Space-Time-Energy Equivalence

The equivalence of space–time and energy are the principle that everything that has space and time has an equivalent amount of energy, and vice versa. It is presented here as an axiom that has become widespread in physics and astrophysics.

A cell engineering approach to enzyme-based fed-batch fermentation

Background A fundamental problem associated with E. coli fermentations is the difficulty in achieving high cell densities in batch cultures, attributed in large part to the production and accumulation of acetate through a phenomenon known as overflow metabolism when supplying enough glucose for the cell density desired. Although a fed-batch configuration is the standard method for reducing such issues, traditional fed-batch systems require components which become problematic when applying them at smaller scale. One alternative has been the development of a system whereby the enzymatic degradation of starch is used to release glucose at a controlled rate. However, to date, amylolytic enzymes have only been applied to the culture exogenously, whereas our goal is to design and construct a self-secreting amylolytic chassis capable of self-regulated enzyme-based fed-batch fermentation. Results A putative glucoamylase from C. violaceum has been cloned and expressed in E. coli BL21(DE3) and W3110, which exhibits significant glucose releasing amylolytic activity. Extracellular amylolytic activity was enhanced following a replacement of the enzymes native signal peptide with the DsbA signal sequence, contributing to a glucoamylase secreting strain capable of utilising starch as a sole carbon source in defined media. Introduction of PcstA, a glucose sensitive K12 compatible promoter, and the incorporation of this alongside C. violaceum glucoamylase in E. coli W3110, gave rise to increased cell densities in cultures grown on starch (OD600 ∼ 30) compared to those grown on an equivalent amount of glucose (OD600 ∼ 15). Lastly, a novel self-secreting enzyme-based fed-batch fermentation system was demonstrated via the simultaneous expression of the C. violaceum glucoamylase and a recombinant protein of interest (eGFP), resulting in a fourfold increase in yield when grown in media containing starch compared with the glucose equivalent. Conclusions This study has developed, through the secretion of a previously uncharacterised bacterial glucoamylase, a novel amylolytic E. coli strain capable of direct starch to glucose conversion. The ability of this strain to achieve increased cell densities as well as an associated increase in recombinant protein yield when grown on starch compared with an equivalent amount of glucose, demonstrates for the first time a cell engineering approach to enzyme-based fed-batch fermentation.

Influence of High-Calcium Ash Composition on the Composite Binders’ Properties

The paper presents the studies’ results of chemical composition, structure, and physico-mechanical properties of high-calcium ashes from the Kansk-Achinsk coals (2017-2019 selection). It was found that ash has a complex poly-mineral composition and contains hydraulically active minerals and oxides of СаОfr, β-C2S, CA, C3A, C4AF, C2F, CaSO4. According to the content of CaOfr, MgO does not meet standards’ requirements. The uniformity of the volume change is maintained by the composition with 50% of cement. The structure and hardening kinetics of ash and ash-cement stone compositions, obtained from the test of normal density, were analyzed. It was established that the hardening of compositions with ash from the Kansk-Achinsk coals was largely influenced by ash minerals. An equivalent amount of cement in composite binders cannot be replaced. In order to obtain a positive effect, compositions with ash instead cement of no more than 30% and a part of fine aggregate, without exceeding the ratio of ash: cement = 1: 1, should be used.

The Impact of Policy Shift from In-kind Transfers to Direct Cash Transfers on Paddy Production: Evidence from Mahaweli H System in Sri Lanka

In 2016, the Sri Lankan government introduced a policy change related to fertilizer subsidy by converting the in-kind transfer into a direct cash transfer. This research article analyses the consequences of this policy change on the paddy production from economics perspective. The analysis uses national-level data from 1961 to 2013 and farm-level data collected in 2016. Macro-level findings manifest that the use of fertilizer significantly increases the paddy production in Sri Lanka. It was also identified that the cash amount granted under the direct cash transfer policy is not equivalent to the in-kind transfer programme. As a result, paddy production is expected to decline under the direct cash transfer programme when compared to the material subsidy scheme. However, this is against the preference of economists on direct cash transfers over in-kind transfers. The findings reveal that direct cash transfers increase the paddy production under two conditions: (a) when rational farmers effectively utilize the cash grants to optimize their production inputs; and (b) an equivalent amount of in-kind transfer is provided as direct cash transfer. Hence, direct cash transfers are not always better than in-kind transfers; it is better when in-kind transfer is compensated with an equivalent amount of cash transfer. JEL: A1, B1, B2, C1, C5, D6, N5

Charitable Contribution Matching and Effort-Elicitation

We examine the effect of a charitable contribution matching (CCM) program on employee effort. In CCM programs, employers commit to match employees' donations to charity. We expect CCM to activate a norm of other-regarding behavior, inducing employees to increase effort to benefit their employer. Experimental results robustly support our expectation. We find that CCM increases effort under both fixed-wage and performance-based incentive contracts. Further, our results suggest CCM is more effective at eliciting effort than alternative uses of firm capital. Specifically, CCM is more effective at eliciting effort than the firm allocating an equivalent amount of capital to either direct firm charitable giving or increased performance-based pay. Our study suggests that CCM has efficient and robust effort-elicitation benefits that increase its value as a compensation tool incremental to any initial employee selection benefits from CCM and any effort benefits from firms' direct charitable giving.

Comparative studies of dual bronchodilation in COPD

Dual bronchodilation therapy is becoming the cornerstone for the treatment of COPD because the clinical benefits of LABA/LAMA fixed-dose combinations (FDCs) are now extensively established. Therefore, it not surprising that a number of LAMA/LABA combinations in a single inhaler have now been approved for clinical use as treatments for patients with COPD. Regrettably, very few head-to-head studies between all of the available LABA/LAMA FDCs have been carried out. This makes choosing the most appropriate FDC difficult. Comparative effectiveness research that also uses conventional meta-analyses to compare different care strategies can help generate useful information. A bidimensional comparative analysis across LAMA/LABA FDCs has suggested constant superiority for tiotropium/olodaterol. However, considering that there is not an equivalent amount of evidence on efficacy outcomes for all LAMA/LABA FDCs, a proper comparison between the different LAMA/LABA FDCs cannot be made yet, and the information available is still rather inconsistent.

Vanillin based polymers: V. Poly(hydrovanilloin–urethane)

Renewable resources based hydrovanilloin [1,2- bis(4-hydroxy-3-methoxyphenyl)-1,2-ethanediol] was synthesized in 86% yield by electrochemical dimerization of vanillin in aqueous NaOH. This symmetrical bis-phenol monomer was then used for the preparation of urethane polymers by two different methods. In the first method a 1:2 mole ratio mixture of hydrovanilloin and diisocyanate was polymerized in DMF using 1,4-diazabicyclo[2,2,2]octane as the catalyst at 60°C, for 1 h to give poly(hydrovanilloin–urethane)s. In the second method diisocyanates were first reacted with polyethylene glycol-400 to give pre-polymers. Then prepolymers were reacted with equivalent amount of hydrovanilloin at 60°C for 4 days to produce poly(hydrovanilloin-ethylene glycol-urethane)s. The first method resulted hard poly(hydrovanilloin–urethane)s showing Tg values in the range of 121–172°C. The second method yielded softer poly(hydrovanilloin-ethylene glycol-urethane)s and these polymers failed to show distinct glass transition temperatures in the DSC analysis. However, poly(hydrovanilloin-ethylene glycol-urethane)s showed better thermal stabilities than polymers without polyethylene glycol units.

Testing a Theoretical Assumption of a Learning-Trajectories Approach in Teaching Length Measurement to Kindergartners

We tested a specific theoretical assumption of a learning trajectories (LTs) approach to curriculum and teaching in the domain of early length measurement. Participating kindergartners (n = 189) were assigned to one of three conditions: LT, reverse-order (REV), or business-as-usual (BAU). LT and REV students received one-on-one instruction using the same activities from a length LT, while the REV condition reversed the LT order. At posttest, LT and REV children exhibited significantly greater learning relative to BAU peers. But importantly, LT children outperformed their REV peers. We conclude that instruction following LTs (i.e., providing instruction just beyond a child’s present level of thinking, progressing through the levels in order as the child advances) may promote more learning than an equivalent amount of instruction using the same activities but that are not theoretically sequenced.

A Combined Experimental and Theoretical Study on a Single, Unsupported Oxo-Bridged Mn(III,III) Dimer Coordinated to Two Iminobenzosemiquinone -Radical Anions

Ligand H2LAP was comprised of a non-innocent 2-aminophenol unit and an innocent bis(pyridin-2-ylmethyl)amine unit. The ligand, upon reaction with an equivalent amount of Mn(ClO4)2•6H2O in the presence of Et3N under...

Physicochemical properties of new S-derivatives of 5-(5-bromofuran-2-yl)-4-methyl-1,2,4-triazol-3-thiols

The alkylation of 5-(5-bromofuran-2-yl)-4-methyl-1,2,4-triazole-3-thiol with bromoalkanes was carried out. Synthesis was accomplished by addition of equivalent amounts of bromoalkanes (bromomethane, bromoethane, bromobutane–bromodecane) to 5-(5-bromofuran-2-yl)-4-methyl-1,2,4-triazole-3-thiol in a methanol medium in the presence of an equivalent amount of sodium hydroxide. Compounds were obtained with a high yield. The next step was to investigate the reaction of 5-(5-bromofuran-2-yl)-4-methyl-1,2,4-triazole-3-thiol with some other halogen-containing compounds, the mechanism of the reaction of which also relates to nucleophilic substitution. As halogen-containing compounds, we used bromoacetone, bromoacetophenone, chloroacetic acid and chloroacetamide. Under these conditions, a series of new compounds were synthesized. Structure of compounds was confirmed by 1H NMR spectroscopy and elemental analysis. The antibacterial activity of the synthesized compounds towards cryogenic strains of Enterobacteriaceae, Pseudomonadaceae, Staphylococcaceae, Bacillaceae, Listeriaceae, Corynebacteriaceae and Saccharomycetaceae families in vitro was also investigated. According to the data obtained, one can conclude that the investigated compounds can compete with kanamycin, a natural broad-spectrum antibiotic from the second generation of aminoglycosides, whose range of action includes gram-positive and gram-negative microorganisms. The compounds involved may be recommended for further investigation of their action against multi-resistant strains of microorganisms.