100 research outputs found

    Stein's method and the multivariate CLT for traces of powers on the classical compact groups

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    Let MnM_n be a random element of the unitary, special orthogonal, or unitary symplectic groups, distributed according to Haar measure. By a classical result of Diaconis and Shahshahani, for large matrix size nn, the vector (\on{Tr}(M_n), \on{Tr}(M_n^2),..., \on{Tr}(M_n^d)) tends to a vector of independent (real or complex) Gaussian random variables. Recently, Jason Fulman has demonstrated that for a single power jj (which may grow with nn), a speed of convergence result may be obtained via Stein's method of exchangeable pairs. In this note, we extend Fulman's result to the multivariate central limit theorem for the full vector of traces of powers.Comment: Main result strengthened, proof of Prop. 1.3 adde

    A quantitative central limit theorem for linear statistics of random matrix eigenvalues

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    It is known that the fluctuations of suitable linear statistics of Haar distributed elements of the compact classical groups satisfy a central limit theorem. We show that if the corresponding test functions are sufficiently smooth, a rate of convergence of order almost 1/n1/n can be obtained using a quantitative multivariate CLT for traces of powers that was recently proven using Stein's method of exchangeable pairs.Comment: Title modified; main result stated under slightly weaker conditions; accepted for publication in the Journal of Theoretical Probabilit

    Fatal affairs - conjugational transfer of a dinoflagellate-killing plasmid between marine Rhodobacterales

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    The roseobacter group of marine bacteria is characterized by a mosaic distribution of ecologically important phenotypes. These are often encoded on mobile extrachromosomal replicons. So far, conjugation had only been experimentally proven between the two model organisms Phaeobacter inhibens and Dinoroseobacter shibae. Here, we show that two large natural RepABC-type plasmids from D. shibae can be transferred into representatives of all known major Rhodobacterales lineages. Complete genome sequencing of the newly established Phaeobacter inhibens transconjugants confirmed their genomic integrity. The conjugated plasmids were stably maintained as single copy number replicons in the genuine as well as the new host. Co-cultivation of Phaeobacter inhibens and the transconjugants with the dinoflagellate Prorocentrum minimum demonstrated that Phaeobacter inhibens is a probiotic strain that improves the yield and stability of the dinoflagellate culture. The transconjugant carrying the 191 kb plasmid, but not the 126 kb sister plasmid, killed the dinoflagellate in co-culture

    Strategi Pembangunan Pariwisata melalui Sinergitas Dinas Pariwisata dengan Desa Adat ( Studi Kasus pada Pengelolaan Obyek Wisata Pantai Labuan Sait dalam Meningkatkan Retribusi Daerah di Kabupaten Badung)

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    A gradual Tourism development is very important to improve the quality of tourism each year to compete with other tourist attraction. The synergy between the Central Government with local government plays an important role to the development of tourism. The background to this research is the development of tourism which is still insufficient in Labuan Sait both in terms of means and infrastructure, promotion, as well as structuring tourism. This study measures how does tourism development strategy through the synergy with the customary village tourism office on the management of Beach Tourism Labuan Sait in increasing the levy County in Badung Regency with the theory of development that uses the concept of planning development by Sjahrizal in the regional development planning in the era of autonomy. The indicator consists of planning, implementation, monitoring and evaluation. In addition also use the concept of synergy from Najiyati and Rahmat which consists of indicators communication and coordination as well as indicators of the SWOT by Freddy Rangkuti. Method used in this study is a qualitative method with descriptive approach with data collection techniques in the form of in-depth interviews to several informants associated with this research. The results of the research showed that the development strategy of tourism through the synergy with the customary village Tourism Office on the management of Beach Tourism Labuan Sait in improving regional levies in Badung Regency are still insufficient. That is because the is still lacking from the indicator monitoring and implementation and evaluation of the impact against the decline of levy of admission attractions Labuan Sait in the 2017.     Keywords: Development, Tourism, Synergy, and Strateg

    Characterization of the Metabolically Modified Heavy Metal-Resistant Cupriavidus metallidurans Strain MSR33 Generated for Mercury Bioremediation

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    BACKGROUND: Mercury-polluted environments are often contaminated with other heavy metals. Therefore, bacteria with resistance to several heavy metals may be useful for bioremediation. Cupriavidus metallidurans CH34 is a model heavy metal-resistant bacterium, but possesses a low resistance to mercury compounds. METHODOLOGY/PRINCIPAL FINDINGS: To improve inorganic and organic mercury resistance of strain CH34, the IncP-1β plasmid pTP6 that provides novel merB, merG genes and additional other mer genes was introduced into the bacterium by biparental mating. The transconjugant Cupriavidus metallidurans strain MSR33 was genetically and biochemically characterized. Strain MSR33 maintained stably the plasmid pTP6 over 70 generations under non-selective conditions. The organomercurial lyase protein MerB and the mercuric reductase MerA of strain MSR33 were synthesized in presence of Hg(2+). The minimum inhibitory concentrations (mM) for strain MSR33 were: Hg(2+), 0.12 and CH(3)Hg(+), 0.08. The addition of Hg(2+) (0.04 mM) at exponential phase had not an effect on the growth rate of strain MSR33. In contrast, after Hg(2+) addition at exponential phase the parental strain CH34 showed an immediate cessation of cell growth. During exposure to Hg(2+) no effects in the morphology of MSR33 cells were observed, whereas CH34 cells exposed to Hg(2+) showed a fuzzy outer membrane. Bioremediation with strain MSR33 of two mercury-contaminated aqueous solutions was evaluated. Hg(2+) (0.10 and 0.15 mM) was completely volatilized by strain MSR33 from the polluted waters in presence of thioglycolate (5 mM) after 2 h. CONCLUSIONS/SIGNIFICANCE: A broad-spectrum mercury-resistant strain MSR33 was generated by incorporation of plasmid pTP6 that was directly isolated from the environment into C. metallidurans CH34. Strain MSR33 is capable to remove mercury from polluted waters. This is the first study to use an IncP-1β plasmid directly isolated from the environment, to generate a novel and stable bacterial strain useful for mercury bioremediation

    Carolacton Treatment Causes Delocalization of the Cell Division Proteins PknB and DivIVa in Streptococcus mutans in vivo.

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    The small inhibitory molecule Carolacton has been shown to cause chain formation and bulging in Streptococci, suggesting a defect in cell division, but it is not known how cell division is impaired on a molecular level. Fluorescent fusion proteins have successfully been applied to visualize protein localization and dynamics in vivo and have revolutionized our understanding of cell wall growth, cell division, chromosome replication and segregation. However, in Streptococci the required vectors are largely lacking. We constructed vectors for chromosomal integration and inducible expression of fluorescent fusion proteins based on GFP+ in S. mutans. Their applicability was verified using four proteins with known localization in the cell. We then determined the effect of Carolacton on the subcellular localization of GFP+ fusions of the cell division protein DivIVa and the serine-threonine protein kinase PknB. Carolacton caused a significant delocalization of these proteins from midcell, in accordance with a previous study demonstrating the Carolacton insensitive phenotype of a pknB deletion strain. Carolacton treated cells displayed an elongated phenotype, increased septum formation and a severe defect in daughter cell separation. GFP+ fusions of two hypothetical proteins (SMU_503 and SMU_609), that had previously been shown to be the most strongly upregulated genes after Carolacton treatment, were found to be localized at the septum in midcell, indicating their role in cell division. These findings highlight the importance of PknB as a key regulator of cell division in streptococci and indicate a profound impact of Carolacton on the coordination between peripheral and septal cell wall growth. The established vector system represents a novel tool to study essential steps of cellular metabolism

    The Alternative Sigma Factor SigX Controls Bacteriocin Synthesis and Competence, the Two Quorum Sensing Regulated Traits in Streptococcus mutans.

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    Two small quorum sensing (QS) peptides regulate competence in S. mutans in a cell density dependent manner: XIP (sigX inducing peptide) and CSP (competence stimulating peptide). Depending on the environmental conditions isogenic S. mutans cells can split into a competent and non-competent subpopulation. The origin of this population heterogeneity has not been experimentally determined and it is unknown how the two QS systems are connected. We developed a toolbox of single and dual fluorescent reporter strains and systematically knocked out key genes of the competence signaling cascade in the reporter strain backgrounds. By following signal propagation on the single cell level we discovered that the master regulator of competence, the alternative sigma factor SigX, directly controls expression of the response regulator for bacteriocin synthesis ComE. Consequently, a SigX binding motif (cin-box) was identified in the promoter region of comE. Overexpressing the genetic components involved in competence development demonstrated that ComRS represents the origin of bimodality and determines the modality of the downstream regulators SigX and ComE. Moreover these analysis showed that there is no direct regulatory link between the two QS signaling cascades. Competence is induced through a hierarchical XIP signaling cascade, which has no regulatory input from the CSP cascade. CSP exclusively regulates bacteriocin synthesis. We suggest renaming it mutacin inducing peptide (MIP). Finally, using phosphomimetic comE mutants we show that unimodal bacteriocin production is controlled posttranslationally, thus solving the puzzling observation that in complex media competence is observed in a subpopulation only, while at the same time all cells produce bacteriocins. The control of both bacteriocin synthesis and competence through the alternative sigma-factor SigX suggests that S. mutans increases its genetic repertoire via QS controlled predation on neighboring species in its natural habitat
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