754 research outputs found

    Herbivoria de Tetranychus urticae Koch (Acari: tetranychidae) induz defesa direta em morangueiro?

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    Plantas de morangueiro Fragaria x ananassa podem apresentar mecanismos de defesa direta e indireta contra herbívoros. Tais defesas podem alterar o comportamento e o desenvolvimento dos ácaros fitófagos e seus inimigos naturais, reduzindo a taxa de herbivoria. Testou-se o efeito da préinfestação de plantas de morangueiro por Tetranychus urticae Koch sobre o seu desenvolvimento e reprodução. Plantas de morangueiro cultivar IAC Campinas foram divididas em dois grupos: plantas limpas e plantas pré-infestadas por T. urticae. A infestação prévia de plantas de morangueiro por T. urticae não alterou a duração das fases imaturas, a fecundidade e a sobrevivência das fêmeas do ácaro. Tais resultados podem estar associados à inexistência ou baixo nível de resistência induzida da cultivar IAC Campinas, ou ainda, ao fato de a pré-infestação ter sido insuficiente para induzir defesa. Assim, a resistência relatada na cultivar IAC Campinas a T. urticae pode estar relacionada às defesas indiretas

    Os ácaros são pragas do milho no Brasil?

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    Natural control of Helicoverpa armigera (Lepidoptera: Noctuidae) pupae in organic and conventional maize crops.

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    The natural biological control of soil pests is poorly studied. Notably, the control of Helicoverpa armigera in the pupae stage is unknown. To increase knowledge about the control of this pest in organic and conventional maize crop, tests were conducted to verify if the duration of pupae availability in days, the type of crop treatment (organic and conventional), the stage of crop development, and the depth of the soil significantly affect predation by natural enemies. The pupae availability time (days) in the soil did not affect their removal by natural enemies. However, in the fallow stage, on the surface and in the reproductive phase, the predation was higher. In organic maize, predation was 15% higher when compared to conventional maize. The rupture of the soil and the possible losses associated with beneficial fauna were the main factors responsible for higher predation during fallow, so conservationist practices usually used in organic treatment are the main reason for higher predation in this type of crop. There is a significant decrease in the control of H. armigera pests by natural enemies when maize is grown using conventional practices, what reinforces the importance of the conservation techniques used in maize crop

    Effects of the SGLT2 inhibitor dapagliflozin on cardiac function evaluated by impedance cardiography in patients with type 2 diabetes. Secondary analysis of a randomized placebo-controlled trial

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    Cardiovascular outcome trials have documented a strong benefit of sodium glucose cotransporter-2 inhibitors (SGLT2i) on the risk of hospitalization for heart failure (HF) in patients with type 2 diabetes (T2D) with or without established cardiovascular disease or prior history of HF. The mechanisms, however, are not entirely clear. We aimed to evaluate whether treatment with SGLT2i affected cardiac function using impedance cardiography (ICG) in a randomized placebo-controlled trial

    Comparative effectiveness of dapagliflozin vs DPP-4 inhibitors on a composite endpoint of HbA1c, body weight and blood pressure reduction in the real world

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    Background: Treatment of type 2 diabetes (T2D) should aim at preventing or delaying complications through the control of glycaemia and cardiovascular risk factors. We herein compared the SGLT-2 inhibitor dapagliflozin vs DPP-4 inhibitors (DPP-4i) on a composite endpoint of glycaemic and extraglycaemic effectiveness. Methods: This was a multicentre, retrospective real-world study conducted at 56 outpatient clinics in Italy. We collected data on patients newly started on dapagliflozin or DPP-4i in 2015-2017. The primary endpoint was the proportion of patients attaining a simultaneous reduction of HbA1c ≥0.5%, body weight ≥2 kg, systolic blood pressure (SBP) ≥2 mmHg. Confounding by indication was addressed by propensity score matching (PSM) or multivariable adjustment (MVA). Results: Patients initiating dapagliflozin (n = 2091) or DPP-4i (n = 2144) differed for most clinical characteristics. After PSM, two well-balanced groups of 1149 patients each were compared. The primary endpoint was reached in a greater proportion of patients who received dapagliflozin (17.6%) compared to DPP-4i (11.7%), with a relative risk of 1.50 (1.21-1.86; P <.001). Similar results were obtained in the as-treated and intention-to-treat datasets or using MVA in place of PSM. The beneficial effect of dapagliflozin was mainly due to its greater effectiveness on body weight and, to a lesser extent, on SBP. The change in HbA1c did not differ between groups. Conclusions: T2D patients initiating the SGLT2i dapagliflozin had a greater probability of attaining a composite endpoint of clinically relevant reductions in HbA1c, body weight and SBP, compared to similar patients initiating a DPP-4i in the same period and healthcare setting
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