132 research outputs found

    Respuesta agronómica a largo plazo del cultivo del almendro sometido a dos estrategias de riego deficitario

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    Comunicación presentada al XXXVII Congreso Nacional de Riegos, celebrado en Don Benito del 4 al 6 de Junio de 2019 y organizada por la Asociación Española de Riegos y Drenajes y la Universidad de ExtremaduraEl objetivo del presente trabajo fue evaluar la respuesta agronómica a largo plazo del cultivo del almendro (cv. Guara) sometido a dos estrategias de riego deficitario durante el periodo de llenado de grano, recibiendo cantidades similares de agua, pero con una distribución del estrés diferenciada a lo largo del tiempo; para poder definir la mejor estrategia posible minimizando las perdidas de producción e incrementando el uso eficiente del agua

    Irrigation alternatives for avocado (Persea Americana Mill.) in the Mediterranean Subtropical region in the context of climate change: a review

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    Due to congenital features, avocado (Persea Americana Mill.) trees are substantial water users relative to other fruit trees. The current growing deficiency of water resources, especially in arid and semi-arid avocado-producing areas, has led to the demand for more sustainable water-saving measures. The objective of this review was to analyze the role of deficit irrigation as a strategy to face climate change and water scarcity through achieving efficiency, saving water, and maximizing the benefits that could be achieved at the level of the irrigated agricultural system. Particular attention is devoted to studies performed in the subtropical Mediterranean climate, in which irrigated avocado orchards are common. These studies analyzed irrigation demand, deficit irrigation, and determination of water status through physiological parameters, leading to possible sustainable irrigation programs for avocado in the context of water shortage scenarios. Through these insights, we conclude that under the current climatic circumstances with respect to available water resources, avocado farming requires sustainable resilience strategies to reduce irrigation water consumption without affecting the yield and quality of the fruits. Water stress inevitably affects the physiological processes that determine yield. Therefore, an admissible yield loss is required with smaller fruits and water savings made through deficit irrigation strategies. In addition, modern consumers tend to prefer foods based on sustainability, i.e., there is a high demand for socially responsible and environmentally friendly products

    Thermal Imaging at Plant Level to Assess the Crop-water Status in Almond Trees (cv. Guara) Under Deficit Irrigation Strategies

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    Almond (Prunnus dulcis Mill.) has been traditionally associated to marginal land cultivation and rain-fed agriculture in South Spain. However, in the last years, this crop is being progressively introduced in more productive agricultural areas within the Guadalquivir river basin, where the available water resources are not enough to satisfy the adequate crop-water requirements. Considering this limitation, a more precise irrigation scheduling to maximize the yield is required. Infrared thermal imaging emerges as alternative to other traditional methodologies to assess the crop-water status, especially when deficit irrigation (DI) strategies are being applied. The aim of this study was to define the methodology to assess the almond water status by means of thermal information. The trial was conducted during 2014, during the kernel-filling period, in an almond experimental orchard (SW Spain), with 5-year-old trees, subjected to three irrigation regimes: i) a full-irrigation treatment (C-100), which received 100% of ETC; ii) a regulated deficit irrigation (RDI-50), which received 100% of ETC except during the kernel filling period, when this treatment was irrigated with 50% of ETC; iii) and a low-frequency deficit irrigation treatment (LFDI), which received 100% of ETC except during the kernel filling period, when it was subjected to continuous periods of irrigation-restriction, defined in terms of the threshold values of shaded leaf water potential (Ψleaf). Three daily curves of canopy temperature (TC), stomatal conductance to water vapour (gs) and Ψleaf with measurements at 8:00, 11:00, 14:00, 17:00 and 20:00 were developed. Additionally, Crop Water Stress Index (CWSI), temperature difference between canopy and the surrounding air (ΔTcanopy-air), and the relative index to stomatal conductance (IG) obtained at different scales (canopy and row) were estimated. Significant correlations of infrared thermal information vs. Ψleaf and gs were obtained (p ≤ 0.05 and p ≤ 0.01), in particular, by using the thermal readings taken at 11:30, 14:30 at 17:30 h, especially robust were the relationships obtained between TC and CWSI with Ψleaf at 11:30 h; and between TC and CWSI with gs, and Ψleaf at 14:30 h. Finally, considering the infrared thermal monitoring procedure (readings at tree and row level), similar values of TC were obtained, and therefore, the images taken at row level offered a better information with a higher feasibility in terms of image processing.European Commission. Fondo Europeo de Desarrollo Regional AVA.AVA201601.1

    Fabrication of luminescent nanostructures by electron-beam direct writing of PMMA resist

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    We report on the conversion of non-luminescent conventional poly(methylmethacrylate) (PMMA)-based electron-beam resists into luminescent materials when used as negative-tone resists, that is, when exposed to high electron irradiation doses. Raman spectroscopy reveals the chemical transformation induced by electron irradiation which is responsible for the observed luminescence in the visible (blue) region. The emission intensity from exposed PMMA-based patterns can be controlled by the electron irradiation dose employed to create them

    Quantitative analysis of almond yield response to irrigation regimes in Mediterranean Spain

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    Almond plantations are expanding worldwide, specifically in Spain; the new orchards are often designed under more intensive systems in comparison to the traditional rainfed orchards frequently found in the Mediterranean Sea basin. In these new areas, water is the main limiting factor, and therefore, the present research is aimed at quantitatively analyzing previous findings obtained in irrigation field trials carried out in Spain with mature almond trees. The goal was to derive applied water-production functions and compare sustained and regulated deficit irrigation strategies to provide robust information on the marginal water productivity and the preferred irrigation option to be applied under water scarcity conditions. This quantitative analysis reported a yield increase as water application increased, with the highest potential yield of about 2500 kg/ha achieved with around 1000 mm of irrigation water applied. Under severe water restrictions, similar responses were observed regardless of the deficit irrigation technique employed. In contrast, under moderate water stress, it seems more advantageous to apply a regulated deficit irrigation strategy rather than a sustained deficit strategy. The reported results are useful for deriving more sustainable irrigation protocols and highlight the need to optimize other inputs in addition to water to take full advantage of the irrigation intensification to be carried out in the new almond plantations.Publishe

    Can Sustained Deficit Irrigation Save Water and Meet the Quality Characteristics of Mango?

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    Mango is one of the most cultivated tropical fruits worldwide and one of few drought-tolerant plants. Thus, in this study the effect of a sustained deficit irrigation (SDI) strategy on mango yield and quality was assessed with the aim of reducing irrigation water in mango crop. A randomized block design with four treatments was developed: (i) full irrigation (FI), assuring the crop’s water needs, and three levels of SDI receiving 75%, 50%, and 33% of irrigation water (SDI75, SDI50, and SDI33). Yield, morphology, color, titratable acidity (TA), total soluble solids (TSS), organic acids (OA), sugars, minerals, fiber, antioxidant activity (AA), and total phenolic content (TPC) were analyzed. The yield was reduced in SDI conditions (8%, 11%, and 20% for SDI75, SDI50, and SDI33, respectively), but the irrigation water productivity was higher in all SDI regimes. SDI significantly reduced the mango size, with SDI33 generating the smallest mangoes. Peel color significantly changed after 13 days of ripening, with SDI75 being the least ripe. The TA, AA, and citric acid were higher in SDI75, while the TPC and fiber increased in all SDI levels. Consequently, SDI reduced the mango size but increased the functionality of samples, without a severe detrimental effect on the yield

    Engineering the Controlled Assembly of Filamentous Injectisomes in E. coli K-12 for Protein Translocation into Mammalian Cells.

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    Bacterial pathogens containing type III protein secretion systems (T3SS) assemble large needle-like protein complexes in the bacterial envelope, called injectisomes, for translocation of protein effectors into host cells. The application of these molecular syringes for the injection of proteins into mammalian cells is hindered by their structural and genomic complexity, requiring multiple polypeptides encoded along with effectors in various transcriptional units (TUs) with intricate regulation. In this work, we have rationally designed the controlled expression of the filamentous injectisomes found in enteropathogenic Escherichia coli (EPEC) in the nonpathogenic strain E. coli K-12. All structural components of EPEC injectisomes, encoded in a genomic island called the locus of enterocyte effacement (LEE), were engineered in five TUs (eLEEs) excluding effectors, promoters and transcriptional regulators. These eLEEs were placed under the control of the IPTG-inducible promoter Ptac and integrated into specific chromosomal sites of E. coli K-12 using a marker-less strategy. The resulting strain, named synthetic injector E. coli (SIEC), assembles filamentous injectisomes similar to those in EPEC. SIEC injectisomes form pores in the host plasma membrane and are able to translocate T3-substrate proteins (e.g., translocated intimin receptor, Tir) into the cytoplasm of HeLa cells reproducing the phenotypes of intimate attachment and polymerization of actin-pedestals elicited by EPEC bacteria. Hence, SIEC strain allows the controlled expression of functional filamentous injectisomes for efficient translocation of proteins with T3S-signals into mammalian cells

    Integrando escalas y métodos LTER para comprender la dinámica global de un espacio protegido de montaña: el Parque Nacional de Ordesa y Monte Perdido.

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    Los espacios protegidos, por el hecho de albergar una gran geo-biodiversidad y asegurar una baja intervención humana, constituyen lugares muy adecuados para el seguimiento de organismos y procesos a escala ecológica, así como para la obtención de series temporales largas a escala geológica. En el marco de la red LTER-España, el Parque Nacional de Ordesa y Monte Perdido (PNOMP) y el Instituto Pirenaico de Ecología-CSIC están impulsando estudios para la detección de cambios a distintas escalas mediante variados métodos y aproximaciones. Destacamos aquí los más consolidados, entre los que se encuentran los análisis de registros de sedimentos en lagos, espeleotemas en cuevas, la dinámica de uno de los pocos glaciares activos de la Península ibérica, el análisis físico-químico de aguas corrientes e ibones de alta montaña, el registro del cambio climático actual en árboles longevos, la afección que éste ejerce sobre masas actuales de pinos en el límite superior del bosque y de abetales en zonas húmedas, la matorralización de algunos pastos y los procesos mecanicistas que subyacen, la reorganización de la diversidad florística en pastos tras el abandono paulatino o drástico de la ganadería, la biodiversidad de las comunidades alpinas y la dinámica poblacional de especies amenazadas o indicadoras de hábitats o de motores de cambio global. Los seguimientos ecológicos actuales muestran que tanto el cambio climático como el de usos del suelo están teniendo una considerable trascendencia en la fisionomía y la estructura de algunos de los ambientes más icónicos y frecuentes del parque (deterioro del glaciar, termofilización de la flora en cumbres alpinas, densificación del bosque en su límite superior, pérdida de productividad en algunos pastos supraforestales, etc.). También sugieren una importante variabilidad espacial en los procesos (por ej. en el PNOMP conviven pastos matorralizados y pastos muy estables), y evidencian que los cambios observados no siempre siguen los paradigmas establecidos (por ej., las especies amenazadas mantienen dinámicas poblacionales estables). La integración de resultados parciales proporcionados por cada aproximación relativiza la importancia de las percepciones que cada estudio destaca por separado, y permite medir los cambios actuales en el marco de referencia de los cambios a escala geológica.Predecir la resistencia y resiliencia de los ecosistemas o las poblaciones de seres vivos para enfrentarse a los futuros cambios ambientales es complicado, no sólo por la falta de conocimientos disponibles sino también porque las respuestas que observamos no siempre son tan rápidas o lineales como se espera. La modelización constituye una herramienta cada vez más utilizada, pero requiere de evidencias reales para validar sus pronósticos, por lo que la observación de los procesos que actúan en el PNOMP ha de incluir un esfuerzo continuado de monitorización multiescalar y multidisciplinar de los distintos componentes de la geo, hidro-, crio- y biosfera, sin olvidar el componente humano. Entender la complejidad supone conectar las interacciones que existen entre todos los sistemas y ponderar sus efectos según las escalas de trabajo

    Forest as Stronghold of Local Ecological Practice: Currently Used Wild Food Plants in Polesia, Northern Ukraine

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    Local ecological practice (LEP, e.g., the everyday practice of collecting and using plants, including wild food plants) is shaped by nature (available local resources) and culture (local perceptions and knowledge on their usability), including a multitude of factors, among which language and geographical or cultural separation have been found to play crucial roles in affecting biocultural diversity. Also, proximity to the forest has been shown to increase the use of plants. We conducted ethnobotanical fieldwork within eastern and western regions of Ukrainian Polesia, during which we interviewed 118 people. Through semi-structured interviews, we recorded the distribution of the current uses of 70 wild food taxa. The analysis of use records revealed homogeneous distribution of use despite the geographical distance and different spoken dialects; however, we were able to single out the highly sylvan region of eastern Polesia as the area with highest biocultural diversity for the use of wild food plants. The results suggest that in the context of the overall homogenization of local ecological knowledge, the continued existence of unintended contact with nature through living and working in the forest may be the primary factor maintaining the broader LEP in the sylvan area of eastern Polesia. Місцева екологічна практика (MЕП, що включає повсякденну практику збору та використання дикорослих рослин у їжу) формується природою (місцевими ресурсами) та культурою (місцеві знання про їх використання), що включає безліч чинників, серед яких мова та географічне або культурне відокремлення відіграють вирішальну роль у впливі на біокультурне різноманіття. Також показано, що близькість до лісу збільшує використання рослин. Ми проводили етноботанічні польові роботи у двох областях Українського Полісся, в ході яких ми провели інтерв’ю з 118 людьми. За допомогою напівструктурованих інтерв’ю ми задокументували поточне використання 70 таксонів дикорослих рослин у їжу. Аналіз записів про вживання свідчить про однорідний розподіл використання, незважаючи на географічне розташування та різні розмовні діалекти; однак, ми змогли виділити лісистий регіон Східного Полісся як територію з найвищим біокультурним різноманіттям використання дикорослих рослин уїжу. Результати свідчать, що в контексті загальної гомогенізації місцевих екологічних знань, продовження існування контакту з природою живучи та працюючи в лісі може бути основним чинником, який підтримує ширшу MЕПу в лісовій зоні Східного Полісся

    A formative study exploring perceptions of physical activity and physical activity monitoring among children and young people with cystic fibrosis and health care professionals

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    Background: Physical activity (PA) is associated with reduced hospitalisations and maintenance of lung function in patients with Cystic Fibrosis (CF). PA is therefore recommended as part of standard care. Despite this, there is no consensus for monitoring of PA and little is known about perceptions of PA monitoring among children and young people with CF. Therefore, the research aimed to explore patients’ perceptions of PA and the acceptability of using PA monitoring devices with children and young people with CF. Methods: An action research approach was utilised, whereby findings from earlier research phases informed subsequent phases. Four phases were utilised, including patient interviews, PA monitoring, follow-up patient interviews and health care professional (HCP) interviews. Subsequently, an expert panel discussed the study to develop recommendations for practice and future research. Results: Findings suggest that experiences of PA in children and young people with CF are largely comparable to their non-CF peers, with individuals engaging in a variety of activities. CF was not perceived as a barrier per se, although participants acknowledged that they could be limited by their symptoms. Maintenance of health emerged as a key facilitator, in some cases PA offered patients the opportunity to ‘normalise’ their condition. Participants reported enjoying wearing the monitoring devices and had good compliance. Wrist-worn devices and devices providing feedback were preferred. HCPs recognised the potential benefits of the devices in clinical practice. Recommendations based on these findings are that interventions to promote PA in children and young people with CF should be individualised and involve families to promote PA as part of an active lifestyle. Patients should receive support alongside the PA data obtained from monitoring devices. Conclusions: PA monitoring devices appear to be an acceptable method for objective assessment of PA among children and young people with CF and their clinicians. Wrist-worn devices, which are unobtrusive and can display feedback, were perceived as most acceptable. By understanding the factors impacting PA, CF health professionals will be better placed to support patients and improve health outcomes
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