242 research outputs found

    Intolerance of Uncertainty as a Contributor to Fear and Avoidance Symptoms of Panic Attacks

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    Panic disorder symptoms are persistent for 50–80% of cases even after treatment, resulting in experiences of disability and dissatisfaction in life. Previous research has focused on anxiety sensitivity (AS) and its dimensions as contributing to symptoms of panic disorder; however, recent research has suggested that intolerance of uncertainty (IU)—the tendency for a person to consider the possibility of a negative event occurring as threatening, irrespective of the actual probability of its occurrence—may also play a critical role. The current study was designed to assess the specific relationships between dimensions of IU (i.e. prospective IU and inhibitory IU) and the fear and avoidance symptoms associated with panic disorder. Participants included 122 community members (81% women) with a history of at least one panic attack who participated in a larger study on fear. Participants completed measures of AS, IU, and panic disorder symptoms. Correlation and regression analyses supported a significant and substantial relationship between AS, inhibitory IU, and panic disorder symptoms. Inhibitory IU accounted for relatively more variance in avoidance symptoms related to panic disorder than did the fears of physical sensations dimension of AS. As such, further investigation of the role of IU in panic disorder symptoms appears warranted. Comprehensive results, implications, and directions for future research are discussed

    Identification of a polyketide synthase required for alternariol (AOH) and alternariol-9-methyl ether (AME) formation in Alternaria alternata

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    Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH) and alternariol-9-methyl ether (AME) are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS). In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH, correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR, involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production

    Biodegradation kinetics of 4-fluorocinnamic acid by a consortium of Arthrobacter and Ralstonia strains

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    Arthrobacter sp. strain G1 is able to grow on 4-fluorocinnamic acid (4-FCA) as sole carbon source. The organism converts 4-FCA into 4-fluorobenzoic acid (4-FBA) and utilizes the two-carbon side-chain for growth with some formation of 4-fluoroacetophenone as a dead-end side product. We also have isolated Ralstonia sp. strain H1, an organism that degrades 4-FBA. A consortium of strains G1 and H1 degraded 4-FCA with Monod kinetics during growth in batch and continuous cultures. Specific growth rates of strain G1 and specific degradation rates of 4-FCA were observed to follow substrate inhibition kinetics, which could be modeled using the kinetic models of Haldane–Andrew and Luong–Levenspiel. The mixed culture showed complete mineralization of 4-FCA with quantitative release of fluoride, both in batch and continuous cultures. Steady-state chemostat cultures that were exposed to shock loadings of substrate responded with rapid degradation and returned to steady-state in 10–15 h, indicating that the mixed culture provided a robust system for continuous 4-FCA degradation

    Discovery and characterisation of two Neptune-mass planets orbiting HD 212729 with TESS

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    We report the discovery of two exoplanets orbiting around HD 212729 (TOI\,1052, TIC 317060587), a Teff=6146T_{\rm eff}=6146K star with V=9.51 observed by TESS in Sectors 1 and 13. One exoplanet, TOI-1052b, is Neptune-mass and transits the star, and an additional planet TOI-1052c is observed in radial velocities but not seen to transit. We confirm the planetary nature of TOI-1052b using precise radial velocity observations from HARPS and determined its parameters in a joint RV and photometry analysis. TOI-1052b has a radius of 2.870.24+0.292.87^{+0.29}_{-0.24} R_{\oplus}, a mass of 16.9±1.716.9\pm 1.7 M_{\oplus}, and an orbital period of 9.14 days. TOI-1052c does not show any transits in the TESS data, and has a minimum mass of 34.33.7+4.134.3^{+4.1}_{-3.7} M_{\oplus} and an orbital period of 35.8 days, placing it just interior to the 4:1 mean motion resonance. Both planets are best fit by relatively high but only marginally significant eccentricities of 0.180.07+0.090.18^{+0.09}_{-0.07} for planet b and 0.240.08+0.090.24^{+0.09}_{-0.08} for planet c. We perform a dynamical analysis and internal structure model of the planets as well as deriving stellar parameters and chemical abundances. The mean density of TOI-1052b is 3.91.3+1.73.9^{+1.7}_{-1.3} g cm3^{-3} consistent with an internal structure similar to Neptune. A nearby star is observed in Gaia DR3 with the same distance and proper motion as TOI-1052, at a sky projected separation of ~1500AU, making this a potential wide binary star system.Comment: Accepted to MNRAS. 11 page
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