Why not be a queen? Regioselectivity in mandibular secretions of honeybee castes

Both female castes of the honeybee (Apis mellifera L.) synthesize hydroxylated 2(E)-decenoic acids in their mandibular glands. Queens produce 9-hydroxy-2(E)-decenoic acid as part of their primer pheromone, while workers produce the regioisomeric 10-hydroxy acid, probably as a larval food source and an antiseptic secretion. Both workers and queens are biosynthetically competent to produce the other caste's dominant hydroxylated compound, as both isomers can be detected in queens and workers. We investigated the source of the caste-determined regioselectivity of hydroxy acid biosynthesis by investigating the production and interconversion of these compounds in isolated worker honeybee mandibular glands with specifically deuterated precursors. Gas chromatographic-mass spectroscopic identification of the labeled product indicates that octadecanoic acid is converted into 10-hydroxy-2(E)-decenoic acid with higher efficiency than either hexadecanoic or decanoic acids. 10-Hydroxydecanoic acid is readily converted into 10-hydroxy-2(E)-decenoic acid as expected in the -oxidation process. The saturated and unsaturated 10-hydroxy acids are oxidized to the corresponding ten carbon diacids.     

Why does the CIELAB a* axis point toward magenta instead of red?

Red is a basic color. The work of Kay and Berlin on the evolution of color names in languages shows that, after white and black, red is the most basic of color terms. Red plays a key part in Hering's color opponent theory, and is one of the elementary colors in both the Munsell Color system and in the Natural Colour System (NCS). The CIELAB color system has an axis which is sometimes referred to as the red-green axis. But unique red is about 25° degrees counterclockwise from the positive a* axis. This article answers the question of why this is.     

Why Are Biological Systems Homochiral?

Self-assembling and self-organizable dendrons, dendrimers, and dendronized polymers produce chiral supramolecular architectures that have been developed as biological mimics. Here we review our work on the self-assembly of homochiral, heterochiral, and racemic dendritic dipeptides, and address one of the most fundamental questions of biological systems: Why are biological systems homochiral and not heterochiral or racemic and, if they were heterochiral or racemic, how would they look and function by comparison with contemporary homochiral biological systems?     

Why Are We Creating Less Garbage?

Something odd happened to our garbage a couple decades ago. We started creating less of it. According to a new study by researchers at the Earth Engineering Center at City College of New York, sometime around the late 1990s we began to see a decrease in the rate at which we generate waste compared to economic growth. Typically, as gross domestic product (GDP) increases, the amount of trash increases along with it, at about the same rate. The authors note that both GDP and waste generation tracked each other from 1960 on, as expected—until the late 1990s. Then, as GDP continued to climb, waste generation began to climb more slowly. We were getting richer, but we were creating less waste     

Why Rhodium in Automotive Three-Way Catalysts?

The catalytic treatment of motor vehicle exhaust gas has been a feature of all passenger cars in the USA since the 1975 model year. It has since been adopted in all the developed countries as the principal means of con-trolling the emissions from vehicles powered by Otto-cycle internal com-bustion engines. These include passenger cars, light trucks, and heavy-duty trucks. Catalysts have been developed for motorcycles and even smaller power plants. The so-called three-way catalyst (TWC) has been in use since the 1979 model year. The name reflects the simultaneous treatment by this catalyst of the two reducing pollutants, carbon monoxide and uncombusted hydrocarbons, and the oxidizing pollutant, oxides of nitrogen.     

Why Is Longevity Still a Scientific Mystery? Sirtuins—Past,Present and Future

The sirtuin system consists of seven highly conserved regulatory enzymes responsible for metabolism, antioxidant protection, and cell cycle regulation. The great interest in sirtuins is associated with the potential impact on life extension. This article summarizes the latest research on the activity of sirtuins and their role in the aging process. The effects of compounds that modulate the activity of sirtuins were discussed, and in numerous studies, their effectiveness was demonstrated. Attention was paid to the role of a caloric restriction and the risks associated with the influence of careless sirtuin modulation on the organism. It has been shown that low modulators’ bioavailability/retention time is a crucial problem for optimal regulation of the studied pathways. Therefore, a detailed understanding of the modulator structure and potential reactivity with sirtuins in silico studies should precede in vitro and in vivo experiments. The latest achievements in nanobiotechnology make it possible to create promising molecules, but many of them remain in the sphere of plans and concepts. It seems that solving the mystery of longevity will have to wait for new scientific discoveries.