29 research outputs found

    Ion-Induced Dipole Interactions and Fragmentation Times : Cα\alpha -Cβ\beta Chromophore Bond Dissociation Channel

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    The fragmentation times corresponding to the loss of the chromophore (Cα\alpha-- Cβ\beta bond dissociation channel) after photoexcitation at 263 nm have been investigated for several small peptides containing tryptophan or tyrosine. For tryptophan-containing peptides, the aromatic chromophore is lost as an ionic fragment (m/z 130), and the fragmentation time increases with the mass of the neutral fragment. In contrast, for tyrosine-containing peptides the aromatic chromophore is always lost as a neutral fragment (mass = 107 amu) and the fragmentation time is found to be fast (\textless{}20 ns). These different behaviors are explained by the role of the postfragmentation interaction in the complex formed after the Cα\alpha--Cβ\beta bond cleavage

    Mental health literacy of depression: gender differences and attitudinal antecedents in a representative British sample

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    Background Poor mental health literacy and negative attitudes toward individuals with mental health disorders may impede optimal help-seeking for symptoms of mental ill-health. The present study examined the ability to recognize cases of depression as a function of respondent and target gender, as well as individual psychological differences in attitudes toward persons with depression. Methods In a representative British general population survey, the ability to correctly recognize vignettes of depression was assessed among 1,218 adults. Respondents also rated the vignettes along a number of attitudinal dimensions and completed measures of attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes. Results There were significant differences in the ability to correctly identify cases of depression as a function of respondent and target gender. Respondents were more likely to indicate that a male vignette did not suffer from a mental health disorder compared to a female vignette, and women were more likely than men to indicate that the male vignette suffered from a mental health disorder. Attitudes toward persons with depression were associated with attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes. Conclusion Initiatives that consider the impact of gender stereotypes as well as individual differences may enhance mental health literacy, which in turn is associated with improved help-seeking behaviors for symptoms of mental ill-health

    Factors influencing attitudes towards seeking professional psychological help among South Asian students in Britain

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    The present study examined the associations between attitudes towards seeking professional psychological help (ATSPPH), adherence to Asian values, cultural mistrust, and salience of ethnic identity in a sample of South Asian university students in Britain. A total of 148 participants completed a survey consisting of measures of the afore-mentioned variables, and provided their demographic details. Preliminary analyses showed that women held significantly more positive ATSPPH than men (  = 0.51); there were also small differences between participants of Indian, Pakistani, and other South Asian descent. Further analyses revealed that ATSPPH was significantly predicted by ethnic identity, cultural mistrust, and adherence to Asian values, once the effects of participant sex and ethnicity had been partialled out. The implications of these results for promoting mental health care utilisation among South Asian students are discussed in conclusion

    Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet synchrotron ionization quadrupole mass spectrometry: Application to low-temperature kinetics and product detection

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    A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radicalneutralchemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has beendeveloped that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion withexcellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by theairfoil is negligible. The reaction of C2H with C2H2 is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification basedon the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic ratesclose to the collision-determined limit
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