231 research outputs found

    Frequencias de alternancia no molhamento parcial do sistema radicular do limoeiro no Norte de Minas Gerais.

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    No Brasil, 61% da água é consumida pela agricultura irrigada (Santos & Anjos, 2001). Uma dessas evidencias ocorre nos perímetros irrigados onde as irrigações são geralmente realizadas em excesso. Além do maior gasto de água, regas excessivas acarretam prejuízos à produção, maior incidência de doenças e impacto ambiental (Lopes et al., 2006). Em plantas cítricas, tem-se demonstrado que a produção e qualidade dos frutos são muito afetadas pela qualidade da irrigação nos períodos de floração e ?pegamento? de frutos (Fase I) e de crescimento rápido do fruto (Fase II) (Domingo et al., 1996). O molhamento parcial do sistema radicular (MPSR) tem sido uma tecbica usada recomendada para diferentes culturas com objetivo de racionalização do uso de água sem redução significativa da produtividade potencial da cultura. Consiste na alternância da irrigação em dois lados de uma planta, a freqüência definida, sendo que as mais usadas tem sido 7, 14 e 21 dias (Kang & Zang, 2004). O secamento do solo de um lado acarreta redução da transpiração da planta, sem que a mesma manifeste sintomas de estresse acentuado. Essa tecnologia tem sido avaliada principalmente na Austrália e África do Sul com aumento de até 80% na eficiência de uso de água. Este trabalho objetiva definir a freqüência de alternância do lado irrigado da planta e a percentagem de redução da lamina aplicada na técnica do molhamento parcial do sistema radicular da lima ácida Tahiti nas condições do Norte de Minas em solo de textura arenosa.pdf 165

    Área e índice de área foliar de bananeiras prata-anã e BRS platina submetidas à adubação orgânica.

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    A 'Prata-Anã é a principal variedade cultivada nos Perímetros Públicos de Irrigação do 7 Sudoeste da Bahia e do Norte de Minas Gerais, mas apesar da boa aceitação comercial é susceptível 8 às sigatokas e ao mal-do-Panamá. A ?BRS Platina? (AAAB), um híbrido recentemente 9 recomendado (BORGES et al., 2014), é indicado como alternativa à 'Prata-Anã', em ambientes onde 10 o mal-do-Panamá é fator limitante ao cultivo, além de frutos com melhor classificação comercial

    Multimethod Assessment of Design, Metallurgical, and Mechanical Characteristics of Original and Counterfeit ProGlider Instruments

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    Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.A multimethod study was conducted to assess the differences between original (PG-OR) and counterfeit (PG-CF) ProGlider instruments regarding design, metallurgical features, and mechanical performance. Seventy PG-OR and PG-CF instruments (n = 35 per group) were evaluated regarding the number of spirals, helical angles, and measuring line position by stereomicroscopy, while blade symmetry, cross-section geometry, tip design, and surface were assessed by scanning electron microscopy. Energy-dispersive X-ray spectroscopy and differential scanning calorimetry were used to identify element ratio and phase transformation temperatures, while cyclic fatigue, torsional, and bending testing were employed to assess their mechanical performance. An unpaired t-test and nonparametric Mann–Whitney U test were used to compare instruments at a significance level of 5%. Similarities were observed in the number of spirals, helical angles, blade symmetry, cross-sectional geometries, and nickel–titanium ratios. Measuring lines were more reliable in the original instrument, while differences were noted in the geometry of the tips (sharper tip for the original and rounded for the counterfeit) and surface finishing with PG-CF presenting more surface irregularities. PG-OR showed significantly more time to fracture (118 s), a higher angle of rotation (440°), and a lower maximum bending load (146.3 gf) (p 0.05). Although the tested instruments had a similar design, the original ProGlider showed superior mechanical behavior. The results of counterfeit ProGlider instruments were unreliable and can be considered unsafe for glide path procedures.publishersversionpublishe

    Efficiency of microsatellite markers in assisted selection for resistance to soybean cyst nematode (race 3).

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    Four microsatellite sequences were tested in soybean DNA from cultivars and segregating genotypes. Three of them were close to the resistance locus rhg 1 on molecular linkage group G (Satt 309, Sat_168, Sat_163) and one was close to Rhg4 locus on group A2 (Sat_162). Progenies previously classified as cyst nematode (SNC) resistant and others with unknown reaction were tested, using the resistant cultivars Liderança, and Renascença and the susceptibles 'Cristalina' and 'OCEPAR-4' as control. The best primer for resistance to SCN was Sat_162. Twenty segregant progenies tested with Sat_162 presented a 150 bp band for homozygous resistant genotypes and 200 bp for susceptible ones, and both for the heterozigous genotypes. Previous studies have shown that this microsatellite marker is efficient to select genotypes carrying Peking-derivative resistance. 'Peking' takes part in the in the genealogy of all segregant progenies evaluated in this study. Thus, the obtained results showed that Sat_162 distinguished resistant and susceptible soybean genotypes to SCN, race 3

    Design, Metallurgical Features, and Mechanical Behaviour of NiTi Endodontic Instruments from Five Different Heat-Treated Rotary Systems

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    UIDB/50025/2020-2023The current study aimed to compare the F1 endodontic instruments from five different heat-treated rotary systems regarding their design, metallurgical properties, and mechanical performance. Five F1 root canal shaping instruments (ProTaper Gold [PTG], Premium Taper Gold, Go-Taper Flex, EdgeTaper Platinum, and Super Files Blue)—plus, a conventional ProTaper Universal (PTU)—which were evaluated regarding their design, nickel/titanium ratio, phase transformation temperatures, microhardness, cyclic fatigue, and torsional and bending strengths. Mood's median test was used for the statistical comparison with a significance set at 5%. The instruments were similar regarding the nickel/titanium ratio and overall design. Go-Taper Flex had the closest transformation temperatures to PTG. PTU and Go-Taper Flex had the highest microhardness (408.3 and 410.5 HVN). The time to fracture of Super Files Blue was three and seven times higher than PTG and PTU, respectively. No difference was observed in the maximum torque to fracture among PTG (1.30 N·cm) and the other systems, except for the Premium Taper Gold (1.05 N·cm) and Go-Taper Flex (1.10 N·cm). Significantly lower bending loads than PTG (269.2 gf) were observed for the EdgeTaper Platinum (158.3 gf) and Premium Taper Gold (103.5 gf) instruments. Super Files Blue outperformed PTG in the cyclic fatigue test, while EdgeTaper Platinum and Premium Taper Gold were more flexible. Premium Taper Gold and Go-Taper Flex showed lower torsional strength.publishersversionpublishe

    Recommendations for Urine and Urinary Bladder Collection in Chemical Carcinogenesis Assays with Rodents

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    This review describes the technical procedures to collect and process urine and urinary bladder samples, during and at the end of urinary bladder carcinogenesis assays with small rodents. The applications, advantages and disadvantages of each method are also mentioned and discussed
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