Leaf vegetables for use in integrated hydroponics and aquaculture systems: Effects of root flooding on growth, mineral composition and nutrient uptake

In recirculating aquaculture and hydroponics systems, the waste products from fish production are used to produce vegetables or other crops of economic value, and the water is recirculated to the fish tanks. We studied growth, productivity and nutrient uptake of four leaf vegetable species (Lactuca sativa, Ipomoea aquatica, Brassica rapa var. chinensis and Brassica rapa var. parachinensis) in a controlled growth experiment with three root flooding treatments (drained, half-flooded and flooded) toassess their preferred hydroponic growth requirements, biomass production and nutrient removal capacities. Growth of the two Brassica varieties was clearly best at drained root conditions, while L. sativa and I. aquatica grew best with half-flooded and flooded roots. I. aquatica took up 3 times more N, P and K per plant than L. sativa, and 4 to 6 times more than the two Brassica varieties. At a plant density of 30 plants/m2, I. aquatica produced 146 g DW/m2 aboveground biomass during a 30-day cultivation period containing 2.8, 0.9 and 6.8 g/m2 of N, P and K, respectively. L. sativa produced 115 g DW/m2 of aboveground DW during a 60-day cultivation period, containing 2.2, 0.6 and 4.6 g/m2 of N, P and K, respectively. The two Brassica varieties produced much less aerial biomass (50-54 g DW/m2 during a 60-day period). Both I. aquatica and L. sativa are promising species to be included in integrated hydroponic and aquaculture facilities, with I. aquatica showing the most promise because of its higher growth and nutrient uptake capacity

On the Convergence to a Global Solution of Shuffling-Type Gradient Algorithms

Stochastic gradient descent (SGD) algorithm is the method of choice in many machine learning tasks thanks to its scalability and efficiency in dealing with large-scale problems. In this paper, we focus on the shuffling version of SGD which matches the mainstream practical heuristics. We show the convergence to a global solution of shuffling SGD for a class of non-convex functions under over-parameterized settings. Our analysis employs more relaxed non-convex assumptions than previous literature. Nevertheless, we maintain the desired computational complexity as shuffling SGD has achieved in the general convex setting.Comment: The 37th Conference on Neural Information Processing Systems (NeurIPS 2023

Co-doping red-emitting Sr2Si5N8:Eu2+ into yellow-emitting phosphor-packaging for enhancing the optical properties of the 8500 K remote-phosphor packaging wleds

In the last decades, WLEDs attract more and more consideration in both academic and industrial purposes because of its advantages such as fast response time, environment friendliness, small size, long lifetime, and high efficiency. In this research, by doping the red-emitting Sr2Si5N8:Eu2+ phosphor particles into yellow-emitting YAG:Ce phosphor-packaging, a new recommendation for enhancing the optical properties (color uniformity, color rendering index, and lumen output) of the 8500 K remote-phosphor packaging WLEDs is presented, investigated, and demonstrated. By using Mat Lab and Light Tools software based on Mie Theory, the obtained results show that the optical properties of the 8500 K remote-phosphor packaging WLEDs significantly depended on Sr2Si5N8:Eu2+ concentration. The results have provided a potential practical recommendation for manufacturing remote-phosphor W-LEDs.Web of Science1341034102

Kinetics and Mechanism of Oxidation of N-acetyl-d-penicillamine in Acidified Iodate and Aqueous Iodine

The oxidation of the biologically-active thiol, N-acetyl-d-penicillamine (NDPen) by acidified iodate and aqueous iodine has been studied. The stoichiometry of the reaction is 1:1 in which the thiol (RSH) is oxidized to its sulfonic acid (RSO3H) without cleavage of the C-S bond. In excess acidified iodate the reaction displayed a short induction period, followed by formation of aqueous iodine. Overall stoichiometry in excess iodate was 6:5: 6 IO3 –+5RSH+6H+→5 RSO3H+3I2(aq)+3H2O. The direct reaction of aqueous iodine and was relatively fast, over within 100 ms and had a stoichiometry of 1:3: 3 I2(aq) + RSH+3H2O →RSO3H+6 I– + 6 H+. The reaction is essentially diffusion-controlled and our stopped-flow with a mixing time limitation of 1.00 ms could only catch the reaction of the last iodine molecule. This reaction is, however, strongly inhibited by the product of reaction, I– . This is due to the formation of the relatively inert triiodide anion: I2(aq)+I–→I3 –. Mass spectrometry results showed that the reaction proceeds through the sulfinic acid with negligible stabilization of the sulfenic acid. In excess of reductant, the dimeric species is the favoured product due to a rapid condensation-type reaction between the electrophilic unstable sulfenic acid and unreacted thiol.Keywords: Biological thiols, bioactivation, oxidations, oxyhalogen chemistry

Synthesis and NMR-Characterization of Three Quinamide-Based Disaccharide Mimetics with Unusual Cyclohexane twist-Conformation

The synthesis of amide-linked disaccharide mimetics has been explored starting with carbohydrate-based amines and a protected quinic acid lactone. Benzyl-2-amino-4,6-Obenzylidene-2-deoxy-α/β-D-glucopyranose (12) and D-glucamine (14) were successfully coupled to give the corresponding quinamides (13 and 15), while the quinoylation of Oacetylated L-fucopyranosyl methylamine (7) failed. The latter was prepared from per-O-acetylL-fucopyranose via the improved multigram scale synthesis of the corresponding per-O-acetylL-fucopyranosyl cyanide (3). Compound 3 was subsequently hydrogenated to yield a mixture of compound 7 and the per-O-acetylated bis-(fucopyranosylmethyl) amine (5). The vicinal coupling constants in the NMR spectra of all quinamide products revealed considerable flexibility of the cyclohexane ring in solution and substantial contributions by twist-chair conformations

How swelling debts give rise to a new type of politics in Vietnam

Vietnam has seen fast-rising debts, both domestic and external, in recent years. This paperreviews the literature on credit market in Vietnam, providing an up-to-date take on the domesticlending and borrowing landscape. The study highlights the strong demand for credit in both therural and urban areas, the ubiquity of informal lenders, the recent popularity of consumer financecompanies, as well as the government’s attempts to rein in its swelling public debt. Given thehigh level of borrowing, which is fueled by consumerism and geopolitics, it is inevitable that theamount of debt will soon be higher than the saving of the borrowers. Unlike the conventional wisdom that creditors have more bargaining power over the borrowers, we suggest that—albeitlacking a quantitative estimation—when the debts pile up so high that the borrowers could not repay, the power dynamics may reverse. In this new politics of debt, the lenders fear to lose the money's worth and continue to lend and feed the insolvent debtors. The result is a toxic lending/borrowing market and profound lessons, from which the developing world could learn

Protein Delivery of an Artificial Transcription Factor Restores Widespread Ube3a Expression in an Angelman Syndrome Mouse Brain.

Angelman syndrome (AS) is a neurological genetic disorder caused by loss of expression of the maternal copy of UBE3A in the brain. Due to brain-specific genetic imprinting at this locus, the paternal UBE3A is silenced by a long antisense transcript. Inhibition of the antisense transcript could lead to unsilencing of paternal UBE3A, thus providing a therapeutic approach for AS. However, widespread delivery of gene regulators to the brain remains challenging. Here, we report an engineered zinc finger-based artificial transcription factor (ATF) that, when injected i.p. or s.c., crossed the blood-brain barrier and increased Ube3a expression in the brain of an adult mouse model of AS. The factor displayed widespread distribution throughout the brain. Immunohistochemistry of both the hippocampus and cerebellum revealed an increase in Ube3a upon treatment. An ATF containing an alternative DNA-binding domain did not activate Ube3a. We believe this to be the first report of an injectable engineered zinc finger protein that can cause widespread activation of an endogenous gene in the brain. These observations have important implications for the study and treatment of AS and other neurological disorders

Diversity and Activity of Microbial Extracellular Peptidases in Soil

Soil nitrogen exists largely as organic matter, including plant liter, dead animal matter, and microbial necromass. About 90% of soil organic nitrogen is proteinaceous material that is too large for plants and microorganisms to assimilate directly. Protein depolymerization therefore plays a critical role in mobilizing this organic source of nitrogen, producing lower molecular weight molecules that are bioavailable for both microorganisms and plants. The decomposition of proteins in soils serves as the rate-limiting step of the nitrogen cycle. The ability of microorganisms to access and break down proteinaceous material depends largely on their production of extracellular peptidases, but it involves a trade-off with the energetic cost of producing and secreting these enzymes into the environment, including the risk that other microorganisms can compete with the peptidase-producing organisms for the products released through depolymerization. Consequently, in order to optimize this energy investment, there might be a tight connection between soil environmental conditions and microbial proteolytic activity. Despite its ecological importance, there is a lack of understanding about the diversity of these extracellular peptidases and their activity as an important factor influencing the protein degradability in soils. In this dissertation, I first assessed the genetic potential for microorganisms to produce extracellular enzymes, and second, I developed and applied a novel approach to measure the activities of different classes of peptidases in soil. In my first two chapters, I evaluated the abundance and diversity of microbial extracellular peptidases, their evolutionary conservation, and distribution as a function of environmental habitat and lifestyle. Chapter 2 focuses on the secreted peptidases of prokaryotes (Archaea, Bacteria); chapter 3 focuses on Fungi, the dominant soil eukaryote. In both chapters, I analyzed secreted peptidases across microbial lineages using their genomic information and corresponding annotated protein sequences assembled from several databases, including MEROPS, Silva, JGI Genome Portal, and MycoCosm. Peptidase gene sequences of 147 archaeal, 2,191 bacterial and 612 fungal genomes were screened for secretion signals, resulting in 55,072 prokaryotic and 31,668 eukaryotic genes coding for secreted peptidases. I found that Archaea, Bacteria, and Fungi possess unique complements of secreted peptidases and there are differences in the number of secreted peptidases per genome, indicating potential differential abilities for organic nitrogen acquisition. The majority of secreted peptidase families not only follow the phylogenetic evolutionary distribution, but also segregate based on the microbial lifestyles and microbial habitats. This suggests that microorganisms optimize their secreted peptidases to match their surrounding environments. In Chapter 4, I incorporated the use of selective inhibitors to block the activity of different classes of peptidases. I designed a protocol with these peptidase inhibitors to use directly in natural soils. I validated and optimized this protocol with pure enzymes and peptidase-supplemented soils. This research revealed that the profile of extracellular peptidase activities belonging to different catalytic types varies among soils and correlates with both soil chemical and microbial properties. This is in line with our assumption that soil microorganisms respond to their environmental conditions by investing in peptidases that can optimize their activity. Collectively, this work provides a comprehensive and foundational understanding about the contribution of different catalytic types of microbial extracellular peptidases to organic nitrogen turnover in soils