522 research outputs found

    Water use and soil water balance of Mediterranean tree crops assessed with the SIMDualKc model in orchards of southern Portugal

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    Orchards consist of complex agricultural systems, with a variety of characteristics (planting density, tree height, training system, canopy cover, irrigation method, interrow management) influencing crop evapotranspiration (ETc). Thus, irrigation water management requires finding crop coefficients (Kc) that represent the characteristics of local orchards, evidencing the need for site specific data. The main objective of this study was to derive the Kc of almond, olive, citrus, and pomegranate orchards in Alentejo, southern Portugal, wherein they became dominant over the last decade. Monitoring was carried out in nine orchards, which management decisions were performed by the farmers. The ETc was estimated from the soil water balance computed for each orchard using the FAO56 dual-Kc approach with the SIMDualKc model. The model successfully simulated the soil water contents measured in the various fields along two growing seasons, with root mean square error values lower than 0.005 m3 m− 3 and modeling efficiencies from 0.363 to 0.782. The estimated basal crop coefficients (Kcb) for the initial, mid- and end-seasons were respectively 0.22, 0.58, and 0.50 for almond; 0.32–0.33, 0.35–0.36, and 0.33–0.34 for olive; 0.40, 0.40–41, and 0.40–0.41 for citrus; and 0.24, 0.60, and 0.52 for pomegranate. Small variations in olive and citrus Kcb values were found to be related to differences in the fraction of the ground covered by trees’ canopies and tree height. The single Kc values, which included the component relative to soil evaporation, were also estimated. Furthermore, evaluation of the soil water balance in the nine case studies showed salinity effects in one almond orchard, mild irrigation water deficits in olive systems, and large nonconsumptive water use in citrus and pomegranate orchards. These results evidence the need for better management of orchards irrigation water in the region, and the current study provides for reliable information on the Kc of tree crops to support improving the management of local orchard systems and the preservation of soil and water resources. Aimed at these resources and the sustainability of their use, simulated alternative irrigation schedules were performed, which identified possible water savings of 20 mm in case of olives, up to 855 mm for citrus.info:eu-repo/semantics/publishedVersio

    Water use, soil water balance and soil salinization risks of Mediterranean tree orchards in southern Portugal under current climate variability: Issues for salinity control and irrigation management

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    Secondary salinization has long been reported in the Roxo irrigation district (RID), southern Portugal, due to the use of saline-prone irrigation water and the existence of poorly structured soils. This study assessed the soil water and salt budgets in nine commercial orchards located in the RID using the multiple ion chemistry module available in the HYDRUS-1D model during the 2019 and 2020 growing seasons. The studied crops were almond, olive, citrus (orange, mandarin, and clementine), and pomegranate. The model successfully simulated soil water contents measured in the different fields but there was a clear underestimation of the electrical conductivity of the soil saturation paste extract (ECe) in some locations, while simulations of the sodium adsorption ratio (SAR) were generally acceptable. Modeling errors were mostly associated with missing information on fertigation events rather than related to the effects of irrigation water quality. The water and salt balances were also computed for the 1979–2020 period. Considering the probability of non-exceedance of salt accumulation during this period, the risk of salinity build-up was high to very high for the very dry years in most fields, except in the citrus sites. The factors influencing the salt accumulation were the irrigation strategy, the seasonal irrigation and rainfall depths, the duration of the crop growth period, the rainfall distribution in the late and non-growing stages, the soil drainage conditions, and the irrigation water quality. For the current climate conditions and irrigation water quality, the risk of soil salinity levels affecting crop development and yields was found to be minor. This means that, despite salts tended to accumulate in the rootzone over a season, under current conditions the salinity stress did not reach harmful levels for plants. Only in two of the study sites, there was a need to promote salt leaching. Hence, this study shows that soil salinization risks in the study area are low but, for given locations during drier seasons, there is a need for tailored irrigation solutions aimed at the conservation of soil and water resources.info:eu-repo/semantics/publishedVersio

    SDR-Based High-Definition Video Transmission for Biomedical Engineering

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    Background: Software-Defined Radio (SDR) frameworks from cellular telephone base stations, e.g., Multiservice Distributed Access System (MDAS) and small cells, employ extensively integrated RF agile transceivers. The Internet of Medical Things (IoMT) is the collection of medical devices and applications that connect to healthcare IT systems through online computer networks. Medical devices equipped with Wi-Fi allow M2M communication, which is the backbone of IoMT and associated devices linked to cloud platforms containing stored data to be analyzed. Examples of IoMT include remote patient monitoring of people with chronic or long-term conditions, tracking patient medication orders and the location of patients admitted to hospitals, and patients' wearables to send info to caregivers. Infusion pumps connected to dashboards and hospital beds rigged with sensors measuring patients' vital signs are medical devices that can be converted to or deployed as IoMT technology. Methods: This work proposes an SDR architecture to allow wireless High-Definition (HD) video broadcast for biomedical applications. This text examines a Wideband Wireless Video (WWV) signal chain implementation using the transceivers, the data transmitted volume, the matching occupied RF bandwidth, the communication distance, the transmitter’s power, and the implementation of the PHY layer as Orthogonal Frequency Division Multiplexing (OFDM) with test results to evade RF interference. Results: As the IoMT grows, the amount of possible IoMT uses increases. Many mobile devices employ Near Field Communication (NFC) Radio Frequency Identification (RFID) tags allowing them to share data with IT systems. RFID tags in medical equipment and supplies allow hospital staff can remain aware of the quantities they have in stock. The practice of using IoMT devices to observe patients in their homes remotely is also known as telemedicine. This kind of treatment spares patients from traveling to healthcare facilities whenever they have a medical question or change in their condition. Conclusion: An SDR-based HD biomedical video transmission is proposed, with its benefits and disadvantages for biomedical WWV are discussed. The security of IoMT sensitive data is a developing concern for healthcare providers

    Colloidal nanomaterials for water quality improvement and monitoring

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    Water is the most important resource for all kind forms of live. It is a vital resource distributed unequally across different regions of the globe, with populations already living with water scarcity, a situation that is spreading due to the impact of climate change. The reversal of this tendency and the mitigation of its disastrous consequences is a global challenge posed to Humanity, with the scientific community assuming a major obligation for providing solutions based on scientific knowledge. This article reviews literature concerning the development of nanomaterials for water purification technologies, including collaborative scientific research carried out in our laboratory (nanoLAB@UA) framed by the general activities carried out at the CICECO-Aveiro Institute of Materials. Our research carried out in this specific context has been mainly focused on the synthesis and surface chemical modification of nanomaterials, typically of a colloidal nature, as well as on the evaluation of the relevant properties that arise from the envisaged applications of the materials. As such, the research reviewed here has been guided along three thematic lines: 1) magnetic nanosorbents for water treatment technologies, namely by using biocomposites and graphite-like nanoplatelets; 2) nanocomposites for photocatalysis (e.g., TiO2/Fe3O4 and POM supported graphene oxide photocatalysts; photoactive membranes) and 3) nanostructured substrates for contaminant detection using surface enhanced Raman scattering (SERS), namely polymers loaded with Ag/Au colloids and magneto-plasmonic nanostructures. This research is motivated by the firm believe that these nanomaterials have potential for contributing to the solution of environmental problems and, conversely, will not be part of the problem. Therefore, assessment of the impact of nanoengineered materials on eco-systems is important and research in this area has also been developed by collaborative projects involving experts in nanotoxicity. The above topics are reviewed here by presenting a brief conceptual framework together with illustrative case studies, in some cases with original research results, mainly focusing on the chemistry of the nanomaterials investigated for target applications. Finally, near-future developments in this research area are put in perspective, forecasting realistic solutions for the application of colloidal nanoparticles in water cleaning technologies.publishe

    Xylella fastidiosa comparative genomic database is an information resource to explore the annotation, genomic features, and biology of different strains

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    The Xylella fastidiosa comparative genomic database is a scientific resource with the aim to provide a user-friendly interface for accessing high-quality manually curated genomic annotation and comparative sequence analysis, as well as for identifying and mapping prophage-like elements, a marked feature of Xylella genomes. Here we describe a database and tools for exploring the biology of this important plant pathogen. The hallmarks of this database are the high quality genomic annotation, the functional and comparative genomic analysis and the identification and mapping of prophage-like elements. It is available from web site http://www.xylella.lncc.br

    Insights into milk-clotting activity of latex peptidases from <i>Calotropis procera</i> and <i>Cryptostegia grandiflora</i>

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    Latex fractions from Calotropis procera, Cryptostegia grandiflora, Plumeria rubra, and Himatanthus drasticus were assayed in order to prospect for new plant peptidases with milk-clotting activities, for use as rennet alternatives. Only C. procera and C. grandiflora latex fractions exhibited proteolytic and milk-clotting activities, which were not affected by high concentrations of NaCl and CaCl2. However, pre-incubation of both samples at 75 °C for 10 min eliminated completely their activities. Both proteolytic fractions were able to hydrolyze k-casein and to produce peptides of 16 kDa, a similar SDS-PAGE profile to commercial chymosin. RP-HPLC and mass spectrometry analyses of the k-casein peptides showed that the peptidases from C. procera or C. grandiflora hydrolyzed k-casein similar to commercial chymosin. The cheeses made with both latex peptidases exhibited yields, dry masses, and soluble proteins similar to cheeses prepared with commercial chymosin. In conclusion, C. procera and C. grandiflora latex peptidases with the ability to coagulate milk can be used as alternatives to commercial animal chymosin in the cheese manufacturing process.Centro de Investigación de Proteínas Vegetale

    DICOM’s Standardization in Histo-Pathology

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    Background: The Digital Imaging and Communications in Medicine (DICOM) standard helps to represent, store, and to exchange healthcare images associated with its data. DICOM develops over time and is continuously adapted to match the rigors of new clinical demands and technologies. An uphill battle in this regard is to conciliate new software programs with legacy systems. Methods: This work discusses the essential aspects of the standard and assesses its capabilities and limitations in a multisite, multivendor healthcare system aiming at Whole Slicing Image (WSI) procedures. Selected relevant DICOM attributes help to develop and organize WSI applications that extract and handle image data, integrated patient records, and metadata. DICOM must also interface with proprietary file formats, clinical metadata and from different laboratory information systems. Standard DICOM validation tools to measure encoding, storing, querying and retrieval of medical data can verify the generated DICOM files over the web. Results: This work investigates the current regulations and recommendations for the use of DICOM with WSI data. They rely mostly on the EU guidelines that help envision future needs and extensions based on new examination modalities like concurrent use of WSI with in-vitro imaging and 3D WSI. Conclusion: A DICOM file format and communication protocol for pathology has been defined. However, adoption by vendors and in the field is pending. DICOM allows efficient access and prompt availability of WSI data as well as associated metadata. By leveraging a wealth of existing infrastructure solutions, the use of DICOM facilitates enterprise integration and data exchange for digital pathology. In the future, the DICOM standard will have to address several issues due to the way samples are gathered and encompassing new imaging technologies

    Insights into milk-clotting activity of latex peptidases from <i>Calotropis procera</i> and <i>Cryptostegia grandiflora</i>

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    Latex fractions from Calotropis procera, Cryptostegia grandiflora, Plumeria rubra, and Himatanthus drasticus were assayed in order to prospect for new plant peptidases with milk-clotting activities, for use as rennet alternatives. Only C. procera and C. grandiflora latex fractions exhibited proteolytic and milk-clotting activities, which were not affected by high concentrations of NaCl and CaCl2. However, pre-incubation of both samples at 75 °C for 10 min eliminated completely their activities. Both proteolytic fractions were able to hydrolyze k-casein and to produce peptides of 16 kDa, a similar SDS-PAGE profile to commercial chymosin. RP-HPLC and mass spectrometry analyses of the k-casein peptides showed that the peptidases from C. procera or C. grandiflora hydrolyzed k-casein similar to commercial chymosin. The cheeses made with both latex peptidases exhibited yields, dry masses, and soluble proteins similar to cheeses prepared with commercial chymosin. In conclusion, C. procera and C. grandiflora latex peptidases with the ability to coagulate milk can be used as alternatives to commercial animal chymosin in the cheese manufacturing process.Centro de Investigación de Proteínas Vegetale
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