118 research outputs found

    An Investigation of the Effect of Irrelevant Sounds on Serial Order Recall in Children and Adults

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    Irrelevant sound is detrimental to performance on serial order recall for both adults and children. Many current models of the effects of irrelevant sound on serial order recall propose that the irrelevant sound interferes with rehearsal in adults. However a direct test of rehearsal on the irrelevant sound effect (ISE) had not been examined prior to the present study. Furthermore, the cause of the ISE in children remains unclear as children are less proficient at rehearsal, yet typically show larger effects. We examined how certain factors hypothesized to relate to the size of the ISE correlate to performance in both adults and children in order to investigate the underlying mechanisms causing the effect in the two populations. Results indicated that in adults, while rehearsal does significantly predict the size of the ISE, the size of the relationship is weak. In children, the relationship between rehearsal and the size of the ISE appears stronger, however further analysis leads to the conclusion that attention capture may be playing a unique role in causing the ISE in children despite being shown not to play a role in adults. The present study demonstrates the need for further investigation not only into the cause of the ISE, but also into developmental differences in auditory distraction

    Experimentally Examining the Proposed Relationships Among “Rehearsal-based” Effects

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    Despite the importance of rehearsal to most models of verbal working memory, its role has been recently called into question. Much prior work in support of rehearsal models has centered on the experimental effects of word-length, phonological-similarity, and irrelevant sound on serial order recall performance and the interaction of all three with concurrent articulation. However, recent research has suggested that confounding effects of stimuli, such as orthographic neighborhood, may be the true cause of the word-length effect. While these findings alone have significant implications for modern models of rehearsal, to understand them within the context of modern theories of working memory, they must also be examined through the lens of the phonological-similarity and irrelevant-sound effects. Thus, through a series of three experiments, the influence of neighborhood in each of these effects was assessed, using strict controls for both orthographic and phonological neighborhood size. The word-length effect was significantly reversed; longer words were significantly better recalled than short words. However, the phonological-similarity effect remained significant even when neighborhood size was controlled. The irrelevant-sound effect was significant when stimuli had no orthographic or phonological neighbors, but was eliminated when stimuli had both. These findings present significant problems for common memory models that include a role for rehearsal, as the relationship between “rehearsal-based” effects was more tenuous than may have otherwise been anticipated

    Direct radiative effect of aerosols emitted by transport from road, shipping and aviation

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    Aerosols and their precursors are emitted abundantly by transport activities. Transportation constitutes one of the fastest growing activities and its growth is predicted to increase significantly in the future. Previous studies have estimated the aerosol direct radiative forcing from one transport sub-sector, but only one study to our knowledge estimated the range of radiative forcing from the main aerosol components (sulphate, black carbon (BC) and organic carbon) for the whole transportation sector. In this study, we compare results from two different chemical transport models and three radiation codes under different hypothesis of mixing: internal and external mixing using emission inventories for the year 2000. The main results from this study consist of a positive direct radiative forcing for aerosols emitted by road traffic of +20±11 mW m−2 for an externally mixed aerosol, and of +32±13 mW m−2 when BC is internally mixed. These direct radiative forcings are much higher than the previously published estimate of +3±11 mW m−2. For transport activities from shipping, the net direct aerosol radiative forcing is negative. This forcing is dominated by the contribution of the sulphate. For both an external and an internal mixture, the radiative forcing from shipping is estimated at −26±4 mW m−2. These estimates are in very good agreement with the range of a previously published one (from −46 to −13 mW m−2) but with a much narrower range. By contrast, the direct aerosol forcing from aviation is estimated to be small, and in the range −0.9 to +0.3 mW m−2

    Meta-analysis of indoor temperatures in new-build housing

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    Despite growing concerns about overheating, a lack of evidence exists on the scale of the problem, particularly in contemporary UK housing. This paper presents the results of a meta-analysis of indoor temperatures in selected low-energy housing. Temperature data recorded at five-minute intervals in 60 dwellings across 19 demonstration projects (2012–14) were collated and analysed to investigate the prevalence of overheating. Findings evidence high summertime temperatures, with 27% of living rooms exceeding 28°C during August. Based on the Chartered Institution of Building Services Engineers (CIBSE) threshold of 5% annual occupied hours > 25°C, 57% of bedrooms and 75% of living rooms were classified as having overheated. Overall, 30% of living rooms exceeded the adaptive comfort threshold of > 3% occupied hours ΔT ≄ 1 K. The results suggest a fundamental relationship between ventilation and indoor temperatures. The higher minimum and average summertime temperatures observed in mechanical ventilation with heat recovery (MVHR) homes (p < 0.05) and lower temperature range (p < 0.001) suggest the need for greater attention to adequate summertime ventilation provision in airtight homes. The results demonstrate a high prevalence of overheating in exemplary housing, indicating the need for greater efforts to ensure the effective implementation of strategies to minimize overheating and improve ventilation in low-energy homes

    Federal and state cooperation necessary but not sufficient for effective regional mental health systems : insights from systems modelling and simulation

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    For more than a decade, suicide rates in Australia have shown no improvement despite significant investment in reforms to support regionally driven initiatives. Further recommended reforms by the Productivity Commission call for Federal and State and Territory Government funding for mental health to be pooled and new Regional Commissioning Authorities established to take responsibility for efficient and effective allocation of ‘taxpayer money.’ This study explores the sufficiency of this recommendation in preventing ongoing policy resistance. A system dynamics model of pathways between psychological distress, the mental health care system, suicidal behaviour and their drivers was developed, tested, and validated for a large, geographically diverse region of New South Wales; the Hunter New England and Central Coast Primary Health Network (PHN). Multi-objective optimisation was used to explore potential discordance in the best-performing programs and initiatives (simulated from 2021 to 2031) across mental health outcomes between the two state-governed Local Health Districts (LHDs) and the federally governed PHN. Impacts on suicide deaths, mental health-related emergency department presentations, and service disengagement were explored. A combination of family psychoeducation, post-attempt aftercare, and safety planning, and social connectedness programs minimises the number of suicides across the PHN and in the Hunter New England LHD (13.5% reduction; 95% interval, 12.3–14.9%), and performs well in the Central Coast LHD (14.8% reduction, 13.5–16.3%), suggesting that aligned strategic decision making between the PHN and LHDs would deliver substantial impacts on suicide. Results also highlighted a marked trade-off between minimising suicide deaths versus minimising service disengagement. This is explained in part by the additional demand placed on services of intensive suicide prevention programs leading to increases in service disengagement as wait times for specialist community based mental health services and dissatisfaction with quality of care increases. Competing priorities between the PHN and LHDs (each seeking to optimise the different outcomes they are responsible for) can undermine the optimal impact of investments for suicide prevention. Systems modelling provides essential regional decision analysis infrastructure to facilitate coordinated federal and state investments for optimal impacts

    Indigeneity and likelihood of discharge to psychiatric hospital in an Australian deliberate self-poisoning hospital-treated cohort

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    Hospital-treated self-harm rates for Aboriginal and Torres Strait Islander (Indigenous) people are at least double those for other Australians. Despite this, limited research has explored the relationship between Indigeneity and the clinical management of hospital-treated deliberate self-harm. A retrospective clinical cohort study (2003–2012) at a regional referral centre (NSW) for deliberate self-poisoning was used to explore the magnitude and direction of the relationship between Indigeneity and discharge destination (psychiatric hospital vs. other) using a series of logistic regressions. There were 149 (4%) Indigenous and 3697 (96%) non-Indigenous deliberate self-poisoning admissions during the study period. One-third (31%) were referred to the psychiatric hospital at discharge; Indigenous 21% (n = 32) vs. non-Indigenous 32% (n = 1175). Those who identified as Indigenous were less likely to be discharged to the psychiatric hospital, OR 0.59 (0.40–0.87) at the univariate level, with little change after sequential adjustment; and AOR 0.34 (0.21–0.73) in the fully adjusted model. The Indigenous cohort had a lower likelihood of psychiatric hospital discharge even after adjustment for variables associated with discharge to the psychiatric hospital highlighting the need for further investigation of the reasons accounting for this differential pattern of clinical management and the effectiveness of differential after-care allocation

    Elastic stresses can form metamorphic fabrics

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    Detailing the relationship between stress and reactions in metamorphic rocks has been controversial, and much of the debate has centered on theory. Here, we add to this discussion and make a major advance by showing in time-resolved synchrotron microtomography experiments that a reacting and deforming sample experiencing an elastic differential stress produces a fabric orthogonal to the largest principal stress. This fabric forms very early in the reaction and can be shown to be unrelated to strain. The consequences of this are significant because a non-hydrostatic stress state is a very common geological occurrence. Our data provide the basis for new interpretations of the classical, and enigmatic, serpentine fabrics of Val Malenco, Italy, and Cerro del Almirez, Spain, where we relate the reported fabrics to transient, and cyclical, differential stresses from magma intrusion and the earthquake cycle.</jats:p

    A Conditional Zebrafish MITF Mutation Reveals MITF Levels Are Critical for Melanoma Promotion vs. Regression In Vivo

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    The microphthalmia-associated transcription factor (MITF) is the “master melanocyte transcription factor” with a complex role in melanoma. MITF protein levels vary between and within clinical specimens, and amplifications and gain- and loss-of-function mutations have been identified in melanoma. How MITF functions in melanoma development and the effects of targeting MITF in vivo are unknown because MITF levels have not been directly tested in a genetic animal model. Here, we use a temperature-sensitive mitf zebrafish mutant to conditionally control endogenous MITF activity. We show that low levels of endogenous MITF activity are oncogenic with BRAFV600E to promote melanoma that reflects the pathology of the human disease. Remarkably, abrogating MITF activity in BRAFV600Emitf melanoma leads to dramatic tumor regression marked by melanophage infiltration and increased apoptosis. These studies are significant because they show that targeting MITF activity is a potent antitumor mechanism, but also show that caution is required because low levels of wild-type MITF activity are oncogenic

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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