Effect of Deficit Irrigation on the Productive Response of Drip-irrigated Onion (Allium cepa L.) in Mediterranean Conditions

[EN] Water is an essential resource for food production, and agriculture consumes close to 69% of total freshwater use. Water shortage is becoming critical in arid and semiarid areas worldwide; therefore, it is vital to use water efficiently. The objective of this research was to evaluate the response of onion growth, plant water status, bulb yield, irrigation water use efficiency and bulb quality using three continued deficit strategies, applying 100, 75, and 50% of the irrigation water requirements during three seasons. The yield response factor was 0.71, indicating that in the analysed conditions the crop was tolerant to a water deficit. Compared to full irrigation, deficit irrigation with 75% of the irrigation water requirements resulted in a low yield and profit reduction for the growers (10.3% and 10.9%, respectively), but also important water savings (26.6%), improving both the irrigation water use efficiency and water use efficiency. However, onion exposure to severe water deficits at 50% of the irrigation water requirements drastically reduced plant growth and bulb yield and growers' profits, although it did increase their soluble solid content. Irrigating at 75% of the irrigation water requirements could be an actionable strategy for onion production under water-limited conditions.Abdelkhalik, A.; Pascual-Seva, N.; Nájera, I.; Domene, MA.; Baixauli Soria, C.; Pascual España, B. (2019). Effect of Deficit Irrigation on the Productive Response of Drip-irrigated Onion (Allium cepa L.) in Mediterranean Conditions. Horticulture Journal. 88(4):488-498. https://doi.org/10.2503/hortj.UTD-081S48849888

Antisense Phenotypes Reveal a Functional Expression of OsARF1, an Auxin Response Factor, in Transgenic Rice

OsARF1 is the first full-length member of auxin response factor (ARF) gene family to be cloned from monocot plant. Using quantitative RT-PCR this study found that, the transcript abundance of OsARF1 was significantly higher in embryonic tissues than in vegetative tissues. To investigate the effect of OsARF1 on the phenotype of rice, a cDNA fragment of OsARF1 was inserted in inverse orientation to the 35S promoter in vector pBin438 to produce an antisense (AS) construction. The AS-OsARF1 construct was transferred into rice (Oryza sativa L. japonica ) calli via Agrobacterium tumefaciens -mediated transformation. Molecular analysis of transgenic plants showed that the functional expression of OsARF1 was inhibited at mRNA level efficiently. The AS-OsARF1 plants showed extremely low growth, poor vigor, short curled leaves and tillered but were sterile. Therefore, the OsARF1 was shown to be essential for growth in vegetative organs and seed development

Nanostructured front electrodes for perovskite/c-Si tandem photovoltaics

The rise in the power conversion efficiency (PCE) of perovskite solar cells has triggered enormous interest in perovskite-based tandem photovoltaics. One key challenge is to achieve high transmission of low energy photons into the bottom cell. Here, nanostructured front electrodes for 4-terminal perovskite/crystalline-silicon (perovskite/c-Si) tandem solar cells are developed by conformal deposition of indium tin oxide (ITO) on self-assembled polystyrene nanopillars. The nanostructured ITO is optimized for reduced reflection and increased transmission with a tradeoff in increased sheet resistance. In the optimum case, the nanostructured ITO electrodes enhance the transmittance by ∼7% (relative) compared to planar references. Perovskite/c-Si tandem devices with nanostructured ITO exhibit enhanced short-circuit current density (2.9 mA/cm2 absolute) and PCE (1.7% absolute) in the bottom c-Si solar cell compared to the reference. The improved light in-coupling is more pronounced for elevated angle of incidence. Energy yield enhancement up to ∼10% (relative) is achieved for perovskite/c-Si tandem architecture with the nanostructured ITO electrodes. It is also shown that these nanostructured ITO electrodes are also compatible with various other perovskite-based tandem architectures and bear the potential to improve the PCE up to 27.0%

Soil application of effective microorganisms and nitrogen alleviates salt stress in hot pepper (Capsicum annum L.) plants

The application of effective microorganisms (EMs) and/or nitrogen (N) have a stimulating effect on plants against abiotic stress conditions. The aim of the present study was to determine the impact of the co-application of EMs and N on growth, physio-biochemical attributes, anatomical structures, nutrients acquisition, capsaicin, protein, and osmoprotectant contents, as well as the antioxidative defense system of hot pepper (Capsicum annum L.) plants. In the field trials, EMs were not applied (EMs-) or applied (EMs+) along with three N rates of 120, 150, and 180 kg unit N ha-1 (designated as N120, N150, and N180, respectively) to hot pepper plants grown in saline soils (9.6 dS m-1). The application of EMs and/or high N levels attenuated the salt-induced damages to hot pepper growth and yield. The application of EMs+ with either N150 or N180 increased the number, average weight and yield of fruits by 14.4 or 17.0%, 20.8 or 20.8% and 28.4 or 27.5%, respectively, compared to hot pepper plants treated with the recommended dose (EMs- × N150). When EMs+ was individually applied or combined with either N150 or N180, increased accumulation of capsaicin were observed by 16.7 or 20.8%, protein by 12.5 or 16.7%, proline by 19.0 or 14.3%, and total soluble sugars by 3.7 or 7.4%, respectively, in comparison with those treated with the integrative EMs- × N150. In addition, the non-enzymatic contents (ascorbate, and glutathione) and enzymatic activities (catalase, superoxide dismutase, and glutathione reductase) of the antioxidant defense systems significantly increased in hot pepper plants treated with EMs+ alone or combined with N150 or N180 under salt stress conditions. Higher accumulation of nutrients (N, P, K+, and Ca2+) along with reduced Na+ acquisition was also evidenced in response to EMs+ or/and high N levels. Most anatomical features of stems and leaves recovered in hot pepper plants grown in saline soils and supplied with EMs+ and N. The application of EMs and N is undoubtedly opening new sustainable approaches toward enhancing abiotic stress tolerance in crops (e.g. hot pepper)

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

On spacecraft magnetic attitude control

© 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. When using magnetorquers in attitude control system, satellites usually utilize magnetometers to measure the external magnetic field in the satellite environment, to compute the control command to the magnetorquers. This paper presents a magnetic control algorithm that eliminates the need for magnetometers in spacecraft attitude control with magnetorquers. During attitude maneiuvers, the measured system response to torque commands can be used to estimate the magnetic field. A Kalman fiter is used to estimate the magnetic field as well as the spacecraft angular velocities. The measurements are the spacecraft position and angular velocities. A model for the earth magnetic field is assumed available onboard the spacecraft. Model errors as well as measurements errors are simulated in this work. Simulation results show good attitude control performance

Active Power Filter

The proliferation of power electronics-based devices and equipment has significantly affected the power quality of the grid, which changes its sinusoidal nature through adding harmonic distortion. Power electronics applications have penetrated several venues in our life which increase the share of non-linear loads compared with linear loads, and hence degrades the power quality of the grid. Simultaneously, power electronics-based loads are sensitive to harmonic distortion. In order to cancel out or mitigate harmonics and their effects, active power filters, which will be discussed in this chapter, can be employed.Wiley Online librar