scholarly journals Different Zn loading in Urea–Formaldehyde influences the N controlled release by structure modification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amanda S. Giroto ◽  
Stella F. do Valle ◽  
Gelton G. F. Guimarães ◽  
Nicolai D. Jablonowski ◽  
Caue Ribeiro ◽  
...  
Keyword(s):  
Urea Formaldehyde ◽  
Critical Role ◽  
Critical Factor ◽  
Crop Productivity ◽  
Polymeric Chain ◽  
High Concentration ◽  
Agronomic Efficiency ◽  
Beneficial Effects ◽  
N Release ◽  
N Volatilization

AbstractNitrogen fertilization has been a critical factor for high crop productivity, where urea is currently the most used N source due to its high concentration and affordability. Nevertheless, urea fast solubilization leads to frequent losses and lower agronomic efficiency. The modification of urea structure by condensation with formaldehyde has been proposed to improve nutrient uptake by plants and to reduce environmental losses. Herein we show that the co-formulation with Zn strongly modifies the N release (in lab conditions) and, more important, the Zn source—ZnSO4 or ZnO—has a critical role. Urea–formaldehyde (UF) served as a matrix for the zinc sources, and chemical characterizations revealed that Zn particles influenced the length of the polymeric chain formation. Release tests in an aqueous medium showed that the UF matrix favors ZnO release and, on the other hand, delays ZnSO4 delivery. Soil incubation with the fertilizer composites proved the slow-release of N from UF, is ideal for optimizing nutritional efficiency. Our results indicated that the ZnO-UF system has beneficial effects for both nutrients, i.e., reduces N volatilization and increases Zn release.

scholarly journals Different Zn Loading in Urea-Formaldehyde Influences the N Controlled Release by Structure Modification

2021 ◽  
Author(s):  
Amanda S. Giroto ◽  
Stella F. Valle ◽  
Gelton G. F. Guimaraes ◽  
Nicolai D. Jablonowski ◽  
Caue Ribeiro ◽  
...  
Keyword(s):  
Urea Formaldehyde ◽  
Critical Role ◽  
Critical Factor ◽  
Crop Productivity ◽  
High Concentration ◽  
Agronomic Efficiency ◽  
Beneficial Effects ◽  
N Release ◽  
Polymeric Chains ◽  
N Volatilization

Abstract Nitrogen fertilization has been a critical factor for high crop productivity, where urea is currently the most used N source due to its high concentration and affordability. Nevertheless, urea fast solubilization leads to frequent losses and lower agronomic efficiency. The modification of urea structure by condensation with formaldehyde has been proposed to improve nutrient uptake by plants and to reduce environmental losses. Herein we show that the co-formulation with Zn strongly modifies the N release (in lab conditions) and, more important, the Zn source – ZnSO4 or ZnO – has a critical role. Urea-formaldehyde (UF) served as a matrix for the zinc sources, whose chemical characterizations revealed that Zn particles influenced the length of the polymeric chains' formation. Release tests in an aqueous medium showed that the UF matrix favors ZnO release and, on the other hand, delays ZnSO4 delivery. Soil incubation with the fertilizer composites proved the slow-release of N from UF, ideal for optimizing nutritional efficiency. Our results indicated that ZnO: UF system has beneficial effects for both nutrients, i.e., reduces N volatilization and increases Zn release.

scholarly journals Biochar Derived from the Dry, Solid Fraction of Pig Manure as Potential Fertilizer for Poor and Contaminated Soils

2017 ◽  
Vol 6 (2) ◽  
pp. 167 ◽  
Author(s):  
Jens Maggen ◽  
Robert Carleer ◽  
Jan Yperman ◽  
Alain De Vocht ◽  
Sonja Schreurs ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Slow Release ◽  
Low Cost ◽  
Agricultural Waste ◽  
Value Added ◽  
Crop Productivity ◽  
Pig Manure ◽  
High Concentration ◽  
Beneficial Effects ◽  
Viable Approach

Pig manure results in the release of NH3, NOx, volatile organic compounds and odour nuisance. Pyrolysis of dried pig manure can be considered as an economical viable approach converting this agricultural waste into value added products. The produced amendment biochar can be used as a slow release fertilizer with high concentration of N, K and P and has beneficial effects as carbon sequester and improver of soil quality and crop productivity. It is proved that a 2 wt.% blending of biochar with a poor soil affects positively plant growth and crops (dwarf beans), and worm (Eisenia fetida) survival and production. Additional, available heavy metals are immobilised in the biochar and not leachable. The resulting biochar therefore offers prospects as low cost, slow release soil conditioner and fertiliser for a long term effect.

Comparative Advantage of Using Biopesticides in Ukrainian Agroecosystems

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Hasrat Arjjumend ◽  
Konstantia Koutouki ◽  
Olga Donets
Keyword(s):  
Shelf Life ◽  
Crop Production ◽  
Plant Protection ◽  
Agricultural Practices ◽  
Crop Productivity ◽  
Poor Quality ◽  
Soil Biology ◽  
Chemical Contamination ◽  
High Concentration ◽  
Irreversible Damage

The use of unsustainable levels of chemical fertilizers and plant protection chemicals has resulted in a steady decline in soil and crop productivity the world over. Soil biology has undergone irreversible damage, coupled with a high concentration of toxic chemical residues in plant tissues and human bodies. Agricultural practices must evolve to sustainably meet the growing global demand for food without irreversibly damaging soil. Microbial biocontrol agents have tremendous potential to bring sustainability to agriculture in a way that is safe for the environment. Biopesticides do not kill non-target insects, and biosafety is ensured because biopesticides act as antidotes and do not lead to chemical contamination in the soil. This article is part of a larger study conducted in Ukraine by researchers at the Université de Montréal with the support of Mitacs and Earth Alive Clean Technologies. The responses of farmers who use biofertilizers (“user farmers”) and those who do not (“non-user farmers”), along with the responses of manufacturers or suppliers of biofertilizers, and research and development (R&D) scientists are captured to demonstrate the advantages of applying microbial biopesticides to field crops. Participants reported a 15-30% increase in yields and crop production after the application of biopesticides. With the use of biopesticides, farmers cultivated better quality fruits, grains, and tubers with a longer shelf life. Moreover, while the risk of crop loss remains high (60-70%) with chemically grown crops, this risk is reduced to 33% on average if crops are grown using biopesticides. The findings indicate that a large proportion of farmers would prefer to use biopesticides if they are effective and high quality products. In this context, the quality and effectiveness of products is therefore very important. Despite their benefits to soil, human health, and ecosystems, biopesticides face significant challenges and competition vis-à-vis synthetic pesticides for a variety of reasons. Therefore, the development of biopesticides must overcome the problems of poor quality products, short shelf life, delayed action, high market costs, and legal/registration issues.

scholarly journals A Genome-Wide Screen in Saccharomyces cerevisiae Reveals a Critical Role for Oxidative Phosphorylation in Cellular Tolerance to Lithium Hexafluorophosphate

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 888
Author(s):  
Xuejiao Jin ◽  
Jie Zhang ◽  
Tingting An ◽  
Huihui Zhao ◽  
Wenhao Fu ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oxidative Phosphorylation ◽  
Cellular Response ◽  
Critical Role ◽  
Lithium Ion ◽  
Deletion Mutants ◽  
High Concentration ◽  
Genome Wide ◽  
A Genome ◽  
Lithium Hexafluorophosphate

Lithium hexafluorophosphate (LiPF6) is one of the leading electrolytes in lithium-ion batteries, and its usage has increased tremendously in the past few years. Little is known, however, about its potential environmental and biological impacts. In order to improve our understanding of the cytotoxicity of LiPF6 and the specific cellular response mechanisms to it, we performed a genome-wide screen using a yeast (Saccharomyces cerevisiae) deletion mutant collection and identified 75 gene deletion mutants that showed LiPF6 sensitivity. Among these, genes associated with mitochondria showed the most enrichment. We also found that LiPF6 is more toxic to yeast than lithium chloride (LiCl) or sodium hexafluorophosphate (NaPF6). Physiological analysis showed that a high concentration of LiPF6 caused mitochondrial damage, reactive oxygen species (ROS) accumulation, and ATP content changes. Compared with the results of previous genome-wide screening for LiCl-sensitive mutants, we found that oxidative phosphorylation-related mutants were specifically hypersensitive to LiPF6. In these deletion mutants, LiPF6 treatment resulted in higher ROS production and reduced ATP levels, suggesting that oxidative phosphorylation-related genes were important for counteracting LiPF6-induced toxicity. Taken together, our results identified genes specifically involved in LiPF6-modulated toxicity, and demonstrated that oxidative stress and ATP imbalance maybe the driving factors in governing LiPF6-induced toxicity.

scholarly journals 1-D Air-snowpack modeling of atmospheric nitrous acid at South Pole during ANTCI 2003

2008 ◽  
Vol 8 (23) ◽  
pp. 7087-7099 ◽  
Author(s):  
W. Liao ◽  
D. Tan
Keyword(s):  
Liquid Layer ◽  
Molecular Diffusion ◽  
Volume Ratio ◽  
Critical Factor ◽  
Snow Surface ◽  
High Concentration ◽  
Nitrite Concentration ◽  
Mechanical Dispersion ◽  
Quasi Liquid Layer ◽  
D Model

Abstract. A 1-D air-snowpack model of HONO has been developed and constrained by observed chemistry and meteorology data. The 1-D model includes molecular diffusion and mechanical dispersion, windpumping in snow, gas phase to quasi-liquid layer phase HONO transfer and quasi-liquid layer nitrate and interstitial air HONO photolysis. Photolysis of nitrate is important as a dominant HONO source inside the snowpack, however, the observed HONO emission from the snowpack was triggered mainly by the equilibrium between quasi liquid layer nitrite and firn air HONO deep down the snow surface (i.e. 30 cm below snow surface). The high concentration of HONO in the firn air is subsequently transported above the snowpack by diffusion and windpumping. The model uncertainties come mainly from lack of measurements and the interpretation of the QLL properties based on the bulk snow measurements. One critical factor is the ionic strength of QLL nitrite, which is estimated here by the bulk snow pH, nitrite concentration, and QLL to bulk snow volume ratio.

Cyclosporine increases ischemia-induced endothelial progenitor cell mobilization through manipulation of the CD26 system

2008 ◽  
Vol 294 (3) ◽  
pp. R811-R818 ◽  
Author(s):  
Chao-Hung Wang ◽  
Wen-Jin Cherng ◽  
Ning-I Yang ◽  
Chia-Ming Hsu ◽  
Chi-Hsiao Yeh ◽  
...  
Keyword(s):  
Critical Role ◽  
Serum Levels ◽  
Blood Levels ◽  
Short Term ◽  
Endothelial Progenitor ◽  
Beneficial Effects ◽  
Dpp Iv ◽  
Before And After ◽  
Cell Mobilization

Cyclosporin A (CsA) improves the success rate of transplantation. The CD26/dipeptidylpeptidase IV (DPP IV) system plays a critical role in mobilizing endothelial progenitor cells (EPCs) from bone marrow. This study investigated whether CsA manipulates CD26/DPP IV activity and increases EPC mobilization. C57BL/6 mice were divided into control and CsA-treated groups. Before and after hindlimb ischemia was induced, circulating EPC number and serum levels of different cytokines were measured. Compared with the controls, CsA treatment significantly increased the blood levels of stroma-derived factor-1α and stem cell factor after ischemic stress ( P < 0.001). The CsA group displayed a significant increase in the number of circulating EPCs (sca-1+KDR+ and c-kit+CD31+ EPCs, both P < 0.05). In vivo, CsA caused a significant increase in the numbers of EPCs incorporated into the Matrigel and ischemic limbs ( P < 0.05). In the peripheral blood, CsA significantly decreased CD26+ cell numbers and attenuated the plasma CD26/DPP IV activity ( P < 0.001). Furthermore, short-term CsA treatment significantly improved the perfusion of ischemic limbs and decreased the spontaneous digital amputation rate. In summary, CsA manipulates the mobilization of EPCs into the circulation via the CD26/DPP IV system. Short-term CsA treatment has beneficial effects on angiogenesis of ischemic tissues.

Juggling on the line

2015 ◽  
Vol 37 (4) ◽  
pp. 459-474 ◽  
Author(s):  
Samantha Evans
Keyword(s):  
Critical Role ◽  
Case Study Research ◽  
Critical Factor ◽  
Employee Relations ◽  
Front Line ◽  
Structured Interviews ◽  
Line Managers ◽  
Content Type ◽  
Nuanced Understanding ◽  
High Level

Purpose – The purpose of this paper is to examine the interplay between the role of front line managers (FLMs) and their contribution to the reported gap between intended and actual human resource management (HRM). Design/methodology/approach – The findings draw on case study research using 51 semi-structured interviews with managers across two UK retail organisations between 2012 and 2013. Findings – This paper argues that FLMs are key agents in people management and play a critical role in the gap between intended and actual employee relations (ER) and HRM. The research found that these managers held a high level of responsibility for people management, but experienced a lack of institutional support, monitoring or incentives to implement according to central policy. This provided an opportunity for them to modify or resist intended policy and the tensions inherent in their role were a critical factor in this manipulation of their people management responsibilities. Research limitations/implications – The data were collected from only one industry and two organisations so the conclusions need to be considered within these limitations. Practical implications – Efforts to address the gap between intended and actual ER/HRM within organisations will need to consider the role tensions of both front line and middle managers. Originality/value – This research provides a more nuanced understanding of the interplay between FLMs and the gap between intended and actual HRM within organisations. It addresses the issue of FLMs receiving less attention in the HRM-line management literature and the call to research their role in the translation of policy into practice.

Directional manipulation of diffusio-osmosis flow by design of solute-wall and solvent-wall interactions

2021 ◽  
Author(s):  
Xin Wang ◽  
Dengwei Jing
Keyword(s):  
Critical Role ◽  
Liquid Interface ◽  
High Concentration ◽  
Interfacial Layers ◽  
Fluidic Devices ◽  
Wall Interaction ◽  
Dynamics Simulations ◽  
External Forces ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract Understanding of the diffusio-osmosis, the flow induced by a solute gradient acting in narrow interfacial layers at nanoscale solid-liquid interface, is of great value in view of the increasing importance of micro- and nano-fluidic devices and self-propelling particle. Here, using molecular dynamics simulations, we develop a numerical method for direct simulation of diffusio-osmosis flows mimicking the realistic experiment without any assumed external forces. It allows us to obtain reliable flow details which is however hard to get in experiments. We found that the solvent-wall interaction, previously overlooked in classical paradigm, plays a critical role in diffusio-osmosis process. In particular, diffusio-osmosis is controlled by the interaction difference between solute-wall and solvent-wall. When solute-than solvent-wall, a surface excess (depletion) of solute particles on solid-liquid interface is formed which induces diffusio-osmosis flow towards low (high) concentration. We modified the classical Derjaguin expression to include the effect of nanoscale hydrodynamics boundary conditions for the accurate prediction of diffusio-osmosis characteristics. Overall, our results provide the clear guidance for controlling fluids flow and manipulating motion of colloids under tunable solute concentrations.

Beneficial effects of vitamin C and vitamin E on reserpine-induced oral dyskinesia in rats: Critical role of striatal catalase activity

2005 ◽  
Vol 48 (7) ◽  
pp. 993-1001 ◽  
Author(s):  
Rulian Ricardo Faria ◽  
Vanessa Costhek Abílio ◽  
Christian Grassl ◽  
Cibele Cristina Chinen ◽  
Luciana Takahashi Ribeiro Negrão ◽  
...  
Keyword(s):  
Vitamin E ◽  
Vitamin C ◽  
Catalase Activity ◽  
Critical Role ◽  
Beneficial Effects ◽  
Oral Dyskinesia

scholarly journals UAE-HPLC-UV: New Contribution for Fast Determination of Total Isothiocyanates in Brassicaceae Vegetables

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Cecilia M. Fusari ◽  
Daniela A. Locatelli ◽  
Jorgelina C. Altamirano ◽  
Alejandra B. Camargo
Keyword(s):  
Hydrolysis Product ◽  
Critical Factor ◽  
Analytical Performance ◽  
Extraction Technique ◽  
Solvent Ratio ◽  
Ultrasound Assisted Extraction ◽  
Analytical Methodology ◽  
Beneficial Effects ◽  
Homogenization Time ◽  
Assisted Extraction

Total isothiocyanates content (ITC) is considered a good indicator of bioactive compounds responsible for beneficial effects related to Brassicaceae vegetables.Analytical performance is a critical factor for routine analysis in plant tissues. The extraction technique for isolating phytochemicals from Brassicaceae vegetables is currently the bottleneck of the methodology. The aim of this work was to optimize this step in the analytical process. Fast and less expensive alternative, based on ultrasound-assisted extraction technique (UAE) for direct extraction of GLS into an aqueous phase and further analysis of the hydrolysis product, was optimized. Full factorial (2k) design followed by Central Composite Design (CCD) was used to obtain the optimum extraction conditions. Selected conditions were homogenization time (9 min); ultrasound bath time (5 min); and sample-to-solvent ratio (1 : 5 w/v mg mL−1). The proposed analytical methodology exhibits satisfactory analytical performance in terms of linearity, precision (RSD < 2.4%), and limits of detection (26 nmol g−1 w.w.). The new analytical methodology was applied to cauliflower, cabbage, watercress, and broccoli samples with recoveries higher than 86%. The UAE extraction technique was showed to be efficient for real samples analysis leading to sensible, selective, and reproducible methodology for ITC analysis.

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