Geometric Phase Generated Optical Illusion

Abstract An optical illusion, such as “Rubin’s vase”, is caused by the information gathered by the eye, which is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source. Metasurfaces are metamaterials of reduced dimensionality which have opened up new avenues for flat optics. The recent advancement in spin-controlled metasurface holograms has attracted considerate attention, providing a new method to realize optical illusions. We propose and experimentally demonstrate a metasurface device to generate an optical illusion. The metasurface device is designed to display two asymmetrically distributed off-axis images of “Rubin faces” with high fidelity, high efficiency and broadband operation that are interchangeable by controlling the helicity of the incident light. Upon the illumination of a linearly polarized light beam, the optical illusion of a ‘vase’ is perceived. Our result provides an intuitive demonstration of the figure-ground distinction that our brains make during the visual perception. The alliance between geometric metasurface and the optical illusion opens a pathway for new applications related to encryption, optical patterning, and information processing

Limosilactobacillus balticus sp. nov., Limosilactobacillus agrestis sp. nov., Limosilactobacillus albertensis sp. nov., Limosilactobacillus rudii sp. nov. and Limosilactobacillus fastidiosus sp. nov., five novel Limosilactobacillus species isolated from the vertebrate gastrointestinal tract, and proposal of six subspecies of Limosilactobacillus reuteri adapted to the gastrointestinal tract of specific vertebrate hosts

Ten strains, BG-AF3-A(T), pH52_RY, WF-MT5-A(T), BG-MG3-A, Lr3000(T), RRLNB_1_1, STM3_1(T), STM2_1, WF-MO7-1(T) and WF-MA3-C, were isolated from intestinal or faecal samples of rodents, pheasant and primate. 16S rRNA gene analysis identified them as Limosilactobacillus reuteri. However, average nucleotide identity and digital DNA-DNA hybridization values based on whole genomes were below 95 and 70%, respectively, and thus below the threshold levels for bacterial species delineation. Based on genomic, chemotaxonomic and morphological analyses, we propose five novel species with the names Limosilactobacillus balticus sp. nov. (type strain BG-AF3-A(T)=DSM 110574(T)=LMG 31633(T)), Limosilactobacillus agrestis sp. nov. (type strain WF-MT5-A(T)=DSM 110569(T)=LMG 31629(T)), Limosilactobacillus albertensis sp. nov. (type strain Lr3000(T)=DSM 110573(T)=LMG 31632(T)), Limosilactobacillus rudii sp. nov. (type strain STM3_1(T)=DSM 110572(T)=LMG 31631(T)) and Limosilactobacillus fastidiosus sp. nov. (type strain WF-MO7-1(T)=DSM 110576(T)=LMG 31630(T)). Core genome phylogeny and experimental evidence of host adaptation of strains of L. reuteri further provide a strong rationale to consider a number of distinct lineages within this species as subspecies. Here we propose six subspecies of L. reuteri: L. reuteri subsp. kinnaridis subsp. nov. (type strain AP3(T)=DSM 110703(T)=LMG 31724(T)), L. reuteri subsp. porcinus subsp. nov. (type strain 3c6(T)=DSM 110571(T)=LMG 31635(T)), L. reuteri subsp. murium subsp. nov. (type strain lpuph1(T)=DSM 110570(T)=LMG 31634(T)), L. reuteri subsp. reuteri subsp. nov. (type strain F 275(T)=DSM 20016(T)=ATCC 23272(T)), L. reuteri subsp. suis subsp. nov. (type strain 1063(T)=ATCC 53608(T)=LMG 31752(T)) and L. reuteri subsp. rodentium subsp. nov. (type strain 100-23(T)=DSM 17509(T)=CIP 109821(T))

A Highly Pathogenic Strain of Staphylococcus sciuri Caused Fatal Exudative Epidermitis in Piglets

Staphylococcus sciuri are important human pathogens responsible for endocarditis, peritonitis, septic shock, urinary tract infection, pelvic inflammatory disease and wound infections. However, little information is known regarding the pathogenicity of S. sciuri to animals. From the pericardial fluid of a diseased piglet with exudative epidermitis (EE), we isolated a strain of Staphylococcus in pure culture. Surprisingly, this isolate was a member of S. sciuri rather than S. hyicus as identified by its biochemical traits and also by analysis of 23S ribosomal DNA using Internal Transcribed Spacer PCR. In addition, inoculation of newborn piglets with 1×10(10) CFU of the isolate by oral feeding or intra-muscular injection successfully reproduced EE in piglets, which suggested that the oral intake of the pathogen by the animals is one of the major routes of exposure. These unexpected findings prioritized S. sciuri as important zoonotic agents, which may have ramifications for human medicine

Structural variation and introgression from wild populations in East Asian cattle genomes confer adaptation to local environment

BACKGROUND: Structural variations (SVs) in individual genomes are major determinants of complex traits, including adaptability to environmental variables. The Mongolian and Hainan cattle breeds in East Asia are of taurine and indicine origins that have evolved to adapt to cold and hot environments, respectively. However, few studies have investigated SVs in East Asian cattle genomes and their roles in environmental adaptation, and little is known about adaptively introgressed SVs in East Asian cattle. RESULTS: In this study, we examine the roles of SVs in the climate adaptation of these two cattle lineages by generating highly contiguous chromosome-scale genome assemblies. Comparison of the two assemblies along with 18 Mongolian and Hainan cattle genomes obtained by long-read sequencing data provides a catalog of 123,898 nonredundant SVs. Several SVs detected from long reads are in exons of genes associated with epidermal differentiation, skin barrier, and bovine tuberculosis resistance. Functional investigations show that a 108-bp exonic insertion in SPN may affect the uptake of Mycobacterium tuberculosis by macrophages, which might contribute to the low susceptibility of Hainan cattle to bovine tuberculosis. Genotyping of 373 whole genomes from 39 breeds identifies 2610 SVs that are differentiated along a "north-south" gradient in China and overlap with 862 related genes that are enriched in pathways related to environmental adaptation. We identify 1457 Chinese indicine-stratified SVs that possibly originate from banteng and are frequent in Chinese indicine cattle. CONCLUSIONS: Our findings highlight the unique contribution of SVs in East Asian cattle to environmental adaptation and disease resistance

The Corrosion Behavior of Mg5Y in Nominally Distilled Water

This paper studies the macro and micro corrosion of Mg5Y in nominally distilled water. The Y-containing corrosion product film formed on the alloy surface provides some protection for the Mg matrix to the galvanic corrosion caused by Y-containing second-phase particles. In some cases, there is no corrosion of the matrix surrounding most of the second phase particles. However, about 2% of the second-phase particles in the as-cast Mg5Y causes micro-galvanic corrosion, resulting in 'bump' or 'volcano' shaped corrosion product deposit. These 'active particles' cannot be significantly reduced by solution-heat-treatment

The inhibitive effect of artificial seawater on magnesium corrosion

The corrosion behavior of pure magnesium (Mg) immersed in 3.5 wt% NaCl and artificial seawater is evaluated by immersion test, electrochemical impedance spectroscopy (EIS), polarization curve, scanning electrochemical microscopy (SECM), and corrosion morphology analysis. The results show that the corrosion rate of the pure Mg in the artificial seawater is nearly a half of that in the 3.5 wt% NaCl, and the serious localized corrosion of Mg in the NaCl is inhibited in the artificial seawater. The main constituents MgCl and NaSO in artificial seawater are found to be inhibitive for the corrosion of Mg. The presence of Mg ions could facilitate the formation of Mg(OH) film and thus to some extent retard the dissolution of Mg. The SO ions in the artificial seawater might be absorbed competitively against Cl on the Mg surface to retard the corrosion of Mg. The corrosive and inhibitive effects of other anions and cations on Mg dissolution in the artificial seawater were also briefly analyzed

Review of the atmospheric corrosion of magnesium alloys

Mg atmospheric corrosion is induced by a thin surface aqueous layer. Controlling factors are microgalvanic acceleration between different phases, protection by a continuous second phase distribution, protection by corrosion products, and degradation of protective layers by aggressive species such as chloride ions. The Mg atmospheric corrosion rate increases with relative humidity (RH) and concentrations of aggressive species. Temperature increases the corrosion rate unless a protective film causes a decrease. O, SO and NO accelerate the atmospheric corrosion rate, whereas the corrosion rate is decreased by CO. The traditional gravimetric method can evaluate effectively the corrosion behavior of Mg alloys