Surface states on a topologically non-trivial semimetal: The case of Sb(110)

The electronic structure of Sb(110) is studied by angle-resolved photoemission spectroscopy and first-principle calculations, revealing several electronic surface states in the projected bulk band gaps around the Fermi energy. The dispersion of the states can be interpreted in terms of a strong spin-orbit splitting. The bulk band structure of Sb has the characteristics of a strong topological insulator with a Z2 invariant nu0=1. This puts constraints on the existence of metallic surface states and the expected topology of the surface Fermi contour. However, bulk Sb is a semimetal, not an insulator and these constraints are therefore partly relaxed. This relation of bulk topology and expected surface state dispersion for semimetals is discussed.Comment: 7 pages, 4 figure

Genetic Dissection of Disease Resistance to the Blue Mold Pathogen, \u3cem\u3ePeronospora tabacina\u3c/em\u3e, in Tobacco

Tobacco blue mold, caused by the obligately biotrophic oomycete pathogen Peronospora tabacina D.B. Adam, is a major foliar disease that results in significant losses in tobacco-growing areas. Natural resistance to P. tabacina has not been identified in any variety of common tobacco. Complete resistance, conferred by RBM1, was found in N. debneyi and was transferred into cultivated tobacco by crossing. In the present study, we characterized the RBM1-mediated resistance to blue mold in tobacco and show that the hypersensitive response (HR) plays an important role in the host defense reactions. Genetic mapping indicated that the disease resistance gene locus resides on chromosome 7. The genetic markers linked to this gene and the genetic map we generated will not only benefit tobacco breeders for variety improvement but will also facilitate the positional cloning of RBM1 for biologists

Computational prediction of novel non-coding RNAs in Arabidopsis thaliana

BackgroundNon-coding RNA (ncRNA) genes do not encode proteins but produce functional RNA molecules that play crucial roles in many key biological processes. Recent genome-wide transcriptional profiling studies using tiling arrays in organisms such as human and Arabidopsis have revealed a great number of transcripts, a large portion of which have little or no capability to encode proteins. This unexpected finding suggests that the currently known repertoire of ncRNAs may only represent a small fraction of ncRNAs of the organisms. Thus, efficient and effective prediction of ncRNAs has become an important task in bioinformatics in recent years. Among the available computational methods, the comparative genomic approach seems to be the most powerful to detect ncRNAs. The recent completion of the sequencing of several major plant genomes has made the approach possible for plants.ResultsWe have developed a pipeline to predict novel ncRNAs in the Arabidopsis (Arabidopsis thaliana) genome. It starts by comparing the expressed intergenic regions of Arabidopsis as provided in two whole-genome high-density oligo-probe arrays from the literature with the intergenic nucleotide sequences of all completely sequenced plant genomes including rice (Oryza sativa), poplar (Populus trichocarpa), grape (Vitis vinifera), and papaya (Carica papaya). By using multiple sequence alignment, a popular ncRNA prediction program (RNAz), wet-bench experimental validation, protein-coding potential analysis, and stringent screening against various ncRNA databases, the pipeline resulted in 16 families of novel ncRNAs (with a total of 21 ncRNAs).ConclusionIn this paper, we undertake a genome-wide search for novel ncRNAs in the genome of Arabidopsis by a comparative genomics approach. The identified novel ncRNAs are evolutionarily conserved between Arabidopsis and other recently sequenced plants, and may conduct interesting novel biological functions

the case of Sb(110)

The electronic structure of Sb(110) is studied by angle-resolved photoemission spectroscopy and first-principles calculations, revealing several electronic surface states in the projected bulk band gaps around the Fermi energy. The dispersion of the states can be interpreted in terms of a strong spin-orbit splitting. The bulk band structure of Sb has the characteristics of a strong topological insulator with a ℤ2 invariant ν0=1. This puts constraints on the existence of metallic surface states and the expected topology of the surface Fermi contour. However, bulk Sb is a semimetal, not an insulator, and these constraints are therefore partly relaxed. This relation of bulk topology and expected surface-state dispersion for semimetals is discussed

Identification and characterization of class E genes involved in floral organ development in Dianthus chinensis

The SEPALLATA (SEP) gene, as a 'glue' for the 'floral quartets model', plays an important role in floral organ development by forming tetramers with class A-, B-, and C- genes. The functional differentiation of class E genes has been reported in different species. Carnation (Dianthus spp.) is a world-famous economic flower that has been extensively used in landscaping, but the roles of SEP genes in carnation are unclear. Here, we found that the class E genes of D. chinensis cultivar 'L' showed different expression patterns during floral organ primordium development by transcriptome analysis. Combined with quantitative real-time PCR, its tissue and specific stage expression patterns were also different in different subclades. In addition, a yeast two-hybrid experiment was carried out to explore the interaction patterns of class E genes with other class A-, B-, and C- genes. Only DcSEP3s and DcSEP4s proteins interacted with all three classes of A-, B-, and C- proteins, and interestingly, is that DcSEP3-1 only interacted with the DcAP1 protein of class A, while the DcSEP3-2 protein only interacted with DcFUL1. Transgenic experiments showed that overexpression of DcSEP3-2 genes in Arabidopsis resulted in early flowering, smaller rosettes, dwarfism and abnormal floral organs. The transgenic line overexpressing of DcSEP3-1 only showed an early flowering phenotype. All these results indicated that the two DcSEP3s of class E genes in D. chinensis may undergo sub-functionalization. These findings advance our understanding of the molecular mechanisms of flower development in carnation

Association of dietary fat intake with skeletal muscle mass and muscle strength in adults aged 20–59: NHANES 2011–2014

BackgroundSarcopenia, a progressive loss of skeletal muscle mass and strength, needs to initially prevent in the twenties. Meanwhile, there is a lack of research on the effects of fat consumption on skeletal muscle mass and strength in adults aged 20–59. We aimed to assess associations between dietary fat intake and skeletal muscle mass, as measured by appendicular lean mass adjusted for body mass index (ALMBMI), and muscle strength, as represented by handgrip strength adjusted for body mass index (GSMAXBMI), among adults aged 20–59.MethodsDietary fat intake per kilogram of actual body weight was assessed using two 24h recalls, while ALM and GSMAX were measured using DXA and a handgrip dynamometer, respectively. A weighted multiple linear regression model was employed to analyze the association between dietary fat intake and skeletal muscle mass, utilizing data from the National Health and Nutrition Examination Survey spanning from 2011 to 2014. To assess the non-linear relationship and saturation value between dietary fat intake and skeletal muscle mass, a smooth curve fitting approach and a saturation effect analysis model were utilized.ResultsThe study comprised a total of 5356 subjects. After adjusting for confounding factors, there was a positive association observed between dietary fat intake and ALMBMI as well as GSMAXBMI. The relationship between dietary fat intake and ALMBMI showed an inverted U-shaped curve, as did the association with GSMAXBMI. Turning points were observed at 1.88 g/kg/d for total fat intake and ALMBMI, as well as at 1.64 g/kg/d for total fat intake and GSMAXBMI. Furthermore, turning points were still evident when stratifying by gender, age, protein intake, and physical activity. The turning points were lower in individuals with low protein intake(<0.8 g/kg/d) and high levels of physical activity.ConclusionThe moderate dietary fat intake can be beneficial for muscle mass and strength in adults aged 20–59 under specific conditions. Special attention should be directed toward the consumption of fats in individuals with low protein intake and those engaged in high levels of physical activity