966 resultados para Grass flower


Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE: The prevalence of ragweed allergy is increasing worldwide. Ragweed distribution and abundance is spreading in Europe in a wide area ranging from the Rhone valley in France to Hungary and Ukraine, where the rate of the prevalence can peak at as high as 12%. Low-grade ragweed colonisation was seen in Geneva and Ticino, less than two decades ago. There were fears that allergies to ragweed would increase Switzerland. The intent of this study was to assess the rate of prevalence of sensitisation and allergy to ragweed in the population living in the first rural Swiss setting where ragweed had been identified in 1996, and to evaluate indirectly the efficacy of elimination and containment strategies. MATERIAL AND METHODS: In 2009, 35 adults in a rural village in the Canton of Geneva were recruited. Data were collected by means of questionnaires and skin-prick tests were done on each participant. The study was approved by the local Ethics Committee. RESULTS: Based on questionnaires, 48.6% had rhinitis (95% confidence interval [CI] 32.9-64.4; n = 17/35) and 17.1% asthma (95% CI 8.1-32.6; n = 6/35). Atopy was diagnosed in 26.4% (95% CI 12.9-44.4) of the sample (n = 9/34). Ragweed sensitisation was found in 2.9% (95% CI 0.7-19.7; n = 1/34), mugwort sensitisation in 2.9% (95% CI 0.1-14.9; n = 1/35), alder sensitisation in 17.1% (95% CI 6.6-33.6; n = 6/35), ash sensitisation in 12.5% (95% CI 3.5-29.0; n = 4/32) and grass sensitisation in 22.9% (95% CI 10.4-40.1; n = 8/35). Ragweed (95% CI 0.1-14.9; n = 1/34) and mugwort allergies (95% CI 0.1-14.9; n = 1/35) were both found in 2.9% of the population. CONCLUSION: This study showed a surprisingly low incidence of ragweed sensitisation and allergy, of 2.9% and 2.9%, respectively, 20 years after the first ragweed detection in Geneva. The feared rise in ragweed allergy seems not to have happened in Switzerland, compared with other ragweed colonised countries. These results strongly support early field strategies against ragweed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Certain strains of Pantoea are used as biocontrol agents for the suppression of plant diseases. However, their commercial registration is hampered in some countries because of biosafety concerns. This study compares clinical and plant-beneficial strains of P. agglomerans and related species using a phenotypic analysis approach in which plant-beneficial effects, adverse effects in nematode models, and toxicity were evaluated. Plant-beneficial effects were determined as the inhibition of apple fruit infection by Penicillium expansum and apple flower infection by Erwinia amylovora. Clinical strains had no general inhibitory activity against infection by the fungal or bacterial plant pathogens, as only one clinical strain inhibited P. expansum and three inhibited E. amylovora. By contrast, all biocontrol strains showed activity against at least one of the phytopathogens, and three strains were active against both. The adverse effects in animals were evaluated in the plant-parasitic nematode Meloidogyne javanica and the bacterial-feeding nematode Caenorhabditis elegans. Both models indicated adverse effects of the two clinical strains but not of any of the plant-beneficial strains. Toxicity was evaluated by means of hemolytic activity in blood, and genotoxicity with the Ames test. None of the strains, whether clinical or plant-beneficial, showed any evidence of toxicity

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Most aerial parts of the plants are covered by a hydrophobic coating called cuticle. The cuticle is formed of cutin, a complex mixture of esterified fatty acids that are embedded and associated with waxes. The cuticle often appears as a superposition of layers of different composition: The cuticle proper formed of cutin and a mixture of waxes and underneath, the cuticle layer containing cutin, intracuticular waxes and polysaccharides of the cell wall. In addition to its involvement in plant development by preventing organ fusions, the cuticle acts as a barrier to prevent water loss and protect plants against environmental aggressions such as excessive radiation or pathogens attacks. PEC1/AtABCG32 is an ABC transporter from the PDR family involved in cutin biosynthesis. Characterization of the peci mutant in Arabidopsis thaliana showed that PEC1 plays a significant role in the diffusion barrier formation in leaves and petals. The cuticles of leaves and flowers of peci are permeable and the cuticular layer rather than the cuticular proper was altered in the petals, underlining the importance of this particular layer in the maintenance of the diffusion barrier. Chemical analysis on the flower cutin monomer composition of ped mutant revealed a decrease in hydroxylated cutin monomers, suggesting a function of PEC1 in the incorporation of these monomers in the polymer cutin. However, the exact nature of the substrates of PEC1 remained elusive. PEC1 homologues in barley and rice, respectively HvABCG31/EIBI1 and OsABCG31, are also implicated in cuticle biosynthesis. Interestingly, the rice mutant displays more severe phenotypes such as dwarfism and spreading necrosis conducting to the seedling death. In this work, we further characterized osabcg31 mutant and hairpin-RNAi downregulated OsABCG31 plant lines showing reduced growth and cuticle permeability. Our analysis showed a decrease in hydroxylated cutin monomers and severe disruptions in the cuticle, which explain the permeability. Further insights into the function of the cuticle in rice resistance/susceptibility to Pathogens were obtained after inoculation with Magnaporthe oryzae, the fungus responsible for the rice blast disease. Osabcg31 as well as the transgenic lines downregulating OsABCG31 showed increased resistance to the fungus. However, only later steps of infection are reduced . and no impact is obseived on the germination or penetration stages, suggesting that the cuticle disruption per se is not responsible for the resistance. We further investigated the cause of the resistance by analyzing the expression of defense related gene in osabcg31 prior to infection. We found that osabcg31 constitutively express defense related genes, which may explain the resistance, the dwarfism and the cell death. osabcg31 is thus a tool to study the connection between cuticle, plant development and defense signaling networks in rice. The transport function of PEC1 family members is still unknown. In order to link cutin biosynthesis and transport activity, we combined ped mutation with mutations in cutin synthesis related genes. Here, we show that PEC1 acts independently from GPAT4 and GPAT8 pathway and partially overlaps with GPAT6 biosynthesis pathway that leads to the production of hydroxylated C16 cutin precursor 2-Mono(10,16-dihydroxyhexadecanoylJglycerol (2-MHG). In addition, we noticed that despite a comparable cutin monomer composition, ped mutant leaves cuticle are permeable while that of gpat6 mutant are not. This finding raises the possibility of PEC1 being required for the incorporation of C16 hydroxylated monomers and their structural arrangement rather than their direct transport towards the cuticle. A careful investigation of the cuticle permeability, cutin composition and ultrastructure during leave development in Wt plants and ped mutants revealed a possible different regulation of several pathways of cutin biosynthesis and showed the importance of PEC1 function early during leave cuticle maturation. In order to elucidate the transport activity of PEC1, we successfully expressed PEC1 in Nicotiana benthamiana plant system for direct transport experiments. This system will be used to test the PEC 1-dependent transport of potential substrates such as sn-2-monoacylglycerol loaded with a hydroxylated C16 fatty acid. -- Toutes les parties aériennes des plantes sont recouvertes d'une couche hydrophobe appelée «cuticule». Cette cuticule est composée de cutine, un polymère d'acides gras estérifiés, et de cires. La cuticule apparaît souvent sous forme de couches superposées: une première couche extérieure appelée «cuticle proper» formée de cutine et d'un mélange de cires, et une deuxième couche, la «cuticle layer», formée de cutine associée à des cires intracuticulaires et des polysaccharides pariétaux. La cuticule joue le rôle de barrière prévenant contre la perte d'eau et les agressions environnementales. AtABCG32/PEC1 est un transporteur ABC de la famille des PDR impliqué dans la synthèse de la cutine. L'étude du mutant peci d'Arabidopsis thaliana a révélé une fonction de PEC1 dans la formation de la barrière de diffusion. La cuticule des feuilles et fleurs de peci est perméable. Des altérations de la «cuticle layer» ont été démontrées, soulignant son importance dans le maintien de la barrière. L'analyse de la composition de la cutine de peci a montré une réduction spécifique en monomères hydroxylés, suggérant un rôle de PEC1 dans leur incorporation dans la cuticule. Cependant, la nature exacte des substrats de PEC1 n'a pas été identifiée. PEC1 possède deux homologues chez l'orge et le riz, respectivement HvABCG31 et OsABCG31, et qui sont impliqués dans la biosynthèse de la cuticule. Chez le riz, des phénotypes plus sévères ont été observés tels que nanisme et nécroses conduisant à la mort des jeunes plants. Dans cette étude, nous avons continué la caractérisation de osabcg31 ainsi que des lignées de riz sous exprimant le gène OsABCG31 et présentant une cuticule perméable tout en ayant une meilleure croissance. Notre étude a démontré une réduction des monomères hydroxylés de cutine et une désorganisation de la structure de la cuticule, aggravée dans le mutant osabcg31. Ce résultat explique la perméabilité observée. Des mformations P|us approfondies sur l'implication de la cuticule dans la résistance aux pathogènes ont été obtenues après inoculation du mutant osabcg31 et les lignées sous- exprimant OsABCG31 avec une souche virulente de Magnaporthe Oryzae, le champignon responsable de la pyriculariose du riz. Les différentes lignées testées ont démontré une résistance au pathogène. Cependant, seules les étapes tardives de l'infection sont réduites et aucun impact n'est observé sur la germination des spores ou la pénétration du champignon, suggérant que les modifications de la cuticule ne sont pas directement à l'origine de la résistance. L'analyse de l'expression de gènes impliqués dans la résistance à Magnaporthe.oryzae a mis en évidence l'expression constitutive de ces gènes en l'absence de tout contact avec le pathogène. Ceci explique la résistance, le nanisme et la mort cellulaire observés. Ainsi, osabcg31 représente un outil efficace pour l'étude intégrée des systèmes de régulation de la défense, de développement des plantes et la cuticule. La nature des substrats transportés par PEC1/AtABCG32 reste inconnue. Dans le but d'établir une liaison entre biosynthèse de cutine et transport des précurseurs par PEC1, la mutation peci a été combinée avec des mutants impliqués dans différentes voies de biosynthèse. Cette étude a démontré une fonction indépendante de PEC1 de la voie de biosynthèse impliquant les enzymes GPAT4 et GPAT8, et une fonction partiellement indépendante de la voie impliquant GPAT6 qui mène à la production de précurseurs sn-2- monoacylglycerol chargés en acides gras en C16 (2-MHG). De plus, malgré un profil similaire en monomères de cutine, gpat6 conserve une cuticule imperméable alors que celle de PEC1 est perméable. Ceci suggère que PEC1 est nécessaire à l'incorporation des monomères en C16 et leur arrangement structurel plutôt que simplement à leur transport direct. L'étude approfondie de la perméabilité cuticulaire, de la structure ainsi que de la composition en cutine pendant le développement des feuilles de peci et la plante sauvage a révélé l'existence de différentes régulations des voies de biosynthèses des monomères et a démontré l'importance de PEC1 dans les premières étapes de la mise en place de la cuticule. Pour identifier les substrats transportés, l'expression de PEC1 chez le système hétérologue Nicotiana benthamiana a été conduite avec succès. Ce système sera utilisé pour tester le transport de substrats potentiels tels que le sn-2-monoacylglycerol chargé en acide gras en C16.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the present work, the pH dependent colour change of the crude flower extracts is suggested as subject in teaching chemical or acid-base equilibria, visual indicators and some aspects of spectrophotometric concepts and applications. The vegetal species used are commonly found in Brazil, and the extraction methodology proposed is inexpensive and easy to perform in secondary schools and in general chemistry or instrumental undergraduate courses. A bibliographic review about the use of vegetal extracts in chemical education and a discussion of the flower colour are also presented.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Since barrier protection measures to avoid contact with allergens are being increasingly developed, we assessed the clinical efficacy and tolerability of a topical nasal microemulsion made of glycerol esters in patients with allergic rhinitis. Methods: Randomized, controlled, double-blind, parallel group, multicentre, multinational clinical trial in which adult patients with allergic rhinitis or rhinoconjunctivitis due to sensitization to birch, grass or olive tree pollens received treatment with topical microemulsion or placebo during the pollen seasons. Efficacy variables included scores in the mini-RQLQ questionnaire, number and severity of nasal, ocular and lung signs and symptoms, need for symptomatic medications and patients" satisfaction with treatment. Adverse events were also recorded. Results: Demographic characteristics were homogeneous between groups and mini-RQLQ scores did not differ significantly at baseline (visit 1). From symptoms recorded in the diary cards, the ME group showed statistically significant better scores for nasal congestion (0.72 vs. 1.01; p = 0.017) and mean total nasal symptoms (0.7 vs. 0.9; p = 0.045). At visit 2 (pollen season), lower values were observed in the mini-RQLQ in the ME group, although there were no statistically significant differences between groups in both full analysis set (FAS) and patients completing treatment (PPS) populations. The results obtained in the nasal symptoms domain of the mini-RQLQ at visit 2 showed the highest difference (−0.43; 95% CI: -0.88 to 0.02) for the ME group in the FAS population. The topical microemulsion was safe and well tolerated and no major discomforts were observed. Satisfaction rating with the treatment was similar between the groups. Conclusions: The topical application of the microemulsion is a feasible and safe therapy in the prevention of allergic symptoms, particularly nasal congestion.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Volatile compounds from green and roasted yerba mate were analyzed by gas chromatography/mass spectrometry and the flavor profile from yerba mate beverages was determined by descriptive quantitative analyses. The main compounds tentatively identified in green mate were linalool, alpha-terpineol and trans-linalool oxide and in roasted mate were (E,Z)-2,4-heptadienal isomers and 5-methylfurfural. Green mate infusion was qualified as having bitter taste and aroma as well as green grass aroma while roasted mate was defined as having a smooth, slightly burnt aroma. The relationship between the tentatively identified compounds and flavor must be determined by olfatometric analysis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This research, developed with Apis mellifera honey samples from producers of São Paulo State, Brazil, has the objective of verifying how eucalyptus, wild flower, and orange honey samples would be clustered, based on physicochemical characteristics. All the orange honey samples and some wild flower ones formed distinct groups, thus confirming that the floral source interferes with honey characteristics. Eucalyptus and some of the wild flower honey samples were clustered together because of the great floral source variation in the latter ones. The characteristics that influence sample clustering are acidity and electric conductivity on the X axis, and total sugars and pH on the Y axis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Most of the snakebite incidents in the Amazon region involve Bothrops atrox, whose venom presents the most potent edematogenic and necrotic activities in the genus. This work describes the studies of isolation of the chemical constituents and antiedematogenic activity of the species Peltodon radicans (Lamiaceae), which is used in the treatment of snakebites and scorpion stings in the region. The extracts presented aliphatic hydrocarbons, 3beta-OH,beta-amirin (1), 3beta-OH,alpha-amirin (2), beta-sitosterol (3), stigmasterol (4), ursolic acid (5), 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid (tormentic acid, 6), methyl 3beta-hydroxy,28-methyl-ursolate (7), sitosterol-3-O-beta-D-glucopyranoside (8), and stigmasterol-3-O-beta-D-glucopyranoside (9). The flower extracts presented the higher antiedematogenic activity. This is the first report on the study of the flowers, stem, and roots of this plant.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Invocatio: Q.F.F.Q.E.J.S.S.T.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Invocatio: I.N.J.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Biogenic silica is used to describe compounds of hydrated silica (SiO2.nH2O), with specific shapes and sizes, deposited in plants. The chemical composition of biogenic silica and its stability in Jaraguá grass was studied in increasing concentration of NaOH. The analytical results demonstrated high concentration of Si, Al, Fe, Mg, P and low of Cu, Cd and Zn in the phytoliths composition. The silica bodies stability in NaOH solution with increasing concentration was different among the shapes and sizes. Silicified stomata and silicified plant tissues were dissolved along with the dumbbells because they are the less stable forms of biogenic silica.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chromatographic analysis of flavonoids in ethyl acetate fractions of the stamen, gynoecium, and petal of Magnolia grandiflora L. by HPLC-PDA-MS/MS-ESI in the negative ionization mode was performed in this study. The results revealed the presence of eight flavonoids: apigenin 8-C-glucoside, luteolin 8-C-glucoside, quercetin 3-O-rutinoside, quercetin 3-O-galactoside, quercetin, 3-O-glucoside, kaempferol 3-O-rutinoside, isorhamnetin 3-O-glucoside, and isorhamnetin. Their quantification revealed that luteolin 8-C-glucoside is the major flavonoid and that the total phenolic content is concentrated primarily in the stamen. The antioxidant and hepatoprotective effects of ethanolic extract of the flower organs were evaluated against hepatotoxicity induced by CCl4, compared with the effects of silymarin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Elephant grass ash (EGA) was produced at 700 °C, with two different treatments: hot water (EGAhw) or acid solution (EGAas). The efficiency of the treatments at removing the potassium oxide was evaluated with the aim of using the EGA as a pozzolanic mineral addition for cement-based composites. Characterizations were carried out by X-ray fluorescence (XRF), X-ray diffraction (XRD), pozzolanic activity by electric conductivity and application of the kinetic-diffusive model. The analysis evidenced that the chemical treatment was more efficient for removing potassium oxide. The pozzolanic activity test and the kinetic parameters for the EGAas indicated that this ash is suitable for cement-based composites.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tutkimuksessa tarkasteltiin vihreitä arvoja sellun nykyisessä markkinoinnissa ja käsiteltiin lähiajan haasteita markkinoinnin näkökulmasta. Metsäsertifioinnit PEFC ja FSC vaikuttavat sellun markkinointiin, samaten nähtiin ympäristömerkkien olevan voimakkaammin tulossa mukaan sellun liiketoimintaan. Yrityksen suorituskykyä ympäristöasioissa kuvaamaan on kehitetty erilaisia indeksejä. Näissä on jo mukana sellua valmistavia yrityksiä. Lisäksi työssä tarkasteltiin sellua valmistavia yrityksiä.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Studies were conducted in annual crops of strawberry (Fragaria x ananassa) (cv. Elsanta to assess the relative importance of petals as an inoculum source of grey mould, caused by Botrytis cinerea and to identify during which period of flower and fruit development the presence of petals has a significant effect on development of grey mould on fruits. In 1998, the incidence of B. cinerea on flower parts was assessed, and the symptoms of grey mould on fruits were characterised with regards to their starting point. The incidence of B. cinerea on petals was 65-85% of those flowers that harboured B. cinerea. The starting point of symptoms was located underneath the sepals in 65-85% of fruits with grey mould, and petals were present at this site in about 50% of the cases. In 1999, four field experiments were conducted to assess the effect of petal removal at different stages of flower and fruit development on incidence of grey mould. The incidence of grey mould on fruits with petals retained till harvest was circa 55% more than on fruits where petals were removed or had dropped naturally by the end of flowering, regardless of planting date or inoculum level of B. cinerea. The incidence of grey mould was hardly different between treatments where petals were removed at young flower stage, old flower stage, or green fruit stage. It is concluded that petals are an effective and stable source of inoculum for fruit infection by B. cinerea. Considering the high probability that retention of petals during fruit expansion and ripening results in fruit infection, the elimination of petals as an inoculum source appears worthwhile even when the incidence of petal retention on fruits is relatively low.