; Jingami, Sachiko; Ishima, Yu; Tanaka, Motoko; Matsushita, Kazutaka; Komaba, Hirotaka; Fukagawa, Masafumi; Otagiri, Masaki; Maruyama, Toru

    2017-12-01

    Chronic kidney disease (CKD), which affects, not only renal clearance, but also non-renal clearance, is accompanied by a decline in renal function. Although it has been suggested that humoral factors, such as uremic toxins that accumulate in the body under CKD conditions, could be involved in the changes associated with non-renal drug clearance, the overall process is not completely understood. In this study, we report on the role of parathyroid hormone (PTH), a middle molecule uremic toxin, on the expression of drug metabolizing or transporting proteins using rats with secondary hyperparathyroidism (SHPT) as models. In SHPT rats, hepatic and intestinal CYP3A expression was suppressed, but the changes were recovered by the administration of the calcimimetic cinacalcet, a PTH suppressor. Under the same experimental conditions, a pharmacokinetic study using orally administered midazolam, a substrate for CYP3A, showed that the AUC was increased by 5 times in SHPT rats, but that was partially recovered by a cinacalcet treatment. This was directly tested in rat primary hepatocytes and intestinal Caco-2 cells where the expression of the CYP3A protein was down-regulated by PTH (1-34). In Caco-2 cells, PTH (1-34) down-regulated the expression of CYP3A mRNA, but an inactive PTH derivative (13-34) had no effect. 8-Bromo-cyclic adenosine monophosphate, a membrane-permeable cAMP analog, reduced mRNA expression of CYP3A whereas the inhibitors of PI3K, NF-κB, PKC and PKA reversed the PTH-induced CYP3A down-regulation. These results suggest that PTH down-regulates CYP3A through multiple signaling pathways, including the PI3K/PKC/PKA/NF-κB pathway after the elevation of intracellular cAMP, and the effect of PTH can be prevented by cinacalcet treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. The Cek1‑mediated MAP kinase pathway regulates exposure of α‑1,2 and β‑1,2‑mannosides in the cell wall of Candida albicans modulating immune recognition.

    Science.gov (United States)

    Román, E; Correia, I; Salazin, A; Fradin, C; Jouault, T; Poulain, D; Liu, F-T; Pla, J

    2016-07-03

    The Cek1 MAP kinase (MAPK) mediates vegetative growth and cell wall biogenesis in the fungal pathogen Candida albicans. Alterations in the fungal cell wall caused by a defective Cek1‑mediated signaling pathway leads to increased β‑1,3‑glucan exposure influencing dectin‑1 fungal recognition by immune cells. We show here that cek1 cells also display an increased exposure of α‑1,2 and β‑1,2‑mannosides (α‑M and β‑M), a phenotype shared by strains defective in the activating MAPKK Hst7, suggesting a general defect in cell wall assembly. cek1 cells display walls with loosely bound material as revealed by transmission electron microscopy and are sensitive to tunicamycin, an inhibitor of N‑glycosylation. Transcriptomal analysis of tunicamycin treated cells revealed a differential pattern between cek1 and wild type cells which involved mainly cell wall and stress related genes. Mapping α‑M and β‑M epitopes in the mannoproteins of different cell wall fractions (CWMP) revealed an important shift in the molecular weight of the mannan derived from mutants defective in this MAPK pathway. We have also assessed the role of galectin‑3, a member of a β‑galactoside‑binding protein family shown to bind to and kill C. albicans through β‑M recognition, in the infection caused by cek1 mutants. Increased binding of cek1 to murine macrophages was shown to be partially blocked by lactose. Galectin-3(-/-) mice showed increased resistance to fungal infection, although galectin-3 did not account for the reduced virulence of cek1 mutants in a mouse model of systemic infection. All these data support a role for the Cek1‑mediated pathway in fungal cell wall maintenance, virulence and antifungal discovery.

  1. Two endogenous proteins that induce cell wall extension in plants

    Science.gov (United States)

    McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

    1992-01-01

    Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

  2. Bibliography on plasma-wall interactions

    International Nuclear Information System (INIS)

    Okano, J.

    1980-05-01

    Bibliography is compiled for the following subjects: (1) Plasma-wall interactions, general, (2) Sputtering, (3) Chemical sputtering, (4) Blistering, (5) Electron-impact desorption, (6) Thermal desorption and photo-desorption, (7) Emission of secondary electrons and ions, emission of photoelectrons, and material for getters, (8) Gas release and trapping, (9) Approach from surface diagnostics (review). The compilation has not been intended to be complete, but to give a first step toward a further study of the respective subjects. (author)

  3. Solar Walls in tsbi3

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne

    tsbi3 is a user-friendly and flexible computer program, which provides support to the design team in the analysis of the indoor climate and the energy performance of buildings. The solar wall module gives tsbi3 the capability of simulating solar walls and their interaction with the building....... This version, C, of tsbi3 is capable of simulating five types of solar walls say: mass-walls, Trombe-walls, double Trombe-walls, internally ventilated walls and solar walls for preheating ventilation air. The user's guide gives a description of the capabilities and how to simulate solar walls in tsbi3....

  4. The dorsal shell wall structure of Mesozoic ammonoids

    Directory of Open Access Journals (Sweden)

    Gregor Radtke

    2017-03-01

    Full Text Available The study of pristine preserved shells of Mesozoic Ammonoidea shows different types of construction and formation of the dorsal shell wall. We observe three major types: (i The vast majority of Ammonoidea, usually planispirally coiled, has a prismatic reduced dorsal shell wall which consists of an outer organic component (e.g., wrinkle layer, which is the first layer to be formed, and the subsequently formed dorsal inner prismatic layer. The dorsal mantle tissue suppresses the formation of the outer prismatic layer and nacreous layer. With the exception of the outer organic component, secretion of a shell wall is omitted at the aperture. A prismatic reduced dorsal shell wall is always secreted immediately after the hatching during early teleoconch formation. Due to its broad distribution in (planispiral Ammonoidea, the prismatic reduced dorsal shell wall is probably the general state. (ii Some planispirally coiled Ammonoidea have a nacreous reduced dorsal shell wall which consists of three mineralized layers: two prismatic layers (primary and secondary dorsal inner prismatic layer and an enclosed nacreous layer (secondary dorsal nacreous layer. The dorsal shell wall is omitted at the aperture and was secreted in the rear living chamber. Its layers are a continuation of an umbilical shell doubling (reinforcement by additional shell layers that extends towards the ventral crest of the preceding whorl. The nacreous reduced dorsal shell wall is formed in the process of ontogeny following a prismatic reduced dorsal shell wall. (iii Heteromorph and some planispirally coiled taxa secrete a complete dorsal shell wall which forms a continuation of the ventral and lateral shell layers. It is formed during ontogeny following a prismatic reduced dorsal shell wall or a priori. The construction is identical with the ventral and lateral shell wall, including a dorsal nacreous layer. The wide distribution of the ability to form dorsal nacre indicates that it is

  5. Vestured pits: a diagnostic character in the secondary xylem of Myrtales

    NARCIS (Netherlands)

    Jansen, S.; Pletsers, A.; Rabaey, D.; Lens, F.

    2008-01-01

    Vestures are small projections from the secondary cell wall associated with tracheary elements of the secondary xylem. They are usually associated with bordered pits and characterize various angiosperm families, including important timber species such as Dipterocarpaceae and Eucalyptus trees. The

  6. Secondary osteoporosis.

    Science.gov (United States)

    Gennari, C; Martini, G; Nuti, R

    1998-06-01

    Generalized osteoporosis currently represents a heterogeneous group of conditions with many different causes and pathogenetic mechanisms, that often are variably associated. The term "secondary" is applied to all patients with osteoporosis in whom the identifiable causal factors are other than menopause and aging. In this heterogeneous group of conditions, produced by many different pathogenetic mechanisms, a negative bone balance may be variably associated with low, normal or increased bone remodeling states. A consistent group of secondary osteoporosis is related to endocrinological or iatrogenic causes. Exogenous hypercortisolism may be considered an important risk factor for secondary osteoporosis in the community, and probably glucocorticoid-induced osteoporosis is the most common type of secondary osteoporosis. Supraphysiological doses of corticosteroids cause two abnormalities in bone metabolism: a relative increase in bone resorption, and a relative reduction in bone formation. Bone loss, mostly of trabecular bone, with its resultant fractures is the most incapacitating consequence of osteoporosis. The estimated incidence of fractures in patients prescribed corticosteroid is 30% to 50%. Osteoporosis is considered one of the potentially serious side effects of heparin therapy. The occurrence of heparin-induced osteoporosis appeared to be strictly related to the length of treatment (over 4-5 months), and the dosage (15,000 U or more daily), but the pathogenesis is poorly understood. It has been suggested that heparin could cause an increase in bone resorption by increasing the number of differentiated osteoclasts, and by enhancing the activity of individual osteoclasts. Hyperthyroidism is frequently associated with loss of trabecular and cortical bone; the enhanced bone turnover that develops in thyrotoxicosis is characterized by an increase in the number of osteoclasts and resorption sites, and an increase in the ratio of resorptive to formative bone

  7. Secondary osteoporosis.

    Science.gov (United States)

    Boyle, I T

    1993-10-01

    Osteoporosis with attendant increased fracture risk is a common complication of many other diseases. Indeed, almost all chronic diseases make some impact on life-style, usually by restricting physical activity and hence reducing the anabolic effect of exercise and gravitational strains on the skeleton. Restricted appetite and modified gastrointestinal tract function is another commonplace finding that has an impact on bone nutrition and synthesis, as on other systems. Sex hormone status is of particular importance for the maintenance of the normal skeleton, and the postmenopausal woman is at particular risk for most causes of secondary osteoporosis. In dealing with secondary osteoporosis in the hypo-oestrogenic woman, the question of giving hormone replacement therapy in addition to other disease-specific therapy should always be considered, as, for example, in a young amenorrhoeic woman with Crohn's disease. Similarly, in hypogonadal men the administration of testosterone is useful for bone conservation. The wider availability of bone densitometry ought to make us more aware of the presence of osteoporosis in the many disease states discussed above. This is particularly important as the life span of such patients is now increased by improved management of the underlying disease process in many instances. Even in steroid-induced osteoporosis--one of the commonest and most severe forms of osteoporosis--we now have some effective therapy in the form of the bisphosphonates and other anti-bone-resorbing drug classes. The possibility of prophylaxis against secondary osteoporosis has therefore become a possibility, although the very long-term effects of such drug regimens are still unknown. In some situations, such as thyrotoxicosis, Cushing's syndrome and immobilization, spontaneous resolution of at least part of the osteoporosis is possible after cure of the underlying problem. The shorter the existence of the basic problem, the more successful the restoration of the

  8. Stability of spiral welded tubes in Quay Walls

    NARCIS (Netherlands)

    Gresnigt, A.M.; van Es, S.H.J.

    2013-01-01

    A European research project (RFCS) has started to provide economic and safe guidance for the design of spirally welded tubes in combined walls. The main motivation for this project called COMBITUBE is that the current Eurocode 3 regulations for tubes in quay walls lead to uneconomic designs, because

  9. Plasma-wall interactions

    International Nuclear Information System (INIS)

    Behrisch, Rainer

    1978-01-01

    The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

  10. PpNAC1, a main regulator of phenylalanine biosynthesis and utilization in maritime pine.

    Science.gov (United States)

    Pascual, María Belén; Llebrés, María-Teresa; Craven-Bartle, Blanca; Cañas, Rafael A; Cánovas, Francisco M; Ávila, Concepción

    2018-05-01

    The transcriptional regulation of phenylalanine metabolism is particularly important in conifers, long-lived species that use large amounts of carbon in wood. Here, we show that the Pinus pinaster transcription factor, PpNAC1, is a main regulator of phenylalanine biosynthesis and utilization. A phylogenetic analysis classified PpNAC1 in the NST proteins group and was selected for functional characterization. PpNAC1 is predominantly expressed in the secondary xylem and compression wood of adult trees. Silencing of PpNAC1 in P. pinaster results in the alteration of stem vascular radial patterning and the down-regulation of several genes associated with cell wall biogenesis and secondary metabolism. Furthermore, transactivation and EMSA analyses showed that PpNAC1 is able to activate its own expression and PpMyb4 promoter, while PpMyb4 is able to activate PpMyb8, a transcriptional regulator of phenylalanine and lignin biosynthesis in maritime pine. Together, these results suggest that PpNAC1 is a functional ortholog of the ArabidopsisSND1 and NST1 genes and support the idea that key regulators governing secondary cell wall formation could be conserved between gymnosperms and angiosperms. Understanding the molecular switches controlling wood formation is of paramount importance for fundamental tree biology and paves the way for applications in conifer biotechnology. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Co-Occurrence of Regulated, Masked and Emerging Mycotoxins and Secondary Metabolites in Finished Feed and Maize—An Extensive Survey

    Directory of Open Access Journals (Sweden)

    Paula Kovalsky

    2016-12-01

    Full Text Available Global trade of agricultural commodities (e.g., animal feed requires monitoring for fungal toxins. Also, little is known about masked and emerging toxins and metabolites. 1926 samples from 52 countries were analysed for toxins and metabolites. Of 162 compounds detected, up to 68 metabolites were found in a single sample. A subset of 1113 finished feed, maize and maize silage samples containing 57 compounds from 2012 to 2015 from 44 countries was investigated using liquid chromatography and mass spectrometry. Deoxynivalenol (DON, zearalenone (ZEN and fumonisins showed large increases of annual medians in Europe. Within a region, distinct trends were observed, suggesting importance of local meteorology and cultivars. In 2015, median DON concentrations increased to 1400 μ g·kg − 1 in Austria, but were stable in Germany at 350 μ g·kg − 1 . In 2014, enniatins occurred at median concentrations of 250 μ g·kg − 1 in Europe, at levels similar to DON and ZEN. The latter were frequently correlated with DON-3-glucoside and ZEN-14-sulfate. Co-occurrence of regulated toxins was frequent with e.g., enniatins, and moniliformin. Correlation was observed between DON and DON-3-glucoside and with beauvericin. Results indicate that considerably more than 25% of agricultural commodities could be contaminated with mycotoxins as suggested by FAO, although this is at least partly due to the lower limits of detection in the current survey. Observed contamination percentages ranged from 7.1 to 79% for B trichothecenes and 88% for ZEN.

  12. Managing Vandalism in Day Secondary Schools in Zimbabwe ...

    African Journals Online (AJOL)

    Zimbabwe Journal of Educational Research ... contributing factors as leads to management strategies to reduce vandalism in day secondary schools. ... window panes, door handles, classroom furniture and writing on toilet walls and furniture.

  13. Identification of Novel Cell Wall Components

    Energy Technology Data Exchange (ETDEWEB)

    Michelle Momany

    2009-10-26

    Our DOE Biosciences-funded work focused on the fungal cell wall and morphogenesis. We are especially interested in how new cell wall material is targeted to appropriate areas for polar (asymmetric) growth. Polar growth is the only way that filamentous fungi explore the environment to find suitable substrates to degrade. Work funded by this grant has resulted in a total of twenty peer-reviewed publications. In work funded by this grant, we identified nine Aspergillus nidulans temperature-sensitive (ts) mutants that fail to send out a germ tube and show a swollen cell phenotype at restrictive temperature, the swo mutants. In other organisms, a swollen cell phenotype is often associated with misdirected growth or weakened cell walls. Our work shows that several of the A. nidulans swo mutants have defects in the establishment and maintenance of polarity. Cloning of several swo genes by complementation also showed that secondary modification of proteins seems is important in polarity. We also investigated cell wall biosynthesis and branching based on leads in literature from other organisms and found that branching and nuclear division are tied and that the cell wall reorganizes during development. In our most recent work we have focused on gene expression during the shift from isotropic to polar growth. Surprisingly we found that genes previously thought to be involved only in spore formation are important in early vegetative growth as well.

  14. Advanced walling systems

    CSIR Research Space (South Africa)

    De Villiers, A

    2010-01-01

    Full Text Available The question addressed by this chapter is: How should advanced walling systems be planned, designed, built, refurbished, and end their useful lives, to classify as smart, sustainable, green or eco-building environments?...

  15. Fusion: first wall problems

    International Nuclear Information System (INIS)

    Behrisch, R.

    1976-01-01

    Some of the relevant elementary atomic processes which are expected to be of significance to the first wall of a fusion reactor are reviewed. Up to the present, most investigations have been performed at relatively high ion energies, typically E greater than 5 keV, and even in this range the available data are very poor. If the plasma wall interaction takes place at energies of E greater than 1 keV the impurity introduction and first wall erosion which will take place predominantly by sputtering, will be large and may severely limit the burning time of the plasma. The wall bombardment and surface erosion will presumably not decrease substantially by introducing a divertor. The erosion can only be kept low if the energy of the bombarding ions and neutrals can be kept below the threshold for sputtering of 1 to 10 eV. 93 refs

  16. The toughness of secondary cell wall and woody tissue

    OpenAIRE

    Lucas, P. W.; Tan, H. T. W.; Cheng, P. Y.

    1997-01-01

    The 'across grain' toughness of 51 woods has been determined on thin wet sections using scissors. The moisture content of sections and the varying sharpness of the scissor blades had little effect on the results. In thin sections (less than 0.6mm), toughness rose linearly with section thickness. The intercept toughness at zero thickness, estimated from regression analysis, was proportional to relative density, consistent with values reported for non-woody plant tissues. Extrapolation of the i...

  17. Plasma-wall interaction

    International Nuclear Information System (INIS)

    Reichle, R.

    2004-01-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER

  18. Dynamic wall demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    Nakatsui, L.; Mayhew, W.

    1990-12-01

    The dynamic wall concept is a ventilation strategy that can be applied to a single family dwelling. With suitable construction, outside air can be admitted through the exterior walls of the house to the interior space to function as ventilation air. The construction and performance monitoring of a demonstration house built to test the dynamic wall concept in Sherwood Park, Alberta, is described. The project had the objectives of demonstrating and assessing the construction methods; determining the cost-effectiveness of the concept in Alberta; analyzing the operation of the dynamic wall system; and determining how other components and systems in the house interact with the dynamic wall. The exterior wall construction consisted of vinyl siding, spun-bonded polyolefin-backed (SBPO) rigid fiberglass sheathing, 38 mm by 89 mm framing, fiberglass batt insulation and 12.7 mm drywall. The mechanical system was designed to operate in the dynamic (negative pressure) mode, however flexibility was provided to allow operation in the static (balanced pressure) mode to permit monitoring of the walls as if they were in a conventional house. The house was monitored by an extensive computerized monitoring system. Dynamic wall operation was dependent on pressure and temperature differentials between indoor and outdoor as well as wind speed and direction. The degree of heat gain was found to be ca 74% of the indoor-outdoor temperature differential. Temperature of incoming dynamic air was significantly affected by solar radiation and measurement of indoor air pollutants found no significant levels. 4 refs., 34 figs., 11 tabs.

  19. Orbital wall fractures

    International Nuclear Information System (INIS)

    Iinuma, Toshitaka; Ishio, Ken-ichirou; Yoshinami, Hiroyoshi; Kuriyama, Jun-ichi; Hirota, Yoshiharu.

    1993-01-01

    A total of 59 cases of mild facial fractures (simple orbital wall fractures, 34 cases, other facial fractures, 25 cases) with the clinical suspects of orbital wall fractures were evaluated both by conventional views (Waters' and Caldwell views) and coronal CT scans. Conventional views were obtained, as an average, after 4 days and CT after 7 days of injuries. Both the medial wall and the floor were evaluated at two sites, i.e., anterior and posterior. The ethmoid-maxillary plate was also included in the study. The degree of fractures was classified as, no fractures, fractures of discontinuity, dislocation and fragmentation. The coronal CT images in bone window condition was used as reference and the findings were compared between conventional views and CT. The correct diagnosis was obtained as follows: orbital floor (anterior, 78%, posterior, 73%), medial orbital wall (anterior, 72%, posterior, 72%) and ethmoid-maxillary plate (64%). The false positive diagnosis was as follows: orbital floor (anterior only, 13%), medial orbital wall (anterior only, 7%) and ethmoid-maxillary plate (11%). The false negative diagnosis was as follows: orbital floor (anterior, 9%, posterior, 10%), medial orbital wall (anterior, 21%, posterior, 28%) and ethmoid-maxillary plate (21%). The results were compared with those of others in the past. (author)

  20. Characteristic thickened cell walls of the bracts of the 'eternal flower' Helichrysum bracteatum.

    Science.gov (United States)

    Nishikawa, Kuniko; Ito, Hiroaki; Awano, Tatsuya; Hosokawa, Munetaka; Yazawa, Susumu

    2008-07-01

    Helichrysum bracteatum is called an 'eternal flower' and has large, coloured, scarious bracts. These maintain their aesthetic value without wilting or discoloration for many years. There have been no research studies of cell death or cell morphology of the scarious bract, and hence the aim of this work was to elucidate these characteristics for the bract of H. bracteatum. DAPI (4'6-diamidino-2-phenylindol dihydrochloride) staining and fluorescence microscopy were used for observation of cell nuclei. Light microscopy (LM), transmission electron microscopy (TEM) and polarized light microscopy were used for observation of cells, including cell wall morphology. Cell death occurred at the bract tip during the early stage of flower development. The cell wall was the most prominent characteristic of H. bracteatum bract cells. Characteristic thickened secondary cell walls on the inside of the primary cell walls were observed in both epidermal and inner cells. In addition, the walls of all cells exhibited birefringence. Characteristic thickened secondary cell walls have orientated cellulose microfibrils as well as general secondary cell walls of the tracheary elements. For comparison, these characters were not observed in the petal and bract tissues of Chrysanthemum morifolium. Bracts at anthesis are composed of dead cells. Helichrysum bracteatum bracts have characteristic thickened secondary cell walls that have not been observed in the parenchyma of any other flowers or leaves. The cells of the H. bracteatum bract differ from other tissues with secondary cell walls, suggesting that they may be a new cell type.

  1. Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Bartley, Laura [Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology; Wu, Y. [Oklahoma State Univ., Stillwater, OK (United States); Zhu, L. [Oklahoma State Univ., Stillwater, OK (United States); Brummer, E. C. [Noble Foundation, Ardmore, OK (United States); Saha, M. [Noble Foundation, Ardmore, OK (United States)

    2016-05-31

    Inefficient conversion of biomass to biofuels is one of the main barriers for biofuel production from such materials. Approximately half of polysaccharides in biomass remain unused by typical biochemical conversion methods. Conversion efficiency is influenced by the composition and structure of cell walls of biomass. Grasses such as wheat, maize, and rice, as well as dedicated perennial bioenergy crops, like switchgrass, make up ~55% of biomass that can be produced in the United States. Grass cell walls have a different composition and patterning compared with dicotyledonous plants, including the well-studied model plant, Arabidopsis. This project identified genetic determinants of cell wall composition in grasses using both naturally occurring genetic variation of switchgrass and gene network reconstruction and functional assays in rice. In addition, the project linked functional data in rice and other species to switchgrass improvement efforts through curation of the most abundant class of regulators in the switchgrass genome. Characterizing natural diversity of switchgrass for variation in cell wall composition and properties, also known as quality, provides an unbiased avenue for identifying biologically viable diversity in switchgrass cell walls. To characterizing natural diversity, this project generated cell wall composition and enzymatic deconstruction data for ~450 genotypes of the Switchgrass Southern Association Collection (SSAC), a diverse collection composed of 36 switchgrass accessions from the southern U.S. distribution of switchgrass. Comparing these data with other measures of cell wall quality for the same samples demonstrated the complementary nature of the diverse characterization platforms now being used for biomass characterization. Association of the composition data with ~3.2K single nucleotide variant markers identified six significant single nucleotide variant markers co-associated with digestibility and another compositional trait. These

  2. Comprehensive Study of Plasma-Wall Sheath Transport Phenomena

    Science.gov (United States)

    2016-10-26

    the floating potential of wall material samples immersed in a low-temperature plasma were studied. Hysteresis is found to be due to secondary electron...continued research into plasma sheath physics. Hysteresis effects observed in the floating potential of wall material samples immersed in a low... Journal of Applied Physics, Volume 119, March 2016, pp. 113305 1-5. DISTRIBUTION A: Distribution approved for public release. 8 Figure 2

  3. KETERASINGAN DALAM FILM WALL-E

    Directory of Open Access Journals (Sweden)

    Rahmadya Putra Nugraha

    2017-05-01

    Full Text Available Modern society nowadays technological advances at first create efficiency in human life. Further development of the technology thus drown human in a routine and automation of work created. The State is to be one of the causes of man separated from fellow or the outside world and eventually experiencing alienation. The movie as a mass media function to obtain the movie and entertainment can be informative or educative function is contained, even persuasive. The purpose of this research was conducted to find out the alienation in the movie Wall E. The concepts used to analyze the movie Wall E this is communication, movie, and alienation. The concept of alienation of human alienation from covering its own products of human alienation from its activities, the human alienation from nature of his humanity and human alienation from each other. Paradigm used is a critical paradigm with type a descriptive research with qualitative approach. The method used is the analysis of semiotics Roland Barthes to interpretation the scope of social alienation and fellow humans in the movie.This writing research results found that alienation of humans with other humans influenced the development of the technology and how the human it self represented of technology, not from our fellow human beings. Masyarakat modern saat ini kemajuan teknologi pada awalnya membuat efisiensi dalam kehidupan manusia. Perkembangan selanjutnya teknologi justru menenggelamkan manusia dalam suatu rutinitas dan otomatisasi kerja yang diciptakan. Keadaan itulah yang menjadi salah satu penyebab manusia terpisah dari sesama atau dunia luar dan akhirnya mengalami keterasingan. Film sebagai media massa berfungsi untuk memperoleh hiburan dan dalam film dapat terkandung fungsi informatif maupun edukatif, bahkan persuasif. Tujuan Penelitian ini dilakukan untuk mengetahui Keterasingan dalam film Wall E. Konsep-konsep yang digunakan untuk menganalisis film Wall E ini adalah komunikasi, film, dan

  4. Scoliosis secondary to an unusual rib lesion.

    LENUS (Irish Health Repository)

    Burke, N G

    2012-04-01

    Tumours of the chest wall are uncommon and are usually malignant. A bone haemangioma is a rare benign vascular neoplasm, which more commonly occurs in middle-aged patients. We present the case of a scoliosis caused by a rib haemangioma in an adolescent male. Other causes of scoliosis secondary to rib lesions are discussed.

  5. Identification of a Classical Mutant in the Industrial Host Aspergillus niger by Systems Genetics: LaeA Is Required for Citric Acid Production and Regulates the Formation of Some Secondary Metabolites

    Directory of Open Access Journals (Sweden)

    Jing Niu

    2016-01-01

    Full Text Available The asexual filamentous fungus Aspergillus niger is an important industrial cell factory for citric acid production. In this study, we genetically characterized a UV-generated A. niger mutant that was originally isolated as a nonacidifying mutant, which is a desirable trait for industrial enzyme production. Physiological analysis showed that this mutant did not secrete large amounts of citric acid and oxalic acid, thus explaining the nonacidifying phenotype. As traditional complementation approaches to characterize the mutant genotype were unsuccessful, we used bulk segregant analysis in combination with high-throughput genome sequencing to identify the mutation responsible for the nonacidifying phenotype. Since A. niger has no sexual cycle, parasexual genetics was used to generate haploid segregants derived from diploids by loss of whole chromosomes. We found that the nonacidifying phenotype was caused by a point mutation in the laeA gene. LaeA encodes a putative methyltransferase-domain protein, which we show here to be required for citric acid production in an A. niger lab strain (N402 and in other citric acid production strains. The unexpected link between LaeA and citric acid production could provide new insights into the transcriptional control mechanisms related to citric acid production in A. niger. Interestingly, the secondary metabolite profile of a ΔlaeA strain differed from the wild-type strain, showing both decreased and increased metabolite levels, indicating that LaeA is also involved in regulating the production of secondary metabolites. Finally, we show that our systems genetics approach is a powerful tool to identify trait mutations.

  6. Identification of a Classical Mutant in the Industrial Host Aspergillus niger by Systems Genetics: LaeA Is Required for Citric Acid Production and Regulates the Formation of Some Secondary Metabolites.

    Science.gov (United States)

    Niu, Jing; Arentshorst, Mark; Nair, P Deepa S; Dai, Ziyu; Baker, Scott E; Frisvad, Jens C; Nielsen, Kristian F; Punt, Peter J; Ram, Arthur F J

    2015-11-13

    The asexual filamentous fungus Aspergillus niger is an important industrial cell factory for citric acid production. In this study, we genetically characterized a UV-generated A. niger mutant that was originally isolated as a nonacidifying mutant, which is a desirable trait for industrial enzyme production. Physiological analysis showed that this mutant did not secrete large amounts of citric acid and oxalic acid, thus explaining the nonacidifying phenotype. As traditional complementation approaches to characterize the mutant genotype were unsuccessful, we used bulk segregant analysis in combination with high-throughput genome sequencing to identify the mutation responsible for the nonacidifying phenotype. Since A. niger has no sexual cycle, parasexual genetics was used to generate haploid segregants derived from diploids by loss of whole chromosomes. We found that the nonacidifying phenotype was caused by a point mutation in the laeA gene. LaeA encodes a putative methyltransferase-domain protein, which we show here to be required for citric acid production in an A. niger lab strain (N402) and in other citric acid production strains. The unexpected link between LaeA and citric acid production could provide new insights into the transcriptional control mechanisms related to citric acid production in A. niger. Interestingly, the secondary metabolite profile of a ΔlaeA strain differed from the wild-type strain, showing both decreased and increased metabolite levels, indicating that LaeA is also involved in regulating the production of secondary metabolites. Finally, we show that our systems genetics approach is a powerful tool to identify trait mutations. Copyright © 2016 Niu et al.

  7. A Gibberellin-Mediated DELLA-NAC Signaling Cascade Regulates Cellulose Synthesis in Rice[OPEN

    Science.gov (United States)

    Huang, Debao; Wang, Shaogan; Zhang, Baocai; Shang-Guan, Keke; Shi, Yanyun; Zhang, Dongmei; Liu, Xiangling; Wu, Kun; Xu, Zuopeng; Fu, Xiangdong; Zhou, Yihua

    2015-01-01

    Cellulose, which can be converted into numerous industrial products, has important impacts on the global economy. It has long been known that cellulose synthesis in plants is tightly regulated by various phytohormones. However, the underlying mechanism of cellulose synthesis regulation remains elusive. Here, we show that in rice (Oryza sativa), gibberellin (GA) signals promote cellulose synthesis by relieving the interaction between SLENDER RICE1 (SLR1), a DELLA repressor of GA signaling, and NACs, the top-layer transcription factors for secondary wall formation. Mutations in GA-related genes and physiological treatments altered the transcription of CELLULOSE SYNTHASE genes (CESAs) and the cellulose level. Multiple experiments demonstrated that transcription factors NAC29/31 and MYB61 are CESA regulators in rice; NAC29/31 directly regulates MYB61, which in turn activates CESA expression. This hierarchical regulation pathway is blocked by SLR1-NAC29/31 interactions. Based on the results of anatomical analysis and GA content examination in developing rice internodes, this signaling cascade was found to be modulated by varied endogenous GA levels and to be required for internode development. Genetic and gene expression analyses were further performed in Arabidopsis thaliana GA-related mutants. Altogether, our findings reveal a conserved mechanism by which GA regulates secondary wall cellulose synthesis in land plants and provide a strategy for manipulating cellulose production and plant growth. PMID:26002868

  8. A Gibberellin-Mediated DELLA-NAC Signaling Cascade Regulates Cellulose Synthesis in Rice.

    Science.gov (United States)

    Huang, Debao; Wang, Shaogan; Zhang, Baocai; Shang-Guan, Keke; Shi, Yanyun; Zhang, Dongmei; Liu, Xiangling; Wu, Kun; Xu, Zuopeng; Fu, Xiangdong; Zhou, Yihua

    2015-06-01

    Cellulose, which can be converted into numerous industrial products, has important impacts on the global economy. It has long been known that cellulose synthesis in plants is tightly regulated by various phytohormones. However, the underlying mechanism of cellulose synthesis regulation remains elusive. Here, we show that in rice (Oryza sativa), gibberellin (GA) signals promote cellulose synthesis by relieving the interaction between SLENDER RICE1 (SLR1), a DELLA repressor of GA signaling, and NACs, the top-layer transcription factors for secondary wall formation. Mutations in GA-related genes and physiological treatments altered the transcription of CELLULOSE SYNTHASE genes (CESAs) and the cellulose level. Multiple experiments demonstrated that transcription factors NAC29/31 and MYB61 are CESA regulators in rice; NAC29/31 directly regulates MYB61, which in turn activates CESA expression. This hierarchical regulation pathway is blocked by SLR1-NAC29/31 interactions. Based on the results of anatomical analysis and GA content examination in developing rice internodes, this signaling cascade was found to be modulated by varied endogenous GA levels and to be required for internode development. Genetic and gene expression analyses were further performed in Arabidopsis thaliana GA-related mutants. Altogether, our findings reveal a conserved mechanism by which GA regulates secondary wall cellulose synthesis in land plants and provide a strategy for manipulating cellulose production and plant growth. © 2015 American Society of Plant Biologists. All rights reserved.

  9. pH-Dependent Regulation of the Relaxation Rate of the Radical Anion of the Secondary Quinone Electron Acceptor QB in Photosystem II As Revealed by Fourier Transform Infrared Spectroscopy.

    Science.gov (United States)

    Nozawa, Yosuke; Noguchi, Takumi

    2018-05-15

    Photosystem II (PSII) is a protein complex that performs water oxidation using light energy during photosynthesis. In PSII, electrons abstracted from water are eventually transferred to the secondary quinone electron acceptor, Q B , and upon double reduction, Q B is converted to quinol by binding two protons. Thus, excess electron transfer in PSII increases the pH of the stroma. In this study, to investigate the pH-dependent regulation of the electron flow in PSII, we have estimated the relaxation rate of the Q B - radical anion in the pH region between 5 and 8 by direct monitoring of its population using light-induced Fourier transform infrared difference spectroscopy. The decay of Q B - by charge recombination with the S 2 state of the water oxidation center in PSII membranes was shown to be accelerated at higher pH, whereas that of Q A - examined in the presence of a herbicide was virtually unaffected at pH ≤7.5 and slightly slowed at pH 8. These observations were consistent with the previous studies that included rather indirect monitoring of the Q B - and Q A - decays using fluorescence detection. The accelerated relaxation of Q B - was explained by the shift of a redox equilibrium between Q A - and Q B - to the Q A - side due to the decrease in the redox potential of Q B at higher pH, which is induced by deprotonation of a single amino acid residue near Q B . It is proposed that this pH-dependent Q B - relaxation is one of the mechanisms of electron flow regulation in PSII for its photoprotection.

  10. Kinetic wall from Israel

    Energy Technology Data Exchange (ETDEWEB)

    Godolphin, D.

    1985-05-01

    An unusual solar mass wall is described. At the turn of a handle it can change from a solar energy collector to a heat-blocker. An appropriate name for it might be the rotating prism wall. An example of the moving wall is at work in an adobe test home in Sede Boqer. Behind a large south-facing window stand four large adobe columns that are triangular in plan. One face of each of them is painted black to absorb sunlight, a second is covered with panels of polystyrene insulation, and a third is painted to match the room decor. These columns can rotate. On winter nights, the insulated side faces the glass, keeping heat losses down. The same scheme works in summer to keep heat out of the house. Small windows provide ventilation.

  11. XTH31, Encoding an in Vitro XEH/XET-Active Enzyme, Regulates Aluminum Sensitivity by Modulating in Vivo XET Action, Cell Wall Xyloglucan Content, and Aluminum Binding Capacity in Arabidopsis[W

    Science.gov (United States)

    Zhu, Xiao Fang; Shi, Yuan Zhi; Lei, Gui Jie; Fry, Stephen C.; Zhang, Bao Cai; Zhou, Yi Hua; Braam, Janet; Jiang, Tao; Xu, Xiao Yan; Mao, Chuan Zao; Pan, Yuan Jiang; Yang, Jian Li; Wu, Ping; Zheng, Shao Jian

    2012-01-01

    Xyloglucan endohydrolase (XEH) and xyloglucan endotransglucosylase (XET) activities, encoded by xyloglucan endotransglucosylase-hydrolase (XTH) genes, are involved in cell wall extension by cutting or cutting and rejoining xyloglucan chains, respectively. However, the physiological significance of this biochemical activity remains incompletely understood. Here, we find that an XTH31 T-DNA insertion mutant, xth31, is more Al resistant than the wild type. XTH31 is bound to the plasma membrane and the encoding gene is expressed in the root elongation zone and in nascent leaves, suggesting a role in cell expansion. XTH31 transcript accumulation is strongly downregulated by Al treatment. XTH31 expression in yeast yields a protein with an in vitro XEH:XET activity ratio of >5000:1. xth31 accumulates significantly less Al in the root apex and cell wall, shows remarkably lower in vivo XET action and extractable XET activity, has a lower xyloglucan content, and exhibits slower elongation. An exogenous supply of xyloglucan significantly ameliorates Al toxicity by reducing Al accumulation in the roots, owing to the formation of an Al-xyloglucan complex in the medium, as verified by an obvious change in chemical shift of 27Al-NMR. Taken together, the data indicate that XTH31 affects Al sensitivity by modulating cell wall xyloglucan content and Al binding capacity. PMID:23204407

  12. Timber frame walls

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Brandt, Erik

    2010-01-01

    A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding....... It was found that the specific damages made to the vapour barrier as part of the test did not have any provable effect on the moisture content. In general elements with an intact vapour barrier did not show a critical moisture content at the wind barrier after four years of exposure....

  13. Cause analysis for elbow thinning of the secondary loop feedwater system in PWR NPP

    International Nuclear Information System (INIS)

    Yu Tao; Bian Chunhua; Zhang Wei; Luo Kunjie; Wang Li; Li Yan

    2013-01-01

    Wall thickness of some secondary system pipelines were measured on site during the refueling outages in March 2012. Wall thinning happened in some components of APA system. This paper focused on the cause analysis of an elbow with that phenomenon. Wall thickness was carefully measured in laboratory using ultrasonic thickness meter and found that wall thinning happened nearly all elbows including two abnormal thinning regions. Analytical research was conducted using ICP, stereo microscope, SEM, XRD, ANSYS. The result shows that the cause of wall thinning is flow accelerated corrosion. Based on the analysis result and international research progress, this paper makes some suggestions to avoid and alleviate FAC in the secondary system. (authors)

  14. Investigation of Plant Cell Wall Properties: A Study of Contributions from the Nanoscale to the Macroscale Impacting Cell Wall Recalcitrance

    Science.gov (United States)

    Crowe, Jacob Dillon

    Biochemical conversion of lignocellulosic biomass to fuel ethanol is one of a few challenging, yet opportune technologies that can reduce the consumption of petroleum-derived transportation fuels, while providing parallel reductions in greenhouse gas emissions. Biomass recalcitrance, or resistance to deconstruction, is a major technical challenge that limits effective conversion of biomass to fermentable sugars, often requiring a costly thermochemical pretreatment step to improve biomass deconstruction. Biomass recalcitrance is imparted largely by the secondary cell wall, a complex polymeric matrix of cell wall polysaccharides and aromatic heteropolymers, that provides structural stability to cells and enables plant upright growth. Polymers within the cell wall can vary both compositionally and structurally depending upon plant species and anatomical fraction, and have varied responses to thermochemical pretreatments. Cell wall properties impacting recalcitrance are still not well understood, and as a result, the goal of this dissertation is to investigate structural features of the cell wall contributing to recalcitrance (1) in diverse anatomical fractions of a single species, (2) in response to diverse pretreatments, and (3) resulting from genetic modification. In the first study, feedstock cell wall heterogeneity was investigated in anatomical (stem, leaf sheaths, and leaf blades) and internode fractions of switchgrass at varying tissue maturities. Lignin content was observed as the key contributor to recalcitrance in maturing stem tissues only, with non-cellulosic substituted glucuronoarabinoxylans and pectic polysaccharides contributing to cell wall recalcitrance in leaf sheath and leaf blades. Hydroxycinnamate (i.e., saponifiable p-coumarate and ferulate) content along with xylan and pectin extractability decreased with tissue maturity, suggesting lignification is only one component imparting maturity specific cell wall recalcitrance. In the second study

  15. Building a secondary containment system

    Energy Technology Data Exchange (ETDEWEB)

    Broder, M.F.

    1994-10-01

    Retail fertilizer and pesticide dealers across the United States are installing secondary containment at their facilities or are seriously considering it. Much of this work is in response to new state regulations; however, many dealers not facing new regulations are upgrading their facilities to reduce their liability, lower their insurance costs, or comply with anticipated regulations. The Tennessee Valley Authority`s (TVA) National Fertilizer and Environmental Research Center (NFERC) has assisted dealers in 22 states in retrofitting containment to their facilities. Simultaneous improvements in the operational efficiency of the facilities have been achieved at many of the sites. This paper is based on experience gained in that work and details the rationale used in planning secondary containment and facility modifications.

  16. eWALL

    DEFF Research Database (Denmark)

    Kyriazakos, Sofoklis; Mihaylov, Mihail; Anggorojati, Bayu

    2016-01-01

    challenge with impact in multiple sectors. In this paper we present an innovative ICT solution, named eWALL, that aims to address these challenges by means of an advanced ICT infrastructure and home sensing environment; thus differentiating from existing eHealth and eCare solutions. The system of e...

  17. Abdominal wall surgery

    Science.gov (United States)

    ... as liposuction , which is another way to remove fat. But, abdominal wall surgery is sometimes combined with liposuction. ... from the middle and lower sections of your abdomen to make it firmer ... removes excess fat and skin (love handles) from the sides of ...

  18. Occupy Wall Street

    DEFF Research Database (Denmark)

    Jensen, Michael J.; Bang, Henrik

    2013-01-01

    This article analyzes the political form of Occupy Wall Street on Twitter. Drawing on evidence contained within the profiles of over 50,000 Twitter users, political identities of participants are characterized using natural language processing. The results find evidence of a traditional...

  19. Endometriosis Abdominal wall

    International Nuclear Information System (INIS)

    Alvarez, M.; Carriquiry, L.

    2003-01-01

    Endometriosis of abdominal wall is a rare entity wi ch frequently appears after gynecological surgery. Case history includes three cases of parietal endometriosis wi ch were treated in Maciel Hospital of Montevideo. The report refers to etiological diagnostic aspects and highlights the importance of total resection in order to achieve definitive healing

  20. The effect of thermal conductance of vertical walls on natural convection in a rectangular enclosure

    International Nuclear Information System (INIS)

    Kikuchi, Y.; Yoshino, A.; Taii, K.

    2004-01-01

    This paper deals with the experimental results of natural convective heat transfer in a rectangular water layer bounded by vertical walls of different thermal conductance. The vertical walls were made of copper or stainless steel. A minimum was observed in the horizontal distribution of temperature near the heating wall since a secondary reverse flow occurred outside the boundary layer. For copper case the experimental results of Nusselt number agreed well with calculations under an isothermal wall condition. For stainless steel case, however, the measured values were lower than the calculations since a three-dimensional effect appeared in convection due to non-uniformity in wall temperature. (author)

  1. Chronic Abdominal Wall Pain.

    Science.gov (United States)

    Koop, Herbert; Koprdova, Simona; Schürmann, Christine

    2016-01-29

    Chronic abdominal wall pain is a poorly recognized clinical problem despite being an important element in the differential diagnosis of abdominal pain. This review is based on pertinent articles that were retrieved by a selective search in PubMed and EMBASE employing the terms "abdominal wall pain" and "cutaneous nerve entrapment syndrome," as well as on the authors' clinical experience. In 2% to 3% of patients with chronic abdominal pain, the pain arises from the abdominal wall; in patients with previously diagnosed chronic abdominal pain who have no demonstrable pathological abnormality, this likelihood can rise as high as 30% . There have only been a small number of clinical trials of treatment for this condition. The diagnosis is made on clinical grounds, with the aid of Carnett's test. The characteristic clinical feature is strictly localized pain in the anterior abdominal wall, which is often mischaracterized as a "functional" complaint. In one study, injection of local anesthesia combined with steroids into the painful area was found to relieve pain for 4 weeks in 95% of patients. The injection of lidocaine alone brought about improvement in 83-91% of patients. Long-term pain relief ensued after a single lidocaine injection in 20-30% of patients, after repeated injections in 40-50% , and after combined lidocaine and steroid injections in up to 80% . Pain that persists despite these treatments can be treated with surgery (neurectomy). Chronic abdominal wall pain is easily diagnosed on physical examination and can often be rapidly treated. Any physician treating patients with abdominal pain should be aware of this condition. Further comparative treatment trials will be needed before a validated treatment algorithm can be established.

  2. O magistério de ensino secundário e a regulamentação da profissão (1931-1946 Secondary school teaching and its professional regulation (1931-1946

    Directory of Open Access Journals (Sweden)

    Amália Dias

    2012-03-01

    Full Text Available Apresentamos as políticas públicas destinadas a regular o estatuto econômico do magistério particular de Ensino Secundário, em face do contexto histórico de organização das relações trabalhistas e da expansão do setor privado no ensino no pós-1930. A partir da atuação do associativismo docente, examinamos as correlações de força entre órgãos do governo, empregadores e magistério particular na definição de contratos de trabalho e registro profissional, posto que a legislação é produto de relações sociais e de poder. Sob a égide do governo federal, essas relações foram canalizadas para o interior das agências estatais, o que, contudo, não anulou as dimensões de conflito intraestatais e entre sujeitos coletivos organizados que encaminharam suas propostas, manifestaram resistências, articularam alianças e disputaram a hegemonia do processo decisório.The public policies intended to regulate the economic state of private teaching in secondary education are presented, with the historical context of its (secondary education's organization, in mind, including its working relations and the expansion of the private sector in teaching post-1930. From the teaching association's performance, we are able to examine the correlative forces between the government agencies, employers and the teaching profession, in the definition of work contracts and professional register, since it follows that legislation is a product of social relations and power. Under the aegis of the federal government, these relations have become part of the remit of state agencies, but this, in actual fact, hasn't eradicated the dimension of interstate conflict and, between the organized collective subjects that have forwarded their proposals, resistance has become apparent, alliances have been articulated and the hegemony of the decision-making process has been disputed by them.

  3. Incisional subcutaneous endometrioma of the abdominal wall: report of two cases

    International Nuclear Information System (INIS)

    Merran, S.; Karila-Cohen, P.

    2004-01-01

    Endometriosis occurs in up to 15% of menstruating women. Abdominal wall involvement is rare and always secondary to an invasive procedure. The authors report the imaging and clinical findings of two patients with subcutaneous endometrioma following cesarean section. (author)

  4. Wind tunnels with adapted walls for reducing wall interference

    Science.gov (United States)

    Ganzer, U.

    1979-01-01

    The basic principle of adaptable wind tunnel walls is explained. First results of an investigation carried out at the Aero-Space Institute of Berlin Technical University are presented for two dimensional flexible walls and a NACA 0012 airfoil. With five examples exhibiting very different flow conditions it is demonstrated that it is possible to reduce wall interference and to avoid blockage at transonic speeds by wall adaptation.

  5. Rising damp in building walls: the wall base ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, A.S.; Delgado, J.M.P.Q.; Freitas, V.P. de [Faculdade de Engenharia da Universidade do Porto, Laboratorio de Fisica das Construcoes (LFC), Departamento de Engenharia Civil, Porto (Portugal)

    2012-12-15

    This work intends to validate a new system for treating rising damp in historic buildings walls. The results of laboratory experiments show that an efficient way of treating rising damp is by ventilating the wall base, using the HUMIVENT technique. The analytical model presented describes very well the observed features of rising damp in walls, verified by laboratory tests, who contributed for a simple sizing of the wall base ventilation system that will be implemented in historic buildings. (orig.)

  6. Cold Abscess of the Anterior Abdominal Wall: An Unusual Primary ...

    African Journals Online (AJOL)

    Autopsy studies have shown abdominal wall involvement in less than 1% of patients who died of tuberculosis. Antitubercular therapy is main form of management. Surgical intervention is always secondary in the form of either sonography or computerized tomography-guided aspiration or open drainage which is usually ...

  7. Preoperative steroid in abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim; Brøndum, Tina Lee; Belhage, Bo

    2016-01-01

    INTRODUCTION: Preoperative administration of high-dose glucocorticoid leads to improved recovery and decreased length of stay after abdominal surgery. Even so, studies on administration of glucocorticoids for patients undergoing abdominal wall reconstruction (AWR) for giant ventral hernia repair...... defect exceeding 10 cm will be randomised for intravenous administration of either 125 mg methylprednisolone or saline at the induction of anaesthesia. The primary endpoint is pain at rest on the first post-operative day. Patients will be followed until 30 days post-operatively, and secondary outcomes...

  8. High-R Walls for Remodeling: Wall Cavity Moisture Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  9. High-R Walls for Remodeling. Wall Cavity Moisture Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Kochkin, V. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  10. Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, Daniel J.

    2015-11-25

    The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the ‘Young's modulus’ of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

  11. Changes in Cell Wall Polysaccharides Associated With Growth 1

    Science.gov (United States)

    Nevins, Donald J.; English, Patricia D.; Albersheim, Peter

    1968-01-01

    Changes in the polysaccharide composition of Phaseolus vulgaris, P. aureus, and Zea mays cell walls were studied during the first 28 days of seedling development using a gas chromatographic method for the analysis of neutral sugars. Acid hydrolysis of cell wall material from young tissues liberates rhamnose, fucose, arabinose, xylose, mannose, galactose, and glucose which collectively can account for as much as 70% of the dry weight of the wall. Mature walls in fully expanded tissues of these same plants contain less of these constituents (10%-20% of dry wt). Gross differences are observed between developmental patterns of the cell wall in the various parts of a seedling, such as root, stem, and leaf. The general patterns of wall polysaccharide composition change, however, are similar for analogous organs among the varieties of a species. Small but significant differences in the rates of change in sugar composition were detected between varieties of the same species which exhibited different growth patterns. The cell walls of species which are further removed phylogenetically exhibit even more dissimilar developmental patterns. The results demonstrate the dynamic nature of the cell wall during growth as well as the quantitative and qualitative exactness with which the biosynthesis of plant cell walls is regulated. PMID:16656862

  12. The Specific Nature of Plant Cell Wall Polysaccharides 1

    Science.gov (United States)

    Nevins, Donald J.; English, Patricia D.; Albersheim, Peter

    1967-01-01

    Polysaccharide compositions of cell walls were assessed by quantitative analyses of the component sugars. Cell walls were hydrolyzed in 2 n trifluoroacetic acid and the liberated sugars reduced to their respective alditols. The alditols were acetylated and the resulting alditol acetates separated by gas chromatography. Quantitative assay of the alditol acetates was accomplished by electronically integrating the detector output of the gas chromatograph. Myo-inositol, introduced into the sample prior to hydrolysis, served as an internal standard. The cell wall polysaccharide compositions of plant varieties within a given species are essentially identical. However, differences in the sugar composition were observed in cell walls prepared from different species of the same as well as of different genera. The fact that the wall compositions of different varieties of the same species are the same indicates that the biosynthesis of cell wall polysaccharides is genetically regulated. The cell walls of various morphological parts (roots, hypocotyls, first internodes and primary leaves) of bean plants were each found to have a characteristic sugar composition. It was found that the cell wall sugar composition of suspension-cultured sycamore cells could be altered by growing the cells on different carbon sources. This demonstrates that the biosynthesis of cell wall polysaccharides can be manipulated without fatal consequences. PMID:16656594

  13. Spray impingement on a wall in the context of the upper airways

    OpenAIRE

    Boudin , Laurent; Weynans , Lisl

    2008-01-01

    9 pages; ESAIM proceedings; We here address the modelling of an aerosol hitting the walls of the airways or an endotracheal tube used for a mechanical ventilation, and the possible creation of secondary droplets that may follow. We present a kinetic modelling of the spray-wall interaction and propose a boundary term that takes into account the possible formation of secondary droplets. Next we answer the following question: when, modelling the delivery of solute therapeutic aerosols, is it nec...

  14. Wall insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Kostek, P.T.

    1987-08-11

    In a channel specially designed to fasten semi-rigid mineral fibre insulation to masonry walls, it is known to be constructed from 20 gauge galvanized steel or other suitable material. The channel is designed to have pre-punched holes along its length for fastening of the channel to the drywall screw. The unique feature of the channel is the teeth running along its length which are pressed into the surface of the butted together sections of the insulation providing a strong grip between the two adjacent pieces of insulation. Of prime importance to the success of this system is the recent technological advancements of the mineral fibre itself which allow the teeth of the channel to engage the insulation fully and hold without mechanical support, rather than be repelled or pushed back by the inherent nature of the insulation material. After the insulation is secured to the masonry wall by concrete nail fastening systems, the drywall is screwed to the channel.

  15. Shadows on the wall

    International Nuclear Information System (INIS)

    Swift, Diana.

    1984-01-01

    Canadian antinuclear groups, because of their shifting stances and fluid overlapping membership, are compared with shadows on a wall. They can be roughly classified as environmental, pacifist, concerned with energy, religious, or dedicated to nuclear responsibility. The author considers that such groups, despite their arguably unrealistic attitudes, have raised public awareness of the ethical, practical and financial aspects of power development in Canada and the world

  16. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason; Johnson, Andrew; Renambot, Luc; Peterka, Tom; Jeong, Byungil; Sandin, Daniel J.; Talandis, Jonas; Jagodic, Ratko; Nam, Sungwon; Hur, Hyejung; Sun, Yiwen

    2013-01-01

    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  17. Light shining through walls

    International Nuclear Information System (INIS)

    Redondo, Javier; Ringwald, Andreas

    2010-11-01

    Shining light through walls? At first glance this sounds crazy. However, very feeble gravitational and electroweak effects allow for this exotic possibility. Unfortunately, with present and near future technologies the opportunity to observe light shining through walls via these effects is completely out of question. Nevertheless there are quite a number of experimental collaborations around the globe involved in this quest. Why are they doing it? Are there additional ways of sending photons through opaque matter? Indeed, various extensions of the standard model of particle physics predict the existence of new particles called WISPs - extremely weakly interacting slim particles. Photons can convert into these hypothetical particles, which have no problems to penetrate very dense materials, and these can reconvert into photons after their passage - as if light was effectively traversing walls. We review this exciting field of research, describing the most important WISPs, the present and future experiments, the indirect hints from astrophysics and cosmology pointing to the existence of WISPs, and finally outlining the consequences that the discovery of WISPs would have. (orig.)

  18. Light shining through walls

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Max-Planck-Institut fuer Physik, Muenchen (Germany); Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-11-15

    Shining light through walls? At first glance this sounds crazy. However, very feeble gravitational and electroweak effects allow for this exotic possibility. Unfortunately, with present and near future technologies the opportunity to observe light shining through walls via these effects is completely out of question. Nevertheless there are quite a number of experimental collaborations around the globe involved in this quest. Why are they doing it? Are there additional ways of sending photons through opaque matter? Indeed, various extensions of the standard model of particle physics predict the existence of new particles called WISPs - extremely weakly interacting slim particles. Photons can convert into these hypothetical particles, which have no problems to penetrate very dense materials, and these can reconvert into photons after their passage - as if light was effectively traversing walls. We review this exciting field of research, describing the most important WISPs, the present and future experiments, the indirect hints from astrophysics and cosmology pointing to the existence of WISPs, and finally outlining the consequences that the discovery of WISPs would have. (orig.)

  19. Microfluidics with fluid walls.

    Science.gov (United States)

    Walsh, Edmond J; Feuerborn, Alexander; Wheeler, James H R; Tan, Ann Na; Durham, William M; Foster, Kevin R; Cook, Peter R

    2017-10-10

    Microfluidics has great potential, but the complexity of fabricating and operating devices has limited its use. Here we describe a method - Freestyle Fluidics - that overcomes many key limitations. In this method, liquids are confined by fluid (not solid) walls. Aqueous circuits with any 2D shape are printed in seconds on plastic or glass Petri dishes; then, interfacial forces pin liquids to substrates, and overlaying an immiscible liquid prevents evaporation. Confining fluid walls are pliant and resilient; they self-heal when liquids are pipetted through them. We drive flow through a wide range of circuits passively by manipulating surface tension and hydrostatic pressure, and actively using external pumps. Finally, we validate the technology with two challenging applications - triggering an inflammatory response in human cells and chemotaxis in bacterial biofilms. This approach provides a powerful and versatile alternative to traditional microfluidics.The complexity of fabricating and operating microfluidic devices limits their use. Walsh et al. describe a method in which circuits are printed as quickly and simply as writing with a pen, and liquids in them are confined by fluid instead of solid walls.

  20. Wall Street som kreationistisk forkynder

    DEFF Research Database (Denmark)

    Ekman, Susanne

    2016-01-01

    Artiklen gennemgår Karen Hos etnografi om Wall Street: "Liquidated: An ethnography of Wall Street" set i lyset af den offentlige debat vedrørende Goldman Sachs opkøb af Dong......Artiklen gennemgår Karen Hos etnografi om Wall Street: "Liquidated: An ethnography of Wall Street" set i lyset af den offentlige debat vedrørende Goldman Sachs opkøb af Dong...

  1. Seasonal and clonal variation in cellulose microfibril orientation during cell wall formation of tracheids in Cryptomeria japonica.

    Science.gov (United States)

    Jyske, Tuula; Fujiwara, Takeshi; Kuroda, Katsushi; Iki, Taiichi; Zhang, Chunhua; Jyske, Tuomas K; Abe, Hisashi

    2014-08-01

    To investigate the biological mechanism by which trees control the changes in microfibril (MF) orientation among secondary cell wall layers of conifer tracheids, we studied seasonal variation in the orientation of newly deposited MFs during tracheid cell wall development in Japanese cedar (Cryptomeria japonica D. Don) trees growing in Central Japan (36°36'N, 140°39'E). Sample blocks were repeatedly collected from four 16-year-old clones of different origins during the growing season of 2010 to investigate the hypotheses that changes in cellulose MF orientation between wall layers exhibited seasonal and clonal differences. The progressive change in the orientation of newly deposited MFs on the primary and secondary cell wall layers of tracheids was detected by field-emission-scanning electron microscopy. Tracheid production and differentiation was studied by light microscopy. We observed a decreasing trend in the orientation of deposited MFs from earlywood to latewood in the S2 and S1 layers, where MFs appeared in a Z-helix. In contrast, no seasonal pattern in the orientation of the MFs in the S-helix was observed. Minor clonal variation was observed in the phenology of tracheid production and differentiation. We concluded that a seasonal decreasing trend in the orientation of the MFs in the Z-helix in S1 and S2 was present, whereas the MFs in other layers exhibited minor random variations. Thus, the orientation of the MFs in S2 was affected by seasonal factors, whereas the MFs in other layers were more intrinsically controlled. The within-ring variations in the MF orientation and thus the resulting average MF angle might also be related to genotypic differences in the tracheid production and differentiation rate. However, our results do not exclude other intrinsic and environmental regulations in the change in MF orientation, which remains a topic for future studies. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions

  2. Build an Interactive Word Wall

    Science.gov (United States)

    Jackson, Julie

    2018-01-01

    Word walls visually display important vocabulary covered during class. Although teachers have often been encouraged to post word walls in their classrooms, little information is available to guide them. This article describes steps science teachers can follow to transform traditional word walls into interactive teaching tools. It also describes a…

  3. Brassinosteroid Mediated Cell Wall Remodeling in Grasses under Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Xiaolan Rao

    2017-05-01

    Full Text Available Unlike animals, plants, being sessile, cannot escape from exposure to severe abiotic stresses such as extreme temperature and water deficit. The dynamic structure of plant cell wall enables them to undergo compensatory changes, as well as maintain physical strength, with changing environments. Plant hormones known as brassinosteroids (BRs play a key role in determining cell wall expansion during stress responses. Cell wall deposition differs between grasses (Poaceae and dicots. Grass species include many important food, fiber, and biofuel crops. In this article, we focus on recent advances in BR-regulated cell wall biosynthesis and remodeling in response to stresses, comparing our understanding of the mechanisms in grass species with those in the more studied dicots. A more comprehensive understanding of BR-mediated changes in cell wall integrity in grass species will benefit the development of genetic tools to improve crop productivity, fiber quality and plant biomass recalcitrance.

  4. Reduced activation calculations for the STARFIRE first wall

    International Nuclear Information System (INIS)

    Mann, F.M.

    1983-10-01

    The activation of 27 elements (Li, Be, B, C, N, O, Mg, Al, Si, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, Hf, Ta, W, and Pb) was calculated for a two-year exposure at the STARFIRE first-wall position. Based on a reasonable extension of current NRC regulations for near-surface land disposal, restrictions on N, Al, Ni, Cu, Nb, Mo, and Pb concentrations in first-wall materials may be required

  5. Cell Wall Metabolism in Response to Abiotic Stress

    Science.gov (United States)

    Gall, Hyacinthe Le; Philippe, Florian; Domon, Jean-Marc; Gillet, Françoise; Pelloux, Jérôme; Rayon, Catherine

    2015-01-01

    This review focuses on the responses of the plant cell wall to several abiotic stresses including drought, flooding, heat, cold, salt, heavy metals, light, and air pollutants. The effects of stress on cell wall metabolism are discussed at the physiological (morphogenic), transcriptomic, proteomic and biochemical levels. The analysis of a large set of data shows that the plant response is highly complex. The overall effects of most abiotic stress are often dependent on the plant species, the genotype, the age of the plant, the timing of the stress application, and the intensity of this stress. This shows the difficulty of identifying a common pattern of stress response in cell wall architecture that could enable adaptation and/or resistance to abiotic stress. However, in most cases, two main mechanisms can be highlighted: (i) an increased level in xyloglucan endotransglucosylase/hydrolase (XTH) and expansin proteins, associated with an increase in the degree of rhamnogalacturonan I branching that maintains cell wall plasticity and (ii) an increased cell wall thickening by reinforcement of the secondary wall with hemicellulose and lignin deposition. Taken together, these results show the need to undertake large-scale analyses, using multidisciplinary approaches, to unravel the consequences of stress on the cell wall. This will help identify the key components that could be targeted to improve biomass production under stress conditions. PMID:27135320

  6. Electroweak bubble wall speed limit

    Energy Technology Data Exchange (ETDEWEB)

    Bödeker, Dietrich [Fakultät für Physik, Universität Bielefeld, 33501 Bielefeld (Germany); Moore, Guy D., E-mail: bodeker@physik.uni-bielefeld.de, E-mail: guymoore@ikp.physik.tu-darmstadt.de [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 2, 64289 Darmstadt (Germany)

    2017-05-01

    In extensions of the Standard Model with extra scalars, the electroweak phase transition can be very strong, and the bubble walls can be highly relativistic. We revisit our previous argument that electroweak bubble walls can 'run away,' that is, achieve extreme ultrarelativistic velocities γ ∼ 10{sup 14}. We show that, when particles cross the bubble wall, they can emit transition radiation. Wall-frame soft processes, though suppressed by a power of the coupling α, have a significance enhanced by the γ-factor of the wall, limiting wall velocities to γ ∼ 1/α. Though the bubble walls can move at almost the speed of light, they carry an infinitesimal share of the plasma's energy.

  7. CLD1/SRL1 modulates leaf rolling by affecting cell wall formation, epidermis integrity and water homeostasis in rice.

    Science.gov (United States)

    Li, Wen-Qiang; Zhang, Min-Juan; Gan, Peng-Fei; Qiao, Lei; Yang, Shuai-Qi; Miao, Hai; Wang, Gang-Feng; Zhang, Mao-Mao; Liu, Wen-Ting; Li, Hai-Feng; Shi, Chun-Hai; Chen, Kun-Ming

    2017-12-01

    Leaf rolling is considered as one of the most important agronomic traits in rice breeding. It has been previously reported that SEMI-ROLLED LEAF 1 (SRL1) modulates leaf rolling by regulating the formation of bulliform cells in rice (Oryza sativa); however, the regulatory mechanism underlying SRL1 has yet to be further elucidated. Here, we report the functional characterization of a novel leaf-rolling mutant, curled leaf and dwarf 1 (cld1), with multiple morphological defects. Map-based cloning revealed that CLD1 is allelic with SRL1, and loses function in cld1 through DNA methylation. CLD1/SRL1 encodes a glycophosphatidylinositol (GPI)-anchored membrane protein that modulates leaf rolling and other aspects of rice growth and development. The cld1 mutant exhibits significant decreases in cellulose and lignin contents in secondary cell walls of leaves, indicating that the loss of function of CLD1/SRL1 affects cell wall formation. Furthermore, the loss of CLD1/SRL1 function leads to defective leaf epidermis such as bulliform-like epidermal cells. The defects in leaf epidermis decrease the water-retaining capacity and lead to water deficits in cld1 leaves, which contribute to the main cause of leaf rolling. As a result of the more rapid water loss and lower water content in leaves, cld1 exhibits reduced drought tolerance. Accordingly, the loss of CLD1/SRL1 function causes abnormal expression of genes and proteins associated with cell wall formation, cuticle development and water stress. Taken together, these findings suggest that the functional roles of CLD1/SRL1 in leaf-rolling regulation are closely related to the maintenance of cell wall formation, epidermal integrity and water homeostasis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  8. Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaojing [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China); Xu, Yonghong [Institute of Ophthalmological Research, Department of Ophthalmology, Renmin Hospital of Wuhan University, 430060 Wuhan (China); Meng, Xiangning [School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Watari, Fumio [Department of Biomedical, Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Liu, Hudan, E-mail: hudanliu@hust.edu.cn [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China); Chen, Xiao, E-mail: mornsmile@yahoo.com [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan (China)

    2015-01-01

    Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, β-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

  9. 40 CFR 133.105 - Treatment equivalent to secondary treatment.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Treatment equivalent to secondary treatment. 133.105 Section 133.105 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS SECONDARY TREATMENT REGULATION § 133.105 Treatment equivalent to secondary treatment...

  10. 7 CFR 930.57 - Secondary inventory reserve.

    Science.gov (United States)

    2010-01-01

    ... shall retain control over the release of any cherries from the secondary inventory reserve. No cherries... 7 Agriculture 8 2010-01-01 2010-01-01 false Secondary inventory reserve. 930.57 Section 930.57... Handling Regulations § 930.57 Secondary inventory reserve. (a) In the event the inventory reserve...

  11. Enhanced wall pumping in JET

    International Nuclear Information System (INIS)

    Ehrenberg, J.; Harbour, P.J.

    1991-01-01

    The enhanced wall pumping phenomenon in JET is observed for hydrogen or deuterium plasmas which are moved from the outer (larger major radius) limiter position either to the inner wall or to the top/bottom wall of the vacuum vessel. This phenomenon is analysed by employing a particle recycling model which combines plasma particle transport with particle re-emission from and retention within material surfaces. The model calculates the important experimentally observable quantities, such as particle fluxes, global particle confinement time, plasma density and density profile. Good qualitative agreement is found and, within the uncertainties, the agreement is quantitative if the wall pumping is assumed to be caused by two simultaneously occurring effects: (1) Neutral particle screening at the inner wall and the top/bottom wall is larger than that at the outer limiter because of different magnetic topologies at different poloidal positions; and (2) although most of the particles (≥ 90%) impacting on the wall can be promptly re-emitted, a small fraction (≤ 10%) of them must be retained in the wall for a period of time which is similar to or larger than the global plasma particle confinement time. However, the wall particle retention time need not be different from that of the outer limiter, i.e. pumping can occur when there is no difference between the material properties of the limiter and those of the wall. (author). 45 refs, 18 figs

  12. Characteristics of wall pressure over wall with permeable coating

    Energy Technology Data Exchange (ETDEWEB)

    Song, Woo Seog; Shin, Seungyeol; Lee, Seungbae [Inha Univ., Incheon (Korea, Republic of)

    2012-11-15

    Fluctuating wall pressures were measured using an array of 16 piezoelectric transducers beneath a turbulent boundary layer. The coating used in this experiment was an open cell, urethane type foam with a porosity of approximately 50 ppi. The ultimate objective of the coating is to provide a mechanical filter to reduce the wall pressure fluctuations. The ultimate objective of the coating is to provide a mechanical filter to reduce the wall pressure fluctuations. The boundary layer on the flat plate was measured by using a hot wire probe, and the CPM method was used to determine the skin friction coefficient. The wall pressure autospectra and streamwise wavenumber frequency spectra were compared to assess the attenuation of the wall pressure field by the coating. The coating is shown to attenuate the convective wall pressure energy. However, the relatively rough surface of the coating in this investigation resulted in a higher mean wall shear stress, thicker boundary layer, and higher low frequency wall pressure spectral levels compared to a smooth wall.

  13. Size, Shape, and Arrangement of Cellulose Microfibril in Higher Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Ding, S. Y.

    2013-01-01

    Plant cell walls from maize (Zea mays L.) are imaged using atomic force microscopy (AFM) at the sub-nanometer resolution. We found that the size and shape of fundamental cellulose elementary fibril (CEF) is essentially identical in different cell wall types, i.e., primary wall (PW), parenchyma secondary wall (pSW), and sclerenchyma secondary wall (sSW), which is consistent with previously proposed 36-chain model (Ding et al., 2006, J. Agric. Food Chem.). The arrangement of individual CEFs in these wall types exhibits two orientations. In PW, CEFs are horizontally associated through their hydrophilic faces, and the planar faces are exposed, forming ribbon-like macrofibrils. In pSW and sSW, CEFs are vertically oriented, forming layers, in which hemicelluloses are interacted with the hydrophobic faces of the CEF and serve as spacers between CEFs. Lignification occurs between CEF-hemicelluloses layers in secondary walls. Furthermore, we demonstrated quantitative analysis of plant cell wall accessibility to and digestibility by different cellulase systems at real-time using chemical imaging (e.g., stimulated Raman scattering) and fluorescence microscopy of labeled cellulases (Ding et al., 2012, Science, in press).

  14. Wood cell-wall structure requires local 2D-microtubule disassembly by a novel plasma membrane-anchored protein.

    Science.gov (United States)

    Oda, Yoshihisa; Iida, Yuki; Kondo, Yuki; Fukuda, Hiroo

    2010-07-13

    Plant cells have evolved cortical microtubules, in a two-dimensional space beneath the plasma membrane, that regulate patterning of cellulose deposition. Although recent studies have revealed that several microtubule-associated proteins facilitate self-organization of transverse cortical microtubules, it is still unknown how diverse patterns of cortical microtubules are organized in different xylem cells, which are the major components of wood. Using our newly established in vitro xylem cell differentiation system, we found that a novel microtubule end-tracking protein, microtubule depletion domain 1 (MIDD1), was anchored to distinct plasma membrane domains and promoted local microtubule disassembly, resulting in pits on xylem cell walls. The introduction of RNA interference for MIDD1 resulted in the failure of local microtubule depletion and the formation of secondary walls without pits. Conversely, the overexpression of MIDD1 reduced microtubule density. MIDD1 has two coiled-coil domains for the binding to microtubules and for the anchorage to plasma membrane domains, respectively. Combination of the two coils caused end tracking of microtubules during shrinkage and suppressed their rescue events. Our results indicate that MIDD1 integrates spatial information in the plasma membrane with cortical microtubule dynamics for determining xylem cell wall pattern. Copyright 2010 Elsevier Ltd. All rights reserved.

  15. Abdominal wall blocks in adults

    DEFF Research Database (Denmark)

    Børglum, Jens; Gögenür, Ismail; Bendtsen, Thomas F

    2016-01-01

    been introduced with success. Future research should also investigate the effect of specific abdominal wall blocks on neuroendocrine and inflammatory stress response after surgery.  Summary USG abdominal wall blocks in adults are commonplace techniques today. Most abdominal wall blocks are assigned......Purpose of review Abdominal wall blocks in adults have evolved much during the last decade; that is, particularly with the introduction of ultrasound-guided (USG) blocks. This review highlights recent advances of block techniques within this field and proposes directions for future research.......  Recent findings Ultrasound guidance is now considered the golden standard for abdominal wall blocks in adults, even though some landmark-based blocks are still being investigated. The efficiency of USG transversus abdominis plane blocks in relation to many surgical procedures involving the abdominal wall...

  16. A mobility based vibroacoustic energy transmission simulation into an enclosure through a double-wall panel.

    Science.gov (United States)

    Sahu, Atanu; Bhattacharya, Partha; Niyogi, Arup Guha; Rose, Michael

    2017-06-01

    Double-wall panels are known for their superior sound insulation properties over single wall panels as a sound barrier. The sound transmission phenomenon through a double-wall structure is a complex process involving vibroacoustic interaction between structural panels, the air-cushion in between, and the secondary acoustic domain. It is in this context a versatile and a fully coupled technique based on the finite-element-boundary element model is developed that enables estimation of sound transfer through a double-wall panel into an adjacent enclosure while satisfying the displacement compatibility across the interface. The contribution of individual components in the transmitted energy is identified through numerical simulations.

  17. Radiation shielding wall structure

    International Nuclear Information System (INIS)

    Nishimura, Yoshitaka; Oka, Shinji; Kan, Toshihiko; Misato, Takeshi.

    1990-01-01

    A space between a pair of vertical steel plates laterally disposed in parallel at an optional distance has a structure of a plurality of vertically extending tranks partitioned laterally by vertically placed steel plates. Then, cements are grouted to the tranks. Strip-like steel plates each having a thickness greater than the gap between the each of the vertically placed steel plates and the cement are bonded each at the surface for each of the vertically placed steel plates opposing to the cements. A protrusion of a strip width having radiation shielding performance substantially identical with that by the thickness of the cement is disposed in the strip-like steel plates. With such a constitution, a safety radiation shielding wall structure with no worry of radiation intrusion to gaps, if formed, between the steel plates and the grouted cements due to shrinkage of the cements. (I.N.)

  18. Observations on resistive wall modes

    International Nuclear Information System (INIS)

    Gerwin, R.A.; Finn, J.M.

    1996-01-01

    Several results on resistive wall modes and their application to tokamaks are presented. First, it is observed that in the presence of collisional parallel dynamics there is an exact cancellation to lowest order of the dissipative and sound wave effects for an ideal Ohm's law. This is easily traced to the fact that the parallel dynamics occurs along the perturbed magnetic field lines for such electromagnetic modes. Such a cancellation does not occur in the resistive layer of a tearing-like mode. The relevance to models for resistive wall modes using an electrostatic Hammett-Perkins type operator to model Landau damping will be discussed. Second, we observe that with an ideal Ohm's law, resistive wall modes can be destabilized by rotation in that part of parameter space in which the ideal MHD modes are stable with the wall at infinity. This effect can easily be explained by interpreting the resistive wall instability in terms of mode coupling between the backward stable MHD mode and a stable mode locked into the wall. Such an effect can occur for very small rotation for tearing-resistive wall modes in which inertia dominates viscosity in the layer, but the mode is stabilized by further rotation. For modes for which viscosity dominates in the layer, rotation is purely stabilizing. For both tearing models, a somewhat higher rotation frequency gives stability essentially whenever the tearing mode is stable with a perfectly conducting wall. These tearing/resistive wall results axe also simply explained in terms of mode coupling. It has been shown that resonant external ideal modes can be stabilized in the presence of resistive wall and resistive plasma with rotation of order the nominal tearing mode growth rate. We show that these modes behave as resistive wall tearing modes in the sense above. This strengthens the suggestion that rotational stabilization of the external kink with a resistive wall is due to the presence of resistive layers, even for ideal modes

  19. Characteristic Thickened Cell Walls of the Bracts of the ‘Eternal Flower’ Helichrysum bracteatum

    Science.gov (United States)

    Nishikawa, Kuniko; Ito, Hiroaki; Awano, Tatsuya; Hosokawa, Munetaka; Yazawa, Susumu

    2008-01-01

    Background and Aims Helichrysum bracteatum is called an ‘eternal flower’ and has large, coloured, scarious bracts. These maintain their aesthetic value without wilting or discoloration for many years. There have been no research studies of cell death or cell morphology of the scarious bract, and hence the aim of this work was to elucidate these characteristics for the bract of H. bracteatum. Methods DAPI (4'6-diamidino-2-phenylindol dihydrochloride) staining and fluorescence microscopy were used for observation of cell nuclei. Light microscopy (LM), transmission electron microscopy (TEM) and polarized light microscopy were used for observation of cells, including cell wall morphology. Key Results Cell death occurred at the bract tip during the early stage of flower development. The cell wall was the most prominent characteristic of H. bracteatum bract cells. Characteristic thickened secondary cell walls on the inside of the primary cell walls were observed in both epidermal and inner cells. In addition, the walls of all cells exhibited birefringence. Characteristic thickened secondary cell walls have orientated cellulose microfibrils as well as general secondary cell walls of the tracheary elements. For comparison, these characters were not observed in the petal and bract tissues of Chrysanthemum morifolium. Conclusions Bracts at anthesis are composed of dead cells. Helichrysum bracteatum bracts have characteristic thickened secondary cell walls that have not been observed in the parenchyma of any other flowers or leaves. The cells of the H. bracteatum bract differ from other tissues with secondary cell walls, suggesting that they may be a new cell type. PMID:18436550

  20. Domain wall networks on solitons

    International Nuclear Information System (INIS)

    Sutcliffe, Paul

    2003-01-01

    Domain wall networks on the surface of a soliton are studied in a simple theory. It consists of two complex scalar fields, in 3+1 dimensions, with a global U(1)xZ n symmetry, where n>2. Solutions are computed numerically in which one of the fields forms a Q ball and the other field forms a network of domain walls localized on the surface of the Q ball. Examples are presented in which the domain walls lie along the edges of a spherical polyhedron, forming junctions at its vertices. It is explained why only a small restricted class of polyhedra can arise as domain wall networks

  1. Hard wall - soft wall - vorticity scattering in shear flow

    NARCIS (Netherlands)

    Rienstra, S.W.; Singh, D.K.

    2014-01-01

    An analytically exact solution, for the problem of lowMach number incident vorticity scattering at a hard-soft wall transition, is obtained in the form of Fourier integrals by using theWiener-Hopf method. Harmonic vortical perturbations of inviscid linear shear flow are scattered at the wall

  2. Hard wall - soft wall - vorticity scattering in shear flow

    NARCIS (Netherlands)

    Rienstra, S.W.; Singh, D.K.

    2014-01-01

    An analytically exact solution, for the problem of low Mach number incident vorticity scattering at a hard-soft wall transition, is obtained in the form of Fourier integrals by using the Wiener-Hopf method. Harmonic vortical perturbations of inviscid linear shear flow are scattered at the wall

  3. UWB Propagation through Walls

    Czech Academy of Sciences Publication Activity Database

    Schejbal, V.; Bezoušek, P.; Čermák, D.; NĚMEC, Z.; Fišer, Ondřej; Hájek, M.

    2006-01-01

    Roč. 15, č. 1 (2006), s. 17-24 ISSN 1210-2512 R&D Projects: GA MPO(CZ) FT-TA2/030 Institutional research plan: CEZ:AV0Z30420517 Keywords : Ultra wide band * UWB antennas * UWB propagation * multipath effects Subject RIV: JB - Sensors, Measurment, Regulation

  4. Situation of secondary system piping wearing in overseas nuclear power plants

    International Nuclear Information System (INIS)

    Chiba, Goro

    2005-01-01

    In consideration of secondary system piping rupture accident at Mihama Nuclear Power Station Unit 3 of Kansai Electric Power Company in August 2004, the management system of secondary pipe wall thickness of Japan and foreign countries were investigated. Moreover, the tendency of the secondary piping thinning events on overseas which the Institute of Nuclear Safety System, Inc. (INSS) obtained was analyzed in order to verify the validity of the Japanese management system. Consequently, it was shown that in the U.S., the fault phenomenon of secondary system piping was reported continuously, and there were also many cases of both degradation and penetration of pipe wall. (author)

  5. The "Brick Wall" Graphic Organizer

    Science.gov (United States)

    Matteson, Shirley M.

    2016-01-01

    A brick wall provides a fitting description of what happens when teachers try to teach a concept for which students are unprepared. When students are unsuccessful academically, their foundational knowledge may be missing, incomplete, or incorrect. As a result, students "hit a brick wall," and their academic progress stops because they do…

  6. Control of Wall Mounting Robot

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Pedersen, Rasmus

    2017-01-01

    This paper presents a method for designing controllers for trajectory tracking with actuator constraints. In particular, we consider a joystick-controlled wall mounting robot called WallMo. In contrast to previous works, a model-free approach is taken to the control problem, where the path...

  7. Topological domain walls in helimagnets

    Science.gov (United States)

    Schoenherr, P.; Müller, J.; Köhler, L.; Rosch, A.; Kanazawa, N.; Tokura, Y.; Garst, M.; Meier, D.

    2018-05-01

    Domain walls naturally arise whenever a symmetry is spontaneously broken. They interconnect regions with different realizations of the broken symmetry, promoting structure formation from cosmological length scales to the atomic level1,2. In ferroelectric and ferromagnetic materials, domain walls with unique functionalities emerge, holding great promise for nanoelectronics and spintronics applications3-5. These walls are usually of Ising, Bloch or Néel type and separate homogeneously ordered domains. Here we demonstrate that a wide variety of new domain walls occurs in the presence of spatially modulated domain states. Using magnetic force microscopy and micromagnetic simulations, we show three fundamental classes of domain walls to arise in the near-room-temperature helimagnet iron germanium. In contrast to conventional ferroics, the domain walls exhibit a well-defined inner structure, which—analogous to cholesteric liquid crystals—consists of topological disclination and dislocation defects. Similar to the magnetic skyrmions that form in the same material6,7, the domain walls can carry a finite topological charge, permitting an efficient coupling to spin currents and contributions to a topological Hall effect. Our study establishes a new family of magnetic nano-objects with non-trivial topology, opening the door to innovative device concepts based on helimagnetic domain walls.

  8. Gas from the wall socket

    International Nuclear Information System (INIS)

    Vermeer, B.

    1997-01-01

    A Dutch public utility (Obragas) introduces a new way to supply gas for their household clients in Helmond, Netherlands: the gas wall socket. The use of gas wall sockets must prevent the decrease of the market share for natural gas compared to the market share of electricity for households

  9. Diplopia and Orbital Wall Fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  10. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  11. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  12. Shading Contributes to the Reduction of Stem Mechanical Strength by Decreasing Cell Wall Synthesis in Japonica Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Longmei Wu

    2017-05-01

    Full Text Available Low solar radiation caused by industrial development and solar dimming has become a limitation in crop production in China. It is widely accepted that low solar radiation influences many aspects of plant development, including slender, weak stems and susceptibility to lodging. However, the underlying mechanisms are not well understood. To clarify how low solar radiation affects stem mechanical strength formation and lodging resistance, the japonica rice cultivars Wuyunjing23 (lodging-resistant and W3668 (lodging-susceptible were grown under field conditions with normal light (Control and shading (the incident light was reduced by 60% with a black nylon net. The yield and yield components, plant morphological characteristics, the stem mechanical strength, cell wall components, culm microstructure, gene expression correlated with cellulose and lignin biosynthesis were measured. The results showed that shading significantly reduced grain yield attributed to reduction of spikelets per panicles and grain weight. The stem-breaking strength decreased significantly under shading treatment; consequently, resulting in higher lodging index in rice plant in both varieties, as revealed by decreased by culm diameter, culm wall thickness and increased plant height, gravity center height. Compared with control, cell wall components including non-structural carbohydrate, sucrose, cellulose, and lignin reduced quite higher. With histochemical straining, shading largely reduced lignin deposition in the sclerenchyma cells and vascular bundle cells compared with control, and decreased cellulose deposition in the parenchyma cells of culm tissue in both Wuyunjing23 and W3668. And under shading condition, gene expression involved in secondary cell wall synthesis, OsPAL, OsCOMT, OsCCoAOMT, OsCCR, and OsCAD2, and primary cell wall synthesis, OsCesA1, OsCesA3, and OsCesA8 were decreased significantly. These results suggest that gene expression involved in the reduction of

  13. Shading Contributes to the Reduction of Stem Mechanical Strength by Decreasing Cell Wall Synthesis in Japonica Rice (Oryza sativa L.).

    Science.gov (United States)

    Wu, Longmei; Zhang, Wujun; Ding, Yanfeng; Zhang, Jianwei; Cambula, Elidio D; Weng, Fei; Liu, Zhenghui; Ding, Chengqiang; Tang, She; Chen, Lin; Wang, Shaohua; Li, Ganghua

    2017-01-01

    Low solar radiation caused by industrial development and solar dimming has become a limitation in crop production in China. It is widely accepted that low solar radiation influences many aspects of plant development, including slender, weak stems and susceptibility to lodging. However, the underlying mechanisms are not well understood. To clarify how low solar radiation affects stem mechanical strength formation and lodging resistance, the japonica rice cultivars Wuyunjing23 (lodging-resistant) and W3668 (lodging-susceptible) were grown under field conditions with normal light (Control) and shading (the incident light was reduced by 60%) with a black nylon net. The yield and yield components, plant morphological characteristics, the stem mechanical strength, cell wall components, culm microstructure, gene expression correlated with cellulose and lignin biosynthesis were measured. The results showed that shading significantly reduced grain yield attributed to reduction of spikelets per panicles and grain weight. The stem-breaking strength decreased significantly under shading treatment; consequently, resulting in higher lodging index in rice plant in both varieties, as revealed by decreased by culm diameter, culm wall thickness and increased plant height, gravity center height. Compared with control, cell wall components including non-structural carbohydrate, sucrose, cellulose, and lignin reduced quite higher. With histochemical straining, shading largely reduced lignin deposition in the sclerenchyma cells and vascular bundle cells compared with control, and decreased cellulose deposition in the parenchyma cells of culm tissue in both Wuyunjing23 and W3668. And under shading condition, gene expression involved in secondary cell wall synthesis, OsPAL, OsCOMT, OsCCoAOMT, OsCCR , and OsCAD2 , and primary cell wall synthesis, OsCesA1, OsCesA3 , and OsCesA8 were decreased significantly. These results suggest that gene expression involved in the reduction of lignin and

  14. Anisotropy of domain wall resistance

    Science.gov (United States)

    Viret; Samson; Warin; Marty; Ott; Sondergard; Klein; Fermon

    2000-10-30

    The resistive effect of domain walls in FePd films with perpendicular anisotropy was studied experimentally as a function of field and temperature. The films were grown directly on MgO substrates, which induces an unusual virgin magnetic configuration composed of 60 nm wide parallel stripe domains. This allowed us to carry out the first measurements of the anisotropy of domain wall resistivity in the two configurations of current perpendicular and parallel to the walls. At 18 K, we find 8.2% and 1.3% for the domain wall magnetoresistance normalized to the wall width (8 nm) in these two respective configurations. These values are consistent with the predictions of Levy and Zhang.

  15. Ultrasonography of chest wall lesion

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol Min; Kim, C. H.; Cha, I. H.; Chung, K. B.; Ser, W. H.; Choi, Y. H. [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1989-12-15

    Thirty-one patients with chest wall diseases were studied with ultrasound to evaluate its role in chest wall lesions. There were eight infectious conditions, 9 benign tumors, 11 malignant lesions and 3 miscellaneous cases. Diffuse chest wall thickening with heterogeneous echogenicity and obliteration of subcutaneous fat layer are findings of acute infection. In cases of tuberculous smpyema necessitates, pleural abnormality extended to the chest wall through intercostal space. Benign tumors were well demarcated, except in 4 cases of lipoma/lipomatosis. Malignant lesions showed irregular soft tissue masses, bone destruction, pleural effusion and subcutaneous invasion. Multiple enlarged lymph nodes were also shown. Ultrasound can demonstrate te internal structure, extent, depth and associated findings such as pleural effusion, bone destruction and peripheral lung involvement. Ultrasound is not only safe, non-invasive and an effective diagnostic imaging modality for chest wall disease, but can also guide aspiration or biopsy for pathologic diagnosis

  16. Ultrasonography of chest wall lesion

    International Nuclear Information System (INIS)

    Park, Cheol Min; Kim, C. H.; Cha, I. H.; Chung, K. B.; Ser, W. H.; Choi, Y. H.

    1989-01-01

    Thirty-one patients with chest wall diseases were studied with ultrasound to evaluate its role in chest wall lesions. There were eight infectious conditions, 9 benign tumors, 11 malignant lesions and 3 miscellaneous cases. Diffuse chest wall thickening with heterogeneous echogenicity and obliteration of subcutaneous fat layer are findings of acute infection. In cases of tuberculous smpyema necessitates, pleural abnormality extended to the chest wall through intercostal space. Benign tumors were well demarcated, except in 4 cases of lipoma/lipomatosis. Malignant lesions showed irregular soft tissue masses, bone destruction, pleural effusion and subcutaneous invasion. Multiple enlarged lymph nodes were also shown. Ultrasound can demonstrate te internal structure, extent, depth and associated findings such as pleural effusion, bone destruction and peripheral lung involvement. Ultrasound is not only safe, non-invasive and an effective diagnostic imaging modality for chest wall disease, but can also guide aspiration or biopsy for pathologic diagnosis

  17. Dry wall Kras 2011

    Directory of Open Access Journals (Sweden)

    Domen Zupančič

    2012-01-01

    Full Text Available Despite the modesty of hiska, they show a simple understanding of corbelling technique. One could say they are all examples of human landscape cultivation. Although there is no evident common line when comparing all types of hiska, the cunning eye may observe one shared feature: the positioning of the entrance. More or less all the documented shelters have south or south-western facing entrances. The burja is a cold northerly wind; from the south (Adriatic Sea the winds are warmer. When resting, the setting sun is taken as a sign of the ending of the working day and a reward for the whole day’s efforts. Entrances are the only openings to these structures, and they should serve as well as possible - to watch over the crops, to wait when hunting, to enjoy the calm of evening light, to breathe the sea wind.The syntax of the architectural language of layering stone and shaping the pattern of the landscape remain an inventive realisation of spatial ideas from the past until today. Not only ideas of shaping space - these ideas are basic interventions in the natural habitat which contribute to survival. Culture and an awareness of its values are the origins of local development and reasonable heritage preservation. The next step are tutorial days with workshops on how to build dry stone structures, walls and other stone architecture, as the DSWA organisation in the UK is doing.

  18. Plasma-Wall Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Li, J; Chen, J L [Institute of Plasma Physics, Chinese Academy of Sciences (China); Guo, H Y [Tri Alpha Energy (United States); Institute of Plasma Physics, Chinese Academy of Sciences (China); McCracken, G M [Culham Science Centre, UKAEA, Abingdon (United Kingdom)

    2012-09-15

    The problem of impurities in fusion plasmas has been recognized since the beginning of the fusion programme. Early experiments in glass vacuum vessels released gas from the wall to such an extent that the radiation from the impurities prevented the plasma from being heated above about 50 eV. The radiative power loss is principally due to line radiation from partially stripped ions, which is particularly a problem during the plasma startup phase. Another problem is fuel dilution, which arises because impurity atoms produce many electrons and, for a given plasma pressure, these electrons take the place of fuel particles. Impurities can also lead to disruptions, as a result of edge cooling and consequent current profile modification. The fractional impurity level which radiates 10% of the total thermonuclear power for a 10 keV plasma is 50% for helium, 7% for carbon, and less than 0.1% for molybdenum. Clearly, impurities of low atomic number are a much less serious problem than those of high atomic number. (author)

  19. A role for BELLRINGER in cell wall development is supported by loss-of-function phenotypes

    Directory of Open Access Journals (Sweden)

    Etchells J

    2012-11-01

    Full Text Available Abstract Background Homeodomain transcription factors play critical roles in metazoan development. BELLRINGER (BLR, one such transcription factor, is involved in diverse developmental processes in Arabidopsis, acting in vascular differentiation, phyllotaxy, flower and fruit development. BLR also has a redundant role in meristem maintenance. Cell wall remodelling underpins many of these processes, and BLR has recently been shown to regulate expression of PECTIN METHYL-ESTERASE 5 (PME5, a cell wall modifying enzyme in control of phyllotaxy. We have further explored the role of BLR in plant development by analysing phenotypes and gene expression in a series of plants over-expressing BLR, and generating combinatorial mutants with blr, brevipedicellus (bp, a member of the KNOX1 family of transcription factors that has previously been shown to interact with blr, and the homeodomain transcription factor revoluta (rev, required for radial patterning of the stem. Results Plants over-expressing BLR exhibited a wide range of phenotypes. Some were defective in cell size and demonstrated misregulation of genes predominantly affecting cell wall development. Other lines with more extreme phenotypes failed to generate lateral organs, consistent with BLR repressing transcription in the shoot apex. Cell wall dynamics are also affected in blr mutant plants, and BLR has previously been shown to regulate vascular development in conjunction with BP. We found that when bp and blr were combined with rev, a set of defects was observed that were distinct from those of bp blr lines. In these triple mutants xylem development was most strikingly affected, resulting in an almost complete lack of vessels and xylem parenchyma with secondary thickening. Conclusions Our data support a role for BLR in ordering the shoot apex and, in conjunction with BP and REV, playing a part in determining the composition and organisation of the vascular system. Microarray analysis strongly

  20. Identification of a Classical Mutant in the Industrial Host Aspergillus niger by Systems Genetics: LaeA Is Required for Citric Acid Production and Regulates the Formation of Some Secondary Metabolites

    DEFF Research Database (Denmark)

    Niu, Jing; Arentshorst, Mark; Nair, P. Deepa S.

    2015-01-01

    could provide new insights into the transcriptional control mechanisms related to citric acid production in A. niger. Interestingly, the secondary metabolite profile of a ΔlaeA strain differed from the wild-type strain, showing both decreased and increased metabolite levels, indicating that LaeA is also...

  1. KRE5 Suppression Induces Cell Wall Stress and Alternative ER Stress Response Required for Maintaining Cell Wall Integrity in Candida glabrata

    Science.gov (United States)

    Sasaki, Masato; Ito, Fumie; Aoyama, Toshio; Sato-Okamoto, Michiyo; Takahashi-Nakaguchi, Azusa; Chibana, Hiroji; Shibata, Nobuyuki

    2016-01-01

    The maintenance of cell wall integrity in fungi is required for normal cell growth, division, hyphae formation, and antifungal tolerance. We observed that endoplasmic reticulum stress regulated cell wall integrity in Candida glabrata, which possesses uniquely evolved mechanisms for unfolded protein response mechanisms. Tetracycline-mediated suppression of KRE5, which encodes a predicted UDP-glucose:glycoprotein glucosyltransferase localized in the endoplasmic reticulum, significantly increased cell wall chitin content and decreased cell wall β-1,6-glucan content. KRE5 repression induced endoplasmic reticulum stress-related gene expression and MAP kinase pathway activation, including Slt2p and Hog1p phosphorylation, through the cell wall integrity signaling pathway. Moreover, the calcineurin pathway negatively regulated cell wall integrity, but not the reduction of β-1,6-glucan content. These results indicate that KRE5 is required for maintaining both endoplasmic reticulum homeostasis and cell wall integrity, and that the calcineurin pathway acts as a regulator of chitin-glucan balance in the cell wall and as an alternative mediator of endoplasmic reticulum stress in C. glabrata. PMID:27548283

  2. Ultrasonographic evaluation of masses of the abdominal walls in children

    International Nuclear Information System (INIS)

    Cairo, J.L.B.; Marins, J.L.C.; Prando, A.; Pereira, R.M.

    1988-01-01

    The sonographic features of seven cases of masses of the abdominal wall in children were reviewed. The sonographic manifestations of two cases of lipoma, two cases of abscess (one with intra-abdominal component), one case of lymph angioma, one case of capillary hemangioma and one due to a secondary involvement of a malignant retroperitoneal teratoma are presented. Ultrasound proved to be very useful modality in order to show the topography and the real extent of the disease. (author)

  3. Two Complementary Mechanisms Underpin Cell Wall Patterning during Xylem Vessel Development.

    Science.gov (United States)

    Schneider, Rene; Tang, Lu; Lampugnani, Edwin R; Barkwill, Sarah; Lathe, Rahul; Zhang, Yi; McFarlane, Heather E; Pesquet, Edouard; Niittyla, Totte; Mansfield, Shawn D; Zhou, Yihua; Persson, Staffan

    2017-10-01

    The evolution of the plant vasculature was essential for the emergence of terrestrial life. Xylem vessels are solute-transporting elements in the vasculature that possess secondary wall thickenings deposited in intricate patterns. Evenly dispersed microtubule (MT) bands support the formation of these wall thickenings, but how the MTs direct cell wall synthesis during this process remains largely unknown. Cellulose is the major secondary wall constituent and is synthesized by plasma membrane-localized cellulose synthases (CesAs) whose catalytic activity propels them through the membrane. We show that the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1)/POM2 is necessary to align the secondary wall CesAs and MTs during the initial phase of xylem vessel development in Arabidopsis thaliana and rice ( Oryza sativa ). Surprisingly, these MT-driven patterns successively become imprinted and sufficient to sustain the continued progression of wall thickening in the absence of MTs and CSI1/POM2 function. Hence, two complementary principles underpin wall patterning during xylem vessel development. © 2017 American Society of Plant Biologists. All rights reserved.

  4. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    Science.gov (United States)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  5. Approximal secondary caries lesion progression, a 20-week in situ study

    NARCIS (Netherlands)

    Thomas, R. Z.; Ruben, J. L.; ten Bosch, J. J.; Fidler, V.; Huysmans, M. C. D. N. J. M.

    2007-01-01

    There is no consensus about the definition and progression of outer and wall lesions in secondary caries. In this study we investigated whether lesion progression is influenced by an adjacent composite restoration and whether wall lesions develop at the composite-tooth interface. In order to study

  6. First wall of thermonuclear device

    International Nuclear Information System (INIS)

    Kizawa, Makoto; Koizumi, Makoto; Nishihara, Yoshihiro.

    1990-01-01

    The first wall of a thermonuclear device is constituted with inner wall tiles, e.g. made of graphite and metal substrates for fixing them. However, since the heat expansion coefficient is different between the metal substrates and intermediate metal members, thermal stresses are caused to deteriorate the endurance of the inner wall tiles. In view of the above, low melting metals are disposed at the portion of contact between the inner wall tiles and the metal substrates and, further, a heat pipe structure is incorporated into the metal substrates. Under the thermal load, for example, during operation of the thermonuclear device, the low melting metals at the portion of contact are melted into liquid metals to enhance the state of contact between the inner wall tiles and the metal substrate to reduce the heat resistance and improve the heat conductivity. Even if there is a difference in the heat expansion coefficient between the inner wall tiles and the metal substrates, neither sharing stresses not thermal stresses are caused. Further, since the heat pipe structure is incorporated into the metal substrates, the lateral unevenness of the temperature in the metal substrates can be eliminated. Thus, the durability of the inner wall tiles can be improved. (N.H.)

  7. Shielding wall for thermonuclear device

    International Nuclear Information System (INIS)

    Uchida, Takaho.

    1989-01-01

    This invention concerns shielding walls opposing to plasmas of a thermonuclear device and it is an object thereof to conduct reactor operation with no troubles even if a portion of shielding wall tiles should be damaged. That is, the shielding wall tiles are constituted as a dual layer structure in which the lower base tiles are connected by means of bolts to first walls. Further, the upper surface tiles are bolt-connected to the layer base tiles. In this structure, the plasma thermal loads are directly received by the surface layer tiles and heat is conducted by means of conduction and radiation to the underlying base tiles and the first walls. Even upon occurrence of destruction accidents to the surface layer tiles caused by incident heat or electromagnetic force upon elimination of plasmas, since the underlying base tiles remain as they are, the first walls constituted with stainless steels, etc. are not directly exposed to the plasmas. Accordingly, the integrity of the first walls having cooling channels can be maintained and sputtering intrusion of atoms of high atom number into the plasmas can be prevented. (I.S.)

  8. Photocatalytic surface reactions on indoor wall paint.

    Science.gov (United States)

    Salthammer, T; Fuhrmann, F

    2007-09-15

    The reduction of indoor air pollutants by air cleaning systems has received considerable interest, and a number of techniques are now available. So far, the method of photocatalysis was mainly applied by use of titanium dioxide (TiO2) in flow reactors under UV light of high intensity. Nowadays, indoor wall paints are equipped with modified TiO2 to work as a catalyst under indoor daylight or artificial light. In chamber experiments carried out under indoor related conditions itwas shown thatthe method works for nitrogen dioxide with air exchange and for formaldehyde without air exchange at high concentrations. In further experiments with volatile organic compounds (VOCs), a small effect was found for terpenoids with high kOH rate constants. For other VOCs and carbon monoxide there was no degradation at all or the surface acted as a reversible sink. Secondary emissions from the reaction of paint constituents were observed on exposure to light. From the results it is concluded that recipes of photocatalytic wall paints need to be optimized for better efficiency under indoor conditions.

  9. Implementing Green Walls in Schools.

    Science.gov (United States)

    McCullough, Michael B; Martin, Michael D; Sajady, Mollika A

    2018-01-01

    Numerous studies in applied pedagogical design have shown that, at all educational levels, direct exposure to the natural environment can enhance learning by improving student attention and behaviors. Implementing green walls-a "vertical garden," or "living wall" interior wall that typically includes greenery, a growing medium (soil or substrate) and a water delivery system-provides environmental health benefits, but also provides a practical application within classrooms for minimizing directed attention fatigue in students by connecting them to "outdoor nature" within the indoor environment. Hands-on "project-based" learning is another pedagogical strategy that has proved to be effective across the spectrum of educational levels and across subject areas. Green walls have the potential to inspire critical thinking through a combination of project-based learning strategies and environmental education. The authors have outlined a curriculum involving the implementation of an indoor living wall system within a classroom-learning environment, incorporating project-based learning modules that interact with the wall. In conjunction with the passive health benefits of a green wall, project-based curriculum models can connect students interactively with indoor nature and have the potential to inspire real-world thinking related to science, technology, engineering, art, and mathematics fields within the indoor learning environment. Through a combination of these passive and interactive modes, students are connected to nature in the indoor environment regardless of weather conditions outdoors. Future research direction could include post-construction studies of the effectiveness of project-based curricula related to living walls, and the long-term impacts of implementing green walls in classrooms on school achievement and student behaviors.

  10. Threshold for ion movements in wood cell walls below fiber saturation observed by X-ray fluorescence microscopy (XFM)

    Science.gov (United States)

    Samuel L. Zelinka; Sophie-Charlotte Gleber; Stefan Vogt; Gabriela M. Rodriguez Lopez; Joseph E. Jakes

    2015-01-01

    Diffusion of chemicals and ions through the wood cell wall plays an important role in wood damage mechanisms. In the present work, free diffusion of ions through wood secondary walls and middle lamellae has been investigated as a function of moisture content (MC) and anatomical direction. Various ions (K, Cl, Zn, Cu) were injected into selected regions of 2 ìm thick...

  11. INSOLUBLE HYDROPHOBIN COMPLEXES IN THE WALLS OF SCHIZOPHYLLUM-COMMUNE AND OTHER FILAMENTOUS FUNGI

    NARCIS (Netherlands)

    DEVRIES, OMH; FEKKES, MP; WOSTEN, HAB; WESSELS, JGH

    Two closely related cysteine-rich hydrophobic proteins, Sc3p and Sc4p, of the basidiomycete Schizophyllum commune are developmentally regulated and associated with the walls of aerial hyphae and fruit-body hyphae. They are present in the walls as hot-SDS-insoluble complexes which can be extracted

  12. Economics of abdominal wall reconstruction.

    Science.gov (United States)

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Double wall steam generator tubing

    International Nuclear Information System (INIS)

    Padden, T.R.; Uber, C.F.

    1983-01-01

    Double-walled steam generator tubing for the steam generators of a liquid metal cooled fast breeder reactor prevents sliding between the surfaces due to a mechanical interlock. Forces resulting from differential thermal expansion between the outer tube and the inner tube are insufficient in magnitude to cause shearing of base metal. The interlock is formed by jointly drawing the tubing, with the inside wall of the outer tube being already formed with grooves. The drawing causes the outer wall of the inner tube to form corrugations locking with the grooves. (author)

  14. Plant, cell, and molecular mechanisms of abscisic-acid regulation of stomatal apertures. A new mechanism for the regulation of stomatal-aperture size in intact leaves: Accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba L.

    Energy Technology Data Exchange (ETDEWEB)

    Lu, P.; Outlaw, W.H. Jr.; Smith, B.G.; Freed, G.A.

    1996-12-31

    At various times after pulse labeling Vicia faba L. leaflets with {sup 14}CO{sub 2}, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents whereas those from rinsed peels contained only cytoplastic contents. Sucrose specific radioactivity peaked in palisade cells, 111 GBq{center_dot}mol{sup {minus}1}, at 20 min. In contrast, the {sup 14}C content and sucrose specific radioactivity were very low in guard cells for 20 min, implying little CO{sub 2} incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum sucrose specific radioactivity and a high sucrose influx rate. These and other comparisons implied the presence of (a) multiple sucrose pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived sucrose in guard-cell walls sufficient to diminish stomatal opening by {approximately} 4 {micro}m. Factors expected to enhance sucrose accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic sucrose concentration, which is elevated when mesophyll-sucrose efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal-aperture size by this previously unrecognized mechanism.

  15. Self-regulation processes in the life-course: primary and secondary control / Processos de auto-regulação no curso de vida: controle primário e controle secundário

    Directory of Open Access Journals (Sweden)

    Hilma Tereza Tôrres Khoury

    2009-01-01

    Full Text Available This article discusses relevant concepts of life course perspective which are not very much diffused in Brazil: primary and secondary control. The former refers to efforts to change the environment so that it fits individual's needs. The latter involves efforts to fit in with the environment. The original definitions are presented as a two-process model of control in contrast to one-process models such as learned helplessness. Furthermore, it discusses a conceptual revision, which modified and expanded these constructs as a bi-dimensional model that relates primary and secondary control to the concepts of selection and compensation. In process of arguing about those, suggestions are presented for thinking and expanding the theoretical and conceptual discussion of these constructs.

  16. Use of the omentum in chest-wall reconstruction

    International Nuclear Information System (INIS)

    Fix, R.J.; Vasconez, L.O.

    1989-01-01

    Increased use of the omentum in chest-wall reconstruction has paralleled the refinement of anatomic knowledge and the development of safe mobilization techniques. Important anatomic points are the omental attachments to surrounding structures, the major blood supply from the left and right gastroepiploic vessels, and the collateral circulation via the gastroepiploic arch and Barkow's marginal artery. Mobilization of the omentum to the thorax involves division of its attachments to the transverse colon and separation from the greater curvature to fabricate a bipedicled flap. Most anterior chest wounds and virtually all mediastinal wounds can be covered with the omentum based on both sets of gastroepiploic vessels. The arc of transposition is increased when the omentum is based on a single pedicle, allowing coverage of virtually all chest-wall defects. The final method of increasing flap length involves division of the gastroepiploic arch and reliance on Barkow's marginal artery as collateral circulation to maintain flap viability. With regard to chest-wall reconstruction, we have included the omentum in the armamentarium of flaps used to cover mediastinal wounds. The omentum is our flap of choice for the reconstruction of most radiation injuries of the chest wall. The omentum may also be used to provide protection to visceral anastomoses, vascular conduits, and damaged structures in the chest, as well as to cover defects secondary to tumor excision or trauma. In brief, the omentum has proved to be a most dependable and versatile flap, particularly applicable to chest-wall reconstruction

  17. Plant cell walls to ethanol.

    Science.gov (United States)

    Conversion of plant cell walls to ethanol constitutes generation 2 bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation, and separation. Ultimately, it is desired to combine as man...

  18. Restrained shrinkage of masonry walls

    NARCIS (Netherlands)

    Zijl, G.P.A.G. van; Rots, J.G.

    1998-01-01

    State of the art computational rnechanics, in combination with experimental programmes have a lot to offer in providing insight, characterization of total behaviour and predictive ability of structural masonry. Here numerical research towards rationalizing masonry wall movement joint positioning and

  19. The enrichment secondary market

    International Nuclear Information System (INIS)

    Einbund, D.R.

    1986-01-01

    This paper will addresses two topics: the background to the present status of the enrichment secondary market and the future outlook of the secondary market in enrichment services, and the viability of the nuclear fuel brokerage industry. These two topics are inevitably connected, as most secondary market activity, not only in enrichment but also in natural uranium, has traditionally been conducted with the participation of brokers. Therefore, the author interrelates these topics

  20. Gravity and domain wall problem

    International Nuclear Information System (INIS)

    Rai, B.; Senjanovic, G.

    1992-11-01

    It is well known that the spontaneous breaking of discrete symmetries may lead to conflict with big-bang cosmology. This is due to formation of domain walls which give unacceptable contribution to the energy density of the universe. On the other hand, it is expected that gravity breaks global symmetries explicitly. In this work we propose that this could provide a natural solution to the domain-wall problem. (author). 17 refs

  1. Duct having oscillatory side wall

    Science.gov (United States)

    Sprouse, Kenneth M.

    2018-04-03

    A pump system includes a particulate consolidator pump that has a pump outlet. A duct is coupled to the pump outlet. The duct has a wall that is coupled with an oscillator. The oscillator is operable to oscillate the wall at a controlled frequency. The controlled frequency is selected with respect to breaking static bridging of particulate in the duct due, at least in part, to consolidation of the particulate from a downstream check valve.

  2. Quantitative secondary electron detection

    Science.gov (United States)

    Agrawal, Jyoti; Joy, David C.; Nayak, Subuhadarshi

    2018-05-08

    Quantitative Secondary Electron Detection (QSED) using the array of solid state devices (SSD) based electron-counters enable critical dimension metrology measurements in materials such as semiconductors, nanomaterials, and biological samples (FIG. 3). Methods and devices effect a quantitative detection of secondary electrons with the array of solid state detectors comprising a number of solid state detectors. An array senses the number of secondary electrons with a plurality of solid state detectors, counting the number of secondary electrons with a time to digital converter circuit in counter mode.

  3. Dressed Domain Walls and holography

    International Nuclear Information System (INIS)

    Grisa, Luca; Pujolas, Oriol

    2008-01-01

    The cutoff version of the AdS/CFT correspondence states that the Randall Sundrum scenario is dual to a Conformal Field Theory (CFT) coupled to gravity in four dimensions. The gravitational field produced by relativistic Domain Walls can be exactly solved in both sides of the correspondence, and thus provides one further check of it. We show in the two sides that for the most symmetric case, the wall motion does not lead to particle production of the CFT fields. Still, there are nontrivial effects. Due to the trace anomaly, the CFT effectively renormalizes the Domain Wall tension. On the five dimensional side, the wall is a codimension 2 brane localized on the Randall-Sundrum brane, which pulls the wall in a uniform acceleration. This is perceived from the brane as a Domain Wall with a tension slightly larger than its bare value. In both cases, the deviation from General Relativity appears at nonlinear level in the source, and the leading corrections match to the numerical factors.

  4. Identification of Cell Wall Synthesis Regulatory Genes Controlling Biomass Characteristics and Yield in Rice (Oryza Sativa)

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Zhaohua PEng [Mississippi State University; Ronald, Palmela [UC-Davis; Wang, Guo-Liang [The Ohio State University

    2013-04-26

    synthesis pathway genes are induced by removal of cell wall, some cell wall synthesis apparatus must be shared in both cases. The cell wall re-synthesis mechanism may have broad application because our preliminary assay indicates that the cell wall characteristics are highly different from those produced during cytokinesis. A thorough understanding on the regulation of cell wall re-synthesis may lead to improvement of cell wall characteristics. b) Removal of cell wall results in chromatin decondensation Another interesting observation was that removal of cell wall was associated with substantial chromatin change. Our DNA DAPI stain, chromatin MNase digestion, histone modification proteomics, protein differential expression analysis, and DNA oligo array studies all supported that substantial chromatin change was associated with removal of cell wall treatment. It is still under investigation if the chromatin change is associated with activation of cell wall synthesis genes, in which chromatin remodeling is required. Another possibility is that the cell wall is required for stabilizing the chromatin structure in plant cells. Given that spindle fiber is directly connected with both chromatin structure and cell wall synthesis, it is possible that there is an intrinsic connection between cell wall and chromatin.

  5. Considerations on the design of through-wall anchors

    International Nuclear Information System (INIS)

    Ricklefs, Ulf

    2012-01-01

    Connections to existing buildings are often the most difficult planning challenge for the realization of construction measures in case of piping system replacements in nuclear power plants. This is due to restricted space or limited load reserves of the building structure. Usually the realization of support connections to the existing buildings is achieved by anchor bolts. But in critical cases the preferred alternative solution uses through-wall anchors. Up to now uniform assessment thresholds are not available, no technical guidelines or regulations for construction variants exist. Through-wall anchors allow significantly higher load capacities for tensile and shear loads but require enhanced planning and realization efforts.

  6. CFD modeling of secondary flows in fuel rod bundles

    International Nuclear Information System (INIS)

    Baglietto, Emilio; Ninokata, Hisashi

    2004-01-01

    An optimized non-linear eddy viscosity model is introduced, for calculations of detailed coolant velocity distribution in a tight lattice fuel bundle. The low Reynolds formulation has been optimized based on DNS data for channel flow. The non-linear stress-strain relationship has been modified in the coefficients to model the flow anisotropy, which causes the formation of turbulence driven secondary flows inside the bundle subchannels. Predictions of the model are first compared to experimental measurements of secondary flows in a triangularly arrayed rod bundle with p/d=1.3. Subsequently wall shear stress and velocity predictions are compared with different experimental data for a rod bundle with p/d=1.17. The model shows to be able to correctly reproduce the scale of the secondary motion, and to accurately reproduce both wall shear stress and velocity distributions inside the rod bundle subchannels. (author)

  7. Secondary acute pneumonias

    International Nuclear Information System (INIS)

    Rozenshtraukh, L.C.; Rybakova, N.I.; Vinner, M.G.

    1987-01-01

    Pathological changes, promoting the development of secondary pneumonias, are investigated. To this group belong: blood circulation disturbance in small circle, bronchial passability disturbance, aspiration of liquids, gases and vapors, infections and purulent processes, intoxications, injuries, operative interference. Roetgenologic symptomatics of each secondary acute pneumonia form is presented in detail

  8. Reciprocal Interactions between Cadmium-Induced Cell Wall Responses and Oxidative Stress in Plants

    Directory of Open Access Journals (Sweden)

    Christophe Loix

    2017-10-01

    Full Text Available Cadmium (Cd pollution renders many soils across the world unsuited or unsafe for food- or feed-orientated agriculture. The main mechanism of Cd phytotoxicity is the induction of oxidative stress, amongst others through the depletion of glutathione. Oxidative stress can damage lipids, proteins, and nucleic acids, leading to growth inhibition or even cell death. The plant cell has a variety of tools to defend itself against Cd stress. First and foremost, cell walls might prevent Cd from entering and damaging the protoplast. Both the primary and secondary cell wall have an array of defensive mechanisms that can be adapted to cope with Cd. Pectin, which contains most of the negative charges within the primary cell wall, can sequester Cd very effectively. In the secondary cell wall, lignification can serve to immobilize Cd and create a tougher barrier for entry. Changes in cell wall composition are, however, dependent on nutrients and conversely might affect their uptake. Additionally, the role of ascorbate (AsA as most important apoplastic antioxidant is of considerable interest, due to the fact that oxidative stress is a major mechanism underlying Cd toxicity, and that AsA biosynthesis shares several links with cell wall construction. In this review, modifications of the plant cell wall in response to Cd exposure are discussed. Focus lies on pectin in the primary cell wall, lignification in the secondary cell wall and the importance of AsA in the apoplast. Regarding lignification, we attempt to answer the question whether increased lignification is merely a consequence of Cd toxicity, or rather an elicited defense response. We propose a model for lignification as defense response, with a central role for hydrogen peroxide as substrate and signaling molecule.

  9. Implementing Green Walls in Schools

    Directory of Open Access Journals (Sweden)

    Michael B. McCullough

    2018-06-01

    Full Text Available Numerous studies in applied pedagogical design have shown that, at all educational levels, direct exposure to the natural environment can enhance learning by improving student attention and behaviors. Implementing green walls—a “vertical garden,” or “living wall” interior wall that typically includes greenery, a growing medium (soil or substrate and a water delivery system—provides environmental health benefits, but also provides a practical application within classrooms for minimizing directed attention fatigue in students by connecting them to “outdoor nature” within the indoor environment. Hands-on “project-based” learning is another pedagogical strategy that has proved to be effective across the spectrum of educational levels and across subject areas. Green walls have the potential to inspire critical thinking through a combination of project-based learning strategies and environmental education. The authors have outlined a curriculum involving the implementation of an indoor living wall system within a classroom-learning environment, incorporating project-based learning modules that interact with the wall. In conjunction with the passive health benefits of a green wall, project-based curriculum models can connect students interactively with indoor nature and have the potential to inspire real-world thinking related to science, technology, engineering, art, and mathematics fields within the indoor learning environment. Through a combination of these passive and interactive modes, students are connected to nature in the indoor environment regardless of weather conditions outdoors. Future research direction could include post-construction studies of the effectiveness of project-based curricula related to living walls, and the long-term impacts of implementing green walls in classrooms on school achievement and student behaviors.

  10. Secondary fuel delivery system

    Science.gov (United States)

    Parker, David M.; Cai, Weidong; Garan, Daniel W.; Harris, Arthur J.

    2010-02-23

    A secondary fuel delivery system for delivering a secondary stream of fuel and/or diluent to a secondary combustion zone located in the transition piece of a combustion engine, downstream of the engine primary combustion region is disclosed. The system includes a manifold formed integral to, and surrounding a portion of, the transition piece, a manifold inlet port, and a collection of injection nozzles. A flowsleeve augments fuel/diluent flow velocity and improves the system cooling effectiveness. Passive cooling elements, including effusion cooling holes located within the transition boundary and thermal-stress-dissipating gaps that resist thermal stress accumulation, provide supplemental heat dissipation in key areas. The system delivers a secondary fuel/diluent mixture to a secondary combustion zone located along the length of the transition piece, while reducing the impact of elevated vibration levels found within the transition piece and avoiding the heat dissipation difficulties often associated with traditional vibration reduction methods.

  11. Secondary and tertiary hyperparathyroidism.

    Science.gov (United States)

    Jamal, Sophie A; Miller, Paul D

    2013-01-01

    We reviewed the etiology and management of secondary and tertiary hyperparathyroidism. Secondary hyperparathyroidism is characterized by an increase in parathyroid hormone (PTH) that is appropriate and in response to a stimulus, most commonly low serum calcium. In secondary hyperparathyroidism, the serum calcium is normal and the PTH level is elevated. Tertiary hyperparathyroidism is characterized by excessive secretion of PTH after longstanding secondary hyperparathyroidism, in which hypercalcemia has ensued. Tertiary hyperparathyroidism typically occurs in men and women with chronic kidney disease usually after kidney transplant. The etiology and treatment of secondary hyperparathyroidism is relatively straightforward whereas data on the management of tertiary hyperparathyroidism is limited to a few small trials with short follow-up. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  12. Engineering cell wall synthesis mechanism for enhanced PHB accumulation in E. coli.

    Science.gov (United States)

    Zhang, Xing-Chen; Guo, Yingying; Liu, Xu; Chen, Xin-Guang; Wu, Qiong; Chen, Guo-Qiang

    2018-01-01

    The rigidity of bacterial cell walls synthesized by a complicated pathway limit the cell shapes as coccus, bar or ellipse or even fibers. A less rigid bacterium could be beneficial for intracellular accumulation of poly-3-hydroxybutyrate (PHB) as granular inclusion bodies. To understand how cell rigidity affects PHB accumulation, E. coli cell wall synthesis pathway was reinforced and weakened, respectively. Cell rigidity was achieved by thickening the cell walls via insertion of a constitutive gltA (encoding citrate synthase) promoter in front of a series of cell wall synthesis genes on the chromosome of several E. coli derivatives, resulting in 1.32-1.60 folds increase of Young's modulus in mechanical strength for longer E. coli cells over-expressing fission ring FtsZ protein inhibiting gene sulA. Cell rigidity was weakened by down regulating expressions of ten genes in the cell wall synthesis pathway using CRISPRi, leading to elastic cells with more spaces for PHB accumulation. The regulation on cell wall synthesis changes the cell rigidity: E. coli with thickened cell walls accumulated only 25% PHB while cell wall weakened E. coli produced 93% PHB. Manipulation on cell wall synthesis mechanism adds another possibility to morphology engineering of microorganisms. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  13. Dynamics of strings between walls

    International Nuclear Information System (INIS)

    Eto, Minoru; Fujimori, Toshiaki; Nagashima, Takayuki; Nitta, Muneto; Ohashi, Keisuke; Sakai, Norisuke

    2009-01-01

    Configurations of vortex strings stretched between or ending on domain walls were previously found to be 1/4 Bogomol'nyi-Prasad-Sommerfield (BPS) states in N=2 supersymmetric gauge theories in 3+1 dimensions. Among zero modes of string positions, the center of mass of strings in each region between two adjacent domain walls is shown to be non-normalizable whereas the rests are normalizable. We study dynamics of vortex strings stretched between separated domain walls by using two methods, the moduli space (geodesic) approximation of full 1/4 BPS states and the charged particle approximation for string end points in the wall effective action. In the first method we explicitly obtain the effective Lagrangian in the strong coupling limit, which is written in terms of hypergeometric functions, and find the 90 deg. scattering for head-on collision. In the second method the domain wall effective action is assumed to be U(1) N gauge theory, and we find a good agreement between two methods for well-separated strings.

  14. Modeling of shear wall buildings

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, A K [North Carolina State Univ., Raleigh (USA). Dept. of Civil Engineering

    1984-05-01

    Many nuclear power plant buildings, for example, the auxiliary building, have reinforced concrete shear walls as the primary lateral load resisting system. Typically, these walls have low height to length ratio, often less than unity. Such walls exhibit marked shear lag phenomenon which would affect their bending stiffness and the overall stress distribution in the building. The deformation and the stress distribution in walls have been studied which is applicable to both the short and the tall buildings. The behavior of the wall is divided into two parts: the symmetric flange action and the antisymmetry web action. The latter has two parts: the web shear and the web bending. Appropriate stiffness equations have been derived for all the three actions. These actions can be synthesized to solve any nonlinear cross-section. Two specific problems, that of lateral and torsional loadings of a rectangular box, have been studied. It is found that in short buildings shear lag plays a very important role. Any beam type formulation which either ignores shear lag or includes it in an idealized form is likely to lead to erroneous results. On the other hand a rigidity type approach with some modifications to the standard procedures would yield nearly accurate answers.

  15. Secondary School Admissions Policies in Eastern Africa: Some Regional Issues

    Science.gov (United States)

    Gould, W. T. S.

    1974-01-01

    This discussion considers some regional issues implicit in current procedures regulating admission to secondary education in four countries of Eastern Africa and places these procedures in their general political context. (Author)

  16. The development of a model for dealing with secondary traumatic ...

    African Journals Online (AJOL)

    Jean Damascène Iyamuremye

    tool measuring secondary traumatic stress (Trauma Attachment Belief Scale) in these health workers. ... security, self-capacities and psychological needs as a result of indirect ..... choosing self-harm as an emotion regulation strategy. The.

  17. Secondary pipe rupture at Mihama unit 3

    International Nuclear Information System (INIS)

    Hajime Ito; Takehiko Sera

    2005-01-01

    The secondary system pipe rupture occurred on August 9, 2004, while Mihama unit 3 was operating at the rated thermal power. The rupture took place on the condensate line-A piping between the No.4 LP heater and the deaerator, downstream of an orifice used for measuring the condensate flux. The pipe is made of carbon steel, and normally has 558.8 mm diameter and 10 mm thickness. The pipe wall had thinned to 0.4 mm at the point of minimum thickness. It is estimated that the disturbed flow of water downstream of the orifice caused erosion/corrosion and developed wall thinning, leading to a rupture at the thinnest section under internal pressure, about 1MPa. Observation of the pipe internal surface revealed a scale-like pattern typical in this kind of phenomenon. Eleven workers who were preparing for an annual outage that was to start from August 14 suffered burn injuries, of who five died. Since around 1975, we, Kansai Electric, have been checking pipe wall thickness while focusing on the thinning of carbon steel piping in the secondary system. Summarizing the results from such investigation and reviewing the latest technical knowledge including operating experience from overseas utilities, we compiled the pipe thickness management guideline for PWR secondary pipes, 1990. The pipe section that ruptured at the Mihama unit 3 should have been included within the inspection scopes according to the guideline but was not registered on the inspection list. It had not been corrected for almost thirty years. As the result, this pipe section had not been inspected even once since the beginning of the plant operation, 1976. It seems that the quality assurance and maintenance management had not functioned well regarding the secondary system piping management, although we were responsible for the safety of nuclear power plants as licensee. We will review the secondary system inspection procedure and also improve the pipe thickness management guideline. And also, we would replace

  18. Influence of Carbohydrates on Secondary Metabolism in Fusarium avenaceum

    OpenAIRE

    Jens Laurids Sørensen; Henriette Giese

    2013-01-01

    Fusarium avenaceum is a widespread pathogen of important crops in the temperate climate zones that can produce many bioactive secondary metabolites, including moniliformin, fusarin C, antibiotic Y, 2-amino-14,16-dimethyloctadecan-3-ol (2-AOD-3-ol), chlamydosporol, aurofusarin and enniatins. Here, we examine the production of these secondary metabolites in response to cultivation on different carbon sources in order to gain insight into the regulation and production of secondary metabolites in...

  19. Turbine airfoil with outer wall thickness indicators

    Science.gov (United States)

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  20. Abdominal wall hernia and pregnancy

    DEFF Research Database (Denmark)

    Jensen, K K; Henriksen, N A; Jorgensen, L N

    2015-01-01

    PURPOSE: There is no consensus as to the treatment strategy for abdominal wall hernias in fertile women. This study was undertaken to review the current literature on treatment of abdominal wall hernias in fertile women before or during pregnancy. METHODS: A literature search was undertaken in Pub......Med and Embase in combination with a cross-reference search of eligible papers. RESULTS: We included 31 papers of which 23 were case reports. In fertile women undergoing sutured or mesh repair, pain was described in a few patients during the last trimester of a subsequent pregnancy. Emergency surgery...... of incarcerated hernias in pregnant women, as well as combined hernia repair and cesarean section appears as safe procedures. No major complications were reported following hernia repair before or during pregnancy. The combined procedure of elective cesarean section and abdominal wall hernia repair was reported...

  1. Recovery after abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim

    2017-01-01

    Incisional hernia is a common long-term complication to abdominal surgery, occurring in more than 20% of all patients. Some of these hernias become giant and affect patients in several ways. This patient group often experiences pain, decreased perceived body image, and loss of physical function......, which results in a need for surgical repair of the giant hernia, known as abdominal wall reconstruction. In the current thesis, patients with a giant hernia were examined to achieve a better understanding of their physical and psychological function before and after abdominal wall reconstruction. Study...... was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery...

  2. Teaching secondary mathematics

    CERN Document Server

    Rock, David

    2013-01-01

    Solidly grounded in up-to-date research, theory and technology,?Teaching Secondary Mathematics?is a practical, student-friendly, and popular text for secondary mathematics methods courses. It provides clear and useful approaches for mathematics teachers, and shows how concepts typically found in a secondary mathematics curriculum can be taught in a positive and encouraging way. The thoroughly revised fourth edition combines this pragmatic approach with truly innovative and integrated technology content throughout. Synthesized content between the book and comprehensive companion websi

  3. Chest Wall tumor: combined management

    International Nuclear Information System (INIS)

    Rao Bhaskar, N.

    1997-01-01

    Cancer is relatively rare disease among children and adolescents. The incidence of solid tumors other than CNS is less than 2/100,000. Tumors of the chest wall can arise either from the somatic tissue or ribs. These are rare, so either institutional reviews or multi institutional studies should determine optimal therapeutic management. Of the bony chest wall, Ewing's sarcoma or the family of tumor (peripheral neuro epithelioma, Askin tumor), are the most common. These lesions are lytic and have associated large extra pleural component. This large extra pleural component often necessitates major chest wall resection (3 or more ribs), and when lower ribs are involved, this entails resection of portion of diaphragm. Despite this resection, survival in the early 1970 was 10-20%. Since 1970 multi agent chemotherapy has increased survival rates. of importance, however, is these regimens have caused significant reduction of these extra pleural components so that major chest wall resections have become a rarity. With improved survival and decreased morbidity preoperative chemotherapy followed by surgery is now the accepted modality of treatment. Another major advantage of this regimen is that potential radiation therapy may be obviated. The most common chest wall lesion is rhabdomyosarcoma. In the IRS study of 1620 RMS patients, in 141 (9%) the primary lesion was in the chest wall. these are primarily alveolar histology. when lesions were superficial, wide local excision with supplemental radiation therapy was associated with low morbidity and good overall survival. however, a majority have significant intra- thoracic components. in these circumstances the resectability rate is less than 30% and the survival poor. Other lesions include non rhabdomyosarcomas, eosinophilic granuloma, chondrosarcoma, and osteomyelitis. The management of these lesions varies according to extent, histology, and patient characteristics

  4. Processos de auto-regulação no curso de vida: controle primário e controle secundário Self-regulation processes in the life-course: primary and secondary control

    Directory of Open Access Journals (Sweden)

    Hilma Tereza Tôrres Khoury

    2009-01-01

    Full Text Available Este artigo discute conceitos relevantes à perspectiva do curso de vida, porém pouco difundidos no Brasil: controle primário e controle secundário. O primeiro se refere aos esforços que o indivíduo empreende para adaptar o ambiente às suas necessidades; o segundo, para se adaptar ao ambiente. Apresenta-se a formulação original dos conceitos como modelo de dois processos de controle, em oposição a modelos de processo único, como o do desamparo aprendido. Em seguida, discute-se revisão conceitual que trouxe modificação e ampliação para estes construtos, concebendo-os em um modelo bidimensional que articula controle primário e secundário com os conceitos de seleção e compensação. Nesse processo, apresentam-se contribuições no intuito de estimular a reflexão e expandir a discussão teórico-conceitual que envolve estes construtos.This article discusses relevant concepts of life course perspective which are not very much diffused in Brazil: primary and secondary control. The former refers to efforts to change the environment so that it fits individual's needs. The latter involves efforts to fit in with the environment. The original definitions are presented as a two-process model of control in contrast to one-process models such as learned helplessness. Furthermore, it discusses a conceptual revision, which modified and expanded these constructs as a bi-dimensional model that relates primary and secondary control to the concepts of selection and compensation. In process of arguing about those, suggestions are presented for thinking and expanding the theoretical and conceptual discussion of these constructs.

  5. Shielding walls against ionizing radiation

    International Nuclear Information System (INIS)

    1993-05-01

    Hot-cell shielding walls consist of building blocks made of lead according to DIN 25407 part 1, and of special elements according to DIN 25407 part 2. Alpha-gamma cells can be built using elements for protective contamination boxes according to DIN 25480 part 1. This standards document intends to provide planning engineers, manufacturers, future users and the competent authorities and experts with a basis for the design of hot cells with lead shielding walls and the design of hot-cell equipment. (orig./HP) [de

  6. THESEUS 1, FERONIA and relatives: a family of cell wall-sensing receptor kinases?

    Science.gov (United States)

    Cheung, Alice Y; Wu, Hen-Ming

    2011-12-01

    The plant cell wall provides form and integrity to the cell as well as a dynamic interface between a cell and its environment. Therefore mechanisms capable of policing changes in the cell wall, signaling cellular responses including those that would feedback regulate cell wall properties are expected to play important roles in facilitating growth and ensuring survival. Discoveries in the last few years that the Arabidopsis THESEUS 1 receptor-like kinase (RLK) may function as a sensor for cell wall defects to regulate growth and that its relatives FERONIA and ANXURs regulate pollen tube integrity imply strongly that they play key roles in cell wall-related processes. Furthermore, FERONIA acts as a cell surface regulator for RAC/ROP GTPases and activates production of reactive oxygen species which are, respectively, important molecular switches and mediators for diverse processes. These findings position the THESEUS 1/FERONIA family RLKs as surface regulators and potential cell wall sensors capable of broadly and profoundly impacting cellular pathways in response to diverse signals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Secondary amenorrhea (image)

    Science.gov (United States)

    Secondary amenorrhea is the cessation of menstrual flow for a period of 6 months or more in the absence ... as anxiety can be the root cause of amenorrhea. Treatment can range from behavior modification for excessive ...

  8. Towards secondary fingerprint classification

    CSIR Research Space (South Africa)

    Msiza, IS

    2011-07-01

    Full Text Available an accuracy figure of 76.8%. This small difference between the two figures is indicative of the validity of the proposed secondary classification module. Keywords?fingerprint core; fingerprint delta; primary classifi- cation; secondary classification I..., namely, the fingerprint core and the fingerprint delta. Forensically, a fingerprint core is defined as the innermost turning point where the fingerprint ridges form a loop, while the fingerprint delta is defined as the point where these ridges form a...

  9. Secondary Fire Analysis.

    Science.gov (United States)

    1981-09-01

    Megaton Weapons and Secondary Ignition There are very few well documented data on fires initiated by physical damage (i.e., secondary ignitions). Those data...where significant physical damage to buildings and/or contents can occur. Where this outer bound is located relative to the primary ignition range is...maintenance 7.9 Busline facilities, including shops 3.0 Convalescent homes8 3.1 Hospitals 8.0 Radio and television transmitters Collges and universities

  10. Beam, vacuum and walls, a 3-body interaction

    International Nuclear Information System (INIS)

    Arianer, J.

    2002-11-01

    The interactions between beams of accelerated particles, residual gas and walls involve complex physical processes. In most cases these interactions affect the quality of the vacuum and the value of the pressure. This course reviews all these interactions in a pedagogical and practical way that may be useful for any user of devices involving beams of particles. This document is made up of 6 chapters: 1) basic notions (Maxwell-Boltzmann distribution, kinematics of charged particles, collisions, excitation and ionization), 2) properties of beams (emittance, local effects, and synchrotron radiation), 3) interactions between residual gas and particle beams (Bremsstrahlung radiation, energy loss due to ionization, charge shift of ion beams, photo-absorption and photo-ionization, and slowing-down in a plasma), 4) surface properties (crystal structure, and interaction between surface and the residual gas), 5) interaction between the beam and walls (reflection and diffraction of electrons, secondary emission of electrons, desorption induced by electron and ion impacts, photon production, ion-wall interaction, sputtering, ion penetration, surface ionization and thermal-ionization), and 6) radiation-wall interaction (diffusion, damping, photo-electric effect, desorption induced by photons, pair production and laser-surface interaction). (A.C.)

  11. Simulation of fatigue damagesin secondary truss of crane

    Directory of Open Access Journals (Sweden)

    Eremin Konstantin Ivanovich

    2014-02-01

    Full Text Available Basing on the damaging statistics obtained during the on-site inspections of industrial multi-span building structures with under-crane secondary trusses which have continuous lower plinth, we simulated the scenario of the most likely damage development of under-crane secondary trusses.The first scenario is the development of cracks along the total cross section of plinth. In the process of calculations we defined a real deformation scheme of plinth of under-crane secondary trusses with damage and its stress condition.The second scenario is the destruction of a support or support mounting unit to the lower plinth of under-crane secondary trusses. The destruction of this kind can occur as a result of a crack in a support or as a result of destruction of high-strength fasteners of a support to plinth. We discovered that a system with such damage is geometrically unchanged; there is no possibility of sudden destruction of both the under-crane secondary trusses and the entire building frame.The third scenario is the upper plinth separation from one of the walls of lower plinth of under-crane secondary trusses.The scenario is developed to define the viability of under-crane secondary trusses as a result of cracks in the area of wall junction with the upper shelf of lower plinth, their further development and the appearance of discrete cracks developing into a backbone along the entire span length of under-crane secondary trusses.Based on the calculations of the stress strain state of under-crane secondary trusses with damages in the emergency nature in a separate span of the lower plinth and a truss member, we estimated the viability of structure. The analysis of viability limits makes it possible to find the measures of collapse preventing and avoid possible victims.

  12. Solar Walls for concrete renovation

    DEFF Research Database (Denmark)

    Gramkow, Lotte; Vejen, Niels Kristian; Olsen, Lars

    1996-01-01

    This repport gives a short presentation of three full-scale testing solar walls, the construction including the architectural design, materials and components, transportation and storage of solar enegy, the effect on the construction behind, statics and practical experience.The results of the mea...

  13. Wave Forces on Crown Walls

    DEFF Research Database (Denmark)

    Pedersen, Jan; Burcharth, H. F.

    1993-01-01

    This paper presents some of the results from a large parametric laboratory study including more than 200 long-duration model tests. The study addresses both the wave forces imposed on the breakwater crown wall as well as the performance of the structure in reducing the wave overtopping. The testing...

  14. Fandom and the fourth wall

    Directory of Open Access Journals (Sweden)

    Jenna Kathryn Ballinger

    2014-09-01

    Full Text Available I use the Teen Wolf fandom as an example to examine the ways social media has created a more complicated, nuanced relationship with fans. The collapse of the fourth wall between fans and The Powers That Be can have both positive and negative impacts, depending on the willingness of participants to maintain mutual respect and engage in meaningful dialogue.

  15. Wary Eyes Monitoring Wall Street

    Science.gov (United States)

    Jacobson, Linda

    2008-01-01

    School business officials kept a close watch on the financial markets this week--and on district investment portfolios and teacher-retirement funds--as stock prices gyrated and once-sound institutions got government bailouts or crumbled into bankruptcy. While financial observers said it was too soon to predict how Wall Street's upheaval might…

  16. Shear wall ultimate drift limits

    International Nuclear Information System (INIS)

    Duffey, T.A.; Goldman, A.; Farrar, C.R.

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated

  17. Imaging of chest wall infections

    International Nuclear Information System (INIS)

    Chelli Bouaziz, Mouna; Jelassi, Helmi; Chaabane, Skander; Ladeb, Mohamed Fethi; Ben Miled-Mrad, Khaoula

    2009-01-01

    A wide variety of infections can affect the chest wall including pyogenic, tuberculous, fungal, and some other unusual infections. These potentially life-threatening disorders are frequent especially among immunocompromised patients but often misdiagnosed by physical examination and radiographs. The purpose of this article is to describe the clinical and imaging features of these different chest wall infections according to the different imaging modalities with emphasis on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). The outcome of chest wall infection depends on early diagnosis, severity of the immunosuppression, offending organism, and extent of infection. Because clinical findings and laboratory tests may be not contributive in immunocompromised patients, imaging plays an important role in the early detection and precise assessment of the disease. US, CT, and MRI are all useful: bone destruction is more accurately detected with CT whereas soft tissue involvement are better visualized with US and MRI. CT and US are also used to guide percutaneous biopsy and drainage procedures. MR images are helpful in pre-operative planning of extensive chest wall infections. (orig.)

  18. Designing a Sound Reducing Wall

    Science.gov (United States)

    Erk, Kendra; Lumkes, John; Shambach, Jill; Braile, Larry; Brickler, Anne; Matthys, Anna

    2015-01-01

    Acoustical engineers use their knowledge of sound to design quiet environments (e.g., classrooms and libraries) as well as to design environments that are supposed to be loud (e.g., concert halls and football stadiums). They also design sound barriers, such as the walls along busy roadways that decrease the traffic noise heard by people in…

  19. The Influence of Wall Binders

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    This report is an analysis of the thermal bridge effects that occur in wall binders in masonry buildings. The effects are analyzed using a numerical calculation programme.The results are compared to the values given in the danish standard, DS418....

  20. Chapter 3 Cell Wall Chemistry

    Science.gov (United States)

    Roger M. Rowell; Roger Pettersen; Mandla A. Tshabalala

    2012-01-01

    Wood is best defined as a three-dimensional biopolymer composite composed of an interconnected network of cellulose, hemicelluloses and lignin with minor amounts of extractives, and inorganics. The major chemical component of a living tree is water, but on a dry weight basis, all wood cell walls consist mainly of sugar-based polymers (carbohydrates, 65-75%) that are...

  1. Granular packings with moving side walls

    International Nuclear Information System (INIS)

    Landry, James W.; Grest, Gary Stephen

    2004-01-01

    The effects of movement of the side walls of a confined granular packing are studied by discrete element, molecular dynamics simulations. The dynamical evolution of the stress is studied as a function of wall movement both in the direction of gravity as well as opposite to it. For all wall velocities explored, the stress in the final state of the system after wall movement is fundamentally different from the original state obtained by pouring particles into the container and letting them settle under the influence of gravity. The original packing possesses a hydrostaticlike region at the top of the container which crosses over to a depth-independent stress. As the walls are moved in the direction opposite to gravity, the saturation stress first reaches a minimum value independent of the wall velocity, then increases to a steady-state value dependent on the wall velocity. After wall movement ceases and the packing reaches equilibrium, the stress profile fits the classic Janssen form for high wall velocities, while some deviations remain for low wall velocities. The wall movement greatly increases the number of particle-wall and particle-particle forces at the Coulomb criterion. Varying the wall velocity has only small effects on the particle structure of the final packing so long as the walls travel a similar distance.

  2. A cytochemical and immunocytochemical analysis of the wall labyrinth apparatus in leaf transfer cells in Elodea canadensis.

    Science.gov (United States)

    Ligrone, Roberto; Vaughn, Kevin C; Rascio, Nicoletta

    2011-04-01

    Transfer cells are plant cells specialized in apoplast/symplast transport and characterized by a distinctive wall labyrinth apparatus. The molecular architecture and biochemistry of the labyrinth apparatus are poorly known. The leaf lamina in the aquatic angiosperm Elodea canadensis consists of only two cell layers, with the abaxial cells developing as transfer cells. The present study investigated biochemical properties of wall ingrowths and associated plasmalemma in these cells. Leaves of Elodea were examined by light and electron microscopy and ATPase activity was localized cytochemically. Immunogold electron microscopy was employed to localize carbohydrate epitopes associated with major cell wall polysaccharides and glycoproteins. The plasmalemma associated with the wall labyrinth is strongly enriched in light-dependent ATPase activity. The wall ingrowths and an underlying wall layer share an LM11 epitope probably associated with glucuronoarabinoxylan and a CCRC-M7 epitope typically associated with rhamnogalacturonan I. No labelling was observed with LM10, an antibody that recognizes low-substituted and unsubstituted xylan, a polysaccharide consistently associated with secondary cell walls. The JIM5 and JIM7 epitopes, associated with homogalacturonan with different degrees of methylation, appear to be absent in the wall labyrinth but present in the rest of cell walls. The wall labyrinth apparatus of leaf transfer cells in Elodea is a specialized structure with distinctive biochemical properties. The high level of light-dependent ATPase activity in the plasmalemma lining the wall labyrinth is consistent with a formerly suggested role of leaf transfer cells in enhancing inorganic carbon inflow. The wall labyrinth is a part of the primary cell wall. The discovery that the wall ingrowths in Elodea have an antibody-binding pattern divergent, in part, from that of the rest of cell wall suggests that their carbohydrate composition is modulated in relation to transfer

  3. Bacterial glycobiology: rhamnose-containing cell wall polysaccharides in Gram-positive bacteria.

    Science.gov (United States)

    Mistou, Michel-Yves; Sutcliffe, Iain C; van Sorge, Nina M

    2016-07-01

    The composition of the Gram-positive cell wall is typically described as containing peptidoglycan, proteins and essential secondary cell wall structures called teichoic acids, which comprise approximately half of the cell wall mass. The cell walls of many species within the genera Streptococcus, Enterococcus and Lactococcus contain large amounts of the sugar rhamnose, which is incorporated in cell wall-anchored polysaccharides (CWP) that possibly function as homologues of well-studied wall teichoic acids (WTA). The presence and chemical structure of many rhamnose-containing cell wall polysaccharides (RhaCWP) has sometimes been known for decades. In contrast to WTA, insight into the biosynthesis and functional role of RhaCWP has been lacking. Recent studies in human streptococcal and enterococcal pathogens have highlighted critical roles for these complex polysaccharides in bacterial cell wall architecture and pathogenesis. In this review, we provide an overview of the RhaCWP with regards to their biosynthesis, genetics and biological function in species most relevant to human health. We also briefly discuss how increased knowledge in this field can provide interesting leads for new therapeutic compounds and improve biotechnological applications. © FEMS 2016.

  4. Immobile defects in ferroelastic walls: Wall nucleation at defect sites

    Science.gov (United States)

    He, X.; Salje, E. K. H.; Ding, X.; Sun, J.

    2018-02-01

    Randomly distributed, static defects are enriched in ferroelastic domain walls. The relative concentration of defects in walls, Nd, follows a power law distribution as a function of the total defect concentration C: N d ˜ C α with α = 0.4 . The enrichment Nd/C ranges from ˜50 times when C = 10 ppm to ˜3 times when C = 1000 ppm. The resulting enrichment is due to nucleation at defect sites as observed in large scale MD simulations. The dynamics of domain nucleation and switching is dependent on the defect concentration. Their energy distribution follows the power law with exponents during yield between ɛ ˜ 1.82 and 2.0 when the defect concentration increases. The power law exponent is ɛ ≈ 2.7 in the plastic regime, independent of the defect concentration.

  5. A model for cell wall dissolution in mating yeast cells: polarized secretion and restricted diffusion of cell wall remodeling enzymes induces local dissolution.

    Science.gov (United States)

    Huberman, Lori B; Murray, Andrew W

    2014-01-01

    Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells.

  6. A Model for Cell Wall Dissolution in Mating Yeast Cells: Polarized Secretion and Restricted Diffusion of Cell Wall Remodeling Enzymes Induces Local Dissolution

    Science.gov (United States)

    Huberman, Lori B.; Murray, Andrew W.

    2014-01-01

    Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells. PMID:25329559

  7. Influence of Stationary Crossflow Modulation on Secondary Instability

    Science.gov (United States)

    Choudhari, Meelan M.; Li, Fei; Paredes, Pedro

    2016-01-01

    A likely scenario for swept wing transition on subsonic aircraft with natural laminar flow involves the breakdown of stationary crossflow vortices via high frequency secondary instability. A majority of the prior research on this secondary instability has focused on crossflow vortices with a single dominant spanwise wavelength. This paper investigates the effects of the spanwise modulation of stationary crossflow vortices at a specified wavelength by a subharmonic stationary mode. Secondary instability of the modulated crossflow pattern is studied using planar, partial-differential-equation based eigenvalue analysis. Computations reveal that weak modulation by the first subharmonic of the input stationary mode leads to mode splitting that is particularly obvious for Y-type secondary modes that are driven by the wall-normal shear of the basic state. Thus, for each Y mode corresponding to the fundamental wavelength of results in unmodulated train of crossflow vortices, the modulated flow supports a pair of secondary modes with somewhat different amplification rates. The mode splitting phenomenon suggests that a more complex stationary modulation such as that induced by natural surface roughness would yield a considerably richer spectrum of secondary instability modes. Even modest levels of subharmonic modulation are shown to have a strong effect on the overall amplification of secondary disturbances, particularly the Z-modes driven by the spanwise shear of the basic state. Preliminary computations related to the nonlinear breakdown of these secondary disturbances provide interesting insights into the process of crossflow transition in the presence of the first subharmonic of the dominant stationary vortex.

  8. Incisional subcutaneous endometrioma of the abdominal wall: report of two cases; Endometriose sous cutanee sur cicatrice de la paroi abdominale anterieure. A propos de deux observations

    Energy Technology Data Exchange (ETDEWEB)

    Merran, S.; Karila-Cohen, P. [Federation Mutualiste Parisienne, Dept. d' Imagerie Medicale, 75 - Paris (France)

    2004-04-01

    Endometriosis occurs in up to 15% of menstruating women. Abdominal wall involvement is rare and always secondary to an invasive procedure. The authors report the imaging and clinical findings of two patients with subcutaneous endometrioma following cesarean section. (author)

  9. Secondary metabolites from Ganoderma.

    Science.gov (United States)

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

    2015-06-01

    Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Essential oil of Litsea salicifolia Roxb. ex Wall : a new report from Assam, India

    NARCIS (Netherlands)

    Choudhury, M.; Choudhury, S.N.; Ghosh, A.C.; Leclercq, P.A.

    1997-01-01

    Litsea salicijolia Roxb. ex Wall. (Dighloti in Assamese) is a secondary food plant for the muga silkworm (Antheraea assama Ww.). Experiments conducted at the Regional Research Laboratory, Jorhat, Assam, India, indicated the presence ofan essential oil in the leaves of this plant species, which has

  11. PRE-CAST WALL PRODUCTS MADE FROM LIGHTWEIGHT CONCRETE FOR ENCLOSING STRUCTURES OF BUILDINGS

    Directory of Open Access Journals (Sweden)

    M. R. Hadgiev

    2014-01-01

    Full Text Available The paper is devoted to the actual problem waste dismantling of buildings and structures in the form of brick waste with reception the secondary fine and coarse aggregate and concrete based on them for the manufacture of small-piece wall products. 

  12. Numerical Analysis of Carbon Fiber Reinforced Plastic (CFRP) Shear Walls and Steel Strips under Cyclic Loads Using Finite Element Method

    OpenAIRE

    Askarizadeh, N.; Mohammadizadeh, M. R.

    2017-01-01

    Reinforced concrete shear walls are the main elements of resistance against lateral loads in reinforced concrete structures. These walls should not only provide sufficient resistance but also provide sufficient ductility in order to avoid brittle fracture, particularly under strong seismic loads. However, many reinforced concrete shear walls need to be stabilized and reinforced due to various reasons such as changes in requirements of seismic regulations, weaknesses in design and execution, p...

  13. A Novel Distributed Secondary Coordination Control Approach for Islanded Microgrids

    DEFF Research Database (Denmark)

    Lu, Xiaoqing; Yu, Xinghuo; Lai, Jingang

    2018-01-01

    This paper develops a new distributed secondary cooperative control scheme to coordinate distributed generators (DGs) in islanded microgrids (MGs). A finite time frequency regulation strategy containing a consensus-based distributed active power regulator is presented, which can not only guarantee...

  14. Regulating the Regulator

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-26

    The article reports on a challenge to the UK electricity regulator to defend his record by the Coalition for Fair Electricity Regulation (COFFER). The challenge centres on whether the obligation for the regional electric companies (REC) to purchase power from the cheapest source is being enforced. This is related to the wider issue of whether the REC's support of combined-cycle gas turbine (CCGT) is economic. COFFER considers that uneconomic gas-fired power plants are being allowed to displace economic coal-fired stations. Aspects discussed include the background to the dispute and the costs of CCGT and coal fired power generation. 1 fig., 1 tab.

  15. Brick walls on the brane

    International Nuclear Information System (INIS)

    Medved, A J M

    2002-01-01

    The so-called 'brick-wall model' is a semiclassical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein-Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior study invoked a simplifying assumption (which we avoid) that cannot be adequately justified

  16. Domain walls at finite temperature

    International Nuclear Information System (INIS)

    Carvalho, C.A. de; Marques, G.C.; Silva, A.J. da; Ventura, I.

    1983-08-01

    It is suggested that the phase transition of lambda phi 4 theory as a function of temperature coincides with the spontaneous appearance of domain walls. Based on one-loop calculations, T sub(c) = 4M/√ lambda is estimated as the temperature for these domains to because energetically favored, to be compared with T sub(c) = 4.9M/√ lambda from effective potential calculations (which are performed directly in the broken phase). Domain walls, as well as other Types of fluctuations, disorder the system above T sub(c), leading to =0. The critical exponent for the specific heat above T sub(c) is computed; and α=2/3 + 0 (√ lambda) is obtained. (Author) [pt

  17. Fast wall of thermonuclear device

    International Nuclear Information System (INIS)

    Kitamura, Kazunori.

    1990-01-01

    A protruding molten metal reservoir is disposed to a sealing vessel embedded in the armour tile of fast walls, and molten metal of low melting point such as tin, lead or alloy thereof is filled in the sealing vessel. The volume of the molten metal reservoir is determined such that the surface level of the molten metal is kept within the molten metal reservoir even when the sealed low melting point metal is solidified at room temperature. When the temperature is lowered during plasma interruption period and the sealed low melting molten metal is solidified to reduce the volume, most of the molten metal reservoir regioin constitutes a vacuum gap. However, the inner wall of the sealing vessel other than the molten metal reservior region can be kept into contact with the sealed metal. Accordingly, the temperature and the sublimation loss of the armour tile can be kept low even upon plasma heat application. (I.N.)

  18. Thin walls in regions with vacuum energy

    Energy Technology Data Exchange (ETDEWEB)

    Garfinkle, D [Florida Univ., Gainesville, FL (USA). Dept. of Physics; Vuille, C [Embry-Riddle Aeronautical Univ., Prescott, AZ (USA). Dept. of Math/Physical Science

    1989-12-01

    The motion of a thin wall is treated in the case where the regions on either side of the wall have vacuum energy. This treatment generalises previous results involving domain walls in vacuum and also previous results involving the properties of false vacuum bubbles. The equation of state for a domain wall is{tau} = {sigma} where {tau} is the tension in the wall and {sigma} is the energy density. We consider the motion of a more general class of walls having equation of state {tau}{Gamma}{sigma} with 0{le}{Gamma}{le}1. Spherically symmetric and planar symmetric walls are examined. We also find the global structure of the wall spacetime. (author).

  19. The DEMO wall load challenge

    Czech Academy of Sciences Publication Activity Database

    Wenninger, R.; Albanese, R.; Ambrosino, R.; Arbeiter, F.; Aubert, J.; Bachmann, C.; Barbato, L.; Barrett, T.; Beckers, M.; Biel, W.; Boccaccini, L.; Carralero, D.; Coster, D.; Eich, T.; Fasoli, A.; Federici, G.; Firdaouss, M.; Graves, J.; Horáček, Jan; Kovari, M.; Lanthaler, S.; Loschiavo, V.; Lowry, C.; Lux, H.; Maddaluno, G.; Maviglia, F.; Mitteau, R.; Neu, R.; Pfefferle, D.; Schmid, K.; Siccinio, M.; Sieglin, B.; Silva, C.; Snicker, A.; Subba, F.; Varje, J.; Zohm, H.

    2017-01-01

    Roč. 57, č. 4 (2017), č. článku 046002. ISSN 0029-5515 EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 Keywords : DEMO * power loads * first wall Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.307, year: 2016 http://iopscience.iop.org/article/10.1088/1741-4326/aa4fb4

  20. Gas target with thin wall

    International Nuclear Information System (INIS)

    Korenchenko, A.S.; Korenchenko, S.M.; Kravchuk, N.P.; Filippov, A.I.; Fursov, A.P.

    1992-01-01

    The technology of targets manufacture with thin wall diameter 100 mm and lengthwise 700 mm from composition kevlar + epoxy resin is described. The test's results on pressure and vacuum are reported. The created targets are supposed to be used on the installation ARES for an investigation of muons and pions interactions with light nuclei and rare pions decay 'on flying'. 5 refs.; 2 figs.; 2 tabs

  1. Physics of resistive wall modes

    International Nuclear Information System (INIS)

    Igochine, V.

    2012-01-01

    The advanced tokamak regime is a promising candidate for steady-state tokamak operation which is desirable for a fusion reactor. This regime is characterized by a high bootstrap current fraction and a flat or reversed safety factor profile, which leads to operation close to the pressure limit. At this limit, an external kink mode becomes unstable. This external kink is converted into the slowly growing resistive wall mode (RWM) by the presence of a conducting wall. Reduction of the growth rate allows one to act on the mode and to stabilize it. There are two main factors which determine the stability of the RWM. The first factor comes from external magnetic perturbations (error fields, resistive wall, feedback coils, etc). This part of RWM physics is the same for tokamaks and reversed field pinch configurations. The physics of this interaction is relatively well understood and based on classical electrodynamics. The second ingredient of RWM physics is the interaction of the mode with plasma flow and fast particles. These interactions are particularly important for tokamaks, which have higher plasma flow and stronger trapped particle effects. The influence of the fast particles will also be increasingly more important in ITER and DEMO which will have a large fraction of fusion born alpha particles. These interactions have kinetic origins which make the computations challenging since not only particles influence the mode, but also the mode acts on the particles. Correct prediction of the ‘plasma–RWM’ interaction is an important ingredient which has to be combined with external field's influence (resistive wall, error fields and feedback) to make reliable predictions for RWM behaviour in tokamaks. All these issues are reviewed in this paper. (special topic)

  2. Electron arc therapy: chest wall irradiation of breast cancer patients

    International Nuclear Information System (INIS)

    McNeely, L.K.; Jacobson, G.M.; Leavitt, D.D.; Stewart, J.R.

    1988-01-01

    From 1980 to October 1985 we treated 45 breast cancer patients with electron arc therapy. This technique was used in situations where optimal treatment with fixed photon or electron beams was technically difficult: long scars, recurrent tumor extending across midline or to the posterior thorax, or marked variation in depth of target tissue. Forty-four patients were treated following mastectomy: 35 electively because of high risk of local failure, and 9 following local recurrence. One patient with advanced local regional disease was treated primarily. The target volume boundaries on the chest wall were defined by a foam lined cerrobend cast which rested on the patient during treatment, functioning as a tertiary collimator. A variable width secondary collimator was used to account for changes in the radius of the thorax from superior to inferior border. All patients had computerized tomography performed to determine Internal Mammary Chain depth and chest wall thickness. Electron energies were selected based on these thicknesses and often variable energies over different segments of the arc were used. The chest wall and regional node areas were irradiated to 45 Gy-50 Gy in 5-6 weeks by this technique. The supraclavicular and upper axillary nodes were treated by a direct anterior photon field abutted to the superior edge of the electron arc field. Follow-up is from 10-73 months with a median of 50 months. No major complications were observed. Acute and late effects and local control are comparable to standard chest wall irradiation. The disadvantages of this technique are that the preparation of the tertiary field defining cast and CT treatment planning are labor intensive and expensive. The advantage is that for specific clinical situations large areas of chest wall with marked topographical variation can be optimally, homogeneously irradiated while sparing normal uninvolved tissues

  3. Identification of a classical mutant in the industrial host Aspergillus niger by systems genetics: LaeA is required for citric acid production and regulates the formation of some secondary metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing; Arentshorst, Mark; Nair, Deepa; Dai, Ziyu; Baker, Scott E.; Frisvad, Jens; Nielsen, Kristian F.; Punt, Peter J.; Ram, Arthur F.

    2016-01-11

    Rapid acidification of the culture medium by the production of organic acids and the production of acid-induced proteases are key characteristics of the filamentous fungus Aspergillus niger. The D15 mutant of A. niger is non-acidifying mutant and used often for the expression of recombinant proteins in A. niger, because of its reduced production of extracellular proteases under non-acidic conditions. In this study, the D15 mutant is characterized in detail. Strongly reduced levels of citric and oxalic acid were observed in the D15 mutant both in shake flask cultures and in controlled batch cultivations. To identify the mutation in the D15 mutant, we successfully combined high-throughput sequencing (Illumina) with bulk segregant analysis. Because of the lack of a sexual cycle for A. niger, the parasexual cycle was used to generate a pool of segregants. From the 52 single nucleotide polymorphisms (SNPs) between the parental strains, three SNPs were homozygous in the genomic DNA of pool of segregants. These three SNPs mapped to all the right arm of chromosome II, indicating that this region contains the genetic locus affecting the phenotype related to acid production. Of the three SNPs, one mutation resulted in a missense mutation in the gene encoding the A. niger homologue of the A. nidulans methyltransferase gene laeA. Complementation analysis of the original mutant with the laeA gene and targeted disruption of laeA further confirmed that LaeA is involved in citric acid production in A. niger lab (N402) and citric acid production strains (ATCC 11414). Analysis of the secondary metabolite (SM) profile of the laeA mutants indicate that LaeA is required for the production of several SMs (asperrubrol, atromentin and JBIR86), but deletion of laeA also resulted in the presence of SMs (aspernigrin A/B and BMS-192548) that were not detected in the wild-type strain. The levels of ten other SMs were not strongly affected as a result of laeA deletion indicating that only a

  4. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  5. Alternative to domain wall fermions

    International Nuclear Information System (INIS)

    Neuberger, H.

    2002-01-01

    An alternative to commonly used domain wall fermions is presented. Some rigorous bounds on the condition number of the associated linear problem are derived. On the basis of these bounds and some experimentation it is argued that domain wall fermions will in general be associated with a condition number that is of the same order of magnitude as the product of the condition number of the linear problem in the physical dimensions by the inverse bare quark mass. Thus, the computational cost of implementing true domain wall fermions using a single conjugate gradient algorithm is of the same order of magnitude as that of implementing the overlap Dirac operator directly using two nested conjugate gradient algorithms. At a cost of about a factor of two in operation count it is possible to make the memory usage of direct implementations of the overlap Dirac operator independent of the accuracy of the approximation to the sign function and of the same order as that of standard Wilson fermions

  6. Method of constructing shielding wall

    International Nuclear Information System (INIS)

    Nagao, Tetsuya.

    1990-01-01

    For instance, surfaces of lead particles each formed into a sphere of about 0.5 to 0.3 mm grain size are coated with a coating material of a synthetic resin comprising a polymeric material such as teflon. Subsequently, the floated lead particle are kneaded with concrete materials and then poured into a molding die by way of a hose. After coagulation, the molding die is removed to complete shielding walls in which lead particles are scattered substantially at an equal distance. In this way, since the lead particles are mixed into the shielding walls, shielding effects can be improved by so much as the lead particles are mixed, thereby enabling to reduce the thickness of the shielding walls. Further, since the lead particles are coated with the coating material, the lead particles are insulated from the concrete materials, thereby enabling to prevent the corrosion of the lead particles. Furthermore, since the lead particles and the concrete materials can be transported with ease, operation labors can be reduced. (T.M.)

  7. Flooding Effect on Earth Walls

    Directory of Open Access Journals (Sweden)

    Meysam Banimahd

    2010-12-01

    Full Text Available Earth building is a sustainable, environmentally friendly and economical method of construction that has been used worldwide for many centuries. For the past three decades, earth has seen a revival as a building material for a modern construction method due to its benefits in terms of low carbon content, low cost and energy involved during construction, as well as the fact that it is a sustainable technology of building. Climate change is influencing precipitation levels and patterns around the world, and as a consequence, flood risk is increasing rapidly. When flooding occurs, earth buildings are exposed to water by submersion, causing an increase in the degree of saturation of the earth structures and therefore a decrease of the suction between particles. This study investigated the effect of cycles of flooding (consecutive events of flooding followed by dry periods on earth walls. A series of characterization tests were carried out to obtain the physical and mechanical properties of the studied earth material. In a second stage, Flooding Simulation Tests (FST were performed to explore the earth walls’ response to repeated flooding events. The results obtained for the tested earth wall/samples with reinforced material (straw reveal hydraulic hysteresis when wall/samples are subject to cycles of wetting and drying.

  8. A numerical study of external building walls containing phase change materials (PCM)

    International Nuclear Information System (INIS)

    Izquierdo-Barrientos, M.A.; Belmonte, J.F.; Rodríguez-Sánchez, D.; Molina, A.E.; Almendros-Ibáñez, J.A.

    2012-01-01

    Phase Change Materials (PCMs) have been receiving increased attention, due to their capacity to store large amounts of thermal energy in narrow temperature ranges. This property makes them ideal for passive heat storage in the envelopes of buildings. To study the influence of PCMs in external building walls, a one-dimensional transient heat transfer model has been developed and solved numerically using a finite difference technique. Different external building wall configurations were analyzed for a typical building wall by varying the location of the PCM layer, the orientation of the wall, the ambient conditions and the phase transition temperature of the PCM. The integration of a PCM layer into a building wall diminished the amplitude of the instantaneous heat flux through the wall when the melting temperature of the PCM was properly selected according to the season and wall orientation. Conversely, the results of the work show that there is no significant reduction in the total heat lost during winter regardless of the wall orientation or PCM transition temperature. Higher differences were observed in the heat gained during the summer period, due to the elevated solar radiation fluxes. The high thermal inertia of the wall implies that the inclusion of a PCM layer increases the thermal load during the day while decreasing the thermal load during the night. - Highlights: ► A comparative simulation of a building wall with and without PCMs has been conducted. ► PCM is selected according with the season, the wall orientation and the melting temperature. ► PCM in a building wall help to diminish the internal air temperature swings and to regulate the heat transfer.

  9. Surface segregation in binary alloy first wall candidate materials

    International Nuclear Information System (INIS)

    Gruen, D.M.; Krauss, A.R.; Mendelsohn, M.H.; Susman, S.; Argonne National Lab., IL

    1982-01-01

    We have been studying the conditions necessary to produce a self-sustaining stable lithium monolayer on a metal substrate as a means of creating a low-Z film which sputters primarily as secondary ions. It is expected that because of the toroidal field, secondary ions originating at the first wall will be returned and contribute little to the plasma impurity influx. Aluminum and copper have, because of their high thermal conductivity and low induced radioactivity, been proposed as first wall candidate materials. The mechanical properties of the pure metals are very poorly suited to structural applications and an alloy must be used to obtain adequate hardness and tensile strength. In the case of aluminum, mechanical properties suitable for aircraft manufacture are obtained by the addition of a few at% Li. In order to investigate alloys of a similar nature as candidate structural materials for fusion machines we have prepared samples of Li-doped aluminum using both a pyro-metallurgical and a vapor-diffusion technique. The sputtering properties and surface composition have been studied as a function of sample temperature and heating time, and ion beam mass. The erosion rate and secondary ion yield of both the sputtered Al and Li have been monitored by secondary ion mass spectroscopy and Auger analysis providing information on surface segregation, depth composition profiles, and diffusion rates. The surface composition ahd lithium depth profiles are compared with previously obtained computational results based on a regular solution model of segregation, while the partial sputtering yields of Al and Li are compared with results obtained with a modified version of the TRIM computer program. (orig.)

  10. Upgrade of the Proton West secondary beamline

    International Nuclear Information System (INIS)

    Spiegel, L.

    1989-01-01

    As originally designed and operated, protons entering PW6 were steered by a series of EPB dipoles into a single interaction length beryllium target, some 43 feet from the enclosure wall. Ensuing secondary beams, either p + /π + or p - /π - , were collected by a string of quadrupoles following the target, steered westward, away from the Proton Center line, through PW6 and PW7, and ultimately focussed on experiment production targets located within the large PW8 hall. Around the Spring of 1988 it was decided to upgrade the existing Proton West secondary beamline to allow for transport of a primary proton beam, anticipated to be either 800 or 900 GeV/c, through PW8. This upgrade project, which is now nearing completion, was largely motivated by the then recent approval of E-771, a hadronic beauty production experiment located in PW8. E-771 represents the third in a series of experiments for the large-acceptance dimuon spectrometer presently located at the end of the Proton West beamline. This Technical Memo is a summary of the upgrade --- an explanation of the underlying strategy and a documentation of the final locations of the secondary beamline elements. 6 refs., 2 figs., 2 tabs

  11. Gas Enrichment at Liquid-Wall Interfaces

    NARCIS (Netherlands)

    Dammer, S.M.; Lohse, Detlef

    2006-01-01

    Molecular dynamics simulations of Lennard-Jones systems are performed to study the effects of dissolved gas on liquid-wall and liquid-gas interfaces. Gas enrichment at walls, which for hydrophobic walls can exceed more than 2 orders of magnitude when compared to the gas density in the bulk liquid,

  12. Theory of topological edges and domain walls

    NARCIS (Netherlands)

    Bais, F.A.; Slingerland, J.K.; Haaker, S.M.

    2009-01-01

    We investigate domain walls between topologically ordered phases in two spatial dimensions. We present a method which allows for the determination of the superselection sectors of excitations of such walls and which leads to a unified description of the kinematics of a wall and the two phases to

  13. The cell wall of Fusarium oxysporum

    NARCIS (Netherlands)

    Schoffelmeer, EAM; Klis, FM; Sietsma, JH; Cornelissen, BJC

    1999-01-01

    Sugar analysis of isolated cell walls from three formae speciales of Fusarium oxysporum showed that they contained not only glucose and (N-acetyl)-glucosamine, but also mannose, galactose, and uronic acids, presumably originating from cell wall glycoproteins. Cell wall glycoproteins accounted for

  14. To detect anomalies in diaphragm walls

    NARCIS (Netherlands)

    Spruit, R.

    2015-01-01

    Diaphragm walls are potentially ideal retaining walls for deep excavations in densely built-up areas, as they cause no vibrations during their construction and provide structural elements with high strength and stiffness. In the recent past, however, several projects using diaphragm walls as soil

  15. Making Your Music Word Wall Work

    Science.gov (United States)

    Leonhardt, Angela

    2011-01-01

    This article looks at what a word wall is and its use in the music classroom. The author outlines steps for creation of a word wall within the music classroom as well as the importance of such a resource. The author encourages the creation and consistent use of the word wall as leading to the development of stronger musicians and also independent,…

  16. Genome-Wide Association Mapping for Cell Wall Composition and Properties in Temperate Grasses

    DEFF Research Database (Denmark)

    Bellucci, Andrea

    with a wide range of chemical bounds. At present the interest in plant cell wall is growing due to the possibility to convert ligno-cellulosic biomass (e.g. agricultural residues) into bioethanol but also for the benefits to human health of some cell wall constituents found in cereals, in particular beta......-glucans. Plant cell wall biosynthesis is regulated by a large number of genes and regulatory factors but very few of these are known and characterized. This PhD project aimed to the identification of putative candidate genes involved in plant cell wall composition and properties using a genome wide (GWAS......) approach. The species investigate were wheat, barley and B. distachyon, considered a model plant for temperate cereals. Agronomical traits as yield and plant height were also included in the analysis along with cell wall composition and saccharification properties. Several marker-trait associations were...

  17. Wall envelopes in office buildings: design trend and implications on cooling load of buildings

    International Nuclear Information System (INIS)

    Ibrahim, N.; Ahmed, A.Z.; Ahmed, S.S.

    2006-01-01

    The wall envelope is a vital element of a building especially to a high rise building where its wall to building volume ratio is higher compared to other building forms. As well as a means of architectural expression, the wall envelope protects and regulates the indoor environment. In recent years there have been many applications of glass products and cladding systems in high-rise buildings built in Kuala Lumpur. This paper describes a recent research and survey on wall envelope designs adopted in 33 high-rise office buildings built in the central business district of Kuala Lumpur since 1990. This research adopts component design analysis to identify dominant trends on wall envelope design for the surveyed buildings. The paper seeks to discourse the implications of this design trend on energy consumption of high-rise office buildings in the country

  18. Dynamics of secondary forests

    NARCIS (Netherlands)

    Breugel, van M.

    2007-01-01

    The succession of tropical secondary forests on abandoned agricultural fields has been studied since long, most often by comparing stands of different age since abandonment. These so-called chronosequence studies have yielded much insight in general patterns of succession and the constraints and

  19. Two secondary drops

    Indian Academy of Sciences (India)

    Figure shows formation of two secondary drops of unequal size and their merger. The process is same as the earlier process until t= 0.039 Tc with necking occurring at two places, one at the bottom of the column and the other at the middle. The necking at the middle of the liquid column is due to Raleigh instability.

  20. [Primary and secondary encopresis].

    Science.gov (United States)

    Lang-Langer, Ellen

    2007-01-01

    While the difficulty of the child to part with its faeces in primary encopresis is linked to the incapability to experience the object as separated and independent from himself, secondary encopresis is a progressed psychical state of development. In this case we have to deal with regression caused by conflict. Two case-studies show clearly the differences.

  1. [Secondary thrombotic microangiopathies].

    Science.gov (United States)

    Coppo, P

    2017-11-01

    Thrombotic microangiopathies (TMA) are termed secondary when associated to a specific context favouring their occurrence. They encompass mainly TMA associated with pregnancy, allogeneic hematopoietic stem cell transplantation, cancer, drugs, or HIV infection. Secondary TMA represent a heterogeneous group of diseases which clinical presentation largely depends on the associated context. It is therefore mandatory to recognize these conditions since they have a significant impact in TMA management and prognosis. A successful management still represents a challenge in secondary TMA. Significant progresses have been made in the understanding of pregnancy-associated TMA, allowing an improvement of prognosis; on the opposite, other forms of secondary TMA such as hematopoietic stem cell transplantation-associated TMA or TMA associated with chemotherapy remain of dismal prognosis. A better understanding of pathophysiology in these forms of TMA, in association with a more empirical approach through the use of new therapeutic agents that can also help in the understanding on new mechanisms a posteriori, should improve their prognosis. The preliminary encouraging results reported with complement blockers in this field could represent a convincing example. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  2. Secondary coolant purification system

    International Nuclear Information System (INIS)

    Stiteler, F.Z.; Donohue, J.P.

    1978-01-01

    The present invention combines the attributes of volatile chemical addition, continuous blowdown, and full flow condensate demineralization. During normal plant operation (defined as no primary to secondary leakage) condensate from the condenser is pumped through a full flow condensate demineralizer system by the condensate pumps. Volatile chemical additions are made. Dissolved and suspended solids are removed in the condensate polishers by ion exchange and/or filtration. At the same time a continuous blowdown of approximately 1 percent of the main steaming rate of the steam generators is maintained. Radiation detectors monitor the secondary coolant. If these monitors indicate no primary to secondary leakage, the blowdown is cooled and returned directly to the condensate pump discharge. If one of the radiation monitors should indicate a primary to secondary leak, when the temperature of the effluent exiting from the blowdown heat exchanger is compatible with the resin specifications of the ion exchangers, the bypass valve causes the blowdown flow to pass through the blowdown ion exchangers

  3. Abdominal wall reconstruction for large incisional hernia restores expiratory lung function

    DEFF Research Database (Denmark)

    Jensen, Kristian K; Backer, Vibeke; Jorgensen, Lars N

    2017-01-01

    BACKGROUND: Respiratory complications secondary to intermittent intra-abdominal hypertension and/or atelectasis are common after abdominal wall reconstruction for large incisional hernias. It is unknown if the respiratory function of this patient group is affected long term or impairs activities...... of daily living. We hypothesized that abdominal wall reconstruction for large incisional hernia would not lead to improved, long-term pulmonary function or respiratory quality of life. METHODS: Eighteen patients undergoing open abdominal wall reconstruction with mesh for a large incisional hernia...... (horizontal fascial defect width >10 cm) were compared with 18 patients with an intact abdominal wall who underwent colorectal resection. Patients were examined pre- and 1-year postoperatively. Examined measures included forced vital capacity, forced expiratory volume in first second, peak expiratory flow...

  4. Emotional Intelligence of Self Regulated Learners

    Science.gov (United States)

    Rathore, Ami

    2018-01-01

    The study was conducted on self regulated learners of senior secondary school. The main objectives of the study were to find out significant dimensions of emotional intelligence held by self regulated learners. To compare the emotional intelligence dimensions of self regulated learners, in terms of subject and gender. To find out the relationship…

  5. Market, Regulation, Market, Regulation

    DEFF Research Database (Denmark)

    Frankel, Christian; Galland, Jean-Pierre

    2015-01-01

    barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had......This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...

  6. Fragility assessment method of Concrete Wall Subjected to Impact Loading

    International Nuclear Information System (INIS)

    Hahm, Daegi; Shin, Sang Shup; Choi, In-Kil

    2014-01-01

    These studies have been aimed to verify and ensure the safety of the targeted walls and structures especially in the viewpoint of the deterministic approach. However, recently, the regulation and the assessment of the safety of the nuclear power plants (NPPs) against to an aircraft impact are strongly encouraged to adopt a probabilistic approach, i.e., the probabilistic risk assessment of an aircraft impact. In Korea, research to develop aircraft impact risk quantification technology was initiated in 2012 by Korea Atomic Energy Research Institute (KAERI). In this paper, for the one example of the probabilistic safety assessment approach, a method to estimate the failure probability and fragility of concrete wall subjected to impact loading caused by missiles or engine parts of aircrafts will be introduced. This method and the corresponding results will be used for the total technical roadmap and the procedure to assess the aircraft impact risk (Fig.1). A method and corresponding results of the estimation of the failure probability and fragility for a concrete wall subjected to impact loadings caused by missiles or engine parts of aircrafts was introduced. The detailed information of the target concrete wall in NPP, and the example aircraft engine model is considered safeguard information (SGI), and is not contained in this paper

  7. Laminar boundary layer near the rotating end wall of a confined vortex

    Science.gov (United States)

    Shakespeare, W. J.; Levy, E. K.

    1982-06-01

    The results of an experimental and theoretical investigation of the fluid mechanics in a confined vortex are discussed with particular emphasis on behavior away from the axis of symmetry and near the end walls. The vortex is generated in a rotating cylindrical chamber with an exit opening in one end. Both end walls rotate. For the range of flow rates and swirl ratios (S between 1 and 5) of interest here, the flow field far from the end walls behaves as inviscid and irrotational; and the end wall boundary layers are thin and laminar. Measurements and calculations of tangential and radial velocity in the end wall region show the development of a secondary flow resulting in a strong velocity 'overshoot' in the radial component. Results illustrating the nature of the velocity variations on the end walls are presented; and it is shown that the mass flow rate through the end wall boundary layers, while only a small fraction of the total flow, increases with increasing swirl and with decreasing total flow rate through the chamber.

  8. Detection of wood cell wall porosity using small carbohydrate molecules and confocal fluorescence microscopy.

    Science.gov (United States)

    Donaldson, L A; Kroese, H W; Hill, S J; Franich, R A

    2015-09-01

    A novel approach to nanoscale detection of cell wall porosity using confocal fluorescence microscopy is described. Infiltration of cell walls with a range of nitrophenyl-substituted carbohydrates of different molecular weights was assessed by measuring changes in the intensity of lignin fluorescence, in response to the quenching effect of the 4-nitrophenyl group. The following carbohydrates were used in order of increasing molecular weight; 4-nitrophenyl β-D-glucopyrano-side (monosaccharide), 4-nitrophenyl β-D-lactopyranoside (disaccharide), 2-chloro-4-nitrophenyl β-D-maltotrioside (trisaccharide), and 4-nitrophenyl α-D-maltopentaoside (pentasaccharide). This technique was used to compare cell wall porosity in wood which had been dewatered to 40% moisture content using supercritical CO2, where cell walls remain fully hydrated, with kiln dried wood equilibrated to 12% moisture content. Infiltration of cell walls as measured by fluorescence quenching, was found to decrease with increasing molecular weight, with the pentasaccharide being significantly excluded compared to the monosaccharide. Porosity experiments were performed on blocks and sections to assess differences in cell wall accessibility. Dewatered and kiln dried wood infiltrated as blocks showed similar results, but greater infiltration was achieved by using sections, indicating that not all pores were easily accessible by infiltration from the lumen surface. In wood blocks infiltrated with 4-nitrophenyl α-D-maltopentaoside, quenching of the secondary wall was quite variable, especially in kiln dried wood, indicating limited connectivity of pores accessible from the lumen surface. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  9. Mechanism of bubble detachment from vibrating walls

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongjun; Park, Jun Kwon, E-mail: junkeun@postech.ac.kr; Kang, Kwan Hyoung [Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Kang, In Seok [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of)

    2013-11-15

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  10. Near-wall serpentine cooled turbine airfoil

    Science.gov (United States)

    Lee, Ching-Pang

    2013-09-17

    A serpentine coolant flow path (54A-54G) formed by inner walls (50, 52) in a cavity (49) between pressure and suction side walls (22, 24) of a turbine airfoil (20A). A coolant flow (58) enters (56) an end of the airfoil, flows into a span-wise channel (54A), then flows forward (54B) over the inner surface of the pressure side wall, then turns behind the leading edge (26), and flows back along a forward part of the suction side wall, then follows a loop (54E) forward and back around an inner wall (52), then flows along an intermediate part of the suction side wall, then flows into an aft channel (54G) between the pressure and suction side walls, then exits the trailing edge (28). This provides cooling matched to the heating topography of the airfoil, minimizes differential thermal expansion, revives the coolant, and minimizes the flow volume needed.

  11. The origin of 'Great Walls'

    International Nuclear Information System (INIS)

    Shandarin, Sergei F.

    2009-01-01

    A new semi-analytical model that explains the formation and sizes of the 'great walls' - the largest structures observed in the universe is suggested. Although the basis of the model is the Zel'dovich approximation it has been used in a new way very different from the previous studies. Instead of traditional approach that evaluates the nonlinear density field it has been utilized for identification of the regions in Lagrangian space that after the mapping to real or redshift space (depending on the kind of structure is studied) end up in the regions where shell-crossing occurs. The set of these regions in Lagrangian space form the progenitor of the structure and after the mapping it determines the pattern of the structure in real or redshift space. The particle trajectories have crossed in such regions and the mapping is no longer unique there. The progenitor after mapping makes only one stream in the multi-stream flow regions therefore it does not comprise all the mass. Nevertheless, it approximately retains the shape of the structure. The progenitor of the structure in real space is determined by the linear density field along with two non-Gaussian fields derived from the initial potential. Its shape in Eulerian space is also affected by the displacement field. The progenitor of the structure in redshift space also depends on these fields but in addition it is strongly affected by two anisotropic fields that determine the pattern of great walls as well as their huge sizes. All the fields used in the mappings are derived from the linear potential smoothed at the current scale of nonlinearity which is R nl = 2.7 h −1 Mpc for the adopted parameters of the ΛCDM universe normalized to σ 8 = 0.8. The model predicts the existence of walls with sizes significantly greater than 500 h −1 Mpc that may be found in sufficiently large redshift surveys

  12. First Wall and Operational Diagnostics

    International Nuclear Information System (INIS)

    Lasnier, C; Allen, S; Boedo, J; Groth, M; Brooks, N; McLean, A; LaBombard, B; Sharpe, J; Skinner, C; Whyte, D; Rudakov, D; West, W; Wong, C

    2006-01-01

    In this chapter we review numerous diagnostics capable of measurements at or near the first wall, many of which contribute information useful for safe operation of a tokamak. There are sections discussing infrared cameras, visible and VUV cameras, pressure gauges and RGAs, Langmuir probes, thermocouples, and erosion and deposition measurements by insertable probes and quartz microbalance. Also discussed are dust measurements by electrostatic detectors, laser scattering, visible and IR cameras, and manual collection of samples after machine opening. In each case the diagnostic is discussed with a view toward application to a burning plasma machine such as ITER

  13. Moving walls and geometric phases

    Energy Technology Data Exchange (ETDEWEB)

    Facchi, Paolo, E-mail: paolo.facchi@ba.infn.it [Dipartimento di Fisica and MECENAS, Università di Bari, I-70126 Bari (Italy); INFN, Sezione di Bari, I-70126 Bari (Italy); Garnero, Giancarlo, E-mail: giancarlo.garnero@uniba.it [Dipartimento di Fisica and MECENAS, Università di Bari, I-70126 Bari (Italy); INFN, Sezione di Bari, I-70126 Bari (Italy); Marmo, Giuseppe [Dipartimento di Scienze Fisiche and MECENAS, Università di Napoli “Federico II”, I-80126 Napoli (Italy); INFN, Sezione di Napoli, I-80126 Napoli (Italy); Samuel, Joseph [Raman Research Institute, 560080 Bangalore (India)

    2016-09-15

    We unveil the existence of a non-trivial Berry phase associated to the dynamics of a quantum particle in a one dimensional box with moving walls. It is shown that a suitable choice of boundary conditions has to be made in order to preserve unitarity. For these boundary conditions we compute explicitly the geometric phase two-form on the parameter space. The unboundedness of the Hamiltonian describing the system leads to a natural prescription of renormalization for divergent contributions arising from the boundary.

  14. Another Concrete In the Wall

    OpenAIRE

    Meric, Asli Duru

    2015-01-01

    concrete has a memory. It stores the construction sequences. It shows what it is made of and how it is made. The texture of the formwork, the color difference of the pours, and the shadows of the metal ties combine to layer the beauty of concrete. The aim of this study is to explore the instruments of a concrete surface in order to enhance this multi-sensory experience. This study began with the design of a concrete wall and evolved into the design of a single-family home. MARCH

  15. Methodology for first wall design

    International Nuclear Information System (INIS)

    Galambos, J.D.; Conner, D.L.; Goranson, P.L.; Lousteau, D.C.; Williamson, D.E.; Nelson, B.E.; Davis, F.C.

    1993-01-01

    An analytic parametric scoping tool has been developed for application to first wall (FW) design problems. Both thermal and disruption force effects are considered. For the high heat flux and high disruption load conditions expected in the International Thermonuclear Experimental Reactor (ITER) device, Vanadium alloy and dispersion-strengthened copper offer the best stress margins using a somewhat flattened plasma-facing configuration. Ferritic steels also appear to have an acceptable stress margin, whereas the conventional stainless steel 316 does not appear feasible. If a full semicircle shape FW is required, only the Vanadium and ferritic steel alloy have acceptable solutions

  16. The Wall On Gladstone Avenue

    Directory of Open Access Journals (Sweden)

    Pina MARCHESE

    2012-12-01

    Full Text Available "Since the house is on fire, Let us warm ourselves..." (Calabrian Proverb It all began in the village. We would wake up with the sun, we would rest our laboured bodies underneath the moon. Gli vecchi (old folks often told us: "In the end, all that will remain is our story. Nothing else really matters." This article "The Wall On Gladstone Avenue" will take you into a life of duality and how immigrants "press-on" to acquire knowledge and manifest meaning in a new land Canada.

  17. Thoracic Wall Necrotizing Fasccitiss in a Neonate: a Case Report

    Directory of Open Access Journals (Sweden)

    Serdar Onat

    2010-09-01

    Full Text Available Necrotizing fasciitis (NF is a rapidly progressive and potentially life-threatening infection of superficial fascia and subcutaneous tissue. Thoracic wall is one of the rarest locations for NF. Broadspectrum antibiotics receiving, early surgical debridement, and skin grafting are life saving in NF. We report a 7-day-old female neonate who had left sided thoracic wall NF. She had undergone extensive surgical debridement within 4 hours of hospital admission, and reconstruction of skin defect by split-thickness skin grafting later. Early diagnosis is important, as prompt surgical debridement offers the best chance for survival. Early and extensive surgical debridement is a widely accepted clinical approach and the mainstay of effective treatment. The goals of surgical intervention are to remove all necrotic tissues, and to help control the progression of NF. Reconstruction of skin defects should be performed by early split-thickness skin grafting like our patient or primary closure. Because early wound resurfacing prevents fluid, electrolyte, and protein loss from the wound site, and decreases secondary infection. Although chest wall NF is rare in neonates, it is a rapidly spreading, highly lethal infection. A high index of suspicion, early diagnosis, and aggressive approach are essential to its successful treatment.

  18. Secondary hypertension in adults.

    Science.gov (United States)

    Puar, Troy Hai Kiat; Mok, Yingjuan; Debajyoti, Roy; Khoo, Joan; How, Choon How; Ng, Alvin Kok Heong

    2016-05-01

    Secondary hypertension occurs in a significant proportion of adult patients (~10%). In young patients, renal causes (glomerulonephritis) and coarctation of the aorta should be considered. In older patients, primary aldosteronism, obstructive sleep apnoea and renal artery stenosis are more prevalent than previously thought. Primary aldosteronism can be screened by taking morning aldosterone and renin levels, and should be considered in patients with severe, resistant or hypokalaemia-associated hypertension. Symptoms of obstructive sleep apnoea should be sought. Worsening of renal function after starting an angiotensin-converting enzyme inhibitor suggests the possibility of renal artery stenosis. Recognition, diagnosis and treatment of secondary causes of hypertension lead to good clinical outcomes and the possible reversal of end-organ damage, in addition to blood pressure control. As most patients with hypertension are managed at the primary care level, it is important for primary care physicians to recognise these conditions and refer patients appropriately. Copyright: © Singapore Medical Association.

  19. Secondary combined suicide pact.

    Science.gov (United States)

    Jayanth, S H; Girish Chandra, Y P; Hugar, Basappa S; Kainoor, Sunilkumar

    2014-03-01

    This article reports a combined suicide pact, where in a young couple; a 26 year old male and a 20 year old female committed suicide by using two methods. The couple had resorted to hanging and self-immolation to prevent failure of single method alone. In secondary combined suicides, several other methods of suicide are tried after the first method chosen has failed. It is primary combined suicide only when two or more methods are used simultaneously. Both types of combined suicide by one individual is well reported in the literature whereas the same by two persons together is rare. In this report, the deceased were disappointed lovers, poor and the family members were against their marriage. The investigation of scene, methods employed to commit suicide, autopsy findings and the interview with their relatives altogether suggested that it was a secondary combined suicide pact. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  20. THE SECONDARY EXTINCTION CORRECTION

    Energy Technology Data Exchange (ETDEWEB)

    Zachariasen, W. H.

    1963-03-15

    It is shown that Darwin's formula for the secondary extinction correction, which has been universally accepted and extensively used, contains an appreciable error in the x-ray diffraction case. The correct formula is derived. As a first order correction for secondary extinction, Darwin showed that one should use an effective absorption coefficient mu + gQ where an unpolarized incident beam is presumed. The new derivation shows that the effective absorption coefficient is mu + 2gQ(1 + cos/sup 4/2 theta )/(1 plus or minus cos/sup 2/2 theta )/s up 2/, which gives mu + gQ at theta =0 deg and theta = 90 deg , but mu + 2gQ at theta = 45 deg . Darwin's theory remains valid when applied to neutron diffraction. (auth)

  1. Secondary Breast Augmentation.

    Science.gov (United States)

    Brown, Mitchell H; Somogyi, Ron B; Aggarwal, Shagun

    2016-07-01

    After studying this article, the participant should be able to: 1. Assess common clinical problems in the secondary breast augmentation patient. 2. Describe a treatment plan to correct the most common complications of breast augmentation. 3. Provide surgical and nonsurgical options for managing complications of breast augmentation. 4. Decrease the incidence of future complications through accurate assessment, preoperative planning, and precise surgical technique. Breast augmentation has been increasing steadily in popularity over the past three decades. Many of these patients present with secondary problems or complications following their primary breast augmentation. Two of the most common complications are capsular contracture and implant malposition. Familiarity and comfort with the assessment and management of these complications is necessary for all plastic surgeons. An up-to-date understanding of current devices and techniques may decrease the need to manage future complications from the current cohort of breast augmentation patients.

  2. Lipopolysaccharide (LPS) stimulation of fungal secondary metabolism

    Science.gov (United States)

    Khalil, Zeinab G.; Kalansuriya, Pabasara; Capon, Robert J.

    2014-01-01

    We report on a preliminary investigation of the use the Gram-negative bacterial cell wall constituent lipopolysaccharide (LPS) as a natural chemical cue to stimulate and alter the expression of fungal secondary metabolism. Integrated high-throughput micro-cultivation and micro-analysis methods determined that 6 of 40 (15%) of fungi tested responded to an optimal exposure to LPS (0.6 ng/mL) by activating, enhancing or accelerating secondary metabolite production. To explore the possible mechanisms behind this effect, we employed light and fluorescent microscopy in conjunction with a nitric oxide (NO)-sensitive fluorescent dye and an NO scavenger to provide evidence that LPS stimulation of fungal secondary metabolism coincided with LPS activation of NO. Several case studies demonstrated that LPS stimulation can be scaled from single microplate well (1.5 mL) to preparative (>400 mL) scale cultures. For example, LPS treatment of Penicillium sp. (ACM-4616) enhanced pseurotin A and activated pseurotin A1 and pseurotin A2 biosynthesis, whereas LPS treatment of Aspergillus sp. (CMB-M81F) substantially accelerated and enhanced the biosynthesis of shornephine A and a series of biosynthetically related ardeemins and activated production of neoasterriquinone. As an indication of broader potential, we provide evidence that cultures of Penicillium sp. (CMB-TF0411), Aspergillus niger (ACM-4993F), Rhizopus oryzae (ACM-165F) and Thanatephorus cucumeris (ACM-194F) were responsive to LPS stimulation, the latter two examples being particular noteworthy as neither are known to produce secondary metabolites. Our results encourage the view that LPS stimulation can be used as a valuable tool to expand the molecular discovery potential of fungal strains that either have been exhaustively studied by or are unresponsive to traditional culture methodology. PMID:25379339

  3. Secondary victims of rape

    DEFF Research Database (Denmark)

    Christiansen, Dorte Mølgaard; Bak, Rikke; Elklit, Ask

    2012-01-01

    secondary victims, including family members, partners, and friends of male and female rape victims. We found that many respondents found it difficult to support the PV and that their relationship with the PV was often affected by the assault. Furthermore, the sample showed significant levels...... of social support for the respondent, and feeling let down by others. The respondents were generally interested in friend-, family-, and partner-focused interventions, particularly in receiving education about how best to support a rape victim...

  4. A computational approach for inferring the cell wall properties that govern guard cell dynamics.

    Science.gov (United States)

    Woolfenden, Hugh C; Bourdais, Gildas; Kopischke, Michaela; Miedes, Eva; Molina, Antonio; Robatzek, Silke; Morris, Richard J

    2017-10-01

    Guard cells dynamically adjust their shape in order to regulate photosynthetic gas exchange, respiration rates and defend against pathogen entry. Cell shape changes are determined by the interplay of cell wall material properties and turgor pressure. To investigate this relationship between turgor pressure, cell wall properties and cell shape, we focused on kidney-shaped stomata and developed a biomechanical model of a guard cell pair. Treating the cell wall as a composite of the pectin-rich cell wall matrix embedded with cellulose microfibrils, we show that strong, circumferentially oriented fibres are critical for opening. We find that the opening dynamics are dictated by the mechanical stress response of the cell wall matrix, and as the turgor rises, the pectinaceous matrix stiffens. We validate these predictions with stomatal opening experiments in selected Arabidopsis cell wall mutants. Thus, using a computational framework that combines a 3D biomechanical model with parameter optimization, we demonstrate how to exploit subtle shape changes to infer cell wall material properties. Our findings reveal that proper stomatal dynamics are built on two key properties of the cell wall, namely anisotropy in the form of hoop reinforcement and strain stiffening. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd and Society for Experimental Biology.

  5. Regulation of cellulose synthesis in response to stress.

    Science.gov (United States)

    Kesten, Christopher; Menna, Alexandra; Sánchez-Rodríguez, Clara

    2017-12-01

    The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Unusual manifestations of secondary urothelial carcinoma

    Directory of Open Access Journals (Sweden)

    Chaohui Lisa Zhao

    2016-03-01

    Full Text Available High-grade papillary urothelial carcinoma regularly invades the bladder wall, adjacent prostate, seminal vesicles, ureters, vagina, rectum, retroperitoneum, and regional lymph nodes. In advanced stages, it may disseminate to the liver, lungs, and bone marrow. On rare occasions, unusual metastatic foci like skin have been reported. The incidence of urothelial carcinoma has increased with associated rise in variants of urothelial carcinoma and unusual metastatic foci. It is imperative that urologists and pathologists are aware of the unusual variants and unusual metastatic locations to expedite the diagnostic process. Hereby we report an unusual case of secondary involvement of spinal nerve by conventional urothelial carcinoma. Also a second case of rhabdoid variant of urothelial carcinoma showing synchronous involvement of bladder and subcutaneous tissue of upper extremity is presented.

  7. Anterior chest wall examination reviewed

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Anterior chest wall involvement is not infrequently observed within inflammatory arthropaties, particularly if one considers seronegative spondiloarthritides and SAPHO syndrome. Physical examination is unreliable and conventional X-rays analysis is an unsatisfactory tool during diagnostic work-up of this region. Scintigraphic techniques yield informations both on the activity and on the anatomical extent of the disease while computerized tomography visualize the elementary lesions, such as erosions, which characterize the process. Moreover, when available, magnetic resonance imaging couple the ability to finely visualize such lesions with the possibility to show early alterations and to characterize the “activity” of the disease, presenting itself as a powerful tool both for diagnosis and follow-up. This review briefly shows the applications of imaging techniques for the evaluation of the anterior chest wall focusing on what has been done in the SAPHO syndrome which can be considered prototypical for this regional involvement since it is the osteo-articular target mainly affected by the disease.

  8. Reactor wall in thermonuclear device

    International Nuclear Information System (INIS)

    Shibui, Masanao.

    1988-01-01

    Purpose: To always monitor the life of armours in reactor walls and automatically shutdown the reactor if it should be operated in excess of the limit of use. Constitution: Monitoring material of lower melting point than armours (for example beryllium pellets) as one of the reactor wall constituents of a thermonuclear device are embedded in a region leaving the thickness corresponding to the allowable abrasion of the armour. In this structure, if the armours are abrased due to particle loads of a plasma and the abrasion exceeds a predetermined allowable level, the monitoring material is exposed to the plasma and melted and evaporated. Since this can be detected by impurity monitors disposed in the reactor, it is possible to recognize the limit for the working life of the armours. If the thermonuclear reactor should be operated accidentally exceeding the life of the armours, since a great amount of the monitoring materials have been evaporated, they flow into the plasma to increase the plasma radiation loss thereby automatically eliminate the plasma. (K.M.)

  9. Tritium issues in plasma wall interactions

    International Nuclear Information System (INIS)

    Tanabe, T.

    2009-01-01

    In order to establish a D-T fusion reactor as an energy source, it is not enough to have a DT burning plasma, and economical conversion of fusion energy to electricity and/or heat, a large enough margin of tritium breeding and tritium safety must be simultaneously achieved. In particular, handling of huge amount of tritium needs a significant effort to ensure that the radiation dose of radiological workers and of the public is below the limits specified by the International Commission on Radiological Protection. For the safety reasons, tritium in a reactor will be limited to only a few kg orders in weight, with radioactivity up to 10 17 Bq. Since public exposure to tritium is regulated at a level as tiny as a few Bq/cm 2 , tritium must be strictly confined in a reactor system with accountancy of an order of pg (pico-gram). Generally qualitative analysis with the accuracy of more than 3 orders of magnitude is hardly possible. We are facing to lots of safety concerns in the handling of huge amounts of radioactive tritium as a fuel and to be bred in a blanket. In addition, tritium resources are very limited. Not only for the safety reason but also for the saving of tritium resources, tritium retention in a reactor must be kept as small as possible. In the present tokamaks, however, hydrogen retention is significantly large, i.e. more than 20% of fueled hydrogen is continuously piled up in the vacuum vessel, which must not be allowed in a reactor. After the introduction of tritium as a hydrogen radioisotope, this lecture will present tritium issues in plasma wall interactions, in particular, fueling, retention and recovering, considering the handling of large amounts of tritium, i.e. confinement, leakage, contamination, permeation, regulations and tritium accountancy. Progress in overcoming such problems will be also presented. This document is made of the slides of the presentation. (author)

  10. Characteristics and generation of secondary jets and secondary gigantic jets

    Science.gov (United States)

    Lee, Li-Jou; Huang, Sung-Ming; Chou, Jung-Kung; Kuo, Cheng-Ling; Chen, Alfred B.; Su, Han-Tzong; Hsu, Rue-Rou; Frey, Harald U.; Takahashi, Yukihiro; Lee, Lou-Chuang

    2012-06-01

    Secondary transient luminous events (TLEs) recorded by the ISUAL-FORMOSAT2 mission can either be secondary jets or secondary gigantic jets (GJs), depending on their terminal altitudes. The secondary jets emerge from the cloud top beneath the preceding sprites and extend upward to the base of the sprites at ˜50 km. The secondary jets likely are negative electric discharges with vertically straight luminous columns, morphologically resembling the trailing jet of the type-I GJs. The number of luminous columns in a secondary jet seems to be affected by the size of the effective capacitor plate formed near the base of the preceding sprites and the charge distribution left behind by the sprite-inducing positive cloud-to-ground discharges. The secondary GJs originate from the cloud top under the shielding area of the preceding sprites, and develop upward to reach the lower ionosphere at ˜90 km. The observed morphology of the secondary GJs can either be the curvy shifted secondary GJs extending outside the region occupied by the preceding sprites or the straight pop-through secondary GJs developing through the center of the preceding circular sprites. A key factor in determining the terminal height of the secondary TLEs appears to be the local ionosphere boundary height that established by the preceding sprites. The abundance and the distribution of the negative charge in the thundercloud following the sprite-inducing positive cloud-to-ground discharges may play important role in the generation of the secondary TLEs.

  11. Immersion Refractometry of Isolated Bacterial Cell Walls

    Science.gov (United States)

    Marquis, Robert E.

    1973-01-01

    Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid

  12. Biosynthesis of secondary metabolites in sugarcane

    Directory of Open Access Journals (Sweden)

    S.C. França

    2001-12-01

    Full Text Available A set of genes related to secondary metabolism was extracted from the sugarcane expressed sequence tag (SUCEST database and was used to investigate both the gene expression pattern of key enzymes regulating the main biosynthetic secondary metabolism pathways and the major classes of metabolites involved in the response of sugarcane to environmental and developmental cues. The SUCEST database was constructed with tissues in different physiological conditions which had been collected under varied situation of environmental stress. This database allows researchers to identify and characterize the expressed genes of a wide range of putative enzymes able to catalyze steps in the phenylpropanoid, isoprenoid and other pathways of the special metabolic mechanisms involved in the response of sugarcane to environmental changes. Our results show that sugarcane cDNAs encoded putative ultra-violet induced sesquiterpene cyclases (SC; chalcone synthase (CHS, the first enzyme in the pathway branch for flavonoid biosynthesis; isoflavone synthase (IFS, involved in plant defense and root nodulation; isoflavone reductase (IFR, a key enzyme in phenylpropanoid phytoalexin biosynthesis; and caffeic acid-O-methyltransferase, a key enzyme in the biosynthesis of lignin cell wall precursors. High levels of CHS transcripts from plantlets infected with Herbaspirillum rubri or Gluconacetobacter diazotroficans suggests that agents of biotic stress can elicit flavonoid biosynthesis in sugarcane. From this data we have predicted the profile of isoprenoid and phenylpropanoid metabolism in sugarcane and pointed the branches of secondary metabolism activated during tissue-specific stages of development and the adaptive response of sugarcane to agents of biotic and abiotic stress, although our assignment of enzyme function should be confirmed by careful biochemical and genetic supporting evidence.Este trabalho foi realizado com os objetivos de gerar uma coleção de genes

  13. Osteocytes Mechanosensing in NASA Rotating Wall Bioreactor

    Science.gov (United States)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocyte cells are the most abundant (90%) yet least understood bone cell type in the human body. Osteocytes are theorized to be the mechanosensors and transducers of mechanical load for bones, yet the biological mechanism of this action remains elusive. However, recent discoveries in osteocyte cell biology have shed light on their importance as key mechanosensing cells regulating bone remodeling and phosphate homeostasis. The aim of this project was to characterize gene expression patterns and protein levels following exposure of MLO-Y4, a very well characterized murine osteocyte-like cell line, to simulated microgravity using the NASA Rotating Wall Vessel (RWV) Bioreactor. To determine mechanistic pathways of the osteocyte's gravity sensing ability, we evaluated in vitro gene and protein expression of osteocytes exposed to simulated microgravity. Improved understanding of the fundamental mechanisms of mechano transduction at the osteocyte cellular level may lead to revolutionary treatment otions to mitigate the effects of bone loss encountered by astronauts on long duration space missions and provide tailored treatment options for maintaining bone strength of immobilized/partially paralyzed patients here on Earth.

  14. Dynamic changes in transcriptome and cell wall composition underlying brassinosteroid-mediated lignification of switchgrass suspension cells.

    Science.gov (United States)

    Rao, Xiaolan; Shen, Hui; Pattathil, Sivakumar; Hahn, Michael G; Gelineo-Albersheim, Ivana; Mohnen, Debra; Pu, Yunqiao; Ragauskas, Arthur J; Chen, Xin; Chen, Fang; Dixon, Richard A

    2017-01-01

    Plant cell walls contribute the majority of plant biomass that can be used to produce transportation fuels. However, the complexity and variability in composition and structure of cell walls, particularly the presence of lignin, negatively impacts their deconstruction for bioenergy. Metabolic and genetic changes associated with secondary wall development in the biofuel crop switchgrass ( Panicum virgatum ) have yet to be reported. Our previous studies have established a cell suspension system for switchgrass, in which cell wall lignification can be induced by application of brassinolide (BL). We have now collected cell wall composition and microarray-based transcriptome profiles for BL-induced and non-induced suspension cultures to provide an overview of the dynamic changes in transcriptional reprogramming during BL-induced cell wall modification. From this analysis, we have identified changes in candidate genes involved in cell wall precursor synthesis, cellulose, hemicellulose, and pectin formation and ester-linkage generation. We have also identified a large number of transcription factors with expression correlated with lignin biosynthesis genes, among which are candidates for control of syringyl (S) lignin accumulation. Together, this work provides an overview of the dynamic compositional changes during brassinosteroid-induced cell wall remodeling, and identifies candidate genes for future plant genetic engineering to overcome cell wall recalcitrance.

  15. Inverse measurement of wall pressure field in flexible-wall wind tunnels using global wall deformation data

    Science.gov (United States)

    Brown, Kenneth; Brown, Julian; Patil, Mayuresh; Devenport, William

    2018-02-01

    The Kevlar-wall anechoic wind tunnel offers great value to the aeroacoustics research community, affording the capability to make simultaneous aeroacoustic and aerodynamic measurements. While the aeroacoustic potential of the Kevlar-wall test section is already being leveraged, the aerodynamic capability of these test sections is still to be fully realized. The flexibility of the Kevlar walls suggests the possibility that the internal test section flow may be characterized by precisely measuring small deflections of the flexible walls. Treating the Kevlar fabric walls as tensioned membranes with known pre-tension and material properties, an inverse stress problem arises where the pressure distribution over the wall is sought as a function of the measured wall deflection. Experimental wall deformations produced by the wind loading of an airfoil model are measured using digital image correlation and subsequently projected onto polynomial basis functions which have been formulated to mitigate the impact of measurement noise based on a finite-element study. Inserting analytic derivatives of the basis functions into the equilibrium relations for a membrane, full-field pressure distributions across the Kevlar walls are computed. These inversely calculated pressures, after being validated against an independent measurement technique, can then be integrated along the length of the test section to give the sectional lift of the airfoil. Notably, these first-time results are achieved with a non-contact technique and in an anechoic environment.

  16. Causes of secondary headache (image)

    Science.gov (United States)

    Temporomandibular joint, or TMJ, dysfunction, can be a cause of secondary headache. Secondary headaches result from underlying disorders which produce pain as a symptom. The TMJ may become painful and dysfunctional as a result ...

  17. Secondary Electron Yield on Cryogenic Surfaces as a Function of Physisorbed Gases

    CERN Document Server

    Kuzucan, Asena; Taborelli, Mauro

    2011-01-01

    In LHC the electron cloud induced by photoelectrons, gas ionization and secondary electrons emitted from the beam pipe walls could be a limitation of the performance. The electron cloud induce heat load on the cryogenic system, cause pressure rise, emittance growth and beam instabilities, which in the end will limit the beam’s lifetime. Beam- induced multipacting, which can arise through oscillatory motion of photoelectrons and low-energy secondary electrons bouncing back and forth between opposite walls of the vacuum chamber during successive passage of proton bunches, represent therefore a potential problem for the machine. The secondary electron yield (SEY) is one of the key parameters for the electron cloud build up and multipacting phenomenon. An electron cloud occurs if the metal surface secondary electron yield is high enough for electron multiplication. This parameter has been extensively studied on room temperature samples but uncertainties remain for samples at cryogenic temperature. Indeed, at l...

  18. Wall boundary layer development near the tip region of an IGV of an axial flow compressor

    Science.gov (United States)

    Lakshminarayana, B.; Sitaram, N.

    1983-01-01

    The annulus wall boundary layer inside the blade passage of the inlet guide vane (IGV) passage of a low-speed axial compressor stage was measured with a miniature five-hole probe. The three-dimensional velocity and pressure fields were measured at various axial and tangential locations. Limiting streamline angles and static pressures were also measured on the casing of the IGV passage. Strong secondary vorticity was developed. The data were analyzed and correlated with the existing velocity profile correlations. The end wall losses were also derived from these data.

  19. An experimental investigation of the seismic behavior of semi-supported steel shear walls

    DEFF Research Database (Denmark)

    Jahanpour, Alireza; Jönsson, Jeppe; Moharrami, H.

    2010-01-01

    . These half scale models represent an intermediate storey in a multi-storey steel frame. Hysteresis loops traced from the load deflection curves of these tests have an “S” shape and dissipate energy well. The system has an acceptable level of ductility, which enables its use as a lateral earthquake load......A semi-supported steel shear wall (SSSW) has been developed in the recent decade, the steel wall is connected to secondary columns that do not carry vertical loads and are used to enable the plate to enter into the post buckling region and develop a tension field. Theoretical research...

  20. Measure Guideline: Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    Energy Technology Data Exchange (ETDEWEB)

    Lstiburek, Joseph [Building Science Corporation, Westford, MA (United States); Baker, Peter [Building Science Corporation, Westford, MA (United States)

    2015-04-01

    This measure guideline provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ inches and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: fundamental building science principles relating to the use of exterior insulation on wall assemblies; design principles for tailoring this use to the specific project goals and requirements; and construction detailing to increase understanding about implementing the various design elements.