268 research outputs found

    A decision support system (GesCoN) for managing fertigation in vegetable crops. Part II-model calibration and validation under different environmental growing conditions on field grown tomato

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    The GesCoN model was evaluated for its capability to simulate growth, nitrogen uptake, and productivity of open field tomato grown under different environmental and cultural conditions. Five datasets collected from experimental trials carried out in Foggia (IT) were used for calibration and 13 datasets collected from trials conducted in Foggia, Perugia (IT), and Florida (USA) were used for validation. The goodness of fitting was performed by comparing the observed and simulated shoot dry weight (SDW) and N crop uptake during crop seasons, total dry weight (TDW), N uptake and fresh yield (TFY). In SDW model calibration, the relative RMSE values fell within the good 10-15% range, percent BIAS (PBIAS) ranged between -11.5 and 7.4%. The Nash-Sutcliffe efficiency (NSE) was very close to the optimal value 1. In the N uptake calibration RRMSE and PBIAS were very low (7%, and -1.78, respectively) and NSE close to 1. The validation of SDW (RRMSE = 16.7%; NSE = 0.96) and N uptake (RRMSE = 16.8%; NSE = 0.96) showed the good accuracy of GesCoN. A model under- or overestimation of the SDW and N uptake occurred when higher or a lower N rates and/or a more or less efficient system were used compared to the calibration trial. The in-season adjustment, using the "SDWcheck" procedure, greatly improved model simulations both in the calibration and in the validation phases. The TFY prediction was quite good except in Florida, where a large overestimation (+16%) was linked to a different harvest index (0.53) compared to the cultivars used for model calibration and validation in Italian areas. The soil water content at the 10-30 cm depth appears to be well-simulated by the software, and the GesCoN proved to be able to adaptively control potential yield and DW accumulation under limited N soil availability scenarios and consequently to modify fertilizer application. The DSSwell simulate SDW accumulation and N uptake of different tomato genotypes grown under Mediterranean and subtropical conditions

    Signal Alignment Problems on Multi-element X-Ray Fluorescence Detectors

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    X-ray fluorescence (XRF) is a spectroscopic technique with applications in several fields, such as biology, food science and forensics. Often setups have multi-element detectors in order to improve the signal-to-noise ratio. The relative set of produced spectra have to be aligned to a reference spectrum, in a procedure that is referred to as energy calibration, which is necessary for the fitting. Automated methods fail and a manual procedure is typically employed instead. In this paper, we discuss the signal alignment problem of such systems and we illustrate the preliminary results of a new automated method for linear XRF spectra alignment, which potentially can be used also for other time-series like data

    Antagonistic effect of Lactobacillus strains against gas-producing coliforms isolated from colicky infants

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    <p>Abstract</p> <p>Background</p> <p>Infantile colic is a common disturb within the first 3 months of life, nevertheless the pathogenesis is incompletely understood and treatment remains an open issue. Intestinal gas production is thought to be one of the causes of abdominal discomfort in infants suffering from colic. However, data about the role of the amount of gas produced by infants' colonic microbiota and the correlation with the onset of colic symptoms are scanty. The benefit of supplementation with lactobacilli been recently reported but the mechanisms by which they exert their effects have not yet been fully defined. This study was performed to evaluate the interaction between <it>Lactobacillus </it>spp. strains and gas-forming coliforms isolated from stools of colicky infants.</p> <p>Results</p> <p>Strains of coliforms were isolated from stools of 45 colicky and 42 control breastfed infants in McConkey Agar and identified using PCR with species-specific primers, and the BBLℱ Enterotubeℱ II system for <it>Enterobacteriaceae</it>. Gas-forming capability of coliforms was assessed in liquid cultures containing lactose as sole carbon source. The average count of total coliforms in colicky infants was significantly higher than controls: 5.98 (2.00-8.76) log<sub>10 </sub><it>vs </it>3.90 (2.50-7.10) CFU/g of faeces (p = 0.015). The following strains were identified: <it>Escherichia coli</it>, <it>Klebsiella pneumoniae</it>, <it>Klebsiella oxytoca</it>, <it>Enterobacter aerogenes</it>, <it>Enterobacter cloacae </it>and <it>Enterococcus faecalis</it>. Then, 27 <it>Lactobacillus </it>strains were tested for their antagonistic effect against coliforms both by halo-forming method and in liquid co-cultures. <it>Lactobacillus delbrueckii </it>subsp.<it>delbrueckii </it>DSM 20074 and <it>L. plantarum </it>MB 456 were able to inhibit all coliforms strains (halo-forming method), also in liquid co-cultures, thus demonstrating an antagonistic activity.</p> <p>Conclusions</p> <p>This study shows that two out of 27 strains of <it>Lactobacillus </it>examined possess an antimicrobial effect against six species of gas-forming coliforms isolated from colicky infants. Our findings may stimulate new researches to identify which <it>Lactobacillus </it>strains can improve colicky symptoms by acting on coliforms gut colonization.</p

    Potential physiological stress biomarkers in human sweat

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    Emotional sweating occurs in response to affective stimuli like fear, anxiety, or stress and is more evident in specific parts of the body such as the palms, soles, and axillae. During emotional sweating, humans release many volatile organic compounds (VOCs) that could play a crucial role as possible com-municative signals of specific emotions. In this preliminary study, we investigated seven volatiles belonging to the chemical class of acids and released from the armpit as possible stress biomarkers. To this aim, we processed sweat VOCs and physiological stress correlates such as heart rate variability (HRV), electrodermal activity, and thermal imaging during a Stroop color-word test. Particularly, we modelled the variability of well-known stress markers extracted from the physiological signals as a function of the acid VOCs by means of LASSO regression. LASSO results revealed that the dodecanoic acid was the only selected regressor and it was able to significantly explain more than 64 % of the variance of both the mean temperature of the tip of the nose (p=0.018, R2=0.64) and of the mean HRV (p=0.011, R2=0.67). Although preliminary, our results suggest that dodecanoic acid could be a marker of the sympathetic nervous system response to stress stimuli, opening for the detection of new biomarkers of stress

    Chemical composition and bioactive properties of Cichorium spinosum L. in relation to nitrate/ammonium nitrogen ratio

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    Nitrogenous fertilizers may affect the yield and quality of leafy vegetables via the application rate and nitrogen form. In the present study, the effect of the nitrate:ammonium nitrogen ratio in the nutrient solution on the chemical composition and bioactive properties of Cichorium spinosum leaves was evaluated. For this purpose, C. spinosum plants were fertigated with nutrient solution containing different ratios of nitrate: ammonium nitrogen: (i) 100:0 NO3-N:NH4-N; (ii) 75:25 NO3-N:NH4-N; (iii) 50:50 NO3-N:NH4-N; (iv) 25:75 NO3-N:NH4-N; and (v) 0:100 NO3-N:NH4-N of total nitrogen; aswell as (vi) 100% ureic nitrogen. RESULTS: The only detected tocopherol isoforms were - and -tocopherol, which were positively affected by nitrate nitrogen (100:0 NO3-N:NH4-N). Similar results were observed for individual and total organic acids. The main detected sugars were fructose, glucose and sucrose, with a varied effect of nutrient solution composition on their content, whereas total sugar concentrationwas positively affected by a balanced or a slightly increased proportion of NH4-N (50:50 and 25:75 NO3-N:NH4-N). The fatty acids profile was beneficially affected by the highest NH4-N ratio (0:100 NO3-N:NH4-N), whereas higher amounts of NO3 − than NH4 + nitrogen (75:25 NO3-N:NH4-N) resulted in a higher content of total phenolic compounds. Finally, no cytotoxic effects were observed against non-tumor (PLP2, HeLa) and tumor (HepG2, MCF-7, NCI-H460) cell lines for any of the studied nutrient solutions. CONCLUSION: The modulation ofNO3-N:NH4-N ratio in the nutrient solution supplied to C. spinosummay enhance the content of desirable health-promoting compounds and reduce the content of antinutrients, thus increasing the overall quality of the final product without compromising yield. © 2019 Society of Chemical IndustryWe are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019), L. Barros, A. Fernandes and R. C. Calhelha’s contract. The authors are grateful to the FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

    Zinc biofortification through seed nutri-priming using alternative zinc sources and concentration levels in pea and sunflower microgreens

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    Micronutrient deficiencies caused by malnutrition and hidden hunger are a growing concern worldwide, exacerbated by climate change, COVID-19, and conflicts. A potentially sustainable way to mitigate such challenges is the production of nutrient-dense crops through agronomic biofortification techniques. Among several potential target crops, microgreens are considered suitable for mineral biofortification because of their short growth cycle, high content of nutrients, and low level of anti-nutritional factors. A study was conducted to evaluate the potential of zinc (Zn) biofortification of pea and sunflower microgreens via seed nutri-priming, examining the effect of different Zn sources (Zn sulfate, Zn-EDTA, and Zn oxide nanoparticles) and concentrations (0, 25, 50, 100, and 200 ppm) on microgreen yield components; mineral content; phytochemical constituents such as total chlorophyll, carotenoids, flavonoids, anthocyanin, and total phenolic compounds; antioxidant activity; and antinutrient factors like phytic acid. Treatments were arranged in a completely randomized factorial block design with three replications. Seed soaked in a 200 ppm ZnSO4 solution resulted in higher Zn accumulation in both peas (126.1%) and sunflower microgreens (229.8%). However, an antagonistic effect on the accumulation of other micronutrients (Fe, Mn, and Cu) was seen only in pea microgreens. Even at high concentrations, seed soaking in Zn-EDTA did not effectively accumulate Zn in both microgreens’ species. ZnO increased the chlorophyll, total phenols, and antioxidant activities compared to Zn-EDTA. Seed soaking in ZnSO4 and ZnO solutions at higher concentrations resulted in a lower phytic acid/Zn molar ratio, suggesting the higher bioaccessibility of the biofortified Zn in both pea and sunflower microgreens. These results suggest that seed nutrient priming is feasible for enriching pea and sunflower microgreens with Zn. The most effective Zn source was ZnSO4, followed by ZnO. The optimal concentration of Zn fertilizer solution should be selected based on fertilizer source, target species, and desired Zn-enrichment level

    Agronomic, physiological and quality response of romaine and red oak-leaf lettuce to nitrogen input

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    Protecting the environment by improving the crop-system nitrogen (N) use efficiency (NUE) while maximising yield and quality is a primary challenge for modern agriculture, and understanding the processes that govern N fluxes in the plant-soil system is essential to improve NUE. An on-farm study was conducted over two fall-winter seasons to evaluate the NUE, agronomical and physiological response of romaine (var. longifolia, cv Manavert) and red oak-leaf (var. crispa, cv Aruba) lettuce (Lactuca sativa L.) to different N-rates (0, 60, 120, 180 kg ha–1 of N). Nitrogen rate influenced all tested parameters, including plant fresh and dry weight, N accumulation, leaf NO3– and dry matter content, NUE indices, N nutrition index (NNI), soil residual N and the estimated N losses at the end of the crop season. Fresh yield, dry weight and N-accumulation response to N rate were influenced by lettuce genotype. Manavert had higher N recovery, NUE, and lower leaf NO3– concentration than Aruba. Analysing the NNI overtime, 120 kg ha–1 of N assured an optimal N status in both Manavert and Aruba, while N deficiency and excess were observed at lower and higher N-rates, respectively. An empirical relationship was observed between NNI and leaf NO3– concentration, suggesting that leaf NO3– concentration may be used to predict NNI and thus the crop N status. The relationship between NNI and leaf NO3– concentration may be used to define optimal leaf NO3– concentration ranges for the rapid and site-specific assessment of the crop N status, and the dynamic adjustment of N-fertilisation, contributing to improve crop NUE, minimise N-losses, and optimise yield and quality of lettuce crops

    The compositional aspects of edible flowers as an emerging horticultural product

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    Edible flowers are becoming very popular, as consumers are seeking healthier and more attractive food products that can improve their diet aesthetics and diversify their dietary sources of micronutrients. The great variety of flowers that can be eaten is also associated with high variability in chemical composition, especially in bioactive compounds content that may significantly contribute to human health. The advanced analytical techniques allowed us to reveal the chemical composition of edible flowers and identify new compounds and effects that were not known until recently. Considering the numerous species of edible flowers, the present review aims to categorize the various species depending on their chemical composition and also to present the main groups of compounds that are usually present in the species that are most commonly used for culinary purposes. Moreover, special attention is given to those species that contain potentially toxic or poisonous compounds as their integration in human diets should be carefully considered. In conclusion, the present review provides useful information regarding the chemical composition and the main groups of chemical compounds that are present in the flowers of the most common species.info:eu-repo/semantics/publishedVersio

    Eudragit s100 entrapped liposome for curcumin delivery: Anti-oxidative effect in Caco-2 cells

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    Curcumin is a natural polyphenol with strong antioxidant activity. However, this molecule shows a very poor bioavailability, instability, and rapid metabolism in vivo. In this work curcumin was loaded in Eudragit-coated liposomes to create a gastroresistant carrier, able to protect its load from degradation and free it at the site of absorption in the colon region. Small unilamellar vesicles were prepared and coated with Eudragit by a pH-driven method. The physico-chemical properties of the prepared systems were assessed by light scattering, transmission electron microscopy, infrared spectroscopy, and differential scanning calorimetry. The uptake of vesicles by Caco-2 cells and the anti-oxidant activity in cells were evaluated. The produced vesicles showed dimensions of about forty nanometers that after covering with Eudragit resulted to have micrometric dimensions at acid pH. The experiments showed that at pH &gt; 7.0 the polymeric coating dissolves, releasing the nanometric liposomes and allowing them to enter Caco-2 cells. Delivered curcumin loaded vesicles were then able to decrease significantly ROS levels as induced by H2O2 in Caco-2 cells. The proposed work showed the possibility of realizing effective gastroresistant curcumin liposome formulations for the delivery of antioxidant molecules to Caco-2 cells, potentially applicable to the treatment of pathological conditions related to intestinal oxidative stress. View Full-Tex

    HACKATHON - OpenGeodata per la città, il territorio, l’ambiente e il paesaggio

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    Nell’ambito dell'International Open data day Italia 2014 il DIST ha organizzato un hackathon dedicato alle tematiche di ricerca, esplorazione e utilizzazione di dati geospaziali open, da elaborare con strumenti GIS per produrre analisi e rispondere a domande di conoscenza relative ai temi di città, territorio, ambiente e paesaggio. La giornata si inserisce nell’ambito dell’attivo dibattito culturale relativo agli open data e agli open dati geografici in particolare, tema molto sentito in questo periodo dalla comunità scientifica
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