41 research outputs found
Production of siderophores increases resistance to fusaric acid in Pseudomonas protegens Pf-5
e0117040Fusaric acid is produced by pathogenic fungi of the genus Fusarium, and is toxic to plants and rhizobacteria. Many fluorescent pseudomonads can prevent wilt diseases caused by these fungi. This study was undertaken to evaluate the effect of fusaric acid on P. protegens Pf-5 and elucidate the mechanisms that enable the bacterium to survive in the presence of the mycotoxin. The results confirm that fusaric acid negatively affects growth and motility of P. protegens. Moreover, a notable increase in secretion of the siderophore pyoverdine was observed when P. protegens was grown in the presence of fusaric acid. Concomitantly, levels of enzymes involved in the biosynthesis of pyoverdine and enantio-pyochelin, the second siderophore encoded by P. protegens, increased markedly. Moreover, while similar levels of resistance to fusaric acid were observed for P. protegens mutants unable to synthesize either pyoverdine or enanto-pyochelin and the wild type strain, a double mutant unable to synthesize both kinds of siderophores showed a dramatically reduced resistance to this compound. This reduced resistance was not observed when this mutant was grown under conditions of iron excess. Spectrophotometric titrations revealed that fusaric acid binds not only Fe2+ and Fe3+, but also Zn2+, Mn2+ and Cu2+, with high affinity. Our results demonstrate that iron sequestration accounts at least in part for the deleterious effect of the mycotoxin on P. protegens
Plasma homocysteine levels and associated factors in community-dwelling adolescents: the EVA-TYROL study
BackgroundHomocysteine (Hcy) has been associated with an adverse cardiovascular risk profile in adolescents. Assessment of the association between plasma Hcy levels and clinical/laboratory factors might improve our understanding of the pathogenesis of cardiovascular disease.MethodsHcy was measured in 1,900 14- to 19-year-old participants of prospective population-based EVA-TYROL Study (44.3% males, mean age 16.4 years) between 2015 and 2018. Factors associated with Hcy were assessed by physical examination, standardized interviews, and fasting blood analysis.ResultsMean plasma Hcy was 11.3 ± 4.5 µmol/L. Distribution of Hcy was characterized by extreme right skew. Males exhibited higher Hcy and sex differences increased with increasing age. Univariate associations with Hcy emerged for age, sex, body mass index, high-density lipoprotein cholesterol, and for factors pertaining to blood pressure, glucose metabolism, renal function, and diet quality, whereas the most important multivariate predictors of Hcy were sex and creatinine.DiscussionClinical and laboratory factors associated with Hcy in adolescents were manifold, with sex and high creatinine identified as strongest independent determinants. These results may aid when interpreting future studies investigating the vascular risk of homocysteine
Inequivalent quantization of the rational Calogero model with a Coulomb type interaction
We consider the inequivalent quantizations of a -body rational Calogero
model with a Coulomb type interaction. It is shown that for certain range of
the coupling constants, this system admits a one-parameter family of
self-adjoint extensions. We analyze both the bound and scattering state sectors
and find novel solutions of this model. We also find the ladder operators for
this system, with which the previously known solutions can be constructed.Comment: 15 pages, 3 figures, revtex4, typos corrected, to appear in EPJ
Amino acid transport systems of lysosomes: Possible substitute utility of a surviving transport system for one congenitally defective or absent
Ways in which other transport systems may compensate for one that is genetically defective are considered. Comparisons of the transport systems of organelles (here the lysosome) with the transport system at the plasma membrane has significant implications for chemotherapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44194/1/10540_2005_Article_BF01116456.pd
25th Annual Computational Neuroscience Meeting: CNS-2016
Abstracts of the 25th Annual Computational Neuroscience
Meeting: CNS-2016
Seogwipo City, Jeju-do, South Korea. 2–7 July 201
Radiation emitted by a source orbiting a Schwarzschild--anti--de Sitter black hole
We study the scalar radiation emitted by a source orbiting a
Schwarzschild--anti--de Sitter black hole in circular geodesics. We obtain the
emitted power using quantum field theory in curved spacetimes at tree level
with reflective boundary conditions at infinity. We compare our results with
the ones obtained in Schwarzschild and Schwarzschild--de Sitter ()
spacetimes. In the Schwarzschild-de Sitter spacetime we observe an enhancement
of the emitted power associated to the lower multipole modes, when compared
with the Schwarzschild case. In contrast, for the Schwarzschild-anti-de Sitter
spacetime, the enhancement is rather of the higher multipole modes.Comment: 10 pages, 6 figure