285 research outputs found

    Structural studies of 1:1 quinone-hydroquinone complexes

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    The structures of the 1:1 quinone-hydroquinone complexes of 2-phenyl and of 2-(4'-chloro) phenylbenzoquinone have been studied by X-ray methods. A superficial study would indicate that the quinhydrones are centrosymmetric and belong to the space group P21/c. However, other evidence indicates that the true crystal structure may belong to either the space group P21 or to Pc, or that the crystal may contain regions that would coresspond to each of these two non-centrosymmetric space groups. Some possible consequences of such a structural arrangement are briefly discussed

    In Stories We Trust: Studies of the Validity of Autobiographies

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    There is a dearth of research addressing the validity of life stories, or autobiographies. In part, this is because it is unclear how such data sources might be validated. This article recommends two differ-ent perspectives for obtaining evidence relevant to the validity of autobiographical data. A study is conducted from each of these perspectives, and multiple validity estimates are obtained in each in-vestigation. The construct validity of standard psychological constructs (e.g., assertiveness, trustwor-thiness) obtained in Study 1 from autobiographies was equal to that of standard instruments designed to assess these constructs. Evidence for the validity of life themes, extracted from autobi-ographies in Study 2, was also apparent. Because life histories, autobiographies, and case studies are relied on heavily in the practice of counseling psychology and are rapidly regaining popularity in scientific studies, these positive findings suggest the wisdom in this increasing use of life history data

    In stories we trust: Studies of the validity of autobiographies.

    Get PDF

    In Stories We Trust: Studies of the Validity of Autobiographies

    Get PDF
    There is a dearth of research addressing the validity of life stories, or autobiographies. In part, this is because it is unclear how such data sources might be validated. This article recommends two differ-ent perspectives for obtaining evidence relevant to the validity of autobiographical data. A study is conducted from each of these perspectives, and multiple validity estimates are obtained in each in-vestigation. The construct validity of standard psychological constructs (e.g., assertiveness, trustwor-thiness) obtained in Study 1 from autobiographies was equal to that of standard instruments designed to assess these constructs. Evidence for the validity of life themes, extracted from autobi-ographies in Study 2, was also apparent. Because life histories, autobiographies, and case studies are relied on heavily in the practice of counseling psychology and are rapidly regaining popularity in scientific studies, these positive findings suggest the wisdom in this increasing use of life history data

    In stories we trust: Studies of the validity of autobiographies.

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    Defects in death-inducing signalling complex formation prevent JNK activation and Fas-mediated apoptosis in DU 145 prostate carcinoma cells

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    Androgen-independent prostate carcinomas are resistant to chemotherapy and cell lines derived from androgen-independent prostate carcinomas such as DU 145 cells are highly resistant to Fas-mediated apoptosis. The incubation of DU 145 cells with anti-Fas IgM agonistic antibody of Fas receptor fails to activate JNK, a stress kinase involved in regulating apoptosis. We have previously shown that JNK activation is sufficient and necessary to promote Fas-mediated apoptosis in DU 145 cells. We investigate the mechanisms by which JNK activation and apoptosis are abrogated. HSP27 is overexpressed in DU 145 cells and has previously been reported to sequester DAXX and prevent JNK activation in cells treated with anti-Fas IgM. However, we find no evidence that HSP27 interacts with DAXX in DU 145 cells. Instead, we find that FADD does not interact with caspase-8 and this results in defective death-inducing signalling complex formation following Fas receptor activation

    Insights into the Dekkera bruxellensis genomic landscape: comparative genomics reveals variations in ploidy and nutrient utilisation potential amongst wine isolates

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    The yeast Dekkera bruxellensis is a major contaminant of industrial fermentations, such as those used for the production of biofuel and wine, where it outlasts and, under some conditions, outcompetes the major industrial yeast Saccharomyces cerevisiae. In order to investigate the level of inter-strain variation that is present within this economically important species, the genomes of four diverse D. bruxellensis isolates were compared. While each of the four strains was shown to contain a core diploid genome, which is clearly sufficient for survival, two of the four isolates have a third haploid complement of chromosomes. The sequences of these additional haploid genomes were both highly divergent from those comprising the diploid core and divergent between the two triploid strains. Similar to examples in the Saccharomyces spp. clade, where some allotriploids have arisen on the basis of enhanced ability to survive a range of environmental conditions, it is likely these strains are products of two independent hybridisation events that may have involved multiple species or distinct sub-species of Dekkera. Interestingly these triploid strains represent the vast majority (92%) of isolates from across the Australian wine industry, suggesting that the additional set of chromosomes may confer a selective advantage in winery environments that has resulted in these hybrid strains all-but replacing their diploid counterparts in Australian winery settings. In addition to the apparent inter-specific hybridisation events, chromosomal aberrations such as strain-specific insertions and deletions and loss-of-heterozygosity by gene conversion were also commonplace. While these events are likely to have affected many phenotypes across these strains, we have been able to link a specific deletion to the inability to utilise nitrate by some strains of D. bruxellensis, a phenotype that may have direct impacts in the ability for these strains to compete with S. cerevisiae.Anthony R. Borneman, Ryan Zeppel, Paul J. Chambers, Chris D. Curti

    Comprehensive Bayesian analysis of FRB-like bursts from SGR 1935+2154 observed by CHIME/FRB

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    The bright millisecond-duration radio burst from the Galactic magnetar SGR 1935+2154 in 2020 April was a landmark event, demonstrating that at least some fast radio burst (FRB) sources could be magnetars. The two-component burst was temporally coincident with peaks observed within a contemporaneous short X-ray burst envelope, marking the first instance where FRB-like bursts were observed to coincide with X-ray counterparts. In this study, we detail five new radio burst detections from SGR 1935+2154, observed by the CHIME/FRB instrument between October 2020 and December 2022. We develop a fast and efficient Bayesian inference pipeline that incorporates state-of-the-art Markov chain Monte Carlo techniques and use it to model the intensity data of these bursts under a flexible burst model. We revisit the 2020 April burst and corroborate that both the radio sub-components lead the corresponding peaks in their high-energy counterparts. For a burst observed in 2022 October, we find that our estimated radio pulse arrival time is contemporaneous with a short X-ray burst detected by GECAM and HEBS, and Konus-Wind and is consistent with the arrival time of a radio burst detected by GBT. We present flux and fluence estimates for all five bursts, employing an improved estimator for bursts detected in the side-lobes. We also present upper limits on radio emission for X-ray emission sources which were within CHIME/FRB's field-of-view at trigger time. Finally, we present our exposure and sensitivity analysis and estimate the Poisson rate for FRB-like events from SGR 1935+2154 to be 0.005−0.004+0.0820.005^{+0.082}_{-0.004} events/day above a fluence of 10 kJy ms10~\mathrm{kJy~ms} during the interval from 28 August 2018 to 1 December 2022, although we note this was measured during a time of great X-ray activity from the source.Comment: 22 pages, 6 figures, 4 tables. To be submitted to Ap
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