458 research outputs found

    Preferência de Bemisia tabaci, biótipo B (Hemiptera: aleyrodidae) a genótipos de soja.

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    O objetivo do trabalho foi avaliar a preferência de B. tabaci a 18 genótipos de soja com chance de escolha, em condições de casa de vegetação. Os genótipos avaliados foram: BRI 04-01668, BRI 04-01685, BRI 04-02770, BRI 04-02855, BRI 04-02935, BRI 04-02983, BRS 7860RR, BRS Barreira, BRS Gisele RR, BRS Juliana, BRS Valiosa RR, BRSGO 7960, BRSGO 8060, CD219, CD 215, Emgopa 302RR, IAC 17 e IAC 19. Os materiais com menores infestações de ovos e ninfas foram: BRI 04-01668, BRI 04-01685, BRI 04-02770 e IAC 17 (padrão de resistência) e os mais infestados foram BRS Juliana RR e Emgopa 302RR Os genótipos BRS 7860RR e BRSGO 8060 apresentaram o mesmo perfil de não preferência que IAC19 (padrão de resistência)

    Tumor promoter phorbol myristate acetate inhibits Ca2+ influx through voltage-gated Ca2+ channels in two secretory cell lines, PC12 and RINm5F.

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    Protein kinase C is known to be involved both in initiation and termination of cellular responses due to phosphoinositide breakdown. Here we report that in PC12 cells (a line of neurosecretory cells derived from a rat pheochromocytoma), pretreatment with nanomolar concentrations of phorbol myristate acetate, PMA, which is believed to specifically activate protein kinase C, inhibits the cytosolic-free Ca2+ concentration rise induced by depolarizing agents. In contrast, plasma membrane potential and 45Ca efflux from preloaded cells were unaffected by PMA pretreatment. Inhibition by PMA and diacylglycerol of the cytosolic-free Ca2+ concentration rise induced by depolarization was observed also in another cell line, the insulin secreting line RINm5F. These results raise the possibility that the voltage-gated Ca2+ channel is under inhibitory control by protein kinase C

    Nonlinear Polariton Fluids in a Flatband Reveal Discrete Gap Solitons

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    Phase frustration in periodic lattices is responsible for the formation of dispersionless flat bands. The absence of any kinetic energy scale makes flat band physics critically sensitive to perturbations and interactions. We report here on the experimental investigation of the nonlinear dynamics of cavity polaritons in the gapped flat band of a one-dimensional Lieb lattice. We observe the formation of gap solitons with quantized size and very abrupt edges, signature of the frozen propagation of switching fronts. This type of gap solitons belongs to the class of truncated Bloch waves, and had only been observed in closed systems up to now. Here the driven-dissipative character of the system gives rise to a complex multistability of the nonlinear domains generated in the flat band. These results open up interesting perspective regarding more complex 2D lattices and the generation of correlated photon phases.Comment: 6 pages, 4 figures + supplemental material (6 pages, 6 figures

    Quantificação dos teores de açúcares, oligossacarídeos e amido em genótipos/ cultivares de soja (Glycine Max (L) Merril) especiais utilizados para alimentação humana.

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    RESUMO: Na soja, vários componentes, tais como açúcares, aminoácidos, ácidos orgânicos, sais inorgânicos, isoflavonas e saponinas estão relacionados com o sabor. Os açúcares, a sacarose e o amido, podem melhorar o sabor e a textura da soja. O objetivo deste trabalho foi quantificar os teores desses compostos e dos oligossacarídeos, em sementes de 28 genótipos/cultivares do Banco Ativo de Germoplasma da Embrapa Soja, que apresentam características especiais para o melhoramento genético. Os açúcares e os oligossacarídeos foram quantificados pela técnica de cromatografia liquida de alto desempenho (CLAE) e o amido pela metodologia adaptada de Rickard e Behn (1987). Os genótipos PI 417.159 e F83-8119 apresentaram menores teores de oligossacarídeos totais (2,744 e 3,064 g.100 g de massa seca). As cultivares Tambaguro e Koji Amarela foram as que apresentaram teores de sacarose superiores a 6 g.100 g–1 de massa seca(6,327 e 6,162), enquanto que a única cultivar que apresentou um teor superior a 1 g.100g–1–1 de massa seca de amido foi a Tambaguro (1,191). As cultivares Koji Preta, Tamahomare, Tambaguro e BRS 267 foram estatisticamente superiores quando os 3 atributos (oligossacarídeos totais, sacarose e amido) foram avaliados conjuntamente, com o foco em sabor superior. As cultivares Koji Preta, Tamahomare, Tambaguro foram as melhores fontes genéticas indicadas para cruzamentos, pois não são tropicalizadas, enquanto a cultivar BRS 267 pode melhorar as qualidades sensoriais dos produtos processados a partir de soja. Por outro lado, a cultivar Late Giant, devido ao maior teor de oligossacarídeos, é uma fonte genética em potencial para produção de um alimento funcional à base de soja. ABSTRACT: In soybeans, many components such as sugars, amino acids, organic acids, inorganic salts, saponins and isoflavones are related to the flavour. The sugars, sucrose and starch can improve the soybean flavour and texture. The present study aimed to quantify the contents of these compounds and also the oligosaccharides in the seeds from 28 genotypes/cultivars obtained from the Embrapa Soybean Germplasm Bank, that present special characteristics for genetic improvement programmes. The sugars and oligosaccharides were quantified by high-performance liquid chromatography (HPLC) and the starch by methodology adapted from Rickard e Behn (1987). The genotypes PI 417.159 and F83-8119 showed the lowest contents of total oligosaccharides (2.744 and 3.064 g.100 g DW). The cultivars Tambaguro and Koji Amarela showed sucrose levels above 6 g.100 g–1 DW (6.327 and 6.162), and the only cultivar with a starch content above 1 g.100 g–1 DW was Tambaguro (1.191). The cultivars Koji Preta, Tamahomare, Tambaguro and BRS 267 were statistically better when the 3 attributes (total oligosaccharides, sucrose and starch) were analysed together with a focus on better flavour. The cultivars Koji Preta, Tamahomare, Tambaguro were the best genetic sources for breeding because they have not been tropicalized, whilst the cultivar BRS 267 could improve the sensory qualities of processed soybean-based foods. On the other hand, on account of its higher oligosaccharide content, the cultivar Late Giant is a potential genetic source for the production of functional soybean-based foods

    Evaluation of the Potential of Brazilian Propolis against UV-Induced Oxidative Stress

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    This study investigated the potential use of topically and orally administered propolis extracts to prevent UV irradiation-induced oxidative stress in skin. The results illustrated that green propolis extract (GPE) contained greater amounts of polyphenols, coumaric acid, drupanin, baccharin and artepillin C than did brown propolis extract (BPE). GPE showed higher antioxidant activity than BPE when the IC50 (concentration that caused 50% inhibition) values were compared. Interesting, the oral treatment of hairless mice demonstrated a recovery of 30.0% for GPE and 22.8% for BPE with respect to UV irradiation-induced GSH depletion. The topical pretreatment of animals with both propolis extract solutions recovered around 14.0% of the depleted GSH. However, the employed treatments did not inhibit the increase of cutaneous proteinase secretion/activity caused by irradiation. These findings indicate that despite differences in composition and antioxidant properties, GPE and BPE both successfully prevent UV-induced GSH depletion in vivo and are both promising antioxidant systems against oxidative stress in skin. Based on these findings, complementary studies should be performed to enhance our understanding of the protective effects of propolis extracts in skin

    Mutational and copy number asset of primary sporadic neuroendocrine tumors of the small intestine

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    Small intestine neuroendocrine tumors (SI-NETs) represent the most common histotype among small intestine neoplasms, and metastatic disease is usually present at diagnosis. A retrospective series of 52 sporadic primary surgically resected SI-NETs, which were metastatic at diagnosis, was analyzed by high-coverage target sequencing (HCTS) for the mutational status of 57 genes and copy number status of 40 genes selected from recently published genome sequencing data. Seven genes were found to be recurrently mutated: CDKN1B (9.6%), APC and CDKN2C (each 7.7%), BRAF, KRAS, PIK3CA, and TP53 (each 3.8%). Copy number analysis showed frequent allelic loss of 4 genes located on chromosome 18 (BCL2, CDH19, DCC, and SMAD4) in 23/52 (44.2%) and losses on chromosomes 11 (38%) and 16 (15%). Other recurrent copy number variations were gains for genes located on chromosomes 4 (31%), 5 (27%), 14 (36%), and 20 (20%). Univariate survival analysis showed that SRC gene copy number gains were associated with a poorer prognosis (p = 0.047). Recurrent copy number variations are important events in SI-NET and SRC may represent a novel prognostic biomarker for this tumor type

    Aerobiology of the Wheat Blast Pathogen - Inoculum Monitoring and Detection of Fungicide Resistance Alleles

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    Wheat blast, caused by the ascomycetous fungus Pyricularia oryzae Triticum lineage (PoTl), is mainly controlled by fungicide use, but resistance to the main fungicide groups—sterol demethylase (DMI), quinone outside (QoI), and succinate dehydrogenase inhibitors (SDHI)—has been reported in Brazil. In order to rationalize fungicide inputs (e.g., choice, timing, dose-rate, spray number, and mixing/alternation) for managing wheat blast, we describe a new monitoring tool, enabling the quantitative measurement of pathogen’s inoculum levels and detection of fungicide resistance alleles. Wheat blast airborne spores (aerosol populations) were monitored at Londrina in Paraná State, a major wheat cropping region in Brazil, using an automated high-volume cyclone coupled with a lab-based quantitative real-time PCR (qPCR) assay. The objectives of our study were as follows: (1) to monitor the amount of PoTl airborne conidia during 2019–2021 based on DNA detection, (2) to reveal the prevalence of QoI resistant (QoI-R) cytochrome b alleles in aerosol populations of wheat blast, and (3) to determine the impact of weather on the dynamics of wheat blast aerosol populations and spread of QoI resistant alleles. PoTl inoculum was consistently detected in aerosols during the wheat cropping seasons from 2019 to 2021, but amounts varied significantly between seasons, with highest amounts detected in 2019. High peaks of PoTl DNA were also continuously detected during the off-season in 2020 and 2021. The prevalence of QoI resistant (QoI-R) cytochrome b G143A alleles in aerosol populations was also determined for a subset of 10 PoTl positive DNA samples with frequencies varying between 10 and 91% using a combination of PCR-amplification and SNP detection pyrosequencing. Statistically significant but low correlations were found between the levels of pathogen and the weather variables. In conclusion, for wheat blast, this system provided prior detection of airborne spore levels of the pathogen and of the prevalence of fungicide resistance alleles
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