Federal University of São Carlos

About: Federal University of São Carlos is a education organization based out in São Carlos, Brazil. It is known for research contribution in the topics: Population & Microstructure. The organization has 16471 authors who have published 34057 publications receiving 456654 citations. The organization is also known as: UFSCar & Federal University of São Carlos.

The Genome Sequence of the Gram-Positive Sugarcane Pathogen Leifsonia xyli subsp. xyli

Abstract: The genome sequence of Leifsonia xyli subsp. xyli, which causes ratoon stunting disease and affects sugarcane worldwide, was determined. The single circular chromosome of Leifsonia xyli subsp. xyli CTCB07 was 2.6 Mb in length with a GC content of 68% and 2,044 predicted open reading frames. The analysis also revealed 307 predicted pseudogenes, which is more than any bacterial plant pathogen sequenced to date. Many of these pseudogenes, if functional, would likely be involved in the degradation of plant heteropolysaccharides, uptake of free sugars, and synthesis of amino acids. Although L. xyli subsp. xyli has only been identified colonizing the xylem vessels of sugarcane, the numbers of predicted regulatory genes and sugar transporters are similar to those in free-living organisms. Some of the predicted pathogenicity genes appear to have been acquired by lateral transfer and include genes for cellulase, pectinase, wilt-inducing protein, lysozyme, and desaturase. The presence of the latter may contribute to stunting, since it is likely involved in the synthesis of abscisic acid, a hormone that arrests growth. Our findings are consistent with the nutritionally fastidious behavior exhibited by L. xyli subsp. xyli and suggest an ongoing adaptation to the restricted ecological niche it inhabits.

Enhanced optical asymmetry in supramolecular chiroplasmonic assemblies with long-range order.

Abstract: Chiral assemblies of plasmonic nanoparticles are known for strong circular dichroism but not for high optical asymmetry, which is limited by the unfavorable combination of electrical and magnetic field components compounded by strong scattering. Here, we show that these limitations can be overcome by the long-range organization of nanoparticles in a manner similar to the liquid crystals and found in helical assemblies of gold nanorods with human islet amyloid polypeptides. A strong, polarization-dependent spectral shift and the reduced scattering of energy states with antiparallel orientation of dipoles activated in assembled helices increased optical asymmetry g-factors by a factor of more than 4600. The liquid crystal–like color variations and the nanorod-accelerated fibrillation enable drug screening in complex biological media. Improvement of long-range order can also provide structural guidance for the design of materials with high optical asymmetry.