Towards a feasible income equality

To reach perfect income equality, factors that determine individual income, such as intelligence, inherited wealth, personalities, and social skills, should be identical for everyone. That is an infeasible ideal. Chae Un Kim and Ji-Won Park propose a more feasible and realistic concept of income equality that could be incorporated in the Gini coefficient, the most widely used measure of inequality, guaranteeing the maximisation of overall social welfare without hampering overall economic efficacy

Structure and mechanism of copper-carbonic anhydrase II: A nitrite reductase

Nitric oxide (NO) promotes vasodilation through the activation of guanylate cyclase, resulting in the relaxation of the smooth muscle vasculature and a subsequent decrease in blood pressure. Therefore, its regulation is of interest for the treatment and prevention of heart disease. An example is pulmonary hypertension which is treated by targeting this NO/vasodilation pathway. In bacteria, plants and fungi, nitrite (NO2 -) is utilized as a source of NO through enzymes known as nitrite reductases. These enzymes reduce NO2 - to NO through a catalytic metal ion, often copper. Recently, several studies have shown nitrite reductase activity of mammalian carbonic anhydrase II (CAII), yet the molecular basis for this activity is unknown. Here we report the crystal structure of copper-bound human CAII (Cu-CAII) in complex with NO2 - at 1.2 ?? resolution. The structure exhibits Type 1 (T-1) and 2 (T-2) copper centers, analogous to bacterial nitrite reductases, both required for catalysis. The copper-substituted CAII active site is penta-coordinated with a 'side-on' bound NO2 -, resembling a T-2 center. At the N terminus, several residues that are normally disordered form a porphyrin ring-like configuration surrounding a second copper, acting as a T-1 center. A structural comparison with both apo-(without metal) and zinc-bound CAII (Zn-CAII) provides a mechanistic picture of how, in the presence of copper, CAII, with minimal conformational changes, can function as a nitrite reductase. ?? 2020 Andring et al

Laboratory Astrophysics Using Intense Ion and Photon Beams Generated by Large-Scale Accelerator Facilities in Korea

Several large-scale accelerator facilities are operational or under construction in Korea, such as the Korea Multi-purpose Accelerator Complex (KOMAC), the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL), and the Rare Isotope Science Project (RISP). These accelerator projects open up new opportunities in basic science researches in Korea, and provide excellent platforms particularly for laboratory astrophysics..

A Study on Performance Design Using a Sprinkler System for Fire-Spread Prevention of a Building Exterior

A glass exterior material is normally used in buildings, but it also comes with a disadvantage—it is easily damaged by fire. If the glass exterior material is damaged, a fire can rapidly propagate inside the building space, leading to a lot of damage from the flame transfer to the other space. In this study, the performance of a sprinkler for flame propagation prevention was evaluated during an experiment with an actual proof fire. The study found that where the sprinkler is installed with the glass exterior material, the temperature does not exceed 60°C until the end of the test due to the effect of the water curtain. In the glass exterior material where the sprinkler is not installed, the temperature rapidly increased just after starting the experiment, and caused damage 21 minutes and 30 seconds after starting the test

Laboratory Astrophysics Using Intense Ion and Photon Beams Generated by Large-Scale Accelerator Facilities in Korea

Several large-scale accelerator facilities are operational or under construction in Korea, such as the Korea Multi-purpose Accelerator Complex (KOMAC), the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL), and the Rare Isotope Science Project (RISP). These accelerator projects open up new opportunities in basic science researches in Korea, and provide excellent platforms particularly for laboratory astrophysics..

The Study on Fire Safety by a Real-Scale Combustion Experiment of Composite Material

In this study, a real-scale combustion experiment was carried out for a Styrofoam and glass wool sandwich panel to figure out the fire safety for the composite material used for a building. In the experiment, a heat release rate of a sandwich panel was measured by the ISO 9705 fire test method. Research has also tested and compared temperature change in the Large Scale Calorimeter (LSC) experiment equipment to evaluate the structural safety of the structure body. As a result of the experiment, the structural body with the Styrofoam sandwich panel collapsed which was caused by propagation, and in case of the glass wool sandwich panel, the combustion did no propagate inside. Since the composite material experiences various types of fire hazards depending on the combustion characteristics of the core material, the exact combustion characteristic should be expected by the full-scale combustion experiment

Ethylene Inhibitors Enhance Shoot Organogenesis of Gloxinia ( Sinningia speciosa

Shoot organogenesis and plant regeneration in Sinningia speciosa were improved using ethylene inhibitors. The leaf explants were cultured on initial shoot regeneration media (MS media with BAP at 2 mg/L + NAA at 0.1 mg/L) supplemented with different concentrations of aminoethoxyvinylglycine (AVG), cobalt chloride (CoCl2), and silver thiosulphate (STS). The addition of AVG, CoCl2, and STS significantly improved the regeneration frequency giving higher shoots per explant and longer shoot length. The highest shoot growth was found when STS at 5 mg/L was incorporated with generation medium, performing highest regeneration frequency with highest number of shoots. This treatment (STS at 5 mg/L) produced 40% more shoots per explant compared to control followed by STS at 10 mg/L with increasing 37% more shoots compared to control. In the cases of AVG and CoCl2 the highest shoot number per explant was found at 1 mg/L. Treated with AVG and CoCl2 at 1 mg/L increased shoot number by 16 and 12%, respectively, compared to control. Ethylene inhibitors could be used as a possible micropropagation and plant transformation protocol in S. speciosa for plant regenerations

Active-site solvent replenishment observed during human carbonic anhydrase II catalysis

Human carbonic anhydrase II (hCA II) is a zinc metalloenzyme that catalyzes the reversible hydration/dehydration of CO2/HCO3-. Although hCA II has been extensively studied to investigate the proton-transfer process that occurs in the active site, its underlying mechanism is still not fully understood. Here, ultrahigh-resolution crystallographic structures of hCA II cryocooled under CO2 pressures of 7.0 and 2.5 atm are presented. The structures reveal new intermediate solvent states of hCA II that provide crystallographic snapshots during the restoration of the proton-transfer water network in the active site. Specifically, a new intermediate water (W IHTC/SUBTAG'FORTITLEHTC_RETAIN) is observed next to the previously observed intermediate water W-I,W- and they are both stabilized by the five water molecules at the entrance to the active site (the entrance conduit). Based on these structures, a water network-restructuring mechanism is proposed, which takes place at the active site after the nucleophilic attack of OH- on CO2. This mechanism explains how the zinc-bound water (W-Zn) and W-1 are replenished, which are directly responsible for the reconnection of the His64-mediated proton-transfer water network. This study provides the first 'physical' glimpse of how a water reservoir flows into the hCA II active site during its catalytic activity

The Boltzmann fair division for distributive justice

Fair division is a significant, long-standing problem and is closely related to social and economic justice. The conventional division methods such as cut-and-choose are hardly applicable to real-world problems because of their complexity and unrealistic assumptions about human behaviors. Here we propose a fair division method from a completely different perspective, using the Boltzmann division. The mathematical model of the Boltzmann division was developed for both homogeneous and heterogeneous cake-cutting problems, and the realistic human factors (contributions, needs, and preferences) of the multiple participating players could be successfully integrated. The Boltzmann division was then optimized by maximizing the players' total utility. We show that the Boltzmann fair division is a division method favorable to the socially disadvantaged or underprivileged, and it is drastically simple yet highly versatile and can be easily fine-tuned to directly apply to a variety of social, economic, and political division problems

The Boltzmann fair division for distributive justice

Fair division is a significant, long-standing problem and is closely related to social and economic justice. The conventional division methods such as cut-and-choose are hardly applicable to real-world problems because of their complexity and unrealistic assumptions about human behaviors. Here we propose a fair division method from a completely different perspective, using the Boltzmann division. The mathematical model of the Boltzmann division was developed for both homogeneous and heterogeneous cake-cutting problems, and the realistic human factors (contributions, needs, and preferences) of the multiple participating players could be successfully integrated. The Boltzmann division was then optimized by maximizing the players' total utility. We show that the Boltzmann fair division is a division method favorable to the socially disadvantaged or underprivileged, and it is drastically simple yet highly versatile and can be easily fine-tuned to directly apply to a variety of social, economic, and political division problems