Reproductive traits and mandibular gland pheromone of anarchistic honey bee workers Apis mellifera occurring in China

International audienceAbstractIn honey bee colonies, workers, in particular of “anarchistic” lineages, can activate their ovaries and lay eggs, even in the presence of the queen. We identified three queenright colonies showing typical signs of worker reproduction. To characterize this new lineage, we extracted the mandibular gland and analyzed it using gas chromatography. The total amounts of the five main components of the mandibular gland, namely methyl p-hydroxyben-zoate (HOB), 9-oxo-2(E)-decenoic acid (9-ODA), (S)-9-hydroxy-(E)-2-decenoic acid (9-HDA), 10-HDA, and 10-hydroxyde-canoic acid (10-HDAA) were significantly higher in the mandibular gland profiles of workers with activated ovaries (AWs, 8.88 ± 1.71 μg) compared to workers with inactivated ovaries (IAWs, 4.00 ± 2.09 μg). Furthermore, the chemical profiles of IAWs were dominated by the “worker substances” 10-HDA (34.64 ± 8.19 %) and its precursor 10-HDAA (22.88 ± 4.95 %), while the chemical profiles in AWs were dominated by the precursor of the queen substance 9-HDA (40.04 ± 7.55 %). The ratios of two precursor substances 10-HDAA/9-HDA of IAWs were more worker like (>1.0) whereas AWs were more queen like (≤1.0). These results suggest that the mandibular pheromones of anarchistic workers resemble a more queen-like reproductive active profile and that these workers may represent a reversion to a more basal reproductive phenotype

Copper-based charge transfer multiferroics with a d9d^9 configuration

Multiferroics are materials with a coexistence of magnetic and ferroelectric order allowing the manipulation of magnetism by applications of an electric field through magnetoelectric coupling effects. Here we propose an idea to design a class of multiferroics with a $d^9$ configuration using the magnetic order in copper-oxygen layers appearing in copper oxide high-temperature superconductors by inducing ferroelectricity. Copper-based charge transfer multiferroics SnCuO2 and PbCuO2 having the inversion symmetry breaking $P4mm$ polar space group are predicted to be such materials. The active inner s electrons in Sn and Pb hybridize with O $2p$ states leading the buckling in copper-oxygen layers and thus induces ferroelectricity, which is known as the lone pair mechanism. As a result of the $d^9$ configuration, SnCuO2 and PbCuO2 are charge transfer insulators with the antiferromagnetic ground state of the moment on Cu retaining some strongly correlated physical properties of parent compounds of copper oxide high-temperature superconductors. Our work reveals the possibility of designing multiferroics based on copper oxide high-temperature superconductors.Comment: 18 pages, 5 figures, 1 tabl

Elemental topological ferroelectrics and polar metals of few-layer materials

Ferroelectricity can exist in elemental phases as a result of charge transfers between atoms occupying inequivalent Wyckoff positions. We investigate the emergence of ferroelectricity in two-dimensional elemental materials with buckled honeycomb lattices. Various multi-bilayer structures hosting ferroelectricity are designed by stacking-engineering. Ferroelectric materials candidates formed by group IV and V elements are predicted theoretically. Ultrathin Bi films show layer-stacking-dependent physical properties of ferroelectricity, topology, and metallicity. The two-bilayer Bi film with a polar stacking sequence is found to be an elemental topological ferroelectric material. Three and four bilayers Bi films with polar structures are ferroelectric-like elemental polar metals with topological nontrivial edge states. For Ge and Sn, trivial elemental polar metals are predicted. Our work reveals the possibility of design two-dimensional elemental topological ferroelectrics and polar metals by stacking-engineering.Comment: 18 pages, 6 figure

Conductance of a quantum point contact in the presence of spin-orbit interaction

A recursive Green's function technique is developed to calculate the spin-dependent conductance in mesoscopic structures. Using this technique, we study the spin-dependent electronic transport of quantum point contacts in the presence of the Rashba spin-orbit interaction. We observed that some oscillations in the `quantized' conductance are induced by the spin-orbit interaction, and indicated that the oscillations may stem from the spin-orbit coupling associated multiple reflections. It is also indicated that the 0.7 structure of the conductance observed in mesoscopic experiments would not stem from the spin-orbit interaction.Comment: 8 page

PO-188 Effects of Tai-Chi exercise on blood lipids, inflammatory factors and baPWV of middle-aged and elderly people

Objective To investigate the interventional effects of 12 months Tai-Chi exercise on blood lipids, inflammatory factors and the interventional mechanism of exercise in arteriosclerosis of middle-aged and elderly people Methods 30 in middle-aged and elderly people with average age of 63.50±2.91 joined 12 months taijiquan exercise that conducted 60 minutes ecth time, six times per week. Left brachial-ankle pulse wave velocity (L-baPWV), right brachial-ankle pulse wave velocity(R-baPWV) , left ankle brachial index (L-ABI), right ankle brachial index(R-ABI), serum triglyceride(TG), total cholesterol(TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), interleukin 6 (IL-6) and hypersensitive c-reactive protein (hs-CRP) were detected at 3 time points including before exercise programme, by the end of exercise for 6th and 12th month. Results ①Compared with pre-exercise, the R-baPWV and R-ABI of the elderly people were decreased at the end of the 6th month, and the L-baPWV, R-baPWV, R-ABI and L-ABI were decreased significantly at the end of the 12th month. ②Compared with pre-exercise, TC and LDL-c were declined markedly (P<0.01) at the end of the 6th and the 12th month, and there was no difference of the level of TG and LDL-c between pre-exercise and post-exercise.③Compared with before exercise, the subjects had significantly decreased IL-6 at the end of  6th months of exercise (P < 0.01), and the decrease of hs-CRP was not obvious. At the end of 12 th months, IL-6 and hs-CRP decreased significantly (P < 0.01). ④According to the correlation analysis, baPWV were positively correlated with TC, IL-6 and hs-CRP. Conclusions 12 months of exercise intervention can effectively reduce the elderly baPWV and ABI level, improve the blood pressure, blood lipid and body inflammation levels, thus to prevent the happening of the atherosclerosis development plays an important role