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1

COMPETI?ˆO ENTRE PLANTAS DE MILHO E SORGO (COMPETITION BETWEEN MAIZE AND SORGHUM PLANTS)  

Microsoft Academic Search

ñ The maize composite ESAM-1 was cultivated in mixed planting with the single cross maize AG-9012 and with the single cross sorghum AG-1017. The objective was to study the reaction of the composite to competition with both crops (maize and sorghum) aiming to contribute with infomation about the use of sorghum as a ìconstant genotypeî in the genetically stratified mass

PAULO S; RGIO LIMA E SILVA

2

Non-random sharing of Plantae genes.  

PubMed

The power of eukaryote genomics relies strongly on taxon sampling. This point was underlined in a recent analysis of red algal genome evolution in which we tested the Plantae hypothesis that posits the monophyly of red, green (including plants) and glaucophyte algae. The inclusion of novel genome data from two mesophilic red algae enabled us to robustly demonstrate the sisterhood of red and green algae in the tree of life. Perhaps more exciting was the finding that >1,800 putative genes in the unicellular red alga Porphyridium cruentum showed evidence of gene-sharing with diverse lineages of eukaryotes and prokaryotes. Here we assessed the correlation between the putative functions of these shared genes and their susceptibility to transfer. It turns out that genes involved in complex interactive networks such as biological regulation and transcription/translation are less susceptible to endosymbiotic or horizontal gene transfer, when compared to genes with metabolic and transporter functions. PMID:21980581

Chan, Cheong Xin; Bhattacharya, Debashish

2011-05-01

3

Hyperthermophilic endoglucanase for in planta lignocellulose conversion  

PubMed Central

Background The enzymatic conversion of lignocellulosic plant biomass into fermentable sugars is a crucial step in the sustainable and environmentally friendly production of biofuels. However, a major drawback of enzymes from mesophilic sources is their suboptimal activity under established pretreatment conditions, e.g. high temperatures, extreme pH values and high salt concentrations. Enzymes from extremophiles are better adapted to these conditions and could be produced by heterologous expression in microbes, or even directly in the plant biomass. Results Here we show that a cellulase gene (sso1354) isolated from the hyperthermophilic archaeon Sulfolobus solfataricus can be expressed in plants, and that the recombinant enzyme is biologically active and exhibits the same properties as the wild type form. Since the enzyme is inactive under normal plant growth conditions, this potentially allows its expression in plants without negative effects on growth and development, and subsequent heat-inducible activation. Furthermore we demonstrate that the recombinant enzyme acts in high concentrations of ionic liquids and can therefore degrade ?-cellulose or even complex cell wall preparations under those pretreatment conditions. Conclusion The hyperthermophilic endoglucanase SSO1354 with its unique features is an excellent tool for advanced biomass conversion. Here we demonstrate its expression in planta and the possibility for post harvest activation. Moreover the enzyme is suitable for combined pretreatment and hydrolysis applications.

2012-01-01

4

In planta passive sampling devices for assessing subsurface chlorinated solvents.  

PubMed

Contaminant concentrations in trees have been used to delineate groundwater contaminant plumes (i.e., phytoscreening); however, variability in tree composition hinders accurate measurement of contaminant concentrations in planta, particularly for long-term monitoring. This study investigated in planta passive sampling devices (PSDs), termed solid phase samplers (SPSs) to be used as a surrogate tree core. Characteristics studied for five materials included material-air partitioning coefficients (Kma) for chlorinated solvents, sampler equilibration time and field suitability. The materials investigated were polydimethylsiloxane (PDMS), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyoxymethylene (POM) and plasticized polyvinyl chloride (PVC). Both PDMS and LLDPE samplers demonstrated high partitioning coefficients and diffusivities and were further tested in greenhouse experiments and field trials. While most of the materials could be used for passive sampling, the PDMS SPSs performed best as an in planta sampler. Such a sampler was able to accurately measure trichloroethylene (TCE) and tetrachloroethylene (PCE) concentrations while simultaneously incorporating simple operation and minimal impact to the surrounding property and environment. PMID:24268175

Shetty, Mikhil K; Limmer, Matt A; Waltermire, Kendra; Morrison, Glenn C; Burken, Joel G

2014-06-01

5

Chômage et relations entre générations  

Microsoft Academic Search

[fre] Chômage et relations entre générations . Si l'on mesure, comme il est proposé dans cet article, l'intensité des rapports filiaux par l'interaction verbale (le nombre de sujets de discussion), les chômeurs n'ont avec leurs parents qu'un niveau de relations légèrement inférieur à celui des jeunes qui occupent un emploi, mais bien supérieur à celui des jeunes inactifs. Les événements

Olivier Galland

1997-01-01

6

In planta Agrobacterium-mediated transformation by vacuum infiltration.  

PubMed

In planta Agrobacterium-mediated transformation using vacuum infiltration results in transgenic Arabidopsis thaliana without the use of sterile conditions or plant regeneration. Plants are grown in pots, in standard potting mix. Agrobacterium tumefaciens, carrying an appropriate plant transformation vector, is suspended in an infiltration medium that contains, at a minimum, sucrose and the surfactant Silwet L-77. Flower buds are immersed in the suspension of A. tumefaciens. The application of a vacuum drives the bacteria into the intercellular air spaces. A portion of the Agrobacterium Ti plasmid known as the T-DNA region, which has been engineered to carry a selectable marker, becomes integrated into the plant genomic DNA. Plants are allowed to set seed. Seeds are germinated in selective conditions to recover transformants. PMID:16739579

Tague, Brian W; Mantis, Joanna

2006-01-01

7

Physiology of ex planta nitrogenase activity in Rhizobium japonicum  

SciTech Connect

Thirty-nine wild-type strains of Rhizobium japonicum have been studied for their ability to synthesize nitrogenase ex planta in defined liquid media under microaerobic conditions. Twenty-one produced more than trace amounts of acetylene reduction activity, but only a few of these yielded high activity. The oxygen response curves were similar for most of the nitrogenase-positive strains. The strains derepressible for activity had several phenotypic characteristics different from non-derepressible strains. These included slower growth and lower oxygen consumption under microaerobic conditions and lower extracellular polysaccharide production. Extracellular polysaccharide production during growth on gluconate in every nitrogenase-positive strain assayed was lower under both aerobic and microaerobic conditions than the non-depressible strains. These phenotypic characteristics may be representative of a genotype of a subspecies of R. japonicum. These studies were done in part to enlarge the base number of strains available for studies on the physiology, biochemistry, and genetics of nitrogen fixation. (35 Refs.)

Agarwal, A.K.; Keister, D.L.

1983-05-01

8

La Transpiración - Movimiento del Agua a Través de las Plantas  

NSDL National Science Digital Library

La transpiración es la pérdida de agua en forma de vapor por las plantas. El agua es absorbida del suelo por las raíces y transportada en forma líquida por el xilema hacia las hojas. En las hojas, unos pequeños poros permiten que el agua (H2O) escape a la atmósfera en forma de vapor, al tiempo que se permite la entrada de bióxido de carbono (CO2) para la fotosíntesis. De toda el agua absorbida por las plantas, menos del 5% es retenida y utilizada para crecimiento y almacenamiento. En esta lección se explicará porque las plantas pierden tanta agua, la ruta que ésta sigue dentro de la planta, como pudieran las plantas controlar la pérdida excesiva de agua y como las condiciones ambientales influyen en la pérdida de agua por las plantas.

9

Nitrogen-responsive genes are differentially regulated in planta during Fusarium oxyspsorum f. sp. lycopersici infection.  

PubMed

SUMMARY Nitrogen is an essential growth component whose availability will limit microbial spread, and as such it serves as a key control point in dictating an organism's adaptation to various environments. Little is known about fungal nutrition in planta. To enhance our understanding of this process we examined the transcriptional adaptation of Fusarium oxysporum f. sp. lycopersici, the causal agent for vascular wilt in tomato, during nutritional stress and plant colonization. Using RT-PCR and microarray technology we compared fungal gene expression in planta to axenic nitrogen starvation culture. Several expressed sequence tags, representing at least four genes, were identified that are concomitantly induced during nitrogen starvation and in planta growth. Three of these genes show similarity to a general amino acid permease, a peptide transporter and an uricase, all functioning in organic nitrogen acquisition. We further show that these genes represent a distinguishable subset of the nitrogen-responsive transcripts that respond to amino acids commonly available in the plant. Our results indicate that nitrogen starvation partially mimics in planta growth conditions, and further suggest that minute levels of organic nitrogen sources dictate the final outcome of fungal gene expression in planta. The nature of the identified transcripts suggests modes of nutrient uptake and survival for Fusarium during colonization. PMID:20565671

Divon, Hege H; Rothan-Denoyes, Beatrice; Davydov, Olga; DI Pietro, Antonio; Fluhr, Robert

2005-07-01

10

Phylogenetic Relationship of the Kingdoms Animalia, Plantae, and Fungi, Inferred from 23 Different Protein Species  

Microsoft Academic Search

The phylogenetic relationship among the kingdoms Animalia, Plantae, and Fungi remains uncertain, because of lack of solid fossil evidence. In spite of the extensive molecular phylogenetic analyses since the early report, this problem is a longstanding controversy; the proposed phylogenetic relationships differ for different authors, depending on the molecules and methods that they use. To settle this problem, we have

Naruo Nikoh; Nobuyoshi Hayase; Naoyuki Iwabe; Kei-ichi Kuma; Takashi Miyata

11

Vulnerabilidades e riscos: entre Geografia e Demografia  

Microsoft Academic Search

*** Entre as diferentes tendências de estudo dos riscos, temos inúmeras ciências que se utilizam da mesma categoria de diversas formas, ligadas a seus próprios pressupostos ontológicos, mas que pouco se comunicam. Este estudo objetiva aproximar duas dessas áreas disciplinares, que têm demonstrado preocupações semelhantes e que podem enriquecer-se mutuamente: Geografia e Demografia. A primeira, uma das mais antigas a

Eduardo Marandola Jr; Daniel Joseph Hogan

12

In vitro and in planta compatibility of insecticides and the endophytic entomopathogen, Lecanicillium lecanii.  

PubMed

In an attempt to clarify the potential role of endophytic fungi in integrated pest management, the compatibility of an endophytic isolate of Lecanicillium lecanii (Zimmermann) Gams & Zare (Hyphomycetes) with nine insecticides used against Aphis gossypii Glover (Homoptera : Aphididae) was examined both in vitro over 14 days and in planta. In the laboratory, most insecticides partially or completely inhibited the germination of conidia and growth of hyphae in nutrient-rich conditions. Endosulfan completely inhibited the germination of conidia and hyphal growth. In contrast, all insecticides were compatible with L. lecanii in planta, and the fungus was readily recovered from inoculated, colonized leaves. These data support the hypothesis that endophytic L. lecanii will be unaffected by insecticides and could be integrated in the management of pests in cotton. PMID:21424605

Gurulingappa, Pampapathy; Mc Gee, Peter; Sword, Gregory A

2011-08-01

13

Assessment of fluorescein-based fluorescent dyes for tracing Neotyphodium endophytes in planta.  

PubMed

Fluorescent dyes were assessed for their ability to stain viable hyphae of the fungi Neotyphodium lolii and N. coenophialum, symbiotic endophytes of the Pooideae grasses Lolium perenne and Festuca arundinacea, respectively. The fluorescein-based fluorophores; fluorescein diacetate (FDA), 5(6)-carboxy-fluorescein diacetate (CFDA), 5-chloromethylfluorescein diacetate (CMFDA) and the chitin-binding stain, Calcofluor while M2R, were assessed for staining of endophyte hyphae in vitro from axenic fungal cultures and in planta, including epidermal leaf sheath peels, nodes, ovaries, embryos and meristems. CMFDA produced the greatest intensity of staining of fungal hyphae and gave excellent contrast in planta compared to the plant cells. Compared to the other dyes, CMFDA was also the least affected by photo bleaching and continued to fluoresce up to 2 h after initial excitation. None of the fluorescent dyes stained fungal hyphae in seed. PMID:22802389

Card, Stuart D; Tapper, Brian A; Lloyd-West, Catherine; Wright, Kathryn M

2013-01-01

14

A quantitative PCR assay for accurate in planta quantification of the necrotrophic pathogen Phytophthora cinnamomi  

Microsoft Academic Search

A reliable method for measuring disease progression is important when evaluating susceptibility in host—pathogen interactions.\\u000a We describe a sensitive quantitative polymerase chain reaction (QPCR) assay that enables quantitative measurement of in planta DNA of the necrotrophic pathogen, Phytophthora cinnamomi, that avoids problems caused by variation in DNA extraction efficiency and degradation of host DNA during host tissue necrosis.\\u000a Normalization of

Leila Eshraghi; Nader Aryamanesh; Jonathan P. Anderson; Bryan Shearer; Jen A. McComb; Giles E. St. J. Hardy; Philip A. O’Brien

15

Development of an in planta method for transformation of alfalfa ( Medicago sativa )  

Microsoft Academic Search

Conventional methods in transforming alfalfa (Medicago sativa) require multiple tissue culture manipulations that are time-consuming and expensive, while applicable only to a few highly\\u000a regenerable genotypes. Here, we describe a simple in planta method that makes it possible to transform a commercial variety without employing selectable marker genes. Basically, young\\u000a seedlings are cut at the apical node, cold-treated, and vigorously

Jingsong Ye; Caius M. Rommens

2008-01-01

16

Rapid in planta evaluation of root expressed transgenes in chimeric soybean plants  

Microsoft Academic Search

Production of stable transgenic plants is one factor that limits rapid evaluation of tissue specific transgene expression.\\u000a To hasten the assessment of transgenes in planta, we evaluated the use of chimeric soybean seedlings expressing transgenic\\u000a products in roots. Tap roots from four-day old seedlings (cultivars ‘Jack’ and KS4704) were excised and hairy roots were induced\\u000a from hypocotyls via Agrobacterium rhizogenes-mediated

Jiarui Li; Timothy C. Todd; Harold N. Trick

2010-01-01

17

Screening for in planta protein-protein interactions combining bimolecular fluorescence complementation with flow cytometry  

PubMed Central

Understanding protein and gene function requires identifying interaction partners using biochemical, molecular or genetic tools. In plants, searching for novel protein-protein interactions is limited to protein purification assays, heterologous in vivo systems such as the yeast-two-hybrid or mutant screens. Ideally one would be able to search for novel protein partners in living plant cells. We demonstrate that it is possible to screen for novel protein-protein interactions from a random library in protoplasted Arabidopsis plant cells and recover some of the interacting partners. Our screen is based on capturing the bi-molecular complementation of mYFP between an YN-bait fusion partner and a completely random prey YC-cDNA library with FACS. The candidate interactions were confirmed using in planta BiFC assays and in planta FRET-FLIM assays. From this work, we show that the well characterized protein Calcium Dependent Protein Kinase 3 (CPK3) interacts with APX3, HMGB5, ORP2A and a ricin B-related lectin domain containing protein At2g39050. This is one of the first randomin planta screens to be successfully employed.

2012-01-01

18

Time-weighted average SPME analysis for in planta determination of cVOCs.  

PubMed

The potential of phytoscreening for plume delineation at contaminated sites has promoted interest in innovative, sensitive contaminant sampling techniques. Solid-phase microextraction (SPME) methods have been developed, offering quick, undemanding, noninvasive sampling without the use of solvents. In this study, time-weighted average SPME (TWA-SPME) sampling was evaluated for in planta quantification of chlorinated solvents. TWA-SPME was found to have increased sensitivity over headspace and equilibrium SPME sampling. Using a variety of chlorinated solvents and a polydimethylsiloxane/carboxen (PDMS/CAR) SPME fiber, most compounds exhibited near linear or linear uptake over the sampling period. Smaller, less hydrophobic compounds exhibited more nonlinearity than larger, more hydrophobic molecules. Using a specifically designed in planta sampler, field sampling was conducted at a site contaminated with chlorinated solvents. Sampling with TWA-SPME produced instrument responses ranging from 5 to over 200 times higher than headspace tree core sampling. This work demonstrates that TWA-SPME can be used for in planta detection of a broad range of chlorinated solvents and methods can likely be applied to other volatile and semivolatile organic compounds. PMID:22332592

Sheehan, Emily M; Limmer, Matt A; Mayer, Philipp; Karlson, Ulrich Gosewinkel; Burken, Joel G

2012-03-20

19

INFLUÊNCIA DO ÁCIDO INDOL-3-BUTÍRICO NO CRESCIMENTO INICIAL DE PLANTAS DE CONFREI (Symphytum officinale L.)1  

Microsoft Academic Search

RESUMO - Com o objetivo de avaliar a influência do ácido indol-3-butírico (AIB) no crescimento inicial de plantas de confrei ( Symphytum officinale L.), uma espécie medicinal, um experimento foi conduzido em casa-de-vegetação. Segmentos de rizomas, obtidos de plantas com 90 dias de idade, foram submetidos a cinco concentrações (0, 0,246, 0,492, 0,738, 0,984 mM) e três tempos de exposição

FONSÊCA CASTRO; AMAURI ALVES DE ALVARENGA

20

EntreWorld: Resources for Entrepreneurs  

NSDL National Science Digital Library

Looking to make that first million? Then EntreWorld, provided by the Ewing Marion Kauffman Foundation, is an excellent place to begin. The site is highlighted by four sections: starting your business, running your business, rapid growth, and supporting entrepreneurship. The first two sections allow users to select from an interactive search box of several topics, and retrieve annotated articles from various Internet sources. The fourth contains a potpourri of information including annotated pointers to other Internet resources in six major subject areas (pointers are also available from the Business Center area of each major section). The number of article pointers, and the annotation of each, make this site worth a visit.

2007-05-14

21

Expression of the gum operon directing xanthan biosynthesis in Xanthomonas campestris and its regulation in planta.  

PubMed

The gum gene cluster of Xanthomonas campestris pv. campestris comprises 12 genes whose products are involved in the biosynthesis of the extracellular polysaccharide xanthan. These genes are expressed primarily as an operon from a promoter upstream of the first gene, gumB. Although the regulation of xanthan synthesis in vitro has been well studied, nothing is known of its regulation in planta. A reporter plasmid was constructed in which the promoter region of the gum operon was fused to gusA. In liquid cultures, the expression of the gumgusA reporter was correlated closely with the production of xanthan, although a low basal level of beta-glucuronidase activity was seen in the absence of added carbon sources when xanthan production was very low. The expression of the gumgusA fusion also was subject to positive regulation by rpfF, which is responsible for the synthesis of the diffusible signal factor (DSF). The expression of the gumgusA fusion in bacteria recovered from inoculated turnip leaves was maximal at the later phases of growth and was subject to regulation by rpfF. These results provide indirect support for the operation of the DSF regulatory system in bacteria in planta. PMID:11386372

Vojnov, A A; Slater, H; Daniels, M J; Dow, J M

2001-06-01

22

Biosynthesis, structural, and functional attributes of tocopherols in planta; past, present, and future perspectives.  

PubMed

Tocopherols are lipophilic molecules, ubiquitously synthesized in all photosynthetic organisms. Being a group of vitamin E compounds, they play an essential role in human nutrition and health. Despite their structural and functional attributes as important antioxidants in plants, it would be misleading to ignore the potential roles of tocopherols beyond their antioxidant properties in planta. Detailed characterization of mutants and transgenic plants, including Arabidopsis (vte1, vte2, vte4, and so on), maize (sxd1) mutants, and transgenic potato and tobacco lines altered in tocopherol biosynthesis and contents, has led to surprising outcomes regarding the additional functions of these molecules. Thus, the aim of this review is to highlight the past and present research findings on tocopherols' structural, biosynthesis, and functional properties in plants. Special emphasis is given to their suggested functions in planta, such as cell signaling, hormonal interactions, and coordinated response of tocopherols to other antioxidants under abiotic stresses. Moreover, some important questions about possible new functions of tocopherols will be discussed as future prospects to stimulate further research. PMID:23713813

Hussain, Nazim; Irshad, Faiza; Jabeen, Zahra; Shamsi, Imran Haider; Li, Zhilan; Jiang, Lixi

2013-07-01

23

In planta function of compatible solute transporters of the AtProT family  

PubMed Central

The three proline transporters of Arabidopsis thaliana (AtProTs) transport the compatible solutes proline and glycine betaine and the stress-induced compound ?-aminobutyric acid when expressed in heterologous systems. The aim of the present study was to show transport and physiological relevance of these three AtProTs in planta. Using single, double, and triple knockout mutants and AtProT-overexpressing lines, proline content, growth on proline, transport of radiolabelled betaine, and expression of AtProT genes and enzymes of proline metabolism were analysed. AtProT2 was shown to facilitate uptake of L- and D-proline as well as [14C]glycine betaine in planta, indicating a role in the import of compatible solutes into the root. Toxic concentrations of L- and D-proline resulted in a drastic growth retardation of AtProT-overexpressing plants, demonstrating the need for a precise regulation of proline uptake and/or distribution. Furthermore evidence is provided that AtProT genes are highly expressed in tissues with elevated proline content—that is, pollen and leaf epidermis.

Lehmann, Silke; Gumy, Christophe; Blatter, Eva; Boeffel, Silke; Fricke, Wieland; Rentsch, Doris

2011-01-01

24

Simultaneous specific in planta visualization of root-colonizing fungi using fluorescence in situ hybridization (FISH).  

PubMed

In planta detection of mutualistic, endophytic, and pathogenic fungi commonly colonizing roots and other plant organs is not a routine task. We aimed to use fluorescence in situ hybridization (FISH) for simultaneous specific detection of different fungi colonizing the same tissue. We have adapted ribosomal RNA (rRNA) FISH for visualization of common mycorrhizal (arbuscular- and ectomycorrhiza) and endophytic fungi within roots of different plant species. Beside general probes, we designed and used specific ones hybridizing to the large subunit of rRNA with fluorescent dyes chosen to avoid or reduce the interference with the autofluorescence of plant tissues. We report here an optimized efficient protocol of rRNA FISH and the use of both epifluorescence and confocal laser scanning microscopy for simultaneous specific differential detection of those fungi colonizing the same root. The method could be applied for the characterization of other plant-fungal interactions, too. In planta FISH with specific probes labeled with appropriate fluorescent dyes could be used not only in basic research but to detect plant colonizing pathogenic fungi in their latent life-period. PMID:24221902

Vági, Pál; Knapp, Dániel G; Kósa, Annamária; Seress, Diána; Horváth, Aron N; Kovács, Gábor M

2014-05-01

25

In planta transformation method for T-DNA transfer in orchids  

NASA Astrophysics Data System (ADS)

Transgenic plant technology is an efficient tool to study the function of gene(s) in plant. The most popular and widely used technique is Agrobacterium-mediated transformation in which cocultivation was done by immersing the plant tissues/organ in overnight bacterial cultured for about 30 minutes to one hour under in vitro condition. In this experiment, we developed more easier technique that omitted the in vitro step during cocultivation with Agrobacterium, namely in planta transformation method. Pollinaria (compact pollen mass of orchid) of Phalaenopsis amabilis and Spathoglottis plicata orchids were used as target explants that were immersed into bacterial culture for 30 minutes, then dried up the pollinaria, the transformed pollinaria was used to pollinate orchid flowers. The T-DNA used for this experiments were Ubipro?PaFT/A. tumefaciens GV3101 for P. amabilis and MeEF1?2 pro?GUS/ A. tumefaciens LBA 4404 for S.plicata. Seeds that were produced from pollinated flowers were grown onto 10 mg/l hygromicin containing NP (New Phalaenopsis) medium. The existance of transgene in putative transformant protocorm (developing orchid embryo) genome was confirmed using PCR with specific primers of either PaFT or GUS genes. Histochemical GUS assay was also performed to the putative transformants. The result showed that transformation frequencies were 2.1 % in P. amabilis, and 0,53% in S. plicata. These results indicates that in planta transformation method could be used for Agrobacterium-mediated genetic transformation, with advantage easier and more secure work from contaminants than that of the in vitro method.

Semiarti, Endang; Purwantoro, Aziz; Mercuriani, Ixora S.; Anggriasari, Anida M.; Jang, Seonghoe; Suhandono, Sony; Machida, Yasunori; Machida, Chiyoko

2014-03-01

26

The Ustilago maydis b mating type locus controls hyphal proliferation and expression of secreted virulence factors in planta.  

PubMed

Sexual development in fungi is controlled by mating type loci that prevent self-fertilization. In the phytopathogenic fungus Ustilago maydis, the b mating type locus encodes two homeodomain proteins, termed bE and bW. After cell fusion, a heterodimeric bE/bW complex is formed if the proteins are derived from different alleles. The bE/bW complex is required and sufficient to initiate pathogenic development and sexual reproduction; for the stages of pathogenic development succeeding plant penetration, however, its role was unclear. To analyse b function during in planta development, we generated a temperature-sensitive bE(ts) protein by exchange of a single amino acid. bE(ts) strains are stalled in pathogenic development at restrictive temperature in planta, and hyphae develop enlarged, bulbous cells at their tips that contain multiple nuclei, indicating a severe defect in the control and synchronization of cell cycle and cytokinesis. DNA array analysis of bE(ts) mutant strains in planta revealed a b-dependent regulation of genes encoding secreted proteins that were shown to influence fungal virulence. Our data demonstrate that in U. maydis the b heterodimer is not only essential to establish the heterodikaryon after mating of two compatible sporidia and to initiate fungal pathogenicity, but also to sustain in planta proliferation and ensure sexual reproduction. PMID:19943901

Wahl, Ramon; Zahiri, Alexander; Kämper, Jörg

2010-01-01

27

Qualidade de frutos de cinco híbridos de melão rendilhado em função do número de frutos por planta  

Microsoft Academic Search

RESUMO-Este trabalho teve por objetivo avaliar a qualidade de cinco híbridos de melão rendilhado, com dois e três frutos por planta, utilizando fibra da casca de coco e fertirrigação. Para tanto, foi instalado um experimento em casa de vegetação na UNESP-FCAV, Câmpus de Jaboticabal, com delineamento experimental em blocos ao acaso, em esquema fatorial 5 x 2, com quatro repetições.

Renata Castoldi; Hamilton César de Oliveira Charlo; Pablo Forlan Vargas; Leila Trevizan Braz

2008-01-01

28

Efficacy of phosphonic acid, metalaxyl-M and copper hydroxide against Phytophthora ramorum in vitro and in planta  

Microsoft Academic Search

The ability of metalaxyl-M, phosphonic acid in the form of phosphonate, and copper hydroxide to inhibit different stages in the life cycle of Phytophthora ramorum , the causal agent of sudden oak death (SOD), was tested in vitro using 12 isolates from the North American forest lineage. In addition, experiments were conducted in planta to study the ability of phosphonic

M. Garbelotto; T. Y. Harnik; D. J. Schmidt

2008-01-01

29

Biologia floral, microsporogênese e número cromossômico em cinco espécies de plantas utilizadas na medicina popular no Rio Grande do Sul  

Microsoft Academic Search

RESUMO: Onze populações de cinco espécies de plantas medicinais utilizadas no Rio Grande do Sul, foram observadas quanto ao período de floração, durante três anos e estudadas citogeneticamente. Discaria americana e Matricharia chamomilla, florescem preferencialmente no inverno, Foeniculun vulgare e Symphytum officinale, nas estações mais quentes e Plectranthus barbatus floresce em estações mais amenas. Na meiose da microsporogênese, formaram-se 11

G. M. PEREIRA; DA SILVA

2006-01-01

30

Parler en famille : les échanges entre parents et enfants  

Microsoft Academic Search

[fre] Parler en famille : les échanges entre parents et enfants . L'étendue des sujets abordés par les discussions entre parents et enfants parvenus à l'âge adulte est un indicateur de l'intensité de leurs rapports. Il montre que davantage que l'âge, l'installation en couple tend à amenuiser ces liens : une rupture plus nette se manifeste chez les jeunes femmes,

Olivier Galland

1997-01-01

31

In planta selfing and oospore production of Phytophthora cinnamomi in the presence of Acacia pulchella.  

PubMed

This paper provides the first evidence of A2 type 1 and type 2 isolates of Phytophthora cinnamomi producing selfed oospores in planta in an Australian soil and in a potting mix. Oospores were observed in infected lupin (Lupinus angustifolius) roots incubated for 7d either in the substrate under potted Acacia pulchella plants, or in soils collected from under and near varieties of A. pulchella in jarrah (Eucalyptus marginata) forest. The A2 type isolates varied in their ability to produce selfed oospores and none were produced by A1 isolates. The gametangial association was amphigynous and spores were predominantly spherical with diameters from 13-40 microm. The oospores were viable but dormant. Two A2 type isolates produced small numbers of selfed oospores with amphigynous antheridia axenically in Ribeiro's liquid medium within 30 d, and one A2 type 2 isolate produced oospores after mating with an A1 strain. Evidence is presented that the presence of roots of Acacia pulchella, and particularly A. pulchella var. glaberrima and var. goadbyi, enhances the production of oospores. PMID:17350243

Jayasekera, Arunodini U; McComb, Jen A; Shearer, Bryan L; Hardy, Giles E St J

2007-03-01

32

Characterization of VIP1 activity as a transcriptional regulator in vitro and in planta  

PubMed Central

VIP1 (VirE2 interacting protein 1), initially discovered as a host protein involved in Agrobacterium-plant cell DNA transfer, is a transcription factor of the basic leucine-zipper (bZIP) domain family that regulates several defence-related genes in Arabidopsis. We have developed assays to assess VIP1 binding to its DNA target in vitro and transcriptional activation efficiency in planta. Several point mutations in the VIP1 response element VRE affected the VIP1 activity, and a strong correlation between VIP1-VRE binding and transcriptional activation levels was observed. Promoter activation by VIP1 was influenced by bacterial and plant proteins known to interact with VIP1 during Agrobacterium infection, i.e., VirE2, VirF and VIP2. VirF, an F-box protein, strongly decreased VIP1 transcriptional activation ability, but not its binding to VRE in vitro, most likely by triggering proteasomal degradation of VIP1. Finally, activation of a VRE-containing promoter was observed in dividing cells, probably resulting from activation of endogenous VIP1.

Lacroix, Benoit; Citovsky, Vitaly

2013-01-01

33

Native-sized spider silk proteins synthesized in planta via intein-based multimerization.  

PubMed

The synthesis of native-sized proteins is a pre-requisite for exploiting the potential of spider silk as a bio-based material. The unique properties of spider silk, such as extraordinary tensile strength and elasticity, result from the highly repetitive nature of spider silk protein motifs. The present report describes the combination of spider silk flagelliform protein (FLAG) production in the endoplasmic reticulum of tobacco plant leaf cells with an intein-based posttranslational protein fusion technology. The repeated ligation of FLAG monomers resulted in the formation of large multimers. This method avoids the need for highly repetitive transgenes, which may result in a higher genetic and transcriptional stability. Here we show, for the first time, the production of synthetic, high molecular weight spider silk proteins larger than 250 kDa based on the assembly of protein monomers via intein-mediated trans-splicing in planta. The resulting multimeric structures form microfibers, thereby demonstrating their great potential as a biomaterial. PMID:23001519

Hauptmann, Valeska; Weichert, Nicola; Menzel, Matthias; Knoch, Dominic; Paege, Norman; Scheller, Jürgen; Spohn, Uwe; Conrad, Udo; Gils, Mario

2013-04-01

34

Endophytic Colonization and In Planta Nitrogen Fixation by a Herbaspirillum sp. Isolated from Wild Rice Species  

PubMed Central

Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum, Ideonella, Enterobacter, and Azospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and 15N2 gas incorporation assays. Therefore, we conclude that Herbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis.

Elbeltagy, Adel; Nishioka, Kiyo; Sato, Tadashi; Suzuki, Hisa; Ye, Bin; Hamada, Toru; Isawa, Tsuyoshi; Mitsui, Hisayuki; Minamisawa, Kiwamu

2001-01-01

35

Root internalization, transport and in-planta survival of Salmonella enterica serovar Newport in sweet basil.  

PubMed

It is now acknowledged that food-borne pathogens present in the irrigation water or soil can become associated with crop plants in the field, penetrate internal plant tissues via the root, translocate and survive inside plants. Only little information is available concerning interaction between enteric pathogens and plants. The present study evaluated the potential for contamination of the aromatic plant, sweet basil during cultivation, by Salmonella enterica serovar Newport. Root internalization was plant-age-dependent, with the highest susceptibility occurring at the beginning of the rapid growth phase of the root. Higher incidence of internalization was detected in vegetative than reproductive plant organs, pointing at bacterial transport in the transpiration stream. Internalized Salmonella survived only planta survival was limited to less than 30?h. These findings imply that leaf surface contamination, rather than root internalization, may pose higher risk for human infection following consumption of contaminated basil. PMID:23757144

Gorbatsevich, Elena; Sela Saldinger, Shlomo; Pinto, Riky; Bernstein, Nirit

2013-02-01

36

Detection and visualization of an exopolysaccharide produced by Xylella fastidiosa in vitro and in planta.  

PubMed

Many phytopathogenic bacteria, such as Ralstonia solanacearum, Pantoea stewartii, and Xanthomonas campestris, produce exopolysaccharides (EPSs) that aid in virulence, colonization, and survival. EPS can also contribute to host xylem vessel blockage. The genome of Xylella fastidiosa, the causal agent of Pierce's disease (PD) of grapevine, contains an operon that is strikingly similar to the X. campestris gum operon, which is responsible for the production of xanthan gum. Based on this information, it has been hypothesized that X. fastidiosa is capable of producing an EPS similar in structure and composition to xanthan gum but lacking the terminal mannose residue. In this study, we raised polyclonal antibodies against a modified xanthan gum polymer similar to the predicted X. fastidiosa EPS polymer. We used enzyme-linked immunosorbent assay to quantify production of EPS from X. fastidiosa cells grown in vitro and immunolocalization microscopy to examine the distribution of X. fastidiosa EPS in biofilms formed in vitro and in planta and assessed the contribution of X. fastidiosa EPS to the vascular occlusions seen in PD-infected grapevines. PMID:17827325

Roper, M Caroline; Greve, L Carl; Labavitch, John M; Kirkpatrick, Bruce C

2007-11-01

37

A functional screen to characterize the secretomes of eukaryotic pathogens and their hosts in planta.  

PubMed

Complex suites of proteins that are secreted by plants and phytopathogens into the plant apoplast play crucial roles in surveillance, assault, defense, and counter-defense. High-throughput genome-scale strategies are being developed to better understand the nature of these "secretomes" and the identity of pathogen-derived effector proteins that subvert plant defenses and promote pathogenicity. Although combined bioinformatic and experimental approaches recently have provided comprehensive coverage of secreted proteins from bacterial phytopathogens, far less is known about the secretomes and batteries of effectors of eukaryotic phytopathogens; notably fungi and oomycetes. The yeast secretion trap (YST) represents a potentially valuable technique to simultaneously target pathogen and host secretomes in infected plant material. A YST screen, using a new vector system, was applied to study the interaction between tomato (Solanum lycopersicum) and the oomycete Phytophthora infestans, revealing sets of genes encoding secreted proteins from both pathogen and host. Most of those from the oomycete had no identifiable function and were detectable in planta only during pathogenesis, underlining the value of YST as a tool to identify new candidate effectors and pathogenicity factors. In addition, the majority of the P. infestans proteins had homologs in the genomes of the related oomycetes R. sojae and P. ramorum. PMID:17153921

Lee, Sang-Jik; Kelley, Brendan S; Damasceno, Cynthia M B; St John, Bonnie; Kim, Byung-Soo; Kim, Byung-Dong; Rose, Jocelyn K C

2006-12-01

38

Detection and Visualization of an Exopolysaccharide Produced by Xylella fastidiosa In Vitro and In Planta?  

PubMed Central

Many phytopathogenic bacteria, such as Ralstonia solanacearum, Pantoea stewartii, and Xanthomonas campestris, produce exopolysaccharides (EPSs) that aid in virulence, colonization, and survival. EPS can also contribute to host xylem vessel blockage. The genome of Xylella fastidiosa, the causal agent of Pierce's disease (PD) of grapevine, contains an operon that is strikingly similar to the X. campestris gum operon, which is responsible for the production of xanthan gum. Based on this information, it has been hypothesized that X. fastidiosa is capable of producing an EPS similar in structure and composition to xanthan gum but lacking the terminal mannose residue. In this study, we raised polyclonal antibodies against a modified xanthan gum polymer similar to the predicted X. fastidiosa EPS polymer. We used enzyme-linked immunosorbent assay to quantify production of EPS from X. fastidiosa cells grown in vitro and immunolocalization microscopy to examine the distribution of X. fastidiosa EPS in biofilms formed in vitro and in planta and assessed the contribution of X. fastidiosa EPS to the vascular occlusions seen in PD-infected grapevines.

Roper, M. Caroline; Greve, L. Carl; Labavitch, John M.; Kirkpatrick, Bruce C.

2007-01-01

39

Rapid in planta evaluation of root expressed transgenes in chimeric soybean plants.  

PubMed

Production of stable transgenic plants is one factor that limits rapid evaluation of tissue specific transgene expression. To hasten the assessment of transgenes in planta, we evaluated the use of chimeric soybean seedlings expressing transgenic products in roots. Tap roots from four-day old seedlings (cultivars 'Jack' and KS4704) were excised and hairy roots were induced from hypocotyls via Agrobacterium rhizogenes-mediated transformation. Inoculated hypocotyls were screened on a MS-based medium containing either 200 mg/L kanamycin or 20 mg/L hygromycin. Beta-glucuronidase (GUS) activity assay indicated that highest GUS expression was observed in hypocotyls exposed to a 4-d pre-inoculation time, a neutral pH (7.0) for the co-cultivation medium. A 170-bp of the Fib-1 gene and 292-bp of the Y25C1A.5 gene fragments, both related to nematode reproduction and fitness, were cloned independently into pANDA35HK vector using a Gateway cloning strategy. The resulting RNAi constructs of the genes fragments were transformed into soybean using the chimeric hairy root system and evaluated for its effect on soybean cyst nematode (Heterodera glycines) fecundity. Confirmation of transformation was attained by polymerase chain reaction and Southern-blot analysis, and some potential for suppression of H. glycines reproduction was detected for the two constructs. This method takes on average four weeks to produce chimeric plants ready for transgene analysis. PMID:20012965

Li, Jiarui; Todd, Timothy C; Trick, Harold N

2010-02-01

40

Mexican papita viroid and tomato planta macho viroid belong to a single species in the genus Pospiviroid.  

PubMed

Tomato planta macho viroid (TPMVd) and Mexican papita viroid (MPVd) are two closely related (>90% sequence identity) members of the genus Pospiviroid. Their current status as members of separate species is based upon the reported ability of TPMVd to replicate in Gomphrena globosa and the inability of this viroid to evoke flower break in N. glutinosa. Characterization of a viroid recently isolated from diseased tomato plants grown in Mexico (identical to GenBank accession GQ131573) casts doubt on this earlier report and indicates that these viroids should be classified as members of a single species. Giving priority to the older name, we propose including both of these viroids in the current species Tomato planta macho viroid. PMID:21442229

Verhoeven, J Th J; Roenhorst, J W; Owens, R A

2011-08-01

41

Phylogeny of nuclear-encoded plastid-targeted proteins supports an early divergence of glaucophytes within Plantae.  

PubMed

The phylogenetic position of the glaucophyte algae within the eukaryotic supergroup Plantae remains to be unambiguously established. Here, we assembled a multigene data set of conserved nuclear-encoded plastid-targeted proteins of cyanobacterial origin (i.e., through primary endosymbiotic gene transfer) from glaucophyte, red, and green (including land plants) algae to infer the branching order within this supergroup. We find strong support for the early divergence of glaucophytes within the Plantae, corroborating 2 important putatively ancestral characters shared by glaucophyte plastids and the cyanobacterial endosymbiont that gave rise to this organelle: the presence of a peptidoglycan deposition between the 2 organelle membranes and carboxysomes. Both these traits were apparently lost in the common ancestor of red and green algae after the divergence of glaucophytes. PMID:17827169

Reyes-Prieto, Adrian; Bhattacharya, Debashish

2007-11-01

42

EFEITOS DE HERBICIDAS NO CONTROLE DE PLANTAS DANINHAS NA CULTURA DO FEIJÃO-MUNGO-VERDE (Vigna radiata (L.) WILCZEK)  

Microsoft Academic Search

RESUMO - Foram conduzidos dois experimentos de campo com o feijão -mungo-verde (Vigna radiata (L.) Wilczek), variedade Ouro Verde: um no verão-outono e outro na primavera-verão, em Coimbra -MG, com o objetivo de verificar o efeito de diferentes herbicidas sobre o control e de plantas daninhas e sobre a cultura. Foi usado o delineamento experimental em blocos ao acaso, com

JOSÉ ROBERTO ANTONIOL FONTES; GERALDO ANTÔNIO DE ANDRADE ARAÚJO; ANTÔNIO ALBERTO DA SILVA; ANTÔNIO AMÉRICO CARDOSO

43

An efficient in planta transformation of Jatropha curcas (L.) and multiplication of transformed plants through in vivo grafting.  

PubMed

An efficient and reproducible Agrobacterium-mediated in planta transformation was developed in Jatropha curcas. The various factors affecting J. curcas in planta transformation were optimized, including decapitation, Agrobacterium strain, pin-pricking, vacuum infiltration duration and vacuum pressure. Simple vegetative in vivo cleft grafting method was adopted in the multiplication of transformants without the aid of tissue culture. Among the various parameters evaluated, decapitated plants on pin-pricking and vacuum infiltrated at 250 mmHg for 3 min with the Agrobacterium strain EHA 105 harbouring the binary vector pGA 492 was proved to be efficient in all terms with a transformation efficiency of 62.66%. Transgene integration was evinced by the GUS histochemical analysis, and the GUS positive plants were subjected to grafting. Putatively transformed J. curcas served as "Scion" and the wild type J. curcas plant severed as "Stock". There was no occurrence of graft rejection and the plants were then confirmed by GUS histochemical analysis, polymerase chain reaction (PCR) and Southern hybridization. Genetic stability of the grafted plants was evaluated by using randomly amplified polymorphic DNA (RAPD), marker which showed 100% genetic stability between mother and grafted plants. Thus, an efficient in planta transformation and grafting based multiplication of J. curcas was established. PMID:24150424

Jaganath, Balusamy; Subramanyam, Kondeti; Mayavan, Subramanian; Karthik, Sivabalan; Elayaraja, Dhandapani; Udayakumar, Rajangam; Manickavasagam, Markandan; Ganapathi, Andy

2014-05-01

44

Nodularin, a cyanobacterial toxin, is synthesized in planta by symbiotic Nostoc sp.  

PubMed Central

The nitrogen-fixing bacterium, Nostoc, is a commonly occurring cyanobacterium often found in symbiotic associations. We investigated the potential of cycad cyanobacterial endosymbionts to synthesize microcystin/nodularin. Endosymbiont DNA was screened for the aminotransferase domain of the toxin biosynthesis gene clusters. Five endosymbionts carrying the gene were screened for bioactivity. Extracts of two isolates inhibited protein phosphatase 2A and were further analyzed using electrospray ionization mass spectrometry (ESI-MS)/MS. Nostoc sp. ‘Macrozamia riedlei 65.1' and Nostoc sp. ‘Macrozamia serpentina 73.1' both contained nodularin. High performance liquid chromatography (HPLC) HESI-MS/MS analysis confirmed the presence of nodularin at 9.55±2.4?ng??g?1 chlorophyll a in Nostoc sp. ‘Macrozamia riedlei 65.1' and 12.5±8.4?ng??g?1 Chl a in Nostoc sp. ‘Macrozamia serpentina 73.1' extracts. Further scans indicated the presence of the rare isoform [L-Har2] nodularin, which contains ?-homoarginine instead of ?-arginine. Nodularin was also present at 1.34±0.74?ng?ml?1 (approximately 3?pmol per g plant ww) in the methanol root extracts of M. riedlei MZ65, while the presence of [L-Har2] nodularin in the roots of M. serpentina MZ73 was suggested by HPLC HESI-MS/MS analysis. The ndaA-B and ndaF genomic regions were sequenced to confirm the presence of the hybrid polyketide/non-ribosomal gene cluster. A seven amino-acid insertion into the NdaA-C1 domain of N. spumigena NSOR10 protein was observed in all endosymbiont-derived sequences, suggesting the transfer of the nda cluster from N. spumigena to terrestrial Nostoc species. This study demonstrates the synthesis of nodularin and [L-Har2] nodularin in a non-Nodularia species and the production of cyanobacterial hepatotoxin by a symbiont in planta.

Gehringer, Michelle M; Adler, Lewis; Roberts, Alexandra A; Moffitt, Michelle C; Mihali, Troco K; Mills, Toby J T; Fieker, Claus; Neilan, Brett A

2012-01-01

45

Bioinspired engineering study of Plantae vascules for self-healing composite structures  

PubMed Central

This paper presents the first conceptual study into creating a Plantae-inspired vascular network within a fibre-reinforced polymer composite laminate, which provides an ongoing self-healing functionality without incurring a mass penalty. Through the application of a ‘lost-wax’ technique, orthogonal hollow vascules, inspired by the ‘ray cell’ structures found in ring porous hardwoods, were successfully introduced within a carbon fibre-reinforced epoxy polymer composite laminate. The influence on fibre architecture and mechanical behaviour of single vascules (located on the laminate centreline) when aligned parallel and transverse to the local host ply was characterized experimentally using a compression-after-impact test methodology. Ultrasonic C-scanning and high-resolution micro-CT X-ray was undertaken to identify the influence of and interaction between the internal vasculature and impact damage. The results clearly show that damage morphology is influenced by vascule orientation and that a 10 J low-velocity impact damage event is sufficient to breach the vasculature; a prerequisite for any subsequent self-healing function. The residual compressive strength after a 10 J impact was found to be dependent upon vascule orientation. In general, residual compressive strength decreased to 70 per cent of undamaged strength when vasculature was aligned parallel to the local host ply and a value of 63 per cent when aligned transverse. This bioinspired engineering study has illustrated the potential that a vasculature concept has to offer in terms of providing a self-healing function with minimum mass penalty, without initiating premature failure within a composite structure.

Trask, R. S.; Bond, I. P.

2010-01-01

46

Nodularin, a cyanobacterial toxin, is synthesized in planta by symbiotic Nostoc sp.  

PubMed

The nitrogen-fixing bacterium, Nostoc, is a commonly occurring cyanobacterium often found in symbiotic associations. We investigated the potential of cycad cyanobacterial endosymbionts to synthesize microcystin/nodularin. Endosymbiont DNA was screened for the aminotransferase domain of the toxin biosynthesis gene clusters. Five endosymbionts carrying the gene were screened for bioactivity. Extracts of two isolates inhibited protein phosphatase 2A and were further analyzed using electrospray ionization mass spectrometry (ESI-MS)/MS. Nostoc sp. 'Macrozamia riedlei 65.1' and Nostoc sp. 'Macrozamia serpentina 73.1' both contained nodularin. High performance liquid chromatography (HPLC) HESI-MS/MS analysis confirmed the presence of nodularin at 9.55±2.4?ng ?g-1 chlorophyll a in Nostoc sp. 'Macrozamia riedlei 65.1' and 12.5±8.4?ng??g-1 Chl a in Nostoc sp. 'Macrozamia serpentina 73.1' extracts. Further scans indicated the presence of the rare isoform [L-Har(2)] nodularin, which contains L-homoarginine instead of L-arginine. Nodularin was also present at 1.34±0.74?ng?ml(-1) (approximately 3?pmol per g plant ww) in the methanol root extracts of M. riedlei MZ65, while the presence of [L-Har(2)] nodularin in the roots of M. serpentina MZ73 was suggested by HPLC HESI-MS/MS analysis. The ndaA-B and ndaF genomic regions were sequenced to confirm the presence of the hybrid polyketide/non-ribosomal gene cluster. A seven amino-acid insertion into the NdaA-C1 domain of N. spumigena NSOR10 protein was observed in all endosymbiont-derived sequences, suggesting the transfer of the nda cluster from N. spumigena to terrestrial Nostoc species. This study demonstrates the synthesis of nodularin and [L-Har(2)] nodularin in a non-Nodularia species and the production of cyanobacterial hepatotoxin by a symbiont in planta. PMID:22456448

Gehringer, Michelle M; Adler, Lewis; Roberts, Alexandra A; Moffitt, Michelle C; Mihali, Troco K; Mills, Toby J T; Fieker, Claus; Neilan, Brett A

2012-10-01

47

Floral benzenoid carboxyl methyltransferases: From in vitro to in planta function  

PubMed Central

Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT’s three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in planta depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses might represent the ancestor for the presently existing floral genes which during evolution gained different expression profiles and encoded enzymes with the ability to accept structurally similar substrates.

Effmert, Uta; Saschenbrecker, Sandra; Ross, Jeannine; Negre, Florence; Fraser, Chris M.; Noel, Joseph P.; Dudareva, Natalia; Piechulla, Birgit

2010-01-01

48

Un intento de comparación entre Estados Unidos y Europa  

Microsoft Academic Search

La comparación entre Estados Unidos y Europa puede hacerse de muy diversas maneras, pero, en cualquier caso, conviene definir lo que hay que entender por Europa. Al margen de conside raciones de orden histórico, conceptual e incluso antropológico, que nos llevarían al muy interesante debate ideológico actual, parece que, dentro de los límites a que esta contribución al Libro Marrón

Rafael Termes

49

La contradicción entre identidad vivida e identificación jurídico-política  

Microsoft Academic Search

Este artículo quiere llamar la atención de los antropólogos españoles sobre una contradicción implícita, por no decir sepultada, en los discursos sobre la identidad. Se trata de la contradicción entre la identidad como expresión de lo vivido y la identidad como quimera, y a la vez, estigma clasificatorio. Si bien, varias opiniones tratan de hacer pasar lo segundo por lo

Ignasi Terradas i Saborit

2004-01-01

50

In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1  

PubMed Central

Background Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo), induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc). Results Changes in gene expression of the African Xoo strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH Xoo DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai) with bacteria grown in vitro. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The Xoo MAI1 non-redundant set of sequences was compared against several X. oryzae genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis. Conclusions This is the first report to compare the expression of Xoo genes in planta across different time points during infection. This work shows that as-yet-unidentified and potentially new virulence factors are appearing in an emerging African pathogen. It also confirms that African Xoo strains do differ from their Asian counterparts, even at the transcriptional level.

2010-01-01

51

The plant pathogen Erwinia amylovora produces acyl-homoserine lactone signal molecules in vitro and in planta.  

PubMed

We report for the first time the production of acyl homoserine lactones (AHLs) by Erwina amylovora, an important quarantine bacterial pathogen that causes fire blight in plants. E. amylovora produces one N-acyl homoserine lactone [a N-(3-oxo-hexanoyl)-homoserine lactone or a N-(3-hydroxy-hexanoyl)-homoserine lactone] quorum sensing signal molecule both in vitro and in planta (pear plant). Given the involvement of AHLs in plant pathogenesis, we speculate that AHL-dependent quorum sensing could play an important role in the regulation of E. amylovora virulence. PMID:15598530

Venturi, Vittorio; Venuti, Chiara; Devescovi, Giulia; Lucchese, Carla; Friscina, Arianna; Degrassi, Giuliano; Aguilar, Claudio; Mazzucchi, Umberto

2004-12-15

52

In planta expression of a mature Der p 1 allergen isolated from an Italian strain of Dermatophagoides pteronyssinus.  

PubMed

European (Dermatophagoides pteronyssinus) and American (Dermatophagoides farinae) house dust mite species are considered the most common causes of asthma and allergic symptoms worldwide. Der p 1 protein, one of the main allergens of D. pteronyssinus, is found in high concentration in mites faecal pellets, which can became easily airborne and, when inhaled, can cause perennial rhinitis and bronchial asthma. Here we report the isolation of the Der p 1 gene from an Italian strain of D. pteronyssinus and the PVX-mediated expression of its mature form (I-rDer p 1) in Nicotiana benthamiana plants. Human sera from characterized allergic patients were used for IgE binding inhibition assays to test the immunological reactivity of I-rDer p 1 produced in N. benthamiana plants. The binding properties of in planta produced I-rDer p 1 versus the IgE of patients sera were comparable to those obtained on Der p 1 preparation immobilized on a microarray. In this paper we provide a proof of concept for the production of an immunologically active form of Der p 1 using a plant viral vector. These results pave the way for the development of diagnostic allergy tests based on in planta produced allergens. PMID:21904913

Marconi, Gianpiero; Albertini, Emidio; Mari, Adriano; Palazzo, Paola; Porceddu, Andrea; Raggi, Lorenzo; Bolis, Luigi; Lancioni, Hovirag; Palomba, Antonella; Lucentini, Livia; Lanfaloni, Luisa; Marcucci, Francesco; Falcinelli, Mario; Panara, Fausto

2012-06-01

53

Quorum-sensing signals produced by plant-growth promoting Burkholderia strains under in vitro and in planta conditions.  

PubMed

The genus Burkholderia is a heterogeneous group with extraordinary nutritional versatility and which occupies a diversity of niches. In recent decades, members of Burkholderia have been shown to be active participants in plant-microbe interactions, imparting beneficial effects as plant-growth-promoting bacteria (PGPB) or as pathogens. The study of quorum sensing and cell-density-dependent gene regulation, which play an important role in host colonization and pathogenesis, is extremely important in such a versatile organism. We report the identification and characterization by thin-layer chromatography (TLC) of N-acyl homoserine lactone (HSL) quorum sensing signal molecules by PGP Burkholderia. The Burkholderia spp. strains CBMB40, CBPB-HOD and CBPB-HIM investigated in this study were isolated from rice and possessed one or more PGP characteristics. Culture extracts of these strains contained detectable levels of hexanoyl (C(6)-), heptanoyl (C(7)-) and octanoyl (C(8)-) HSLs. Burkholderia sp. strain CBMB40 produced an additional molecule that migrated along decanoyl (C(10)-) HSL. Inoculation of HSL-producing Burkholderia strains through seed bacterization to canola stimulated root elongation. Signal molecules produced by Burkholderia strains could also be detected in planta, as determined by plate assays and TLC analysis of plant extracts. This study advances the hypothesis that signaling molecules by PGPB in planta might play a substantial role in increasing the pathogen resistance of plants. PMID:17350232

Poonguzhali, Selvaraj; Madhaiyan, Munusamy; Sa, Tongmin

2007-04-01

54

Characterization of in planta-induced rust genes isolated from a haustorium-specific cDNA library.  

PubMed

Rust fungi are plant parasites that depend on living host tissue for growth. For invasion of leaves, dikaryotic urediospores differentiate germ tubes and infection structures that penetrate through stomata. Biotrophic growth occurs by intercellular mycelia that form haustoria within host cells. A cDNA library was constructed from haustoria isolated from broad bean leaves infected by Uromyces fabae. Differential screening revealed that a high proportion (19%) of the haustorial cDNAs are specifically expressed in planta but are not expressed, or are much weaker, in germlings or infection structures produced in vitro. A total of 31 different in planta-induced genes (PIGs) were identified. Some of the PIGs are highly expressed in haustoria. The PIGs are single or low copy number genes in the rust genome. A variety of developmentally regulated expression patterns of PIG mRNAs were observed. Sequence analysis of PIG cDNAs revealed similarities to genes encoding proteins involved in amino acid transport, thiamine biosynthesis, short-chain dehydrogenases, metallothioneins, cytochrome P-450 monooxygenases, and peptidyl-prolyl isomerases. PMID:9150592

Hahn, M; Mendgen, K

1997-05-01

55

Unfolding of in planta activity of anti-rep ribozyme in presence of a RNA silencing suppressor.  

PubMed

Antisense RNA ribozymes have intrinsic endonucleolytic activity to effect cleavage of the target RNA. However, this activity in vivo is often controlled by the dominance of antisense or other double-stranded RNA mechanism. In this work, we demonstrate the in planta activity of a hammerhead ribozyme designed to target rep-mRNA of a phytopathogen Mungbean Yellow Mosaic India virus (MYMIV) as an antiviral agent. We also found RNA-silencing is induced on introduction of catalytically active as well as inactive ribozymes. Using RNA-silencing suppressors (RSS), we demonstrate that the endonucleolytic activity of ribozymes is a true phenomenon, even while a mutated version may demonstrate a similar down-regulation of the target RNA. This helps to ease the confusion over the action mechanism of ribozymes in vivo. PMID:24735726

Mishra, Sumona Karjee; Chilakamarthi, Ushasri; Deb, J K; Mukherjee, Sunil Kumar

2014-05-21

56

Plastid-localized amino acid biosynthetic pathways of Plantae are predominantly composed of non-cyanobacterial enzymes  

PubMed Central

Studies of photosynthetic eukaryotes have revealed that the evolution of plastids from cyanobacteria involved the recruitment of non-cyanobacterial proteins. Our phylogenetic survey of >100 Arabidopsis nuclear-encoded plastid enzymes involved in amino acid biosynthesis identified only 21 unambiguous cyanobacterial-derived proteins. Some of the several non-cyanobacterial plastid enzymes have a shared phylogenetic origin in the three Plantae lineages. We hypothesize that during the evolution of plastids some enzymes encoded in the host nuclear genome were mistargeted into the plastid. Then, the activity of those foreign enzymes was sustained by both the plastid metabolites and interactions with the native cyanobacterial enzymes. Some of the novel enzymatic activities were favored by selective compartmentation of additional complementary enzymes. The mosaic phylogenetic composition of the plastid amino acid biosynthetic pathways and the reduced number of plastid-encoded proteins of non-cyanobacterial origin suggest that enzyme recruitment underlies the recompartmentation of metabolic routes during the evolution of plastids.

Reyes-Prieto, Adrian; Moustafa, Ahmed

2012-01-01

57

Behavior of RNAi suppressor protein 2b of Cucumber mosaic virus in planta in presence and absence of virus.  

PubMed

The 2b protein encoded by Cucumber mosaic virus (CMV) has been shown as a virus counter defense factor that interferes with the RNAi pathway. The 2b gene from CMV-banana, New Delhi isolate (CMV-NDLS) was amplified from CMV infected cucumber plants to generate the sense and antisense binary vector constructs for 2b expression and repression in planta. Constitutive expression of 2b gene in healthy Nicotiana tabacum caused phenotypic aberrations during somatic embryogenesis, which were not observed when expressed in CMV infected N. tabacum. Further, the established virus population in CMV infected N. tabacum was not affected by constitutive expression and repression of 2b gene. Thus, indicating its role in initiation of gene silencing, at the early stage of viral infection. This is the first demonstration of differential behavior of 2b suppressor protein in host development in the absence and presence of virus. PMID:18438704

Praveen, Shelly; Mangrauthia, Satendra K; Singh, Priyanka; Mishra, Anil K

2008-08-01

58

Development of fiber optic spectroscopy for in-vitro and in-planta detection of fluorescent proteins  

NASA Astrophysics Data System (ADS)

The objective of this project is to apply photonics technology to bio-safety management of genetically modified (GM) plants. The conventional method for screening GM plants is through selection using antibiotic resistance markers. There is public concern with such approaches and these are associated with food safety issues, escape of antibiotic resistance genes to pathogenic microorganisms and interference with antibiotic therapy. Thus, the strategy taken in this project is to replace antibiotic resistance markers with fluorescent protein markers that allow for rapid and non-invasive optical screening of genetically modified plants. In this paper, fibre optic spectroscopy was developed to detect and quantify recombinant green (EGFP) and red (DsRED) fluorescent proteins in vitro and in planta. In vitro detection was first carried out to optimize the sensitivity of the optical system. The bacterial expression vectors carrying the coding regions of EGFP and DsRED were introduced into Escherichia coli host cells and fluorescent proteins were produced following induction with IPTG. Soluble EGFP and DsRED proteins were isolated from lysed bacterial cells and serially diluted for quantitative analysis by fibre optic spectroscopy using different light sources, namely, blue LED (475 nm), tungsten halogen (350 - 1000 nm) and double frequency Nd:YAG green laser (532 nm). Fluorescence near the expected emission wavelengths could be detected up to 320X dilution for EGFP and DsRED with blue LED and 532 nm green laser, respectively, as the excitation source. Tungsten halogen was found to be unsuitable for excitation of both EGFP and DsRED. EGFP was successfully purified by size separation under non-denaturing electrophoretic conditions and quantified. The minimum concentration of EGFP detectable with blue LED excitation was 5 mg/ml. To determine the capability of spectroscopy detection in planta, transgenic potato hairy roots and whole modified plant lines expressing the fluorescent markers were regenerated. T

Liew, Oi Wah; Chen, Jun-Wei; Asundi, Anand K.

2001-10-01

59

Roquefortine/oxaline biosynthesis pathway metabolites in Penicillium ser. Corymbifera: in planta production and implications for competitive fitness.  

PubMed

Three strains of each of the seven taxa comprising the Penicillium series Corymbifera were surveyed by direct injection mass spectrometry (MS) and liquid chromatography-MS for the production of terrestric acid and roquefortine/oxaline biosynthesis pathway metabolites when cultured upon macerated tissue agars prepared from Allium cepa, Zingiber officinale, and Tulipa gesneriana, and on the defined medium Czapek yeast autolysate agar (CYA). A novel solid-phase extraction methodology was applied for the rapid purification of roquefortine metabolites from a complex matrix. Penicillium hordei and P. venetum produced roquefortine D and C, whereas P. hirsutum produced roquefortine D and C and glandicolines A and B. P. albocoremium, P. allii, and P. radicicola carried the pathway through to meleagrin, producing roquefortine D and C, glandicolines A and B, and meleagrin. P. tulipae produced all previously mentioned metabolites yet carried the pathway through to an end product recognized as epi-neoxaline, prompting the proposal of a roquefortine/epi-neoxaline biogenesis pathway. Terrestric acid production was stimulated by all Corymbifera strains on plant-derived media compared to CYA controls. In planta, production of terrestric acid, roquefortine C, glandicolines A and B, meleagrin, epi-neoxaline, and several other species-related secondary metabolites were confirmed from A. cepa bulbs infected with Corymbifera strains. The deposition of roquefortine/oxaline pathway metabolites as an extracellular nitrogen reserve for uptake and metabolism into growing mycelia and the synergistic role of terrestric acid and other Corymbifera secondary metabolites in enhancing the competitive fitness of Corymbifera species in planta are proposed. PMID:16195849

Overy, D P; Nielsen, K F; Smedsgaard, J

2005-10-01

60

The small subunit of snapdragon geranyl diphosphate synthase modifies the chain length specificity of tobacco geranylgeranyl diphosphate synthase in planta.  

PubMed

Geranyl diphosphate (GPP), the precursor of many monoterpene end products, is synthesized in plastids by a condensation of dimethylallyl diphosphate and isopentenyl diphosphate (IPP) in a reaction catalyzed by homodimeric or heterodimeric GPP synthase (GPPS). In the heterodimeric enzymes, a noncatalytic small subunit (GPPS.SSU) determines the product specificity of the catalytic large subunit, which may be either an active geranylgeranyl diphosphate synthase (GGPPS) or an inactive GGPPS-like protein. Here, we show that expression of snapdragon (Antirrhinum majus) GPPS.SSU in tobacco (Nicotiana tabacum) plants increased the total GPPS activity and monoterpene emission from leaves and flowers, indicating that the introduced catalytically inactive GPPS.SSU found endogenous large subunit partner(s) and formed an active snapdragon/tobacco GPPS in planta. Bimolecular fluorescence complementation and in vitro enzyme analysis of individual and hybrid proteins revealed that two of four GGPPS-like candidates from tobacco EST databases encode bona fide GGPPS that can interact with snapdragon GPPS.SSU and form a functional GPPS enzyme in plastids. The formation of chimeric GPPS in transgenic plants also resulted in leaf chlorosis, increased light sensitivity, and dwarfism due to decreased levels of chlorophylls, carotenoids, and gibberellins. In addition, these transgenic plants had reduced levels of sesquiterpene emission, suggesting that the export of isoprenoid intermediates from the plastids into the cytosol was decreased. These results provide genetic evidence that GPPS.SSU modifies the chain length specificity of phylogenetically distant GGPPS and can modulate IPP flux distribution between GPP and GGPP synthesis in planta. PMID:20028839

Orlova, Irina; Nagegowda, Dinesh A; Kish, Christine M; Gutensohn, Michael; Maeda, Hiroshi; Varbanova, Marina; Fridman, Eyal; Yamaguchi, Shinjiro; Hanada, Atsushi; Kamiya, Yuji; Krichevsky, Alexander; Citovsky, Vitaly; Pichersky, Eran; Dudareva, Natalia

2009-12-01

61

cis-Prenyltransferase atCPT6 produces a family of very short-chain polyisoprenoids in planta.  

PubMed

cis-Prenyltransferases (CPTs) comprise numerous enzymes synthesizing isoprenoid hydrocarbon skeleton with isoprenoid units in the cis (Z) configuration. The chain-length specificity of a particular plant CPT is in most cases unknown despite thecomposition of the accumulated isoprenoids in the tissue of interest being well established. In this report AtCPT6, one of the nine Arabidopsis thaliana CPTs, is shown to catalyze the synthesis of a family of very short-chain polyisoprenoid alcohols of six, seven, and eight isoprenoid units, those of seven units dominating The product specificity of AtCPT6 was established in vivo following its expression in the heterologous system of the yeast Saccharomyces cerevisiae and was confirmed by the absence of specific products in AtCPT6 T-DNA insertion mutants and their overaccumulation in AtCPT6-overexpressing plants. These observations are additionally validated in silico using an AtCPT6 model obtained by homology modeling. AtCPT6 only partially complements the function of the yeast homologue of CPT-Rer2 since it restores the growth but not protein glycosylation in rer2delta yeast.This is the first in planta characterization of specific products of a plant CPT producing polyisoprenoids. Their distribution suggests that a joint activity of several CPTs is required to produce the complex mixture of polyisoprenoid alcohols found in Arabidopsis roots. PMID:24291644

Surmacz, Liliana; Plochocka, Danuta; Kania, Magdalena; Danikiewicz, Witold; Swiezewska, Ewa

2014-02-01

62

In planta stage-specific fungal gene profiling elucidates the molecular strategies of Fusarium graminearum growing inside wheat coleoptiles.  

PubMed

The ascomycete Fusarium graminearum is a destructive fungal pathogen of wheat (Triticum aestivum). To better understand how this pathogen proliferates within the host plant, we tracked pathogen growth inside wheat coleoptiles and then examined pathogen gene expression inside wheat coleoptiles at 16, 40, and 64 h after inoculation (HAI) using laser capture microdissection and microarray analysis. We identified 344 genes that were preferentially expressed during invasive growth in planta. Gene expression profiles for 134 putative plant cell wall-degrading enzyme genes suggest that there was limited cell wall degradation at 16 HAI and extensive degradation at 64 HAI. Expression profiles for genes encoding reactive oxygen species (ROS)-related enzymes suggest that F. graminearum primarily scavenges extracellular ROS before a later burst of extracellular ROS is produced by F. graminearum enzymes. Expression patterns of genes involved in primary metabolic pathways suggest that F. graminearum relies on the glyoxylate cycle at an early stage of plant infection. A secondary metabolite biosynthesis gene cluster was specifically induced at 64 HAI and was required for virulence. Our results indicate that F. graminearum initiates infection of coleoptiles using covert penetration strategies and switches to overt cellular destruction of tissues at an advanced stage of infection. PMID:23266949

Zhang, Xiao-Wei; Jia, Lei-Jie; Zhang, Yan; Jiang, Gang; Li, Xuan; Zhang, Dong; Tang, Wei-Hua

2012-12-01

63

In planta effector competition assays detect Hyaloperonospora arabidopsidis effectors that contribute to virulence and localize to different plant subcellular compartments.  

PubMed

The genome of the pathogenic oomycete Hyaloperonospora arabidopsidis is predicted to encode at least 134 high-confidence effectors (HaRxL) carrying the RxLR motif implicated in their translocation into plant cells. However, only four avirulence genes (ATR1, ATR13, ATR5, and ATR39) have been isolated. This indicates that identification of HaRxL effectors based on avirulence is low throughput. We aimed at rapidly identifying H. arabidopsidis effectors that contribute to virulence by developing methods to detect and quantify multiple candidates in bacterial mixed infections using either Illumina sequencing or capillary electrophoresis. In these assays, referred to here as in planta effector competition assays, we estimate the contribution to virulence of individual effectors by calculating the abundance of each HaRxL in the bacterial population recovered from leaves 3 days after inoculation relative to abundance in the initial mixed inoculum. We identified HaRxL that enhance Pseudomonas syringae pv. tomato DC3000 growth in some but not all Arabidopsis accessions. Further analysis showed that HaRxLL464, HaRxL75, HaRxL22, HaRxLL441, and HaRxL89 suppress pathogen-associated molecular pattern-triggered immunity (PTI) and localize to different subcellular compartments in Nicotiana benthamiana, providing evidence for a multilayered suppression of PTI by pathogenic oomycetes and molecular probes for the dissection of PTI. PMID:23734779

Badel, Jorge Luis; Piquerez, Sophie J M; Greenshields, David; Rallapalli, Ghanasyam; Fabro, Georgina; Ishaque, Naveed; Jones, Jonathan D G

2013-07-01

64

Agrobacterium tumefaciens Deploys a Superfamily of Type VI Secretion DNase Effectors as Weapons for Interbacterial Competition In Planta.  

PubMed

The type VI secretion system (T6SS) is a widespread molecular weapon deployed by many Proteobacteria to target effectors/toxins into both eukaryotic and prokaryotic cells. We report that Agrobacterium tumefaciens, a soil bacterium that triggers tumorigenesis in plants, produces a family of type VI DNase effectors (Tde) that are distinct from previously known polymorphic toxins and nucleases. Tde exhibits an antibacterial DNase activity that relies on a conserved HxxD motif and can be counteracted by a cognate immunity protein, Tdi. In vitro, A. tumefaciens T6SS could kill Escherichia coli but triggered a lethal counterattack by Pseudomonas aeruginosa upon injection of the Tde toxins. However, in an in planta coinfection assay, A. tumefaciens used Tde effectors to attack both siblings cells and P. aeruginosa to ultimately gain a competitive advantage. Such acquired T6SS-dependent fitness in vivo and conservation of Tde-Tdi couples in bacteria highlights a widespread antibacterial weapon beneficial for niche colonization. PMID:24981331

Ma, Lay-Sun; Hachani, Abderrahman; Lin, Jer-Sheng; Filloux, Alain; Lai, Erh-Min

2014-07-01

65

Agrobacterium tumefaciens Deploys a Superfamily of Type VI Secretion DNase Effectors as Weapons for Interbacterial Competition In Planta  

PubMed Central

Summary The type VI secretion system (T6SS) is a widespread molecular weapon deployed by many Proteobacteria to target effectors/toxins into both eukaryotic and prokaryotic cells. We report that Agrobacterium tumefaciens, a soil bacterium that triggers tumorigenesis in plants, produces a family of type VI DNase effectors (Tde) that are distinct from previously known polymorphic toxins and nucleases. Tde exhibits an antibacterial DNase activity that relies on a conserved HxxD motif and can be counteracted by a cognate immunity protein, Tdi. In vitro, A. tumefaciens T6SS could kill Escherichia coli but triggered a lethal counterattack by Pseudomonas aeruginosa upon injection of the Tde toxins. However, in an in planta coinfection assay, A. tumefaciens used Tde effectors to attack both siblings cells and P. aeruginosa to ultimately gain a competitive advantage. Such acquired T6SS-dependent fitness in vivo and conservation of Tde-Tdi couples in bacteria highlights a widespread antibacterial weapon beneficial for niche colonization.

Ma, Lay-Sun; Hachani, Abderrahman; Lin, Jer-Sheng; Filloux, Alain; Lai, Erh-Min

2014-01-01

66

Cloning and characterization of pl1 encoding an in planta-secreted pectate lyase of Fusarium oxysporum.  

PubMed

A pectate lyase (PL1) from the tomato vascular wilt pathogen Fusarium oxysporum f.sp. lycopersici was previously characterized, and evidence was obtained for its production in planta. The gene encoding PL1 was isolated from a genomic library of F. oxysporum f. sp. lycopersici. Pl1 encodes a 240 amino-acid polypeptide with one putative N-glycosylation site and a 15 amino-acid N-terminal signal peptide. PL1 showed 89%, 67%, 55% and 56% identity with the products of the Fusarium solani f.sp. pisi pelA, pelB, pelC and pelD genes, respectively. A single copy of the gene was detected in different formae speciales of F. oxysporum. The pl1 transcript was observed during growth on polygalacturonic acid sodium salt and tomato vascular tissue, but not on pectin or glucose. RT-PCR showed pl1 expression in roots and stems of tomato plants infected by F. oxysporum f.sp. lycopersici. PMID:10022947

Huertas-González, M D; Ruiz-Roldán, M C; García Maceira, F I; Roncero, M I; Di Pietro, A

1999-02-01

67

Overexpression of the rice carotenoid cleavage dioxygenase 1 gene in Golden Rice endosperm suggests apocarotenoids as substrates in planta.  

PubMed

Carotenoids are converted by carotenoid cleavage dioxygenases that catalyze oxidative cleavage reactions leading to apocarotenoids. However, apocarotenoids can also be further truncated by some members of this enzyme family. The plant carotenoid cleavage dioxygenase 1 (CCD1) subfamily is known to degrade both carotenoids and apocarotenoids in vitro, leading to different volatile compounds. In this study, we investigated the impact of the rice CCD1 (OsCCD1) on the pigmentation of Golden Rice 2 (GR2), a genetically modified rice variety accumulating carotenoids in the endosperm. For this purpose, the corresponding cDNA was introduced into the rice genome under the control of an endosperm-specific promoter in sense and anti-sense orientations. Despite high expression levels of OsCCD1 in sense plants, pigment analysis revealed carotenoid levels and patterns comparable to those of GR2, pleading against carotenoids as substrates in rice endosperm. In support, similar carotenoid contents were determined in anti-sense plants. To check whether OsCCD1 overexpressed in GR2 endosperm is active, in vitro assays were performed with apocarotenoid substrates. HPLC analysis confirmed the cleavage activity of introduced OsCCD1. Our data indicate that apocarotenoids rather than carotenoids are the substrates of OsCCD1 in planta. PMID:20549230

Ilg, Andrea; Yu, Qiuju; Schaub, Patrick; Beyer, Peter; Al-Babili, Salim

2010-08-01

68

Construction of EGFP-labeling system for visualizing the infection process of Xanthomonas axonopodis pv. citri in planta.  

PubMed

Xanthomonas axonopodis pv. citri (Xac) is the causal agent of citrus bacterial canker, an economically important disease to world citrus industry. To monitor the infection process of Xac in different citrus plants, the enhanced green florescent protein (EGFP) visualizing system was constructed to visualize the propagation and localization in planta. First, the wild-type Xac was isolated from the diseased leaves of susceptible 'Bingtang' sweet orange, and then the isolated Xac was labeled with EGFP by triparental mating. After PCR identification, the growth kinetics and pathogenicity of the transformants were analyzed in comparison with the wild-type Xac. The EGFP-labeled bacteria were inoculated by spraying on the surface and infiltration in the mesophyll of 'Bingtang' sweet orange leaves. The bacterial cell multiplication and diffusion processes were observed directly under confocal laser scanning microscope at different intervals after inoculation. The results indicated that the EGFP-labeled Xac releasing clear green fluorescence light under fluorescent microscope showed the infection process and had the same pathogenicity as the wild type to citrus. Consequently, the labeled Xac demonstrated the ability as an efficient tool to monitor the pathogen infection. PMID:22674174

Liu, Li-Ping; Deng, Zi-Niu; Qu, Jin-Wang; Yan, Jia-Wen; Catara, Vittoria; Li, Da-Zhi; Long, Gui-You; Li, Na

2012-09-01

69

An anatomic study of the quadratus plantae in relation to tendinous slips of the flexor hallucis longus for gait analysis.  

PubMed

The aim of this study was to demonstrate the morphology of the quadratus plantae (QP) in relation to the tendinous slips of the flexor hallucis longus (FHL) and their surrounding structures, thereby providing data to understand function of the QP during gait, and for analyzing the movements of the foot and designing postoperative rehabilitation programs. The QP was investigated in 50 specimens of embalmed adult cadavers. The QP inserted into the tendon of the flexor digitorum longus (FDL) and the tendinous slips of the FHL in 96%, and only to the tendon of the FDL in 4%. The tendinous slip of the FHL targeted the tendon for the second toe in 4 of the 50 specimens (8%). The tendinous slip divided into two separate slips to the tendons for the second and third toes in 32 specimens (64%), and for the second, third, and fourth toes in 14 specimens (28%). Thus, the tendon and tendinous slips of the FHL may distribute the load of the great toe to the second toe to the third or fourth toe in the forefoot, especially during toe-off. In addition, the main attachment of the QP to the tendinous slips of the FHL may provide more efficient control of the long flexor tendons in comparison with that of the QP to the tendon of the FDL. PMID:21812033

Hur, Mi-Sun; Kim, Jae-Hyoun; Woo, Jung-Su; Choi, Byoung-Young; Kim, Hee-Jin; Lee, Kyu-Seok

2011-09-01

70

Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology  

PubMed Central

Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus of crop biofortification, phytoremediation, and food security research. This paper focuses on the potential for advancing plant metal(loid) research by combining molecular biology and synchrotron-based techniques. Recent advances in x-ray focussing optics and fluorescence detection have greatly improved the potential of synchrotron techniques for plant science research, allowing metal(loids) to be imaged in vivo in hydrated plant tissues at sub-micron resolution. Laterally resolved metal(loid) speciation can also be determined. By using molecular techniques to probe the location of gene expression and protein localisation and combining it with this synchrotron-derived data, functional information can be effectively and efficiently assigned to specific genes. This paper provides a review of the state of the art in this field, and provides examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta.

Donner, Erica; Punshon, Tracy; Guerinot, Mary Lou; Lombi, Enzo

2013-01-01

71

EL PARADIGMA DE LOS DELITOS DE TERRORISMO ENTRE DERECHO INTERNO Y DERECHO INTERNACIONAL  

Microsoft Academic Search

El artículo busca establecer un panorama entre los delitos de terrorismo desde su surgimiento hasta los días de hoy, teniendo en cuenta el desarrollo entre las aquí clasificadas fases evolutivas del fenómeno terrorista, llegando por fin a la última etapa, el terrorismo hoy que si conoce como, antes y después de los atentados de 11 de septiembre. Frente a esto

Ignácio Nunes Fernandes

2011-01-01

72

Depositación polínica anual en el Parque Nacional Pre-Delta, Entre Ríos, Argentina  

Microsoft Academic Search

Annual pollen deposition in the Pre-Delta National Park (Entre Ríos, Argentina). This work aims to analyze the seasonal pattern and the diversity of the Pre-Delta National Park vegetation (Entre Ríos, Argentina) as reflected by the deposited pollen along a year. Pollen has been monitored monthly with Tauber traps over one year (since August 2004 to July 2005). The pollen traps

Fabiana LATORRE; Marta A. CACCAVARI

73

La baisse des charges en France : Un bon compromis entre emploi et productivité  

Microsoft Academic Search

Nous proposons une maquette du marché du travail à tems complet sur le segment des moins qualifiés, tenant compte des interdépendances entre offre et demande de travail et dans laquelle les distributions de salaire et de productivité sont endogènes, résultat d’un jeu stratégique entre entreprises. La reproduction de la distribution observée des salaires nous permet d’identifier précisément les paramètres structurels

Jean-Olivier Hairault; François Langot

2005-01-01

74

Réforme de la Pac, accords au Gatt : quelles incidences sur les transferts financiers entre les Douze  

Microsoft Academic Search

[spa] Reforma de la Pac, acuerdos Gatt : cuáles son las incidencias sobre las transferencias financieres entre los Doce, . por Eve Fouilleux.. . La reforma de la Política agrícola común y los acuerdos sobre el aspecto agrícola del Gatt modifican el reparte de las ventajas financieras de adhesión al mercado común agrícola entre los Doce. El modelo Erpac de

Eve Fouilleux

1995-01-01

75

Identification of Epichlo? Endophytes In Planta by a Microsatellite-Based PCR Fingerprinting Assay with Automated Analysis  

PubMed Central

Epichloë endophytes are a group of filamentous fungi that include both sexual (Epichloë) and asexual (Neotyphodium) species. As a group they are genetically diverse and form both antagonistic and mutualistic associations with temperate grasses. We report here on the development of a microsatellite-based PCR system for fingerprinting this group of fungi with template isolated from either culture or infected plant material. M13mp19 partial genomic libraries were constructed for size-fractionated genomic DNA from two endophyte strains. These libraries were screened with a mixture of DIG-labeled dinucleotide and trinucleotide repeat probes. Positive clones were sequenced, and nine unique microsatellite loci were identified. An additional microsatellite was serendipitously identified in the 3? untranscribed region of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase gene from N. lolii Lp19. Primers were designed for each locus and a panel of endophytes, from different taxonomic groupings, was screened to determine the degree of polymorphism. On the basis of these results a multiplex assay was developed for strain identification with fluorescently labeled primers for five of these loci. Using this system the size of the products amplified can be precisely determined by automated analysis, and an allele profile for each strain can be readily generated. The assay was shown to resolve endophyte groupings to the level of known isozyme phenotype groupings. In a blind test the assay was used successfully to identify a set of endophytes in planta. A reference database of allele sizes has been established for the panel of endophytes examined, and this will be expanded as new strains are analyzed.

Moon, Christina D.; Tapper, Brian A.; Scott, Barry

1999-01-01

76

In planta analysis of a cis-regulatory cytokinin response motif in Arabidopsis and identification of a novel enhancer sequence.  

PubMed

The phytohormone cytokinin plays a key role in regulating plant growth and development, and is involved in numerous physiological responses to environmental changes. The type-B response regulators, which regulate the transcription of cytokinin response genes, are a part of the cytokinin signaling system. Arabidopsis thaliana encodes 11 type-B response regulators (type-B ARRs), and some of them were shown to bind in vitro to the core cytokinin response motif (CRM) 5'-(A/G)GAT(T/C)-3' or, in the case of ARR1, to an extended motif (ECRM), 5'-AAGAT(T/C)TT-3'. Here we obtained in planta proof for the functionality of the latter motif. Promoter deletion analysis of the primary cytokinin response gene ARR6 showed that a combination of two extended motifs within the promoter is required to mediate the full transcriptional activation by ARR1 and other type-B ARRs. CRMs were found to be over-represented in the vicinity of ECRMs in the promoters of cytokinin-regulated genes, suggesting their functional relevance. Moreover, an evolutionarily conserved 27 bp long T-rich region between -220 and -193 bp was identified and shown to be required for the full activation by type-B ARRs and the response to cytokinin. This novel enhancer is not bound by the DNA-binding domain of ARR1, indicating that additional proteins might be involved in mediating the transcriptional cytokinin response. Furthermore, genome-wide expression profiling identified genes, among them ARR16, whose induction by cytokinin depends on both ARR1 and other specific type-B ARRs. This together with the ECRM/CRM sequence clustering indicates cooperative action of different type-B ARRs for the activation of particular target genes. PMID:23620480

Ramireddy, Eswarayya; Brenner, Wolfram G; Pfeifer, Andreas; Heyl, Alexander; Schmülling, Thomas

2013-07-01

77

Effective and specific in planta RNAi in cyst nematodes: expression interference of four parasitism genes reduces parasitic success  

PubMed Central

Cyst nematodes are highly evolved sedentary plant endoparasites that use parasitism proteins injected through the stylet into host tissues to successfully parasitize plants. These secretory proteins likely are essential for parasitism as they are involved in a variety of parasitic events leading to the establishment of specialized feeding cells required by the nematode to obtain nourishment. With the advent of RNA interference (RNAi) technology and the demonstration of host-induced gene silencing in parasites, a new strategy to control pests and pathogens has become available, particularly in root-knot nematodes. Plant host-induced silencing of cyst nematode genes so far has had only limited success but similarly should disrupt the parasitic cycle and render the host plant resistant. Additional in planta RNAi data for cyst nematodes are being provided by targeting four parasitism genes through host-induced RNAi gene silencing in transgenic Arabidopsis thaliana, which is a host for the sugar beet cyst nematode Heterodera schachtii. Here it is reported that mRNA abundances of targeted nematode genes were specifically reduced in nematodes feeding on plants expressing corresponding RNAi constructs. Furthermore, this host-induced RNAi of all four nematode parasitism genes led to a reduction in the number of mature nematode females. Although no complete resistance was observed, the reduction of developing females ranged from 23% to 64% in different RNAi lines. These observations demonstrate the relevance of the targeted parasitism genes during the nematode life cycle and, potentially more importantly, suggest that a viable level of resistance in crop plants may be accomplished in the future using this technology against cyst nematodes.

Sindhu, Anoop S.; Maier, Tom R.; Mitchum, Melissa G.; Hussey, Richard S.; Davis, Eric L.; Baum, Thomas J.

2009-01-01

78

Riqueza de plantas vasculares  

Microsoft Academic Search

Vascular plant diversity (excluding pteridophytes) was analyzed for the countries of Ecuador, Peru, and Bolivia from information available in TROPICOS. A total of 34,286 species were registered for the three countries, distributed in 256 families and 3,309 genera. Peru is the most diverse of the three countries. Orchidaceae, Asteraceae and Fabaceae were the three most diverse families of the region.

Peter M. Jørgensen; Carmen Ulloa; Carla Maldonado

79

Requirement of the galU gene for polysaccharide production by and pathogenicity and growth In Planta of Xanthomonas citri subsp. citri.  

PubMed

Xanthomonas citri subsp. citri is the causal agent of citrus canker, which has a significant impact on citrus production. In this study, we characterized the galU gene of X. citri subsp. citri. Two galU mutants (F6 and D12) were identified in an X. citri subsp. citri EZ-Tn5 Tnp transposon library. Rescue cloning, sequence analysis, and Southern blot analysis indicated that both of these mutants had a single copy of the EZ-Tn5 transposon inserted in galU in the chromosome. Further study showed that galU was required for biosynthesis of extracellular polysaccharides (EPS; xanthan gum) and capsular polysaccharide (CPS) and biofilm formation. Mutation of galU resulted in a loss of pathogenicity for grapefruit. The loss of pathogenicity of a galU mutant resulted from its inability to grow in planta rather than from the effect on virulence genes. Quantitative reverse transcription-PCR assays indicated that mutation of galU did not impair the expression of key virulence genes, such as pthA of X. citri subsp. citri. Although D12 had a growth rate similar to that of the wild-type strain in nutrient broth, no D12 population became established in the intercellular spaces of citrus leaves. Coinoculation of a galU mutant with the wild-type strain did not promote growth of the galU mutant in planta. Defects in EPS and CPS production, pathogenicity, and growth in planta of the galU mutant were complemented to the wild-type level using plasmid pCGU2.1 containing an intact galU gene. These data indicate that the galU gene contributes to X. citri subsp. citri growth in intercellular spaces and is involved in EPS and CPS synthesis and biofilm formation. PMID:20118360

Guo, Yinping; Sagaram, Uma Shankar; Kim, Jeong-soon; Wang, Nian

2010-04-01

80

Bikinin-like inhibitors targeting GSK3/Shaggy-like kinases: characterisation of novel compounds and elucidation of their catabolism in planta  

PubMed Central

Background Plant GSK-3/Shaggy-like kinases are key players in brassinosteroid (BR) signalling which impact on plant development and participate in response to wounding, pathogens and salt stress. Bikinin was previously identified in a chemical genetics screen as an inhibitor targeting these kinases. To dissect the structural elements crucial for inhibition of GSK-3/Shaggy-like kinases by bikinin and to isolate more potent compounds we synthesised a number of related substances and tested their inhibitory activity in vitro and in vivo using Arabidopsis thaliana. Results A pyridine ring with an amido succinic acid residue in position 2 and a halogen in position 5 were crucial for inhibitory activity. The compound with an iodine substituent in position 5, denoted iodobikinin, was most active in inhibiting BIN2 activity in vitro and efficiently induced brassinosteroid-like responses in vivo. Its methyl ester, methyliodobikinin, showed improved cell permeability, making it highly potent in vivo although it had lower activity in vitro. HPLC analysis revealed that the methyl residue was rapidly cleaved off in planta liberating active iodobikinin. In addition, we provide evidence that iodobikinin and bikinin are inactivated in planta by conjugation with glutamic acid or malic acid and that the latter process is catalysed by the malate transferase SNG1. Conclusion Brassinosteroids participate in regulation of many aspects of plant development and in responses to environmental cues. Thus compounds modulating their action are valuable tools to study such processes and may be an interesting opportunity to modify plant growth and performance in horticulture and agronomy. Here we report the development of bikinin derivatives with increased potency that can activate BR signalling and mimic BR action. Methyliodobikinin was 3.4 times more active in vivo than bikinin. The main reason for the superior activity of methyliodobikinin, the most potent compound, is its enhanced plant tissue permeability. Inactivation of bikinin and its derivatives in planta involves SNG1, which constitutes a novel pathway for modification of xenobiotic compounds.

2014-01-01

81

In planta production of two peptides of the Classical Swine Fever Virus (CSFV) E2 glycoprotein fused to the coat protein of potato virus X  

PubMed Central

Background Classical Swine Fever (CSFV) is one of the most important viral infectious diseases affecting wild boars and domestic pigs. The etiological agent of the disease is the CSF virus, a single stranded RNA virus belonging to the family Flaviviridae. All preventive measures in domestic pigs have been focused in interrupting the chain of infection and in avoiding the spread of CSFV within wild boars as well as interrupting transmission from wild boars to domestic pigs. The use of plant based vaccine against CSFV would be advantageous as plant organs can be distributed without the need of particular treatments such as refrigeration and therefore large areas, populated by wild animals, could be easily covered. Results We report the in planta production of peptides of the classical swine fever (CSF) E2 glycoprotein fused to the coat protein of potato virus X. RT-PCR studies demonstrated that the peptide encoding sequences are correctly retained in the PVX construct after three sequential passage in Nicotiana benthamiana plants. Sequence analysis of RT-PCR products confirmed that the epitope coding sequences are replicated with high fidelity during PVX infection. Partially purified virions were able to induce an immune response in rabbits. Conclusion Previous reports have demonstrated that E2 synthetic peptides can efficiently induce an immunoprotective response in immunogenized animals. In this work we have showed that E2 peptides can be expressed in planta by using a modified PVX vector. These results are particularly promising for designing strategies for disease containment in areas inhabited by wild boars.

Marconi, Gianpiero; Albertini, Emidio; Barone, Pierluigi; De Marchis, Francesca; Lico, Chiara; Marusic, Carla; Rutili, Domenico; Veronesi, Fabio; Porceddu, Andrea

2006-01-01

82

La problematica de la demarcacion entre ciencia y pseudociencia y sus implicaciones en la educacion cientifica  

NASA Astrophysics Data System (ADS)

En la sociedad prevalece una tendencia generalizada hacia la inclusion de creencias y practicas pseudocientificas. Esta investigacion responde a la necesidad de analizar como la proliferacion de las pseudociencias afecta la vision que tienen los estudiantes universitarios sobre las ciencias naturales. A tales efectos, la investigadora describe las concepciones epistemologicas que tienen los estudiantes sobre las ciencias y las pseudociencias e identifica los criterios de demarcacion, entre un area y otra, que se derivan de estas concepciones. De igual modo, esta identifica las creencias y practicas pseudocientificas de mayor arraigo entre los estudiantes, destacando, a su vez, la razon de ser de las mismas. Por ultimo, la investigadora analiza las implicaciones educativas de la problematica de la demarcacion entre ciencia y pseudociencia. La investigacion es de naturaleza mixta, enmarcada en los paradigmas empirico- analitico y cualitativo. El proceso investigativo se llevo a cabo mediante la administracion del cuestionario Criterios para la demarcacion entre ciencia y pseudociencia. La parte cualitativa estuvo enmarcada en el diseno de estudio de caso, recopilando informacion mediante entrevistas semiestructuradas en dos grupos focales. La poblacion de estudio estuvo constituida por estudiantes universitarios del nivel subgraduado de la Universidad Central de Bayamon. Los resultados del estudio reflejaron las concepciones erroneas de los estudiantes sobre la naturaleza de las ciencias y las pseudociencias. Con respecto a la demarcacion entre ciencia y pseudociencia, el criterio imperante entre los universitarios es el de la verificabilidad, considerando la aplicacion del metodo cientifico como el metodo para demostrar la veracidad de las teorias cientificas. Las creencias y practicas pseudocientificas no son muy frecuentes entre los universitarios. Estos atribuyen las mismas a la prevalencia de elementos supersticiosos y al engano a que es sometida la poblacion por quienes promueven estas practicas. A partir de los resultados, la investigadora concluye que la problematica sobre la demarcacion entre ciencia y pseudociencia esta influenciada por unos procesos de ensenanza enfocados en una vision distorsionada de la ciencia, producto de la no integracion de los aspectos filosoficos, historicos y sociales de la misma.

Jimenez Tolentino, Dinorah

83

The Small Subunit of Snapdragon Geranyl Diphosphate Synthase Modifies the Chain Length Specificity of Tobacco Geranylgeranyl Diphosphate Synthase in Planta[W  

PubMed Central

Geranyl diphosphate (GPP), the precursor of many monoterpene end products, is synthesized in plastids by a condensation of dimethylallyl diphosphate and isopentenyl diphosphate (IPP) in a reaction catalyzed by homodimeric or heterodimeric GPP synthase (GPPS). In the heterodimeric enzymes, a noncatalytic small subunit (GPPS.SSU) determines the product specificity of the catalytic large subunit, which may be either an active geranylgeranyl diphosphate synthase (GGPPS) or an inactive GGPPS-like protein. Here, we show that expression of snapdragon (Antirrhinum majus) GPPS.SSU in tobacco (Nicotiana tabacum) plants increased the total GPPS activity and monoterpene emission from leaves and flowers, indicating that the introduced catalytically inactive GPPS.SSU found endogenous large subunit partner(s) and formed an active snapdragon/tobacco GPPS in planta. Bimolecular fluorescence complementation and in vitro enzyme analysis of individual and hybrid proteins revealed that two of four GGPPS-like candidates from tobacco EST databases encode bona fide GGPPS that can interact with snapdragon GPPS.SSU and form a functional GPPS enzyme in plastids. The formation of chimeric GPPS in transgenic plants also resulted in leaf chlorosis, increased light sensitivity, and dwarfism due to decreased levels of chlorophylls, carotenoids, and gibberellins. In addition, these transgenic plants had reduced levels of sesquiterpene emission, suggesting that the export of isoprenoid intermediates from the plastids into the cytosol was decreased. These results provide genetic evidence that GPPS.SSU modifies the chain length specificity of phylogenetically distant GGPPS and can modulate IPP flux distribution between GPP and GGPP synthesis in planta.

Orlova, Irina; Nagegowda, Dinesh A.; Kish, Christine M.; Gutensohn, Michael; Maeda, Hiroshi; Varbanova, Marina; Fridman, Eyal; Yamaguchi, Shinjiro; Hanada, Atsushi; Kamiya, Yuji; Krichevsky, Alexander; Citovsky, Vitaly; Pichersky, Eran; Dudareva, Natalia

2009-01-01

84

Doenças cerebrovasculares em pacientes entre 15 e 40 anos: achados neuropatológicos em 47 casos  

Microsoft Academic Search

RESUMO - As doenças cerebrovasculares em pacientes entre 15 e 40 anos são pouco estudadas na literatura latino americana, principalmente no que tange aos achados neuropatológicos. Analisamos 47 encéfalos provenientes de necrópsias completas realizadas no período de 1987 a 1997 selecionados com base na faixa etária e alteração neuropatológica básica envolvendo fenômenos vasculares. Destes 47 casos analisados, 26 eram (55,3%)

Everton M. Maggio; Mário R. Montemór-Netto; Emerson L. Gasparetto; Jorge S. Reis-Filho; Fábio A. Tironi; Luiz F. Bleggi Torres

2001-01-01

85

BIOHAZARDS AMONG NURSING WORKERS RIESGO BIOLÓGICO ENTRE LOS TRABAJADORES DE ENFERMERÍA  

Microsoft Academic Search

RESUMO: RESUMO: RESUMO: RESUMO: RESUMO: Estudo de revisão bibliográfica que analisou as publicações em periódicos de enfermagem de 1998 a 2005, com o objetivo de caracterizar o perfil das publicações acerca do risco biológico entre trabalhadores de enfermagem. Identificou-se 59 publicações que priorizaram três focos: epidemiologia dos acidentes com material biológico, identificação do risco biológico e medidas preventivas. Predominaram estudos

Almeida ANG; Tipple AFV; Souza ACS

2009-01-01

86

Transferencias entre gobiernos y representación política: elementos empíricos de juicio de Argentina, Brasil y México  

Microsoft Academic Search

(Disponible en idioma inglés únicamente) En los países en desarrollo, las transferencias entre gobiernos desde el nivel central son una fuente importante de ingresos para la mayoría de los gobiernos subnacionales. Y es probable que su importancia aumente aún más, si se toman en cuenta las iniciativas de descentralización en América Latina y otras regiones. En este trabajo se investiga

Moritz Kraemer

1997-01-01

87

Entre 1979 et 1986, la France a perdu des parts de marché industriel  

Microsoft Academic Search

[spa] Entre 1979 y 1986 Francia perdió partes de mercado industrial. Las exportaciones francesas experimentan un cierto retraso con relación a la evolución de la demanda internacional - Francia pierde partes del mercado internacional desde 1979. Las exportaciones francesas siguen estando orientadas hacia los mismos socios que durante los años setenta mientras que los productos vendidos no corresponden totalmente a

Norbert Holcblat; Jean-Luc Tavernier

1989-01-01

88

Competencia entre estímulos condicionales propioceptivos y exteroceptivos en una tarea de discriminación condicional  

Microsoft Academic Search

Se realizó un experimento con sujetos humanos de edades comprendidas entre los 7 y los 53 años en el que se utilizó un procedimiento de discriminación condicional con muestras compuestas formadas por estímulos exteroceptivos (figuras geométricas coloreadas) y propioceptivos (diferentes formas de señalar tales figuras). De esta forma, los sujetos fueron entrenados a emitir una conducta diferencial ante cada muestra

María Teresa Rodríguez García; Andrés García García; María Teresa; Gutiérrez Domínguez; Vicente Pérez Fernández; Cristóbal Bohórquez Zayas

2009-01-01

89

Stress, anxiété et dépression au travail. Existe-t-il des différences entre entreprises ?  

Microsoft Academic Search

En dépit du coût social très élevé du stress au travail, les déterminants des risques psycho-sociaux des salariés demeurent encore largement méconnus en France. Les études portant sur le stress professionnel sont généralement des études de cas, réalisées entreprise par entreprise, ce qui ne permet pas d'appréhender d'éventuels écarts entre les firmes. Le présent travail étudie les déterminants du stress,

Nicolas Gérard Vaillant; François-Charles Wolff

2010-01-01

90

Transfert radiatif entre une petite particule et un diélectrique: application au chauffage local  

NASA Astrophysics Data System (ADS)

nous montrons dans cette étude que le transfert radiatif entre une particule de taille nanométrique et un diélectrique petit être très important lorsque les distances mises en jeu sont petites devant la longueur d'onde caractéristique du rayonnement thermique. Ce transfert peut devenir dominant lorsque les matériaux utilisés sont polaires. Nous discuterons de la possibilité d'appliquer ces résultats au chauffage local dans les nano-structures.

Mulet, J.-P.; Joulain, K.; Carminati, R.; Greffet, J. J.

2002-06-01

91

La concurrence imparfaite entre les intermédiaires financiers est-elle toujours néfaste à la croissance économique ?  

Microsoft Academic Search

Les performances économiques de l'Allemagne et du Japon laissent supposer qu'une faible concurrence entre les intermédiaires financiers n'est pas nécessairement un obstacle à la croissance. Cet article présente un modèle de croissance endogène ne comportant un secteur d'intermédiation financière en concurrence imparfaite. Une forte concentration du secteur bancaire implique un marge d'intermédiation financière importante. Elle exerce un effet négatif sur

Jean-Bernard Chatelain; Bruno Amable

1996-01-01

92

Relation entre formulation et quelques propriétés mécaniques des bétons à hautes performances  

Microsoft Academic Search

Résumé  On s'intéresse dans cette publication aux relations entre composition et propriétés mécaniques (résistance en compression,\\u000a module élastique, retrait endogène) des bétons à hautes performances (BHP) dans la gamme 50–100 MPa. Les modèles proposés\\u000a pour chacune de ces propriétés s'appuient sur une analyse du béton durci en tant que matériau composite, permettant de passer\\u000a des propriétés du béton à celles de

F. de Larrard; R. Le Roy

1992-01-01

93

Les variations des revenus individuels entre périodes de chômage et d'emploi  

Microsoft Academic Search

[fre] Les personnes qui ont connu à la fois le chômage et l’emploi entre 1993 et 1995 ont eu un revenu individuel lors des mois de chômage inférieur de moitié environ à leur revenu lors des mois d’emploi. Cette estimation, tirée des trois premières vagues du Panel européen (1994-1996), retient un concept de revenu individuel assez large, incluant les revenus

Pascale Breuil-Genier

2001-01-01

94

Colonization process of olive tissues by Verticillium dahliae and its in planta interaction with the biocontrol root endophyte Pseudomonas fluorescens PICF7  

PubMed Central

Summary The colonization process of Olea europaea by the defoliating pathotype of Verticillium dahliae, and the in planta interaction with the endophytic, biocontrol strain Pseudomonas fluorescens PICF7 were determined. Differential fluorescent protein tagging was used for the simultaneous visualization of P. fluorescens PICF7 and V. dahliae in olive tissues. Olive plants were bacterized with PICF7 and then transferred to V. dahliae?infested soil. Monitoring olive colonization events by V. dahliae and its interaction with PICF7 was conducted using a non?gnotobiotic system, confocal laser scanner microscopy and tissue vibratoming sections. A yellow fluorescently tagged V. dahliae derivative (VDAT?36I) was obtained by Agrobacterium tumefaciens?mediated transformation. Isolate VDAT?36I quickly colonized olive root surface, successfully invaded root cortex and vascular tissues via macro? and micro?breakages, and progressed to the aerial parts of the plant through xylem vessel cells. Strain PICF7 used root hairs as preferred penetration site, and once established on/in root tissues, hindered pathogen colonization. For the first time using this approach, the entire colonization process of a woody plant by V. dahliae is reported. Early and localized root surface and root endophytic colonization by P. fluorescens PICF7 is needed to impair full progress of verticillium wilt epidemics in olive.

Prieto, Pilar; Navarro-Raya, Carmen; Valverde-Corredor, Antonio; Amyotte, Stefan G.; Dobinson, Katherine F.; Mercado-Blanco, Jesus

2009-01-01

95

Activation of an Arabidopsis resistance protein is specified by the in planta association of its leucine-rich repeat domain with the cognate oomycete effector.  

PubMed

Activation of plant immunity relies on recognition of pathogen effectors by several classes of plant resistance proteins. To discover the underlying molecular mechanisms of effector recognition by the Arabidopsis thaliana RECOGNITION OF PERONOSPORA PARASITICA1 (RPP1) resistance protein, we adopted an Agrobacterium tumefaciens-mediated transient protein expression system in tobacco (Nicotiana tabacum), which allowed us to perform coimmunoprecipitation experiments and mutational analyses. Herein, we demonstrate that RPP1 associates with its cognate effector ARABIDOPSIS THALIANA RECOGNIZED1 (ATR1) in a recognition-specific manner and that this association is a prerequisite step in the induction of the hypersensitive cell death response of host tissue. The leucine-rich repeat (LRR) domain of RPP1 mediates the interaction with ATR1, while the Toll/Interleukin1 Receptor (TIR) domain facilitates the induction of the hypersensitive cell death response. Additionally, we demonstrate that mutations in the TIR and nucleotide binding site domains, which exhibit loss of function for the induction of the hypersensitive response, are still able to associate with the effector in planta. Thus, our data suggest molecular epistasis between signaling activity of the TIR domain and the recognition function of the LRR and allow us to propose a model for ATR1 recognition by RPP1. PMID:20601497

Krasileva, Ksenia V; Dahlbeck, Douglas; Staskawicz, Brian J

2010-07-01

96

In planta expression screens of Phytophthora infestans RXLR effectors reveal diverse phenotypes, including activation of the Solanum bulbocastanum disease resistance protein Rpi-blb2.  

PubMed

The Irish potato famine pathogen Phytophthora infestans is predicted to secrete hundreds of effector proteins. To address the challenge of assigning biological functions to computationally predicted effector genes, we combined allele mining with high-throughput in planta expression. We developed a library of 62 infection-ready P. infestans RXLR effector clones, obtained using primer pairs corresponding to 32 genes and assigned activities to several of these genes. This approach revealed that 16 of the 62 examined effectors cause phenotypes when expressed inside plant cells. Besides the well-studied AVR3a effector, two additional effectors, PexRD8 and PexRD36(45-1), suppressed the hypersensitive cell death triggered by the elicitin INF1, another secreted protein of P. infestans. One effector, PexRD2, promoted cell death in Nicotiana benthamiana and other solanaceous plants. Finally, two families of effectors induced hypersensitive cell death specifically in the presence of the Solanum bulbocastanum late blight resistance genes Rpi-blb1 and Rpi-blb2, thereby exhibiting the activities expected for Avrblb1 and Avrblb2. The AVRblb2 family was then studied in more detail and found to be highly variable and under diversifying selection in P. infestans. Structure-function experiments indicated that a 34-amino acid region in the C-terminal half of AVRblb2 is sufficient for triggering Rpi-blb2 hypersensitivity and that a single positively selected AVRblb2 residue is critical for recognition by Rpi-blb2. PMID:19794118

Oh, Sang-Keun; Young, Carolyn; Lee, Minkyoung; Oliva, Ricardo; Bozkurt, Tolga O; Cano, Liliana M; Win, Joe; Bos, Jorunn I B; Liu, Hsin-Yin; van Damme, Mireille; Morgan, William; Choi, Doil; Van der Vossen, Edwin A G; Vleeshouwers, Vivianne G A A; Kamoun, Sophien

2009-09-01

97

Temporal and spatial regulation of the symbiotic genes of Rhizobium meliloti in planta revealed by transposon Tn5-gusA.  

PubMed

Tn5-gusA promoter/probe transposons have been constructed that fuse the Escherichia coli gusA reporter gene transcriptionally or translationally with a target promoter. These have been used to monitor expression of Rhizobium meliloti symbiotic genes within alfalfa nodules. Fusions in all 11 nod genes studied show the same pattern of expression: first on the root surface, then throughout the developing nodule, then mainly in the nodule meristem, falling off progressively through the central region, and then disappearing. In contrast, fusions in all five nif genes studied, all four fix genes, and syrM show a second, different pattern: expression beginning later, first throughout the nodule except for the meristem, strongest just behind the meristem, and falling off progressively through the central region. Novel features revealed by these studies include nod expression in the meristem, regulated in planta expression of control genes nodD1 and nodD3, disappearance of nod expression late in organogenesis, and properties of syrM. PMID:2159937

Sharma, S B; Signer, E R

1990-03-01

98

Mutations in the capsid protein of Brome mosaic virus affecting encapsidation eliminate vesicle induction in planta: implications for virus cell-to-cell spread.  

PubMed

Positive-strand RNA viruses are known to rearrange the endomembrane network to make it more conducive for replication, maturation, or egress. Our previous transmission electron microscopic (TEM) analysis showed that ectopic expression of wild-type (wt) capsid protein (CP) of Brome mosaic virus (BMV) has an intrinsic property of modifying the endoplasmic reticulum (ER) to induce vesicles similar to those present in wt BMV infection. In this study, we evaluated the functional significance of CP-mediated vesicle induction to the BMV infection cycle in planta. Consequently, the cytopathologic changes induced by wt CP or its mutants defective in virion assembly due to mutations engineered in either N- or C-proximal domains were comparatively analyzed by TEM in two susceptible (Nicotiana benthamiana and Chenopodium quinoa) and one nonhost (N. clevelandii) plant species. The results showed that in susceptible hosts, CP-mediated ER-derived vesicle induction is contingent on the expression of encapsidation-competent CP. In contrast, unlike in N. benthamiana and C. quinoa, transient expression of wt CP in nonhost N. clevelandii plants eliminated vesicle induction. Additionally, comparative source-to-sink analysis of virus spread in leaves of N. benthamiana and N. clevelandii coexpressing wt BMV and Cucumber mosaic virus (CMV) showed that despite trans-encapsidation, CMV failed to complement the defective cell-to-cell movement of BMV. The significance and relation of CP-mediated vesicle induction to virus cell-to-cell movement are discussed. PMID:23741003

Bamunusinghe, Devinka; Chaturvedi, Sonali; Seo, Jang-Kyun; Rao, A L N

2013-08-01

99

Genetic modification of potato against microbial diseases: in vitro and in planta activity of a dermaseptin B1 derivative, MsrA2.  

PubMed

Dermaseptin B1 is a potent cationic antimicrobial peptide found in skin secretions of the arboreal frog Phyllomedusa bicolor. A synthetic derivative of dermaseptin B1, MsrA2 (N-Met-dermaseptin B1), elicited strong antimicrobial activities against various phytopathogenic fungi and bacteria in vitro. To assess its potential for plant protection, MsrA2 was expressed at low levels (1-5 microg/g of fresh tissue) in the transgenic potato (Solanum tuberosum L.) cv. Desiree. Stringent challenges of these transgenic potato plants with a variety of highly virulent fungal phytopathogens--Alternaria, Cercospora, Fusarium, Phytophthora, Pythium, Rhizoctonia and Verticillium species--and with the bacterial pathogen Erwinia carotovora demonstrated that the plants had an unusually broad-spectrum and powerful resistance to infection. MsrA2 profoundly protected both plants and tubers from diseases such as late blight, dry rot and pink rot and markedly extended the storage life of tubers. Due to these properties in planta, MsrA2 is proposed as an ideal antimicrobial peptide candidate to significantly increase resistance to phytopathogens and improve quality in a variety of crops worldwide with the potential to obviate fungicides and facilitate storage under difficult conditions. PMID:15947906

Osusky, Milan; Osuska, Lubica; Kay, William; Misra, Santosh

2005-08-01

100

In Planta Stage-Specific Fungal Gene Profiling Elucidates the Molecular Strategies of Fusarium graminearum Growing inside Wheat Coleoptiles[W][OA  

PubMed Central

The ascomycete Fusarium graminearum is a destructive fungal pathogen of wheat (Triticum aestivum). To better understand how this pathogen proliferates within the host plant, we tracked pathogen growth inside wheat coleoptiles and then examined pathogen gene expression inside wheat coleoptiles at 16, 40, and 64 h after inoculation (HAI) using laser capture microdissection and microarray analysis. We identified 344 genes that were preferentially expressed during invasive growth in planta. Gene expression profiles for 134 putative plant cell wall–degrading enzyme genes suggest that there was limited cell wall degradation at 16 HAI and extensive degradation at 64 HAI. Expression profiles for genes encoding reactive oxygen species (ROS)–related enzymes suggest that F. graminearum primarily scavenges extracellular ROS before a later burst of extracellular ROS is produced by F. graminearum enzymes. Expression patterns of genes involved in primary metabolic pathways suggest that F. graminearum relies on the glyoxylate cycle at an early stage of plant infection. A secondary metabolite biosynthesis gene cluster was specifically induced at 64 HAI and was required for virulence. Our results indicate that F. graminearum initiates infection of coleoptiles using covert penetration strategies and switches to overt cellular destruction of tissues at an advanced stage of infection.

Zhang, Xiao-Wei; Jia, Lei-Jie; Zhang, Yan; Jiang, Gang; Li, Xuan; Zhang, Dong; Tang, Wei-Hua

2012-01-01

101

In Planta Biocontrol of Pectobacterium atrosepticum by Rhodococcus erythropolis Involves Silencing of Pathogen Communication by the Rhodococcal Gamma-Lactone Catabolic Pathway  

PubMed Central

The virulence of numerous Gram-negative bacteria is under the control of a quorum sensing process based on synthesis and perception of N-acyl homoserine lactones. Rhodococcus erythropolis, a Gram-positive bacterium, has recently been proposed as a biocontrol agent for plant protection against soft-rot bacteria, including Pectobacterium. Here, we show that the ?-lactone catabolic pathway of R. erythropolis disrupts Pectobacterium communication and prevents plant soft-rot. We report the first characterization and demonstration of N-acyl homoserine lactone quenching in planta. In particular, we describe the transcription of the R. erythropolis lactonase gene, encoding the key enzyme of this pathway, and the subsequent lactone breakdown. The role of this catabolic pathway in biocontrol activity was confirmed by deletion of the lactonase gene from R. erythropolis and also its heterologous expression in Escherichia coli. The ?-lactone catabolic pathway is induced by pathogen communication rather than by pathogen invasion. This is thus a novel and unusual biocontrol pathway, differing from those previously described as protecting plants from phytopathogens. These findings also suggest the existence of an additional pathway contributing to plant protection.

Barbey, Corinne; Crepin, Alexandre; Bergeau, Dorian; Ouchiha, Asma; Mijouin, Lily; Taupin, Laure; Orange, Nicole; Feuilloley, Marc; Dufour, Alain; Burini, Jean-Francois; Latour, Xavier

2013-01-01

102

A Functional Histidine-Tagged Replication Initiator Protein: Implications for the Study of Single-Stranded DNA Virus Replication In Planta  

PubMed Central

Replication initiation of nanoviruses, plant viruses with a multipartite circular single-stranded DNA genome, is triggered by the master Rep (M-Rep) protein. To enable the study of interactions between M-Rep and viral or host factors involved in replication, we designed oligohistidine-tagged variants of the nanovirus Faba bean necrotic yellows virus (FBNYV) M-Rep protein that allow affinity purification of enzymatically active M-Rep from plant tissue. The tagged M-Rep protein was able to initiate replication of its cognate and other FBNYV DNAs in Nicotiana benthamiana leaf disks and plants. The replicon encoding the tagged M-Rep protein multiplied and moved systemically in FBNYV-infected Vicia faba plants and was transmitted by the aphid vector of the virus. Using the tagged M-Rep protein, we demonstrated the in planta interaction between wild-type M-Rep and its tagged counterpart. Such a tagged and fully functional replication initiator protein will have bearings on the isolation of protein complexes from plants.

Vega-Arreguin, Julio C.; Timchenko, Tatiana; Gronenborn, Bruno; Ramirez, Bertha Cecilia

2005-01-01

103

Etude des relations entre photosynthese respiration, transpiration et nutrition minerale chez le ble  

NASA Astrophysics Data System (ADS)

La croissance du Blé Triticum aestivum a été étudiée en environnement contrôlé et fermé pendant une période de 70 jours. Les échanges gazeux (Photosynthèse, Respiration) hydriques (Transpiration) et la consommation en éléments minéraux (Azote, Phosphore, Potassium) ont été mesurés en continu. On présentera les relations dynamiques observées entre les différentes fonctions physiologiques, d'une part sous l'influence de la croissance et d'autre part en réponse à des modifications de l'environnement. L'influence de la teneur en CO2 pendant la croissance (teneur normale ou doublée) sera mise en évidence.

André, M.; Ducloux, H.; Richaud, C.; Massimino, D.; Daguenet, A.; Massimino, J.; Gerbaud, A.

104

Endogenous silencing of Puccinia triticina pathogenicity genes through in planta-expressed sequences leads to the suppression of rust diseases on wheat.  

PubMed

Rust fungi are destructive plant pathogens. The draft genomes of several wheat-infecting species have been released and potential pathogenicity genes identified through comparative analyses to fungal pathogens that are amenable to genetic manipulation. Functional gene analysis tools are needed to understand the infection process of these obligate parasites and to confirm whether predicted pathogenicity genes could become targets for disease control. We have modified an Agrobacterium tumefaciens-mediated in planta-induced transient gene silencing (PITGS) assay for use in Triticum spp. (wheat), and used this assay to target predicted wheat leaf rust fungus, Puccinia triticina (Pt) pathogenicity genes, a MAP kinase (PtMAPK1), a cyclophilin (PtCYC1) and calcineurin B (PtCNB), to analyze their roles in disease. Agroinfiltration effectively delivered hairpin silencing constructs in wheat, leading to the generation of fungal gene-specific siRNA molecules in infiltrated leaves, and resulting in up to 70% reduction in transcription of the endogenous target genes in superinfected Pt. In vivo silencing caused severe disease suppression, compromising fungal growth and sporulation, as viewed by confocal microscopy and measured by reductions in fungal biomass and emergence of uredinia. Interestingly, using the same gene constructs, suppression of infection by Puccinia graminis and Puccinia striiformis was also achieved. Our results show that A. tumefaciens-mediated PITGS can be used as a reverse-genetics tool to discover gene function in rust fungi. This proof-of-concept study indicates that the targeted fungal transcripts might be important in pathogenesis, and could potentially be used as promising targets for developing RNA interference-based resistance against rust fungi. PMID:23110316

Panwar, Vinay; McCallum, Brent; Bakkeren, Guus

2013-02-01

105

In Planta Assessment of the Role of Thioredoxin h Proteins in the Regulation of S-Locus Receptor Kinase Signaling in Transgenic Arabidopsis1[W][OPEN  

PubMed Central

The self-incompatibility (SI) response of the Brassicaceae is mediated by allele-specific interaction between the stigma-localized S-locus receptor kinase (SRK) and its ligand, the pollen coat-localized S-locus cysteine-rich protein (SCR). Based on work in Brassica spp., the thioredoxin h-like proteins THL1 and THL2, which interact with SRK, have been proposed to function as oxidoreductases that negatively regulate SRK catalytic activity. By preventing the spontaneous activation of SRK in the absence of SCR ligand, these thioredoxins are thought to be essential for the success of cross pollinations in self-incompatible plants. However, the in planta role of thioredoxins in the regulation of SI signaling has not been conclusively demonstrated. Here, we addressed this issue using Arabidopsis thaliana plants transformed with the SRKb-SCRb gene pair isolated from self-incompatible Arabidopsis lyrata. These plants express an intense SI response, allowing us to exploit the extensive tools and resources available in A. thaliana for analysis of SI signaling. To test the hypothesis that SRK is redox regulated by thioredoxin h, we expressed a mutant form of SRKb lacking a transmembrane-localized cysteine residue thought to be essential for the SRK-thioredoxin h interaction. We also analyzed transfer DNA insertion mutants in the A. thaliana orthologs of THL1 and THL2. In neither case did we observe an effect on the pollination responses of SRKb-expressing stigmas toward incompatible or compatible pollen. Our results are consistent with the conclusion that, contrary to their proposed role, thioredoxin h proteins are not required to prevent the spontaneous activation of SRK in the A. thaliana stigma.

Yamamoto, Masaya; Nasrallah, June B.

2013-01-01

106

Boosting In Planta Production of Antigens Derived from the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Subsequent Evaluation of Their Immunogenicity  

PubMed Central

Porcine reproductive and respiratory syndrome (PRRS) is a disease of swine, caused by an arterivirus, the PRRS virus (PRRSV). This virus infects pigs worldwide and causes huge economic losses. Due to genetic drift, current vaccines are losing their power. Adaptable vaccines could provide a solution to this problem. This study aims at producing in planta a set of antigens derived from the PRRSV glycoproteins (GPs) to be included in a subunit vaccine. We selected the GP3, GP4 and GP5 and optimized these for production in an Arabidopsis seed platform by removing transmembrane domains (Tm) and/or adding stabilizing protein domains, such as the green fluorescent protein (GFP) and immunoglobulin (IgG) ‘Fragment crystallizable’ (Fc) chains. Accumulation of the GPs with and without Tm was low, reaching no more than 0.10% of total soluble protein (TSP) in homozygous seed. However, addition of stabilizing domains boosted accumulation up to a maximum of 2.74% of TSP when GFP was used, and albeit less effectively, also the Fc chains of the porcine IgG3 and murine IgG2a increased antigen accumulation, to 0.96% and 1.81% of TSP respectively, while the murine IgG3 Fc chain did not. Antigens with Tm were less susceptible to these manipulations to increase yield. All antigens were produced in the endoplasmic reticulum and accordingly, they carried high-mannose N-glycans. The immunogenicity of several of those antigens was assessed and we show that vaccination with purified antigens did elicit the production of antibodies with virus neutralizing activity in mice but not in pigs.

Piron, Robin; De Koker, Stefaan; De Paepe, Annelies; Goossens, Julie; Grooten, Johan; Nauwynck, Hans; Depicker, Ann

2014-01-01

107

Post-abscission, pre-dispersal seeds of Digitalis purpurea remain in a developmental state that is not terminated by desiccation ex planta  

PubMed Central

Background and Aims Seed quality may be compromised if seeds are harvested before natural dispersal (shedding). It has been shown previously that slow or delayed drying can increase potential quality compared with immediate rapid drying. This study set out to investigate whether or not there is a critical moisture content, below which drying terminates maturation events for seeds harvested after mass maturity but before dispersal. Methods Seeds of foxglove (Digitalis purpurea) in the post-abscission pre-dispersal phase were held at between 15 and 95 % RH for 4 or 8 d, with or without re-hydration to 95 % RH for a further 4 d, before drying to equilibrium at 15 % RH. In addition, dry seeds were primed for 48 h at ?1 MPa. Subsequent seed longevity was assessed at 60 % RH and 45 °C. Key Results Rate of germination and longevity were improved by holding seeds at a wide range of humidities after harvest. Longevity was further improved by re-hydration at 95 % RH. Priming improved the longevity of the seeds dried immediately after harvest, but not of those first held at 95 % RH for 8 d prior to drying. Conclusions Maturation continued ex planta in these post-abscission, pre-dispersal seeds of D. purpurea dried at 15–80 % RH at a rate correlated positively with RH (cf. ageing of mature seeds). Subsequent re-hydration at 95 % RH enabled a further improvement in quality. Priming seeds initially stored air-dry for 3 months also allowed maturation events to resume. However, once individual seeds within the population had reached maximum longevity, priming had a negative impact on their subsequent survival.

Butler, L. H.; Hay, F. R.; Ellis, R. H.; Smith, R. D.

2009-01-01

108

XerR, a negative regulator of XccR in Xanthomonas campestris pv. campestris, relieves its repressor function in planta  

PubMed Central

We previously reported that XccR, a LuxR-type regulator of Xanthomonas campestris pv. campestris (Xcc), activates the downstream proline iminopeptidase virulence gene (pip) in response to certain host plant factor(s). In this report, we further show that the expression of the xccR gene was repressed in the culture medium by an NtrC-type response regulator, which we named XerR (XccR expression-related, repressor), and that this repression was relieved when the bacteria were grown in planta. Such a regulatory mechanism is reinforced by the observations that XerR directly bound to the xccR promoter in vitro, and that mutations at the phosphorylation-related residues of XerR resulted in the loss of its repressor function. Furthermore, the expression level of xccR increased even in XerR-overexpressing Xcc cells when they were vacuum infiltrated into cabbage plants. We also preliminarily characterized the host factor(s) involved in the above mentioned interactions between Xcc and the host plant, showing that a plant material(s) with molecular weight(s) less than 1 kDa abolished the binding of XerR to the xccR promoter, while the same material enhanced the binding of XccR to the luxXc box in the pip promoter. Taken together, our results implicate XerR in a new layer of the regulatory mechanism controlling the expression of the virulence-related xccR/pip locus and provide clues to the identification of plant signal molecules that interact with XerR and XccR to enhance the virulence of Xcc.

Wang, Li; Zhang, Lili; Geng, Yunfeng; Xi, Wei; Fang, Rongxiang; Jia, Yantao

2011-01-01

109

Differential subcellular targeting of recombinant human ??-proteinase inhibitor influences yield, biological activity and in planta stability of the protein in transgenic tomato plants.  

PubMed

The response of protein accumulation site on yield, biological activity and in planta stability of therapeutic recombinant human proteinase inhibitor (??-PI) was analyzed via targeting to different subcellular locations, like endoplasmic reticulum (ER), apoplast, vacuole and cytosol in leaves of transgenic tomato plants. In situ localization of the recombinant ??-PI protein in transgenic plant cells was monitored by immunohistochemical staining. Maximum accumulation of recombinant ??-PI in T? and T? transgenic tomato plants was achieved from 1.5 to 3.2% of total soluble protein (TSP) by retention in ER lumen, followed by vacuole and apoplast, whereas cytosolic targeting resulted into degradation of the protein. The plant-derived recombinant ??-PI showed biological activity for elastase inhibition, as monitored by residual porcine pancreatic elastase (PPE) activity assay and band-shift assay. Recombinant ??-PI was purified from transgenic tomato plants with high yield, homogeneity and biological activity. Purified protein appeared as a single band of ?48-50 kDa on SDS-PAGE with pI value ranging between 5.1 and 5.3. Results of mass spectrometry and optical spectroscopy of purified recombinant ??-PI revealed the structural integrity of the recombinant protein comparable to native serum ??-PI. Enzymatic deglycosylation and lectin-binding assays with the purified recombinant ??-PI showed compartment-specific N-glycosylation of the protein targeted to ER, apoplast and vacuole. Conformational studies based on urea-induced denaturation and circular dichroism (CD) spectroscopy revealed relatively lower stability of the recombinant ??-PI protein, compared to its serum counterpart. Pharmacokinetic evaluation of plant derived recombinant and human plasma-purified ??-PI in rat, by intravenous route, revealed significantly faster plasma clearance and lower area under curve (AUC) of recombinant protein. Our data suggested significance of protein sorting sequences and feasibility to use transgenic plants for the production of stable, glycosylated and biologically active recombinant ??-PI for further therapeutic applications. PMID:23017899

Jha, Shweta; Agarwal, Saurabh; Sanyal, Indraneel; Jain, G K; Amla, D V

2012-11-01

110

Determinação de elementos próprios dos asteróides troianos: comparação entre as teorias semi-analítica e sintética  

NASA Astrophysics Data System (ADS)

Além do cálculo semi-analítico de elementos próprios dos asteróides Troianos (Beaugé & Roig 2001, Icarus 153, 391), recentemente foi apresentado um novo conjunto destes elementos próprios determinado através de uma teoria sintética (Knenezevic & Milani 2003, comunicação pessoal). As bases de dados contendo estas determinações estão disponiveis na pagina web do Asteroid Dynamical Site (http://hamilton.dm.unipi.it/cgi-bin/astdys/astibo). Nesta comunicação apresentamos os primeiros resultados de um estudo comparativo entre ambos conjuntos de elementos próprios, analisando suas vantagens e desvantagens, assim como os limites de precisão de cada conjunto. Mostramos que os elementos próprios sintéticos são mais precisos que os smi-analíticos para grandes amplitudes de libração do ângulo s = l-lJup, embora acontece o contrario para os corpos cuja amplitude de libração é muito pequena. Finalmente discutimos a influencia destes erros na determinação de familias de asteroides e da estrutura resonante em torno dos pontos Lagrangeanos L4 e L5.

Roig, F.; Beaugé, C.

2003-08-01

111

State of Conservation of the Native Forests in Entre Ríos (Argentina) and Changes in Land Use  

NASA Astrophysics Data System (ADS)

The native forest area of Entre Ríos province (Argentina) is associated with a constant change in land use, with an increase in recent years in agricultural use, especially for soybean crop. In addition, since its inadequate management has triggered degradation processes of the natural forest structure, the implementation of strategies for the restoration and conservation of native forests has become a priority. The aim of this study was to diagnose the conservation state of the native forest in the basin of the Estacas Stream (Entre Ríos, Argentina) after the change in land use, to help design guidelines for the restoration and sustainable management of these ecosystems. The field study was conducted in October 2010, in a representative area of the native forest of 73,000 ha. Using Landsat 5-TM images (INPE), environments were separated by manual vectorization, identifying and classifying native forests and other lands (agricultural, urban). Using a field exploratory survey (58 geo-referenced sampling points), we developed patterns corresponding to the different types of forests, contrasting this information with the digital data of the images. The native forests were classified according to type (high/low forest, open/closed forest, savanna), successional stage (climax, successional or regeneration forest) and degree of disturbance (weed growth, erosion, fire), and their frequency determined. Each classification was assessed by a contingency matrix, and global reliability index and the Kappa index. The information obtained generated a classification map of native forests in the basin scale. We found that the native forest covered an area of 42,726.91 ha, accounting for 58.52% of the total basin area, and that the rest corresponded to other land uses. The most frequent native forests (59.09%) were climax forest, but accounted for only 8.2% of the basin area. Within this group, the most important were the low and open forest, with Prosopis affinis and Prosopis nigra as the dominant tree species. Although the successional forests were not the most frequent, they occupied the greater area of the basin (30.8%), being low and open forest the dominant type. The regeneration forest dominated by Acacia caven, represents 18.71% of the basin area. Weed shrub species growth was the most frequent disturbance. We determined a severe weed shrub growth in 41% of the sampling points, with Baccharis punctulata and Eupatorium buniifolium as the dominant species. According to state of conservation of native forest, 7,797.03 ha have a high conservation value, while 21,272.17 ha and 13,657.71 ha have a medium and low conservation value, respectively.

Sabattini, R. A.; Sione, S. M.; Ledesma, S. G.; Sabattini, J. A.; Wilson, M. G.

2012-04-01

112

On acoplamento mecânico entre a antena e o transdutor no detector de ondas gravitacionais Mario Schenberg  

NASA Astrophysics Data System (ADS)

O detector de ondas gravitacionais MARIO SCHENBERG consistirá de uma massa esférica de cobre-alumínio de 1150kg resfriada a 4K, sobre a qual serão instalados 6 transdutores de nióbio. Com estes trandutores pretende-se converter um possível sinal de onda gravitacional detectado em sinal elétrico, para tanto é necessário que o acoplamento mecânico entre os transdutores e a massa ressonante seja o maior possível. Isto significa que o transdutor deve ser ressonante na mesma freqüência que a antena (aproximadamente 3200Hz). Neste trabalho foi desenvolvida uma geometria para a estrutura mecânica do trandutor. Isto foi feito criando-se modelos em elementos finitos usando-se o "software" MSC/Nastran. Estes modelos criados foram analisados estaticamente (cálculo de tensões) e dinamicamente (cálculo das freqüências de ressonâncias e seus respectivos modos normais) de maneira a se obter o primeiro modo normal do transdutor em 3200Hz. A partir destes cálculos escolheu-se a melhor geometria para o transdutor. Os próximos passos do trabalho serão: usinar este transdutor em uma barra de nióbio e testá-lo à temperatura ambiente e à baixa temperatura. Após isto, pretende-se testá-lo na própria antena resfriada.

Melo, J. L.; Aguiar, O. D.; Velloso, W. F., Jr.; Lucena, A. U.

2003-08-01

113

Natural co-occurrence of fungi and mycotoxins in poultry feeds from Entre Ríos, Argentina.  

PubMed

A total of 120 pelleted poultry feed samples from Entre Ríos Province, Argentina, were evaluated. The aims were to investigate (1) the presence of relevant toxigenic fungi, as well as to determine the ability to produce aflatoxins (AFs) by Aspergillus section Flavi isolated strains; and (2) the natural co-occurrence of AFs, fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Total fungal counts were below the established value (1 × 10(4) CFU g(-1)). Aspergillus flavus and A. parasiticus were the only aflatoxigenic species isolated. Co-occurrence of fumonisin B1 (FB1), HT-2 and T-2 toxin was detected in 100% of the feeds, with mean levels from 4502 to 5813; 6.7 to 21.6 and 19.6 to 30.3 µg kg(-1), respectively. A large number of starter samples were co-contaminated with aflatoxin B1 (AFB1), FB1, HT-2 and T-2 toxins. Gliotoxin and DAS were not found in this survey. PMID:24779900

Monge, M P; Dalcero, A M; Magnoli, C E; Chiacchiera, S M

2013-09-01

114

Interseções entre cultura midiática, cibercultura e gamecultura: o Ragnarök como processo sociocomunicacional e mediador da conscientização ambiental  

Microsoft Academic Search

Os games on-line são estudados na atualidade como mídias interativas complexas. Neste artigo compreendemos os games on-line como resultados das relações entre a cultura midiática, cibercultura e gamecultura. Propomos demonstrar que sua finalidade está na socialização dos jogadores, nos \\

Igor Ramady; Lira de SOUSA; Henrique Paiva de MAGALHÃES

115

El conflicto entre la demanda de flexibilidad laboral y la resistencia a la reforma del mercado de trabajo en España  

Microsoft Academic Search

La resistencia a las reformas laborales puede explicarse como un conflicto de intereses entre colectivos de individuos con distintas preferencias sobre la flexibilidad laboral. En este artículo presentamos evidencia empírica sobre cómo varían estas preferencias en función de las características socio-económicas de los ciudadanos en España. Documentamos que, a diferencia de lo que ocurre en los países de nuestro entorno,

Juan José Dolado; Florentino Felgueroso; Marcel Jansen

2010-01-01

116

Acuerdos entre el gobierno central y los departamentos: una propuesta para aumentar la eficiencia del gasto público  

Microsoft Academic Search

El objetivo de este trabajo es proponer un instrumento para el seguimiento de la eficiencia del gasto público. El instrumento muestra que el gobierno central se puede apoyar en las administraciones departamentales con el fin de medir los productos del gasto. La idea central de la propuesta es que los objetivos de productividad acordados entre el nivel nacional y el

Isaac de León-Beltrán; Diego Jaramillo

2006-01-01

117

Una Metodología para Ajustar y Compensar las Diferencias de Riesgo entre el Sistema Público y Privado de Salud en Chile  

Microsoft Academic Search

En el marco conceptual de seguros de salud y ajuste de riesgo y a la luz de la experiencia internacional en Fondos de Compensación de Riesgos, este documento explora el problema del «descreme» que afecta al sistema de seguros Chileno. Se presenta una metodología para estimar diferencias de riesgo entre el sector público y privado de salud en Chile y

Verónica Vargas; Camilo Cid; Mauricio Matus; Iris Delgado; José Miguel Sánchez; Beatriz Heyermann; José Angulo

118

Occurrence of alternariol and alternariol monomethyl ether in beverages from the Entre Rios Province market, Argentina.  

PubMed

One hundred and eighty five samples of red, white and rosé wines and different juices purchased in Entre Rios, Argentina, were analyzed for the Alternaria mycotoxins alternariol (AOH) and alternariol methyl ether (AME). White wines were analyzed after removal of alcohol by a nitrogen stream and concentrated. AOH in red wines was cleaned up by solid-phase extraction columns in series (octadecyl and amino propyl modified silica) and AME quantified directly on the sample. The juices were filtered and concentrated, and then all sample extracts were quantified by high performance liquid chromatography with photodiode array detector that allows confirmation through UV spectra. Method validation revealed a good sensitivity with adequate LOD and LOQ for AME and less sensitivity for AOH (i.e. white wine: AME 0.8 and 1.4 ng/mL, AOH 2 and 3.3 ng/mL; red wine: AME 0.1 and 0.2 ng/mL, AOH 4.5 and 7.5 ng/mL; apple juice: AME 1.7 and 2.8 ng/mL, AOH 5 and 9 ng/mL; other juices: AME 2.0 and 3.1 ng/mL, AOH 6 and 10 ng/mL). Recoveries in all cases were greater than 80 %. Four of 53 white wine samples were contaminated with AOH with a maximum level of 18 ng/mL, 6 of 56 samples of red wine had a maximum of 13 ng/mL, and 3 of 68 samples of juices had traces of AOH. AME was less frequently detected than AOH, and the LOD and LOQ for AME are smaller than for AOH. Only three samples of white wine and one of red wine were contaminated, but in only one white wine sample (AME 225 ng/mL) did the toxin level exceed the LOQ. PMID:23334721

Broggi, Leticia; Reynoso, Cora; Resnik, Silvia; Martinez, Fernanda; Drunday, Vanesa; Bernal, Angela Romero

2013-02-01

119

Analyse des interactions energetiques entre un arena et son systeme de refrigeration  

NASA Astrophysics Data System (ADS)

La presente these s'inscrit dans le cadre d'un projet strategique sur les arenas finance par le CRSNG (Conseil de Recherche en Sciences Naturelles et en Genie du Canada) qui a pour but principal le developpement d'un outil numerique capable d'estimer et d'optimiser la consommation d'energie dans les arenas et curlings. Notre travail s'inscrit comme une suite a un travail deja realise par DAOUD et coll. (2006, 2007) qui a developpe un modele 3D (AIM) en regime transitoire de l'arena Camilien Houde a Montreal et qui calcule les flux de chaleur a travers l'enveloppe du batiment ainsi que les distributions de temperatures et d'humidite durant une annee meteorologique typique. En particulier, il calcule les flux de chaleur a travers la couche de glace dus a la convection, la radiation et la condensation. Dans un premier temps nous avons developpe un modele de la structure sous la glace (BIM) qui tient compte de sa geometrie 3D, des differentes couches, de l'effet transitoire, des gains de chaleur du sol en dessous et autour de l'arena etudie ainsi que de la temperature d'entree de la saumure dans la dalle de beton. Par la suite le BIM a ete couple le AIM. Dans la deuxieme etape, nous avons developpe un modele du systeme de refrigeration (REFSYS) en regime quasi-permanent pour l'arena etudie sur la base d'une combinaison de relations thermodynamiques, de correlations de transfert de chaleur et de relations elaborees a partir de donnees disponibles dans le catalogue du manufacturier. Enfin le couplage final entre l'AIM +BIM et le REFSYS a ete effectue sous l'interface du logiciel TRNSYS. Plusieurs etudes parametriques on ete entreprises pour evaluer les effets du climat, de la temperature de la saumure, de l'epaisseur de la glace, etc. sur la consommation energetique de l'arena. Aussi, quelques strategies pour diminuer cette consommation ont ete etudiees. Le considerable potentiel de recuperation de chaleur au niveau des condenseurs qui peut reduire l'energie requise par le systeme de ventilation de l'arena a ete mis en evidence. Mots cles. Arena, Systeme de refrigeration, Consommation d'energie, Efficacite energetique, Conduction au sol, Performance annuelle.

Seghouani, Lotfi

121

La racialisation de la sante publique aux Etats-Unis : entre pouvoir sur la vie et droit de laisser mourir.  

PubMed

RSUM Aux États-Unis, une intensification de l'usage de la race en santé publique a récemment été notée ; une idée qui est pourtant controversée dans les sciences. La race a été vue dans ce contexte comme un objet de discours entre pouvoirs et savoirs, un objet qui se réfère au corps devenu au cours des derniers siècles un site discursif pour représenter la différence. Cet article s'appuie sur une analyse de documents de la santé publique parus aux États-Unis et issus de bureaux fédéraux et d'une importante revue spécialisée dans le domaine sanitaire, qui ont été publiés entre 2001 et 2009. Cette étude a analysé la manière dont la race est représentée, produite comme objet de connaissance et régulée par les pratiques discursives dans ces documents. Les résultats décrivent deux processus enchevêtrés, la racialisation et la sanitarisation, qui concourent à reformuler l'idée de race. Le premier est un ensemble d'opérations qui visent à identifier, à situer et à opposer les sujets et les groupes à partir de labels standardisés. La sanitarisation assure la traduction des groupes racialisés en termes de maladies, de comportements, de vie ou de mort. Ces pratiques aboutissent à la caractérisation et à la formation d'objets racialisés et sanitarisés et à des stéréotypes ; un ensemble d'opérations qui a tendance à naturaliser la différence. La racialisation apparaît également tiraillée entre un pouvoir sur la vie et un droit de laisser mourir. Enfin, cette étude propose aux acteurs de la santé publique de sortir des frontières imposées par le discours racialisant. PMID:24801319

Cloos, Patrick

2012-03-01

122

La Maîtrise Intuitive des Relations entre Masse, Volume et Masse Volumique Chez des Elèves du Premier Cycle  

Microsoft Academic Search

Résumé  Dans le cadre de la théorie de l'integration de l'information, trois expériences sont consacrées à l'application de la méthodologie\\u000a développée par Anderson au problème de la maîtrise chez des élèves français du secondaire, des relations entre les notions\\u000a de masse, volume et masse volumique. Il apparaît que, s'agissant de juger de la masse d'objets divers dont ils connaissent\\u000a la masse

Etienne Mullet; Daniel Vidal

1986-01-01

123

Servicio de Mapas en Internet para la Salud Ambiental en la Region Fronteriza Entre los Estados Unidos y Mexico  

USGS Publications Warehouse

La region fronteriza de los Estados Unidos y Mexico abarca una gran diversidad de ambientes fisicos y habitaciones, entre los cuales estan los humedales, desiertos, pastos, montanas, y bosques. Estos a su vez son unicos en cuanto a su diversidad de recursos acuaticos minerales, y biologicos. La region se interconecta economica, politica, y socialmente debido a su herencia binacional. En 1995, cerca de 11 millones de habitantes vivian en la zona adyacente a la frontera. Un estudio sugiere que esa poblacion podria doblarse antes del ano 2020.

Buckler, Denny; Stefanov, Jim

2004-01-01

124

L’interconnexion entre la sécurité des communautés et les programmes de Démobilisation, Désarmement et Réintégration (DDR) : une étude de terrain au Congo Oriental (RDC)  

Microsoft Academic Search

Ce compte-rendu est le résultat d'une enquête de 11 semaines sur le terrain dans l‘Est de la République démocratique du Congo (RDC) entre septembre et décembre 2009. Le but de ce rapport est d'analyser les relations entre les questions de sécurité au sein des différentes communautés et le contexte des programmes de Désarmement, Démobilisation et Réintégration (DDR) - en nous

R. C. Willems; H. Rouw

2010-01-01

125

Etude de la transition tribologique entre le fretting et le meso-fretting pour des materiaux de contact electrique  

NASA Astrophysics Data System (ADS)

Dans les installations electriques, les contacts sont toujours soumis a des contraintes alternees ou a des micro-deplacements. Il en resulte une corrosion par fretting, phenomene defini comme un type de deterioration de la surface qui se produit lorsque deux materiaux en contact sont soumis a des mouvements microscopiques d'oscillations de tres faible amplitude (0 a 100 mum). Ceci a pour effet de provoquer une degradation de la resistance de contact et une interruption du passage du courant. Ce phenomene a des repercussions considerables sur le plan pratique puisque les micro-deplacements de pieces en contact peuvent etre causes par la dilatation thermique differentielle des metaux, par des vibrations mecaniques, par la relaxation des contraintes ou par l'echauffement des contacts lorsqu'on interrompt et retablit le courant. Nous avons donc dans le cadre de cette these etudie plusieurs aspects du fretting (0--100 mum) et du meso-fretting (100 a 1000 mum) pour differents materiaux de contact electrique. Des travaux experimentaux ont ete realises a partir de deux montages reproduisant divers aspects de la degradation par le fretting. Un premier montage de fretting de type bille-plaque a ete entierement developpe a l'ETS et un second montage, de type fil-plaque a ete utilise en collaboration avec Hydro Quebec IREQ a Varennes. Plusieurs techniques de mesures et d'analyse relevant tant du domaine de la mecanique du contact que de la metallurgie ont ete utilisees pour traiter les resultats. L'influence du courant sur le taux d'usure et la force de friction a ete examinee pour divers materiaux de contacts. Des essais de fatigue thermique et electrique ont ete realises sur divers materiaux et lubrifiants de contact. Il a ete demontre que pour le domaine entre 100 mum et 1000 mum, le taux d'usure n'est pas le meme de 0 a 100 mum et au dela de 1000 mum. La plupart des materiaux evalues montrent un stade de comportement intermediaire dont le debut se situe entre 100 mum et 300 mum. Lorsque l'on substitut le courant CC a un courant CA de 60 Hz ou 400 HZ, la morphologie des debris aux abords de la zone de contact est differente. De plus, lors de la comparaison du vieillissement thermique par conduction versus par chauffage electrique de certains alliages sans plomb, il a ete montre qu'il pourrait y avoir une difference entre les deux en ce qui concerne le taux de croissance des phases intermetalliques.

Gagnon, Daniel

126

Organisation du produit de deux ensembles: Influence des interactions sociales entre pairs sur les procédures de résolution et les performances individuelles  

Microsoft Academic Search

Résumé  Cette recherche vise à étudier l'efficacité des confrontations socio-cognitives entre enfants sur leurs compétences à résoudre\\u000a des problèmes d'organisation de produits de deux ensembles. Elle est plus particulièrement centrée sur l'analyse du rôle des\\u000a conditions d'organisation de l'interaction et des mécanismes permettant de rendre compte des progrès individuels.\\u000a \\u000a \\u000a 67 enfants âgés de 5 à 6 ans ont été répartis entre

Agnés Blaye

1987-01-01

127

Soil Quality Indicators to Define Land Use in the Area of Native Forest of Entre Ríos, Argentina  

NASA Astrophysics Data System (ADS)

The main economic activity in the area of native forest of the province of Entre Ríos (Argentina) has long been the agricultural and/or livestock production, especially cattle breeding. In recent years, the proportion of agricultural crops in the rotations, especially that of soybean, has increased, thus leading to an increase in the need for land clearing to incorporate new lands for agricultural use. Most of these lands are considered marginal for agricultural use. In addition rice farming with irrigation is a critical part of the Entre Ríos economy. Defining and assessing soil quality indicators (SQI) that show the evolution of the soil with different uses and management systems is a way to contribute to the knowledge of soil quality. The aims of this study were to characterize the current land use and land tenure in the area of native forest of Entre Ríos, as well as to identify and select variables sensitive to agricultural and/or livestock use of the most representative soils of this area (indicators of the dynamic quality of the soil) and define the most appropriate land use according to land suitability and behavior of these indicators. We identified the most representative soil subgroups (corresponding to the orders Vertisols, Mollisols and Alfisols) and defined the production systems livestock-agricultural, agricultural-livestock, agricultural without irrigation, and rice crop irrigated with water from groundwater and surface reservoirs. We also determined the physical, physico-chemical, chemical and microbiological variables of the soil, and characterized the quality of the water for irrigation. We selected the SQI using Principal Components Analysis, to form a minimum data set (MDS). The change in the use of the land responded to a favorable economic situation for agriculture that started in the 1990's. The leasing and sharecropping schemes and the incidental contracts have become increasingly important, predominating over the undivided property. We obtained the MDS for twelve combinations of soil subgroups and production systems. The MDS for each of them presented between six and nine SQI. The indicators showed greater variation in the MDS by production system than by unit of land. Total organic carbon content (TOC) and the structural stability index (Is) were included in all the MDS. The rice systems showed high dependence on the quality of the irrigation water. We also found high fragility of some soil subgroups. The results suggest that rotations including pastures in a high proportion should be considered, especially in Alfisols and Vertisols. The native forest is considered as the basis of sustainable production systems for the study area. Thus, the land that has already been cleared or is about to be cleared should consider an agricultural and/or livestock use according to its productive capacity and its limitations.

Wilson, M. G.; Tasi, H. A.; Paz González, A.; Díaz, E. L.; Sasal, M. C.

2012-04-01

128

COMPARACIÓN ENTRE LAS PAPAYAS \\  

Microsoft Academic Search

The goal of this study was to make maturation scales for two papaya cultivars, of the Solo's group, the most important for exportation and for the internal market: 'Sunrise Solo' and 'Golden'. Fruits were harvested at seven different maturation stages in the tree, on comercial farming located at Linhares-ES, Brazil, based on peel color. It was established a visual maturation

O. Fonseca; Nilton Rocha Leal; Sérgio A. Cenci; Paulo R. Cecon; Ricardo E. Bressan-Smith

129

A Concepção de Universo entre Alunos do Ensino Médio de São Paulo e suas Fontes de Aquisição  

NASA Astrophysics Data System (ADS)

Nesse trabalho procurou-se identificar por meio de um questionário as concepções de Universo, de espaço e tempo que sustentam a visão de mundo de um grupo de 270 estudantes de Ensino Médio, pertencentes a três escolas de São Paulo. As questões relacionadas aos conhecimentos prévios dos estudantes permitiram constatar que há pouco conhecimento acerca dos temas investigados, destacando-se que apenas 20% dos alunos foram capazes de relacionar as semanas com as fases da lua, enquanto 28% associaram as estações do ano à inclinação do eixo de rotação da Terra e 23% tinham noções das distâncias entre objetos celestes próximos da Terra. Enquanto 56% conseguiram relacionar o Big Bang com a origem do Universo, verificou-se que 37% reconheciam ano-luz como unidade de distância e 60% concebiam o Sol como uma estrela. No que se refere às fontes de aquisição que proporcionaram esses conhecimentos, apesar de 60% dos alunos indicarem a escola como principal fonte dos conhecimentos de Ast! ronomia, verificou-se claramente que para a maioria dos alunos seus conceitos ainda são inadequados, havendo necessidade de aprimoramento da abordagem desses conteúdos, pois apesar de popular, a Astronomia ainda é veiculada de maneira pouco esclarecedora e com imprecisões. Nesse contexto, são discutidas algumas possíveis contribuições que podem ser dadas para o ensino de Astronomia pelo uso das ferramentas computacionais nas escolas.

Araújo, M. A. A.; Elias, D. C. N.; Amaral, L. H.; Araújo, M. S. T.; Voelzke, M. R.

2006-08-01

130

COOPERACIÓN Y CONFLICTOS AMBIENTALES LOCALES. ENTRE EMPRESAS, COMUNIDADES, NUEVOS MOVIMIENTOS SOCIALES Y EL PAPEL DEL GOBIERNO. EL CASO DE CERRO DE SAN PEDRO (MÉXICO)  

Microsoft Academic Search

El objetivo de este trabajo es analizar las relaciones de cooperación y conflicto entre una compañia minera y las comunidades, los Nuevos Movimientos Sociales y los tres niveles de gobierno involucrados. La compañia Minera inició operaciones para una mina a cielo abierto de oro y plata con el apoyo de oficiales de los gobiernos locales, estatales y federal. Los habitantes

José G. Vargas-Hernández

2007-01-01

131

LA CAPTACIÓN DE RECURSOS PRIVADOS ENTRE LAS ONGD ESPAÑOLAS: UNA APROXIMACIÓN PROBABILÍSTICA \\/ PRIVATE RESOURCES CAPTATION AMONG SPANISH ONGD: A PROBABILÍSTIC APPROXIMATION  

Microsoft Academic Search

La necesidad de recursos privados entre las ENL, tanto para su sostenimiento como para la realización de su labor requiere de estrategias organizativas cada vez más eficaces, por lo que el estudio del fundraising y su eficacia suscita un gran interés. En este trabajo, y basándonos en las conclusiones de estudios previos, pretendemos analizar la relación e influencia de una

M. B. Gutiérrez Villar; R. A. Araque Padilla; M. J Montero Simó

2009-01-01

132

MODELO MATEMÁTICO PARA ESTIMAR EL ESPACIAMIENTO ENTRE DRENES SUBTERRÁNEOS EN RÉGIMEN TRANSITORIO Mathematical Model for Estimating Spacing Between Subterranean Drains in Transitory Regime  

Microsoft Academic Search

Para el diseño de sistemas de drenaje subterráneo existen diferentes modelos, tanto para régimen permanente, como transitorio; sin embargo, la mayoría de ellos no se han obtenido para condiciones de suelo y clima semiáridas. Por lo tanto, este trabajo tuvo como objetivo desarrollar una ecuación empírica para régimen transitorio que permitiera determinar el espaciamiento entre drenes paralelos, considerando los intervalos

Pablo Miguel Coras-Merino

2006-01-01

133

La GRH et la représentation du travail, entre activité subjective et activité prescrite : pour une prise en compte des dynamiques professionnelles  

Microsoft Academic Search

La communication entend interroger les rapports entre la Gestion des Ressources Humaines et le travail selon une perspective locale. Loin des débats philosophiques sur l'avenir du travail en général dans nos sociétés, elle insiste sur le rôle de la GRH quant à une maîtrise locale du sens du travail. Cette perspective n'est pas particulièrement nouvelle, et de nombreux travaux ont

Jean-Baptiste Suquet

2006-01-01

134

Bancos de Genes de Plantas: Seguridad Alimenticia  

NSDL National Science Digital Library

The issue-focused, peer-reviewed article shows how genebanks are like an insurance policy for the future of agriculture, for they: conserve the diversity of plant species, offer resources for breeding of hardier crop varieties, provide food solutions in times of disaster, and safeguard food supplies for future generations.

Geoffrey C. Hawtin and Jeremy Cherfas (International Plant Genetic Resources Institute;)

2003-04-01

135

In planta transformation of Arabidopsis thaliana  

Microsoft Academic Search

Transformants of Arabidopsis thaliana can be generated without using tissue culture techniques by cutting primary and secondary inflorescence shoots at their bases and inoculating the wound sites with Agrobacterium tumefaciens suspensions. After three successive inoculations, treated plants are grown to maturity, harvested and the progeny screened for transformants on a selective medium. We have investigated the reproducibility and the overall

Vesna Katavic; George W. Haughn; Darwin Reed; Marilyn Martin; Ljerka Kunst

1994-01-01

136

L’influence du degré d’aversion à l’inégalité du décideur sur sa perception des inégalités intragroupes et intergroupes : une application de l’alpha décomposition aux salaires de la France entre 1995 et 2005  

Microsoft Academic Search

Nous proposons dans cette recherche de mettre en avant le rôle capital joué par les préférences du décideur sur sa perception des inégalités intragroupes et intergroupes. Une application réalisée à partir des salaires observés en France entre 1995 et 2005 révèle notamment de grands écarts de valeurs entre les différents indicateurs choisis pour évaluer l’évolution des disparités salariales sur la

Pauline MORNET; Françoise SEYTE; Michel TERRAZA

2012-01-01

137

Entre el museo y el teatro: Oportunidades didácticas de la entrada real de Ana de Austria en Madrid  

Microsoft Academic Search

El despliegue iconográfico y escénico de la entrada real de Ana de Austria en Madrid (1570) supone una sólida plataforma propagandística para Felipe II, a la vez que una significativa oportunidad didáctico-artística para su audiencia. A medio camino entre el festival político y el popular, el festejo celebra no sólo la presencia de los monarcas, sino también la de una

2009-01-01

138

Entre el museo y el teatro: Oportunidades didácticas de la entrada real de Ana de Austria en Madrid  

Microsoft Academic Search

:El despliegue iconográfico y escénico de la entrada real de Ana de Austria en Madrid (1570) supone una sólida plataforma propagandística para Felipe II, a la vez que una significativa oportunidad didáctico-artística para su audiencia. A medio camino entre el festival político y el popular, el festejo celebra no sólo la presencia de los monarcas, sino también la de una

2009-01-01

139

Étude physico-chimique des réactions entre oxydes d'azote Application à l'analyse de ces gaz en sortie de systèmes de combustion  

NASA Astrophysics Data System (ADS)

Analysing gaseous nitrogen oxides emissions at the combustion system outlet (exhaust pipe, central heating, glass kiln,...) are a current environmental topic. Yet, studying these pollutant involves two difficulties : first a great number of NOx do exist, and secondly the system can shift quickly. The objective of this work consists of examining results of literature and studying more specially NO/NO2/O2 system to clarify these problems. For this purpose theoretical and experimental works concerning kinetics and thermodynamics of NOx transformations have been carried out. The NOx maximum starting concentration reaches 1000 ppm in an oxygen-containing atmosphere and with temperature comprised between 25 circC and 1000 circC. These parameters are representative of real combustion conditions. An apparatus has been built to determine both experimental equilibrium and kinetic constants for the reaction 2 NO + O2 = 2 NO2. Rate constants have been measured for temperature lower than 300 circC. Above 300 circC, the catalytic influence of the reactor walls has been clearly established. For each temperature, NOx concentrations at equilibrium give experimental thermodynamic data, in agreement with the theoretical approach. Analyser les émanations d'oxydes d'azote gazeux issus des systèmes de combustion (moteurs automobiles, chauffage urbain, fours de verreries,...) constitue un objectif actuel de recherche concernant l'environnement. L'étude de ces polluants présente une double difficulté. D'une part, ils existent sous de multiples formes, d'autre part de nombreux facteurs viennent influer sur la vitesse de transformation de ces gaz (température, géométrie et nature du réacteur, temps,...). Ce travail a été mené pour effectuer une mise au point des recherches sur le sujet et étudier plus particulièrement aux niveaux thermodynamique et cinétique le mélange gazeux NO/NO2/O2. Un dispositif a été mis au point afin de mesurer expérimentalement les vitesses de réaction pour des paramètres expérimentaux représentatifs des atmosphères générées par les systèmes de combustion (teneur en NOx : 1000 ppm, présence d'oxygène, température comprise entre 25 circC et 1000 circC). Les constantes cinétiques ont ainsi été déterminées pour des températures inférieures à 300 circC. L'influence catalytique de la paroi du réacteur a été mise en évidence au delà de cette température. Les valeurs concernant les équilibres thermodynamiques entre les NOx ont également pu être validées expérimentalement.

Leblanc, E.; Jokela, K.; Perier-Camby, L.; Thomas, G.

1999-05-01

140

In planta mutagenesis of Src homology 3 domain-like fold of NdhS, a ferredoxin-binding subunit of the chloroplast NADH dehydrogenase-like complex in Arabidopsis: a conserved Arg-193 plays a critical role in ferredoxin binding.  

PubMed

Chloroplast NADH dehydrogenase-like (NDH) complex mediates cyclic electron transport around photosystem I and chlororespiration in angiosperms. The Src homology 3 domain (SH3)-like fold protein NdhS/CRR31 is an NDH subunit that is necessary for high affinity binding of ferredoxin, indicating that chloroplast NDH functions as a ferredoxin:plastoquinone oxidoreductase. However, the mechanism of the interaction between NdhS and ferredoxin is unclear. In this study, we analyzed their interaction in planta by using site-directed mutagenesis of NdhS. In general, binding of ferredoxin to its target proteins depends on electrostatic interaction. In silico analysis predicted the presence of a positively charged pocket in the SH3-like domain of NdhS, where nine charged residues are highly conserved among plants. Systematic alteration of these sites with neutral glutamine revealed that only arginine 193 was required for high NDH activity in vivo. Further replacement of arginine 193 with negatively charged aspartate or glutamate or hydrophobic alanine significantly decreased the efficiency of ferredoxin-dependent plastoquinone reduction by NDH in ruptured chloroplasts. Similar results were obtained in in vivo analyses of NDH activity and electron transport. From these results, we propose that the positive charge of arginine 193 in the SH3-like domain of NdhS is critical for electrostatic interaction with ferredoxin in vivo. PMID:24225949

Yamamoto, Hiroshi; Shikanai, Toshiharu

2013-12-20

141

Analyse quantitative des foraminifères benthiques actuels de la marge atiantique marocaine entre Cap Draˆa et Cap Juby: reponses fauniques aux changements de l'environnement  

NASA Astrophysics Data System (ADS)

La population des foraminifères benthiques actuels de la marge atlantique marocaine, entre Cap Draˆa et Cap Juby, aétéétudiée dans 58 prélèvements parmi 430 répartis suivant un système de radiales perpendiculaireàla ligne de rivage. Quarante-sept espèces parmi 104 appartenantà58 genres et 28 familles ontétéreconnues. Les abondances absolues de chacune des espèces ontétécomparées dans les différents prélèvements ainsi que les indices biocénotiques (richesse spécifique, abondance, indice de pélagisme, nombre d'espèces benthiques enroulées, nombre d'espèces benthiques costulées) et les paramètres abiotiques (nature de substrat et profondeur). L'analyse factorielle des correspond ances, complétée par la classification hiérarchique et la projection des paramètres biotiques et abiotiques en tant que colonnes supplémentaires ont révéléclue la profondeur est le facteur principal de la distribution des espèces et des prélèvements. En effet, elle oppose les associations d'espèces infralittorales enroulées lisses aux associations d'espècesépibathyales rectilignes ornées, les espèces circalittorales occupent une position intermédiaire. Le facteur secondare correspondàla nature du substrat, oppose les associations d'espèces vasicoles aux associations d'espèces sabulicoles aussi bien celles de l'environnement infralittoral que celles de l'épibathyal.

Rezqi, H.; Oujidi, M.; Boutakiout, M.; Labraimi, M.

2000-02-01

142

Le renforcement de l'interface entre les services de sant? publique et de premi?re ligne : enjeux et pistes de solution  

PubMed Central

Le développement de liens étroits entre la santé publique et les services cliniques, notamment ceux offerts par les médecins de famille œuvrant en première ligne, est prôné dans tous systèmes de santé occidentaux. On suppose que les collaborations formant une telle interface ont des impacts positifs à la fois sur la qualité des soins, sur le fardeau des maladies et sur l'équité dans le système de santé. Si les acteurs des deux domaines admettent le bien-fondé de l'interface et favorisent en principe son développement, plusieurs barrières nuisent aux collaborations dans la réalité. Or, peu est connu sur ces barrières dans le système de santé québécois. Cette étude vise à répondre à ce manque d'information en étudiant l'interface à partir d'une perspective organisationnelle. Deux cadres conceptuels ont été utilisés, soit la typologie de Lasker (1997) et les archétypes de Hinings et Greenwood (1988). L'analyse met en évidence deux des six formes de collaboration proposées par la typologie utilisée, soit la coordination des services aux individus et la mise à profit des rencontres cliniques pour les fins de la santé publique. Les activités associées à ces formes de collaboration, qui sont importantes eu égard au mandat de la santé publique, comportent un intérêt essentiellement pour la santé publique et sont déterminées en pratique unilatéralement par cette dernière. En outre, le manque de coordination des activités qui impliquent une collaboration avec les médecins constitue un obstacle au développement de telles activités en créant des irritants pour les médecins. Il y a donc, dans le système de santé québécois, des possibilités de développement de l'interface là où la collaboration se fait également au profit du travail clinique et là où elle tient compte des contraintes du milieu clinique.

Paquette, Daniel; Reinharz, Daniel

2009-01-01

143

Nós e as plantas: ontem e hoje1  

Microsoft Academic Search

The plants and us: past and present). Green areas in cities and trees growing on streets and squares of urban sites are features that only recently acquired relevance in the western world. It seems that formerly urban inhabitants did not value a close proximity with plants. In the present paper it is suggested that this is a consequence of a

ANTONIO SALATINO

144

Elucidation and in planta reconstitution of the parthenolide biosynthetic pathway.  

PubMed

Parthenolide, the main bioactive compound of the medicinal plant feverfew (Tanacetum parthenium), is a promising anti-cancer drug. However, the biosynthetic pathway of parthenolide has not been elucidated yet. Here we report on the isolation and characterization of all the genes from feverfew that are required for the biosynthesis of parthenolide, using a combination of 454 sequencing of a feverfew glandular trichome cDNA library, co-expression analysis and metabolomics. When parthenolide biosynthesis was reconstituted by transient co-expression of all pathway genes in Nicotiana benthamiana, up to 1.4?gg(-1) parthenolide was produced, mostly present as cysteine and glutathione conjugates. These relatively polar conjugates were highly active against colon cancer cells, with only slightly lower activity than free parthenolide. In addition to these biosynthetic genes, another gene encoding a costunolide and parthenolide 3?-hydroxylase was identified opening up further options to improve the water solubility of parthenolide and therefore its potential as a drug. PMID:24704560

Liu, Qing; Manzano, David; Tani?, Nikola; Pesic, Milica; Bankovic, Jasna; Pateraki, Irini; Ricard, Lea; Ferrer, Albert; de Vos, Ric; van de Krol, Sander; Bouwmeester, Harro

2014-05-01

145

DETERMINAÇÃO DE NUTRIENTES MINERAIS EM PLANTAS MEDICINAIS 1  

Microsoft Academic Search

SUMMARY DETERMINATION OF MINERALS IN MEDICINAL PLANTS. The use of vegetables has become widely spread as nourishment, medicinal and cosmetic purposes in recent years. Due to the importance of the analytical study of this class of plants, and considering the growing interest about their inorganic composition that can be represented by the significant number of publications during the last years,

Maria Mozarina; Beserra ALMEIDA; Maria de Fátima; Gomes LOPES; Célia Maria Diógenes NOGUEIRA; Carlos Emanuel de Carvalho; Noélia Maria Tavares de MORAIS

146

Le transfert de connaissances entre les mathematiques et les sciences. Une etude exploratoire aupres d'eleves de 4e secondaire  

NASA Astrophysics Data System (ADS)

Au moment ou dans plusieurs pays on travaille a refondre les programmes d'etudes, tant au primaire qu'au secondaire, l'interet pour le transfert renait. Un des concepts fondamentaux en apprentissage consiste en l'habilete a reutiliser de facon consciente et efficace un acquis d'une situation a une autre situation. Cette recherche emane de preoccupations professionnelles au moment ou le chercheur etait enseignant au secondaire. Au cours de ces annees, il lui a ete possible de constater que plusieurs eleves percevaient difficilement les liens presents entre les disciplines mathematiques et scientifiques. Des travaux en psychologie cognitive et plus particulierement selon une perspective du traitement de l'information ont servi de cadre de reference pour evaluer et analyser les capacites de transfert aupres d'eleves de 4e secondaire. Ce cadre de reference permet de formuler le principal objectif qui est de mieux comprendre le processus de transfert chez des eleves en situation de resolution de problemes scientifiques. Cette these s'interesse donc au transfert en tant que phenomene important du processus d'apprentissage au sens de l'integration. La methode de recherche choisie, de nature qualitative, est principalement axee sur l'evaluation de la capacite a transferer des connaissances lors d'une epreuve et d'un entretien. Pour evaluer ce potentiel de transfert, nous avons elabore deux outils: une epreuve en mathematiques et en sciences et un guide d'entretien. Pour la passation de l'epreuve, le chercheur a pu compter sur la collaboration de 130 sujets provenant de deux ecoles. L'entretien complete la prise de donnees avec 13 sujets ayant accepte de poursuivre l'etude. Les donnees recueillies par ces instruments font ensuite l'objet d'une analyse de contenu. En premier lieu, les verbatims de l'epreuve et de l'entretien ont ete transcrits, puis codifies. La correction des reponses fournies pour les problemes resolus s'est faite a partir d'une grille d'analyse qualitative et adaptee de la litterature (Thouin, 1995). Une seconde serie d'analyses permettant de categoriser les reponses selon la typologie des connaissances declaratives, procedurales et conditionnelles complete la prise de donnees. Nos resultats indiquent que les sujets sont tres influences par des elements de surface, principalement lorsqu'il s'agit de problemes auxquels ils ne sont pas habitues. En l'absence de connaissances de base, plusieurs sujets vont tendre vers des propositions de solution "pratico-pratique" provenant de leur vecu: cela nous apparait d'importance d'un point de vue didactique et en matiere de transfert. Lors des entretiens realises un mois plus tard, les sujets ont eprouve de la difficulte a se rappeler le contenu de l'epreuve. Et lorsqu'il y avait un rappel, celui-ci etait superficiel et surtout axe sur le contenu ou le contexte d'un probleme. La plupart des sujets ne pouvait nommer que deux ou trois elements (des problemes en mathematiques, en sciences physiques, le probleme de la fenetre, le probleme du laser, etc.). Nos resultats confirment ce que plusieurs chercheurs (Julo, 1995, Jonnaert et Vander Borght, 1999; Richard et al., 1990) qui s'interessent aux questions de l'apprentissage admettent aujourd'hui: l'eleve ne travaille jamais sur la situation proposee par l'enseignant, mais bien sur la representation qu'il s'en est construite. Au plan methodologique, cette recherche est interessante par la variete des sources de collecte de donnees utilisees, par l'application d'outils methodologiques et d'analyses originaux tires de la recherche et de la pratique. Du cote theorique, il resulte de cette etude une meilleure comprehension du processus de transfert des connaissances mathematiques vers les sciences physiques. Finalement, aux plans didactique et pedagogique, cette recherche alimente la reflexion sur l'apprentissage et l'enseignement des sciences au secondaire. Elle fait ressortir que les mathematiques sont importantes dans la mobilisation de certaines connaissances scientifiques et que l'enseignant peut et devrait jouer un

Samson, Ghislain

2003-06-01

147

Competition entre supraconductivite et magnetisme au voisinage de la transition de Mott dans le conducteur organique quasi-bidimensionnel k-(BEDT-TTF)2copper[N(CN)2]bromine  

NASA Astrophysics Data System (ADS)

Les conducteurs organiques quasi-bidimensionnels kappa-ET2X presentent d'importantes similitudes avec les SCHT telles qu'une phase isolant de Mott, un regime de pseudogap et un etat supraconducteur. L'etude de leurs proprietes apparait donc complementaire. Parmi les interrogations persistantes concernant la physique de ces systemes, l'origine du (ou des) processus exotique d'appariement, responsable de la supraconductivite est le sujet suscitant l'interet le plus marque dans la communaute. L'hypothese d'un mecanisme lie a la proximite d'un etat antiferromagnetique est privilegiee. Une etape importante dans la resolution de cette problematique est l'identification de la symetrie du parametre d'ordre. D'apres de nombreux travaux sur les systemes fortement correles, la sonde ultrasonore, de par sa sensibilite aux excitations de quasiparticule a basse temperature, est consideree comme particulierement adaptee a l'etude de cette propriete. Cependant, son emploi necessite l'utilisation d'un compose metallique a basse temperature et completement supraconducteur. Le compose metallique organique kappa-ET 2Cu[N(CN)2]Br presente toutes les caracteristiques necessaires a l'etude de cette propriete. En effet, il est situe loin de la transition du premier ordre de Mott et est completement supraconducteur. De facon surprenante, ce systeme semble se coupler fortement avec le reseau ce qui augmente significativement la sensibilite de cette sonde aux proprietes du gaz electronique. Cependant, des difficultes techniques importantes, liees a la nature intrinseque de ce materiau, doivent etre surmontees pour proceder a des mesures suivant differentes polarisations. La presente etude a profondement modifie notre comprehension de ce systeme. En effet, ces mesures ont permis de constater que le kappa-ET2Cu[N(CN)2]Br est un compose qui est situe en bordure de la zone de coexistence entre la supraconductivite et le magnetisme, ce qui constitue un resultat totalement inattendu. De plus, la variation judicieuse du cycle thermique s'est averee etre equivalente a une modification de la pression chimique. Cette derniere est modifiee par l'intermediaire d'une relaxation structurale autour de 85 K appelee la transition de verre d'ethylenes. Cela nous a permis de suivre l'evolution de cette coexistence en s'approchant de la transition de premier ordre, et ainsi de statuer sur la competition entre la supraconductivite et le magnetisme ainsi que sur l'existence d'une separation de phase d'ordre macroscopique. De plus, nous avons observe une anisotropie similaire sur les mesures de vitesse ultrasonore entre le regime de pseudogap et la supraconductivite. Ce resultat tend a confirmer l'existence d'une physique commune entre le regime de pseudogap et l'etat supraconducteur. Le regime de pseudogap, encore meconnu a ce jour, est probablement relie a des fluctuations antiferromagnetiques, dont l'origine pourrait etre un emboitement de la surface de Fermi quasi-unidimensionnelle de ce compose, ou bien relie a la proximite de la physique de Mott. Enfin, l'analyse de la symetrie du parametre d'ordre supraconducteur, qui est probablement de type s+d, tend a demontrer que les processus de couplage interplan sont d'une importance cruciale. L'approche theorique de Hubbard purement 2D dans le plan conducteur semble donc insuffisante pour la recherche du mecanisme d'appariement.

Fournier, David

148

Bojayá: entre el miedo y los medios  

Microsoft Academic Search

El día en que en la iglesia de Bojayá las FARC hicieron estallar una pipeta de gas que mató a 119 civiles y dejó heridas a otras 90, ese municipio en la ribera del Atrato dejó de ser un desconocido pueblo de la geografía colombiana. Los ojos de la comunidad nacional e internacional se volcaron allí. La masacre se convirtió

Aída Carolina Lancheros Ruiz; Julián Andrés Rincón Ortiz

149

Mundos Torcidos: diferenças entre crioulos e africanos na dinâmica da construção de comunidades de grandes propriedades no Sudeste brasileiro do século XIX. Twisted worlds: differences between African and Creole in the dynamics of building communities of large properties in the Southeast of Brazil of the nineteenth century  

Microsoft Academic Search

Resumo: Este trabalho tem como objetivo identificar e analisar elementos constitutivos das relações entre grupos de escravos oriundos da diáspora africana e seus pares nascidos no Brasil, em busca de um padrão cultural e de fundamentos morais que organizariam as diferenças instauradas no cativeiro, buscando compreender um pouco mais a dinâmica do manuseio de patrimônios imateriais, quer trazidos na travessia

Carlos Engemann

150

COMERCIALIZAÇÃO DE FLORES E PLANTAS ORNAMENTAIS NO SEGMENTO VAREJISTA NO MUNICÍPIO DE LAVRAS\\/MG Flowes and ornamentals plantas commercialization in retailer segment at Lavras\\/MG  

Microsoft Academic Search

Ornamentals plants and flowers Brazilian market has been presenting increase perspectives and consequent increment for the main segments of productive system: production, distribution and commercialization. This optimist prevision has been attracting new undertakes occasioning an increase of competition and the search necessity for new products and services. To understand the ornamental plants and flower new tendency and to analyze the

Marina Ceratti; Patrícia Duarte; Oliveira Paiva; Magno de Sousa; Thaísa Silva Tavares

151

In planta multiplication and graft transmission of ‘ Candidatus Liberibacter asiaticus’ revealed by Real-Time PCR  

Microsoft Academic Search

The bacterium Candidatus Liberibacter asiaticus (CLas) is associated with huanglongbing (HLB) in citrus in many countries. Despite the fact that many\\u000a characteristics of the disease are known, the rate of multiplication of the bacterium within an infected tree is still poorly\\u000a understood. To study this feature, we used the quantitative Real-Time polymerase chain reaction (Q-PCR) assay to follow and\\u000a to

H. D. Coletta-Filho; E. F. Carlos; K. C. S. Alves; M. A. R. Pereira; R. L. Boscariol-Camargo; A. A. de Souza; M. A. Machado

2010-01-01

152

Engineered Tobacco mosaic virus mutants with distinct physical characteristics in planta and enhanced metallization properties.  

PubMed

Tobacco mosaic virus mutants were engineered to alter either the stability or surface chemistry of the virion: within the coat protein, glutamic acid was exchanged for glutamine in a buried portion to enhance the inter-subunit binding stability (E50Q), or a hexahistidine tract was fused to the surface-exposed carboxy terminus of the coat protein (6xHis). Both mutant viruses were expected to possess specific metal ion affinities. They accumulated to high titers in plants, induced distinct phenotypes, and their physical properties during purification differed from each other and from wild type (wt) virus. Whereas 6xHis and wt virions contained RNA, the majority of E50Q protein assembled essentially without RNA into rods which frequently exceeded 2 ?m in length. Electroless deposition of nickel metallized the outer surface of 6xHis virions, but the central channel of E50Q rods, with significantly more nanowires of increased length in comparison to those formed in wtTMV. PMID:21310199

Kadri, Anan; Maiss, Edgar; Amsharov, Nadja; Bittner, Alexander M; Balci, Sinan; Kern, Klaus; Jeske, Holger; Wege, Christina

2011-04-01

153

Actividad antifungica de extractos de plantas usadas en medicina popular en Argentina  

Microsoft Academic Search

Fungi may cause very serious diseases in humans specially in immunosuppressed patients. In this study, extracts of 10 plants used in popular medicine in Argentine were assayed for in vitro antifungal activity against 4 fungal strains. Out of all the plants tested, Larrea divaricata Cav, Gnaphalium gaudichaudianum D.C, Baccharis trimera Less and Schinus terebenthifolius proved to have antifungal activity.

Roberto Davicino; María Aída Mattar; Yolanda Angelina Casali; Silvia Graciela Correa; Elisa Margarita Pettenati; Blas Micalizzi

154

The Use of Bioluminescence for Monitoring in planta Growth Dynamics of a Pseudomonas syringae Plant Pathogen  

Microsoft Academic Search

The use of bioluminescence was evaluated as a tool to study Pseudomonas syringae population dynamics in susceptible and resistant plant environments. Plasmid pGLITE, containing the luxCDABE genes from Photorhabdus luminescens, was introduced into Pseudomonas syringae pv. phaseolicola race 7 strain 1449B, a Gram-negative pathogen of bean (Phaseolus vulgaris). Bacteria recovered from plant tissue over a five-day period were enumerated by

Christopher D. Paynter; Vyvyan C. Salisbury; Dawn L. Arnold; Robert W. Jackson

2006-01-01

155

Staphylococcal abscess caused by trauma with a rosebush aculeus (Plantae, Rosaceae): apropos of a case*  

PubMed Central

Cutaneous abscess is a localized collection of pus in the dermis and subcutaneous tissue usually caused by trauma. The authors report the case of a 30-year-old male patient, gardener, that presents an ulcerated plaque in the third right finger, caused by an aculeus plant wound. The examination of the lesion's exudate ruled out the existence of fungi and showed the presence of Staphylococcus aureus. The authors emphasize the sporotrichosis as an important differential diagnosis, especially in endemic areas, and the indication of the exudate culture is discussed.

Bernardes Filho, Fred; Alves, Andreia Oliveira; Martins, Gustavo; Sasso, Leticia Soares; Gama, Carolina Mendonca; Cenci, Gardenia Borges

2013-01-01

156

EVALUACIÓN DE ALTERNATIVAS PARA LA LOCALIZACIÓN DE PLANTAS DE RECICLAJE DE RAEE EN ESPAÑA  

Microsoft Academic Search

As a consequence of new European legal regulations for treatment of waste electrical and electronic equipment (WEEE), recycling plants have to be installed in Spain. In this context, this contribution provides the decision maker with a ranking of Spanish municipalities according to their appropriateness for the installation of these plants. In order to rank the alternatives, the discrete multi-criteria decision

D. Queiruga; J. González-Benito

157

The DNA damage response signaling cascade regulates proliferation of the phytopathogenic fungus Ustilago maydis in planta.  

PubMed

In the phytopathogenic fungus Ustilago maydis, the dikaryotic state dominates the period of growth occurring during the infectious phase. Dikaryons are cells in which two nuclei, one from each parent cell, share a single cytoplasm for a period of time without undergoing nuclear fusion. In fungal cells, maintenance of the dikaryotic state requires an intricate cell division process that often involves the formation of a structure known as the clamp connection as well as the sorting of one of the nuclei to this structure to ensure that each daughter dikaryon inherits a balance of each parental genome. Here, we describe an atypical role of the DNA damage checkpoint kinases Chk1 and Atr1 during pathogenic growth of U. maydis. We found that Chk1 and Atr1 collaborate to control cell cycle arrest during the induction of the virulence program in U. maydis and that Chk1 and Atr1 work together to control the dikaryon formation. These findings uncover a link between a widely conserved signaling cascade and the virulence program in a phytopathogen. We propose a model in which adjustment of the cell cycle by the Atr1-Chk1 axis controls fidelity in dikaryon formation. Therefore, Chk1 and Atr1 emerge as critical cell type regulators in addition to their roles in the DNA damage response. PMID:21478441

de Sena-Tomás, Carmen; Fernández-Álvarez, Alfonso; Holloman, William K; Pérez-Martín, José

2011-04-01

158

Kinetics of leaf oxygen uptake represent in planta activities of respiratory electron transport and terminal oxidases.  

PubMed

We present, for the first time, the oxygen response kinetics of mitochondrial respiration measured in intact leaves (sunflower and aspen). Low O(2) concentrations in N(2) (9-1500 ppm) were preset in a flow-through gas exchange measurement system, and the decrease in O(2) concentration and the increase in CO(2) concentration as result of leaf respiration were measured by a zirconium cell O(2) analyser and infrared-absorption CO(2) analyser, respectively. The low O(2) concentrations little influenced the rate of CO(2) evolution during the 60-s exposure. The initial slope of the O(2) uptake curve on the dissolved O(2) concentration basis was relatively constant in leaves of a single species, 1.5 mm s(-1) in sunflower and 1.8 mm s(-1) in aspen. The apparent K(0.5)(O(2)) values ranged from 0.33 to 0.67 microM in sunflower and from 0.33 to 1.1 microM in aspen, mainly because of the variation of the maximum rate, V(max) (leaf temperature 22 degrees C). The initial slope of the O(2) response of respiration characterizes the catalytic efficiency of terminal oxidases, an important parameter of the respiratory machinery in leaves. The plateau of the response characterizes the activity of the mitochondrial electron transport chain and is subject to regulations in accordance with the necessity for ATP production. The relatively low oxygen conductivity of terminal oxidases means that in leaves, less than 10% of the photosynthetic oxygen can be reassimilated by mitochondria. PMID:18251919

Laisk, Agu; Oja, Vello; Eichelmann, Hillar

2007-09-01

159

IMPORTANCIA ETNOBOTÁNICA DE UNA PLANTA VASCULAR SIN SEMILLA EN MÉXICO: Equisetum  

Microsoft Academic Search

Ethnobotany is the branch of human knowledge that studies the relationship between plants and human. In Mexico, angiosperms have been mostly studied. However, there are seedless plants such as the genus Equisetum that has an important cultural value as evidenced in several communities, mainly due to its biochemical properties. In this paper we presented a review of bibliographical information supplemented

Juan Carlos Gallardo-Pérez; María de Lourdes Esparza-Aguilar; Armando Gómez-Campos

160

ESTIMATIVA DA ÁREA FOLIAR DE PLANTAS DE LIMA ÁCIDA 'TAHITI' USANDO MÉTODOS NÃO-DESTRUTIVOS1  

Microsoft Academic Search

The objective of this study was to evaluate non-destructive methods of estimating total leaf area of young 'Tahiti' lime (Citrus latifolia Tan.) plants grown in the field. Information of biometrical variables of 28 young plants (0.07 to 1.44 m2) and digitized image of front area of each plant (plant silhouette) were used. These variables were correlated to the direct measurements

MAURÍCIO ANTONIO; COELHO FILHO; LUIZ ROBERTO ANGELOCCI; MARCOS ROBERTO; BAPTISTA VASCONCELOS; EUGÊNIO FERREIRA COELHO

161

In Planta Proteomics and Proteogenomics of the Biotrophic Barley Fungal Pathogen Blumeria graminis f. sp. hordei*  

PubMed Central

To further our understanding of powdery mildew biology during infection, we undertook a systematic shotgun proteomics analysis of the obligate biotroph Blumeria graminis f. sp. hordei at different stages of development in the host. Moreover we used a proteogenomics approach to feed information into the annotation of the newly sequenced genome. We analyzed and compared the proteomes from three stages of development representing different functions during the plant-dependent vegetative life cycle of this fungus. We identified 441 proteins in ungerminated spores, 775 proteins in epiphytic sporulating hyphae, and 47 proteins from haustoria inside barley leaf epidermal cells and used the data to aid annotation of the B. graminis f. sp. hordei genome. We also compared the differences in the protein complement of these key stages. Although confirming some of the previously reported findings and models derived from the analysis of transcriptome dynamics, our results also suggest that the intracellular haustoria are subject to stress possibly as a result of the plant defense strategy, including the production of reactive oxygen species. In addition, a number of small haustorial proteins with a predicted N-terminal signal peptide for secretion were identified in infected tissues: these represent candidate effector proteins that may play a role in controlling host metabolism and immunity.

Bindschedler, Laurence V.; Burgis, Timothy A.; Mills, Davinia J. S.; Ho, Jenny T. C.; Cramer, Rainer; Spanu, Pietro D.

2009-01-01

162

Evite los Conceptos Erróneos cuando Enseñe sobre las Plantas  

NSDL National Science Digital Library

The resource is useful for teacher's professional development by alerting educators to many plant misconceptions in teaching literature. In the thought provoking, peer reviewed resource fifty misconceptions are identified. Some misconceptions are easier to identify because they are oversimplifications, overgeneralizations, or misidentifications. Others are more difficult to identify because they are obsolete concepts and terms or flawed research.

David R. Hershey (biology education consultant;)

2005-05-01

163

Arabidopsis thaliana Root Surface Chemistry Regulates in Planta Biofilm Formation of Bacillus subtilis.  

PubMed

Among the various rhizospheric interactions, plant root-microbe interactions are very important both economically and ecologically. The interaction of plant roots with plant growth promoting rhizobacteria (PGPR) have been studied in case of symbiotic organisms. However, the knowledge on interaction with other PGPRs such as biocontrol Bacillus sps. is vastly unexplored. Especially the complex root surface chemistry and its effect on modulating the bacterial growth and association with the root system has not been investigated. Recently, by adopting a systematic stepwise experimental approach we unraveled the importance of root plane chemistry on the colonization and biofilm formation by B. subtilis, an important biocontrol-PGPR. This study may further increase our understanding in the field of rhizosphere biology and area of root secretions and their possible role in plant microbe interactions. PMID:19704655

Rudrappa, Thimmaraju; Bais, Harsh P

2007-09-01

164

In Planta Visualization of Protein Interactions Using Bimolecular Fluorescence Complementation (BiFC).  

PubMed

INTRODUCTIONBimolecular fluorescence complementation (BiFC) analysis enables direct visualization of protein-protein interactions in living cells. This method has been successfully adapted to a variety of expression systems in different organisms. BiFC is based on the formation of a fluorescent complex by fragments of the enhanced yellow fluorescent protein (eYFP) when brought together by the interaction of two associating proteins fused to these fragments. Interaction of these proteins restores fluorescence and allows the visualization of spatial localization patterns of protein complexes. Absence of interaction prevents reassembly of the fluorescent protein and results only in background fluorescence. The specificity of bimolecular fluorescence complementation must be confirmed by parallel analysis of proteins in which the interaction interface has been mutated. This protocol describes the Agrobacterium-mediated transient expression protocol for BiFC assays in Nicotiana benthamiana leaf cells. This method exhibits a high transformation rate (up to 90% of the cells) and allows the simultaneous expression of multiple proteins in single cells. Therefore, this expression system enables colocalization analyses of fluorescently labeled proteins with the formation of BiFC complexes for determination of cellular complex localization. In addition, protein interaction assays in N. benthamiana leaves permit the investigation of protein interactions at different time points of expression, allow analysis of proteins that are normally toxic in protoplasts, and enable comparative protein interaction investigation in epidermal cells as well as in mesophyll protoplasts. PMID:21356813

Waadt, Rainer; Kudla, Jörg

2008-01-01

165

EFEITO DE EXTRATOS AQUOSOS DE PLANTAS NA OVIPOSIÇÃO DA TRAÇA-DAS-CRUCÍFERAS, EM COUVE (1)  

Microsoft Academic Search

RESUMO Avaliou-se o efeito de extratos aquosos de Achillea millefolium L. (folhas), Azadirachta indica A. Juss. (folhas), Bidens pilosa L. (folhas, frutos e ramos), Bougainvillea glabra Choisy (folhas), Chenopodium ambrosioides L. (folhas, frutos e ramos), Datura suaveolens Humb & Bonpl. ex. Willd (folhas), Enterolobium contortisilliquum (Vell.) Morong (frutos), Mentha crispa L. (folhas e ramos), Nicotiana tabacum L. (folhas), Piper nigrum

CESAR AUGUSTO; MANFRÉ MEDEIROS; ARLINDO LEAL

2005-01-01

166

The signal transduction pathways controlling in planta tuberization in potato: an emerging synthesis  

Microsoft Academic Search

Tuberization is one of the multiple outputs of a single-input phytochrome B sensory system, involving several regulatory genes.\\u000a Phytochrome B- and GA-mediated photoperiodic perception occurs in the leaf, and then the RNA acts as a systemic signal in\\u000a the long-distance signaling pathway to initiate tuberization in the subapical region of an underground stolon. There is good\\u000a evidence that flowering and

Debabrata Sarkar

2008-01-01

167

Manual of Meat Processing Plants (Manual de Plantas Procesadoras de Carne).  

National Technical Information Service (NTIS)

This manual was prepared by specialists on meat inspection from the U.S. Dept. of Agriculture as an aid in training inspectors for meat processing industries. It focuses on the sanitary aspects of meat work and follows the U.S. Dept. of Agriculture recomm...

1980-01-01

168

In planta localisation patterns of MADS domain proteins during floral development in Arabidopsis thaliana  

PubMed Central

Background MADS domain transcription factors play important roles in various developmental processes in flowering plants. Members of this family play a prominent role in the transition to flowering and the specification of floral organ identity. Several studies reported mRNA expression patterns of the genes encoding these MADS domain proteins, however, these studies do not provide the necessary information on the temporal and spatial localisation of the proteins. We have made GREEN FLUORESCENT PROTEIN (GFP) translational fusions with the four MADS domain proteins SEPALLATA3, AGAMOUS, FRUITFULL and APETALA1 from the model plant Arabidopsis thaliana and analysed the protein localisation patterns in living plant tissues by confocal laser scanning microscopy (CLSM). Results We unravelled the protein localisation patterns of the four MADS domain proteins at a cellular and subcellular level in inflorescence and floral meristems, during development of the early flower bud stages, and during further differentiation of the floral organs. The protein localisation patterns revealed a few deviations from known mRNA expression patterns, suggesting a non-cell autonomous action of these factors or alternative control mechanisms. In addition, we observed a change in the subcellular localisation of SEPALLATA3 from a predominantly nuclear localisation to a more cytoplasmic localisation, occurring specifically during petal and stamen development. Furthermore, we show that the down-regulation of the homeodomain transcription factor WUSCHEL in ovular tissues is preceded by the occurrence of both AGAMOUS and SEPALLATA3 proteins, supporting the hypothesis that both proteins together suppress WUSCHEL expression in the ovule. Conclusion This approach provides a highly detailed in situ map of MADS domain protein presence during early and later stages of floral development. The subcellular localisation of the transcription factors in the cytoplasm, as observed at certain stages during development, points to mechanisms other than transcriptional control. Together this information is essential to understand the role of these proteins in the regulatory processes that drive floral development and leads to new hypotheses.

Urbanus, Susan L; de Folter, Stefan; Shchennikova, Anna V; Kaufmann, Kerstin; Immink, Richard GH; Angenent, Gerco C

2009-01-01

169

``Agrolistic'' Transformation of Plant Cells: Integration of T-Strands Generated in planta  

Microsoft Academic Search

We describe a novel plant transformation technique, termed ``agrolistic,'' that combines the advantages of the Agrobacterium transformation system with the high efficiency of biolistic DNA delivery. Agrolistic transformation allows integration of the gene of interest without undesired vector sequence. The virulence genes virD1 and virD2 from Agrobacterium tumefaciens that are required in bacteria for excision of T-strands from the tumor-inducing

Genevieve Hansen; Mary-Dell Chilton

1996-01-01

170

In planta quantification of endoreduplication using fluorescent in situ hybridization (FISH).  

PubMed

Endopolyploidy, i.e. amplification of the genome in the absence of mitosis, occurs in many plant species and happens along with organ and cell differentiation. Deciphering the functional roles of endopolyploidy is hampered by the fact that polyploid tissues generally comprise cells with various ploidy levels. In some fleshy fruits (amongst them tomato fruit) the ploidy levels present at the end of development range from 2C to 256C in the same tissue. To investigate the temporal and spatial distribution of endopolyploidy it is necessary to address the DNA content of individual nuclei in situ. Conventional methods such as fluorometry or densitometry can be used for some tissues displaying favorable characteristics, e.g. small cells, small nuclei, organization in a monolayer, but high levels of varying polyploidy are usually associated with large sizes of nuclei and cells, in a complex three dimensional (3-D) organization of the tissues. The conventional methods are inadequate for such tissue, becoming semi-quantitative and imprecise. We report here the development of a new method based on fluorescent in situ bacterial artificial chromosome hybridizations that allows the in situ determination of the DNA ploidy level of individual nuclei. This method relies on the counting of hybridization signals and not on intensity measurements and is expected to provide an alternative method for mapping endopolyploidy patterns in mature, 3-D organized plant tissues as illustrated by the analysis of ploidy level and cell size in pericarp from mature green tomato fruit. PMID:21418357

Bourdon, Matthieu; Coriton, Olivier; Pirrello, Julien; Cheniclet, Catherine; Brown, Spencer C; Poujol, Christel; Chevalier, Christian; Renaudin, Jean-Pierre; Frangne, Nathalie

2011-06-01

171

Origin and evolution of metal P-type ATPases in Plantae (Archaeplastida)  

PubMed Central

Metal ATPases are a subfamily of P-type ATPases involved in the transport of metal cations across biological membranes. They all share an architecture featuring eight transmembrane domains in pairs of two and are found in prokaryotes as well as in a variety of Eukaryotes. In Arabidopsis thaliana, eight metal P-type ATPases have been described, four being specific to copper transport and four displaying a broader metal specificity, including zinc, cadmium, and possibly copper and calcium. So far, few efforts have been devoted to elucidating the origin and evolution of these proteins in Eukaryotes. In this work, we use large-scale phylogenetics to show that metal P-type ATPases form a homogenous group among P-type ATPases and that their specialization into either monovalent (Cu) or divalent (Zn, Cd…) metal transport stems from a gene duplication that took place early in the evolution of Life. Then, we demonstrate that the four subgroups of plant metal ATPases all have a different evolutionary origin and a specific taxonomic distribution, only one tracing back to the cyanobacterial progenitor of the chloroplast. Finally, we examine the subsequent evolution of these proteins in green plants and conclude that the genes thoroughly characterized in model organisms are often the result of lineage-specific gene duplications, which calls for caution when attempting to infer function from sequence similarity alone in non-model organisms.

Hanikenne, Marc; Baurain, Denis

2013-01-01

172

Phylogenetic Relationships of Fungi, Plantae, and Animalia Inferred from Homologous Comparison of Ribosomal Proteins  

Microsoft Academic Search

.   The complete set of available ribosomal proteins was utilized, at both the peptidic and the nucleotidic level, to establish\\u000a that plants and metazoans form two sister clades relative to fungi. Different phylogenetic inference methods are applied to\\u000a the sequence data, using archeans as the outgroup. The evolutionary length of the internal branch within the eukaryotic crown\\u000a trichotomy is demonstrated

Gabriel Bittar

1998-01-01

173

CALIDAD NUTRICIONAL DE LA PLANTA DE SORGO NEGRO FORRAJERO (Sorghum almum) PARA ALIMENTACIÓN ANIMAL 1  

Microsoft Academic Search

Nutritional quality of black sorghum (Sorghum almum) for fodder for animal feeding. The purpose of this study was to determine the phenological development and the nutritional quality of Sorghum almun during different growth stages. The seed was cultivated in the Alfredo Volio Mata Experimental Station of the University of Costa Rica. Eighteen kg of 88% germinal seed per hectare were

Ana Lorena Amador; Carlos Boschini

2000-01-01

174

METODOS RAPIDOS DE ANALISIS DE PLANTAS PARA EVALUAR LA NUTRICION NITROGENADA DEL CULTIVO DE TRIGO  

Microsoft Academic Search

) and four wheat varieties (similar growing cycle). Nitrate concentration in JBT was related to BS and decreased with plant age and increased with the increase in the nitrogen fertilization rate. The effect of variety was of low impact on both, JBT and BS. The determined thresholds of nitrate concentration in the JBT to achieve approximately 90% of maximum yield

RA STRADA; FCA-INTA Balcarce

2000-01-01

175

Screening for inhibitors of chloroplast galactolipid synthesis acting in membrano and in planta.  

PubMed

The knowledge of the membrane lipid metabolism in photosynthetic cells is expected to benefit from the availability of inhibitors acting at the level of specific enzymes like MGD1 (E.C. 2.4.1.46) that catalyzes the synthesis of monogalactosyldiacylglycerol (MGDG) in chloroplasts. MGDG is a major lipid of photosynthetic membrane, interacting with photosystems. It is the precursor of digalactosyldiacylglycerol that serves as a phospholipid surrogate when plants are deprived of phosphate, and it is a source of polyunsaturated fatty acids for jasmonic acid syntheses. MGD1 is activated by phosphatidic acid and thus a coupling point between phospholipid and galactolipid metabolisms. Here we describe a method to screen for inhibitors of MGD1 assayed in liposomes. Selected compounds can therefore reach the core of the biological membranes in which the target sits. We then describe a secondary screen to evaluate the efficiency of developed compounds at the whole plant level. Major issues raised by the screening of inhibitors acting on membrane proteins are discussed and can be useful for similar targets. PMID:24306864

Boudière, Laurence; Maréchal, Eric

2014-01-01

176

Acción biocida de plantas de Piper tuberculatum Jacq. sobre Diatraea saccharalis (Lepidóptera, Pyralidae)  

Microsoft Academic Search

The biocid action of DCM:MeOH (2:1), EtOH and aqueous extracts of leaves, stems and mature spikes (with fruits and seeds) of field plants and DCM:MeOH (2:1) extract of in vitro plants of Piper tuberculatum on III larval stage of Diatraea saccharalis was evaluated. The method was by inoculating the previously eluted extract with distillate water as topic applications on the

Gladys V. Soberón; Consuelo Rojas; Jorge Saavedra; Massuo J. Kato; Guillermo E. Delgado

177

Sexual mating preferences in vitro and in planta among Japanese isolates of Phytophthora infestans  

Microsoft Academic Search

The sexual preferences of Japanese isolates of Phytophthora infestans were determined by mating on agar, in broth, or in plants. The influence of their sexual preference was confirmed in the host tissues. Three wild-type isolates and a ß-glucuronidase (GUS) transformant were co-cultured to identify the origin of antheridia and oogonia. Japanese A1 isolate had a unique sexual preference compared with

Kiyotaka Gotoh; Seishi Akino; Takako Kiyoshi; Shigeo Naito

2005-01-01

178

RT real-time PCR-based quantification of Uromyces fabae in planta.  

PubMed

Quantification of obligate biotrophic parasites has been a long-standing problem in plant pathology. Many attempts have been made to determine how much of a pathogen is present in infected plant tissue. Methods of quantification included scoring disease symptoms, microscopic evaluation, determination of specific compounds like Ergosterol, and lately nucleic acid-based technologies. All of these methods have their drawbacks, and even real-time PCR may not be quantitative if for example the organism of interest has specific and differing numbers of nuclei in different infection structures. We applied reverse transcription (RT) real-time PCR to quantify Uromyces fabae within its host plant Vicia faba. We used three different genes, which have been shown to be constitutively expressed. Our analyses show an exponential increase of fungal material between 4 and 9 days post inoculation and thereafter reaching a steady state of around 45% of total RNA. We also used haustorium-specific genes to determine the amount of haustoria present at each time point. These analyses parallel the development of the whole fungus with the exception of the steady-state level, which is only around 5% of the total RNA. This indicates that RT real-time PCR is a suitable method for quantification of obligate biotrophic parasites, and also for the differentiation of developmental stages. PMID:21707731

Voegele, Ralf T; Schmid, Annette

2011-09-01

179

Sistema Planeta-Satélite. Simulación orbital y potenciales gravitatorios  

NASA Astrophysics Data System (ADS)

Se presenta un programa (desarrollado en Quick Basic 4.5) que simula, en tres dimensiones, el movimiento orbital de un satélite (o luna) alrededor de un planeta, al tiempo que calcula y grafica, en un plano, el potencial gravitatorio del sistema en función de la distancia al planeta. Para la simulación orbital, se emplea la matriz de transformación entre el sistema del planeta y el plano orbital. Para el cálculo y graficación del potencial se aplica un desarrollo en serie hasta el segundo orden, que da cuenta del efecto de achatamiento de los polos, en caso de que éste exista. Las longitudes de los ejes del planeta, la masa de éste y del satélite, sus tamaños aparentes, y los parámetros orbitales son introducidos por el usuario.

Medina, C.; Carrillo, M.

180

MÉXICO. DILEMA ENTRE LA ECONOMÍA Y LA INSEGURIDAD  

Microsoft Academic Search

La poca efectividad en el combate al crimen organizado en México tiene su origen en diversas causas, que van desde la incapacidad de conceptualizarla, hasta la negación del sentido económico sobre el que se soporta la actividad delictiva en nuestro país, lo cual impide hacer propuestas de política más efectivas que no se reduzcan únicamente a los enfrentamientos violentos con

Guillermo Campos Ríos

2012-01-01

181

Tratamento da rinite alérgica: comparação entre acupuntura e corticóide nasal  

Microsoft Academic Search

Objective: This study compared the treatment of allergic rhinithis effect using acupuncture and topic nasal corticoids in the evaluation of the main clinical parameters ( sneezing, itching, rhinorrhea, nasal congestion, and postnasal drainage) either in the otorhinolaryngological examination and in the laboratorial values of blood eosinophil and total IgE serum. Method: A total of 53 patients with perennial allergic rhini-

Cecília Baccili; Cury Megid; Patrícia Maluf Cury; José Antonio Cordeiro; Rassen Saidah; Bosco Guerreiro da Silva

182

GPS, punto de contacto entre la Astronomía y otras disciplinas  

NASA Astrophysics Data System (ADS)

En los primeros años de la pasada década, un grupo de Astrónomos de La Plata iniciaron trabajos de investigación en Geodesia Satelital. En esta presentación se propone repasar sus principales logros y situarlos en el contexto del desarrollo de la disciplina a nivel mundial. Por entonces las aplicaciones prácticas de la disciplina eran indirectas y solo evidentes para los especialistas. Los errores del Posicionamiento Satelital eran de varios metros y en posicionamiento relativo, del orden de medio metro. Estos resultados se lograban al cabo de varios días de medición continuada. En los años siguientes, el sistema GPS alcanzó su nivel operacional y produjo una revolución tanto en lo relacionado con los tiempos de medición como con las precisiones. El grupo de La Plata se desarrolló simultáneamente con GPS, lo que posibilitó su participación actual en diversos temas vigentes: aplicaciones de alta precisión para la materialización de sistemas terrestres de referencia, monitoreo de movimientos de la corteza, contribución con servicios internacionales para la determinación de movimientos tectónicos globales y regionales, monitoreo de la ionósfera a partir de la propagación de las señales, determinación de la ondulación del geoide a escala local, etc. También se generaron muchas aplicaciones prácticas algunas en tiempo real: navegación, apoyo a imágenes aéreas o satelitales, aplicaciones a la agricultura, catastro y ordenamiento territorial, apoyo a relevamientos geofísicos, etc.

Perdomo, R.

183

Regulaciones del mercado laboral: un estudio comparativo entre países  

Microsoft Academic Search

En este trabajo se analizan tres tipos de instituciones prevalecientes en los mercados laborales de muchos países, normas sobre salario mínimo, introducción de costos no salariales (prestaciones complementarias) y las políticas de salario y empleo del gobierno. Se sostiene que estos tres son los aspectos estratégicos a analizar en el caso de los países en desarrollo con respecto a las

Peter R. Fallon; Luis Riveros

184

COOPERACION ENTRE GOBIERNOS PARA LA RECAUDACION DE IMPUESTOS COMPARTIDOS  

Microsoft Academic Search

This paper deals with the problem of fiscal corresponsability of twogovemment levels in a game theory context. It is assumed that Nash equilibriaof the non-cooperative game between both Govemments are not Pareto optimal.Then, assurning the existence of non-equilibrium strategies, which would allowboth of them to improve, it is questioned whether the introduction ofinterposed agents (Tax Agencies) would be a way

Francisco Pérez García; Gonzalo Olcina Vauteren

1991-01-01

185

Hipertensão arterial entre trabalhadores de petróleo expostos a ruído  

Microsoft Academic Search

A cross-sectional study with a retrospective component was conducted to evaluate oc- cupational noise exposure as a potential risk factor for arterial hypertension among 775 workers from an oil-drilling industry. Hypertension was defined as ? 140\\/90mmHg. Occupational noise exposure was measured as: (1) exposure to sound pressure levels ? 85dbA for 10 years or more and (2) moderate-to-severe noise-induced hearing

Norma Suely Souto Souza; Fernando Martins Carvalho; Rita de Cássia Pereira Fernandes

2001-01-01

186

A complexidade das relações entre drogas, álcool e violência  

Microsoft Academic Search

This article discuss the complex relations between drugs and violence. Drawing on empirical studies and current forms of discourse, it analyzes conceptual and methodological problems related to the establishment of causal nexuses, risks, and associations. By demonstrat- ing the theoretical and practical difficulties in such associations, it also points to the need for a debate in the field of public

Maria Cecília de Souza Minayo; Suely Ferreira Deslandes

1998-01-01

187

Comparación entre los sitios de LLAMA y APEX  

NASA Astrophysics Data System (ADS)

A comparison among the meteorological condition prevailing at the location of APEX (Atacama Pathfinder Experiment) telescope and the site selected to deploy LLAMA (Long Latin American Millimeter Array) is carried out. The later is dubbed Alto Chorrillo, and is located 4800 m above sea level and around 16 km eastward from the town of San Antonio de los Cobres (province of Salta). This work is part of a long term monitoring campaign aim at selecting sites for millimeter and submillimeter radioastronomy that is being carried out by the Instituto Argentino de Radioastronomía (IAR) since 2002. FULL TEXT IN SPANISH

Bareilles, F. A.; Morras, R.; Hauscarriaga, F. P.; Guarrera, L.; Arnal, E. M.; Lepine, J. R. D.

188

Mobilidade dos Funcionários públicos Federais: Diferenças Entre os Poderes  

Microsoft Academic Search

Based on a special Rais-Migra tabulation that allows one to trace work trajectories,the present study estimates the total length of service for active federal civil servants,disaggregated by length of time spent at present post. Prior time is also considered,whether spent in other civil service posts or in private employment.This study was largely motivated by the need to estimate the civil

Kaizô Iwakami Beltrão; Sonoe Sugahara; Fernanda Paes Leme Peyneau; João Luis de Oliveira Mendonça

2005-01-01

189

El cáncer entre las minorías con VIH y sida  

Cancer.gov

Cancer and HIV/AIDS has always been “a tale of two diseases,” according to researchers at the NCI. Infection with HIV not only weakens the immune system, leading to AIDS and increasing the risk of opportunistic infections, but also increases the risk of several types of cancer. This Spanish-language Lifelines articles explains how HIV/AIDS affects cancer risk.

190

Estudio comparativo entre medidas de creatividad: TTCT vs. CREA  

Microsoft Academic Search

Title: Comparative study between creativity measures: TTCT versus CREA. Abstract: The general mission of this work is to make a comparative study between two tests of valuation of the creativity. The used total sample is of 96 students, pertaining to a School of Infantile and Primary Education, of the region of the Plateau (municipality of Jumilla) in the Region of

Olivia López Martínez; Juan Navarro Lozano

2008-01-01

191

Stabilisation et redistribution budgétaires entre régions : État centralisé, État fédéral  

Microsoft Academic Search

[eng] Frédéric Zumer. The fiscal aspects of the future EMU lead to lively debates. The purpose of this work is to consider the stabilizing role of a federal budget in the context of a monetary union, and the appropriateness of creating a specific shock-absorber mechanism in Europe. Its purpose would be to permit the member states to cope with transitory,

Frédéric Zumer

1998-01-01

192

Evaluacion entre colegas profesores (Peer Review of Teachers). ERIC Digest.  

ERIC Educational Resources Information Center

This digest in Spanish examines peer review, focusing on how these types of reviews can improve teacher competence. Peer review is often linked to peer assistance, which helps new and veteran teachers improve their knowledge and skills. In peer-review programs, consulting teachers conduct formal evaluations and recommend whether the participating…

Hertling, Elizabeth

193

USO DE DROGAS ENTRE ESTUDIANTES DE MEDICINA, TEGUCIGALPA, HONDURAS  

Microsoft Academic Search

The use of drugs, in Honduras, involves 25% of college students. The most used substances include legal and recreational drugs, such as alcohol. This study aimed to identify the use of drugs and socio-demographic factors in a sample of 260 medical students. Results: Average age of 20 years old, unemployed and religious women, single, with no children. Alcohol was the

Juana Carolina Buchanan; Sandra Cristina Pillon

2008-01-01

194

Comparaison entre calculs de vulnérabilité sismique et propriétés dynamiques mesurées  

Microsoft Academic Search

Large-scale seismic vulnerability assessment methods use simplified formulas and curves, often without providing uncertainties. They are seldom compared to experimental data. Therefore, we recorded ambient vibrations and estimated modal parameters (resonance frequencies, modal shapes and damping) of 60 buildings in Grenoble (France) of various types (masonry and reinforced concrete). The knowledge of resonance frequencies in the linear domain is essential

Clotaire Michel; Philippe Guéguen; Pierre-Yves Bard

195

Mécanismes physiques et modélisation mécanique du frottement entre corps solides  

Microsoft Academic Search

Physical mechanisms and mechanical models of solid friction. First we present the theory of solid friction due to Bowden and Tabor and its extension by the junction growth theory which provides some theoretical support of Coulomb's friction law. After a brief discussion of its experimental validation, we present some theoretical works developed for a validation or an extension of Bowden–Tabor's

Eric Felder

2000-01-01

196

Négociation entre agents au sein de réseaux ad-hoc  

Microsoft Academic Search

In the last years the multi-agent paradigm has emerged as a suitable solution to the challenges of electronic commerce (e-commerce) applications. However, new problems arise in mobile-commerce scenarios, where agents negotiating on behalf of their users are deployed on mobile devices. Negotiation is a time-constraint process and it might be difficult to realize applications in ad-hoc networks. In this paper

Cosmin Carabelea; Michael Berger

2005-01-01

197

No Financial Disincentive for Choosing More Healthful Entr?es on Children's Menus in Full-Service Restaurants  

PubMed Central

Children are eating restaurant foods more than ever before, and price is among the top considerations for food choices. We categorized and enumerated entrées on children’s menus from 75 full-service restaurant chains to compare prices of more healthful and less healthful entrées to test the assumption that more healthful food is more expensive. The mean (standard deviation) price of more healthful entrées ($5.38 [$2.01]) was not significantly different from the price of less healthful entrées ($5.27 [$2.04]). In contrast to research demonstrating that more healthful foods tend to be more expensive in grocery stores, more healthful entrées on children’s menus in restaurants were not more expensive than less healthful entrées.

West, Delia

2013-01-01

198

DETECCIÓN DE UMBRALES DE ÁREA Y DISTANCIA DE AISLAMIENTO PARA LA OCUPACIÓN DE FRAGMENTOS DE SELVA POR MONOS AULLADORES, Alouatta palliata, EN LOS TUXTLAS, MÉXICO Detection of area thresholds and isolation distance for forest fragment occupation by howler monkeys, Alouatta palliata, in Los Tuxtlas, Mexico  

Microsoft Academic Search

Palabras clave: Alouatta palliata, fragmentación, Los Tuxtlas, México, ocupación de fragmentos, umbrales. ABSTRACT. Are there area thresholds and forest fragment isolation distances at which occupancy by howler monkeys decreases significantly? Are these thresholds similar independently of geographic location? To answer these questions we compared howler monkey populations in two landscapes with different degrees of loss and fragmentation in the tropical

S Mandujano; A Estrada

199

Remote sensing of gene expression in Planta: transgenic plants as monitors of exogenous stress perception in extraterrestrial environments.  

PubMed

Transgenic arabidopsis plants containing the alcohol dehydrogenase (Adh) gene promoter fused to the green fluorescent protein (GFP) reporter gene were developed as biological sensors for monitoring physiological responses to unique environments. Plants were monitored in vivo during exposure to hypoxia, high salt, cold, and abcissic acid in experiments designed to characterize the utility and responses of the Adh/GFP biosensors. Plants in the presence of environmental stimuli that induced the Adh promoter responded by expressing GFP, which in turn generated a detectable fluorescent signal. The GFP signal degraded when the inducing stimulus was removed. Digital imaging of the Adh/GFP plants exposed to each of the exogenous stresses demonstrated that the stress-induced gene expression could be followed in real time. The experimental results established the feasibility of using a digital monitoring system for collecting gene expression data in real time from Transgenic Arabidopsis Gene Expression System (TAGES) biosensor plants during space exploration experiments. PMID:11987307

Manak, Michael S; Paul, Anna-Lisa; Sehnke, Paul C; Ferl, Robert J

2002-01-01

200

ENERGÍA SOLAR Y AGRICULTURA EN CUBA. CONCEPCIÓN Y PRUEBAS DE UN SECADOR SOLAR DE PLANTAS MEDICINALES CON CUBIERTA DE POLIETILENO  

Microsoft Academic Search

En el presente trabajo se presenta la concepción, construcción, y pruebas de factibilidad de un secador solar de cubierta de polietileno introducido en una Unidad Básica Económica del MINAGRI , en la provincia de Santiago de Cuba, Cuba. El secador fue evaluado utilizando instrumentos y técnicas de precisión para medir radiación solar y temperaturas del aire, lo que permitió hacer

Ciro César Bergues Ricardo; Pedro Griñàn Villafañe; Jorge Luis Abdala R; Susana Fonseca Fonseca; Alonso Torres Ten

2011-01-01

201

DISTRIBUCIÓN DE PLOMO EN SUELOS CONTAMINADOS EN EL ENTORNO DE UNA PLANTA DE RECICLAJE DE BATERÍAS ÁCIDAS  

Microsoft Academic Search

Total Pb, Cd, Cu, Ni and Zn concentrations and the distribution of lead in soils from a farmland near a battery recycling plant in Madrid (Spain) were investigated to establish a possible relationship with a recent episode of horses death that presented lead intoxication symptoms before dying. Total Pb and Cd levels presented a clear decrease with distance to the

Victoria CALA; Yukihiko KUNIMINE

202

In vivo trans-specific gene silencing in fungal cells by in planta expression of a double-stranded RNA  

PubMed Central

Background Self-complementary RNA transcripts form a double-stranded RNA (dsRNA) that triggers a sequence-specific mRNA degradation, in a process known as RNA interference (RNAi), leading to gene silencing. In vascular plants, RNAi molecules trafficking occur between cells and systemically throughout the plant. RNAi signals can spread systemically throughout a plant, even across graft junctions from transgenic to non-transgenic stocks. There is also a great interest in applying RNAi to pathogenic fungi. Specific inhibition of gene expression by RNAi has been shown to be suitable for a multitude of phytopathogenic filamentous fungi. However, double-stranded (ds)RNA/small interfering (si)RNA silencing effect has not been observed in vivo. Results This study demonstrates for the first time the in vivo interference phenomenon in the pathogenic fungus Fusarium verticillioides, in which expression of an individual fungal transgene was specifically abolished by inoculating mycelial cells in transgenic tobacco plants engineered to express siRNAs from a dsRNA corresponding to the particular transgene. Conclusion The results provide a powerful tool for further studies on molecular plant-microbe and symbiotic interactions. From a biotechnological perspective, silencing of fungal genes by generating siRNAs in the host provides a novel strategy for the development of broad fungi-resistance strategies in plants and other organisms.

2010-01-01

203

In Planta - Complementation of Clavibacter Michiganensis Subsp. sepedonicus Strains Deficient in Cellulase Production or HR Induction Restores Virulence  

Microsoft Academic Search

Clavibacter michiganensis subsp. sepedonicus, a Gram positive bacterium that causes bacterial ring rot of potato, was studied in eggplant, an alternate host, using strains that differed in phenotype. Two factors affecting virulence, the ability to induce a hypersensitive response (HR) and cellulase production, were studied. A plasmid-free isolate of C. michiganensis subsp. sepedonicus that causes HR on tobacco but is

Riitta Nissinen; Shaaban Kassuwi; Riikka Peltola; Mary C. Metzler

2001-01-01

204

Production and characterization of in planta transiently produced polygalacturanase from Aspergillus niger and its fusions with hydrophobin or ELP tags  

PubMed Central

Background Pectinases play an important role in plant cell wall deconstruction and have potential in diverse industries such as food, wine, animal feed, textile, paper, fuel, and others. The demand for such enzymes is increasing exponentially, as are the efforts to improve their production and to implement their use in several industrial processes. The goal of this study was to examine the potential of producing polygalacturonase I from Aspergillus niger in plants and to investigate the effects of subcellular compartmentalization and protein fusions on its accumulation and activity. Results Polygalacturonase I from Aspergillus niger (AnPGI) was transiently produced in Nicotiana benthamiana by targeting it to five different cellular compartments: apoplast, endoplasmic reticulum (ER), vacuole, chloroplast and cytosol. Accumulation levels of 2.5%, 3.0%, and 1.9% of total soluble protein (TSP) were observed in the apoplast, ER, and vacuole, respectively, and specific activity was significantly higher in vacuole-targeted AnPGI compared to the same enzyme targeted to the ER or apoplast. No accumulation was found for AnPGI when targeted to the chloroplast or cytosol. Analysis of AnPGI fused with elastin-like polypeptide (ELP) revealed a significant increase in the protein accumulation level, especially when targeted to the vacuole where the protein doubles its accumulation to 3.6% of TSP, while the hydrophobin (HFBI) fusion impaired AnPGI accumulation and both tags impaired activity, albeit to different extents. The recombinant protein showed activity against polygalacturonic acid with optimum conditions at pH 5.0 and temperature from 30 to 50°C, depending on its fusion. In vivo analysis of reducing sugar content revealed a higher release of reducing sugars in plant tissue expressing recombinant AnPGI compared to wild type N. benthamiana leaves. Conclusion Our results demonstrate that subcellular compartmentalization of enzymes has an impact on both the target protein accumulation and its activity, especially in the case of proteins that undergo post-translational modifications, and should be taken into consideration when protein production strategies are designed. Using plants to produce heterologous enzymes for the degradation of a key component of the plant cell wall could reduce the cost of biomass pretreatment for the production of cellulosic biofuels.

2014-01-01

205

Microcistina en plantas de tratamiento de agua para consumo humano en un ambiente tropical: el Área Metropolitana de Costa Rica  

Microsoft Academic Search

Microcystin in plants that treat water for human consumption in a tropical environment: the Metropolitan Area of Costa Rica. We measured microcystin levels in water of the Metropolitan Area of Costa Rica by competitive inhibition ELISA and we quantified total coliforms, fecal coliforms, Escherichia coli (by a Most Probable Number method) and aerobic count. We wanted to identify any cyanotoxin

Adrián Avendaño Lopez; Carolina Arguedas Villa

206

ADUBAÇÃO COM NPK EM COQUEIRO ANÃO-VERDE (Cocos nucifera L.) - ATRIBUTOS QUÍMICOS DO SOLO E NUTRIÇÃO DA PLANTA1  

Microsoft Academic Search

There are very few information about fertilization of coconut grown in the State of São Paulo, Brazil. So a field experiment with 'Dwarf Green' coconut was carried out to study the effects of NPK rates on some soil chemical properties and plant nutrition, from September, 2000 to February, 2004. The trial was located on an Oxisol in the west part

LUIZ ANTONIO; JUNQUEIRA TEIXEIRA; ONDINO CLEANTE BATAGLIA; SALATIÉR BUZETTI; ENES FURLANI

207

In planta production of the highly potent resveratrol analogue pterostilbene via stilbene synthase and O-methyltransferase co-expression.  

PubMed

Resveratrol and related stilbenes are thought to play important roles in defence responses in several plant species and have also generated considerable interest as nutraceuticals owing to their diverse health-promoting properties. Pterostilbene, a 3,5-dimethylether derivative of resveratrol, possesses properties similar to its parent compound and, additionally, exhibits significantly higher fungicidal activity in vitro and superior pharmacokinetic properties in vivo. Recombinant enzyme studies carried out using a previously characterized O-methyltransferase sequence from Sorghum bicolor (SbOMT3) demonstrated its ability to catalyse the A ring-specific 3,5-bis-O-methylation of resveratrol, yielding pterostilbene. A binary vector was constructed for the constitutive co-expression of SbOMT3 with a stilbene synthase sequence from peanut (AhSTS3) and used for the generation of stably transformed tobacco and Arabidopsis plants, resulting in the accumulation of pterostilbene in both species. A reduced floral pigmentation phenotype observed in multiple tobacco transformants was further investigated by reversed-phase HPLC analysis, revealing substantial decreases in both dihydroquercetin-derived flavonoids and phenylpropanoid-conjugated polyamines in pterostilbene-producing SbOMT3/AhSTS3 events. These results demonstrate the potential utility of this strategy for the generation of pterostilbene-producing crops and also underscore the need for the development of additional approaches for minimizing concomitant reductions in key phenylpropanoid-derived metabolites. PMID:21902799

Rimando, Agnes M; Pan, Zhiqiang; Polashock, James J; Dayan, Franck E; Mizuno, Cassia S; Snook, Maurice E; Liu, Chang-Jun; Baerson, Scott R

2012-04-01

208

Inhibitory effect of Xenorhabdus nematophila TB on plant pathogens Phytophthora capsici and Botrytis cinerea in vitro and in planta  

PubMed Central

Entomopathogenic bacteria Xenorhabdus spp. produce secondary metabolites with potential antimicrobial activity for use in agricultural productions. This study evaluated the inhibitory effect of X. nematophila TB culture on plant pathogens Botrytis cinerea and Phytophthora capsici. The cell-free filtrate of TB culture showed strong inhibitory effects (>90%) on mycelial growth of both pathogens. The methanol-extracted bioactive compounds (methanol extract) of TB culture also had strong inhibitory effects on mycelial growth and spore germinations of both pathogens. The methanol extract (1000??g/mL) and cell-free filtrate both showed strong therapeutic and protective effects (>70%) on grey mold both in detached tomato fruits and plants, and leaf scorch in pepper plants. This study demonstrates X. nematophila TB produces antimicrobial metabolites of strong activity on plant pathogens, with great potential for controlling tomato grey mold and pepper leaf scorch and being used in integrated disease control to reduce chemical application.

Fang, Xiangling; Zhang, Manrang; Tang, Qian; Wang, Yonghong; Zhang, Xing

2014-01-01

209

Plantas asociadas a la pesca y a sus recursos por los Indígenas Chorote del Chaco Semiarido (Argentina)  

Microsoft Academic Search

Summary: Plants associated to fishing and to their resources by Chorote indians from Chaco Semiarido (Argentine). Chorote indians belong to the Mataco-mataguayo linguistic family, they live in Argentina's Semiarid Chaco along the riverbanks of the Pilcomayo river in Salta province. Traditionally, they obtained their own living from hunting, gathering and fishing; being the latter of high cultural and economic value

GUSTAVO F. SCARPA

210

In planta induced changes in the native plasmid profile of Pseudomonas syringae pathover phaseolicola strain 1302A.  

PubMed

Pseudomonas syringae pv. phaseolicola (Pph) strain 1302A, a causative agent of halo blight in the common bean Phaseolus vulgaris, contains four native plasmids designated pAV505 (150 kb), pAV506 (50 kb), pAV507 (47 kb) and pAV508 (42 kb). Pph 1302A also contains a 106 kb genomic island PPHGI-1 which shares features with integrative and conjugative elements (ICElands) and carries the effector gene avrPphB (hopAR1) which triggers a defensive response in bean cultivars carrying the matching R3 resistance gene. It has been shown that when Pph 1302A is sequentially inoculated (passaged) through resistant bean cultivar Tendergreen (TG) in which the hypersensitive response (HR) is generated, the three largest plasmids are lost and an extra ?100 kb plasmid is gained, which tests confirmed to be the 106 kb circular form of PPHGI-1. The aim of the current study was to determine if upon further passaging though bean plants, the plasmid profile of Pph 1302A would alter again and if the missing plasmids had been integrated into the chromosome. Pph 1302A-P6, the strain with the altered plasmid profile was passaged twice through TG and of the four re-isolated strains examined all displayed the plasmid profile associated with wildtype Pph 1302A, that is, all four native plasmids had reappeared and the PPHGI-1 plasmid was absent. This demonstrated that the plasmid composition of Pph 1302A-P6 could indeed change on further exposure to the plant environment and also that the seemingly missing native plasmids were still present within the genome, lending evidence to the theory that they had integrated into the chromosome. Furthermore two of these re-isolated strains had lost PPHGI-1 entirely, meaning they no longer triggered a HR on TG and instead generated a disease response. This study clearly demonstrates the plasticity of the bacterial genome and the extent it can be influenced by the plant environment and conditions generated during the HR. PMID:23895800

Neale, Helen C; Slater, Ross T; Mayne, Lisa-Marie; Manoharan, Bharani; Arnold, Dawn L

2013-11-01

211

Más Conceptos Erróneos a Evitar en la Enseñanza sobre las Plantas  

NSDL National Science Digital Library

The resource is useful for teacher's professional development by alerting educators to many plant misconceptions in teaching literature. In the thought provoking, peer reviewed resource fifty misconceptions are identified. Some misconceptions are easier to identify because they are oversimplifications, overgeneralizations, or misidentifications. Others are more difficult to identify because they are obsolete concepts and terms or flawed research.

David Hershey (biology education consultant;)

2006-04-01

212

A visual identification key utilizing both gestalt and analytic approaches to identification of Carices present in North America (Plantae, Cyperaceae)  

PubMed Central

Abstract Images are a critical part of the identification process because they enable direct, immediate and relatively unmediated comparisons between a specimen being identified and one or more reference specimens. The Carices Interactive Visual Identification Key (CIVIK) is a novel tool for identification of North American Carex species, the largest vascular plant genus in North America, and two less numerous closely-related genera, Cymophyllus and Kobresia. CIVIK incorporates 1288 high-resolution tiled image sets that allow users to zoom in to view minute structures that are crucial at times for identification in these genera. Morphological data are derived from the earlier Carex Interactive Identification Key (CIIK) which in turn used data from the Flora of North America treatments. In this new iteration, images can be viewed in a grid or histogram format, allowing multiple representations of data. In both formats the images are fully zoomable.

2013-01-01

213

Antibiosis and Antagonism of Sclerotinia homoeocarpa and Drechslera poae by Pseudomonas fluorescens Pf-5 In Vitro and In Planta.  

PubMed

ABSTRACT Pseudomonas fluorescens strain Pf-5, which produces several antifun-gal metabolites, including the antibiotics pyoluteorin, pyrrolnitrin, and 2,4-diacetylphloroglucinol, was tested for its ability to inhibit Sclerotinia homoeocarpa (causal agent of dollar spot) and Drechslerapoae (causal agent of 'melting-out') in vitro and in turfgrass; Tn5 mutants with altered antibiotic production also were tested. Inhibition in vitro differed with the medium used, but both fungi generally were inhibited by Pf-5. In most cases, a mutant deficient in pyoluteorin but not pyrrolnitrin or 2,4-di-acetylphloroglucinol was as inhibitory as Pf-5, whereas a pyrrolnitrin-deficient mutant was less inhibitory than Pf-5 in most fungus/medium combinations. High-performance liquid chromatography analysis of culture extracts showed that bacterial genotype and nutrition have an interactive effect on antibiotic production, such that conditions causing an increase in one antibiotic may increase or decrease another. The purported deficiencies for the pyrrolnitrin- and pyoluteorin-deficient mutants were confirmed. In S. homoeocarpa-infested grass clippings incubated in a moist chamber, Pf-5 reduced mycelial growth, whereas the pyrrolnitrin-deficient mutant did not and the pyoluteorin-deficient mutant was intermediate. In greenhouse experiments, Pf-5 reduced dollar spot disease incidence in bentgrass and bluegrass when sprayed over inoculated turf. In grass clippings infested with D. poae and incubated in a moist chamber under favorable conditions for spore production, Pf-5 did not reduce significantly the number of spores produced compared with the non-treated control. However, Pf-5 reduced melting-out disease incidence and severity in bluegrass inoculated with spores of D. poae under greenhouse conditions. PMID:18945079

Rodriguez, F; Pfender, W F

1997-06-01

214

Production of recombinant single chain antibodies (scFv) in vegetatively reproductive Kalanchoe pinnata by in planta transformation.  

PubMed

We developed an asexual reproductive plant, Kalanchoe pinnata, as a new bioreactor for plant-based molecular farming using a newly developed transformation method. Leaf crenate margins were pin-pricked to infect the plant with the Agrobacterium strain LBA4404 and vacuum infiltration was also applied to introduce the target gene into the plants. Subsequently, the young mother leaf produced new clones at the leaf crenate margins without the need for time- and labor-consuming tissue culture procedures. The average transformation rates were approximately 77 and 84% for pin-prickling and vacuum-infiltration methods, respectively. To functionally characterize an introduced target protein, a nucleic acid hydrolyzing recombinant 3D8 scFv was selected and the plant based 3D8 scFv proteins were purified and analyzed. Based on abzyme analysis, the purified protein expressed with this system had catalytic activity and exhibited all of properties of the protein produced in an E. coli system. This result suggested that vegetatively reproductive K. pinnata can be a novel and potent bioreactor for bio-pharmaceutical proteins. PMID:19688214

Jung, Yuchul; Rhee, Yong; Auh, Chung-Kyoon; Shim, Hyekyung; Choi, Jung-Jin; Kwon, Suk-Tae; Yang, Joo-Sung; Kim, Donggiun; Kwon, Myung-Hee; Kim, Yong-Sung; Lee, Sukchan

2009-10-01

215

Modeling, identification, and validation of models for predictive ammonia control in a wastewater treatment plant--a case study.  

PubMed

The aim of this work is to develop the ammonia models that could be used for model predictive control (MPC) of nitrification process in a wastewater treatment plant. First, a reduced nonlinear model is presented, which is based on expression for nitrification reaction rate in activated sludge model No. 1 and modified for attached biomass processes, while second, a linear black-box model is shown. The data used for model identification were collected during several weeks of experiments on a real plant so that good identification data were obtained. The designed models were validated based on open loop simulations and predictions. Validation results show that the reduced nonlinear model performs better compared to the linear model, however, both models show relatively large errors compared to the real plant data. Hence, a closed loop simulation study was performed to see the differences between the performance of model predictive controller using previously estimated linear and nonlinear models and a standard proportional integral (PI) controller. From the simulation study results it was seen that in spite of relatively large model errors the MPC algorithms give better results in terms of ammonia removal compared to the PI controller, while MPC with the nonlinear model shows additional improvements over the MPC with the linear model. PMID:16649563

Stare, Aljaz; Hvala, Nadja; Vrecko, Darko

2006-04-01

216

Plantas con Flores: Claves para la Evolución de la Tierra y Para el Bienestar Humano  

NSDL National Science Digital Library

The issue-focused interview discusses how angiosperms, or flowering plants, are important because they hold clues to the evolutionary history of our planet, provide sources of food, medicine, and shelter to humans, and serve as food and habitat for many other organisms.

Pamela Soltis (University of Florida, Gainesville;)

2006-03-01

217

A robust and sensitive synthetic sensor to monitor the transcriptional output of the cytokinin signaling network in planta.  

PubMed

Cytokinins are classic plant hormones that orchestrate plant growth, development, and physiology. They affect gene expression in target cells by activating a multistep phosphorelay network. Type-B response regulators, acting as transcriptional activators, mediate the final step in the signaling cascade. Previously, we have introduced a synthetic reporter, Two Component signaling Sensor (TCS)::green fluorescent protein (GFP), which reflects the transcriptional activity of type-B response regulators. TCS::GFP was instrumental in uncovering roles of cytokinin and deepening our understanding of existing functions. However, TCS-mediated expression of reporters is weak in some developmental contexts where cytokinin signaling has a documented role, such as in the shoot apical meristem or in the vasculature of Arabidopsis (Arabidopsis thaliana). We also observed that GFP expression becomes rapidly silenced in TCS::GFP transgenic plants. Here, we present an improved version of the reporter, TCS new (TCSn), which, compared with TCS, is more sensitive to phosphorelay signaling in Arabidopsis and maize (Zea mays) cellular assays while retaining its specificity. Transgenic Arabidopsis TCSn::GFP plants exhibit strong and dynamic GFP expression patterns consistent with known cytokinin functions. In addition, GFP expression has been stable over generations, allowing for crosses with different genetic backgrounds. Thus, TCSn represents a significant improvement to report the transcriptional output profile of phosphorelay signaling networks in Arabidopsis, maize, and likely other plants that display common response regulator DNA-binding specificities. PMID:23355633

Zürcher, Evelyne; Tavor-Deslex, Deborah; Lituiev, Dmytro; Enkerli, Katalin; Tarr, Paul T; Müller, Bruno

2013-03-01

218

Overexpression of the rice carotenoid cleavage dioxygenase 1 gene in Golden Rice endosperm suggests apocarotenoids as substrates in planta  

Microsoft Academic Search

Carotenoids are converted by carotenoid cleavage dioxygenases that catalyze oxidative cleavage reactions leading to apocarotenoids.\\u000a However, apocarotenoids can also be further truncated by some members of this enzyme family. The plant carotenoid cleavage\\u000a dioxygenase 1 (CCD1) subfamily is known to degrade both carotenoids and apocarotenoids in vitro, leading to different volatile\\u000a compounds. In this study, we investigated the impact of

Andrea Ilg; Qiuju Yu; Patrick Schaub; Peter Beyer; Salim Al-Babili

2010-01-01

219

In planta imaging of ?9-tetrahydrocannabinolic acid in Cannabis sativa L. with hyperspectral coherent anti-Stokes Raman scattering microscopy  

NASA Astrophysics Data System (ADS)

Nature has developed many pathways to produce medicinal products of extraordinary potency and specificity with significantly higher efficiencies than current synthetic methods can achieve. Identification of these mechanisms and their precise locations within plants could substantially increase the yield of a number of natural pharmaceutics. We report label-free imaging of ?9-tetrahydrocannabinolic acid (THCa) in Cannabis sativa L. using coherent anti-Stokes Raman scattering microscopy. In line with previous observations we find high concentrations of THCa in pistillate flowering bodies and relatively low amounts within flowering bracts. Surprisingly, we find differences in the local morphologies of the THCa-containing bodies: organelles within bracts are large, diffuse, and spheroidal, whereas in pistillate flowers they are generally compact, dense, and have heterogeneous structures. We have also identified two distinct vibrational signatures associated with THCa, both in pure crystalline form and within Cannabis plants; at present the exact natures of these spectra remain an open question.

Garbacik, Erik T.; Korai, Roza P.; Frater, Eric H.; Korterik, Jeroen P.; Otto, Cees; Offerhaus, Herman L.

2013-04-01

220

In planta imaging of ??-tetrahydrocannabinolic acid in Cannabis sativa L. with hyperspectral coherent anti-Stokes Raman scattering microscopy.  

PubMed

Nature has developed many pathways to produce medicinal products of extraordinary potency and specificity with significantly higher efficiencies than current synthetic methods can achieve. Identification of these mechanisms and their precise locations within plants could substantially increase the yield of a number of natural pharmaceutics. We report label-free imaging of ??-tetrahydrocannabinolic acid (THCa) in Cannabis sativa L. using coherent anti-Stokes Raman scattering microscopy. In line with previous observations we find high concentrations of THCa in pistillate flowering bodies and relatively low amounts within flowering bracts. Surprisingly, we find differences in the local morphologies of the THCa-containing bodies: organelles within bracts are large, diffuse, and spheroidal, whereas in pistillate flowers they are generally compact, dense, and have heterogeneous structures. We have also identified two distinct vibrational signatures associated with THCa, both in pure crystalline form and within Cannabis plants; at present the exact natures of these spectra remain an open question. PMID:23588807

Garbacik, Erik T; Korai, Roza P; Frater, Eric H; Korterik, Jeroen P; Otto, Cees; Offerhaus, Herman L

2013-04-01

221

A Gateway Cloning Vector Set for High-Throughput Functional Analysis of Genes in Planta[w  

PubMed Central

The current challenge, now that two plant genomes have been sequenced, is to assign a function to the increasing number of predicted genes. In Arabidopsis, approximately 55% of genes can be assigned a putative function, however, less than 8% of these have been assigned a function by direct experimental evidence. To identify these functions, many genes will have to undergo comprehensive analyses, which will include the production of chimeric transgenes for constitutive or inducible ectopic expression, for antisense or dominant negative expression, for subcellular localization studies, for promoter analysis, and for gene complementation studies. The production of such transgenes is often hampered by laborious conventional cloning technology that relies on restriction digestion and ligation. With the aim of providing tools for high throughput gene analysis, we have produced a Gateway-compatible Agrobacterium sp. binary vector system that facilitates fast and reliable DNA cloning. This collection of vectors is freely available, for noncommercial purposes, and can be used for the ectopic expression of genes either constitutively or inducibly. The vectors can be used for the expression of protein fusions to the Aequorea victoria green fluorescent protein and to the ?-glucuronidase protein so that the subcellular localization of a protein can be identified. They can also be used to generate promoter-reporter constructs and to facilitate efficient cloning of genomic DNA fragments for complementation experiments. All vectors were derived from pCambia T-DNA cloning vectors, with the exception of a chemically inducible vector, for Agrobacterium sp.-mediated transformation of a wide range of plant species.

Curtis, Mark D.; Grossniklaus, Ueli

2003-01-01

222

Identification and in planta detection of Pseudomonas syringae pv. tomato using PCR amplification of hrpZ Pst  

Microsoft Academic Search

A rapid detection method based on PCR amplification of Pseudomonas syringae pv. tomato chromosomal sequences was developed. Primer design was based on the P. syringae DC3000 hrpZPst gene, which maps on a pathogenicity-associated operon of the hrp\\/hrc pathogenicity island.A 532 bp product corresponding to an internal fragment of hrpZPst was amplified from 50 isolates of P. syringae pv. tomato belonging

Massimo Zaccardelli; Annalisa Spasiano; Carlo Bazzi; Massimo Merighi

2005-01-01

223

In planta production of the highly potent resveratrol analogue pterostilbene via stilbene synthase and O-methyltransferase co-expression  

SciTech Connect

Resveratrol and related stilbenes are thought to play important roles in defence responses in several plant species and have also generated considerable interest as nutraceuticals owing to their diverse health-promoting properties. Pterostilbene, a 3,5-dimethylether derivative of resveratrol, possesses properties similar to its parent compound and, additionally, exhibits significantly higher fungicidal activity in vitro and superior pharmacokinetic properties in vivo. Recombinant enzyme studies carried out using a previously characterized O-methyltransferase sequence from Sorghum bicolor (SbOMT3) demonstrated its ability to catalyse the A ring-specific 3,5-bis-O-methylation of resveratrol, yielding pterostilbene. A binary vector was constructed for the constitutive co-expression of SbOMT3 with a stilbene synthase sequence from peanut (AhSTS3) and used for the generation of stably transformed tobacco and Arabidopsis plants, resulting in the accumulation of pterostilbene in both species. A reduced floral pigmentation phenotype observed in multiple tobacco transformants was further investigated by reversed-phase HPLC analysis, revealing substantial decreases in both dihydroquercetin-derived flavonoids and phenylpropanoid-conjugated polyamines in pterostilbene-producing SbOMT3/AhSTS3 events. These results demonstrate the potential utility of this strategy for the generation of pterostilbene-producing crops and also underscore the need for the development of additional approaches for minimizing concomitant reductions in key phenylpropanoid-derived metabolites.

Rimando A. M.; Liu C.; Pan, Z.; Polashock, J. J.; Dayan, F. E., Mizuno, C. S.; Snook, M. E.; Baerson, S. R.

2012-04-01

224

Courtship behavior of different wild strains of Ceratitis Capitata (Diptera: Tephritidae)  

SciTech Connect

This study documents differences in the courtship behavior of wild strains of Ceratitis capitata (Wiedemann) from Madeira (Portugal), Hawaii (U.S.A.), Costa Rica, and Patagonia (Argentina). Some traits showed large variations and others substantial overlaps. The angle at which the male faced toward the female at the moment of transition from continuous wing vibration and intermittent buzzing changed very little during the course of courtship in all strains, but males from Madeira tended to face more directly toward the female than other males. Females tended to look more, and more directly, toward the males as courtship progressed in all strains. The distance between male and female tended to decrease as courtship proceeded in all strains, but the distances at which males initiated continuous vibration, intermittent buzzing, and jumped onto the female were relatively less variable between strains, except for the strain from Costa Rica. Flies of Madeira courted for longer and the male moved his head and buzzed his wings longer than the other strains. (author) [Spanish] Este estudio documenta diferencias en el comportamiento de cortejo de cepas silvestres de Ceratitis capitata (Wied.) provenientes de Madeira (Portugal), Hawaii (Estados Unidos de Norte America), Costa Rica y Patagonia (Argentina). Algunas caracteristicas mostraron grandes variaciones y traslape substancial. Los angulos a los cuales los machos miraron hacia las hembras cambiaron muy poco en el momento de la transicion de la vibracion continua al zumbido intermitente durante el curso del cortejo en todo las cepas, pero los machos de Madeira tendieron a enfrentar mas directamente a la hembra que otros machos. Los angulos de las hembras disminuyeron claramente durante el cortejo en todas las cepas. La distancia entre el macho y la hembra tendio a disminuir conforme el cortejo continuaba en todas las cepas, pero las distancias a las cuales los machos iniciaron la vibracion continua, el zumbido intermitente, y el salto sobre la hembra eran relativamente menos variables entre cepas excepto la cepa de Costa Rica. Moscas de Madeira cortejaron mas tiempo y el macho moviosu cabeza y zumbaba sus alas mas prolongadamente que las otras cepas. (author)

Briceno, D. [Escuela de Biologia, Universidad de Costa Rica, Ciudad Universitaria (Costa Rica); Eberhard, W. [Escuela de Biologia, Universidad de Costa Rica, Ciudad Universitaria and Smithsonian Tropical Research Institute (Costa Rica); Vilardi, J. [Dpto. de Ciencias Biologicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Cayol, J.-P. [Technical Cooperation Division, IAEA, Wagramerstrasse 5, P.O. Box 100 A-1400, Vienna (Austria); Shelly, T. [A. C. , D. , E. USDA/APHIS/CPHST, 41-650 Ahiki St. Waimanalo, HI 96795 (United States)

2007-03-15

225

Prediction uncertainty of plume characteristics derived from a small number of measuring points  

NASA Astrophysics Data System (ADS)

A small number of measuring points may inflict a bias on the characterisation of flow and transport based on field experiments in the unsaturated zone. Simulation of pure advective transport of a Gaussian plume through a setup of 30 regularly placed measuring points revealed regular temporal fluctuations about the real spatial moments. An irregular setup predicted both irregular fluctuations and larger discrepancies from the real value. From these considerations, a regular setup is recommended. Spatial moments were sensitive to the plume size relative to the distance between individual measuring points. To reduce prediction errors of the variance, the distance between the measuring points should be less than twice the standard deviation of the examined plume. The total size of the setup should cover several standard deviations of the plume to avoid mass being lost from the monitored area. Numerical simulations of a dispersing plume (comparing calculations based on 9000 nodes with 30 measuring points) revealed that vertical and horizontal centres of mass were predicted well at all degrees of heterogeneity, and the same was the case for horizontal variances. Vertical variances were more susceptible to prediction errors, but estimates were of the same order of magnitude as the real values. Résumé Lorsque l'on cherche à caractériser l'écoulement et le transport à partir d'expériences de terrain dans la zone saturée, il arrive qu'un petit nombre de points introduisent un biais. La simulation d'un transport purement advectif d'un panache gaussien au travers d'un ensemble de 30 points de mesures espacés régulièrement fait apparaître des variations temporelles régulières autour des moments spatiaux réels. Un ensemble irrégulier conduit à prédire à la fois des variations irrégulières et de plus grandes divergences par rapport à la valeur réelle. A partir de ces constations, un ensemble régulier est recommandé. Les moments spatiaux sont apparus sensibles à la dimension du panache en fonction de la distance entre les différents points de mesure. Afin de réduire les erreurs de prédiction de la variance, la distance entre les points de mesure doit être inférieure au double de l'écart-type du panache examiné. La dimension totale de l'ensemble doit couvrir une étendue de plusieurs écarts-types du panache pour éviter qu'une partie de la matière échappe à la zone surveillée. Des simulations numériques du panache en dispersion (les calculs de comparaison sont basés sur 9000 nœuds avec 30 points de mesure) montrent que le centre vertical et le centre horizontal de la matière dispersée ont été bien prédits à tous les degrés d'hétérogénéité, de même que pour les variances horizontales. Les variances verticales ont été plus sensibles aux erreurs de prédiction, mais les estimations étaient du même ordre de grandeur que les valeurs réelles. Resumen Un número pequeño de puntos de medida puede producir un sesgo en la caracterización en campo del flujo y transporte de solutos en la zona no saturada. La simulación de transporte advectivo (no difusivo) de un penacho Gaussiano a travs de un conjunto de 30 puntos de medida regularmente distribuidos revelan fluctuaciones temporales regulares de los momentos espaciales del penacho. Una distribución irregular de puntos de medida predijo a su vez fluctuaciones irregulares, más alejadas de la realidad, por lo que se recomienda el uso de esquemas de muestreo regulares. Los momentos espaciales fueron sensibles a la relación entre tamaño del penacho y distancia entre puntos de medida. Para reducir los errores en la predicción de la varianza, la distancia entre puntos de observación debe ser menor que dos veces la desviación estándar del penacho. El tamaño del área muestreada debe cubrir varias desviaciones estándar del penacho para evitar perder parte de la masa. Las simulaciones numricas en un penacho dispersivo, comparando los cálculos basados en 9000 nudos con las 30 medidas, mostraron que las posiciones de los centros de masa y

French, H. K.; van der Zee, S. E. A. T. M.; Leijnse, A.

226

Movimientos peculiares de galaxias en el Universo cercano  

NASA Astrophysics Data System (ADS)

Se presenta un resumen de los resultados más importantes obtenidos en los últimos años sobre movimientos peculiares en el Universo Cercano. En el escenario de inestabilidad gravitacional, el campo de velocidades peculiares es una herramienta muy útil para estimar las fluctuaciones en la distribución de masa que generan los movimientos observados. Esta aproximación puede, además, ser utilizada para poner restricciones al espectro de potencia de la masa, a la relación entre las distribuciones de galaxias y de materia y al valor del parámetro de densidad cosmológico, ?, a grandes escalas. Son además presentados una reconstrucción preliminar de los campos de densidad de masa y velocidades peculiares en el universo cercano usando nuevas medidas de distancias obtenidas con la relación Dn - ?, para una muestra de galaxias elípticas y lenticulares. Dos subestructuras prominentes son encontradas en la región del Gran Atractor, que corresponden a los complejos de Centaurus y Pavo--Indus. Estos últimos, junto a los complejos de Perseus--Piscis y Cetus parecen ser importantes estructuras que determinan el flujo global. El patrón obtenido a través de una muestra de galaxias elípticas muestra variaciones con respecto al obtenido por galaxias espirales. Estos nuevos resultados muestran una coherencia menor en el flujo global, cuando son comparados con resultados obtenidos anteriormente.

Alonso, M. V.

227

Sobre el estado evolutivo de ? Pictoris  

NASA Astrophysics Data System (ADS)

Desde el descubrimiento de fuertes excesos infrarrojos en ? Pictoris, esta estrella ha sido muy estudiada y es considerada candidata a poseer un sistema planetario propio. ? Pic está rodeada de un disco asimétrico de polvo que se observa de canto y que esta vacío a distancias <= 40 AU. Esto se considera una fuerte evidencia en favor de la presencia de (al menos) un planeta gigante. Recientemente se han observado líneas de material circunestelar que se han interpretado como consecuencia de la caída de objetos cometarios sobre esta estrella. Recientemente se ha utilizado la existencia del disco de polvo para atribuir una edad corta (pre - secuencia principal) a ?Pic. Sin embargo, la evaporación de estos cometas provee suficiente polvo como para explicar la presencia del disco observado sin necesidad de edades cortas. En este trabajo mostramos que la comparación entre la tasa de impactos cometarios estimada en el Sistema Solar para diferentes etapas de su evolución y los datos observados en ? Pic indica edades avanzadas para ? Pic. Esta estimación debe tomarse con cautela ya que depende de la estructura de los sistemas planetarios. Además mostramos que, desde el punto de vista de la evolución estelar y con las incertezas presentes en la luminosidad y la temperatura efectiva, existe un continuo de edades posible para ? Pic. Sin embargo, empleando los datos provenientes de los flujos cometarios encontramos que una edad prolongada es consistente con ambos tratamientos.

Brunini, A.; Benvenuto, O. G.

228

Velocidades radiales en Collinder 121  

NASA Astrophysics Data System (ADS)

Se han llevado a cabo observaciones espectroscópicas de unas treinta estrellas que son posibles miembros del cúmulo abierto Collinder 121. Las mismas fueron realizadas con el telescopio de 2.15m del Complejo Astronómico El Leoncito (CASLEO). El análisis de las velocidades radiales derivadas del material obtenido, confirma la realidad de Collinder 121, al menos desde el punto de vista cinemático. La velocidad radial baricentral (LSR) del cúmulo es de +17 ± 3 km.s-1. Esta velocidad coincide, dentro de los errores, con la velocidad radial (LSR) de la nebulosa anillo S308, la cual es de ~20 ± 10 km.s-1. Como S308 se encuentra físicamente asociada a la estrella Wolf-Rayet HD~50896, es muy probable que esta última sea un miembro de Collinder 121. Desde un punto de vista cinemático, la supergigante roja HD~50877 (K3Iab) también pertenecería a Collinder 121. Basándonos en la pertenencia de HD~50896 a Collinder 121, y en la interacción encontrada entre el viento de esta estrella y el medio interestelar circundante a la misma, se estima para este cúmulo una distancia del orden de 1 kpc.

Arnal, M.; Morrell, N.

229

Trabajo remunerado, trabajo doméstico y salud: las diferencias cualitativas y cuantitativas entre mujeres y varones  

Microsoft Academic Search

This article presents the relationship between wage labor, housewifery, and health from a gender perspective. The relationship between the two types of work determines the char- acteristics and meaning of daily life. The methodology combined quantitative and qualitative techniques. An individual questionnaire was applied to 256 male and 121 female workers (n = 377) in a modern pharmaceutical factory in

Adriana Cecilia Cruz; Mariano Noriega

2003-01-01

230

Relación entre turismo, género y sexo. El caso de Buzios - Brasil  

Microsoft Academic Search

The relationship between sex and tourism has followed different paths starting from the Gay \\/ Lesbian friendly market to nudist tourism or prostitution. Not withstanding, there are sill few initiatives to stop this kind of tourism that brings with its huge social problems and scandalizes the public opinion. This is probably due to the fact that from an historic point

Juana A. Norrild

2007-01-01

231

Stress e qualidade de vida em Magistrados da Justiça do Trabalho: diferenças entre homens e mulheres  

Microsoft Academic Search

Occupational stress is a frequent theme at present. Occupational stress in Brazilian judges in charge of labor -related cases, quality of life, work-related stressors and coping strategies were investigated. Seventy-five judges answered five instruments sent to them through the class association. They rated the perceived occupational stress level as 8 on a rating scale of 0 to 10. It was

Marilda E. Novaes Lipp; M. Sacramento Tanganelli

2002-01-01

232

Cultura médica e decisões reprodutivas entre mulheres infectadas pelo vírus da Aids  

Microsoft Academic Search

HIV+ pregnant women face a range of medical information, prescriptions and practices that transform this period into a unique situation relative to previous pregnancies and experiences. This article tries to show which are the factors that affect HIV+ pregnant women's reproductive choices, especially as regards type of delivery and the decision on feminine sterilization adopted, as well as their implications.

Daniela Riva Knauth; Regina Maria Barbosa; Kristine Hopkins; Marion Pegorario; Regina Fachini

2002-01-01

233

Atividade anti-retroviral e propriedades farmacocinéticas da associação entre lamivudina e zidovudina  

Microsoft Academic Search

A lamivudina (3TC) e a zidovudina (ZDV) são agentes anti- retrovirais indicados para o tratamento de infecção pelo HIV. Eles são análogos nucleosídeos, que passam por reações intracelulares de fosforilação e atuam inibindo a enzima transcriptase reversa. Os compostos trifosforilados formados se ligam à cadeia de DNA pró-viral impedindo sua replicação. A terapêutica anti-retroviral utilizando apenas um fármaco ocasiona, freqüentemente,

Jacqueline de Souza; Sílvia Storpirtis

2004-01-01

234

Análise comparativa do isolamento do ruído aéreo entre diferentes painéis de vedação utilizados no Brasil  

Microsoft Academic Search

RESUMO: O artigo aborda a avaliação do isolamento acústico de painéis de vedação que vem sendo utilizados no Brasil. Os painéis que surgem como alternativa à alvenaria convencional e o seu uso indiscrimado, sem uma avaliação dos requisitos mínimos de desempenho, são o principal objetivo deste trabalho. A análise dos resultados do índice de isolação sonora é feita através do

Danielly Borges

235

New York: Les ecoles entre SURR et STAR (New York: Schools between SURR and STAR).  

ERIC Educational Resources Information Center

Three problems of New York City (New York) schools--overpopulation, low academic standards, violence--are examined, and an effort led by parent and teacher organizations to improve conditions is described. Threatened closings (schools under registration review, SURR) and a program of violence reduction (Straight Talk about Risks, STAR) are noted.…

Ueberschlag, Roger

1994-01-01

236

Entre Nous: A Tutorial Approach to the Teaching of Business French.  

ERIC Educational Resources Information Center

Suffolk University (Massachusetts) has developed a degree program in international marketing in French and Spanish that links curricula in the economics department and the department of humanities and modern languages. Language tutorials are mandatory for students in the international economics major. The tutorials are taught by native French- and…

Chaisson, Arthur P.

237

Sur la zone de contact entre une plaque élastique et un obstacle rigide  

NASA Astrophysics Data System (ADS)

This Note deals with the contact problem between an elastic plate and a rigid obstacle ?. The plate is clamped at its edges and submitted to vertical forces f?L(?). The obstacle problem consists in finding the shape of the plate u and the contact set I(f) between the plate and the obstacle. In a first step, we give a result, which we extend to the case of plates, a theorem established by D. Kinderlehrer and G. Stampacchia dealing with the smoothness of the contact set in the case of a two-dimensional membrane. In a second step, we give a stability theorem which links the changes of the external forces to the changes of the contact set. To cite this article: A. Léger, C. Pozzolini, C. R. Mecanique 335 (2007).

Léger, Alain; Pozzolini, Cédric

2007-03-01

238

La reforma de la contratación en el mercado de trabajo: entre la flexibilidad y la seguridad  

Microsoft Academic Search

El actual debate sobre la reforma laboral pendiente en España se centra demasiado en el abaratamiento del despido o las modalidades de contratación como únicas formas de flexibilizar el mercado de trabajo. Este tipo de propuestas, además, choca con la percepción de una fuerte pérdida de seguridad de los trabajadores. En este trabajo nos planteamos cómo conciliar una mayor flexibilidad

Vicente Royuela; Manuel Sanchis

2010-01-01

239

Récentes adipokines : un lien entre l’obésité et l’athérosclérose  

Microsoft Academic Search

Today, cardiovascular diseases (CVD) remain the principal cause of death in industrialized countries and are linked to obesity and metabolic syndrome. Metabolic syndrome is characterized by changes in arterial blood pressure, glucose metabolism, lipid and lipoprotein profiles in addition to inflammation. Adipose tissue produces many cytokines and secretory factors termed adipokines. Intra-abdominal (visceral) adipose tissue in particular, rather than peripheral,

D. Gauvreau; N. Villeneuve; Y. Deshaies; K. Cianflone

2011-01-01

240

Les usages des sciences économiques en Russie entre les années 1960 et 1990  

Microsoft Academic Search

[eng] Abstract Analysis of the development of Russian (Soviet) economics over the last thirty years shows a series of successive changes in the relations between macroeconomics and microeconomics, and among the subfields of political economics, mathematical economics, and global economics. During this period, economists' relations with government took varied forms, from those who sought autonomy to others who voluntarily and

Natalia Chmatko

2002-01-01

241

Comprendre le dialogue: l’interaction entre les micro-organismes et l’hôte  

Microsoft Academic Search

RésuméLe tube digestif des mammifères est beaucoup plus complexe qu’on ne le pensait précédemment. Une couche unique de cellules épithéliales recouvre la totalité des voies digestives, représentant ainsi l’interface la plus étendue avec l’environnement. L’épithélium digestif est un capteur de l’environnement intraluminal et contrôle non seulement les fonctions digestives, absorptives et sécrétoires, mais de plus transmet des informations aux systèmes

Alessio Fasano

2009-01-01

242

Consumo de drogas entre adolescentes: resultados de la Encuesta Nacional de Adicciones, 1998  

Microsoft Academic Search

Objective. The aim of this paper is to describe drug and associated factors use among adolescents (12 to 17 years of age). Material and Methods. Data come from the re- cent Encuesta Nacional de Adicciones, 1998 (National Sur- vey on Addictions) undertaken in urban areas of Mexico. A probabilistic, multi-stage, stratified cluster sampling design was used to select the study

Ma Elena Medina-Mora; Patricia Cravioto; Jorge Villatoro; Clara Fleiz; Fernando Galván-Castillo; Roberto Tapia-Conyer

2003-01-01

243

OPORTUNIDADES DE EXPOSICIÓN AL USO DE DROGAS ENTRE ESTUDIANTES DE SECUNDARIA DE LA CIUDAD DE MÉXICO  

Microsoft Academic Search

SUMMARY Introduction. Our research took place following a prior work developed by James C. Anthony's research group, over the past ten years. In this group's research, the concept of exposure to opportunities to use drugs has been deemed as a useful element to understand the earliest stages of drug involvement, as well as the transition from using one drug such

Fernando A. Wagner; Catalina González-Forteza; Luciana E. Ramos-Lira; James C. Anthony

2003-01-01

244

Descubrimiento de precios entre mercados de opciones y contado. El caso del Ibex35  

Microsoft Academic Search

This study investigates the lead-lag relationships between option and index markets for the Spanish market during 1997. The results indicate that price changes in the underlying market lead the option market with the excep- tion of the crisis (Asian crisis) that took place in the stock markets around the world. Probably, differences on tra- ding platforms may have an influence

Pilar Corredor Casado; Rafael Santamaría Aquilué

245

Geología y registros magnéticos entre arroyo La Tapera y Santa Clara del Mar, Mar del Plata  

Microsoft Academic Search

Geology and magnetic records between Arroyo La Tapera and Santa Clara del Mar, Mar del Plata. Paleomagnetic studies were carried out in Pleistocene-Holocene sedimentary sequences exposed between Arroyo La Tapera and Santa Clara del Mar in Mar del Plata. The sediments exposed in the lower part of the La Tapera and Camet sections, which apparently belong to the Ensenada Formation,

Juan Carlos BIDEGAIN; Margarita L. OSTERRIETH; Adrianus J. VAN VELZEN; Yamile RICO

246

Relação entre mercado de terras, crescimento econômico e insegurança fundiária explicada por um modelo a \\  

Microsoft Academic Search

Relationship between the land market, economic growth and land insecurity explained by an overlapping model. In this paper, we analyze the relationship bet- ween the land market failures and the economic growth in Brazil, starting from an overlapping model including two sectors: agricultural and industrial. The land is both a specific factor for agriculture and an asset that can be

Claudio Araujo; Catherine Araujo Bonjean; Jean-Louis Combes; Pascale Combes Motel

2006-01-01

247

Alcohólicos Anónimos (AA): aspectos relacionados con la adherencia (afiliación) y diferencias entre recaídos y no recaídos  

Microsoft Academic Search

SUMMARY The work of Alcoholics Anonymous (AA) in fighting against alcohol abuse and alcoholism has placed it as an institution of great importance in Mexico and around the world. Although its labor has been subject for controversy, there is a lot of evidence that frequent attendance and affiliation to the groups and sessions can be very helpful for many individuals.

Reyna Gutiérrez Reynaga; Patricia Andrade Palos; Alberto Jiménez Tapia; Gabriela Saldívar Hernández; Francisco Juárez García

2009-01-01

248

La Communicacion entre los Centros de Investigacion en Educacion (Communication among Educational Research Centers).  

ERIC Educational Resources Information Center

In Latin America there is a lack of communication concerning educational research. This lack has been underlined in many regional meetings, but no action has been taken. Possible steps that would lead to improvement include circulation of research summaries, both for completed and current works, efforts by research centers to organize meetings,…

Schiefelbein, Ernesto

1972-01-01

249

Surveillance sentinelle du VIH chez les femmes enceintes en Mauritanie entre 2001 et 2007  

Microsoft Academic Search

Résumé  Selon le rapport 2008 sur l’épidémie de sida dans le monde, 33 millions de personnes vivent avec le VIH\\/ sida. L’Afrique intertropicale\\u000a est la région du globe la plus touchée. Le premier cas de sida en Mauritanie a été décrit en 1987. La prévalence nationale\\u000a du VIH\\/sida dans le pays est estimée à moins de 1 %. La surveillance sérologique

F. Z. Fall-Malick; A. O. Bara; M. Lam; M. Mint Beibacar; K. Ba; H. Ba; I. Ould Ghady; A. Ould Horma; N. C. Toure-Kane; S. Mboup; B. Lo

2010-01-01

250

Interactions between antiepileptic drugs and herbal medicines (Interacciones entre fármacos antiepilépticos y medicinas herbales)  

Microsoft Academic Search

As a therapeutic class, antiepileptic drugs (AEDs) have a high propensity to interact and many interactions with concomitant medications have been described. Increasingly, herbal medicines are often used by patients with epilepsy and the risk that these may interact with their AED medication is now being realised. The purpose of this review is to highlight the interactions that have been

Cecilie JOHANNESSEN LANDMARK; Philip N. PATSALOS

2008-01-01

251

Entre Dos Mundos/Between Two Worlds: Bicultural Development in Context  

ERIC Educational Resources Information Center

How do Mexican immigrant adolescents balance different, and often oppositional, cultural influences in the acculturation process? In this article, we explore how acculturating adolescents absorb cultural messages and go about creating their (multiple) identities. Guided by Alternation Theory, in-depth qualitative interviews were conducted with 12…

Bacallao, Martica L.; Smokowski, Paul R.

2009-01-01

252

Le Danois et l'entre-deux-mondes (Danish and "Betweeness").  

ERIC Educational Resources Information Center

Phonological, syntactic, and morphological aspects of Danish are viewed as symbolic and representative of the geographic, geological, and meteorological "betweeness" or versatility of the country and its culture. (MSE)

Van Lier, Henri

1990-01-01

253

Códigos éticos: análisis de la eficacia de su implantación entre las empresas españolas cotizadas  

Microsoft Academic Search

Ethical codes: analysing the efficacy of implantation amongst quoted Spanish companies Ethical codes or internal corporate social responsibility (CSR) codes proliferate in the business world within the context of the debate about self-regulation as an alternative or complement to traditional regulation. They are drawn up, supervised and controlled within the bosom of a company and at its insistence. This article

Carmen Valor; Alberto Aguilera

254

Correlación entre dimensiones de personalidad de marca y la marca emocional. Estudio en Cadena de Farmacias  

Microsoft Academic Search

The main objective of this article is to explore whether or not a relation exists between the theoretical concept of a brand personality and an emotional brand. The product of reference was a pharmacy franchise chain. The research adopted a non-probability sampling by convenience, including 295 people. Correlational analysis of the data gathered by survey was made using Cronbach's alpha

Saavedra Torres; José Luis; Oscar Colmenares

255

Actividades interrelacionadas entre el nino y la familia (Interrelated Activities between the Child and the Family).  

ERIC Educational Resources Information Center

Offers a rationale for parent involvement in early childhood education. Describes the benefits of mother-child gymnastics in terms of the development of motor skills and positive attitudes toward school. Highlights particular exercises and games. (AC)

Veglio, Ana M.

1993-01-01

256

Félix Rebollo Sánchez, Antonio Machado entre la Literatura y el Periodismo  

Microsoft Academic Search

Volumen de carácter ensayístico centrado en la figura de Antonio Machado Ruiz, nacido en Sevilla y muerto en Collioure (Rosellón, Francia), mientras abandonaba España. Félix Rebollo trata de ofrecer en cuatro breves capítulos los rasgos definitorios de la obra poética del biografiado al tiempo que deja entrever las características del pensamiento político y de la filosofía social recogidas en la

María Encarnación Gómez Rojo

2011-01-01

257

Pour un échange entre psychanalyse et sciences de l'esprit  

Microsoft Academic Search

The debate concerns the commun object of psychoanalysis (PA) and neurosciences (NCS). PA and NCS constitute different methods of description, analysis and comprehension of a single reality, but each approach constructs a different representation of it because each is based upon a different methodology. Is PA a science or, to which kind of science does PA belong ? This point

Nicolas Georgieff

2005-01-01

258

Uso da maconha e suas representações sociais: estudo comparativo entre universitários  

Microsoft Academic Search

¶ ABSTRACT. The purpose of this research was to compare the social representations of university students who are getting their degree in the technological, health and law areas, on the use of marijuana. Sixty (60) university students took part in this re search, both sexes, aged from 22 to 30 years old. Semi-structured interviews were used and the collected material

Maria da Penha de L. Coutinho; Ludgleydson Fernandes de Araújo; Bernard Gontiès

2004-01-01

259

Le Pop Art aux États-Unis: entre subversion et conformisme  

Microsoft Academic Search

This paper analyzes Pop Art's oscillation between subversion and conformism. In fact, to some, it was an exaltation of the American way of life as it mirrored the general well-being that people living in an affluent society experienced. Conveyed by Pop Art, the media image of the American world seemed to celebrate, by fetishizing it, American society's self-image. However, the

Éliane Elmaleh

1997-01-01

260

Homicidios en Medellín, Colombia, entre 1990 y 2002: actores, móviles y circunstancias  

Microsoft Academic Search

In Medellín, Colombia, homicide has been the first cause of morbidity and mortality for 20 years. Medellín has the highest homicide rates of all major cities in Latin America. This study describes the victims, motives, and circumstances in homicides in Medellín from 1990 to 2002. The period included 55,365 homicides, of which 1,394 were randomly studied. Of this sample, 93.6%

Marleny Cardona; Héctor Iván García; Carlos Alberto Giraldo; María Victoria López; Clara Mercedes Suárez; Diana Carolina Corcho; Carlos Hernán Posada; María Nubia Flórez

2005-01-01

261

Cirugía menor ambulatoria dermatológica y crioterapia. Estudio comparativo entre un dermatólogo y médicos de familia  

Microsoft Academic Search

IntroductionLack of diagnostic skill in cutaneous surgery may lead to erroneous and potentially detrimental therapies. This study compares the diagnosis and treatment in cutaneous surgery, including cryotherapy, between a dermatologist and family physicians.

J. Graells; A. Espinola; C. Barrio; M. D. Muñoz; A. Román; N. Parellada

2007-01-01

262

Etude du diagramme d'équilibre entre phases du système ternaire germanium-étain-tellure  

Microsoft Academic Search

The Ge?Sn?Te ternary system has been studied by thermal analysis (DTA and DSC), radiocrystallography on powders and metallography. No ternary compound has been found; the vertical section Ge?SnTe is a true pseudobinary section, while GeTe?SnTe presents a continuous solid solution.The study of six vertical sections allows us to identify two ternary reactions in the solid state (one of eutectoid type

L. Baldé; B. Legendre; A. Balkhi

1995-01-01

263

Relación entre actividad enzimática y biomasa de ensambles fitoplanctónicos en el sistema pelágico  

Microsoft Academic Search

In environments with drastically fluctuating conditions, physiological and biochemical adaptations can be important for the structuration of phytoplankton assemblages. The objective of this study was to establish whether the enzymatic activity of the phytoplankton, an indicator of its dominant internal metabolism, is related to the autotrophic biomass. The geographic study area covered the South Shetland Islands (62°S), Mejillones Bay (22°S),

José L. Iriarte; Renato A. Quiñones; Rodrigo R. González; Cynthia P. Valenzuela

2007-01-01

264

Induction de préséances entre bourgeons cotylédonaires par des stimulations mécaniques chez Bidens pilosus L  

Microsoft Academic Search

\\u000a Abstract  Pricking one of the cotyledons of aBidens pilosus L. (var.radiatus) seedling decapitated just above the cotyledons four times in succession induces after one minute the dominance of buds on\\u000a the unaffected side.

Marie Odile Desbiez

1971-01-01

265

Correlations entre les proprietes physico-mecaniques des roches et le comportement des granulats manufactures  

Microsoft Academic Search

\\u000aRsum  La revue des essais d'acceptation des granulats, quant leur qualit mcanique ou leur rsistance aux agents atmosphriques,\\u000a montre qu'il existe de trs nombreux essais empiriques en usage dans le monde mais pratiquement aucun n'est employ universellement.\\u000a Dans cette communication il est pass en revue les divers modes de sollicitation imposs au granulat depuis sa production\\u000a en carrire jusqu' son emploi,

Ballivy Gérard; Dayre Michel

1984-01-01

266

Entre analyse linguistique et théorie générale du droit: La Nomographie de Jeremy Bentham  

Microsoft Academic Search

Résumé  Les travaux récents ont permis de rendre justice à la théorie du langage qu’a élaborée Bentham et d’expliquer les enjeux théoriques\\u000a de son attachement aux mots. Il est donc désormais possible de s’attacher à comprendre les enjeux langagiers à l’oeuvre dans\\u000a les différents champs de la pensée benthamienne, et plus particulièrement au sein de sa théorie générale du droit. Dès

Malik Bozzo-Rey

2009-01-01

267

Effet du flux massique sur les mecanismes d'echange entre deux sous-canaux interconnectes  

Microsoft Academic Search

The present work is under taken in order to improve the knowledge on the hydrodynamic behavior of flow through rod bundles. Focus will be on the study of diffusion mechanisms under different flow conditions reaching hydrodynamic equilibrium, i.e., no net mass transfer between subchannels. This research is divided in two parts. The first one is devoted to the experimental study

Abbes Bellil

1998-01-01

268

Uso del condón entre adolescentes mexicanos para la prevención de las infecciones de transmisión sexual  

Microsoft Academic Search

Objective. To investigate the current sexual behavior and condom use during the first sexual intercourse among adolescents, as well as variations and factors influencing condom use at first sexual intercourse. Material and Methods. The data source for this study was Mexico's National Health Survey 2000. Study subjects were male and female adolescents aged 12 to 19 years (n=16,258). Statistical analysis

Cecilia Gayet; Fátima Juárez; Laura A. Pedrosa; Carlos Magis

2003-01-01

269

Biologie comparée des interactions entre les macrophages et Trypanosoma cruzi, Leishmania spp. et Toxoplasma gondii  

Microsoft Academic Search

Macrophages have a central role in the immune system by eliminating a lot of pathogens. Nevertheless, they are often infected by pathogenic microorganisms in particular parasitic protozoa. They thus play the role of host cell by harbouring the intracellular survival and multiplication of these pathogens. Various mechanisms (receptors\\/ligands interactions, enzymes…) are involved in recognition and adhesion steps. When suitably activated,

Bernard Vray

1998-01-01

270

Informer le patient en psychiatrie : entre pratique clinique et réflexion anthropologique  

Microsoft Academic Search

Social isolation has got to be one of the greatest losses in mental illness. For many authors, people with mental disease can have no friends, no spouse, and sometimes no family. Two thirds of patients with schizophrenia return to their parents’ house when discharged from a hospital after the first psychotic fit. Family members generally receive very little education as

A. Olivero; J. Palazzolo

2008-01-01

271

Asociación entre el virus XMRV y enfermedades humanas: preguntas y respuestas  

Cancer.gov

El XMRV es un retrovirus del que se informó por primera vez en 2006 como una causa potencial del cáncer de próstata. Está estrechamente relacionado con los virus de leucemia murina, los cuales causan una amplia variedad de cánceres así como enfermedades inmunológicas y neurológicas en ratones.

272

A relação entre escolaridade e ocupação dos jovens no Distrito Federal: Uma análise socioespacial  

Microsoft Academic Search

A ocupação territorial no Distrito Federal (DF) é marcada pela segregação socioespacial. Por conta da segregação, a dinâmica interna de ocupação originou uma organização espacial diferenciada das demais cidades do país, na qual a restrição à população é visível aos olhos, embora não se deixe desvelar totalmente. A concentração dos postos de trabalho no Plano Piloto e a exigência cada

Sílvia Silva; Cavalcante Leite; Karla Christina; Batista de França

273

Les opérations de restructuration des firmes agroalimentaires multinationales entre 1987 et 2003  

Microsoft Academic Search

Based on a neo-institutionalist theoretical framework and using the Agrodata databank, the present paper analyses the main drivers underlying the restructuring operations of the top 100 multinational food processing enterprises worldwide and draws the map of the world's new agri-food landscape. World's agri-food oligopoly came out during these last decades concentrating an ever increasing financial and economic power (in 2002,

N. Ayadi; J. L. Rastoin; S. Tozanli

2006-01-01

274

Legume Lectins Inhibit Human Parainfluenza Virus Type 2 Infection by Interfering with the Entr  

PubMed Central

Three lectins with different sugar binding specificities were investigated for anti-viral activity against human parainfluenza virus type 2 (hPIV-2). The lectins, concanavalin A (Con A), lens culinaris agglutinin (LCA) and peanut agglutinin (PNA), inhibited cell fusion and hemadsorption induced by hPIV-2. Virus nucleoprotein (NP) gene synthesis was largely inhibited, but fusion (F) and hemagglutinin-neuraminidase (HN) gene syntheses were not. An indirect immunofluorescence study showed that Con A inhibited virus NP, F and HN protein syntheses, but LCA did not completely inhibit them, and that PNA inhibited only NP protein synthesis. Using a recombinant green fluorescence protein-expressing hPIV-2, without matrix protein (rghPIV-2?M), it was found that virus entry into the cells was not completely prevented. The lectins considerably reduced the number of viruses released compared with that of virus infected cells. The lectins bound to cell surface within 10 min, and many aggregates were observed at 30 min. Con A and LCA slightly disrupted actin microfilaments and microtubules, but PNA had almost no effect on them. These results indicated that the inhibitory effects of the lectins were caused mainly by the considerable prevention of virus adsorption to the cells by the lectin binding to their receptors.

Uematsu, Jun; Koyama, Aoi; Takano, Sayaka; Ura, Yukari; Tanemura, Miho; Kihira, Sahoko; Yamamoto, Hidetaka; Kawano, Mitsuo; Tsurudome, Masato; O'Brien, Myles; Komada, Hiroshi

2012-01-01

275

L'Harmonisation des langues maliennes: entre l'Integration nationale et régionale  

NASA Astrophysics Data System (ADS)

The standardization of Malian languages, which began in the period after independence, has been an educational reform guided more by linguists than by any institutional framework laid down by the political authorities of the country. This situation has permitted the technical application of a scientific strategy, but it has not led to widespread and general acceptance of the formulas which have been worked out. The consequent opposition between technical and political considerations, which have admittedly not always been in conflict, has been complicated by a set of additional factors which have made it difficult to reconcile internal (national) harmonization, dictated by local tendencies and balances between languages, and the need to respect the (regional) ecolinguistics of the country, whose linguistic and sociocultural divisions frequently extend well into other countries of the sub-region. This conflict is illustrated by the example of Malian languages with a wide regional distribution — Bamanan (Bambara) and Fulfulde (Fulani) — and by that of languages with a narrower distribution such as Bomu and Syenara-Mamara. The standardization of orthography and the creation of terminology in the MAPE (Mandingo-Peul) Project are the manifestation of a general acceptance of regionalism, while the choice of central, standard languages has often been made without regard for regional factors.

Ouane, Adama

1991-03-01

276

Technological Advancement Development of a Fusarium graminearum AVymetrix GeneChip for proWling fungal gene expression in vitro and in planta  

Microsoft Academic Search

Recently the genome sequences of several Wlamentous fungi have become available, providing the opportunity for large-scale func- tional analysis including genome-wide expression analysis. We report the design and validation of the Wrst AVymetrix GeneChip micro- array based on the entire genome of a Wlamentous fungus, the ascomycetous plant pathogen Fusarium graminearum. To maximize the likelihood of representing all putative genes

Ulrich Güldener; Kye-Yong Seong; Jayanand Boddu; Seungho Cho; Frances Trail; Jin-Rong Xu; Gerhard Adam; Hans-Werner Mewes

277

Selective interaction of triazole derivatives with DWF4, a cytochrome P450 monooxygenase of the brassinosteroid biosynthetic pathway, correlates with brassinosteroid deficiency in planta.  

PubMed

Brassinazole, a synthetic chemical developed in our laboratory, is a triazole-type brassinosteroid biosynthesis inhibitor that induces dwarfism in various plant species. The target sites of brassinazole were investigated by chemical analyses of endogenous brassinosteroids (BRs) in brassinazole-treated Catharanthus roseus cells. The levels of castasterone and brassinolide in brassinazole-treated plant cells were less than 6% of the levels in untreated cells. In contrast, campestanol and 6-oxocampestanol levels were increased, and levels of BR intermediates with hydroxy groups on the side chains were reduced, suggesting that brassinazole treatment reduced BR levels by inhibiting the hydroxylation of the C-22 position. DWF4, which is an Arabidopsis thaliana cytochrome P450 isolated as a putative steroid 22-hydroxylase, was expressed in Escherichia coli, and the binding affinity of brassinazole and its derivatives to the recombinant DWF4 were analyzed. Among several triazole derivatives, brassinazole had both the highest binding affinity to DWF4 and the highest growth inhibitory activity. The binding affinity and the activity for inhibiting hypocotyl growth were well correlated among the derivatives. In brassinazole-treated A. thaliana, the CPD gene involved in BR biosynthesis was induced within 3 h, most likely because of feedback activation caused by the reduced levels of active BRs. These results indicate that brassinazole inhibits the hydroxylation of the C-22 position of the side chain in BRs by direct binding to DWF4 and that DWF4 catalyzes this hydroxylation reaction. PMID:11319239

Asami, T; Mizutani, M; Fujioka, S; Goda, H; Min, Y K; Shimada, Y; Nakano, T; Takatsuto, S; Matsuyama, T; Nagata, N; Sakata, K; Yoshida, S

2001-07-13

278

Time-Resolved Fluorescence Imaging Reveals Differential Interactions of N-Glycan Processing Enzymes across the Golgi Stack in Planta1[W][OA  

PubMed Central

N-Glycan processing is one of the most important cellular protein modifications in plants and as such is essential for plant development and defense mechanisms. The accuracy of Golgi-located processing steps is governed by the strict intra-Golgi localization of sequentially acting glycosidases and glycosyltransferases. Their differential distribution goes hand in hand with the compartmentalization of the Golgi stack into cis-, medial-, and trans-cisternae, which separate early from late processing steps. The mechanisms that direct differential enzyme concentration are still unknown, but the formation of multienzyme complexes is considered a feasible Golgi protein localization strategy. In this study, we used two-photon excitation-Förster resonance energy transfer-fluorescence lifetime imaging microscopy to determine the interaction of N-glycan processing enzymes with differential intra-Golgi locations. Following the coexpression of fluorescent protein-tagged amino-terminal Golgi-targeting sequences (cytoplasmic-transmembrane-stem [CTS] region) of enzyme pairs in leaves of tobacco (Nicotiana spp.), we observed that all tested cis- and medial-Golgi enzymes, namely Arabidopsis (Arabidopsis thaliana) Golgi ?-mannosidase I, Nicotiana tabacum ?1,2-N-acetylglucosaminyltransferase I, Arabidopsis Golgi ?-mannosidase II (GMII), and Arabidopsis ?1,2-xylosyltransferase, form homodimers and heterodimers, whereas among the late-acting enzymes Arabidopsis ?1,3-galactosyltransferase1 (GALT1), Arabidopsis ?1,4-fucosyltransferase, and Rattus norvegicus ?2,6-sialyltransferase (a nonplant Golgi marker), only GALT1 and medial-Golgi GMII were found to form a heterodimer. Furthermore, the efficiency of energy transfer indicating the formation of interactions decreased considerably in a cis-to-trans fashion. The comparative fluorescence lifetime imaging of several full-length cis- and medial-Golgi enzymes and their respective catalytic domain-deleted CTS clones further suggested that the formation of protein-protein interactions can occur through their amino-terminal CTS region.

Schoberer, Jennifer; Liebminger, Eva; Botchway, Stanley W.; Strasser, Richard; Hawes, Chris

2013-01-01

279

Comparison of the development in planta of a pyrrolnitrin-resistant mutant of Botrytis cinerea and its sensitive wild-type parent isolate  

Microsoft Academic Search

Botrytis cinerea is able to build-up resistance to pyrrolnitrin, an antibiotic produced by diverse biocontrol agents, possibly compromising\\u000a the durability of this method of disease control. The development of two near-isogenic lines of B. cinerea differing in their level of resistance to pyrrolnitrin was compared in tomato plants and on PDA medium. In tomato plants,\\u000a significant differences in the percentage

Sakhr Ajouz; Marc Bardin; Philippe C. Nicot; Mohamed El Maâtaoui

2011-01-01

280

Transient Co-Expression of Post-Transcriptional Gene Silencing Suppressors for Increased in Planta Expression of a Recombinant Anthrax Receptor Fusion Protein  

PubMed Central

Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin), CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA) domain of human capillary morphogenesis 2 (CMG2), an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG). We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS): p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI), with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI.

Arzola, Lucas; Chen, Junxing; Rattanaporn, Kittipong; Maclean, James M.; McDonald, Karen A.

2011-01-01

281

Artemisinin production in Artemisia annua: studies in planta and results of a novel delivery method for treating malaria and other neglected diseases  

PubMed Central

Artemisia annua L. produces the sesquiterpene lactone, artemisinin, a potent antimalarial drug that is also effective in treating other parasitic diseases, some viral infections and various neoplasms. Artemisinin is also an allelopathic herbicide that can inhibit the growth of other plants. Unfortunately, the compound is in short supply and thus, studies on its production in the plant are of interest as are low cost methods for drug delivery. Here we review our recent studies on artemisinin production in A. annua during development of the plant as it moves from the vegetative to reproductive stage (flower budding and full flower formation), in response to sugars, and in concert with the production of the ROS, hydrogen peroxide. We also provide new data from animal experiments that measured the potential of using the dried plant directly as a therapeutic. Together these results provide a synopsis of a more global view of regulation of artemisinin biosynthesis in A. annua than previously available. We further suggest an alternative low cost method of drug delivery to treat malaria and other neglected tropical diseases.

Arsenault, Patrick R.; Covello, Patrick S.; McMickle, Anthony; Teoh, Keat H.; Reed, Darwin W.

2010-01-01

282

Antimicrobial activity and phytochemical studies of some medicinal plants from Ghana Actividad antimicrobiana y estudios fitoquímicos de algunas plantas medicinales de Ghana  

Microsoft Academic Search

The methanol and petroleum ether extracts of the leaf and stem bark of Nauclea latifolia, Bridelia atroviridis and Zanthoxylum gilletii showed antimicrobial activity against the test organisms. The methanol extracts of the plants exhibited higher activity than the pet ether extract against the test organisms. The activity of the extracts may support some of the folkloric uses of these plants

C AGYARE; A Y MENSAH

2006-01-01

283

Regulon studies and in planta role of the BraI/R quorum-sensing system in the plant-beneficial Burkholderia cluster.  

PubMed

The genus Burkholderia is composed of functionally diverse species, and it can be divided into several clusters. One of these, designated the plant-beneficial-environmental (PBE) Burkholderia cluster, is formed by nonpathogenic species, which in most cases have been found to be associated with plants. It was previously established that members of the PBE group share an N-acyl-homoserine lactone (AHL) quorum-sensing (QS) system, designated BraI/R, that produces and responds to 3-oxo-C14-HSL (OC14-HSL). Moreover, some of them also possess a second AHL QS system, designated XenI2/R2, producing and responding to 3-hydroxy-C8-HSL (OHC8-HSL). In the present study, we performed liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis to determine which AHL molecules are produced by each QS system of this group of bacteria. The results showed that XenI2/R2 is mainly responsible for the production of OHC8-HSL and that the BraI/R system is involved in the production of several different AHLs. This analysis also revealed that Burkholderia phymatum STM815 produces greater amounts of AHLs than the other species tested. Further studies showed that the BraR protein of B. phymatum is more promiscuous than other BraR proteins, responding equally well to several different AHL molecules, even at low concentrations. Transcriptome studies with Burkholderia xenovorans LB400 and B. phymatum STM815 revealed that the BraI/R regulon is species specific, with exopolysaccharide production being the only common phenotype regulated by this system in the PBE cluster. In addition, BraI/R was shown not to be important for plant nodulation by B. phymatum strains or for endophytic colonization and growth promotion of maize by B. phytofirmans PsJN. PMID:23686262

Coutinho, Bruna G; Mitter, Birgit; Talbi, Chouhra; Sessitsch, Angela; Bedmar, Eulogio J; Halliday, Nigel; James, Euan K; Cámara, Miguel; Venturi, Vittorio

2013-07-01

284

Interaction of VPg-Pro of Turnip mosaic virus with the translation initiation factor 4E and the poly(A)-binding protein in planta  

Microsoft Academic Search

The viral protein linked to the genome (VPg) of Turnip mosaic virus (TuMV) interacts in vitro with the translation eukaryotic initiation factor (eIF) 4E. In the present study, we investigated the consequence of TuMV infection on eIF4E expression. Two isomers are present in plants, namely eIF4E and eIF(iso)4E. Expression of the latter was detected in both TuMV-infected and mock-inoculated Brassica

Simon Leonard; Catherine Viel; Chantal Beauchemin; Nicole Daigneault; Marc G. Fortin; Jean-Francois Laliberte

2004-01-01

285

In planta PCR-based detection of early infection of plant-parasitic nematodes in the roots: a step towards the understanding of infection and plant defence  

Microsoft Academic Search

The polyphagous obligate parasites Meloidogyne spp. devastate a wide range of crop plants including bananas and plantains. Their infestations impact agriculture worldwide. Therefore,\\u000a an effective combating regime against this nematode species and an in-depth understanding of plant-nematode interaction are\\u000a essential. Early detection of infection by visual inspection is not possible. This hampers early control strategy efforts\\u000a and makes in-depth research

Syarifah Aisyafaznim Sayed Abdul Rahman; Zulqarnain Mohamed; Rofina Yasmin Othman; Rony Swennen; Bart Panis; Dirk De Waele; Serge Remy; Sebastien Christian Carpentier

2010-01-01

286

Artemisinin production in Artemisia annua : studies in planta and results of a novel delivery method for treating malaria and other neglected diseases  

Microsoft Academic Search

Artemisia annua L. produces the sesquiterpene lactone, artemisinin, a potent antimalarial drug that is also effective in treating other parasitic\\u000a diseases, some viral infections and various neoplasms. Artemisinin is also an allelopathic herbicide that can inhibit the\\u000a growth of other plants. Unfortunately, the compound is in short supply and thus, studies on its production in the plant are\\u000a of interest

Pamela J. WeathersPatrick; Patrick R. Arsenault; Patrick S. Covello; Anthony McMickle; Keat H. Teoh; Darwin W. Reed

2011-01-01

287

EFECTO RESIDUAL DE LA ROCA FOSFÓRICA DE RIECITO MODIFICADA POR CALCINACIÓN O ACIDULACIÓN SOBRE PLANTAS DE MAÍZ EN SUELOS CON NIVEL VARIABLE DE CALCIO1  

Microsoft Academic Search

Residual effect of acidulated or burnt Riecito phosphoric rock on maize grown in soils with variable levels of calcium With the purpose of evaluating the residual effect of phosphoric rock from Riecito (Venezuela) treated with vinaza or high temperatures, three successive crops of corn, used as indicative plant, were grown in an acid soil (pH 3.7) whitewashed up to pH

Shirley M. Fernández; Carlos A. Meza

2004-01-01

288

Efficient foreign gene expression in planta using a plantago asiatica mosaic virus-based vector achieved by the strong RNA-silencing suppressor activity of TGBp1.  

PubMed

Plant virus expression vectors provide a powerful tool for basic research as well as for practical applications. Here, we report the construction of an expression vector based on plantago asiatica mosaic virus (PlAMV), a member of the genus Potexvirus. Modification of a vector to enhance the expression of a foreign gene, combined with the use of the foot-and-mouth disease virus 2A peptide, allowed efficient expression of the foreign gene in two model plant species, Arabidopsis thaliana and Nicotiana benthamiana. Comparison with the widely used potato virus X (PVX) vector demonstrated that the PlAMV vector retains an inserted foreign gene for a longer period than PVX. Moreover, our results showed that the GFP expression construct PlAMV-GFP exhibits stronger RNA silencing suppression activity than PVX-GFP, which is likely to contribute to the stability of the PlAMV vector. PMID:24154949

Minato, Nami; Komatsu, Ken; Okano, Yukari; Maejima, Kensaku; Ozeki, Johji; Senshu, Hiroko; Takahashi, Shuichiro; Yamaji, Yasuyuki; Namba, Shigetou

2014-05-01

289

Validation of RT-qPCR reference genes for in planta expression studies in Hemileia vastatrix, the causal agent of coffee leaf rust  

Microsoft Academic Search

Hemileia vastatrix is a biotrophic fungus, causing coffee leaf rust in all coffee growing countries, leading to serious social and economic problems. Gene expression studies may have a key role unravelling the transcriptomics of this pathogen during interaction with the plant host. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) is currently the golden standard for gene expression analysis, although

Ana Vieira; Pedro Talhinhas; Andreia Loureiro; Sébastien Duplessis; Diana Fernandez; Maria do Céu Silva; Octávio S. Paulo; Helena Gil Azinheira

2011-01-01

290

Perdas do nitrogŒnio da urØia no sistema solo-planta em dois ciclos de cana-de-aÁœcar (1)  

Microsoft Academic Search

Nitrogen losses of applied urea in the soil-plant system during two sugar cane cycles Abstract†ñ†The objective of this work was to quantify the losses of N from the soil-plant system, in the cane†plant and sugar cane ratoon-cycle. Two experiments were carried out in 220†L-pots filled with sandy soil. In the experiment with cane plant two factors were studied: two types

Paulo Cesar Ocheuze Trivelin; Mauro Wagner de Oliveira; Cesar Vitti

2002-01-01

291

Irradiacion de meristemos 'in vitro' para inducir mutaciones en plantas de ornato (Petunia hybrida). (Induced mutations in ornamental plants by 'in vitro' irradiation of Petunia hybrida meristems).  

National Technical Information Service (NTIS)

In recent decades it has been observed that for the induction of mutation in ornamental plants we can obtain better results when the plants are irradiated in vegetative state and even better 'in vitro' that when its are irradiated 'in vivo'. In this work ...

J. Gonzalez-Jimenez

1993-01-01

292

A Robust and Sensitive Synthetic Sensor to Monitor the Transcriptional Output of the Cytokinin Signaling Network in Planta1[C][W][OA  

PubMed Central

Cytokinins are classic plant hormones that orchestrate plant growth, development, and physiology. They affect gene expression in target cells by activating a multistep phosphorelay network. Type-B response regulators, acting as transcriptional activators, mediate the final step in the signaling cascade. Previously, we have introduced a synthetic reporter, Two Component signaling Sensor (TCS)::green fluorescent protein (GFP), which reflects the transcriptional activity of type-B response regulators. TCS::GFP was instrumental in uncovering roles of cytokinin and deepening our understanding of existing functions. However, TCS-mediated expression of reporters is weak in some developmental contexts where cytokinin signaling has a documented role, such as in the shoot apical meristem or in the vasculature of Arabidopsis (Arabidopsis thaliana). We also observed that GFP expression becomes rapidly silenced in TCS::GFP transgenic plants. Here, we present an improved version of the reporter, TCS new (TCSn), which, compared with TCS, is more sensitive to phosphorelay signaling in Arabidopsis and maize (Zea mays) cellular assays while retaining its specificity. Transgenic Arabidopsis TCSn::GFP plants exhibit strong and dynamic GFP expression patterns consistent with known cytokinin functions. In addition, GFP expression has been stable over generations, allowing for crosses with different genetic backgrounds. Thus, TCSn represents a significant improvement to report the transcriptional output profile of phosphorelay signaling networks in Arabidopsis, maize, and likely other plants that display common response regulator DNA-binding specificities.

Zurcher, Evelyne; Tavor-Deslex, Deborah; Lituiev, Dmytro; Enkerli, Katalin; Tarr, Paul T.; Muller, Bruno

2013-01-01

293

In Planta Recognition of a Double-Stranded RNA Synthesis Protein Complex by a Potexviral RNA Silencing Suppressor[C][W][OPEN  

PubMed Central

RNA silencing plays an important antiviral role in plants and invertebrates. To counteract antiviral RNA silencing, most plant viruses have evolved viral suppressors of RNA silencing (VSRs). TRIPLE GENE BLOCK PROTEIN1 (TGBp1) of potexviruses is a well-characterized VSR, but the detailed mechanism by which it suppresses RNA silencing remains unclear. We demonstrate that transgenic expression of TGBp1 of plantago asiatica mosaic virus (PlAMV) induced developmental abnormalities in Arabidopsis thaliana similar to those observed in mutants of SUPPRESSOR OF GENE SILENCING3 (SGS3) and RNA-DEPENDENT RNA POLYMERASE6 (RDR6) required for the trans-acting small interfering RNA synthesis pathway. PlAMV-TGBp1 inhibits SGS3/RDR6-dependent double-stranded RNA synthesis in the trans-acting small interfering RNA pathway. TGBp1 interacts with SGS3 and RDR6 and coaggregates with SGS3/RDR6 bodies, which are normally dispersed in the cytoplasm. In addition, TGBp1 forms homooligomers, whose formation coincides with TGBp1 aggregation with SGS3/RDR6 bodies. These results reveal the detailed molecular function of TGBp1 as a VSR and shed new light on the SGS3/RDR6-dependent double-stranded RNA synthesis pathway as another general target of VSRs.

Okano, Yukari; Senshu, Hiroko; Hashimoto, Masayoshi; Neriya, Yutaro; Netsu, Osamu; Minato, Nami; Yoshida, Tetsuya; Maejima, Kensaku; Oshima, Kenro; Komatsu, Ken; Yamaji, Yasuyuki; Namba, Shigetou

2014-01-01

294

In planta protein interactions of three alphacryptoviruses and three betacryptoviruses from White Clover, Red Clover and Dill by bimolecular fluorescence complementation analysis.  

PubMed

Plant-infecting viruses of the genera Alpha- and Betacryptovirus within the family Partitiviridae cause no visible effects on their hosts and are only transmitted by cell division and through gametes. The bipartite dsRNA genome is encoding a RNA-dependent RNA polymerase (RdRp) and a coat protein (CP). Aside from sequence and structural analysis, the investigation of protein interactions is another step towards virus characterization. Therefore, ORFs of two type members White Clover Cryptic Virus 1 and 2 (WCCV-1 and WCCV-2), as well as the related viruses from Red Clover and Dill were introduced into a bimolecular fluorescence complementation assay. We showed CP-CP dimerization for all tested viruses with localization for alphacryptoviruses at the nuclear membrane and for betacryptoviruses close to cell walls within the cytoplasm. For CPs of WCCV-1 and WCCV-2, deletion mutants were created to determine internal interaction sites. Moreover, RdRp self-interaction was found for all viruses, whereas CP-RdRp interactions were only detectable for the alphacryptoviruses. An intra-genus test of CPs was successful in various virus combinations, whereas an inter-genus interaction of WCCV-1CP and WCCV-2CP was absent. This is the first report of in vivo protein interactions of members in the family Partitiviridae, indicating distinct features of the alpha- and betacryptoviruses. PMID:24113719

Lesker, Till; Maiss, Edgar

2013-10-01

295

The 20S proteasome ?5 subunit of Arabidopsis thaliana carries an RNase activity and interacts in planta with the lettuce mosaic potyvirus HcPro protein.  

PubMed

In plants, the ubiquitin/26S proteasome system (UPS) plays a central role in protein degradation and is involved in many steps of defence mechanisms, regardless of the types of pathogen targeted. In addition to its proteolytic activities, the UPS ribonuclease (RNase) activity, previously detected in 20S proteasome preparations from cauliflower and sunflower (Helianthus annuus), has been shown to specifically target plant viral RNAs in vitro. In this study, we show that recombinant Arabidopsis thaliana proteasomal ?(5) subunit expressed in Escherichia coli harbours an RNase activity that degrades Tobacco mosaic virus (TMV, Tobamovirus)- and Lettuce mosaic virus (LMV, Potyvirus)-derived RNAs in vitro. The analysis of mutated forms of the ?(5) subunit demonstrated that mutation of a glutamic acid at position 110 affects RNase activity. Furthermore, it was demonstrated, using a bimolecular fluorescence complement assay, that the multifunctional helper component proteinase (HcPro) of LMV, already known to interfere with the 20S proteasome RNase activity in vitro, can interact in vivo with the recombinant ?(5) subunit. Further experiments demonstrated that, in LMV-infected lettuce cells, ?(5) is partially relocalized to HcPro-containing infection-specific inclusions. Susceptibility analyses of Arabidopsis mutants, knocked out for each At-PAE gene encoding ?(5) , showed that one (KO-pae1) of the two mutants exhibited a significantly increased susceptibility to LMV infection. Taken together, these results extend to A. thaliana ?(5) the range of HcPro-interacting proteasomal subunits, and suggest that HcPro may modulate its associated RNase activity which may contribute to an antiviral response. PMID:21199564

Dielen, Anne-Sophie; Sassaki, Flavio Tetsuo; Walter, Jocelyne; Michon, Thierry; Ménard, Guillaume; Pagny, Gaëlle; Krause-Sakate, Renate; Maia, Ivan De Godoy; Badaoui, Saloua; Le Gall, Olivier; Candresse, Thierry; German-Retana, Sylvie

2011-02-01

296

Transient co-expression of post-transcriptional gene silencing suppressors and beta-glucuronidase in harvested lettuce leaf tissue does not improve recombinant protein accumulation in planta.  

PubMed

Agrobacterium-mediated gene transfer was used to co-express three virus-derived post-transcriptional gene silencing (PTGS) suppressors, P19 from tomato bushy stunt virus and two species of helper component proteinase (HcPro) from tobacco etch virus (TEV) and turnip mosaic virus, with beta-glucuronidase (GUS) in harvested lettuce leaf tissue to investigate whether GUS accumulation increases in the presence of PTGS suppressors. Co-expression incubations were 3-5 days at 4 and 22 degrees C. GUS activity and leaf viability were measured after incubation. Co-expression of PTGS suppressors did not elevate GUS expression levels. Under certain incubation conditions, co-expression of TEV HcPro significantly lowered transient GUS expression and was detrimental to leaf viability, suggesting that expression of PTGS silencers may have a negative effect on transient expression levels that outweighs any effects of PTGS suppression in harvested leaf tissues. PMID:17206371

Simmons, Christopher W; VanderGheynst, Jean S

2007-04-01

297

A semi-quantitative RT-PCR method to readily compare expression levels within Botrytis cinerea multigenic families in vitro and in planta  

Microsoft Academic Search

A straightforward and easy-to-apply semi-quantitative RT-PCR method was developed to study multigenic expression in the phytopathogenic fungus Botrytis cinerea. This procedure is based on the one-step reverse transcription-amplification of a specific transcript within total RNA and product amount determination by densitometric analysis of ethidium bromide fluorescence upon gel electrophoresis. The semi-quantitative analysis is achieved, at a fixed PCR cycle-number, within

Mathias Choquer; Martine Boccara; Anne Vidal-Cros

2003-01-01

298

The Uromyces fabae UfAAT3 gene encodes a general amino acid permease that prefers uptake of in planta scarce amino acids.  

PubMed

SUMMARY The obligately biotrophic rust fungi are dependent on nutrient supply from their host plants. A cDNA library of infection structures of the rust fungus Uromyces fabae was used to identify a gene (UfAAT3) that encodes a protein with a high degree of sequence similarity to fungal amino acid permeases. The expression profile revealed by RT-PCR shows an up-regulation very early during rust development, with the highest level in haustoria and infected leaves. Heterologous expression of UfAAT3p in Xenopus oocytes revealed an amino acid permease energized by co-transport with protons and exhibiting a broad substrate specificity. Compared to the previously described U. fabae amino acid transporter (AAT1), which represented the highest transport activities for lysine and histidine, electrophysiological measurements with cRNA of UfAAT3-injected oocytes showed substrate preferences for leucine and the sulphur containing amino acids methionine and cysteine. The unique contribution of the amino acid permeases and their substrate affinities might be connected with the availability of amino acids in the leaf tissue. Thus, in order to compare the substrate profiles of AAT1p and UfAAT3p with the natural environment of U. fabae we analysed the amino acid concentration in the apoplastic space, in addition to that in extracts of Vicia faba leaves. The predominant free amino acids were asparagine, alanine, glutamine and glutamate. However, most amino acids were present at low concentrations (between 0.02 and 0.16 mm), including the preferred substrates of the U. fabae amino acid permeases AAT1p and UfAAT3p. PMID:20565608

Struck, Christine; Mueller, Elena; Martin, Holger; Lohaus, Gertrud

2004-05-01

299

Proteccion de aceros al carbono en plantas G.S. (Girldler sulphide): Pte. 7. Efectos de la exposicion al medio ambiente de las capas protectoras de sulfuros y posterior tratamiento en condiciones de planta. (Carbon steel protection in G.S. (Girldler sulphide) plants: Pt. 7. Environment exposure effects on iron sulphide scales and subsequent treatment in plant conditions).  

National Technical Information Service (NTIS)

In order to protect carbon steel towers and piping of a GS experimental heavy water plant against corrosion produced by the action of aqueous solutions of hydrogen sulphide, a method, elsewhere published, was developed. Carbon steel exposed to saturated a...

O. Lires C. Delfino E. Rojo

1989-01-01

300

Comparación entre tres métodos manuales empleados en la cuenta diferencial de leucocitos respecto a un equipo automatizado  

Microsoft Academic Search

Introduction Introduction Introduction Introduction Introduction. Leukocyte differential counts, based in blood films is a routinely method in clinical laboratories, however, results are imprecise and biased, particularly for big cells and cells circulating in small number. Objective Objective Objective Objective Objective. Comparison between results obtained from three manual methods, based in blood films review, and the results obtained from a cell

Eduardo Brambila; Rosalba Castillo-Guerra; Patricia Lozano-Zarain

2003-01-01

301

Les échanges industriels entre la France et les pays d'Europe centrale et orientale : premières tendances de la spécialisation  

Microsoft Academic Search

[ger] Der Industriehandel zwischen Frankreich und den mittel- und osteuropaischen Lândern: erste Spezialisierungstendenzen . Der Austausch zwischen Frankreich und den mittel- und sischen Exporte von Investitionsgùtem und High-Tech- osteuropâischen Lândern hat seit dem Zusammenbruch Erzeugnissen (Elektronikgeràte, Prazisionsinstrumente) des Rats fur Gegenseitige Wirtschaftshilfe (COMECON) gefôrdert. im Jahre 1990 stark zugenommen, wenn auch seine Handelstrôme mit diesen Lândern betragsmâBig noch . recht

Béatrice Colin-Sédillot

1994-01-01

302

Uso de imagens CBERS para avaliação da evolução da atividade de Carcinicultura em Sergipe entre 2005 e 2008  

Microsoft Academic Search

Brazilian coast, besides its great fauna and flora biodiversity, has favorable weather conditions to shrimp farming, an activity which has been increasing especially in the northeast of Brazil. The activity has caused the deforestation of mangrove areas, an important ecossystem to maintain the natural balance of coast biological diversity. The Brazilian Institute for the Environment and Renewable Natural Resources -

Raquel Barreto

303

Facteurs associés à l?opposition au don d’organes en France entre 1996 et 1999  

Microsoft Academic Search

Objective: The demand for organ transplantation exceeds organ donation in France and refusal to organ donation remains close to 30%. This study analysed risk factors associated with refusal of organ donation.Study design: Retrospective study.Patients: All potential organ donors registered by the French transplantation agency between 1996 and 1999 were included, excepted those with a contraindication to organ procurement or a

V Demiguel; C Boileau; S Cohen; D Noury; F Bonnet; P Tuppin

2001-01-01

304

Pourquoi faut-il < apprivoiser > la confiance entre tous pour cultiver un processus de developpement local durable ?  

PubMed

Un processus de développement territorial durable représente une organisation sociale caractérisée par son unicité propre au territoire d'implémentation. Cette notion de territoire constitue un fait humain dont le développement intègre le bien-être collectif et individuel au travers d'une démarche intersectorielle et pluridisciplinaire. Lors de la réalisation de projets communs, la dynamique partenariale peut transformer les relations interpersonnelles et favoriser l'émergence de liens de confiance au cœur du processus de développement local durable. Cette confiance engendre la constitution d'une intelligence territoriale collective basée sur les savoirs et savoir-faire individuels et sectoriels qui forme le patrimoine immatériel commun, pour chacun des sociétaires du processus de développement territorial durable. Mais cette confiance partenariale reste fragile car elle constitue un fait humain. PMID:24737811

Decoster, Dominique-Paule

2014-03-01

305

Asociación entre el polimorfismo genético de la interleucina-1? (3953 T\\/C) y la hernia discal lumbar sintomática  

Microsoft Academic Search

ObjectiveTo evaluate the association between the presence of the genotype of certain genetic polymorphisms (GP) of the cytokine and oxide nitric synthase (NOS) and the development of lumbar herniated disc (LHD).

J. Paz Aparicio; E. López-Anglada Fernández; H. Montes Prieto; J. Pena Vázquez; I. Fernández Bances; V. Folgueras Henriksen; P. López Fernández; J. C. López-Fanjúl Menéndez; E. Valle Garay; V. Asensi Álvarez

2010-01-01

306

Abordaje integral de un caso complejo de diabetes mellitus en domicilio entre la gestora de casos y la enfermera comunitaria  

Microsoft Academic Search

We present the case of a patient with long-term and clinically complex Diabetes Mellitus. She was taking part in the home care program in Primary Care. The complications of her DM affected her quality of life: blindness, kidney failure, treated with hemodialysis, and a cerebrovascular attack.We describe the evaluation following Virginia's Henderson model. This evaluation was made in the patient's

Marta Prats-Guardiola; Rosa María López-Pisa

2010-01-01

307

Tensión diplomática entre Colombia y Ecuador durante 2006-2009: una mirada desde la teoría de juegos  

Microsoft Academic Search

Resumen Este documento centra su análisis en la tensión diplomática que sostuvieron Colombia y Ecuador durante el periodo 2006-2009, a partir de las fumigaciones aéreas que Colombia realizó en la zona de frontera con el territorio ecuatoriano, así como el ataque realizado por el ejército colombiano al campamento de las Fuerzas armadas revolucionarias de colombia (Farc), en donde fue abatido

Santiago Arroyo Ma; Juan D. Bolañosb

2010-01-01

308

Étude de la transition entre le gaz atomique et le gaz moléculaire dans deux cirrus de la boucle céleste nord  

NASA Astrophysics Data System (ADS)

The infrared (IR) cirrus clouds observed at high Galactic latitude are excellent candidates to study the transition between the atomic gas and the molecular gas. In this thesis, two potential sites of H2 formation have been discovered in the North Celestial Loop (l = 135°, b = 40°) through examining the far-IR-Hl ratio and looking for an excess over that expected from an atomic medium. I call these sites the Spider and Ursa Major fields. The comparison between the IR excess map and the 12CO (J - 1 - 0) data from the Five College Radio Astronomical Observatory (resolution = 45 arcsec) shows that the IR excess peaks do not coincide with the 12CO peaks. The absence of coincidence is explained by (i) a density too small to allow CO excitation, (ii) insufficient CO self-shielding or (iii) variations of the dust properties. The comparison between 12CO data and Hi data from the Dominion Radio Astrophysical Observatory (resolution = 1 arcmin) is in agreement with the models! that predict CO formation where large velocity shears and turbulence dissipation are observed. OH observations of 108 locations over the two diffuse clouds from the Green Bank Telescope (resolution = 7 arcmin) are analyzed. OH is a precursor molecule to CO and its formation requires H2. The coincidence between the OH emission peak and the IR excess peak indicates that OH could be a better tracer of H2 than CO in these low-density regions. 12CO (7 = 1-0) and 13CO (J = 1 -0) observations from the Institut de Radioastronomie Millimétrique and 12CO ( J = 2 - 1) observations from the James Clerk Maxwell Telescope (resolution = 20 arcsec) are analyzed on a small number of fields in both regions. Using a large velocity gradient model, we found smaller densities at the location of the IR excess peak while self-shielding should be efficient given the computed column densities.

Barriault, Léo

2010-11-01

309

Modelo Juan XXIII, Santiago de los Caballeros, República Dominicana: Una asociación entre el gobierno y la sociedad civil  

Microsoft Academic Search

El presente trabajo describe el Modelo Juan XXIII: modelo establecido en un área urbana, con una historia de fuerte movilización comunitaria, una presencia institucional favorecedora del liderazgo comunitario y la participación, y un gobierno experimentando una estrategia de descentralización de la salud pública. Indaga si este programa ha producido los resultados tangibles para los 70,000 habitantes de las 24 barrios

Uli Locher

2002-01-01

310

Una nota sobre la sostenibilidad fiscal y el nexo entre los ingresos y gastos del Gobierno Colombiano  

Microsoft Academic Search

En este trabajo se analiza empíricamente la sostenibilidad fiscal en Colombia a través de las técnicas de cointegración. En particular, usando los ingresos tributarios y los gastos primarios del gobierno nacional central para el período 1990Q1 a 2008Q4 (datos reales y ajustados por el ciclo económico), en el documento se examina si las cuentas fiscales del gobierno han sido sostenibles

Ignacio Lozano; Enrique Cabrera

2009-01-01

311

Étude et catégorisation de pratiques effectives entre professeurs et auxiliaires de vie scolaire (AVS) à l’école primaire  

Microsoft Academic Search

The law “for equal rights and opportunity, the participation and the citizenship of disabled persons”, dated February the eleventh, imposes to register all the students in their school district and to make it easy for disabled people to be schooled within the mainstream education system, as often as possible. School-life assistant or auxiliaire de vie scolaire (AVS) appear to aid

Marie Toullec-Théry; Isabelle Nédélec-Trohel

2008-01-01

312

Conhecimento sobre o molusco gigante africano Achatina fulica entre estudantes de uma escola pública na Região Metropolitana do Recife  

Microsoft Academic Search

Students' knowledge on the African giant mollusk Achatina fulica in a public school in the Recife metropolitan region. The African giant mollusk Achatina fulica Bowdich, 1822 was introduced into Brazil in 1988 as a substitute for the European escargot Helix sp. This action did not induce the expected results and the gastropod has become an invasive species according to records

Renata Manzi de Souza; Ângelo Giuseppe; Chaves Alves; Marcos Souto Alves

313

Tabaco, álcool e outras drogas entre adolescentes em Pelotas, Rio Grande do Sul, Brasil: uma perspectiva de gênero  

Microsoft Academic Search

This study assesses the relationship between gender and use of psychoactive substances (al- cohol, nicotine, and illicit drugs) by teenagers. In 2002, a cross-sectional study was carried out in the urban area of Pelotas, southern Brazil. Multi-stage sampling was used to obtain a sam- ple of adolescents, 15 to 18 years of age. Subjects were interviewed using a self-applied confiden-

Rogério Lessa Horta; Bernardo Lessa Horta; Ricardo Tavares Pinheiro; Blanca Morales; Marlene Neves Strey

2007-01-01

314

RELACION ENTRE LAS CARACTERISTICAS DEL PAISAJE URBANO Y LA COMUNIDAD DE AVES INTRODUCIDAS EN LA CIUDAD DE VALENCIA (ESPAÑA)  

Microsoft Academic Search

SUMMARY.—Relationships between the characteristics of the urban landscape and the introduced bird community in the city of Valencia (Spain). Aims: We describe the community of introduced birds in the city of Valencia and the relationships between this community and the characteristics of the urban landscape at two spatial scales. Location: The study was carried out in the urban and rural

Enrique MURGUI; Anna VALENTÍN

2003-01-01

315

Avaliação das Habilidades Motoras Fundamentais de Crianças com Idades entre Nove e Doze Anos Praticantes de Futebol  

Microsoft Academic Search

The mature stage of the fundamental motor skills is indispensable to the learning of the specific sporting movement; therefore we present the relevance of the development of these skills in order to facilitate the learning process of the soccer fundamentals. The aim of this study was to verify the stages in which the fundamental motor skills were in fifteen male

AUGUSTO MOURA DE OLIVEIRA; JOAQUIM MARTINS JUNIOR

316

Aplicação de geotecnologias em correlações entre solos, geomofologia, geologia e vegetação nativa no Distrito Federal, DF1  

Microsoft Academic Search

An increase on population growth showed at Distrito Federal (DF) has promoted indiscriminated uses and occupations of their lands. To evaluate actual environmental situation, it's necessary to update and to detail disponible natural resources maps, mainly soils. Then, the objective for this work was to study the correlations within soils, geomorphology, geology and native vegetation and to detail disponible soil

Marilusa Pinto Coelho Lacerda; Inara Oliveira Barbosa; Paulo Roberto Meneses; José Wilson Correia Rosa; Henrique Laccer Roig

317

ESTABELECENDO PONTES ENTRE O OCIDENTE E O ORIENTE: UM CONTRIBUTO DA PERSPECTIVA BUDISTA NA EDUCAÇÃO PARA A SUSTENTABILIDADE  

Microsoft Academic Search

Dialogue among cultures is a main characteristic on the knowledge construction in the 21st century societies. In this document, following a tradition started around thirty years ago, we try a conversation between western science and eastern Mahayana Buddhist school. The goal of this conversation is to find what contribute this philosophical tradition may give to the development of sustained societies

Orlando Figueiredo; Escola Secundária de Peniche

2006-01-01

318

Entre le zero et l'infini...l'environnement (Between Zero and the Infinite...the Environment).  

ERIC Educational Resources Information Center

Envisages the environment as that which surrounds, conditions, opposes, and allows one to understand, identify, and attain a series of objectives. The relationship of this understanding of environment to second language learning is explored, with particular emphasis on recent methodologies that see language as a culture's mode of expression. (AMH)

Cortes, Jacques

1982-01-01

319

Gel conducteur pour la simulation électrique des tissus humains entre 50 Hz et 500 kHz  

Microsoft Academic Search

Different kind of phantoms have been proposed as physical and experimental ways for the simulation of systems using electromagnetic fields. This article presents a gelatine phantom for electromagnetic modelisation of human tissues in order to characterise the electromagnetic low frequency interferences with pacemaker. Electrical properties of different samples of gelatine, with or without adding, have been characterised. The electrical conductivity

C Goeury; A Hedjiedj; M Nadi

2001-01-01

320

Relación entre las características sociodemográficas y la concentración de flúor en el agua con el grado de fluorosis dental  

Microsoft Academic Search

in the water consumed by the 5-11 year-old school population in the city of Manizales, Colombia. Materials and method: This descriptive study administered 143 surveys to the parents of the school children that presented dental fluorosis, with the aim to collect socio-demographic information. The fluorine concentration in drinking water was estimated by means of the analysis of water samples taken

Olga Patricia; López Soto; Ana María; Naranjo Mejía; Dora Cardona Rivas; Hernán Parra Sánchez; Diego Fernando Endo González; Mónica Toro Gámez; Andrea Arias Hoyos; Paula Tatiana; Cadavid Naranjo

2005-01-01

321

Estudi de la dependéncia energética de les diferéncies entre jets de quarks i gluons utilitzant el detector DELPHI de LEP  

NASA Astrophysics Data System (ADS)

Three jet events arising from decays of the Z^0 boson, collected by the DELPHI detector at LEP, were used to measure differences in the properties of quark and gluon jet fragmentation. Gluon jets were anti-tagged in bbar{b}g events, by identifiying b quark jets with high purities. Unbiased quark jets came from events qbar{q}? with two jets plus one photon. A comparison of quark and gluon jet properties in different energy ranges was performed for the first time and within the same detector. The average value of the ratio of the mean charged multiplicities of gluon and quark jets was measured to be [ 1.232 ± 0.026 ({esta.}) ± 0.018 ({sist.}) ] where the fraction of b-quark initiates jets was 11% and the Durham jet finding algorithm has been used for the selection of three jet events. In agreement with QCD an increase of this ratio with energy was observed at a 3sigma level. A further dependence of this ratio related with the angular acceptance of the algorithm used to reconstruct jets was also measured. Gluon jets have a broader energy and particle flow around its jet axis than quark jets of equivalent energy. The string effect has been observed in fully symmetric three-jet events. The ratio R_? of the charged particles flow in the qbar{q} inter-jet region of the qbar{q}g and qbar{q}? samples was measured in agreement with the perturbative QCD expectation [ frac{(N_{qq})_{qbar{q}g}}{(N_{qq})_{qbar{q}?}} = 0.058 ± 0.06 ({stat.+sist.}) ] The dependence of the mean charged multiplicity on the hadronic center-of-mass energy was analysed in photon plus n-jet events. A value for

Garcia, S. Marti i.

1995-11-01

322

Optimisation de l'émission du continuum femtoseconde de lumière blanche entre 600 nm et 800 nm  

NASA Astrophysics Data System (ADS)

Un dispositif de spectroscopie avec résolution du temps de vol des photons en milieu diffus a été développé. Celui-ci repose sur l'utilisation d'un continuum de lumière blanche généré par focalisation d'un laser amplifié (830 nm, 1 kHz, 0.5 W, 170 fs) dans de l'eau déminéralisée. Afin d'optimiser spectralement et en puissance la source blanche sur la fenêtre spectrale 600 800 nm, une étude de la mise en forme spatio-temporelle avant autofocalisation de l'impulsion laser par le milieu a été menée. Cette mise en forme est effectuée de manière spatiale en changeant la focale de la lentille de focalisation et de manière temporelle en changeant le taux de compression de l'impulsion. L'étude montre que le cône de lumière émise possède plus de puissance dans la fenêtre spectrale d'intérêt pour des focales longues. Sur la fenêtre 600-800 nm, le rendement énergétique intégré varie de 5%, avec une focalef=6cm, à 15%, avec une focale f = 30 cm. La mise en forme temporelle montre des effets similaires avec les mêmes ordres de grandeur.

Ramstein, S.; Mottin, S.

2005-06-01

323

Relación entre lípidos séricos y estado de las vitaminas C y E como antioxidantes en adultos mayores venezolanos  

Microsoft Academic Search

RESUMEN. En el envejecimiento se observa tendencia a hiperlipidemias, cambios en la distribución de lipoproteínas y una declinación del sistema de defensa antioxidante del organismo. El objetivo de este estudio fue relacionar concentraciones séricas de colesterol total, fracciones, triglicéridos y Vitaminas C y E. Se evaluaron 61 adultos mayores de 60 años de edad, de enero-marzo, 2006. Se diagnosticó estado

Lesbia Meertens; Gloria Naddaf; Adelmo Rodríguez

2008-01-01

324

Observation du Couplage Entre les Diffusions Raman et Brillouin Stimulees (Observation of Coupling between Stimulated Raman and Brillouin Diffusion).  

National Technical Information Service (NTIS)

The Stokes and anti-Stokes components of stimulated Raman diffusion are investigated. The frequencies of these components are symmetric to the fundamental frequency of the laser, and their frequency fluctuations are a function of the density and electroni...

C. Labaune H. A. Baldis S. D. Baton T. Jalinaud D. Pesme

1991-01-01

325

Comparaison entre calculs de vuln\\\\'erabilit\\\\'e sismique et propri\\\\'et\\\\'es dynamiques mesur\\\\'ees  

Microsoft Academic Search

Large-scale seismic vulnerability assessment methods use simplified formulas and curves, often without providing uncertainties. They are seldom compared to experimental data. Therefore, we recorded ambient vibrations and estimated modal parameters (resonance frequencies, modal shapes and damping) of 60 buildings in Grenoble (France) of various types (masonry and reinforced concrete). The knowledge of resonance frequencies in the linear domain is essential

Clotaire Michel; Philippe Guéguen; Pierre-Yves Bard

2007-01-01

326

Mortalidade materna: um estudo dos níveis e das causas de óbitos no México e no Brasil entre 2000 e 2004  

Microsoft Academic Search

A mortalidade materna se apresenta como um grave problema social e de saúde pública, representando um importante indicador para avaliar as condições de assistência à saúde feminina. A preocupação com as mortes maternas está relacionada principalmente às repercussões sociais e econômicas que a morte de uma mulher acarreta para as famílias. Isto porque as mulheres assumem atribuições centrais na organização

Ana Paula Belon

327

Corrélation entre la résistance au poinconnement sur ballast et les caractéristiques mécaniques des membranes d'étanchéité  

Microsoft Academic Search

Résumé  Le succès du Colloque de Liège organisé en juin 1977 avec le concours de la RILEM, a réuni plus de 300 participants st a montré\\u000a l'intérêt suscité par l'utilisation des membranes en matières plastiques et caoutchoucs dans la recherche des solutions d'étanchéité\\u000a des grandes surfaces.\\u000a \\u000a Pour opérer le choix objectif d'une membrane afin de solutionner un problème posé, il convient

J. M. Rigo; K. Gamski

1978-01-01

328

Impact des conditions de transmission sur la qualité des échanges d'information entre véhicules en environnement urbain réel  

Microsoft Academic Search

RÉSUMÉ. Dans la plupart des simulations de réseaux ad'hoc, la couche physique est considérée de façon très simple. En outre, le routage de l'information est effectué en cherchant à minimiser uniquement le nombre de sauts ou le temps de transfert de l'information. Dans cet article, les auteurs présentent deux contributions. L'une consiste à considérer un modèle de propagation 3D prenant

Rodolphe VAUZELLE; Wassim HAMIDOUCHE; Anne Marie; Yannis POUSSET

2009-01-01

329

Changements organisationnels et évolution du vécu au travail : une comparaison entre secteur privé et fonction publique d'Etat  

Microsoft Academic Search

Au moyen du dispositif d'enquêtes couplées COI, nous avons analysé les effets des changements organisationnels dans le secteur privé et la fonction publique d'Etat, sur des indicateurs d'intensification du travail, d'évolution des compétences et de variation de l'implication des salariés. Les changements organisationnels sont plus intenses dans la fonction publique d'Etat que dans le secteur privé, confirmant l'importance des modifications

Maëlezig Bigi; Nathalie Greenan; Sylvie Hamon-Cholet; Joseph Lanfranchi

2012-01-01

330

Nuevos datos para un viejo debate: Los vínculos entre ferrocarriles e industrialización en Chile y México (1860-1950)  

Microsoft Academic Search

Since the 19th century, the specialization in and export of basic products in Latin America has not been incompatible with the creation of manufacturing industry; moreover, the path towards industrialization depended on the kind of infrastructure demanded by primary goods-exporting activity. In such an effort, the railroad was crucial,not only as a means of transporting basic products, but also as

Guillermo Guajardo

1998-01-01

331

Perfi l dos casos de meningite internados no Hospital Materno Infantil de Marília, São Paulo, entre 2000 e 2005  

Microsoft Academic Search

Objective: To analyze the epidemiologic profi le of me- ningitis in children admitted to the Maternal and Child Hospital of Marília, São Paulo, Brazil, after the introduction of Haemophilus infl uenzae type b vaccine. Methods: This analytical, descriptive and retrospective study enrolled patients from one month to 15 years old, admitted to the hospital with meningitis between Janu- ary\\/2000 to

Fausto Flor Carvalho; André Carvalho Kreuz; Danilo Gomes de Carvalho; Marcelo José Pádua

332

Diferencias entre el control clínico y ambulatorio de la hipertensión arterial en pacientes muy ancianos. Proyecto CARDIORISC–MAPAPRES  

Microsoft Academic Search

Background and objectiveHypertension is highly prevalent in the very elderly. We studied control rates of hypertension according to clinic blood pressure (BP) and ambulatory BP monitoring (ABPM) in treated hypertensives aged ?80 years.

José L. Llisterri; Francisco J. Alonso; Manuel Gorostidi; Cristina Sierra; Alejandro de La Sierra; José R. Banegas; Julián Segura; Javier Sobrino; Juan J. De La Cruz; Felipe Madruga; Pedro Aranda; Josep Redon; Luis M. Ruilope

2009-01-01

333

Comportement des consommateurs dans l'espace metropolitain: arbitrage entre centre-ville et en peripheries commerciales  

Microsoft Academic Search

L'objet de cette communication est d'analyser les comportements des consommateurs en matiere d'achat de biens et services au sein des metropoles urbaines. Les comportements de consommation conduisent a des deplacements qui peuvent etre analyses sous l'angle de l'utilisation de l'espace urbain, des distances parcourues et des preferences individuelles. Comment les consommateurs combinent-ils leurs deplacements journaliers, l'information dont ils disposent et

P.-Y. Leo; J. Philippe

2000-01-01

334

La ecología espacial como punto de encuentro entre la ecología animal y vegetal. Modelos espacialmente explícitos de dispersión endozoócora  

Microsoft Academic Search

Spatial ecology as a crossroad for animal and plant ecology. An example using spatially explicit models of endozoochorou s seed dispersal. In this article, we use seed-dispersal systems to exemplify the importance of spatial ecology for the study of plant -animal interactions. The study of seed-dispersal systems has been traditionally biased towards their plant component, with a relative disregard for

L. Santamaría; A. R. Larrinaga; A. Arceiz; J. Rodríguez Pérez

335

El Tzetz o Bledo (Amaranto): Una Planta Alimenticia de Origen Mesoamericano que Tiene Muchas Proteinas pero que se Esta Olvidando (Tzetz or Wild Amaranth (Amaranthus deulis): An Edible Mesoamerican Plant of High Protein but Forgotten).  

National Technical Information Service (NTIS)

The booklet discusses the use and history of the wild amaranth. Methods of cultivation and cooking recipes are given for the three types of wild amaranth. Suggestions for further research are also made.

1978-01-01

336

Analysis of Two in Planta Expressed LysM Effector Homologs from the Fungus Mycosphaerella graminicola Reveals Novel Functional Properties and Varying Contributions to Virulence on Wheat1[W][OA  

PubMed Central

Secreted effector proteins enable plant pathogenic fungi to manipulate host defenses for successful infection. Mycosphaerella graminicola causes Septoria tritici blotch disease of wheat (Triticum aestivum) leaves. Leaf infection involves a long (approximately 7 d) period of symptomless intercellular colonization prior to the appearance of necrotic disease lesions. Therefore, M. graminicola is considered as a hemibiotrophic (or necrotrophic) pathogen. Here, we describe the molecular and functional characterization of M. graminicola homologs of Ecp6 (for extracellular protein 6), the Lysin (LysM) domain-containing effector from the biotrophic tomato (Solanum lycopersicum) leaf mold fungus Cladosporium fulvum, which interferes with chitin-triggered immunity in plants. Three LysM effector homologs are present in the M. graminicola genome, referred to as Mg3LysM, Mg1LysM, and MgxLysM. Mg3LysM and Mg1LysM genes were strongly transcriptionally up-regulated specifically during symptomless leaf infection. Both proteins bind chitin; however, only Mg3LysM blocked the elicitation of chitin-induced plant defenses. In contrast to C. fulvum Ecp6, both Mg1LysM and Mg3LysM also protected fungal hyphae against plant-derived hydrolytic enzymes, and both genes show significantly more nucleotide polymorphism giving rise to nonsynonymous amino acid changes. While Mg1LysM deletion mutant strains of M. graminicola were fully pathogenic toward wheat leaves, Mg3LysM mutant strains were severely impaired in leaf colonization, did not trigger lesion formation, and were unable to undergo asexual sporulation. This virulence defect correlated with more rapid and pronounced expression of wheat defense genes during the symptomless phase of leaf colonization. These data highlight different functions for MgLysM effector homologs during plant infection, including novel activities that distinguish these proteins from C. fulvum Ecp6.

Marshall, Rosalind; Kombrink, Anja; Motteram, Juliet; Loza-Reyes, Elisa; Lucas, John; Hammond-Kosack, Kim E.; Thomma, Bart P.H.J.; Rudd, Jason J.

2011-01-01

337

EFFECT OF CALCIUM, BORON AND MOLYBDENUM ON PLANT GROWTH AND BRACT PIGMENTATION IN POINSETTIA EFECTO DEL CALCIO, BORO Y MOLIBDENO EN EL CRECIMIENTO DE PLANTA Y PIGMENTACIÓN DE BRÁCTEAS EN NOCHEBUENA  

Microsoft Academic Search

SUMMARY Foliar sprays of Ca (300, 400, and 500 mg L -1 ), B (0.2, 0.5, and 0.8 mg L -1 ), Mo (0.3, 0.4, and 0.5 mg L -1 ), Ca + B (400 + 0.5 mg L -1 ), Ca + Mo (400 + 0.4 mg L -1 ), B + Mo (0.5 + 0.4 mg L -1

Juan Ayala Arreola; Ana M; Castillo González; Luis A. Valdez Aguilar; Teresa Colinas León; Joel Pineda Pineda; Edilberto Avitia García

338

454-pyrosequencing of Coffea arabica leaves infected by the rust fungus Hemileia vastatrix reveals in planta-expressed pathogen-secreted proteins and plant functions in a late compatible plant-rust interaction.  

PubMed

Coffee (Coffea arabica L.), one of the key export and cash crops in tropical and subtropical countries, suffers severe losses from the rust fungus Hemileia vastatrix. The transcriptome of H. vastatrix was analysed during a compatible interaction with coffee to obtain an exhaustive repertoire of the genes expressed during infection and to identify potential effector genes. Large-scale sequencing (454-GS-FLEX Titanium) of mixed coffee and rust cDNAs obtained from 21-day rust-infected leaves generated 352 146 sequences which assembled into 22 774 contigs. In the absence of any reference genomic sequences for Coffea or Hemileia, specific trinucleotide frequencies within expressed sequence tags (ESTs) and blast homology against a set of dicots and basidiomycete genomes were used to distinguish pathogen from plant sequences. About 30% (6763) of the contigs were assigned to H. vastatrix and 61% (13 951) to C. arabica. The majority (60%) of the rust sequences did not show homology to any genomic database, indicating that they were potential novel fungal genes. In silico analyses of the 6763 H. vastatrix contigs predicted 382 secreted proteins and identified homologues of the flax rust haustorially expressed secreted proteins (HESPs) and bean rust transferred protein 1 (RTP1). These rust candidate effectors showed conserved amino-acid domains and conserved patterns of cysteine positions suggestive of conserved functions during infection of host plants. Quantitative reverse transcription-polymerase chain reaction profiling of selected rust genes revealed dynamic expression patterns during the time course of infection of coffee leaves. This study provides the first valuable genomic resource for the agriculturally important plant pathogen H. vastatrix and the first comprehensive C. arabica EST dataset. PMID:21726390

Fernandez, Diana; Tisserant, Emilie; Talhinhas, Pedro; Azinheira, Helena; Vieira, Ana; Petitot, Anne-Sophie; Loureiro, Andreia; Poulain, Julie; Da Silva, Corinne; Silva, Maria Do Céu; Duplessis, Sébastien

2012-01-01

339

Methodology for producing 100 tons of fuel peat for a cement plant test burn. Metodologia para producir 100 toneladas de turba combustible para una prueba de quema en uns planta de cemento  

SciTech Connect

As a part of the Agency for International Development-funded cooperative project between Los Alamos and Costa Rica, the burning characteristics of Costa Rican peat were to be tested in an application. The cement plant owned by Industria National de Cemento in Cartago has a capability to handle solid fuel and was chosen for the burn demonstration. The Jungle No. 1 Peat Deposit near El Cairo was chosen as the site of the peat excavation. This peat production methodology study covers project site selection, installation of an access road and clearing of the jungle vegetation, removal of an upper layer of organic peat, excavation of fuel-grade peat, transport of the peat to the drying site, and drying and stockpiling of the finished product. As of this date the peat removal for the demonstration project has been started, and a description of the operation is included as an appendix to this paper. 10 figs.

Allen, A.B.; Malavassi, L.; Ramirez, O.; Thayer, G. (Allen (Andrew), Plymouth, NC (USA); RECOPE, San Jose (Costa Rica); Los Alamos National Lab., NM (USA))

1989-05-01

340

Avaliacao da eficacia de chas caseiros de plantas medicinais utilizados no tratamento da diarreia infantil. (Evaluation of home-made teas efficiency from medicinal plants used on childish diarrhea treatment).  

National Technical Information Service (NTIS)

The objective of this work is to verify whether the home-made teas form Brazilian plants, used for control of childish diarrhea have been efficient reaching the composition recommended by World Health Organizations (WHO). This work has been carried out us...

M. M. Pinto M. J. S. F. Silva C. Vilhena Schayer Sabino A. M. Amaral

1996-01-01

341

Extratos de plantas no controle de Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae) em laboratório Plant extracts in control of Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae) in laboratory  

Microsoft Academic Search

Plant extracts were studied to evaluate its efficiency in the control of Rhipicephalus (Boophilus) microplus (Canestrini, 1887) in laboratory. Engorged female ticks were collected from the cattle, kept in Petri dishes. Organic alcoholic extracts 2% (weight\\/volume) were used: seeds of Annona muricata L. (Annonaceae) (soursop); flowers of Syzygium malaccensis (L.) (Myrtaceae) (iamb), leaves of Cymbopogon citratus (DC.) Stapf (Poaceae) (holy

Ellen Carine; Neves Valente; Leilianne Alves de Souza; Nivia da Silva Dias

2009-01-01

342

Visualization of the Interaction between the Precursors of VPg, the Viral Protein Linked to the Genome of Turnip Mosaic Virus, and the Translation Eukaryotic Initiation Factor iso 4E In Planta?  

PubMed Central

The RNA genome of Turnip mosaic virus is covalently linked at its 5? end to a viral protein known as VPg. This protein binds to the translation eukaryotic initiation factor iso 4E [eIF(iso)4E]. This interaction has been shown to be important for virus infection, although its exact biological function(s) has not been elucidated. In this study, we investigated the subcellular site of the VPg-eIF(iso)4E interaction using bimolecular fluorescence complementation (BiFC). As a first step, eIF(iso)4E, 6K-VPg-Pro, and VPg-Pro were expressed as full-length green fluorescent protein (GFP) fusions in Nicotiana benthamiana, and their subcellular localizations were visualized by confocal microscopy. eIF(iso)4E was predominantly associated with the endoplasmic reticulum (ER), and VPg-Pro was observed in the nucleus and possibly the nucleolus, while 6K-VPg-Pro-GFP induced the formation of cytoplasmic vesicles budding from the ER. In BiFC experiments, reconstituted green fluorescence was observed throughout the nucleus, with a preferential accumulation in subnuclear structures when the GFP split fragments were fused to VPg-Pro and eIF(iso)4E. On the other hand, the interaction of 6K-VPg-Pro with eIF(iso)4E was observed in cytoplasmic vesicles embedded in the ER. These data suggest that the association of VPg with the translation factor might be needed for two different functions, depending of the VPg precursor involved in the interaction. VPg-Pro interaction with eIF(iso)4E may be involved in perturbing normal cellular functions, while 6K-VPg-Pro interaction with the translation factor may be needed for viral RNA translation and/or replication.

Beauchemin, Chantal; Boutet, Nathalie; Laliberte, Jean-Francois

2007-01-01

343

COMUNIDADES DE PLANTAS ACUÁTICAS EN LAGUNAS DE LOS PÁRAMOS DEL NORTE Y SUR DEL ECUADOR Aquatic plant communities in lakes of the Páramos of north and south of Ecuador  

Microsoft Academic Search

A study on aquatic plant distribution and its relationship with environmental factors was carried out in 16 high Andean lakes (3100-3900 m a s l). Nine lakes were located near to the northern border of Ecuador and seven located 600 km further south in the Podocarpus National Park. The purpose of the study was to identify differences in the floristic

ESTEBAN TERNEUS

344

Interplay of light and temperature during the in planta modulation of C4 phosphoenolpyruvate carboxylase from the leaves of Amaranthus hypochondriacus L.: diurnal and seasonal effects manifested at molecular levels  

PubMed Central

The interactive effects of light and temperature on C4 phosphoenolpyruvate carboxylase (PEPC) were examined both in vivo and in situ using the leaves of Amaranthus hypochondriacus collected at different times during a day and in each month during the year. The maximum activity of PEPC, least inhibition by malate, and highest activation by glucose-6-phosphate were at 15.00?h during a typical day, in all the months. This peak was preceded by maximum ambient light but coincided with high temperature in the field. The highest magnitude in such responses was in the summer (e.g. May) and least in the winter (e.g. December). Light appeared to dominate in modulating the PEPC catalytic activity, whereas temperature had a strong influence on the regulatory properties, suggesting interesting molecular interactions. The molecular mechanisms involved in such interactive effects were determined by examining the PEPC protein/phosphorylation/mRNA levels. A marked diurnal rhythm could be seen in the PEPC protein levels and phosphorylation status during May (summer month). In contrast, only the phosphorylation status increased during the day in December (winter month). The mRNA peaks were not as strong as those of phosphorylation. Thus, the phosphorylation status and the protein levels of PEPC were crucial in modulating the daily and seasonal patterns in C4 leaves in situ. This is the first detailed study on the diurnal as well as seasonal patterns in PEPC activity, its regulatory properties, protein levels, phosphorylation status, and mRNA levels, in relation to light and temperature intensities in the field.

Avasthi, Uday K.; Izui, Katsura; Raghavendra, Agepati S.

2011-01-01

345

Detección del Virus Mosaico Amarillo de la Calabaza Zucchini (ZYMV) y su Coinfección con otros Virus en Cucurbitáceas Cultivadas y Plantas Silvestres en el Valle del Fuerte, Sinaloa, México  

Microsoft Academic Search

Viral diseases are the main limiting factor for cucurbit production in El Fuerte Valley, Sinaloa, Mexico. The objective of this study was to detect Zucchini yellows mosaic virus (ZYWV), Watermelon mosaic virus (WMV), Papaya ring spot virus (PRSV-W), and Cucumber mosaic virus (CMV) using ELISA and RT-PCR procedures. ZYMV and the mixture ZYMV + PRSV-W predominated during the month of

Rubén Félix-Gastélum; Marco Antonio Magallanes-Tapia; Jesús Méndez-Lozano; Hervé Huet; José Ángel Trigueros-Salmerón; Rosa María Longoria-Espinoza

2007-01-01

346

Medicinal ethnobotany in Huacareta (Chuquisaca, Bolivia)  

PubMed Central

Background The aim of this study was to document the types of diseases treated by the use of medicinal plants, their main applications and also to have a report of the major diseases treated at the Hospital of San Pablo de Huacareta (Chuquisaca Bolivia). Methods We conducted semi-structured interviews on the use medicinal plants with 10 local informants, and categorized the kinds of diseases treated by traditional medicine. We obtained reports of cases treated at the Hospital of Huacareta in order to compare the use frequency of traditional medicine and allopathic medicine for the treatment of recurrent diseases in the area. Results Our survey identified 258 traditional medicine uses, spanning a total of 13 diseases categories and including 91 native and exotic plant species and one unidentified sample plant type. Gastrointestinal disorders (55%) were most frequently treated with medicinal plants, followed by afflictions of the musculoskeletal system (25%) and dermatological disorders (24%). Hospital information indicates that the most common diseases are acute respiratory infections (47%) and acute diarrheal diseases (37%). The herbal remedies were mostly used in the form of teas and decoctions. The informants used mainly native plant species, although exotic species has been introduced to the pharmacopoeia. Conclusions The treatment of gastrointestinal disorders is the primary objective of the medical ethnobotany of the inhabitants of Huacareta, while respiratory system diseases are mostly treated in the hospital. Looking at the data from the Hospital records we can infer that gastrointestinal disorders are among the most common diseases in the study area. For most respondents, traditional medicine is a reliable choice for the care of their illnesses. However, the preference of the population for either traditional medicine or allopathic medicine needs to be clarified in future comparative studies to obtain more convincing results. The results presented can be used as a base for subsequent work related to traditional medicine and its contribution to allopathic medicine in San Pablo de Huacareta. Resumen Introducción El objetivo del presente estudio fue documentar los tipos de enfermedades tratadas mediante el uso de plantas medicinales, sus aplicaciones principales y también tener un reporte de las enfermedades mayormente atendidas en el Hospital de San Pablo de Huacareta (Chuquisaca, Bolivia). Métodos Se realizaron encuestas semiestructuradas a 10 informantes locales anotando los usos atribuidos a sus plantas medicinales, se agruparon las plantas por categorías de enfermedades tratadas en la medicina tradicional. Se obtuvieron reportes de casos tratados en el Hospital de Huacareta para poder relacionar el tratamiento de enfermedades recurrentes en la zona entre la medicina tradicional y la medicina occidental. Resultados Se reportaron 91 especies nativas y exóticas, además de un espécimen indeterminado exótico que intervienen en un total de 258 aplicaciones medicinales, las cuales son empleadas en un total de 13 categorías de enfermedades. Los desórdenes gastrointestinales (55%) son mayormente tratados mediante plantas medicinales, seguidas de las afecciones al sistema esqueleto-muscular (25%) y enfermedades dermatológicas (24%). La información del Hospital indica que las enfermedades más frecuentes son Infecciones Respiratorias Agudas (47%) y Enfermedades Diarreicas Agudas (37%). Los remedios vegetales se emplean en forma de infusiones y cocciones principalmente. Se emplean mayormente plantas nativas, también se introdujo en la farmacopea médica el uso de plantas exóticas al lugar. Conclusiones El tratamiento de trastornos gastrointestinales constituye el objetivo primordial de la etnobotánica médica de los habitantes de Huacareta, las enfermedades del sistema respiratorio, son mayormente tratadas en el Hospital. Observando los datos del libro de consultas del Hospital, se puede inferir que los desórdenes gastrointestinales

2012-01-01

347

Distance Education Research.  

ERIC Educational Resources Information Center

Reviews six papers from the Open University Distance Education Research Group which cover the following topics: the credibility of distance education, admission systems, distance methods in adult basic education, the Universidad Estatal a Distancia (Costa Rica), Radio Ecca (Canary Islands), and the Open University (Great Britain). (EAO)

Curran, Chris

1983-01-01

348

Analysis of the Use of Twitter as a Learning Strategy in Master's Studies  

ERIC Educational Resources Information Center

The present study analyses the use of Twitter in the course Social Media and Digital Learning, taught as part of a master's programme at Universidad Nacional de Educacion a Distancia (Spain). The main purpose of the use of this resource was to develop a learning community. This was implemented through the micro design of activities. A mixed…

Feliz, Tiberio; Ricoy, Carmen; Feliz, Sálvora

2013-01-01

349

pserra@dii.uchile.cl  

Microsoft Academic Search

Desde su privatización, las empresas de telecomunicaciones han aumentado la cobertura de los servicios, así como su eficiencia interna. Luego de la desregulación de los servicios de larga distancia, las tarifas cayeron fuertemente y algo similar ocurrió con telefonía móvil, después de que el número de operadores aumentara de dos a cuatro. Sin embargo, la regulación insuficiente de los cargos

Ronald Fischer; Pablo Serra

2002-01-01

350

Some Social Implications of Distance Education.  

ERIC Educational Resources Information Center

Social implications of distance education at the university level are considered, based primarily on the case of La Universidad Estatal a Distancia (UNED) of Costa Rica. UNED, which is Costa Rica's attempt to implement Great Britain's open university philosophy of education, was developed in response to the following needs: to provide…

Borden, George A.

351

Internet, Multimedia and Virtual Laboratories in a 'Third World' Environment.  

ERIC Educational Resources Information Center

Describes the development of low-cost multimedia courses and materials for use on the Internet, as well as virtual laboratories, at the Universidad Estatal a Distancia (Costa Rica). Explains how simultaneous production of traditional printed materials and online courses, outsourcing, and the use of HTML and Java can reduce costs for developing…

Monge-Najera, Julian Antonio; Rivas Rossi, Marta; Mendez-Estrada, Victor Hugo

2001-01-01

352

A ARBITRAGEM COMO FORMA DE RESOLUÇÃO DE CONFLITOS ENTRE OS USUÁRIOS DO SECOND LIFE. ARBITRATION AS A MEANS OF RESOLVING CONFLICTS BETWEEN USERS OF SECOND L IFE  

Microsoft Academic Search

This article intends to register an analysis of the virtual environm ent of Second Life, for the forms of conflict resolution. But the idea is to start a discussion in the face of virtual environments that are emerging about virtual well, applicability of law in the face of questions concerning the network. Despite no longer mention the proportionality of the

Karla Cristina da Costa; Silva Matos Ferragi

353

Análise da expansão de área agrícola do Município de Lucas do Rio Verde - GO entre os anos de 1986 e 2007  

Microsoft Academic Search

Conversions of natural landscapes to croplands can be evaluated by remote sensing techniques, more specifically by change detection methods and by multitemporal data. These are essential sources of inf ormation to understand land use and land cover dynamics. Th is work has arisen from needing to compare differen ces in land cover using two Landsat \\/TM datasets throughout the time

Silvia Cristina de Jesus

354

Associação entre aves e flores de duas espécies de árvores do gênero Erythrina (Fabaceae) na Mata Atlântica do sudeste do Brasil  

Microsoft Academic Search

Association between birds and flowers of two species of trees of the genus Erythrina (Fabaceae) in the Atlantic forest of southeastern Brazil. Flowers are considered important resources in the diet of birds during the dry season. We studied the interaction between birds and two species of the trees of genus Erythrina (E. falcata and E. verna) at four localities in

Ricardo Parrini; Marcos A. Raposo

2008-01-01

355

Se identifica una relación entre la falta de exámenes de detección y una gran parte de los casos de cáncer de seno en la etapa avanzada  

Cancer.gov

Los autores de un estudio publicado el 20 de octubre de 2004 en la revista Journal of the National Cancer Institute1? declaran que las dos prioridades principales del sistema de salud deben ser aumentar el porcentaje de exámenes de mamografía e invertir en investigaciones que mejoren la tecnología para detectar el cáncer de seno.

356

Un tournant dans l'histoire technique de la sidérurgie : la création de l'Irsid. Compétition et collaboration entre l'Etat et l'industrie  

Microsoft Academic Search

[eng] Abstract There were no profesionnal center of technological researches in the French steel industry before World War two. This central laboratory («l'Irsid : Institut de la recherche sidérurgique») was imagined by Jean Rist in 1943 and created by Henri Malcor in 1946. This is a business initiative. Mining enginers from National School of Mining, those specializing in high grade

Philippe Mioche

1989-01-01

357

Relación entre el potencial zeta y la deposición en el lavado de impurezas sólidas sobre tejidos de algodón, poliéster y poliéster-algodón tratados con diferentes aprestos  

Microsoft Academic Search

Deposition of solid impurities of textile substrates, in washing, is due to different causes which can be of mechanical, chemicai, electrical or adsorption origin.\\u000aThe electrical phenomenon is studied by the electrokinetic potential or zeta potential. This potential depends on the fibre surface and the polar medium in which in steeped. For this reason, we used cotton, polyester, and polyester-cotton

Francisco Javier Carrión Fité; José Ribé Pons

1970-01-01

358

Avaliando a habitação: relações entre qualidade, projeto e avaliação pós-ocupação em apartamentos1 Assessing housing quality: relationships between apartment quality, design, and post-occupancy evaluation  

Microsoft Academic Search

This article discusses a methodology for post-occupancy evaluation (POE) of apartment buildings for the middle class built in Ribeirão Preto, SP, after 2000, aiming at contributing for the establishment of effective feedback tools for this kind of projects. The goal of this POE application was to evaluate the quality of internal and collective spaces of those apartment buildings in an

Simone Barbosa Villa

359

Thriving Together: Connecting Rural School Improvement and Community Development = Prosperando juntos: La conexion entre el mejoramiento de la escuela rural y el desarrollo comunitario.  

ERIC Educational Resources Information Center

Available in English or Spanish, this resource guide aims to help rural schools and communities learn ways of supporting each other so that both can thrive. Background information and basic tools are provided for starting a joint school-community development effort. Chapters contain: (1) outline of the guide and statement of beliefs about…

Boethel, Martha

360

Nouvelles découvertes de vertébrés dévoniens en Amérique du Sud et leurs implications dans le contact entre le Gondwana et l'Euramérique.  

NASA Astrophysics Data System (ADS)

A new fossil fish fauna from western Venezuela provides the first South American Devonian record of antiarch and phyllolepid placoderms, and sarcopterygians including lungfishes, groups widely distributed on other continents. Endemic elements in the fish fauna indicate Gondwana affinities, and the age of the phyllolepid placoderm occurrence is consistent with a model of biotic dispersal between Gondwana and Euramerica near the Frasnian-Famennian boundary. A narrow marine barrier separating northern and southern landmasses is indicated, in contrast to the wide equatorial ocean for the Late Devonian postulated from palaeomagnetic data.

Young, Gavin C.; Moody, John M.; Casas, Jhonny E.

2000-12-01

361

Les relations universite-entreprise entre l'etat et le besoin (University-Business Relationships between the State and the Need).  

ERIC Educational Resources Information Center

A discussion of the role of government in supporting the relationship between business and higher education focuses on academic research and the economic and industrial value placed on it. The actual support provided by the private sector, roles of the three players, and major issues in the debate are examined. (MSE)

Leclerc, Michel

1991-01-01

362

ESTUDIO COMPARATIVO DEL BAJO PESO AL NACER, DEPRESION AL 1er MINUTO Y TERMINACION CESAREA ENTRE MADRES ADOLESCENTES Y LA POBLACION GENERAL  

Microsoft Academic Search

SUMMARY: Objective: to evaluate the characteristics of new born, Caesarean completion, establishing differences between adolescent mothers (10 to 19 years) and nonadolescent mothers (greater of 19 years). Methodology: retrospective design, comparative. Were reviewed the collected data of the Computer science System Perinatal of Hospital \\

Silvina Analía; Soledad Lezcano; Maria Selva Vallejos Arce; Hipólito Sodero

363

Relación entre saberes y prácticas culinarios con la conservación de la agrodiversidad. Estudio etnobotánico en el Parque Pereyra Iraola (Buenos Aires, Argentina)  

Microsoft Academic Search

The Park Pereyra Iraola, 10,200 hectares located in Buenos Aires Conurbano (peripheral localities to the city of Buenos Aires, capital of Argentina), constitutes the greater green lung of the area more densely populated in the country. At the moment, among the diverse ventures settled in the Park, 1200 of the hectares are devoted to approximately 100 gardens or \\

Elida Turco; Lucía Souilla; Ministerio de Asuntos

364

Le travail des hommes de la paix : le cas des relations entre Louis XIV et Leopold Ier de 1668 à 1673  

Microsoft Academic Search

[eng] Résumé The study of how the relations between France and the Emperor operated between 1668 and 1673 gives an example of the work put in by the personnel of faithful and clients who attended on the secretary of State for foreign affairs, Hugues de Lionne. The problems were how to pass on news and how to adapt oneself to

Philippe Romain

1986-01-01

365

Correlación entre la estructura de bandas y las propiedades físicas de óxidos cerámicos de estructura perovskita con metales de transición (I): Propiedades de conducción electrónica  

Microsoft Academic Search

En este artículo se revisa los principales modelos teóricos, que pretenden dar una explicación sobre las propiedades de con- ducción electrónica de óxidos cerámicos con estructura perovskita, que incluyen en la posición B metales de transición del primer período (Fe, Co, Ni, Mn), en conexión con su estructura de bandas y el carácter de sus electrones más externos, así como

L. SÁNCHEZ; J. R. JURADO

366

Hacia el Enlace entre la Estrategia Empresarial Mediante Modelos de Valor y el Software Mediante Modelos de Negocio: un Enfoque MDD  

Microsoft Academic Search

Uno de los objetivos del modelado de negocio es compren- der el funcionamiento de las empresas con el fin de aportar soluciones software de alto valor anadido. Estos modelos de negocio se ubican en diferentes perspec- tivas, desde aquellas mas cercanas a la estrategia del negocio, hasta las mas cercanas al software. A pesar de la importancia del modelado de

José Bocanegra; Antonio Ruiz-Cortés

367

ANÁLISIS DE CONTENIDO DE LAS PUBLICACIONES ESPAÑOLAS SOBRE RELACIONES VERTICALES ENTRE EMPRESAS \\/ CONTENT ANALYSIS OF SPANISH PUBLICATIONS ON VERTICAL RELATIONSHIPS AMONG ENTERPRISES  

Microsoft Academic Search

En los últimos años los investigadores han mostrado un creciente interés en las relaciones interorganizativas verticales, principalmente en la Cadena de Suministro. La ausencia de trabajos previos de revisión bibliográfica sobre este tema, que permitan plantear las cuestiones clave a estudiar en Gestión de la Cadena de Suministro, nos ha llevado a realizar un análisis de contenido de la investigación

M. T. Martínez Fernández; T Vallet Bellmunt; R. Barreda Tarrazona

2010-01-01

368

Relación entre el virus del papiloma humano y la amplificación del gen de la ciclina D1 en los carcinomas epidermoides de cabeza y cuello  

Microsoft Academic Search

Introduction: infection by oncogenic subtypes of human papillomavirus (HPV) and cyclin D1 gene (CCND1) amplification are frequent events in head and neck squa- mous cell carcinomas. The objective of this paper is to esta- blish the relationship between the presence of human papi- llomavirus (HPV) gene sequences and the development of CCND1 gene amplification in these tumours. Materials and methods:

J. P. Rodrigo Tapia; L. A. García González; I. Alvarez Alvarez; R. Cabanillas Farpón; C. Suárez Nieto; INVESTIGACIÓN CLÍNICA

2005-01-01

369

DIFERENCIAS EN LAS ESTADÍSTICAS DE JUEGO ENTRE BASES, ALEROS Y PÍVOTS EN BALONCESTO FEMENINO Differences between women's basketball guards, forwards and centres through game-related statistics  

Microsoft Academic Search

The aim of the present study was to analyze the differences in game-related statistics between basketball guards, forwards and centres from the WNBA League (professional league in fe- male basketball in USA, organized by the Women National Bas- ketball Association). The sample was gathered from the WNBA boxscores from the 2005 season (n= 215 games), selecting an amount of 75

Miguel Ángel Gómez Ruano; Alberto Lorenzo Calvo; Enrique Ortega Toro; Jaime Sampaio; Sergio-José Ibáñez Godoy

2007-01-01

370

RELACIÓN ENTRE ESTRATEGIAS DE CONTROL EN EL AMBIENTE FAMILIAR Y ESCOLAR Y PRÁCTICAS DE JUEGO EN NIÑOS, NIÑAS Y JÓVENES1  

Microsoft Academic Search

This article presents the analysis of relations between juvenile game practices and control strategies in family and school, as part of a larger study on game practices in the youth of Bogotá. Interviews of 155 participants between 10 to 17 years of age and their parents were analysed. Participants were classified in two groups according to their level of game

CLAUDIA CAYCEDO; ROCÍO GARCÍA; BLANCA PATRICIA BALLESTEROS; MÓNICA MARÍA NOVOA

371

Suivis temporels comparés de la structure thermique d'eaux côtières libanaises (Batroun) et françaises (Marseille) entre juin 1999 et octobre 2002  

NASA Astrophysics Data System (ADS)

Vertical temperature profiles were recorded from June 1999 to October 2002 (at least once a month) at two Mediterranean sites, in the eastern basin (Batroun, Lebanon; 0-100 m) and in the northwestern basin (Marseilles, France; 0-55 m). At the two sites, the thermal seasonal evolution and the thermocline time dynamics are quite identical. But in the Lebanese waters, at comparable water depths, temperatures are currently 4 to 5 °C higher than in the French waters, the thermocline is longer (more than 6 months), permanent and deeper (40-50 m) than in Marseilles (20-30 m). The latter frequently disappears in summer due to northwest winds inducing cold waters. This is principally due to differences in prevailing wind regimes at each site. Such evaluation, coupled with long-term observations of temporal evolution of coastal water at the regional level of the Mediterranean basins, will shed light on temperature regime fluctuations and their consequences in the context of global warming of the Mediterranean. To cite this article: M. Abboud-Abi Saab et al., C. R. Geoscience 336 (2004).

Abboud-Abi Saab, Marie; Romano, Jean-Claude; Bensoussan, Nathaniel; Fakhri, Milad

2004-11-01

372

RELAÇÕES ENTRE A CONCENTRAÇÃO DE ÍONS E A SALINIDADE DE ÁGUAS SUBTERRÂNEAS E SUPERFICIAIS, VISANDO À IRRIGAÇÃO, NO SERTÃO DE PERNAMBUCO  

Microsoft Academic Search

The objective of the study was to determine the relationship between the electrical conductivity of subsurface and surface water (ECw in dS\\/m at 25°C) and the ion concentration of Na +, Ca2+ + Mg2+ and C1- (in mmolc L -1 ). The study was based on 75 and 100 samples collected from subsurface and surface waters, respectively, in 33 counties

José Nunes Filho; Antonio Raimundo de Sous; Vital Artur de Lima; Berthyer Peixoto Lima

373

Le transfert de connaissances entre les mathematiques et les sciences. Une etude exploratoire aupres d'eleves de 4e secondaire  

Microsoft Academic Search

Au moment ou dans plusieurs pays on travaille a refondre les programmes d'etudes, tant au primaire qu'au secondaire, l'interet pour le transfert renait. Un des concepts fondamentaux en apprentissage consiste en l'habilete a reutiliser de facon consciente et efficace un acquis d'une situation a une autre situation. Cette recherche emane de preoccupations professionnelles au moment ou le chercheur etait enseignant

Ghislain Samson

2003-01-01

374

Difusión de nuevas tecnologías y estimación de la demanda de nuevos productos: un análisis comparativo entre Argentina y EE.UU  

Microsoft Academic Search

RESUMEN Este trabajo analiza, utilizando el modelo de Bass, la demanda de telefonía celular, acceso a Internet, y acceso a Internet por banda ancha en Argentina y en EE.UU. a fines de determinar los patrones de difusión de nuevas tecnologías. Los resultados indican que en EE.UU. la velocidad de difusión es mayor que en Argentina, y prevalece -a diferencia de

Viviana Weissmann

375

Auto-inflammation de substances explosives. Comparaison entre calcul analytique et numérique en vue d'une optimisation dans le domaine de la pyrotechnie  

Microsoft Academic Search

Self-ignition of energetic material was investigated in order to optimize safety in the field of pyrotechnic applications. Two approaches were used; the first one is relative to Frank-Kamenetskii stationary thermal explosion theory. The second approach consists of a choice of some numerical solutions of heat conduction equations in a non-stationary state. Comparison between these results was carried out in order

Philippe Gillard

1998-01-01

376

Interaction entre les défauts ponctuels créés, les parois de Bloch et les dislocations dans le nickel irradié aux électrons à basse température  

Microsoft Academic Search

INTERACTION BETWEEN POINT DEFECTS, BLOCH WALLS AND DISLOCATIONS, IN LOW-TEMPERATURE ELECTRON-IRRADIATED NICKELAfter irradiating a nickel sample at 29 K with 2 MeV electrons followed by an isochronal thermal treatment, one obtained :(a) a bulk elastic effect depending on the global concentration of point defects.(b) a reorientation effect of these defects and their interaction with Bloch walls.(c) a pinning of the

Par J. C. Soulie; C. Minier; J. Lauzier

1973-01-01

377

Correlations Entre Niveau de Conscience, E.E.G. Et Potentiels Evoques Chez l'Homme (Level of Consciousness, EEG and Evoked Potentials in Man).  

National Technical Information Service (NTIS)

A comparative study was made of the visual evoked response in some neurological conditions having in common a decrease of the level of consciousness with delta activity in the EEG, but differing in their origin (deep sleep, barbiturate narcosis, post-elec...

F. Corletto A. Gentilomo G. Rosadini G. F. Rossi J. Zattoni

1966-01-01

378

Entre didactique et pedagogie: Epistemologie de l'espace/temps strategique (Between Instruction and Pedagogie: The Epistemology of Strategic Time/Space).  

ERIC Educational Resources Information Center

Analyzes the components of teaching, envisioning a strategic moment when instruction and pedagogy merge. Examines the way in which transformations of knowledge could be represented according to recent trends in artificial intelligence. (DMM)

Tochon, Francois, V.

1991-01-01

379

Denomination et categorisation des modeles d'enseignement des langues: entre institution et pratique (Denomination and Categorization of Language Teaching Models: Between Institution and Practice).  

ERIC Educational Resources Information Center

The process and issues of labeling language program models is discussed insofar as it may affect the objectives, content, and method of instruction. The first section describes the origins, stated objectives, and implementation of a Neuchatel (Switzerland) school program integrating heritage language and culture into the school curriculum, noting…

Gajo, Laurent; Matthey, Marinette

1998-01-01

380

La microangiopathie du diabète. étude des relations entre les données de la biopsie cutanée, l'âge du malade, le type et la durée du diabète  

Microsoft Academic Search

Riassunto Il presente lavoro concerne lo studio dei rapporti tra la microangiopatia, valutata in base ai dati semi-quantitativi della biopsia cutanea (percentuale di capillari sanguigni che presentano un anello PAS-positivo periferico omogeneo), il tipo e la durata del diabete e l'età dei malati. Tale studio riguarda una casistica di 188 diabetici (54 con diabete chimico, 100 con diabete non insulinodipendente

Jean-Dominique Romani

1972-01-01

381

Relations structurales entre U 3O 8 et quelques fluorures mixtes de formules M2M' 3F 11, MM' 2F 7 et MM' 3F 10  

NASA Astrophysics Data System (ADS)

U 3O 8 oxide, as well as M2M' 3F 11, MM' 2F 7 and MM' 3F 10 fluorides, with M = Rb, Tl, Cs, NH 4 and M' = In, Lu, Yb, Tm, is described as the regular repetition according to the … A-A-A … sequence of identical and parallel sheets of edge-and corner-sharing M'F 7 or UO 7 pentagonal bipyramids and M'F 6 octahedra. M' and U atoms are systematically located at the lattice points of a pseudohexagonal network, but in the fluorides some of these lattice points are vacant, producing hexagonal tunnels in which M atoms are located. It is shown that in the two kinds of compounds the same linear chains and M' 3X17 groups of pentagonal bipyramids are present, and that the transformation of the U 3O 8 structure into the fluorides can be achieved by an ordered substitution of some linear … U?O?U?O … chains by … M- M- M … chains. All these structures can be described with the same structural model based on the chemical twinning principle.

Aléonard, S.; Le Fur, Y.; Champarnaud-Mesjard, J. C.; Frit, B.; Roux, M. Th.

1983-01-01

382

La Linguistica Aplicada a la Relacion Paradigmatica entre los Verbos "Ser" y "Estar" (Linguistics Applied to the Paradigmatic Relationship between the Verbs "Ser" and "Estar")  

ERIC Educational Resources Information Center

Speakers of Italian often have problems mastering Spanish because they erroneously believe its great similiarity to Italian makes it easy to learn. One of the fundamental problems is the lack of ability to choose the correct verb, "ser" or "estar," both equivalents of the Italian "essere." (Text is in Spanish.) (CFM)

Marchetti, Magda Ruggeri

1977-01-01

383

COMPARACIÓN ENTRE INTROVERTIDOS Y EXTROVERTIDOS EN EL NIVEL DE ANSIEDAD AL ESCUCHAR MÚSICA RELAJANTE A comparison of anxiety levels between introvert and extrovert subjects while listening relaxing music  

Microsoft Academic Search

This paper compares the level of anxiety between extrovert and introvert in- dividuals while listening relaxing music. A sample of 184 subjects (92 extra- vert and 92 introvert) was used in order to measure their level of anxiety by using the Inventory of State-Trait Anxiety. Results show that the introvert subjects reduced significantly their anxiety than extrovert ones while listening

Roberto Valderrama Hernández; Alejandro Campos Azuara; Julieta Vera Ramírez; Gladys Patricia; Castelán Rojas

2009-01-01

384

Entre dicho y hecho …: An Assessment of the Application of Research from Second Language Acquisition and Related Fields to the Creation of Spanish CALL Materials for Lexical Acquisition  

Microsoft Academic Search

Despite the problems presented by lexical errors in second language (L2) com- munication, most computer assisted language learning (CALL) programs tend to focus on the acquisition of grammar points rather than on the development of the L2 lexicon. In addition, CALL vocabulary tasks are typically limited in scope and mechanical in nature, covering mostly basic lexical meanings and ignor- ing

Barbara A. Lafford; Peter A. Lafford; Julie Sykes

385

Psychological Correlates of the Transmission and Acceptance of Rumors about AIDS = Correlates Psychologiques Entre la Transmission et l'Acceptation des Rumeurs sur le SIDA.  

ERIC Educational Resources Information Center

Public reactions to the Acquired Immune Deficiency Syndrome (AIDS) crisis are accompanied by the sorts of emotional and cognitive factors that have been identified by researchers as predictors of rumor generation and transmission. The present investigation attempted to ascertain the extent that various subjective factors (including anxiety,…

Kimmel, Allan J.

386

RGENDF: programa interface entre o codigo NJOY e codigos que utilizam secoes de choque multigrupo. (RGENDF: interface program between NJOY code and codes which use multigroup cross sections).  

National Technical Information Service (NTIS)

An interface program, for reformatting multigroup cross section libraries generated by NJOY into ENDF/B-V format and Expanda, PFCOND and Compar input formats, is presented. (author). (Atomindex citation 22:069921)

E. S. Chalhoub J. Anaf

1987-01-01

387

Estudio comparativo entre dos fuentes alimentarias aportadoras de ácidos grasos poliinsaturados n-3 y su efecto sobre el timo y el perfil lipídico de ratas  

Microsoft Academic Search

SUMMARY. Comparative study between two different sources of n-3 poliunsaturated fatty acids and it effect on thymus and lipid profile in rats. In the present paper we analyzed the effect caused by different recovery diets enriched with n-3 polyunsaturated fatty acids (PUFA n-3) on thymus and serum lipid pattern. Severe depleted weanling Wistar rats (D) were divided in three groups

Inés Fernandez; Anabel N. Pallaro; Nora H. Slobodianik

2007-01-01

388

DYNAMICS OF SOMATIC CELL-LINEAGE COMPETITION IN CHIMERAS OF Hydractinia symbiolongicarpus (CNIDARIA: HYDROZOA) Dinámica de competencia entre líneas celulares somáticas en quimeras de Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa)  

Microsoft Academic Search

Sessile colonial invertebrates often fuse with conspecifics to form chimeras. Chimerism represents an unequivocal instance of within-individual selection where genetically different cell-lineages compete for representation in the somatic and gametic pools. We analyzed temporal and spatial variations in somatic cell-lineage composition of laboratory-established chimeras of the hydroid Hydractinia symbiolongicarpus (Cnidaria: Hydrozoa). Using three clones with different allotypic specificities (i.e., two

RYAN S. SCHWARZ; LUIS F. CADAVID

389

COMPETIÇÃO ENTRE ESPÉCIES FLORESTAIS NATIVAS EM IRATI - PR, CINCO ANOS APÓS O PLANTIO (Competition of native forest tree species in Irati — PR, five years after planting)  

Microsoft Academic Search

The objective of this study was to collect information in the behaviour and silvicultural characteristics for eight forest tree species nativa to the Irati region in the State of Paraná, Brazil, five years after planting, when planted in pure stands in clear- cut areas. The studyied species are \\

Paulo Ernani; Ramalho Carvalho

390

Agricultural influence on the hydrogeochemistry of the sub-basins of the Verde, Entre Ribeiros and Escuro Rivers of Paracatu Hydrographic Basin (MG) – Brazil  

Microsoft Academic Search

Purpose – Of the numerous hydrogeochemical river-water transformations provoked by intense and irrational soil practices, heavy metal contamination by agrochemical usage is the most worrisome. Long-term metal accumulation can be transported by rainwater, during storms, contaminating rivers. Data on this type of contamination are still scarce, principally in developing countries, such as Brazil. This paper aims to evaluate the influence

Maria Augusta Gonçalves Fujaco; Mariangela Garcia Praça Leite

2010-01-01

391

RELACIÓN ENTRE VIGOR INICIAL, RENDIMIENTO Y SUS COMPONENTES EN POBLACIONES DE MAÍZ CHALQUEÑO * RELATIONSHIP BETWEEN INITIAL VIGOR, YIELD AND ITS COMPONENTS IN CHALQUEÑO MAIZE POPULATIONS  

Microsoft Academic Search

Initial vigor and its relationship with grain yield and its components were evaluated in 28 maize (Zea mays L.) populations of the Chalqueño race. Fourteen were collected from the Purepecha Mountain Range, in the state of Michoacan, nine from the Chalco Valley, in the State of Mexico, and fi ve from other states. Vigor was measured through the accelerated aging

Felipe de Jesús; Leobigildo Córdova Téllez; Amalio Santacruz Varela; Fernando Castillo González; Elizabeth Cárdenas Soriano; Adriana Delgado Alvarado

2007-01-01

392

Entre dois mundos: vida quotidiana de criancas portuguesas na america [Between Two Worlds: The Daily Life of Portuguese Children in America].  

ERIC Educational Resources Information Center

This Portuguese reader with accompanying teacher's guide describes the culture shock that Portuguese children and their families face when they immigrate to North America. The reader is divided into 75 short stories about the families that come from the rural areas of Portugal where there has been little industrialization. The purpose of the…

de Meneses, Fernando

393

ASOCIACIÓN ENTRE PUDRICIÓN TEXANA (Phymatotrichopsis omnivora) E INSECTOS BARRENADORES DEL NOGAL (Carya illinoensis)* ASSOCIATION BETWEEN COTTON ROOT ROT (Phymatotrichopsis omnivore) AND BORER INSECT OF PECAN TREE (Carya illinoensis)  

Microsoft Academic Search

Euplatypus segnis (Chapuis) (Coleoptera: Platypodidae) causes severe damage to pecan (Carya illinoensis) trees at Coahuila, Mexico. The present study was carried out during 1999-2001 in a 90 ha pecan orchard, divided in eight lots, during 1999-2001. The trees were counted and clasified in four categories: attacked by borer insects and with symptoms of cotton root rot (Phymatotrichopsis omnivora); only attacked

José Alfredo Samaniego-Gaxiola; Manuel Ramírez-Delgado; Aurelio Pedroza-Sandoval; Urbano Nava-Camberos

394

Comparaison entre les différentes commandes d'un moteur asynchrone pour un véhicule électrique en vue de minimiser les pertes de l'onduleur  

NASA Astrophysics Data System (ADS)

The losses of an inverter supplying an induction motor are compared for different vector control and pulse width modulation strategies. The study is carried out in simulation. As a conclusion, an optimal control in terms of losses is determined. Les pertes par conduction et par commutation d'un onduleur alimentant un moteur asynchrone sont comparées pour différentes solutions de contrôle vectoriel et de modulation de largeur d'impulsions. L'étude est réalisée en simulation. En conclusion, une commande optimale au niveau des pertes est déterminée.

Papazian, J.-C.; Rognon, J.-P.; Roye, D.; Delbosc, Ph.

1998-04-01

395

L'oxychromate Tl{_3(CrO_4)Sr_8Cu_4O_{16}} : phénomènes d'ordre entre le thallium et le chrome  

Microsoft Academic Search

Long range ordering between chromium and thallium has been evidenced for the first time in copper oxychromate Tl_3(CrO_4)Sr_8Cu_4O_{16} using HREM, XRD and ND. This compound, which crystallizes in an orthorhombic cell with a= 3.7803(1) Å Å Å Å Å Å, b=15.2573(2) Å Å Å Å Å Å and c=17.6737(3) Å Å Å Å Å Å derives from the \\

F. Letouzé; C. Martin; C. Michel; M. Hervieu; A. Maignan; R. Seshadri; B. Raveau

1998-01-01

396

Étude optoélectronique du mouvement de pédalage chez des cyclistes lors d'un exercice à 250 Watts. Comparaison entre une selle standard et une selle ergonomique  

Microsoft Academic Search

Purpose – The aim of this experiment was to evaluate and to compare the motor behaviour of cyclists who rode a bicycle equipped with a standard saddle and an ergonomic saddle that has no perineum support.Methods – Six trained cyclists (Mean ± SD: age, 37 ± 9 yr.; body mass, 74 ± 1 kg; height, 178 ± 5 cm) rode a bicycle equipped with a

O Edeline; E Dréano; I Bertoldi; J Weber

2001-01-01

397

Estudio comparativo de los hábitos de higiene oral entre alumnos de 1º, 3º y 5º de odontología de la Universidad Internacional de Cataluña  

Microsoft Academic Search

Summary Objectives: The aim of this paper is to analyze the oral hygienic habits in a student population of the International University of Catalunya (UIC) and to evaluate their periodontal health care. Material and Methods: In a total population of 217 students of 1st (34.1%), 3rd (39.6%9 and 5th (26.35%) a dental ques- tionnaire on oral hygiene and smoking habits

O. Freixa; O. Luis; D. Violant; A. Santos

398

¿SUPERPOSICION DE SÍNTOMAS O ERROR DIAGNOSTICO? Relación entre Síndrome de Intestino Irritable (SII) y enfermedad celíaca (EC) a propósito de un caso  

Microsoft Academic Search

This is a review on a relationship between Irritable Bowel Syndrome (IBS) and Celiac Disease (CD), that is bases in a patient with chronicle diarrhea. She was diagnosed as with IBS during many years. The association in this case with weigth loss, anemia and ulcerative stomatitis makes us think about other entities like CD . She is a 46 years

Diego Alonso; Eduardo Marini; Blas Gonzalez

399

L'accident du Toulourenc : une limite tectonique entre la plate-forme provençale et le Bassin vocontien à l'Aptien–Albien (SE France)  

Microsoft Academic Search

The WNW–ESE trending Toulourenc Fault Zone (TFZ) is the western segment of the major Ventoux–Lure Fault Zone, which separates the Provençal platform from the Baronnies Vocontian Basin. The TFZ was subject to polyphased Mid-Cretaceous movements, during the Early Aptian and Middle–Late Albian times. The latter faulting episode generated conglomerates and olistoliths resulting from dismantled faultscarps cutting Barremian–Bedoulian limestones. The deformation

Christian Montenat; Marie-Christine Janin; Pascal Barrier

2004-01-01

400

Cancer du col utérin stades IB et II opérable : comparaison rétrospective entre curiethérapie utérovaginale préopératoire et chirurgie première suivies d’une radiothérapie  

Microsoft Academic Search

Purpose. – To identify prognostic factors and treatment toxicity in a series of operable stages IB and II cervical carcinomas.Patients and methods. – Between May 1972 and January 1994, 414 patients (pts) with cervical carcinoma staged according to the 1995 FIGO staging system underwent radical hysterectomy with (n=380) or without (n=34) bilateral pelvic lymph node dissection. Lateral ovarian transposition to

D. Atlan; E. Touboul; E. Deniaud-Alexandre; J. P. Lefranc; V. Ganansia; A. Bernard; J. M. Antoine; D. Jannet; P. E. Lhuillier; M. Uzan; C. Genestie; M. Antoine; M. Jamali; J. Milliez; S. Uzan; J. Blondon

2002-01-01

401

Comparaison entre les Procedes Sol-Gel de la Zircone et de l'Alumine (Comparison of Sol-Gel Procedures for Zircon and Alumina).  

National Technical Information Service (NTIS)

Zirconium and aluminum oxide sol-gel procedures are reviewed. Published results are presented, including both the physical and chemical aspects of the procedures. The differences in zircon and alumina behavior are explained. It is concluded that for both,...

A. C. Pierre

1988-01-01

402

Étude de la Solution Solide Entre Tungstate et Tellurate de Magnésium: Pb 2MgW xTe (1- x) O 6  

NASA Astrophysics Data System (ADS)

The solid solutions Pb 2MgW xTe (1- x) O 6was prepared and investigated by dielectric measurements, DSC, X-ray, and neutron powder diffraction. A phase diagram is proposed. Above 312 K the structure is cubic (space group Fmoverline3m) for all xvalues (0? x?1). Around 190 K and for x?0.4, the incommensurate phase transition of Pb 2MgTeO 6is observed. It is little affected in this range by the W rate.The compositions x?0.8 undergo the orthorhombic/commensurate phase transition of Pb 2MgWO 6. This transition is very sensitive to the amount of Te present. The transition temperature and the orthorhombic distortion decrease quickly with increasing Te content. For 0.6< x<0.8 the transition is partial. In the range 0.4< x<0.6 the situation is more complex, both commensurate and incommensurate phases being observed at low temperature. The structure corresponding to x=0.4 has been determined by neutron powder diffraction at 12 K. It is isostructural to the incommensurate phase of Pb 2MgTeO 6. The orthorhombic/commensurate structures (space group Pmcn) of x=0.5, 0.7, and 0.9 were determined by X-ray powder diffraction at 80 K. The atomic displacements from the cubic positions decrease with increasing Te content.

Rivezzi, N.; Sciau, Ph

1998-09-01

403

Termoluminescencia do LiF: Mg, Ti entre 77 e 315 K. (Thermoluminescence of LiF: Mg, Ti between 77 and 315 K).  

National Technical Information Service (NTIS)

A special thermoluminescent system was developed. It is able to operate right from liquid nitrogen temperature and also permits the determination of the sample thermoluminescent emission spectrum. Using this system, the thermoluminescence displayed by 77 ...

L. A. R. Rosa

1989-01-01

404

Estado nutricional de crianças índias do Alto Xingu em 1980 e 1992 e evolução pondero-estatural entre o primeiro e o quarto anos de vida  

Microsoft Academic Search

This study focused on the under-five population of the Alto Xingu region in Brazil, with the following objectives: (1) to evaluate height and weight increment from the first through the fourth years of life and (2) to compare nutritional status in 1980 and 1992. Height and weight increases were evaluated in 81 children. Weight and height were measured in 264

Mauro Batista de Morais; Ulysses Fagundes Neto; Ângela Peixoto de Mattos; Roberto Geraldo Baruzzi

2003-01-01

405

Fidélité à la marque, fidélité à l'enseigne: une analyse des déterminants des rapports de force entre producteurs et distributeurs  

Microsoft Academic Search

[eng] Within-brand and within-store competition: a determinant analysis of the balance of power between manufacturers and retailers - The growing importance of mass distribution has transformed the balance of power between manufacturers and retailers. Regarding the limited effectiveness of numerous laws (Royer, Raffarin, Galland), which were supposed to restrain the increasing power of retailers, an accurate analysis of the relationships

Stéphane Caprice

2004-01-01

406

La prédisposition a la recherche d'expériences comme caractéristique individuelle : un élément de la complémentarité entre théorie classique et approche expérientielle  

Microsoft Academic Search

Approches traditionnelle et expérientielle du comportement du consommateur sont présentées comme complémentaires. Cette recherche étudie une des manifestations de cette complémentarité en introduisant la prédisposition des individus à la recherche d'expériences dans le processus de décision traditionnel. Les résultats de l'analyse quantitative démontrent que la prédisposition à la recherche d'expériences renforce la place de l'attitude aux côtés de l'intention d'achat

Etienne Bressoud

2007-01-01

407

Previniendo el Uso de Drogas entre Ninos y Adolescentes: Una Guia Basada en Investigaciones (Preventing Drug Use among Children and Adolescents: A Research-Based Guide).  

ERIC Educational Resources Information Center

This question and answer guide provides an overview of the research on the origins and pathways of drug abuse, the basic principles derived from effective drug abuse prevention research, and the application of research results to the prevention of drug use among young people. The basic principles derived from drug abuse prevention research are…

Sloboda, Zili; David, Susan L.

408

Sequence similarity between the cp gene and the transgene in transgenic papayas = Similaridade de seqüência entre o gene cp do vírus e do transgene presente em mamoeiros transgênicos  

Microsoft Academic Search

The Papaya ringspot virus (PRSV) coat protein transgene present in 'Rainbow' and 'SunUp' papayas disclose high sequence similarity (>89%) to the cp gene from PRSV BR and TH. Despite this, both isolates are able to break down the resistance in 'Rainbow', while only the latter is able to do so in 'SunUp'. The objective of this work was to evaluate

M. T. Souza; M. Teixeira; D. Gonsalves

2005-01-01

409

La mosca blanca Bemisia tabaci (Gennadius) como plaga y vectora de virus en fríjol común (Phaseolus vulgaris L.) The whitefly Bemisia tabaci (Gennadius) as pest and vector of plant viruses of common bean (Phaseolus vulgaris L.)  

Microsoft Academic Search

2 Resumen. La mosca blanca Bemisia tabaci es una de las plagas más ampliamente distribuidas en regiones tropicales y subtropicales del mundo donde afecta más de 600 especies de plantas cultiva- das y silvestres. Los daños que causa se deben a diversos efectos del insecto en las plantas atacadas, como el debilitamiento de la planta por la extracción de nutrientes;

MARÍA ELENA CUÉLLAR; FRANCISCO J. MORALES

2006-01-01

410

Estudo comparativo entre a artroplastia discal tipo metal-metal e a artrodese lombar na discopatia lombar degenerativa Comparative study of lumbar disc arthroplasty and lumbar arthrodesis in lumbar degenerative disc disease Estudio comparativo entre la artroplastia discal tipo metal-metal y la artrodesis lumbar en la discopatía lumbar degenerativa  

Microsoft Academic Search

Objective: to realize a retrospective, long-term study, with clinical com- parative analysis between the pre and post-operative conditions of the patients submitted to lumbar disc replacement using metal-metal type disc, and the group operated for the traditional arthrodesis technique, in a single level for degenerative disc disease. Methods: eighteen patients had been submitted to the disc replacement with metal-metal type

Fernando Dario; Lyra de Freitas Coutinho; Luiz Cláudio Schettino

2008-01-01

411

Financial Integration and Interest Rate Linkages in Industrial Countries, 1958-71 (Intégration financière et relations entre les taux d'intérêt des pays industriels, 1958-71) (Integración financiera y relaciones entre los tipos de interés en los países industriales, 1958-71)  

Microsoft Academic Search

This article focuses on theoretical and policy issues posed by financial integration among industrial countries since the mid-1950s. The problems of measuring international financial integration and of estimating its trend over the years are also explored. The role of the Euro-dollar market, as a major financial intermediary that channels short-term funds between the money markets of the industrial countries, is

Victor Argy; Zoran Hodjera

1973-01-01

412

Hydraulic properties and scale effects investigation in regional rock aquifers, south-western Quebec, Canada  

NASA Astrophysics Data System (ADS)

This paper reports on the characterization of hydraulic properties of regional rock aquifers carried out within a groundwater resources assessment project in the St. Lawrence Lowlands of south-western Quebec. To understand the aquifer behavior at both the fracture level and at field scale, hydraulic investigations were carried out using various aquifer tests. The groundwater flow at the local scale is controlled mostly by the fracture system. Results of the constant-head injection tests show a weak decreasing trend of hydraulic conductivity with depth indicating that a major part of the groundwater flow occurs in the first meters of the rock sequence. At the regional scale, the equivalent porous media approach is applicable. The hydraulic conductivity measurements were correlated to the scale of the aquifer tests expressed with the investigated aquifer volume. A simple interpolation procedure for the hydraulic conductivity field was developed based on the distance between field measurements and the tested aquifer volumes. The regional distribution of the hydraulic conductivity for the major fractured aquifer units indicates that dolostone is the most permeable whereas sandstone and crystalline rocks are the least permeable units. Este artículo trata de la caracterización de las propiedades hidráulicas en acuíferos regionales rocosos, la cual se llevó a cabo dentro del proyecto de evaluación de los recursos de agua subterránea en St. Lawrence Lowlands al suroeste de Quebec. Para entender el comportamiento del acuífero tanto a nivel de fractura como a escala del campo, se ejecutaron investigaciones hidráulicas usando varias pruebas de acuífero. El flujo del agua subterránea a escala local está controlado principalmente por el sistema de fracturas. Los resultados de las pruebas de inyección con cabeza constante muestran una tendencia decreciente débil de la conductividad hidráulica con la profundidad, indicando que la mayor parte del flujo de agua subterránea sucede en los primeros metros de la secuencia rocosa. A escala regional se puede aplicar la aproximación equivalente de medios porosos. Las medidas de la conductividad hidrálica fueron comparadas con la escala de las pruebas del acuífero, expresadas con el volumen investigado del acuífero. Se desarrolló un proceso de interpolación simple para la conductividad hidráulica de campo, con base en la distancia entre las medidas de campo y los volúmenes probados del acuífero. La distribución regional de la conductividad hidráulica, para las unidades acuíferas fracturadas mayores, indica que la dolomita es más permeable mientras que la arenisca y las rocas cristalinas son las unidades menos permeables. L'article présente les propriétés hydrauliques d'un aquifère régional rocheux qui ont été mesurées dans le cadre d'un projet concernant l'estimation de la ressource en eau de la plaine de St. Lawrence située dans la partie sud-ouest de Quebec. Affin de comprendre le comportement de l'aquifère tant à l'échelle de fracture qu'à l'échelle régionale on a mené des investigations hydrauliques en utilisant des essais differents. À l'échelle locale l'écoulement est déterminé en principal par le système des fractures. Les résultats des essais d'injection au niveau constant ont montré une tendence de décroissance de la conductivité hydraulique avec la profondeur ce qui indique que l'écoulement ait lieu en principal dans les premiers mètres de la structure rocheuse. À l'échelle règionale on peut appliquer l'approche de milieux poreux equivalent. Les mesures de conductivité hydraulique ont été corrélées avec l'échelle des essais de pompage exprimée en termes de volume investigué de l'aquifère. On a mis au point une méthode simple d'interpolation pour le champ de la conductivité hydraulique basée sur la distance entre les essais in situ et les volume investigués de l'aquifère. La distribution règionale de la conductivité hydraulique montre que pour la majorité des unités de roche fracturé les plus perméable sont

Nastev, M.; Savard, M. M.; Lapcevic, P.; Lefebvre, R.; Martel, R.

413

Tools for evaluating Lipolexis oregmae (Hymenoptera: Aphidiidae) in the field: Effects of host aphid and host plant on mummy location and color plus improved methods for obtaining adults  

SciTech Connect

Lipolexis oregmae Gahan was introduced into Florida in a classical biological control program directed against the brown citrus aphid, Toxoptera citricida (Kirkaldy), on citrus. Prior to evaluating distribution, host range, and potential nontarget effects of L. oregmae in Florida, we evaluated the role of other potential host aphids and host plants on mummy production and location. Under laboratory conditions, this parasitoid produced the most progeny on the target pest, the brown citrus aphid on citrus. This parasitoid, unlike the majority of aphidiids, did not produce mummies on any of the host plants tested when reared in black citrus aphid T. aurantii (Boyer de Fonscolombe) on grapefruit, spirea aphid Aphis spiraecola Patch on grapefruit and pittosporum, cowpea aphid A. craccivora Koch on grapefruit and cowpeas, or melon aphid A. gossypii Glover on grapefruit and cucumber. Thus, sampling for L. oregmae mummies of these host aphids and host plants must involve holding foliage in the laboratory until mummies are produced. This parasitoid requires high relative humidity to produce adults because no adults emerged when mummies were held in gelatin capsules, but high rates of emergence were observed when mummies were held on 1.5% agar plates. In addition, we compared the color of 6 aphid hosts and the color of mummies produced by L. oregmae when reared in them to determine if color of mummies could be used to identify L. oregmae . Mummy color varied between aphid hosts and tested host plants, and is not a useful tool for identifying L. oregmae for nontarget effects. (author) [Spanish] Lipolexis oregmae Gahan fue introducida en Florida por medio de un programa de control biologico clasico dirigido contra el afido pardo de los citricos, Toxoptera citricida (Kirkaldy), sobre Citrus. Prioritario a la evaluacion de la distribucion, el rango de los hospederos y los efectos potenciales de L. oregmae sobre los organismos que no son el enfoque de control en la Florida, nosotros evaluamos el papel de otras especies de afidos y plantas hospederas potenciales sobre la produccion y ubicacion de las momias. Bajo condiciones de laboratorio, este parasitoide produjo el mayor numero de progenies sobre la especie de plaga enfocada, el afido pardo de los citricos sobre Citrus . Este parasitoide, no como la mayoria de los afidiidos (Hymenoptera), no produjo momias sobre cualquiera de las plantas hospederas probadas cuando fue criado sobre el afido negro de los citricos, ( T. aurantii (Boyer de Fonscolombe)) en toronja, el afido spirea (Aphis spiraecola Patch) en toronja y pittosporum, el afido del caupi (A. craccivora Koch) en toronja y caupi o el afido del melon (A. gossypii Glover) en toronja y pepino. Asi, el muestreo para momias de L. oregmae de estas especies de afidos hospederos y plantas hospederas tiene que incluir el mantenimiento de follaje en el laboratorio hasta que se produzcan las momias. Este parasitoide requiere una alta humedad relativa para producir los adultos por que ningun adulto emergio cuando las momias fueron mantenidas en capsulas de gelatina, pero una tasa alta de emergencia de adultos fue observada cuando se mantuvo las momias en platos con agar al 1.5%. Ademas de esto, nosotros comparamos el color de 6 especies de afidos hospederos, asi como el color de las momias producidos por L. oregmae cuando fue criado sobre ellos para determinar si se puede usar el color de las momias para la identificacion de L. oregmae . El color de las momias varia entre las especies de afidos hospederos y las plantas hospederas probadas, por lo que no es una herramienta util para la identificacion de L. oregmae o para la evaluacion de su efecto sobre los organismos que no son el enfoque del control. (author)

Singh, R.; Hoy, M.A. [Department of Entomology and Nematology, University of Florida, Gainesville, FL (United States)

2007-03-15

414

o sup 14C como tracador do fluxo do carbono assimilado pelas plantas (milho, cana-de-acucar, feijao) e sua liberacao ao solo. ((14)C as tracer in the carbon flow assimilated by the plants (maize, sugar cane, bean) and it liberation to the soil).  

National Technical Information Service (NTIS)

The flow of carbon in three different crops, maize, beans and sugar cane was studied by use of (sup 14)V. The plants were exposed to an atmosphere with a constant concentration of the tracer for 12 hours in a biosynthesis chamber. The detection of the iso...

B. J. F. Paula Eduardo

1987-01-01

415

EFECTIVIDAD DE EXTRACTOS BOTÁNICOS DE DIEZ PLANTAS SOBRE LA MORTALIDAD Y REPELENCIA DE LARVAS DE Rhynchophorus palmarum L., INSECTO PLAGA DEL PIJUAYO Bactris gasipaes KUNTH EN LA AMAZONÍA DEL PERÚ Effectiveness of botanical extracts from ten plants on mortality and larval repellency of Rhynchophorus palmarum L., an insect pest of the Peach palm Bactris gasipaes Kunth in Amazonian Peru  

Microsoft Academic Search

A B S T R A C T Pest resistance to chemical insecticides has grown in recent years, which is the motive for the search for alternative methods, such as plants with larvicidal activity. The objective of this research was to evaluate mortality and larval repellency of Rhynchophorus palmarum L. (Curculionidae), a pest of the Peach palm Bactris gasipaes Kunth

416

HÍBRIDOS Y PROGENITORES DE SORGO TOLERANTES AL FRÍO. III: CALIDAD DE LA SEMILLA COSECHADA DE PLANTAS INFECTADAS CON Fusarium verticillioides (Sacc.) Nirenberg COLD TOLERANT SORGHUM HYBRIDS AND PARENTAL LINES. III: QUALITY OF SEEDS HARVESTED FROM PLANTS INFECTED WITH Fusarium verticillioides (Sacc.) Nirenberg  

Microsoft Academic Search

One factor that limits commercial expansion of sorghum (Sorghum bicolor L. Moench) in the Central High Valleys of México is its susceptibility to stem and head blight, a disease caused by Fusarium verticillioides (F. moniliforme). Because of the lack of information on quality of seed harvested from plants infected with this fungus, in 2003 an experiment was set up in

Manuel Livera-Muñoz

2007-01-01

417

DURACIÓN DEL EFECTO REVIGORIZANTE DE PODAS SEVERAS DE PLANTAS ADULTAS DE AVELLANO EUROPEO (Corylus avellana L.) cv. Negretta SOBRE EL CULTIVO IN VITRO Duration of the reinvigorating effect of severe pruning of mature European hazelnut plants (Corylus avellana L.) cv. Negretta with in vitro cultivation  

Microsoft Academic Search

A B S T R A C T The duration of the reinvigorating effect of severe pruning on mature European hazelnuts (Corylus avellana L.) cv. Negretta was analyzed. The in vitro stimulation and proliferation rate of the resulting explants from cutting stimulation obtained from adult plants not pruned (T1), epicormic shoots of non-pruned plants (T2), once-pruned plants (T3) and plants

Manuel Sánchez-Olate; Darcy Ríos; Roberto Rodríguez; María Elena Materán; Guillermo Pereira

2004-01-01

418

SELETIVIDADE E CONTROLE POR MISTURAS DE HERBICIDAS EM ALGODOEIRO HERBÁCEO1  

Microsoft Academic Search

RESUMO: Utilizam-se misturas de herbicidas para evitar a resistência de plantas daninhas a herbicidas e obter melhor eficiência de controle das plantas daninhas. Conduziu-se, no Campo Experimental da Embrapa Algodão, Barbalha, CE, experimento objetivando avaliar o efeito de misturas duplas, triplas e quádruplas de herbicidas, envolvendo Diuron, pendimethalin, metolachlor e oxadiazon, aplicadas em pré-emergência, no controle de plantas daninhas em

ANTONIA ELIENE DUARTE; JOSÉ RODRIGUES PEREIRA; JOÃO BOSCO PITOMBEIRA; MARIA ARLENE PESSOA DA SILVA; FANUEL PEREIRA DA SILVA

419

Segment-specific retention of a larval neuromuscular system and its role in a new, rhythmic, pupal motor pattern in Manduca sexta  

Microsoft Academic Search

At pupation in Manduca sexta, accessory planta retractor muscles and their motoneurons degenerate in segment-specific patterns. Accessory planta retractor\\u000a muscles in abdominal segments 2 and 3 survive in reduced form through the pupal stage and degenerate after adult emergence.\\u000a Electromyographic and electrophysiological recordings show that these accessory planta retractor muscles participate in a\\u000a new, rhythmic `pupal motor pattern' in which

D. J. Sandstrom

1998-01-01

420

Non medical use and abuse of psychoactive substances among university students in health-related courses Experimentação, uso e abuso de substâncias psicoativas entre universitários da área da saúde  

Microsoft Academic Search

Objective: To understand the pattern of consumption of legal and illicit drugs among students of health-related courses and, if there are users among the participants in the survey, and find out whether they wish to participate in prevention and treatment programs. Methods: Quantitative and descriptive study performed using a self-applicable questionnaire. The study population consisted of students at a private

Clesio Nepomuceno; Ana Paula de Carvalho; Valéria Aparecida de Paula; Viviane Cristina de Souza; Dorisdaia Carvalho de Humerez

421

Distribuicao DOS Espacos Verdes Em Areas Urbanas: Cartografia E Analise Comparative Entre Dados TM/LANDSAT E HRV/SPOT (Distribution of Green Areas in Urban Areas: Cartography and Comparative Analysis of LANDSAT TM and HRV/SPOT Data).  

National Technical Information Service (NTIS)

The intense urbanization process that took place during the last decades in Brazil has strongly reduced the vegetation component, thus affecting the quality of life in these urban areas. Currently, the qualitative and quantitative mapping of vegetation wi...

A. L. R. Carrara C. Foresti J. R. Dossantos

1991-01-01

422

Variação da qualidade da madeira entre grupos fenotípicos de clones de Eucalyptus urophylla S.T. Blake da Ilha de Flores, Indonesia Wood quality variation among phenotypic groups of clones Eucalyptus urophylla S.T. Blake from Flores Island, Indonesia  

Microsoft Academic Search

RESUMO: O objetivo do presente trabalho foi estudar parâmetros de qualidade da madeira (densidade básica, comprimento, largura, diâmetro e espessura da parede das fibras) de clones de Eucalyptus urophylla, da Ilha de Flores, Indonésia, agrupados pelas características silviculturais e botânicas. A população base constituiu-se de um banco clonal, com 6 anos de idade, implantado no Horto Florestal Nossa Senhora Aparecida,

Osmar Francisco Ruy; Mário Ferreira; Mário Tomazello Filho

423

AS DOENÇAS SEXUALMENTE TRANSMISSÍVEIS SÃO PROBLEMAS ENTRE GESTANTES NO CEARÁ? ARE SEXUALLY TRANSMITTED DISEASES A PROBLEM TO PREGNANT WOMEN IN CEARÁ? MENÇÃO HONROSA - PRÊMIO MELHOR TRABALHO COMPLETO, CATEGORIA: EPIDEMIOLOGIA  

Microsoft Academic Search

Introduction: the complications of STD (Sexually Transmitted Diseases) include ectopic pregnancy, spontaneous abortions, stillbirth, prematurity, conge- nital perinatal and puerperal infection. In Brazil, studies in pregnant women are scarce, although STD have an important impact in pregnancy outcome. Objective: to estimate the prevalence of syphilis, gonorrhea, chlamydeous, and trichomoniasis in pregnant women in two municipalities of Ceará and to identify

Telma A Martins; Pierre Y-Bello; Martha D Bello; Lígia Regina; SK Pontes; Lúcia V Costa; Iracema S Miralles; Telma Régia

424

Sinergismo entre radiacao ultravioleta e redutona em Escherichia coli UVR: analise quantitativa das lesoes produzidas. (Synergism between ultraviolet radiation and reductone in Escherichia coli UVR: quantitative analysis of produced injuries).  

National Technical Information Service (NTIS)

The relationship between cell viability and DNA-single and double-strand breaks induced by UV-reductone treatment of E.coli AB1157 and AB1886 cells was studied. A molecular and quantitative analysis was done by sedimentation in sucrose gradients. Bacterio...

H. C. Mota

1980-01-01

425

Variabilité intra-saisonnière et multi-décennale de la téléconnexion entre les pressions de surface (100°W–50°E ; 30°–70°N) et les ENSO\\/LNSO (1873–1996)  

Microsoft Academic Search

The relationships between an index of the NINO3.4 region and the wintertime sea level pressure (hereafter SLP) anomalies on the extratropical North Atlantic and the bordering areas (100°W–50°E; 30°–70°N) are studied for 1873–1996. This study emphasizes the need of a careful pooling of months and the multi-decadal variability of the ENSO\\/LNSO influence on the extratropical North Atlantic. We calculate the

Isabelle Gouirand; Vincent Moron

2000-01-01

426

Similarities between punching and shear strength of steel fiber reinforced concrete (SFRC) slabs and beams Similaridades entre resistência à punção em lajes-cogumelo e ao cisalhamento em vigas de concreto armado com fibras de aço  

Microsoft Academic Search

Resumo This paper discusses the influence of steel fiber in both punching strength of flat slabs and shear strength of concrete beams. Similarities in the structural behavior were observed in an experimental analysis of analogous slabs and beams. The analogous slabs and beams had the same height, longitudinal reinforcement ratio and concrete properties. Concrete mixtures were designed to attain different

J. B. DE HANAI; K. M. A. HOLANDA

2008-01-01

427

Toward Gender Equality: The Role of Public Policy. An Overview (Vers l'Egalite des Sexes: Le Role des Politiques Nationales. Apercu General) (Hacia la Igualdad Entre Hombres y Mujeres: El Papel de las Politicas Publicas. Panorama General).  

National Technical Information Service (NTIS)

The Overview, based on a World Bank report, outlines what governments and development agencies can do to work toward greater gender equality--one of the best investments a society can make. Public policy can affect investments in health, education, and in...

1995-01-01

428

Antecedentes de la evolucion historica de los recursos de uranio de la region de Cuyo entre 1951-1968. (Antecedents of historical evolution of the uranium resources in the Cuyo region, between 1951 and 1968).  

National Technical Information Service (NTIS)

The present article pretends to summarize the initial stage of the development of national uranium resources - focusing the labor done by the Escuela Superior de Ingenieria en Combustible of the Universidad Nacional de Cuyo - between the years 1951 and 19...

A. A. Vergara Bai

1992-01-01

429

Actitud hacia la donación renal de vivo entre el personal sin relación con el trasplante en un hospital con programa de trasplante de órganos sólidos de cadáver y de vivo  

Microsoft Academic Search

IntroductionBecause of the shortage of kidney organs available for transplantation and the favorable outcomes described in living donation, this type of donation is necessity in Spain. However, living donation has yet to be developed and this may be partly because hospital personnel do not have an entirely favorable attitude toward this type of donation. The objective of this study was

Antonio Ríos-Zambudio; Pablo Ramírez; Laura Martínez; Mariano J. Montoya; M. Mar Rodríguez; Jesús Alcaraz; Dolores Lucas; Pascual Parrilla

2007-01-01

430

Preliminary Modelling Study of Geochemical Interactions between a Used-Fuel Disposal Vault and the Surrounding Geosphere (Etude de Modelisation Preliminaire des Interactions Geochimiques Entre une Enceinte de Stockage Permanent de Combustible Irradie et la Geosphere Environnante).  

National Technical Information Service (NTIS)

The purpose of the study was to estimate the general magnitude and significance of vault-induced geochemical changes over an expected range of temperatures. The results of the preliminary modeling are used broadly to evaluate the implications of these cha...

J. McMurry

1995-01-01

431

Portrait des différences entre les genres dans le contexte de l'apprentissage de l'électricité en fonction de la certitude exprimée lors de la production de réponses  

Microsoft Academic Search

This exploratory research aims to describe changes in the “feeling-of-knowing” (FOK) experienced by high school students who are being introduced to the fundamental concepts of electricity through learning by discovery. The analysis focuses first on the initial state of boys and girls in terms of their prior experience and the perception they have of their abilities in science and technology,

Patrice Potvin; Martin Riopel; Patrick Charland; Julien Mercier

2011-01-01

432

Relación entre algunos aspectos climatológicos y el desarrollo de la langosta centroamericana Schistocerca piceifrons piceifrons en el Pacífico Norte de Costa Rica durante la fase cálida del fenómeno El Niño-Oscilacion Sur (ENOS)  

Microsoft Academic Search

Enviromental temperature, relative humidity, precipitation and solar radiation are meteorological elements that affect distribution, growth rate, reproduction, migration and adaptation ways of insects. Some physilogics activities of locust are influenced by climatic patterns and season conditions. The Phases Change wich is a biological and morfological transformation of various species of gregarius locusts, is influenced by meteorological elements. On this way,

JOSÉ A. RETANA

433

Sobrepeso e obesidade e sua relação com a prática de atividade física e o consumo dietético entre adolescentes Overweight and obesity and their relation to physical activity and diet among adolescents  

Microsoft Academic Search

Introduction: Obesity in teenagers has been studied in many countries. It has been associated to eating habits and physical inactivity. Objective: This study aimed to analyze the frequency of overweight and obesity as related to physical activity and eating habits among adolescents. Methods: A sample of randomly selected 285 subjects of both sexes with ages ranging from 10 to 19

Luciano Meireles de Pontes

434

Conversado con su Medico: Consejos para Lograr una Buena Comunicacion Entre las Personas de la Tercera Edad y su Doctor (Talking With Your Doctor: A Guide for Older People).  

National Technical Information Service (NTIS)

How well you and your doctor talk to each other is one of the most important parts of getting good health care. A good patient-doctor relationship is a partnership. You and your doctor can work as a team, along with nurses, physician assistants, pharmacis...

2004-01-01

435

Comparação entre três equações de referência para a espirometria em crianças e adolescentes com diferentes índices de massa corpórea* Comparison of three sets of reference equations for spirometry in children and adolescents with distinct body mass indices  

Microsoft Academic Search

Objective: To compare FEV 1 and FVC, calculated using three sets of reference equations (devised by Polgar & Promadhat, Hsu et al. and Mallozi in 1971, 1979 and 1995, respectively) and to determine whether the three are similar in predicting lung function in children and adolescents with distinct body mass indices (BMIs). Methods: The individuals were separated into four groups

Sarah Costa Drumond; Maria Jussara Fernandes Fontes; Marco Antônio Duarte; Joel Alves Lamounier; Maria da Glória; Rodrigues Machado

2009-01-01

436

Mesure de la force des muscles rotateurs de l'épaule chez des sportifs sains de haut niveau (natation, volley-ball, tennis) par dynamomètre isocinétique : comparaison entre épaule dominante et non dominante  

Microsoft Academic Search

Objective. – To compare lateral rotator (LR) and medial rotator (MR) muscle strength of both shoulders in a sport involving asymmetrical movements (tennis), symmetrical movements (swimming), and symmetrical and asymmetrical movements (volley-ball).Materials and methods. – Retrospective study of 42 healthy elite athletes (18 women: 14 tennis players, 19 swimmers and 9 volleyball players. We evaluated the strength of LR and

G. Gozlan; L. Bensoussan; J.-M. Coudreuse; J. Fondarai; V. Gremeaux; J.-M. Viton; A. Delarque

2006-01-01

437

Body mass index, body weight perception and common mental disorders among university employees in Rio de Janeiro Índice de massa corporal, percepção do peso corpo- ral e transtornos mentais comuns entre funcionários de uma universidade no Rio de Janeiro  

Microsoft Academic Search

Abstract Abstract Abstract Abstract Objective: Objective: Objective: Objective: Objective: We tested the hypothesis that inadequate self-perception of body weight with or without obesity would be associated with common mental disorders (CMD). Method: Method: Method: Method: Method: We analyzed cross-sectional data from 4,030 university employees participating in the longitudinal Pró-Saúde Study Phase 1 (1999) in Rio de Janeiro. Participants (22-59 years

Alessandra Bento Veggi; Claudia S Lopes; Eduardo Faersteina; Rosely Sichieria

438

Índice de massa corporal, percepção do peso corporal e transtornos mentais comuns entre funcionários de uma universidade no Rio de Janeiro Body mass index, body weight perception and common mental disorders among university employees in Rio de Janeiro  

Microsoft Academic Search

Abstract Abstract Abstract Abstract Objective: Objective: Objective: Objective: Objective: We tested the hypothesis that inadequate self-perception of body weight with or without obesity would be associated with common mental disorders (CMD). Method: Method: Method: Method: Method: We analyzed cross-sectional data from 4,030 university employees participating in the longitudinal Pró-Saúde Study Phase 1 (1999) in Rio de Janeiro. Participants (22-59 years

Alessandra Bento Veggi; Claudia S Lopes; Eduardo Faerstein; Rosely Sichieri

439

Análise faciológica e estratigráfica da planície costeira de Soure (margem leste da ilha de Marajó-PA), no trecho compreendido entre o canal do Cajuúna e o estuário Paracauari  

Microsoft Academic Search

Soures's coastal plain, eastern Marajó island (Pará), is formed by muddy and sandy deposits, low gradient areas submitted to tidal and wave processes. The morphological features are tidal flats, estuaries, tidal channels and barrier-beach ridges . The faciological and stratigraphical analysis of six vibra-core with medium deph of four meters and from outcrops allowed a caracterization of depositional environments, temporal

Carmena Ferreira de França; Pedro Walfir Martins e Souza Filho; Maâmar El-Robrini

2007-01-01

440

ASYMMETRIC INFORMATION IN RURAL FINANCIAL MARKETS AND INTERLINKING OF TRANSACTIONS THROUGH THE SELF-HELP GROUPS \\/ INFORMATIONS ASYMETRIQUES SUR LES MARCHES FINANCIERS RURAUX ET LA PRESENCE DE TRANSACTIONS DES GROUPEMENTS D'ENTRE-AIDE  

Microsoft Academic Search

In many developing countries small borrowers have traditionally relied on informal lenders for their credit needs because of the limitations of self-finance and the lack of access to bank credit. This paper discusses the small borrower's lack of access to bank credit and other financial services within the framework of the asymmetry of information that exists in rural financial markets.

Gilberto M. Llanto

1990-01-01

441

Comparison of Ionospheric Electron Density Profiles Obtained with the International Reference Ionosphere (IRI) 79 Model and Observed at Cachoeira Paulista Comparacao Entre Perfis de Densidade Eletro Nica DA Ionsfera, Obtidos Pelo Modelo IRI 79 E Observados Em Cachoeira Paulista.  

National Technical Information Service (NTIS)

An ionospheric computer model IRI 79 (International Reference Ionosphere) was implemented. With a computer program developed for the determination of of the the ionospheric profile N(h), using ionograms a comparative study between the observed and predict...

E. R. Depaula A. C. R. Desouza I. J. Kantor S. L. G. Dutra

1982-01-01

442

O Imperio como Argumento: Um Contraponto entre Joaquim Nabuco e o Bispo D. Jose Mauricio da Rocha (The Empire as Argument: A Counterpoint between Joaquim Nabuco and the Bishop Dom Jose Mauricio da Rocha).  

ERIC Educational Resources Information Center

Dialogs with the previous article establishing a comparative analysis between the political acceptance present in the reactionary speech of Dom Jose Mauricio da Rocha and in the monarchist words of Joaquim Nabuco. (PA)

Marson, Izabel Andrade

1998-01-01

443

Vinculacion Entre La Educacion Y El Mundo Del Trabajo: Informe Final. (Coloquio Regional Caracas, Venezuela, Septiembre 2-6, 1985) = The Linkage Between Education and Employment: Final Report of the Regional Colloquium (Caracas, Venezuela, September 2-6, 1985).  

ERIC Educational Resources Information Center

At this regional colloquium 13 papers were presented concerning the relationship between education and employment. Themes addressed were: (1) the transformation of the workplace by technology and science; (2) the future of the disadvantaged population as a consequence of the technological revolution; and (3) the resulting changes in the education…

United Nations Educational, Scientific, and Cultural Organization, Santiago (Chile). Regional Office for Education in Latin America and the Caribbean.

444

Nonbreeding-Season Drivers of Population Dynamics in Seasonal Migrants: Conservation Parallels Across Taxa Facteurs hors reproduction intervenant sur la dynamique des populations de migrateurs saisonniers : analogie entre divers taxons  

Microsoft Academic Search

For seasonal migrants, logistical constraints have often limited conservation efforts to improving survival and reproduction during the breeding season only. Yet, mounting empirical evidence suggests that events occurring throughout the migratory life cycle can critically alter the demography of many migrant species. Herein, we build upon recent syntheses of avian migration research to review the role of non-breeding seasons in

Anna M. Calvert; Sandra J. Walde; Philip D. Taylor

2009-01-01

445

Estudo da evolução dinâmica fluvial dos rios do Amazonas com base em imagens de RADAR e satélite nos últimos 30 anos, balanço entre área de erosão e deposição e possíveis conseqüências para a ocupação humana  

Microsoft Academic Search

The Amazon region as resultant of geologic history and the climate, shelters a more extensive fluvial system and of bigger liquid mass of the Land. The analysis of products of remote sensing in the Amazônia is the technique that still persists as the main tool to assist in the execution of diverse scientific works. The agreement of the fluvial dynamics

Amaro Luiz Ferreira

446

Le recours aux MEGC pour l’analyse de l’accord de partenariat économique entre l’union européenne et les pays ACP : une revue de la littérature  

Microsoft Academic Search

The implementation of the Economic Partnership Agreement (EPA) between the European-Union and the ACP (Africa-Caribbean-Pacific) countries requires the progressive tariff dismantling against the products originating from the European Union. Many African countries are worried about this agreement and ask for a closer examination on socio-economic, sectoral and regional impacts. The debate is all the more difficult because the GDP growth

Jean-Marc Philip

2006-01-01

447

Comparacao entre os codigos RELAP5/MOD1 e TRAC-PD2 na simulacao da experiencia CANON. (Comparison between RELAP5/MOD1 and TRAC-PD2 codes in the CANON experience).  

National Technical Information Service (NTIS)

The present work reports comparisons between experimental and theoretical data done with the RELAP5/MOD1 and TRAC-PD2 codes, with particular emphasis on RELAP5/MOD1 code run with basic experimental data from the CANON depressurization simulation. This exp...

G. Sabundjian R. L. Freitas T. Neves Conti

1991-01-01

448

RELAÇÃO ENTRE NÍVEL DE ATIVIDADE FÍSICA E DESEMPENHO NO TESTE DE AVALIAÇÃO FÍSICA DE MILITARES The relationship between physical activity level and performance of militaries in physical evaluation tests  

Microsoft Academic Search

This study aimed to examine the relationship between the level of physical activity (PA) and the performance test of Brazilian Army militaries in physical evaluation test (PET). The sample, made by 121 military volunteers members of a military unit in the garrison of Porto Alegre, is characterized by individuals with average age of 20.62 years (±3.83), average stature of 1.74

Carlos Ricardo; Gomes de Souza Rocha; Miguel Comerlato

449

Relación entre los niveles de carga viral y los niveles de linfocitos CD4 en el diagnóstico de Cryptosporidium spp. en heces de niños de la Clínica Pediátrica de VIH\\/SIDA del Hospital Universitario del Valle, Cali, Colombia  

Microsoft Academic Search

SUMMARY Introduction: Cryptosporidium spp. (C. spp.) cause morbi-mortality in children with AIDS. Objective: To identify the association between viral load, CD4 levels and C. spp., presence in feces of children with AIDS. Materials and methods: Observacional study in children of the Hospital Universitario del Valle of Cali. Data like age, gender, origin, consanguinity, treatment, stage, maternal survival and weight, were

MIREY S IUFFI; MARIO A NGULO; PÍO L ÓPEZ; VÍCTOR H UGO; CONSUELO R OJAS

2006-01-01

450

Relación entre el nivel de actividad física en escolares durante el fin de semana y la prevalencia de obesidad Relationship between the level of physical activity in school during the weekend and the prevalence of obesity  

Microsoft Academic Search

The objective of the work was to quantify the prevalence of being overweight and obese in a group of students of Ourense (Spain) and its relation with the physical activity levels during weekend. One hundred and eleven scholars with an average age of 11.3 years participated in this study. Among them 42.3% were female and 57.7% male. Weight, height and

Francisco García De la Montaña; Montserrat Míguez Bernárdez; Julia De la Montaña Miguélez

2011-01-01

451

Comparative study between two protocols used to treat the post-operative pain in pacients that underwent (LAUP) Estudo comparativo entre dois protocolos utilizados para tratamento da dor pós-operatória em pacientes submetidos a uvulopalatoplastia assistida por laser (LAUP)  

Microsoft Academic Search

One of the limiting factors for surgical procedures of palate in the treatment of sleep apnea and snore is the occurrence of excruciating pain. Among the procedures used there are those that provoke term-abrasion to obtain palatal ressection. These methods, including the laser tends to be quite painful, demanding the more variables therapeutic interventions. However, there are no evidences that

Serra Carapina; Espírito Santo

2007-01-01

452

Contrôle structural du partage de Rb entre fluide et micas potassiques dans les pegmatites du Brásil Structural control of the Rb distribution between K-micas and fluid in Brazil pegmatites  

NASA Astrophysics Data System (ADS)

A geochemical study of pegmatitic micas from Minas Gerais State in Brazil was performed with an electron microprobe, in order to examine the variations of Rb, K, Al and F contents. It is observed a linear decreasing relationship between the [Rb/K] ratio of the micas and their contents in Al VI. The interpretation is based on the hypothesis that the partition coefficient CRb/Kmica/fl between fluid and mineral does not vary significantly as a function of temperature and pressure in the narrow conditions of crystallization of pegmatites. It is suggested that the relation: CRb/Kmica/fl=0.55×(5-[Al VI]) is of crystallochemical order. Micas with low contents in Al take higher contents in Rb because the potassic sites where Rb enters are larger. This relation gives another way of calculating the values [Rb/K] of the fluids knowing Rb, K, Al and Si in the micas. This crystallochemistry also allows us to foresee a direct correlation between Rb and F in the pegmatitic micas. To cite this article: J. Quéméneur et al., C. R. Geoscience 336 (2004).

Quéméneur, Joël; Volfinger, Marcel; Azevedo, Luciana

2004-02-01

453

AssociaÁªo entre Ìndice de ventilaÁªo e tempo de ventilaÁªo mec‚nica em lactentes com bronquiolite viral aguda Association between ventilation index and time on mechanical ventilation in infants with acute viral bronchiolitis  

Microsoft Academic Search

Objective: To evaluate the association between time on mechanical ventilation and anthropometric, clinical and pulmonary function variables, measured early, in infants on invasive mechanical ventilation with acute respiratory failure due to viral bronchiolitis, and the temporal progression of variables with significant correlations. Methods: Twenty-nine infants admitted to the pediatric intensive care unit of UNICAMP university hospital were studied. Acute viral

Armando A. Almeida-Jœnior; Marcos T. N. da Silva; C. B. Almeida; Breno M. Nery; D. Ribeiro

2005-01-01

454

Estudo polarografico sobre a formacao de complexos entre indio (III) e azoteto de sodio, em meio aquoso. (Polarographic study about the complex formation between indium (III) and sodium azide, in aqueous media).  

National Technical Information Service (NTIS)

The present work is a branch of the main work concerned with the complex formation between several metal cations and azide ligand in aqueous media. The polarographic behavior of indium in azide system showed the tendency of complexation. Using polarograph...

R. Tokoro M. Bertotti

1988-01-01

455

Changes in concentration–discharge regression parameters due to coal mining and reclamation activities \\/ Changements dans les paramètres de régression entre concentration et débit, causés par l’exploitation minière de charbon et des activités de reconversion  

Microsoft Academic Search

Assessment of the impacts of mining and reclamation, and design of management practices to reduce chemical loads in stream channels, require knowledge of changing hydrological conditions and of changing sources and rates of release of chemicals into stream waters. One simple method for evaluating these impacts is to combine flow duration curves with regression relations between surface-water chemical concentrations (C)

James V. Bonta

2005-01-01

456

Positive Prevention: Successful Approaches To Preventing Youthful Drug and Alcohol Use [and] La Prevencion Positiva: Metodos que han tenido exito en la prevencion del uso de drogas y alcohol entre la juventud.  

ERIC Educational Resources Information Center

The United States has the highest rate of youthful drug abuse of any industrialized country in the world. There is a growing awareness that drug and alcohol use are closely connected to other problems such as teenage suicide, adolescent pregnancy, traffic fatalities, juvenile delinquency, poor school performance, runaways, and dropouts. Youthful…

American Association of School Administrators, Arlington, VA.

457

La Desercion Escolar en los Niveles de Sexto y Noveno Grado: Una Comparacion Entre Zonas Rurales y Urbanas. Boletin 219 (The Educational Desertion in the 6th and 9th Grades: A Comparison Between Rural and Urban Zones. Bulletin 219).  

ERIC Educational Resources Information Center

In 1962 and again in 1965, a group of sixth and ninth grade students in selected schools in four Puerto Rican communities were interviewed to investigate the factors influencing students' decision to withdraw from school before completing twelfth grade and to identify some characteristics of dropouts. Of 616 students interviewed in 1962, 20.9% of…

Lopez, Maria I. Hernandez; And Others

458

RELACION ENTRE CARACTERISTICAS DEL TRACTO DIGESTIVO Y LOS HABITOS ALIMENTARIOS DE PECES DEL RIO YUCAO, SISTEMA DEL RIO META (COLOMBIA) RELATIONSHIP BETWEEN DIGESTIVE TRACT CHARACTERISTICS AND DI ETS OF FISHES FROM YUCAO RIVER, META RIVER SYSTEM (COLOMBIA)  

Microsoft Academic Search

Stomach contents of 21 species of fishes catched in two sites of Yucao river on different periods of the year were analyzed. Digestive structures were classified according to the mouth position, stomach and teeth form, intestine length and gill rakers number. These characteristics were related with generalized four food habits: detritivorous, herbivorous, periphyton feeders and omnivorous. Teeth and stomach shapes

René M. Sánchez; Germán Galvis; Pedro F. Victoriano

459

Como ayudar a su hijo durante los primeros anos de la adolescencia: Para los padres con ninos entre las edades de 10 a 14 anos (Helping Your Child through Early Adolescence: For Parents of Children from 10 through 14).  

ERIC Educational Resources Information Center

Recognizing that parents and families can greatly influence the development of their 10- through 14-year-olds, this Spanish-language booklet is part of a national effort to provide parents with the latest research and practical information to help them support their children both at home and in school. The booklet is organized in 13 sections…

Paulu, Nancy

460

Dependance de la production de photons durs avec le parametre d'impact dans les collisions entre ions lourds aux energies intermediaires. (Relation between hard photon production and impact parameter in heavy ion collisions at intermediate energies).  

National Technical Information Service (NTIS)

Hard photons produced in heavy-ions collisions at intermediate energies have been used in order to study hot and compresses nuclear matter created in these collisions (at Ganil). It was found that Bremsstrahlung radiation emitted in np collisions is the m...

G. Martinez Garcia

1994-01-01

461

Fundamental Trends in the Evolution of Relations between Employers, Workers and Governments in Africa (Tendances Fondamentales de l'Evolution des Relations entre Employeurs, Travailleurs et Gouvernements en Afrique).  

National Technical Information Service (NTIS)

A panoramic survey is made of the fundamental tendencies prevailing in the relations between employers, workers, and public authorities in the African countries which have just attained independence. There would appear to be not so much a question of bett...

C. Bokonga

1971-01-01

462

The Trade-off between Inflation and Unemployment: A Survey of the Econometric Evidence for Selected Countries (La relation inverse entre l'inflation et le chômage: une analyse des résultats empiriques dans certains pays sélectionnés) (Relación de correspondencia entre la inflación y el desempleo: estudio de las pruebas econométricas para países seleccionados)  

Microsoft Academic Search

Il s'est avéré très difficile, dans de nombreux pays, de concilier le plein emploi et la stabilité des prix. A en juger d'après les expériences antérieures, les responsables de la politique économique se heurtent au dilemme d'une relation inverse: les efforts pour accroître la production et l'emploi en augmentant le volume de la demande globale ont habituellement pour effet d'accroître

Morris Goldstein

1972-01-01

463

Phytoreovirus-like sequences isolated from salivary glands of the glassy-winged sharpshooter Homolodisca vitripennis (Hemiptera: Cicadellidae)  

SciTech Connect

The salivary glands of the Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis Germar 1821, (syn. H. coagulata, Hemiptera: Cicadellidae) were collected and used to produce a cDNA library. Examination by BLASTX analyses identified 2 viral sequences, one a 610-base pair fragment and a second 839-base pair fragment, both of which had significant homology to viruses within the genus Phytoreovirus. Resequencing of the fragments confirmed sequence validities. These sequences were used for in silico protein translation and BLASTP analysis confirming the established homology. While the GWSS is the primary vector of Pierce's disease of grapes, this is the first report that GWSS may be a vector of a phytoreoviruses. Phylogenetic and homology comparisons with BLASTX, BLASTP, and PAUP analyses indicated that the viral sequences isolated from GWSS were closely related to the viruses in the Family Reoviridae, Genus Phytoreovirus, specifically Rice Dwarf Phytoreovirus (RDV). RDV is the only plant reovirus that is not limited to the phloem. Phytoreoviruses are transmitted in a propagative manner by cicadellid leafhoppers (Hemiptera: Cicadellidae), which acquire and transmit them during feeding. Phytoreoviruses have been reported from Agallian, Agalliopsis, Nephotettix, and Recilia, genera of leafhoppers, with evidence for transovarial transmission. The GWSS, although considered to feed primarily from the xylem, ingests from other plant tissues, such as the phloem and mesophyll during probing similar to other leafhoppers. The feeding behavior and wide host range of the GWSS provides an overlapping condition for these two organisms, leafhopper and virus. GWSS will feed from grasses as a transitory host, and on herbaceous and woody plants as primary hosts, which may favor the acquisition and transmission of Phytoreovirus by this leafhopper. Monitoring for an increase of Phytoreovirus spread in graminaceous crops that are in proximity to vineyards or tree crop orchards, where GWSS occurs, such as in southern California, will provide a better understanding of the potential role of the GWSS as a disease vector in the spread of phytoreoviruses and other plant pathogens. The sequences have been deposited in NCBI database under the accession numbers (EF058280) for GWSS-V1, WHSg013C11 and (EF058281) for GWSS-V2, WHSg024H02. (author) [Spanish] Dos fragmentos de 610 y 839 pares de bases fueron aislados apartir de una genoteca de expresion derivada de las glandulas salivales del cucarron de las alas cristalinas (GWSS), Homalodisca vitripennis, Germar 1821 (syn. H. coagulata) el cual es vector de la enfermedad de Pierce de las uvas. Los resultados de alineamiento utilizando BLASTX, BLASTP y el analisis filogenetico utilizando PAUP indicaron que los fragmentos de DNA estaban relacionado de manera mas cercana a viruses en la familia Reoviridae, genero Phytoreovirus, y especificamente a los virus del enanismo del arroz (RDV) y al virus del tumor de las grietas (WTV). El cucarron de las alas cristalinas es un saltahoja que se alimenta no solo del xilema sino tambien del floema y del mesofilo. Saltahojas del genero Agallian, son los principales vectores de WTV, el cual infecta el floema de plantas dicotiledoneas tumoraciones en las hojas y en las raices. WTV es transmitido por saltahojas y es el unico reovirus que es capaz de infectar tanto tejidos del xilema como del floema. El comportamiento alimentario del GWSS y su amplio rango de hospederos que incluye pastos y plantas herbaceas y lenosas podria proveer la interaccion entre estos dos organismos facilitando la adquisicion y tranmision de fitoreovirus por el GWSS. Un adecuado monitoreo de el incremento en la expansion de reoviruses en cultivos de gramineas asociados al los vinedos en donde GWSS ocurre en regiones tales como el sur de California, y en general el sur de los Estados Unidos, podria proveer un mejor entendimiento del papel del GWSS como vector de fitoreovirus y otros patogenos de plantas. Las sequencias se depositaron en la base de datos NCBI con los siguientes numeros de identificac

Katsar, C.S.; Hunter, W.B. [Subtropical Insect Research Unit, United States Horticultural Research Lab, United States Department Agriculture, ARS, Fort Pierce, FL 34945 (United States)]. E-mail: Whunter@ushrl.ars.usda.gov; Sinisterra, X.H. [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States)

2007-03-15

464

Efecto de la irradiación luminosa en la aclimatación de Mammillaria carmenae Castañeda (Cactaceae) proveniente de cultivo in vitro  

Microsoft Academic Search

Resumen Se reprodujo Mamillaria carmenae por cultivo in vitro a partir de areolas de una planta etiolada in vivo. Se obtuvieron plantas a partir de callos, las cuales se aclimatizaron bajo diferentes tratamientos de irradiación luminosa (50, 150 y 970 µmol m -2 s -1 ) bajo condiciones de invernadero. Durante la acli- matación se registraron la variación en el

Coca Soriano; Ortiz Montiel; Juan Gerardo; Sánchez Correa; Pérez Crisanto Joel

465

O consumo de alimentos derivados de organismos geneticamente modificados e a saúde humana e animal  

Microsoft Academic Search

A transformação genética de plantas é uma ferramenta extraordinária da biotecnologia, que permite o aumento da produtividade dos cultivos e a melhoria da qualidade nutricional dos alimentos. Ela também permite expandir o uso das plantas para áreas até hoje inexploradas, como a síntese de produtos em biofábricas. Muitos alimentos consumidos atualmente já são produzidos - totalmente ou em parte -

Marcelo Gravina de Moraes

466

Carbon Isotope Composition as a Tool to Characterize the Photosynthetic Mechanism of Herbs, Spices, and Medicinal Plants  

Microsoft Academic Search

RESUMO: Composição isotópica de carbono como ferramenta para caracterizar o mecanismo fotossintético de plantas medicinais, aromáticas e condimentares. O fracionamento isotópico é um teste simples para caracterizar vias fotossintéticas. Informações dos mecanismos fotossintéticos das plantas são importantes na introdução e cultivo de qualquer espécie, e neste caso específico, para espécies medicinais e aromáticas exóticas e selvagens. Um uso potencial para

José Abramo Marchese; Lin Chau Ming; Carlos Ducatti; Fernando Broetto; Evandro Tadeu da Silva; Marcelo Leonardo; Juliano Toniato

467

Uvby-B Photometry of High Velocity Stars. Photometric Parallaxes and Preliminary Kinematic Results  

NASA Astrophysics Data System (ADS)

RESUMEN. Se han explorado dos metodos para la determinaci6n de paralajes fotometricos usando fotometrfa uv - . Estos metodos dependen de las relaciones estandar de Crawford (1975) y de Olsen (1984) y de colores y magnitudes sinteticas de VandenBerg y Bell (1985). Ambos metodos incluyen una correcci6n evolucionaria de forma f6c0. Se calculan las distancias para las 711 estrellas de alta velocidad y pobres en metales en el catalogo uvby-p de Schuster y Nissen (1988). Se comparan estas con las distancias de Sandage y Fouts (1987) y Laird, Carney y Latham (1988) para las estrellas en comtfin. Tambien son aplicables nuestros metodos a estrellas de paralaje. En general las comparaciones son satisfactorias y las sistematicas son despreciables o pequefias. Las distancias finales de nuestras 711 estrellas se aplican a un numero de problemas cinematicos. Se estudian algunos diagramas interesantes, tales como el diagrama de energia de Toomre y el diagrama V(rot) versus [Fe/H]. ABSTRACT Two methods for the determination of parallaxes using uvbyP photometry are being explored. These methods depend upon the standard relations of Crawford (1975) and of Olsen (1984) and upon synthetic colors and magnitudes of VandenBerg and Bell (1985). Both include an evolutionary correction of the form f6c0. Distances are calculated for the 711 high-velocity and metal-poor stars in the uvby-P catalogue of Schuster and Nissen (1988). These are compared to the distances of Sandage and Fouts (1987) and Laird, Carney, and Lathain (1988) for stars in common. Also our methods are applied to parallax stars. In general the comparisons are good with negligible or small systematic differences. The final distances of our 711 stars are applied to a number of kinematical problems. Several interesting diagrams are studied, sucl as Toomre energy diagram and the plot of V(rot) versus [Fe/H]. Key words: DISTANCES - PHOTOMETRY - STARS-POPULATION II

Schuster, W. J.

1990-11-01

468

La distribución de objetos en el Cinturón de Kuiper y la posible existencia de un nuevo planeta en el Sistema Solar  

NASA Astrophysics Data System (ADS)

A pesar de que la capacidad observacional no lo limita, no se han descubierto objetos en el Cinturón de Kuiper más allá de las 50 AU. Recientemente, hemos propuesto que un embrión planetario originalmente formado en la región de Urano-Neptuno, y posteriormente migrado hacia distancias mayores a 50-60 AU, puede explicar este hecho. Presentamos simulaciones numéricas de acreción del Sistema Solar exterior que muestran cómo, naturalmente, podriamos esperar que un planeta de este tipo se encuentre actualmente en regiones distantes del sistema solar. Analizamos además la posibilidad de detectarlo con instrumentos actuales.

Brunini, A.

469

Boletín del Instituto Nacional del Cáncer  

Cancer.gov

No se puede negar que vivimos en una comunidad global, en la que los eventos de una ciudad o país pueden tener graves consecuencias para los residentes de otra ciudad o país a miles de kilómetros de