997 research outputs found
Biological control of banana black Sigatoka disease with Trichoderma.
A Sigatoka-negra causada por Mycosphaerella fijiensis é a doença mais destrutiva da bananeira em termos mundiais. O patógeno está em uma fase invasiva no Brasil e já se encontra distribuído na maior parte dos Estados do país. O potencial de 29 isolados de Trichoderma spp. para o controle da Sigatoka-negra foi estudado sob condições de campo. Quatro isolados foram capazes de reduzir significativamente a severidade da doença e foram selecionados para um segundo experimento de campo. O isolado 2.047 apresentou os melhores resultados e foi utilizado em testes de sensibilidade a fungicidas e produção massal. Esse isolado foi identificado como Trichoderma atroviride por meio do sequenciamento de fragmentos da regiões ITS do rDNA e tef-1? da RNA polymerase. Trichoderma atroviride foi tão efetivo no controle da Sigatoka-negra quanto o fungicida Azoxystrobin, que é recomendado para o controle da doença. O agente de controle biológico tem potencial para o controle da Sigatoka-negra e pode ser produzido em massa em arroz autoclavado para aplicações no campo
Design, Fabrication and Characterization
Funding Information: This work was financed by national funds from FCT, Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication, i3N, and also under project dPCR4FreeDNA of the same research unit, PTDC/BTM-SAL/31201/2017. Furthermore, the work received funding from FCT in the scope of projects UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences, UCIBIO, and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy, i4HB. B. J. Coelho acknowledges FCT for the attribution of grant SFRH/BD/132904/2017 and grant COVID/BD/152453/2022. Publisher Copyright: © 2023 by the authors.Microfluidic-based platforms have become a hallmark for chemical and biological assays, empowering micro- and nano-reaction vessels. The fusion of microfluidic technologies (digital microfluidics, continuous-flow microfluidics, and droplet microfluidics, just to name a few) presents great potential for overcoming the inherent limitations of each approach, while also elevating their respective strengths. This work exploits the combination of digital microfluidics (DMF) and droplet microfluidics (DrMF) on a single substrate, where DMF enables droplet mixing and further acts as a controlled liquid supplier for a high-throughput nano-liter droplet generator. Droplet generation is performed at a flow-focusing region, operating on dual pressure: negative pressure applied to the aqueous phase and positive pressure applied to the oil phase. We evaluate the droplets produced with our hybrid DMF–DrMF devices in terms of droplet volume, speed, and production frequency and further compare them with standalone DrMF devices. Both types of devices enable customizable droplet production (various volumes and circulation speeds), yet hybrid DMF–DrMF devices yield more controlled droplet production while achieving throughputs that are similar to standalone DrMF devices. These hybrid devices enable the production of up to four droplets per second, which reach a maximum circulation speed close to 1540 µm/s and volumes as low as 0.5 nL.publishersversionpublishe
Fertirrigação.
A fertirrigação, técnica de aplicar fertilizantes via água de irrigação, difere significativamente da aplicação via solo, em especial por acelerar o ciclo dos nutrientes utilizados. A disponibilidade de fertilizantes solúveis no mercado, o custo de mão de obra rural na adubação convencional, o constante incremento de área irrigada no Brasil, sob irrigação pressurizada, tudo isso tem incentivado os produtores a adotarem a fertirrigação, uma vez que os custos de implantação, comparados aos custos totais, viabilizam o seu uso. O conhecimento da dinâmica de íons no solo, principalmente do nitrogênio (N) e do potássio (K), tem permitido estabelecer critérios de aplicação desses nutrientes ao solo pela fertirrigação. O conhecimento da necessidade de nutrientes pelas culturas, da marcha de absorção desses nutrientes durante o ciclo, da frequência mais adequada de aplicação desses nutrientes permite determinar a quantidade de fertlizantes e a fase do ciclo em que esses devem ser aplicados. Além disso, é preciso conhecer também o volume de água necessário para compor a solução a ser injetada no sistema de irrigação. A fertirrigação necessita, entretanto, de acompanhamento e avaliação contínua, a fim de evitar impactos negativos ao solo pelo uso indevido da técnica. Isso pode ser feito por meio de acompanhamento da condutividade elétrica da solução ou do extrato de saturação do solo
Open-source tool for real-time and automated analysis of droplet-based microfluidic
Publisher Copyright:
© 2023 The Royal Society of Chemistry.Droplet-based microfluidic technology is a powerful tool for generating large numbers of monodispersed nanoliter-sized droplets for ultra-high throughput screening of molecules or single cells. Yet further progress in the development of methods for the real-time detection and measurement of passing droplets is needed for achieving fully automated systems and ultimately scalability. Existing droplet monitoring technologies are either difficult to implement by non-experts or require complex experimentation setups. Moreover, commercially available monitoring equipment is expensive and therefore limited to a few laboratories worldwide. In this work, we validated for the first time an easy-to-use, open-source Bonsai visual programming language to accurately measure in real-time droplets generated in a microfluidic device. With this method, droplets are found and characterized from bright-field images with high processing speed. We used off-the-shelf components to achieve an optical system that allows sensitive image-based, label-free, and cost-effective monitoring. As a test of its use we present the results, in terms of droplet radius, circulation speed and production frequency, of our method and compared its performance with that of the widely-used ImageJ software. Moreover, we show that similar results are obtained regardless of the degree of expertise. Finally, our goal is to provide a robust, simple to integrate, and user-friendly tool for monitoring droplets, capable of helping researchers to get started in the laboratory immediately, even without programming experience, enabling analysis and reporting of droplet data in real-time and closed-loop experiments.publishersversionepub_ahead_of_prin
Relationship between feed efficiency indexes and performance, body measurements, digestibility, energy partitioning, and nitrogen partitioning in pre-weaning dairy heifers.
Abstract The objectives of this study were: 1) to classify animals into groups of high and low feed efficiency using two feed efficiency indexes (Residual feed intake (RFI) and residual feed intake and body weight gain (RIG)), and 2) to evaluate if pre-weaning heifer calves divergent for feed efficiency indexes exhibit differences in performance, body measurements, digestibility, energy partitioning, and nitrogen partitioning. A total of 32 Gyr heifer calves were enrolled in a 63-d trial and classified into two feed efficiency (FE) groups based on RFI and RIG (mean ± 0.5 SD). The groups were classified as high efficiency (HE) RFI (HE RFI, n = 9; HE RIG, n = 10), and low efficiency (LE) RFI (LE RFI, n = 10; LE RIG, n = 11). The remaining animals were classified as intermediate (n = 13 (RFI) and n = 11 (RIG)). HE and LE calves had RFI values of?0.052 and 0.049 kg/d (P < 0.05), respectively. The HE RFI group consumed 8.9% less solid diet than the LE RFI group. HE RFI animals exhibited an increased digestibility of crude protein and ether extract and tended to have greater total dry and organic matter digestibility. LE RFI animals had greater gross energy and nitrogen intake, though greater fecal losses resulted in a tendency to reduce energy and nitrogen use efficiency. HE and LE calves had RIG values of 0.080 and -0.077kg/d (P ? 0.01), respectively. HE RIG animals exhibited greater average daily gain (9.4%), body weight (BW), and heart girth, though HE RIG group exhibited narrower hip width. HE RIG animals tended to have greater ether extract digestibility but greater methane losses (% of gross energy). HE RFI in pre-weaning heifers seems to be related to differences in digestibility. Divergent animals for RIG during the assessed phase appear to differ in body measurements, which may be related to differences in the composition of the gain
Nitrate concentration in the soil solution as affected by irrigation water concentration in fertirrigation.
The use of fertirrigation provides larger fertilizer application efficiency, reduction on labor and increases in the benefit-cost relationship to farmers. The inadequate use of fertilizer in fertirrigation by application of concentrated injection solutions may raise salt concentration in the soil solution increasing osmotic tension, reducing total soil potential, besides affecting ionic equilibrium in the soil solution. The work had as objective to evaluate three concentrations of urea and calcium nitrate in irrigation water on nitrate concentration in soil solution at two soil depths, considering banana crop grown in Yellow Latossol of coastal tableland. Treatments regarded about using of three calcium nitrate and urea concentrations (1.0; 2.5 and 4.0 g/l) in the irrigation water that was applied in the field by a drip irrigation system during the first cycle of banana crop. Samples of soil solution were collected every 15 days in each plot by water samplers that were installed at 0.30 m from the plant at depths of 0.20 and 0.40 m between two emitters. Nitrate concentration in soil solution increased with the increase of nitrogen source concentration in irrigation water. Mean nitrate concentration of soil solution for 4 gL-¹ concentration of irrigation water was the largest one of both sources and soil depths.PAP1004.pdf
Soil salinity under three calcium nitrate concentrations of irrigation water for two trickle irrigation systems.
Fertilizers are salts that may increase irrigation water salinity, therefore, fertirrigation management should consider aspects like the injection solution. The electrical conductivity of soil solution (ECs) or the soil saturation extract (ECs) may be used to quantify the amount of salts in soil. The objective of this work was to evaluate the effect of calcium nitrate concentration of the irrigation water on the soil electrical conductivity along the first cycle of banana crop. Treatments consisted of using three calcium nitrate concentrations of the solution (1.0; 2.5 and 4.0 g L-¹) to be injected into a drip and a microsprinkler irrigation system during the first cycle of Terra banana crop. There was no significant difference among soil extract saturation means for the two irrigation systems. The absolute values of the electrical conductivities were larger in the wetted volume under drip irrigation system. There was difference among electrical conductivities related to the concentrations of calcium nitrate of the irrigation water. The 4 g L-¹ concentration means were larger than the ones of other concentrations in most of the cases. The use of 4 g L-¹ concentration resulted electrical conductivities of soil solution and of soil extract saturation larger than 1.0 dS m-¹ for at least 80% and 20% of measurements along of cycle, respectively.PAP0828
Relações entre transpiração máxima, evapotranspiração de referência e área foliar em quatro variedades de mangueira
Morphological analysis and description of the ovaries of female silky sharks, Carcharhinus falciformis (Müller & Henle, 1839)
This work aims to study the female reproductive tract of silky sharks, Carcharhinus falciformis, captured in the South and
Equatorial Atlantic Ocean. Samples were collected between January 2008 and March 2010 through oceanic commercial vessels
that targeted tuna and swordfish, with a total of 17 females collected. The methodologies followed for analyzing the ovaries
of those females included both macroscopic and histological analysis. Macroscopically, it was possible to determine that the
ovaries on these sharks is suspended by mesenteries in the anterior section of the body cavity, heavily irrigated by blood
vessels, and contains a wide range of oocytes. Ovaries were found in three distinct maturational stages: Stage I (Immature),
Stage II (Maturing) and Stage III (Mature). Immature ovaries were small, with widths ranging from 1.0 to 3.1 cm, and had a
gelatinous or granulose internal structure; maturing ovaries were slightly larger, ranging in width between 5.2 and 6.0 cm;
mature ovaries ranged in width between 6.5 and 7.8 cm, and had a more rounded shape and the presence of large and well
developed oocytes. Under microscopic examination, it was observed that the ovaries were covered with simple epithelial
tissue during the early development stages and a simple cubic epithelium in the final stages of maturation. During the initial
maturation stages the epigonal organ was not differentiated from the ovary. In mature specimens, the ovary showed a simple
cubic epithelium and just below this epithelium there was a layer of dense connective tissue and muscle with the presence of
vitellogenic oocytes and fat cells. A thin yolk membrane enclosing the oocytes was also evident. Finally, it was possible to
distinguish a zona pellucida, separating the oocytes from the follicle wall and a basal lamina between the granular layers and
the teak layer.info:eu-repo/semantics/publishedVersio
- …