13 research outputs found

    New strategies to overcome water limitation in cultivated maize: Results from sub-surface irrigation and silicon fertilization

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    The increasing growth of the world's population has established an unprecedented pressure in the availability of fresh water resources, with food production systems consuming over 70% of the world's fresh water withdrawals. Other pressures include climate change effects and the increasing number of semi-arid regions. The present challenges are therefore the maintenance of high production rates with fewer resources, especially in regions where water is becoming less accessible. In this study, we have tested the effect of sub-surface irrigation and silicon fertilization in maize growth with and without water limitation. These solutions have been suggested as effective in drought conditions but an overall study of their effects on the soil water balance and root length density is lacking. We have conducted a pot experiment with maize for 101 days where measurements in soil water content and root length were taken. Also, Hydrus 2-D was used to simulate the root water uptake and calculate the water balance. Results show that both sub-surface irrigation and silicon fertilization increase the root system by 21% and 34% respectively in water stress situation. Also, in the case of no water stress, silicon fertilization still induces an increase of 11% in the root development, showing that this solution has positive effects even when the crop is not hydrologically limited. Indeed the root water uptake was higher for the silicon treatment when no water limitation was present (71.6 L), compared to the sub-surface irrigation (62.5 L) and the control (62.3 L). While sub-surface irrigation generally decreased evaporation, the silicon treatment lowered drainage by promoting a better and more efficient root water uptake.info:eu-repo/semantics/publishedVersio

    Quality evaluation of groundwater resources of Ardabil aquifer for agricultural and drinking uses

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    In this study, groundwater of Ardabil aquifer quality in terms of drinking and agricultural, was evaluated. For this purpose, 76 wells including 32 drinking wells and 44 agricultural wells were considered. The results indicated that groundwater quality on the Water Quality Index (WQI) is in good condition. Based on the standards of the World Health Organization (WHO) and Institute of Standard and Industrial Research of Iran (ISIRI), 10.5 percent of the wells have nitrate levels above the limit in the wet season; but in the dry season, about 29 percent of the wells had nitrate values higher than allowable level. In order to assess the quality of groundwater for agricultural use, as well as the Wilcox diagram and other parameters of sedimentation and corrosion including: Langelier saturation index (LSI), Ryznar Index (RSI) and Puckorius (POR), magnesium hazard (MH), permeability (I), the remaining sodium percentage (RSC), sodium adsorption ratio (SAR) and the percentage of sodium and chlorine were used. The results showed groundwater of this aquifer are corrosive and use it in urban water supply systems, causing illness and various problems caused by corrosion of pipes and the, the human will. The use of these waters, for agricultural purposes will cause problems in metal fittings of sprinkler irrigation systems

    Therapeutic Options and Critical Care Strategies in COVID-19 Patients; Where Do We Stand in This Battle?

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    A pandemic of COVID-19 made an appearance in Wuhan, China, in late December 2019 and rapidly became a serious concern worldwide, with killing more than 238000 people until 3rd May 2020. Given the fact that a vaccine against the virus probably won’t be available anytime in the near future, the therapeutic strategies have become more prominent. Many supposedly effective drugs are under evaluation which may hinder the replication of SARS-CoV-2, and subsequently the infection. Lately on 1th may 2020, FDA authorized the use of experimental drug, Remdesivir for "emergency purpose" in COVID-19 cases. Chloroquine and hydroxychloroquine, among the very first under-trial drugs, have been revealed to have promising impacts in treatment of SARS-CoV2. Broad-spectrum antivirals as well as HIV protease-inhibitors are still subject to assessment. Particularly angiotensin-converting enzyme 2 (ACE2) inhibitors are increasingly taken into consideration because of ACE2 being recognized as a host-cell receptor for COVID-19. Immune-Enhancement therapy by Interferons and Intravenous immunoglobulin (IVIG) has been shown to be effective in some cases. Moreover, Convalescent Plasma Therapy and auxiliary blood purification were considered as the treatment of SARS-CoV2 infection. Among the critically ill patients, Oxygen-therapy, timely usage of inflammatory inhibitors, and controlling viral shedding by antivirals may reduce the mortality and morbidity of COVID-19

    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project 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; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

    National, sub-national, and risk-attributed burden of thyroid cancer in Iran from 1990 to 2019

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    An updated exploration of the burden of thyroid cancer across a country is always required for making correct decisions. The objective of this study is to present the thyroid cancer burden and attributed burden to the high Body Mass Index (BMI) in Iran at national and sub-national levels from 1990 to 2019. The data was obtained from the GBD 2019 study estimates. To explain the pattern of changes in incidence from 1990 to 2019, decomposition analysis was conducted. Besides, the attribution of high BMI in the thyroid cancer DALYs and deaths were obtained. The age-standardized incidence rate of thyroid cancer was 1.57 (95% UI: 1.33–1.86) in 1990 and increased 131% (53–191) until 2019. The age-standardized prevalence rate of thyroid cancer was 30.19 (18.75–34.55) in 2019 which increased 164% (77–246) from 11.44 (9.38–13.85) in 1990. In 2019, the death rate, and Disability-adjusted life years of thyroid cancer was 0.49 (0.36–0.53), and 13.16 (8.93–14.62), respectively. These numbers also increased since 1990. The DALYs and deaths attributable to high BMI was 1.91 (0.95–3.11) and 0.07 (0.04–0.11), respectively. The thyroid cancer burden and high BMI attributed burden has increased from 1990 to 2019 in Iran. This study and similar studies’ results can be used for accurate resource allocation for efficient management and all potential risks’ modification for thyroid cancer with a cost-conscious view

    On the Modeling of an Open Channel MEMS Based Capacitive Flow Sensor

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    In this paper an open channel MEMS capacitive flow sensor has been designed based on a microplate deflection measuring. Proposed flow sensor consists with two separate units, one for sensing the static fluid pressure and the other for sensing the fluid static and dynamic pressure. The governing equation whose solution holds the answer to all our questions about the sensor’s characteristics is a nonlinear elasto-electrostatic equation. Sensor’s static response and mechanical behavior of the sensing elements in a channel have been simulated numerically by using of Step by Step Linearization Method. The sensor stability has been examined and the stable region of the sensor has been studied. The effect of fluid velocity and static pressure on stability limit of the sensor has been investigated and the effect of bias voltage on sensor sensitivity has been studied

    Effects of Partial Root-Zone Irrigation on the Water Use Efficiency and Root Water and Nitrate Uptake of Corn

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    Due to water shortages and the increasing need for food in recent years, the optimization of water consumption parameters, fertilizers, and food production are essential and a priority. The aim of this study is to investigate the effect of partial root-zone irrigation (PRI) methods on corn plant characteristics. The study also tried to measure the water use efficiency (WUE) of corn in pot cultivation and provide the best method of management in the fields of irrigation and fertigation. For this purpose, three irrigation methods, including alternate partial root-zone irrigation (APRI), fixed partial root-zone irrigation (FPRI), and conventional irrigation (CI) were studied in pots, and completely randomized blocks with eight replications were carried out. Each pot was evenly separated with plastic sheets into two sub-parts of equal volume, between which no water exchange occurred. The water content of the field capacity was calculated by the weighting method. The water requirement was provided daily, equal to 95% of the field capacity water content. Parameters including shoot and root dry weight, nitrate (N) uptake, the remaining nitrate in the soil, leaf area index, and WUE during the growing season were measured and compared. According to the results, the amount of saved water using the FPRI and APRI methods compared to the CI method were 28% and 32%, respectively. The highest and lowest WUE were observed as equal to 4.88 and 3.82 g/L using the APRI and CI methods, respectively, among which the CI method had the highest yield according to the amount of utilized water. Given the statistical examinations, there was no significant difference in the nitrate level of plants between CI and APRI, and the lowest uptake was observed in FPRI. Finally, considering indicators of yield production and WUE simultaneously, the APRI method was selected as the best method of management

    Biofertilizers and Silicon Fertilization as a Sustainable Option for Maize Production

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    Due to the rapid growth of human population and increasing living standards, there is a continuous increase in the gap between food productivity and demand. At the same time there is a global reduction in freshwater availability for agriculture. Several options have been proposed along the way to increase water use efficiency in the field. One promising possibility is the adoption of fertilization with silicon (Si) combined with biofertilizers (microorganisms). Si is estimated to impact on the root volume and distribution, while microorganisms added to the soil in the rhizosphere also impact directly on root growth. In this work we have tested the influence of Si fertilization (magnesium silicate + diatomaceous earth) combined with biofertilizers and 20% reduction in NPK fertilization in the growth of maize and the soil water balance on a field trial located in Companhia das Lezírias (Portugal). Data on soil water content was collected regularly and root analysis was performed at harvest. The water balance was calculated through the model HYDRUS, using root growth model calibrated for maize in the present conditions. Results showed that using an alternative source of fertilization (Si+microbes) while reducing NPK fertilization impacted on root growth development, with roots growing more horizontally, while conventional NPK fertilization resulted in deeper roots. As a consequence,, root water uptake increased and evaporation losses were lower in the treatment supplemented compared to the conventional, without compromising the yield obtained. Using biofertilizers combined with Si sources resulted in higher water use efficiency (2.64 kg m −3 ) than the NPK fertilization, normally applied for maize growth (2.56 kg m−3 ). The results imply that the supplementation+biofertilization allows a potential saving of 206 m 3 ha −1 water and 157 kg NPK ha −1 fertilization in a growing season assuring the same yield as obtained with the conventional NPK fertilization (18.64 ton ha −1 ). Implications are important for Portuguese agriculture, where maize is one of the most important cereals cultivated, especially in Centre and Southern part of the country where water is a scarce resource.info:eu-repo/semantics/acceptedVersio
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