980 resultados para 2,4-dichlorophenoxyacetic acid


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The potent antimicrobial compound 2,4-diacetylphloroglucinol (DAPG) is a major determinant of biocontrol activity of plant-beneficial Pseudomonas fluorescens CHA0 against root diseases caused by fungal pathogens. The DAPG biosynthetic locus harbors the phlG gene, the function of which has not been elucidated thus far. The phlG gene is located upstream of the phlACBD biosynthetic operon, between the phlF and phlH genes which encode pathway-specific regulators. In this study, we assigned a function to PhlG as a hydrolase specifically degrades DAPG to equimolar amounts of mildly toxic monoacetylphloroglucinol (MAPG) and acetate. DAPG added to cultures of a DAPG-negative DeltaphlA mutant of strain CHA0 was completely degraded, and MAPG was temporarily accumulated. In contrast, DAPG was not degraded in cultures of a DeltaphlA DeltaphlG double mutant. To confirm the enzymatic nature of PhlG in vitro, the protein was histidine tagged, overexpressed in Escherichia coli, and purified by affinity chromatography. Purified PhlG had a molecular mass of about 40 kDa and catalyzed the degradation of DAPG to MAPG. The enzyme had a kcat of 33 s(-1) and a Km of 140 microM at 30 degrees C and pH 7. The PhlG enzyme did not degrade other compounds with structures similar to DAPG, such as MAPG and triacetylphloroglucinol, suggesting strict substrate specificity. Interestingly, PhlG activity was strongly reduced by pyoluteorin, a further antifungal compound produced by the bacterium. Expression of phlG was not influenced by the substrate DAPG or the degradation product MAPG but was subject to positive control by the GacS/GacA two-component system and to negative control by the pathway-specific regulators PhlF and PhlH.

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The performance of Pseudomonas biocontrol agents may be improved by applying mixtures of strains which are complementary in their capacity to suppress plant diseases. Here, we have chosen the combination of Pseudomonas fluorescens CHA0 with another well-characterized biocontrol agent, P. fluorescens Q2-87, as a model to study how these strains affect each other's expression of a biocontrol trait. In both strains, production of the antimicrobial compound 2,4-diacetylphloroglucinol (DAPG) is a crucial factor contributing to the suppression of root diseases. DAPG acts as a signaling compound inducing the expression of its own biosynthetic genes. Experimental setups were developed to investigate whether, when combining strains CHA0 and Q2-87, DAPG excreted by one strain may influence expression of DAPG-biosynthetic genes in the other strain in vitro and on the roots of wheat. DAPG production was monitored by observing the expression of lacZ fused to the biosynthetic gene phlA of the respective strain. Dual-culture assays in which the two strains were grown in liquid medium physically separated by a membrane revealed that Q2-87 but not its DAPG-negative mutant Q2-87::Tn5-1 strongly induced phlA expression in a DeltaphlA mutant of strain CHA0. In the same way, phlA expression in a Q2-87 background was induced by DAPG produced by CHA0. When coinoculated onto the roots of wheat seedlings grown under gnotobiotic conditions, strains Q2-87 and CHA0, but not their respective DAPG-negative mutants, were able to enhance phlA expression in each other. In summary, we have established that two nonrelated pseudomonads may stimulate each other in the expression of an antimicrobial compound important for biocontrol. This interpopulation communication occurs in the rhizosphere, i.e., at the site of pathogen inhibition, and is mediated by the antimicrobial compound itself acting as a signal exchanged between the two pseudomonads.

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Artikkeli sisältää Sosiologipäivien 22 työryhmäraporttia sosiologian eri aloilta

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Eighty-Sixth General Assembly Senate Code of Ethics (Senate Resolution 4-Adopted 2-4-2015)Every legislator owes a duty to uphold the integrity and honor of the general assembly, to encourage respect for the law and for the general assembly and the members thereof, and to observe the legislative code of ethics.

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Eighty-Sixth General Assembly Joint Rules Governing Lobbyists (House Concurrent Resolution 7) House Adopted 2-3-2015, Senate Adopted 2-4-2015

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Eighty-Sixth General Assembly House Rules (House Resolution 4-Adopted 2-3-2015)

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Opinnäytetyömme on kirjallisuuskatsaus hankkeeseen Musiikki ja draama lapsen kivun ja pelon lievittäjänä. Opinnäytetyömme tarkoituksena on ollut kartoittaa tutkittua tietoa 2 - 4-vuotiaan lapsen ilmaisukeinoista, jotka koemme hyödyllisiksi lapsen ja sairaanhoitajan vuorovaikutusta ajatellen. Työssämme olemme soveltaneet systemaattinen kirjallisuuskatsauksen metodia aineiston hankinnassa. Olemme koonneet opinnäytetyömme aineiston tekemällä hakuja sosiaali- ja terveysalan tietokannoista. Valitun aineiston piti täyttää asettamamme kriteerit. Artikkeleiden tuli olla julkaistu vuosina 2004-2007 ja niiden tuli olla tieteellisiä julkaisuja. Artikkeleiden piti myös vastata tutkimuskysymykseemme: kuinka 2 - 4-vuotias lapsi ilmaisee itseään. Opinnäytetyö on jäsennetty teemoittain aineistosta nousseiden ilmaisukeinojen mukaan. Keskeinen käsite työssämme on leikki-ikäinen lapsi, tarkoittaen tällä ikävuosia 2 - 4. Käsittelemme tuloksissa lapsen ilmaisukeinoina puhetta, leikkiä, piirtämistä ja eleitä. Piirtäminen on nopea, halpa sekä helppo kommunikoinnin väline. Leikin kautta lapsi oppii käsittelemään tunteitaan rakentavasti ja emotionaalisen kehityksen kannalta on tärkeää, että lapsi saa ilmaista tunteitaan. Kielen ja puheen kehitys on kiinteässä yhteydessä varhaisen vuorovaikutuksen kanssa. Kuukausia ennen kuin lapset tuottavat sanoja, he käyttävät eleitä asiansa ilmaisemiseen. Hoitajan tulisi työssään ottaa perhe- ja lapsilähtöinen työskentelyote. Hoitajan käyttäessä lapsen kehitystason mukaista kieltä sekä ikätasolle sopivia vaihtoehtoisia keinoja kuten leikkiä apunaan, pysyy lapsen stressitaso hallittavissa. Ennen kuin lapsi oppii kielelliset taidot ilmaista itseään, on hänellä käytössään vaihtoehtoisia menetelmiä tunteidensa sekä ajatustensa esille tuomiseen. Kun hoitaja on perillä lapsen oletetusta kyvystä ilmaista itseään, voi myös hoitaja ilmaista itseään niin, että lapsi tämän ymmärtää.

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O objetivo deste trabalho foi avaliar os efeitos do biorregulador MBTA [cloridrato de N,N-dietil-2-(4-metilbenziloxi) etilamina] aplicado em diferentes épocas e concentrações na produtividade e qualidade dos frutos da laranjeira 'Pêra'. Em duas safras consecutivas, o MBTA foi aplicado em três diferentes concentrações (8; 16 e 32 mg L-1) e em duas diferentes fases fenológicas (25% e 100% de flores abertas), em árvores cítricas adultas, utilizando um volume de 7 litros de solução por planta, acompanhado do adjuvante Silwett L-77 0,05%. Foram amostrados 20 frutos por planta, em quatro diferentes épocas estudadas, para determinar o teor de sólidos solúveis (SS); acidez titulável (AT); quantidade de sólidos solúveis por caixa de 40,8 kg; pH; rendimento de suco; "ratio" (relação SS/AT), e a massa média dos frutos. Os efeitos do MBTA variaram de acordo com a concentração aplicada e com a fase fenológica de aplicação. O MBTA, na concentração de 8 mg L-1, aplicado com 25% das flores abertas, incrementou o teor de sólidos solúveis, a acidez, a quantidade de sólidos solúveis por caixa de 40,8 kg e a produtividade. Esse mesmo tratamento também reduziu a massa média dos frutos e não alterou o rendimento de suco e o "ratio" do suco dos frutos. O incremento médio foi de 0,49 a 0,65% na concentração de sólidos solúveis, de 0,11 a 0,13 kg na quantidade de sólidos solúveis por caixa de 40,8 kg e de 20,4 kg/planta na produtividade.

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(S)-2-(4-Bromo-2,4"-bithiazole)-1-(tert-butoxycarbonyl)pyrrolidine ((S)-1) was obtained as a single enantiomer and in high yield by means of a two-step modified Hantzsch thiazole synthesis reaction when bromoketone 3 and thioamide (S)-4 were used. Further conversion of (S)-1 into trimethyltin derivative (S)-2 broadens the scope for further cross-coupling reactions.

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A synthetic route to enantiopure cis-2,4-disubstituted and 2,4-bridged piperidines is reported, the key step being a stereoselective conjugate addition of an organocuprate to a phenylglycinol-derived unsaturated lactam bearing a substituent at the 8a-position.