24 research outputs found

    Root temperature and energy consumption at different cable depths in electrically heated substrates

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    A finite element method-based model of a substrate heated by an electric heating cable buried in a thermal isolated container was experimentally validated with root mean square error values of root zone temperature ranging 0.25 to 0.62 ºC. The two-dimensional transient model allowed variations in the physical properties of the substrate with temperature, water content and depth. The operation of nine configurations of a heating cable buried in sand at different depths (50 to 450 mm, at 50 mm intervals) at 200 mm spacing was simulated and assessed. The validated model was used to perform 24-h simulations applying boundary conditions, and substrate moisture content was experimentally obtained at a mean substrate surface temperature of 13.98 ºC. Such simulations reproduced the operation of the heating system by setting a reference temperature of 20 ºC at the control point in the root zone. Burying the heating cable in the surface layers of the substrate caused large temperature gradients and high heat losses through the substrate surface. Accordingly, average temperature in the root zone increased with heating cable depth, up to the 200 mm depth. For greater depths, temperature in the root zone was constant. The ON/OFF control was most effective with the heating cable buried in the root zone and at control point temperatures of 20 ± 1 ºC. Burying the heating cable in the surface layers required higher energy consumption, up to 28 % at 50 mm. The most efficient heating cable depth was 350 mm, with a daily energy consumption of 6750 kJ m-2

    Patients' experience of shoulder disorders

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    Objectives: To describe the experiences (including symptoms and perceived impacts on daily living) of people with a shoulder disorder. Methods: Systematic review of qualitative studies. We searched for eligible qualitative studies indexed in Ovid MEDLINE, Ovid Embase, CINAHL (EBSCO), SportDiscus (EBSCO) and Ovid PsycINFO up until November 2017. Two authors independently screened studies for inclusion, appraised their methodological quality using the Critical Appraisal Skills Programme checklist, used thematic synthesis methods to generate themes describing the experiences reported by participants and assessed the confidence in the findings using the Grading of Recommendations Assessment, Development and Evaluation Confidence in Evidence fro

    Pawiloma rubra sp.n. (Homoptera, Cicadellidae, Cicadellinae) from Belize

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    Descrição da fêmea de Onega bracteata Young (Homoptera, Cicadellidae, Cicadellinae)

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    <abstract language="eng">The female of Onega bracteata Young, 1977 is described by once first. The specimen was colleting in Peru

    Biphasic haustorial differentiation of coffee rust (Hemileia vastatrix race II) associated with defence responses in resistant and susceptible coffee cultivars

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    The objective of this study was to assess whether defence responses in coffee (Coffea arabica) were linked to a specific developmental stage of the rust fungus Hemileia vastatrix. Histological observations in compatible and incompatible highyielding Brazilian coffee cultivars showed that the fungus produced 'pioneer' haustoria in adjacent and subsidiary stomatal cells soon after entering the stomata, followed by later developed 'secondary haustoria' which invade mesophyll cells. In the incompatible interaction between Race II and cv. Tupi, a strong and transient H2O2 generation at infection sites was detected at 39 h post inoculation (hpi) during secondary haustoria formation. In addition, clear-cut differences in defence gene expression between compatible and incompatible interactions were only observed during the secondary haustoria formation. Transcripts of the pathogenesis-related (PR) genes CaPR1b and CaPR10 accumulated to maximal levels at 39 hpi (38- and 86-fold, respectively) in the incompatible interaction, but stayed at low levels in the compatible interaction. In contrast, the CaWRKY1 gene and the CaRLK gene were only induced in the susceptible cultivar. These results indicated that the specific resistance of cv. Tupi was expressed after differentiation of the H. vastatrix secondary haustoria. Analysis showed no evidence of specific recognition of coffee rust at the pioneer haustoria stage, suggesting that haustoria components are not recognized by, or not secreted into, the subsidiary and adjacent cells of the stomata. Additionally, the present study provides new insights into the colonization process of the coffee rust fungus. (Résumé d'auteur
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